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VOLUME XXXVII. Tae Maneangse-Ore Deposits oF Inna, by L. LeieH Frrmor, A.R.S.M., B.Se. (London), F.G.8., Assistant Supe intendent, Geological Survey of India. Published by order of the Government of India, CALCUTTA : SOLD AT THE OFFICE OF THE GEOLOGICAL SURVEY, 27, CHOWRINGHEE ROAD. LONDON : MESSRS. KEGAN PAUL, TRENCH, TRUBNER & CO. BERLIN : MESSRS, FRIEDLANDER UND SOHN. 1909. i hye a vita tA! I as rah i oe | ' ae * Pe ee TS - , y Pri ; ’ , <0 a (Oe aM Bie ot oan'y rat, 5) AL am ee. ney. on eau Ss Vol ag Cosa oof boilgehay Me a ly gee iN * 1B vk 4 bi m) ne » eae - ay ee bi THE MANGANESE-ORE DEPOSITS OF INDIA CONTENTS dg SUMMARY OF CONTENTS. Detailed Contents . - P List of Plates . List of figures in the text ¢ : List of tables . ; , : é : Synopsis oF PartsI, II, anp IIT, . 2 Part I[.—Introduction and Mineralogy A = . Part II.—Geology (Mode of Occurrence and Origin} Parr IIJ.—Economics and Mining : ¢ : ‘ Part IV.—Description of Deposits. ° ° Apprnpix 1.—Bibliography of Indian Manganese. ApprnpIx II.—Geographical Index. [NDEX. PaaEs. ix—xlvii xlix—liii ly—lvii lix—lx I xiii—-xevii! 1—232 233—408 409-—610 611—1158 ~ owed * a > , ' el OF ye au is ‘ i ; i > ‘ ‘ x 1 Sh ‘ ; ioe ; : , as . u DETAILED CONTENTS. PacE, Synopsis or Parts I, II, anv III - C . » lxv—xevii Parr I. INTRODUCTION AND MINERALOGY, CuarTER I.—Introduction. ‘ History of the investigation . 5 Z 2 : 3 Scope of this Memoir . . 5 6 ; 5 Acknowledgments . . 2 5 ° . - 6 Analytical work . . ° . ° . ° 8 The visitor to India : : ° A 5 9 Literature of Indian manganese-ore deposits . 2 9 Literature of foreign manganese-ore deposits . - 12 Nature of manganese . - > - > - 16 Origin of the word manganese. . . . : 17 Recognition as a new element, : ° . ° 17 Distribution in Nature . . . 5 ° 5 18 In the mineral kingdom . : : 5 c 18 In the vegetable kingdom. : “ 5 e 19 In the animal kingdom. : 5 C 20 CuapTER I].—Mineralogy: General. Wide distribution of manganese in minerals and rocks 21 Colours of manganese minerals : > 5 2] Occurrence of manganese minerals . : : 22 List of known manganese minerals with theis chief properties . . . . . 5 - 23 List of Indian manganese minerals . - : 34 List of associated non—manganiferous minerals . “ 35 New species and varieties 5 4 . A ° 36 Cuaprer Il].—Oxides. Pyrophanite. - é ° S : - : 37 Dysluite ° . . ° ; . . ° 37 < MANGANESE DEPOSITS OF INDIA. CHapreR IIT.—continued. Manganmagnuetite . . : . 5 . Occurrence . : ° ; ‘ : Origin . Hausmannite c : - - = Vredenburgite cC 5 a : : Characters and occurrence - : : ‘ Chemical composition . ; : - S Sitaparite 6 Characters. ; : : ; - Chemical composition Braunite Occurrence é 5 4 - Crystallographic ciencters : . : , Value of the fundamental angle pp’. . - Length of the vertical axis, 0 . . . The Kajlidongri crystals 3 The Kacharwahi crystals . : . Twins . ; ‘ 3 > I Anew form . - “ ° : The Lohdongri oxgetals - : . : The Kodegaon crystal - ° Three new forms 3 6 5 Striations ; ; c 0 Size of crystals é . : 5 List of forms on Indian and foreign braun- ites. 2 Physical characters, Magnetic characters Chemical composition A ppendix—Analysis of Sitapar Eeaunae Polianite . 3 a ; Pyrolusite Characters Occurrence . . ; Analyses é Manganite . > 7 5 - “ “ : Characters . . A 5 : : ° Occurrence . rp : 5 ; 4 Chemical comparmiee Pseudo-manganite . : < - . . PAGE. CONTENTS. Cuaprter III.—concluded. Specimens from Mysoreand Goa ‘ : Comparison of properties of manganite, pseudo- manganite, and pyrolusite . . - . Cuaprer IV.—Manganates and Carbonates. Hollandite Occurrence F Physical characters. 5 Crystallographic characters Fibrous hollandite . Hollandite in the Chhindwara district : ; Hollandite in the ores found in the crystalline limestones, Nagpur district “ 7 Massive hollandite, Balaghat district . ss - Chemical composition . - 5 < : Coronadite . Cc “ 5 5 : 5 Specific gravity . . - ° - 5 Psilomelane . a ; : 2 6 Occurrence . é , 4 4 Physical iarietars, Form . ; C Specific pacity Chemica! composition Descriptions of specimens Guguldoho Avagudem Tekrasai A Calculation of analyses of praneite- -ps loielane ores . Calculated Ree of alercleus Beldongrite . Wad . : Characters Occurrence . ; - - 3 : 5 Chemical composition Garbham specimen . Kodur specimen Ankerite Rhodochrosite Characters Occurrence PAGE. 106 106 106 107 108 110 115 116 116 117 118 121 121 121 122 122 123 xil MANGANESE 1 EPOSITS OF INDIA. PaGE. CuaPTEr V.—-Silicates—Pyroxenes and Amphiboies. Manganese-bearing pyroxenes. - Blanfordite . é 3 . The Kacharwahi occurrence . : 2 2b Original account . : > 5 ° - AZo Crystallographic characters . - 2 > 3126 - 5 - 125 . ° ° «925 The Ramdongri occurrence 5 seg The Kajlidongri occurrence. A yee The Narukot occurrence . c 5 A «zs Manganhedenbergite . : : A . - 130 Occurrence and characters ° - 131 Chemical composition . . c ° - I3l Brown and yellow pyroxenes . . . . * lee Occurrence . 5 cC . . ° 5 BY Composition . . . . 4 5 - 133 Schefferite and urbanite . : . - - 133 Pyroxenes of the Vizagapatam district . ; «137 Brown pyroxene . 2 : é ‘ ~ 157 Green pyroxene . 5 A - - pe ley Brownish green pyroxene : : = oo melo’ Colourless pyroxenes . : - - - 5 BTS Jeffersonite . F : ; “ : : - ws Rhodonite . - 5 : < : > - 139 Characters . c . : 5 < - + 188 Microscopic aspect . - ° . - « ad9 Identification : : “ 5 . 240 Occurrence . - : 2 “ oy a0 Alteration . : C > . 148 Use as an oriieenial stone . - 5 . 14 Manganese-amphiboles . f ¢ “ . 145 Foreign manganiferous araphibsles . - « #l4b Dannemorite . ; : é c « 46 Richterite ° - : . : s 1146 Yellow and greenish-grey amphiboles (Danne- morite) . e c - fe = a) aay Central Provinces . : - > - o eaT Kajlidongri . - “ : : - . 149 Winchite . é : ; , . 149 Occurrence . : - : . 449 Crystallographic chamaeests A * “ <1) E50 Pleochroism . . : ° . . - 162 CuHaprEerR V.—concluded. Extinction angles Double refraction CONTENTS. Separation of the mineral Specific gravity Chemical composition Juddite ‘ CuapteR VI.—Silicates (continued)—Garnets. Manganese-garnets Characters of garnets Composition of garnets . Isomorphous replacement Origin of the term ‘ spandite’ . Use of the term ‘spessartite’” . Origin of the term ‘grandite’ . Analyses of Indian manganese-garnets Spessartite . Occurrence Abundance and economic importance Localities for good crystals Crystallographic characters Cleavage Structure zoning Striations Specific gravity Colour . Colour zoning Inclusions Anomalous double refraction Microscopie aspect Spandite Occurrence Characters Grandite . Aplome : Calderite . Occurrence Chemical composition CuapteR VII.—Silicates (concluded)—Epidotes, Micas, etc. Piedmontite Characters Chemical composition . - . . =I <7 xlv MANGANESE DEPOSITS OF INDIA. CHaptTEeR VII.—concluded. Mangan-epidote . < : = : : Thulite and withamite . f s Distinction between the different engeateroun epidotes : Occurrence in India : : : ; : Characters of Indian piedmontites . c ¢ Ilvaite : 3 : ; é F . ° Carpholite Manganese-micas .« Caswellite . : : ‘ ; 5 7 Alurgite - ° : : : : : Manganchlorite Indian manganese-micas and oilontce Manganchlorite é Brown micas (Menzenagyalie ie Alurgite . : : : é : ‘ e Ottrelite . ‘ F : ‘ E : : Cuaprer VITI.—Titano-silicates, Niobates, Phosphates, and Tungstates. Greenovite , ‘ : ; , Tschefftkinite % ‘ A . 5 Columbite Manganapatite Triplite : c A manganesian phosphate. F : : . Wolfram 3 Characters . . Z : 5 ‘ Occurrence in India CHAPTER 1X.— Associated Non-manganiferous Minerals. Graphite r ; : Chalcopyrite Pyrite Pyrrhotite ; Halite : : 3 : ; é Rose quartz . ‘ Amethyst ; Chalcedony and chert, Opal c - Tron-ores F Hematite . ; ; ; - Limonite : : CONTENTS. CHAPTER 1X.—concluded. Magnetite Martite Gibbsite Microcline : ; 2 : : 5 Sapphirine . : . - ° : : 0 Lithomarge and kaolin . - : : ‘ Arsenates ; The Sitapar av come : The Kajlidongri arsenates Distinction of arsenates, apatite, and raien Barytes 5 CoapteR X.—Tho Identification a neenen Goa: Minerals: Micaceous structure Colour . Tests for matganese : 2 : : The black or grey minerals Key to the identification of the black ae dark: “grey iron, manganese, and chromium minerals. Key to the identification of the black, dark- “Bre, and bronze-coloured mangafese-ores White minerals - . 3 : 5 : 5 PART II. GROLOGY (MODE OF OCCURRENCE AND ORIGIN). CuaPTER XI.—General. General The Archean complex The oldest gneisses The schistose gneisses and the Diécw wars The plutonic intrusives uedsikeent granite, charnockite series, etc.) The great eparchzean unconformity . The Purana formations . Classification of the pre-Cambrian Derivation of the rocks ranging in age from Cambrian to recent . : : The ultimate source of the manganese-ores Manganese-ore deposits found in rocks of any age Distribution of the manganese-ores and minerals of India according to formations The Khondalite Series . Vizagapatam, Ganjam, and Orissa 235 235 236 236 237 237 238 238 238 239 239 239 241 241 XVi MANGANESE DEPOSITS OF INDIA. PaGeE. CuaPTeR XIl—The Kodurite Series of Vizagapatam and Ganjam. Vizagapatam district . : : : ; . 243 The calcareous or cale-gneisses . - : . 243 The kodurite series. é : . 244 Relations of the kodurite series to ih athat crystallines : : - : : . 244 The kodurite series of igneous origin . : - 247 Nomenclature of the kodurite series . - = 17249 Pegmatite and vein quartz c c - . 250 Minerals of the kodurite series . . A ; 1250 Quartz i , , " ‘ é .) 25 Felspar . a : ° c - 251 Apatite. < o : : ¢ . 251 Spandite . : : é , ~ = 2 xil Manganese-pyroxenes . ; : < - 252 Biotite 2 c - : . c oe Graphite . c : - = 6 - 252 Sphene. . - < F c : - 252 Manganmagnetite : 5 ; - 253 Petrology of the kodurite series < C . 253 Magmatic differentiation of the series . . 254 Localities for rocks of the series. : - 254 Ganjam district . A c c 7 - 255 Chemical composition of Kodsinite : : A on 206) CuarpteR XIIl._—The Kodurite Series—concluded. The Alteration of the Kodurite Series and the Forma- tion of Manganese-ores : o n - 262 The replacement of quartz : : c . 263 The alteration of the felspar . : . - 263 The formation of chert and opai : 5 - 263 Potash removed in solution as carbonate . - 264 Alteration and replacement of apatite 3 . 264 Replacement of spandite. : . . 265 Alteration of spandite . ° 265 Formation of manganese-ores by se ade cub of the kodurite rocks - : é - 266 Replacement of the non-manganiferous ponetient 266 Minerals replaced by manganese-ore . ° 2 Or The removal of alumina . ° : . - 268 Replacement of the manganiferous varieties . 268 CuartmR XIII.—concluded. CONTENTS, Formation of manganese-ores by alteration i situ of manganese-silicate-rocks . ° 5 Alteration took place under oxidizing conditions . The removal of the alumina. . ° A The ores formed in three ways . : Ferric oxide in the ores . : Baryta in the ores . ¢ 5 6 : Comparison with the Brazilian diioaits 5 4 The Depths to which the Manganese-ores extend Kaolinization : 5 Oxidation . The zone of fracture and belt of Shathioing Ground-water level. : = Time of formation of ores Depths to which the ores extend Sources of the carbon dioxide . CoarpreR XIV.—The Manganiferous Rocks of the Dharwar Facies, including the Gondite Series. General The Dharwar peHou of eetiaientation The metamorphism of the sediments The Transitions The Champaner series The Dharwar series The Chilpi Ghat series The metamorphic and onpsialline complee of the Nagpur-Balaghat area . The Aravalli series . The equivalence of the various series ‘Champaner’ the prior term ‘Dharwar’ the most familiar term The term ‘ Dharwar’ adopted . The Deposition of the Manganiferous Sediventa of the Dharwar Period The source of the manganese The Partial Metamorphism of the Mantaniforous Sediments 5 5 5 Formation of primary ores Localities for primary ores : : Formation of outcrop or recent secondary ores (lateritoid) ores . : ° - Localities for outcrop secondary ores : 5 XViil MANGANESE DEPOSITS OF INDIA, CHAPTER XIV.—concluded. PaGe. The More Complete Metamorphism of the Dharwars . 288 Primary manganese-ores formed by the metamor- phism of manganese-oxide sediments < . 288 Formation of the manganese silicates, spessartite and rhodonite, in the ore-bodies . : 289 Liberation of water, oxygen, and rarely of btben dioxide : A - é : ° Pee!) Formation of manganese silicates at the peripher- ies of deposits. 3 - <1 292 The banded structure of the ore Ssiotiion is ; 282 Apatite : : ones The Alteration of the Marageitosans Silicates a . 293 Re-conversion of spessartite and rhodonite into oxidized ores (deep secondary ores) : Bash: Time of alteration of the manganese silicates “i, 1294 Method of alteration of the manganese silicates . 295 Mineral Veins and Intrusives . : E « _ 296 Percolation of mineralized waters during the meta- morphism of the ore-bodies . c : . 296 Veins traversing the ore-bodies 3 : - 296 Rocks intrusive in the ore-bodies - - . 296 Manganese-ores in Crystalline Limestones . - . 297 Dharwars in the Chhindwara district . : Re ihe: Origin of the quartz-pyroxene-gneisses and crys- talline limestones : : : Us Origin of the manganiferous fenoepiics . - 300 Piedmontite-gneisses : - . 301 Theory of formation of the aniintrer oun lime- stones : - : : - =» 301 Formation of piedmontite, serait and rhodo- nite . - - : - 302 Nodules of manganese-ore and A Oie. . 302 Alteration of manganiferous limestones . . 303 Secondary formation of pyrolusite . : . 303 Manganiferous cherts : = - . 303 The mineral composition of the manganese-ores . 303 Folding and faulting of the manganese-ore bands 304 Classification of the Manganese-ores associated with the Dhdrwar Series . : 2 : “ =. 304 CHAPTER XV.—The Gondite Series. General F é z . : s P . 806 Origin of the name . : : : ; 306 CONTENTS. X1x PaGE, CHAPTER XV.—concluded. Application of the name . - - 5 . 306 Areas in which found - : : 2 - 307 The Nagpur-Balaghat area 5 - - - 307 The Origin of the Gondite Series 5 aide! Evidence for igneous origin of the eondits series. 309 Evidence for metamorphic origin of the series . 310 The rocks at Balaghat and Ukua - : . dll Conglomeratic grit converted into gneiss. 3li Mica-schists and Bais of Bhandara and Balé- ghat . : : ns sols The ‘country ’ of the series - : : . 314 Main conclusions as to origin . : : Sols The shape of the areas of deposition . - - 315 The number of ore-horizons. 316 Deposition took place in lagoon- or Take: like areas 318 Some ore-lenticles due to squeezing and some to deposition in basin-shaped areas. 318 Prospecting for manganese-ore at the hase of tite Chilpis - A - 5 5 aly) The Gondite Series in shaban? : : 5 5 alg) The Gondite Series in Narukot 5 > 320 Alteration of manganese silicates to manganese - ores took place in Archean times . - » 2! CHaPTteR XAVI.—The Gondite Series—continued. Mineralogy of the Gondite Series. : 5 5 aR Petrology of the Gondite Series ; : : - 325 Nomenclature of the gondite series. ozo Structure of the bodies of manganese- feaing rocks < . - 9326 Dip of the bands of the condita: series , 328 Dimensions of the masses and bands of the ponciia series : : “ : ° . - 328 Lists of rocks : ; c - 329 Rocks found in the sondlite series as repre- sented in the Central Provinces : - 329 Rocks found in the series as represented in Jhabua c - - - 330 Rocks of the series found in ENTREE - - 330 Rocks of the series containing braunite - deal xx MANGANESE D&POSITS OF INDIA. PAUE. CHAPTER XVI.—concluded. Petrology of the Gondite Series—concluded. Rocks interbanded with the rocks of the gondite series in the Central Provinces . 332 Rocks interbanded with the rocks of the gondite series in Jhabua : - “aoe Rocks interbanded with the gondite series in Narukot : - - - doa Manganiferous micaceous aohicts aseccinkea with the rocks of the gondite series . . 333 Winchite-bearing rocks. : - - 334 Manganiferous rocks forming the ‘country’ of the gondite series - A A - 304 Non-manganiferous rocks forming the ‘country’ of the gondite series in the Central Provinces . : - - 3D Rocks intrusive in the gondite series . 336 Mineral veins found traversing the rocks of the gondite series . : . : - oab Descriptions of more important rocks . - 337 Gondite . : - : - - Soon Apatite-gondite . - : 339 Rhodonite-bearing members of wis series 339 Barytes in the gondite series : -. 339 Rhodonite-quartz-rock and rhodonite- gondite . : 340 Amphibole-bearing mabe of ike series 341 Rhodochrosite in the gondite series . 341 Felspar in the gondite series. - 341 Piedmontite, calcite, and wollastonite, in the gondite series. : : 7 oat Arsenates in the gondite series. . 3842 Pyroxenes in the gondite series. - 342 Blanfordite “ - 5 . 343 Black quartzite . : : : . 343 Red quartzite . ° : : . 344 Manganiferous gneisses 344 Localities for the Rocks of the Gondite Saves 345 Areas to prospect for further occurrences of the gondite series : . . 346 OONTENTS, CuarterR XVII.—The Gondite Series—concluded. Chemical Composition of the Gondite Series ° . Composition of gondite . : * 5 : Composition of rhodonite-quartz-rock ; ; Alteration of the Gondite Series - : . Evidence pointing to the formation of manganese- ore by the alteration of spessartite and rhodo- nite . : : . - . The Manas deans : : . Association of manganese-ore ad spessartite Spessartite changes to manganese-ore . Alteration of rhodonite . 5 . Time of alteration of the manganese-silicate- Soaks into maNganese-ores . . - . : Hill deposits are dry . . . Highest points of a gondite hand sonaiet of manganese-ore . : 5 Manganese-ore deposits formed betore ae present topography . . . . Probably formed in Archean times’. The way in which the manganese- eg cross alter to manganese-ores - : The formation of braunite and palonielans . The ores are not porous The ores formed by combined a igcament and decomposition of spessartite and rhodonite . : - : . Lack of examples showing Sinton of man- ganese . . . = z Carbon dioxide as the aient producing alteration Sulphuric acid as itis econ eee alteration . 5 “ . : Alteration of shodanite Carbon dioxide the more probable reap Rarity of open spaces in the altered rocks Further reasons for supposing that alteration took place in Archean times . Depths to which the manganese-ores extend Conclusions as to the Origin of the Gondite Series and the Associated Manganese-ores_ . . 5 . xxl PAGE. 359 XX MANGANESE DEPOSITS OF INDIA. , CuapTeR XVIII.—Manganese in the Purdna, Paleozoic, and Mesozoic Formations. Manganese in the Purana Formations : - . Manganese in the Kaladgi formation . - : Manganese in the Bija4war formation . ° . Manganese in the Vindhyan formation - < Manganese in the Krol formation - Manganese in the Gondwanas . Tronstone shales. : . c 4 5 Kamthi group : : - 4 5 5 Jabalpur group : . ~ Manganese in the Lias Manganese in the Lametas Manganese in the Deccan Trap Cuarrer XIX.--Manganese in Laterite. General F ° : Origin of the term : < Division into low- and high- Slovel \atenites : : Low-level Laterite. Manganese-ore in low- jewel laterite High-level Laterite : : South Indian variety of rere iovel interae é Deccan variety of high-level laterite . - c Theories as to the Origin of High-level Laterite. . The Laterite of the Yeruli Plateau . : - c A bauxite-conglomerate . : The conglomerate formed beneath mater sigh as in a lake Composition . é : : : . Origin of the Yeruli ishorite Necessity of considering each occurrence of laterite separately Lateritic Manganese-ores : 3 . : 5 Result of formation of laterite. : 5 : The destination of manganese when laterite is formed : . : - F - : Lateritoid . é : : : ; ; The Talevadi occurrence . : F A ° Jabalpur and Goa . : 5 c Classification of the deposits of lateritic manga nese-ores . . . . . . Economic value of the deposits - : PAGE. 366 366 366 367 367 367 367 367 367 368 368 369 370 370 370 370 371 371 372 372 373 374 375 375 376 379 380 380 380 380 381 383 384 385 385 CONTENTS. Xxill PaGE CuaprTerR XIX.—concluded. The Sandur deposits 3 5 5 : - 386 Limitation of the term Pench . 3 : . 395 Manganese oxide deposited ina oped near Rambha . 5 5 5 5 5 oEls) Pyrolusite at Pan Kuan . : : . 396 Dendrites of manganese oxides . 5 5. ee Manganese oxides in Pleistocene mammalian remains at Allahabad . - : - 397 ° Manganese-oxide stains in asbestcs from Tumkhera Khurd . 5 - 398 Deep-sea Deposits . : - 6 : - 398 Summary of origin of deep-sea nodules 403 Deep-sea nodules from the Maldive Islands. 403 Manganiferous Sands and Soils : 3 . 404 12 XXLY MANGANESE DEPOSITS OF INDIA. CHAPTER XX.—concluded. Manganese in fault-rock of various ages . < . Manganese-ore in breccias in Central India and the Central Provinces . - - ; Manganese-ore in fault-rock, Bundi State . 5 PART III. ECONOMICS AND MINING. CHAPTER XXI.~-History of the Indian Manganese Industry. General. The working of manganese-ores by the natives of India. - ° ; B 3 : Vernacular names for manganese-ore. . : History of the fluctuations in the price of man- ganese-ore . a . . History of the Modern Manganese Tndusiny in India, Madras . . ° Vizagapatam : i. G. Syne ame the Vizia- nagram, Mining Co., Ltd. ° : : Gordon, Woodroffe & Co., Kovoori Basivi- reddy, and A, Subha Naidu and Co, : Madras Manganese Co. and the Bobbili Mining Co., Ltd. Sandur State: Messrs. A. Ghee. Téa Co,, and the General Sandur Mining Co,, Ltd. . . . . . ‘ : The Central Provinces . . W. H, Clark, H. Dodd, and the Central Provinces Prospecting Syndicate, Ltd. (Nagpur, Baélagh4t, and Bhandara) . es H. D. Coggan, Jambon & Co,, and the Cen- tral India Mining Co., Ltd. (Nagpur and Bhandara) . F ‘ A. ae Gow Smith and the Taaten Manganese »., Ltd. (Nagpur and Chhindwara) . : Pssst & Co, (Nagpur and Bhandara). . Cooverjee Bhoja and the Madhu Lall Doogar Mining Syndicate (Nagpur) . : . PaGe. 404 404 405 422 423 CONTENTS, CHAPTER X XI.—concluded. Central Provinces—concluded, Bansi Lall Mining Syndicate (Négpw). P. C. Dutt, Burn & Co., the Carnegie Steel Co., and Tat. Sons & Co, (Balaghat) ° Mathura Prasad (Chhindwara) . ° . D, Laxminarayan (Nagpur, Bhandara, and Balaghat) . : ’ . ‘ A Central India. : c ; ° . e Kiddle, Reeve & Co. (Jhabua) . ‘ 0 Bengal . 4 : : : : ° 6 Heare, Miller & Co., Jambon & Co., and the Madhu lLall Doogar Mining Syndicate (Singhbhum) ° : : . : Bombay . . : : : d Lame B35 Heentharia, “Tambor & Co., and C. P. Boyce (Belgaum) . . ° . T. B. Kantharia and the Shivrajpur Syndi- cate, Ltd. (Panch Mahals) : 5 The Bamankua Manganese Co., Ltd. (Panch Mahals) : ° : - ¢ f Mysore . W. Ainslie, T. ts Wemnold and the My: sore Geological Department . W. T. Hamilton Holmes and the Meare Manganese Co., Ltd. (Shimoga) : The New Mysore Manganese Co., Ltd. (Shimoga) . : The Peninsular Minerals Co. of Mysore; Ltd. (Tumkur and Chitaldrug) : : Miss A. I, Dawson and the Shimoga Merion ese Co., Ltd, (Shimoga and Kadur) . Other concessionaires 9 : CuspTeR XXII.—Statistics of Production of Manganess-oro in India. Sources of information : : Detailed tables of production . : : Deposits that have yielded over 100,000 tne Comparison of prices with figures of production . Comparison of Indian and foreign manganese-ore production . : : ‘ ° ° . Exports of Indian manganese-ore . ° . XXV1 MANGANESE DEPOSITS OF INDIA. CuapreR XXII.—concluded. Distribution of the exported Indian manganese- Orem, : : ; : : - . Future Prospects of the Manganese Industry in India. Appendix to Chapter XXII. - : Indian production figures for 1907. : : CuapTER XXIIJ.—Labour and Costs of Production. Labour 2 - - . 4 - . . Labour obtainable . : - - : Coolie wages . : - . “ Contract and daperuiantal tsbour A é Absence of mining castes. - Average daily number of workers. 5 . Benefits of the manganese industry . . . Costs of Mining and Transport 5 . . . Cost of mining . A . ° : Cost of transport to malvern . . ° . Cost of railway transport to port of shipment Cost of handling at the port of shipment . Bombay . . - c . . . Calcutta . : - a - . . Vizagapatam . - : . . e Mormugao - “ ° ° . Cost of shipping to maore and America. Insurance - : - : ‘ ° . Destination charges. - - - ° Total costs of mining manganese-ore in India ah delivering it c.7.f. at foreign ports . : Comparison of the costs of production of Brazi- lien, Russian, and Indian ores 4 é Royalty . ° ° . : . . CuapTER XXiV.—Valuation and Chemical Composition of Manganese-ores. Valuation of Manganese-ores . : ° : Mining Journal prices. : : Schedule of the Carnegie Steel Co. : Requirements made less stringent during 1906 . Use of the Vizagapatam ores. . . 2 Special prices . . ‘ A : . . Valuation of ores for chemical purposes « ; Pace, 456 457 459 459 467 467 468 468 469 470 471 472 473 475 479 481 481 482 482 483 483 484 484 485 487 489 494 494 495 495 497 497 497 CONTENTS. Cuarrer XXIV.—concluded. Nomenclature of manganese-ores and manganifer- ous iron-ores . . . . Ferruginous manganese-ores Analyses of Indian Manganese-ores . The Tables of analyses . ; ; : ° : Summary of tables of analyses . Analyses of Indian ores expected by a Analyses of the manganese-ores of th2 world Analyses of cargoes of Indian and foreign ores landed at Middlesborough Analyses of the manganese-ores of the world Rarer Constituents of Indian Manganess-ores Alumina _ Baryta . Lime. f - : é ¢ 5 5 Magnesia : : : : : Potash . ‘ : 5 ; 7 : : Soda . z : ‘ ‘ ‘ : : Arsenic . - 5 5 Sulphur Cobalt and aickel : : Copper . : ° : : : c : Lead. 5 5 ; : 2 ; Zinc : : = ; 4 C - 7 Titanium - ' _ Combined water. : 5 c CuapTeR X XV.—Value of the Indian Manganese-ore Production. Carbon dioxide Official Indian statistics . A . = The f.0.b. or export value is the true va'ue to India : : é : : 5 Tables of export sain The c.7.f. or true market value . : Comparison of India’s manganese-ore protection with that of other minerals - The ferro-manganese value of the Indian mangan- ese-ore production : : - Prices of ferro-manganese. : Taking the ferro-manganese value, the indian manganese-ore production is about equal in value to that of coal. : : 541 XXVili MANGANESE DEPOSITS OF INDIA. PaGE CHAPTER XXV.—concluded. Enormous joss to India through not manufactur- ing ferro-manganese . - < . . 541 CuapreR XXVI.—The Mining or Quarrying of Manganese-ores. General Principles for deciding whether to Mine or Quarry a Deposit : = é ome 2020 Mode of occurrence and teens of fie deposit . 546 Depths to which manganese-ores extend . . 546 Relation of the outcrop of the deposit to the topography . 6 - - 5 - - 548 The value of the ores : ° ° - 548 Nature of the « country’ of the deposit . - 549 The presence of water . : . . - 550 Cost of timber, tools and plant . ° : . 5650 Cost of labour. . . . . - 550 Cost of employing technically- tnaihed managers . 5651 Tbe Way to Prospect a Manganese-ore Deposit . . ool The Way to Work a Deposit . . 5 . . 5538 Four mistakes to be avoided . : - 554 Thick ore-band of moderate dip forming a hill - 555 Thick ore-band of steep dip forming a hill . . 557 Thin ore-band in a hill. : - - 558 Thick ore-band cropping out on low eatted - 558 Thin ore-band cropping out on low ground . - 559 Scattered ore-bodies in lithomarge . é . 560 Lateritoid cappings . : e : . . 562 Deposits of detrital ore or talus-ore . . - 568 CuaPtER XXVII.—The Mining or Quarrying of Manganese-ores —concluded, The Methods Actually Used in io the Indian Manganese-ore Deposits . ° 567 Indian manganese quarries Lpalty mines . . 568 Classification of deposits. - . 568 Brief description of methods of mean Indian manganese-ore deposits ‘ : : - 570 Gravity-inclines and aérial ropeways. . - 570 Mining tramways and railways. . . ».- Bek Sampling . - - . =. 4 O0L Deposits often padlg womkad ‘ : . . 572 Waste of smalls and dust . . o "Kole Waste of low-grade and siliceous lump ores . 673 Use of manganese as anoxidizer . CONTENTS. CuaPpTeER XXVII.—concluded. Possibility of washing, eae and briquetting smalls and fines . Methods of Mining, Washing, seal se 5 aged Abroad Briquetting in Brazil : ‘ Z Hydraulicking and washing at Ghee in Virginia Methods of mining, washing, etc., employed in Panama . : . : Mining of manganese-ore depamtae in other See of the world Grant of Mineral Concessions in India ‘ ‘ CuapTER XXVIII.—The Uses of Manganese. Uses in Metallurgy History of the application of eae iets in the iron and steel industry Spiegeleisen and ferro-manganese_. : ° Manufacture of spiegeleisen and ferro-manganese. Manufacture of ferro-manganese in India . Use of spiegeleisen and ferro-manganese . 3 Quantity of manganese required in the manufac- ture of steel : . 5 Phosphorus and silicon in soieaclelaen and fen. manganese. - . : : ° Use of the Indian phosphoric ores . 5 a Use of manganese for de-sulphurizing Manganese in foundry practice. Manganese-steel Effects of manganese on iron and ag Other manganese alloys . Silicon-spiegel . Manganese-bronze . Metallic manganese 4 - ; The smelting of manganese-ores by the natives of India . ° 5 Kheri . 5 . . . For the decolourization of glass ; For bleaching powder, bullion melting, and potassium permanganate . . Xxx MANGANESE DEPOSITS OF INDIA. CHarTER XXVIII.—concluded. CuaPTER XXIX.—Andaman Islands, Baluchistan, and Bengal. Use of manganese as a colouring material - z For colouring glasses and enamels . > . For pottery . 2 ; : : : : Ornamental applications APPENDIX TO PARTS I, II, AND III, List of atomic weights . - ° . . Table showing composition of certain manganese minerals . : ° : - List showing composition of certain manganese minerals in terms of oxides ; : . List of factors for psilomelane and holandits : : Figures for the conversion of phosphoric oxide into phosphorus : - . - 3 A : Miscellaneous factors . ; - : . Tons and poods . . - . 5 - - PART IV. DESCRIPTIONS OF DEPOSITS. Andaman Islands . : 2 F : ‘ A Baluchistan 4 : ; : . ~ Bengal ; A : . . ; ° Burdwan District . : : - Gangpur State Hazaribagh District Kalahandi State . Manbhum District . Monghyr District . - : . : . Morbhanj State Puri District. - - : Singhbhum District - ; History . Geology _. : : Mode of occurrence of thes ores . : : Origin of the ores . ‘ A ‘ : Source of the manganese . - ° . Time of formation of the ores . ; ‘ PaGeE, 601 601 602 604 605 606 606 608 609 610 810 613 613 614 614 615 615 616 617 617 617 618 618 618 619 619 620 620 621 CONTENTS. Cuaprrr X X1X.—concluded. Commercial value of the~ deposits, and analyses of the ores Output . : List of localities 5 : ; . . 1. Purana Chaibisa . 2. Kamarhatu . : : 3. Matkamhatu : : : é 4. Tekrasai = ‘ - , : 5. Gitilpi . ; : 6. Kalenda : : 7. Tutugutu. - : - 8. Bistampur . : : . 9. Lagia ; 5 A 10. Leda Hill The 24-Parganas Cuaprrr XXX.—Bombay Presidency. Belgaum District 1. Munnikerri : : : - 2. Bhimgad . : : 5 : 3. Talevadi . - : : Mode of occurrence and origin Gibbsite - 4, Nersa & : Bijapur District ‘Ingleswara : . : ° ° Bagalkot and Kaladgi ; 3 5 Dharwar District . - ; . 1, Tawargatti : : . - - 2, Nagargali . 5 * . . . Dharwar District (Sangli State). : . Historical - 5 c . . . Situation of thedeposits . . = : Chik-Vadvati and Kelur . 5 . 5 Hamigi . : : 5 . . Shirhatti 5 - ° : . 5 Narukot State, Rewa Kantha Agency - Situation 5 > : 5 ° 5 Mode of occurrence . . ° . c Time of alteration of manganese silicates to ores. z ; : : ° 5 XXxl Paan. 621 622 623 623 623 623 625 626 628 628 629 630 630 631 633 633 634 635 635 639 639 640 640 640 641 642 642 642 642 644 644 646 646 646 646 646 647 XXXIl MANGANESE DEPOSITS OF INDIA. CHAPTER XXX.—concluded. Minerals found ‘ 2 : Rocks found . é : Granite veins . A “ C North Kanara District . ° . Palanpur State : : . Panch Mahdls District . “ History . . * . Geology : - : . Origin of the ores. . 5 Source of the manganese . : Nature and quality of the ores . Economic value of the deposits Descriptions of deposits . : Sivarajpur. 4 - 5 Road section . 3 ° - Manganized slates . : : Rajpipla State : . : Ratnagiri District . 2 : ‘ Satara District 5 C : ; History ° - 5 Geology “ - : - Localities : . 5 5 Mode of occurrence and origin . Nature and quality of the ores . Economic value ' . z Waral or Mulwi . - % 1. Lingméla . c . 2. Bhekauli . ° 3. Chikhli. : . 4. Yeruli C : ° ; 11. Khanapur . é ° Cuaprer XXXI.—Burma and Central India. Burma : . : : Amherst District . * Hantha-wadi District Magwe District Mergui District . Myingyan District . : ° . Ruby Mines D'strict . . . Sagaing District . ; Z CONTENTS. Xxxiil Pace. CHaprerR XX XI.—continued. Salwin Hill Tracts . . s A : 5 (pitt Taung-ngu District : - - : 5 el! Tavoy District : - = A é a (yl! Central India - - : ; ; : 5 Ge Bhopal State . : : - - : 5 (ay The Dhar Forest . A : 5 1, Hill 925 ft., Rane 5 : ; - 673 2, Ratagarh . ; : : 0 . 674 3. Hill 888 ft. (S,W. of) . : : - 674 4, Katotia - : ‘ 3 ; eG 14: 5. Pola Khal~ . ; . . : . 674 6, Kheria Kund : : ; ; 5 rls 7. Pan Kian . : : . 5 5 Ors Gwalior State ‘ ; 2 : : GG Indore State . 3 : : 6 - 676 1, Near Katkut ° . ° ° OuG 2. The Kanar River . é ‘ j 5 hy 3. Barel . A : A a — (O77) 4. Bhamar ‘ is 5 5 (are Jhabua State ; - 5 ‘ ; 7 678 History . - : . ° ; - 678 Geology . . : : - : - 678 1, Kajiidongri . : : : - 679 Mode of occurrence of ore , : 679 Country . < A : - 680 Origin. . - 681 Nature and quality of the ores, - 682 Labour . : : » 685 Mineralogy of the Beposit : : - 685 Braunite . . . . » 685 Hollandite : 6 » 685 Winchite and blanfordite z - 686 Rhodonite . F : . - 686 Spessartite. f . - 686 Carpholite . . 5 : » 687 Hematite . : : - - 687 Piedmontite 5 4 : - 687 Crimson mica. A : GSI Barytes , < : : - 687 Arsenates . 3 ' : c 687 MANGANES£& DEPOSITS OF INDIA, CuapTEeR XX XI.—concluded. 2. Rambhapur - : : . . 3. Amlamal . : ; 8 5. Tumdia 4 3 5 2 C 6, Pitol . 6G = 5 : ihe Nagankhori Mandl ' Rewah State : ‘ : ; : 2 ChartER XXXII.—The Central Provinces—Amraoti and Balaghat Districts. Amrdoti District . Balaghat District . History Physical tes aad ecology of ike mane nese-ore belt * F List of deposits . Nature and quality of the ores . , Communications and transport. 1. Chandadoh 5 : 2. Thirori, Ponia, and Témntapéni (with Géraghét) Pan : . : : Thirori, North Hillocks . = : ; Do. West Hill . : : : . Do. East Hill . ; - : . Do, South Hill . : : : . Jamrapani. . Martite and fanhsite . Garaghat : : . Nature and quality of the ores . : : The working of the deposit - . . Output . : 3. Sonegdon . : 4, Arjoniand Jam. . = 5, Nandgaon 6. Ramrama . n Constitution of the ore-band Nature and quality of the ores . The working of the deposit Output . : ° 7. Katangjheri I (Government Forest) 8. Katangjheri II (Malguzari) . 8a, Other localities ; . CONTENTS. CHaprerR XX XIT.—concluded. Bakoda . 5 : , ‘ Paleolith of manganese-ore from Bdbada : 9, Balaghat (Bharweli, Hirapur, and Manegaon) . History . 6 - : : Geology . ‘ : Red and black quanutes ‘ Length of the deposit Width of the deposit Description of the ore-band: genenal’ . The Bharweli portion The Hirapur portion The Manegacn portion . Nature and quality of the ores . The working of the deposit Output 4 9a. Laugur 10. Ghondi : 11. Ukua, Gudma, and Samlapur : : Length and situation of the ore-band . Dip : é ° : Thickness of ore- ioe ‘Country’ . ° “ 5 Character of the ore- baad: : Nature and quality of the ores The working of the deposit Output . ; Other localities 12, Dharampur 13. Kanaridha 14, Jairdsi . : A 6 - 15. Kurthitola . - : : Parsatola (Borapabar) . : : . 16. Dharpiwara : : - c Bodraghat . : - : : : OnapTeR XXXITI.—The Central Provinces—Bhandara District. History Output and ieBour : : Physical characters and g: doleey of the ore- tee. List of deposits . P : ‘ XXXVi MANGANESE DEPOSITS OF INDIA. CHAPTER XX XIII.—concluded. CuartER XXXIV.—Tho Central Provinces—Chhindwara Dis- Nature and quality of the ores Communications and transport 1. Kosumbah ‘ Pyroxene-microcline -rock 2. Sitapathir Brown manganese-pyroxene Manganese-micas Spessartite in pegmatite , 3. Sukli : 4. Hatora 5. Miragpur. : . 6. Mohugéon Ghat : ° 7. Pandarwani . . 8. Salebaddi 9. Chikhla IT c 10. Kurmura (Ponwar Dongri). Manganese-ore pisolites Chikhla I A sapphirine-bearing doe 12, Sitasdongi Ottrelite 13. Asalpani I 13a. Asalpani IT (Saya Hurki) 14. Pachara . : 11, —_ trict. History Geology List of deposits C Nature and quality of the ores Communications and transport 1. Kachi Dhana 2. Lakhanwara 3. Gaimukh. 4, Sitapar 5. Bichua 6. Alesur : 7: Devi : ° 8, Ghoti Paae. 735 736 736 737 739 740 740 740 742 744 745 750 750 750 750 751 755 755 757 760 763 763 765 767 770 771 771 772 773 773 780 781 785 789 790 790 792 CONTENTS. CHAPTER XXXIV.—concluded. 9. Wagora . - F : ; ° ° ° 10. Gowari Warhona E : A 4 ; 5 11, Dudhara . : é : : ‘ - CuarTtER XXXV—The Central Provinces—Hoshangibad and Jabalpur Districts. Hoshangabad District Sontulai . C : Jabalpur District . > History . A Geology . - : The Sihora beds Hematite-jaspers Manganiferous hematite Psilomelane. - Source of the manganese Formation of the ores Gosalpur quartzites . Pyrolusite Manganiferous limonite Lateritoid Manganese in laterite Economic value of the deposits . List of localities Emelia . . Hardua Khurd Kuan . : . Bara Chhapra . Kasai Hill Darshani - Ponra Hill . Chhota Chhapra . Mansakra . Sihora . Mangela. SOD IPM P oo dO — ~ . 12. Ghogra and 13. Dha nwahi 14, Kurru (Kuro) . 15. Lora Hill 4 16. Sakri . : 17. Khatola. F - 18. Paharewa MANGANESE DEPOSITS OF INDIA. CHAPTER XXXV.—concluded. 19. Deori . : : . 20. Mangeli . 21. Daroli 22. Hargarh 23. Bhatadon 24, Muret 25. Naigain . 26. Chandnota 27. Dhangéon 28. Kailwas . 29. Chindamanf 30. Gosalpur 31. Dharampura 32. Hirdenagar 33. Marhasan 34. Keolari - 35. Nargaon : 36. Pararia (Pandaria) . 37. Nonsar . 38. Gangai . CuapTtER XXXVI.—The Central Provinces—Nagpur District; with the Nimar, Seoni, and Wun Districts. Nagpur District . History. . = Output and labour . Geology 2 - : Physical characters of the country Classification of the deposits Nature and quality of the ores. Communications and transport. Group I : c : 1. Kodegaon . A Opal Fyrite 2. Gumgaon 3. Ramdoneri . Blanfordite Group II 4. Risdra 5. Nandgondi . 6, Sitagondi . : CONTENTS. Craprer XXXV1.— continued. Group WI. 4 6 5 . 7. Kandri - “ Geology of the “apoatt 2 Slickensides grooving. An interesting rock . Nature and quality of the ores The working of the deposit . Output . : . Talus-ore deposits . 6 8. Mansar 5 ‘ 5 Kamthi Lady rit : . Satara pits 5 ‘ Red ochre 5 c ° 9. Mansar Extension ° Hematite 10. Parsoda - : 11. Borda 3 ; . - GroupIV_. : : 12. Parsioni and ee 13. Dumri Kalan 14. Satak : : Satak I. : : Satak IT : Felspathic intrusions 15. Beldongri : Felspathic pibustons c 16. Nagardhan . 17. Nandapuri . 18. Lohdongri . ; : Spaces in the ore-body . Braunite crystals . 5 5 19. Kacharwahi i ‘ Blanfordite, braunite, and albite 20. Waregaon . c : A Spessartite crystals . . 21. Khandala . : : é Manganese-laterite . ° Group V._ : 3 “ : 22, Mandri. . . . An experiment in cleaning 22 xl MANGANESE DEPOSITS OF INDIA, CHaptrR XX XVI.—concluded. 22A. Panchala - - 23. Manegaon . : : e ° 24, Guguldoho . ; : . ° 25. Bhandarbori - ° Group VI. 7 : - - > 26. Mohugaon . 2 : . : PARES Ve - . Piedmontite wa piedmontie -gneiss Pyrolusite : : - 28, Ghogara (Pench River) Piedmontite . : - The Mandvi Bir-Junapani basa - c 29. Mandvi Bir - : ° 30. Junawani . : : 2 - 31. Junapani . : . ° The Kaskuri ade = . : The Bhanadeo band . : 32. Rajkota - 3 : : is Nimar District. E E 2 A : 1, Chandgarh . : 5 > : 2. Jamdihi Nala 3. Bankuta . ° Seoni District F - E ~ - Wun (Yeotmal) District . . ° : CuHarter XXXVII.—Cocrg, Goa, Haidardbad, and Kashmir. Coorg . : - ; s : : Gos) : : - 2 - - History . : - * - A The grant of concessions in Goa . ° Geology . . = . . : Origin of theores . - - Nature and quality of He ores. Extent of the deposits : - Communications and transport . ° 1. Fanuswadi : : . 2. Dab Dabba I 3. Dab Dabba II Other deposits . = . Vaotin . - - - : CONTENTS. CHarTteR XXX VII.—concluded. Kandiapar - ° : - Malan, Villian, Kumari, Bal Kajri 2 - Haidarabad . . ‘ : Fs e s é Kashmir < s F - 2 A 5 CuapTer XX XVIII —Madras Presidency—Bellary District and Sandur State. Bellary District . : . - : 1. The Dharwar- Shiniopa, hark ; , : 2. The Dambal-Chiknayakanhalli band 3. Sandur-Copper Mountain band . . : Bellary District (Sandur State) : . ° History - - : - - é Geology : Foote’s oben : - : ° Phyllites, slates, and lithomarges F 5 é Ferruginous quartzites . - - : 3 Basic igneous rocks : . Granites and gneisses. ° - Relations of granites and gneisses to the Diwan Lateritic rocks and hematitic breccias : . The manganese-ore deposits. : > : List of deposits . - 5 - : 5 Place names . : : - : : : Deposits visited . 2 5 . - Situation of the deposits . “ A Outcrops lateritoid and lichen- covered ; Prominence of the outcrops of manganese- and iron-ore - ° * Manganese-ore deposits apparently Bede but really surface replacements . : ‘ ‘ Evidence supporting the superficial replacement theory ° . The N scacaaderaukeie? Ghat sections Ramandrug Main Bed sections . - The Ramandrug lithomarges . - - Summary of origin . . 2 5 ° Depths to which the deposits extend. Possibility of original beds or lenses of mangan- ese-ore ° ° : . Width of the sence Length of the deposits . - 2 xlil MANGANESE DEPOSITS OF INDIA. PacE. CHaeTER XXXVIII.—concluded. Quantities of ore . a : > - 1014 Are the quantities of ore too large to have been formed by superficial replacement - ey LOL The manganese minerals present : - 1016 Psilomelane and wad formed by replacement of phyllite . - 2 : . . 1016 Pseudo-manganite and bgetitisi te in cavities ee (U7) Botryoidal and lead-like psilomelane : = LOL Braunite ? and hollandite? . . : . 1018 Chemical composition of the ores . = . 1018 Descriptions of depcsits - : : . 1020 Group I—The Ramandrug Deposits . : . 1020 1. Sannasil Haruvu (Ramanirug No. 2) . 1021 3. Ramandrug No. 4 . ; : - 1022 4. Ramandrug Main Bed . : . 1024 6. Ramandrug Barracks or Mixigancee Cave 1025 Group 11.—he Kannevihalli eae . - 1026 The Narihalla . - - . - 1026 Group II!.—The Cee Deposits . - 1027 Group 1V.—The Kamataru Deposits ° . 1027 45. Yelakala Banda . 3 2 a - 1029 47. Badapatti Banda : 2 c - 1029 52. Alada-Marada Banda . 2 - 1029 53. Durgamma Kolla 3 : “ - 1030 55. Pillal-marada Gundu . 4 A . 1031 56. Karada Badasdla Katevi . ; ». sLO8t 63. Hunase-marada Katevi ‘ ‘i - dsl CuapTeR XXXIX.—The Madras Presidency.—continucd. Chengalput District : : : : ; - 1032 Coimbatore District : : 2 ; - - 1032 Ganjam District . ; : : - 1032 1. Boirani . : - - - 1034 Manganese- laterite : 5 . . . 1036 2. Gudhidri , - = - 1036 3. Nautan-Barampur PF ‘ - 1036 4, Mathura . : : “ - 1037 5. Kaélikot . : - : . A 1037 6. Rambha . F : - 1037 Kadapah District . ° . . . ° « 1038 CONTENTS. xlii PaGE. CuaPreR XXXIX.—concluded. Karnul! District . - - ‘ A - 1038 Madura District . - = : < - 1039 Nilgiri Hills . 3 : H 5 ; : - 1039 Nellore District . 5 - 4 . : - 1040 Pudukottai State . i ; 5 2 - 1041 CHAPTER XL.— Madras Presidency—Vizagapatam District. History é ° A : - - 1042 Output and as : - ° : - 1045 Physical characters of the poo ees : : : - 1045 Geology . : : : : : : - 1046 List of deposits. 3 . : - 1047 The nature and quality of fhe. ores , : : . 1048 Communications and transport . ; : - 1050 The Kodur Mines . - < - : < - 1050 Output s : : - : : = - 1054 1. Garividi . : : - - : » 1055 2. Kodur. . 7 : : - : : 2 1059 The lithomarges, . A “ : 5 . 1080 Yellow ochre . z A - : : - 1061 Wad . Saat 4G : : ; > - 1061 Quartz-felspar-rock. : : A as . 1062 Felspar-rock . . : : ~ = - 1062 Vein-quartz /rose) . . : > - 1062 Pyroxene-spandite-felspar- eae 5 - - 1062 Spandite-rock and apatite-spandite-rock —- - 1063 Mangan-fluor-apatite : : ° : - 1063 Pyroxene-rock . . ; : : - L063 Pyroxene-spandite-rock . : : : . 1064 A fissure rock : . - - 1054 Apatite-felspar-spandite-rock iatetic) - - 1064 Xenoliths of crystalline limestone . é - 1065 Chert . : 5 - : ° . - 1065 Mangan-magnetite . 5 B “ z . 1066 The ore-bodies ° ° : : : . 1066 Nature and quality of the ores. ° : - 1068 The working of the deposit . : : LOT 3. Duvvam . 5 . 5 . . - 1078 4. Devada . : 5 é : - : - 1078 Apatite . 3 é c “ - - - 1073 Xliv MANGANESE DEPOSITS OF INDIA. CHAPTER X L.—continued. 5. Sandanandapuram Amethystine quartz . Chert : Lithomarges . > Scapolitic gneisses . 6. Sivaram . 4 7. Perapi . ° ° Shan dite-talepeu! works Replaced microcline-rock : Spandite-pyroxene-rock (rhodonite) . Chert and flint : ° ° : Scapolitic gneisses . : . 8. Itakerlapilli 9. Mulagam . 10. Govindapuram . 11. Garbham : Localities of apaiitie® howe cosh . Sections across the deposit Pegmatite and quartz crystals . Chert . : The Palapguddi Sone - 12. Kotakarra . . . ; Kotakarra I ° . Kotakarra II 2 ‘ : Opalized kodurite . : . - Pyroxene-scapolite-quartz-rock 13. Gadasam . : ° . 14. Avagudem : . 15. Aitemvalsa : : 16. Gotnandi : : . . 17. Bondapilli é : : . 18. Garraraju Chipurupalli (Garuja) . ly. Perumali ° ° : ° . 20. Ramabhadrapuram . . . Origin of the ores . 5 Nature and quality of the ores Boring operations 20 a. Sonpuram (West wend The quartzites é . Psilomelane concretions in Hithomangie rock Banded pyroxene- quartzite CONTENTS. CHAPTER XL.—concluded. 20 b, Mamidipilli (Middle Mound) Kodurite - - : : . . Biotite-kodurite . : : A Apatite-quartz-microcline-rock. 20 c. Bankuruvalsa (East Mound) . ° - Quartzites containing apatite, garnet, and crenhite 21. Taduru : 5 - 7 - - : Manganese-pyroxenites . . ° Graphite-apatite-spandite-rhodonite- aan: Sac Apatite-garnet-graphite-rock with manganese-ore Calcareous gneisses : = : - : Biotite- and garnet-pyroxene-gneisses - 22. Chintelavalsa : 5 : : c Scapolitic or calcareous gneisses 2 Biotite-gaeiss : : , 3 - Graphite-bearing manganese-silicate-rock . Other localities. . : - - , 3 Sandapuram . : : - - - Kantikapilli . - - : : 4 A CuapTeR XLI.—Maldive Islands and Mysore. Maldive Islands . - ; 3 - “ é Mysore < ° ° . . ° . - History . 5 : : . ° Mode of cccurrence and origin . - . Quality = 4 : - 2 Exports - - Bangalore District . - - ° Chitaldrug District . 2 . : zi 3 1, Sadarhalli . 4 ° . Interesting forms of lateritoid Manganiferous ochre . 2. Dod Kittadhalli : ‘ A 3. Madadkere 3 5 * : 4. Nirgudda Hills . " “ 5 5. Iplara Hills : g A - , 6. Bodimarsdi - : 5 F F Hassan District E E - ; : Kadur District F 3 ; = 5 Ubrani . Kannikalmatti (Hédikere) CHAPTER XLI.—concluded. MANGANESE DEPOSITS OF INDIA. Shimoga District . c History . 5 . Output ° ° e . Physical character of the botntay Geology and origin . Nature of the ores . Quality of the ores ‘ Communications and transport . List of deposits I. The Shikarpur Group II. The Ayanur Group 6. Tuppur 7, Short’s Block 8. Kumsi . Quantity of ore 9. Bikonhalli 10, Aladhalli . III. The Shankargudda Group . 11. Shankargudda ° 12. Tirandur . IV. The Channagiri Group 13. Sulekere 14. Gaddikalmatti 15. BuddamattiPeak . 16. Hoshalli 17. Treasury Hill V. The Shiddarhalli Group 18. and 19, Bhadigund and Ghee 20. Kanjiganagutti (Shiddarhalli Deposit) . 21. Urumanjanmatti . 22. Ragikalvadikinakeri Bhaui Nagase gutti Tumkur District 3. Sondenhalli (Solid Hill Mine) 4. Muskondli (Rowe’s Mine) 5. Karekurchi (Camp Mine) 6. Hattyal (Temple Hill Mine) . 7. Harenhalli (Government Road Mine) CONTENTS. CHarpteR XLIJ—North-West Frontier Province, Punjab, Rajputana, and the United Provinces, North-West Frontier Province. Kohat District Punjab - ‘ Jhang District Kangra District Lahore District Patiala State Rajputana . Ajmere Alwar State . Banswara State Bundi State . Jodhpur State United Provinces 5 Mirzapur District . . APPENDIX I. Bibliography of Indian Manganese. APPENDIX II. Geographical Index. INDEX. wD ee we. + 8%, LIST OF PLATES. PART I. PLATE 1.—Photomicrograph by reflected light of a polished and etched slice of manganese-ore from Ramdongri, Nagpur district, Central Provinces. x16. PLATE 2.—Mass of braunite crystals from Lohdongri, Nagpur district, C-n- tral Provinces. 4 natural size. PLATE 3.—Pyrolusite from Pali, Nagpur district, Central Provinces. 4 natural size. PLATE 4.—Dendrites of manganese oxide on Upper Vindhyan Sandstone, Panna, Central India. +4 natura) size. PLATE 5.—Fig. 1.—Stalactitic psilomelane from Garbham, Vizagapatam district, Madras. 4 natural size. Fig. 2.—Reniform psilomelane from Garbham, Vizagapatam district, Madras. 4 natural size. PLATE 6.—Fig. 1.—Psilomelane showing conchoidal fracture, Tekrasai, Singhbhum district, Bengal (J. 917). Natural size. Fig. 2.—Mammillated psilomelane from Guguldoho, Nagpur dis- trict, Central Provinces. } natural size. PLATE 7.--Spessartite crystals (trapezohedral) with interstitial quartz, on a basis of manganese-ore. From Waregaon, Nagpur districte Natural size. PART II. PLATE 8.—Photomicrographs :— Fig. 1.—Opalized kodurite. Kodur, Vizagapatam district. x 16. Fig. 2.—Opalized kodurite with some orthoclase remaining. Boirani, Ganjam district, Madras. x 16. Fig. 3.—Apatite-spandite-rock. Kodur, x 16. Fig. 4.—Spandite (manganese-garnet), in psilomelane. Rama. bhadrapuram, Vizagapatam district. x 23. PLATE 9.—Banded hematite-quartzite; from Khatola, Jabalpur district, Central Provinces. The jaspery quartzite bands appear white in the photo, but are really pinkish. Natural size. PLATE 10.—Photomicro*raphs :— Fig. 1.—Fine-grained quartzite being replaced by manganese-ore. Sivarajpur, Panch Mahals district, Bombay. x 23. MANGANESE DEPOSITS OF INDIA. Fig. 2.—Piedmontite-gneiss. Pali, Nagpur district, Central Pro- vinces. X 23. Fig. 3.—Piedmontite and _ felspar, latter altering to calcite, Ghogara, Nagpur district, Central Provinces. x 23. Fig. 4.—Piedmontite in crystalline limestone. Ghogara. x 23. PLATE 113.—- Photomicrographs :— Fig. 1.—Very fine-grained gondite. Jothvad, Narukot State, Bombay. x 23. Fig. 2.—Typical gondite. Wagora, Chhindwara district, Centra] Provinces. X 23. Fig. 3.—Strained gondite by ordinary light. Ramdongri, Nagpur district, Central Provinces. x 23. Fig. 4.—Same as fig. 3, but with nicols crossed. PLATE 12.—Photomicrographs :— Fig. 1.—Gondite, with garnets altering. Ukua, Balaghat district, Central Provinces. x 33. Fig. 2.—Spessartite-rock, partially converted into manganese-ore. Mansar, Nagpur district, Central Provinces. x 23. Fig. 3.—Rhodonite-rock. Ramdongri, Nagpur district, Central Provinces. x 23. Fig. 4.—Pyroxene (Rhodonite ?) altering to manganese-ore. Kodur, Vizagapatam district, Madras. x 23. PLATE 13.—Photomicrographs :— Fig. 1.—Black manganiferous quartzite. Balaghat mine, Balaghat district, Central Provinces. x 60. Fig. 2.—Black manganiferous quartzite. Manegaon, Nagpur district, Central Provinces. x 16. Fig. 3.—Vein-quartz being replaced by psilomelane. Chik Vadvati, Dharwar district, Bombay. x 23. Fig. 4.—Quartz-felspar-rock being replaced by manganese-ore, Garbh4m, Vizagapatam district, Madras. x 23. PLATE 14.—Piedmontite and manganese-ore nodules in a piedmontite-lime- stone. Around the manganese-ore nodule is a thin rim of piedmontite. 4 natural size. PLATE 15.—Pyrolusite (dark) and calcareous tufa (light); from Pan Kuan, Dhar Forest, Central India. 4 natural size. PLATE 16.—Map of the chief occurrences of manganese-ore in India. Scale 1 inch=256 miles. PART IV. PLATE 17.—Fig. 1.—Inclusions of manganese-ore and manganese-silicate-rocks in porphyritic biotite-granite. Jothvad, near Jambughoda, Narukot State, Bombay. February 1905, LIST OF PLATES. hi Fig. 2.—Outcrop of manganese-ore on a quartzite ridge. Near Sivaréjpur, Panch Mahals, Bombay. February 1905. PLATE 18.—Fig. 1.—Intense folding in manganese-ore and sandy slates. Kajlidongri, Jhabua State, Central India. January 1905. Fig. 2.—Quarrying manganese-ore at Kajlidongri. February 1905. PLATE 19.—Sections of the rmanganese-ore deposit at Kajlidongri, Jhabua State. Seen in surface cross-cuts. For positions of these cross-cuts see sketch-plan, PLATE 20.—Crumpled manganese-ore ‘beds’ at the Balaghat quarry. Balaghat district, Central Provinces. March 1904. PLATE 21.—Plan of Balaghét Manganese Mine. August 1906. Scale 5 chains ==" Vinch. PLATE 22.—Hillock composed entirely of manganese-ore. Sitapar, Chhindwara district, Certral Provinces. December 1903. PLATE 23.—Manganese-quarry at Kodegaon, Nagpur district, Central Provinces. November 1903. PLATE 24.—Geological sketch-map of Group I of the manganese deposits of the Nagpur district. Scale 1 inch =2,000 feet. PLATE 25.—Sketch-map of Gumgaon manganese-ore deposit, Nagpur district Scale 12 inches=1 mile. PLATE 26.—Fig. 1.—Kandri Hill from the east. Fig. 2.—Level 3 of Kandri manganese-quarry. PLATE 27.—Sections across the Kandri manganese-ore deposit along lines of section in Plate 32. PLATE 28.—General view of the manganese-quarry at Kandri, Nagpur district, Central Provinces. January 1904. PLATE 29.—Kandri manganese-quarry, general view. January 1904. PLATE 30.— Working face at level 2 of the Kandri quarry. January 1904, PLATE 31.—Excavations in the ‘ boulder’ or ‘talus’-ore deposit at Kandri. January 1904. PLATE 32.—Sketch-plan of the Kandri manganese-ore deposit, Nagpur district, Central Provinces. Scale 1 inch =80 yards. PLATE 33.—Manganese-ore deposit. Mansar, Nagpur district, Central Provinces. January 1904. PLATE 34.—Fig. 1.—The west end of the Mansar deposit. January 1904. Fig. 2.—View showing the structure of a portion of the Mansar ore-deposit. January 1904, PLATE 35.—Sketch-plan of the Mansar-Chargaon ore-band. Scale 1 inch = 720 feet. PLATE 36.—Fig. 1.—Sampling manganese-ore at Mansar. Fig. 2.—Outcrop of manganese-ore. Sdtak, Nagpur district, Central Provinces. February 1904, li MANGANESE DEPOSITS OF INDIA. PLATE 37.—Sketch-plan of the manganese-ore quarry at Beldongri, Nagpur district. February 1904. Scale 1 inch =200 feet. PLATE 38.—Manganese-deposit at Lohdongri, Nagpur district, Central Provinces. February 1904. PLATE 39.—Fig. 1.—Folding in the Lohdongri manganese-deposit. February 1904. Fig. 2. —Lohdongri manganese-deposit with ore-stacks in the fore- ground. February 1904. PLATE 40.—Fig. 1._Sketch-plan of the Gowdri Warhona manganese-ore deposit, ChhindwAra district. Scale 1 inch=440 feet. Fig. 2.—Plan showing the extremely variable strikes and dips of the two ore-bands at Mandri, Nagpur district. Scale 1 inch = 100 yards. Fig. 3.—Section across the Lohdongri manganese-ore deposit, Nagpur district. PLATE 41.—Fig. 1.—Manganese-quarry at Kacharwahi, Nagpur district, Central! Provinces. February 1904. Fig. 2.—Manganese-ore stacked at Prince’s Dock, Bombay, ready for shipping. PLATE 42.—Excavation for pyrolusite in crystalline limestone at Pali, Nagpur district, Central Provinces. January 1904. PLATE 43.—Geological sketch-map showing the manganese-ore deposits of the Nagpur-Balaghat area, Central Provinces. Scalel inch=4 miles. PLATE 44.—General view of the workings at Ramandrug Main Bed, Sandur Hills. September 1907. PLATE 45.—Manganese-ore body with lithomarge below; Ramandrug Main Bed, Sandur Hills. September 1907. PLATE 46.—Cliff of manganese-ore at Durgamma Kolla, Sandur Hills. Septem- ber 1907. PLATE 47.—General view of the manganese-quarry at Kodur, Vizagapatam district, Madras. From *. N. E. January 1905. PLATE 48.—Section at Kodur showfng lithomarge, wad and manganese-ore. January 1905. PLATE 49.—The east end of the Kodur quarry. January 1905. PLATE 50.—Fig. 1.- North-east corner of Kodur manganese-quarry. December 1904. Fig. 2.—Unloading manganese-ore at Garividi Railway Station, East Coast Railway. January 1905. PLATE 51.—‘ Country ’ of wad and lithomarge at Garbham. December 1904. PLATE 52.—Manganese-quarry at Garbhim, Vizagapatam district, Madras. From the 8S. 15° E. December 1904. PLATE 53.—Garbham manganese-quarry from W. 40° N. Dece ner 1904, PLATE 54.—Fig. 1.---Manganese-ore in sifu at Garbhaim. December 1904. LIST OF PLATES. lui Fig. 2.—Manganese-ore (black) forming by replacement of quartz- felspar-rock (white) at Garbham. December 1904. PLATE 55.—Geological sketch map and section of the rocks near Tadurv. Scale 1 inch=about } mile. PLATE 56.—Map of a portion of the Vizagapatam district, Madras Presidency, showing the manganese-ore localities. Scale 1inch=4 miles. PLATE 57.—Manganese-ore deposit at Kumsi, Shimoga district, Mysore. Sep- tember 1907. r . c% AR. in EDS +e a 3, eee a r . - ~~ ae LIST OF FIGURES IN THE TEXT. PART I. Fre. 1.—Braunite, Kajlidongri Fic.2.— Do. do, : : : : : Fie.3— Do., Kacharwabi ; : : - 2 Fie.4— Do., do. : : aay ©. : : - Fie.5.— Do, ° do. : A : 2 ‘ a : Fic. 6.—Braunite twin, Kachatwéhi* 2 : - - 2 s Fic. 7.— Ditto ditto . : : - - = . Fra. 8.— Ditto ditto . : : > = = x Fic. 9.—Braunite, Kacharwahi : - : - - - Fie. 10.— Do., Lohdongri . : ° > : A 5 : Fie. 11.—Blanfordite . : ‘ : : oy es : : Fre. 12.— Do. © > . : ° Fic. 13.—Spessartite, Papesatoavon, ‘Bichua aa Wakeeeon - - Fie. 14.— Do., striated trapezohedron, Chargaon Fic. 15.— Do., trapezohedron and dodecahedron, Waregion Fig. 16— Do., * dodecahedron, Kulu and Kachi Dhana Fie. 17-— _Do., trapezohedron and hexoctahedron, Bhui Hurki : and Waregdon Fie. 18:-— Do., trapezohedron, dodecahedron, iS Bettas. Waregaon Fie. 19.— Do., ° trapezohedron, composed of vicinal hetoctshedral faces, Waregaon : - : Fre. 20.— Do., octahedron. - : ° e - PART II. Fic. 21.—Ideal section across a 8yncline of manganiferous rock . Fic. 22.—Typical section of laterite. Talevadi, Belgaum district . - PART III. . 23.—Diagram showing the variation in the prices of manganese- ore at United Kingdom ports since 1890 24,—Diagram showing the variation in the prices of. manganese- . ore at United Kingdom ports since December 1904 . - , 25.—Diagram showing the annual manganese-ore production of the different districts of the Central Provinces = - PAGE. 58 419 lyi MANGANESE DEPOSITs OF INDIA. Fie. 26.—Diagram showing the annual manganese-ore production of the different provinces of India since 1892. . - Fic, 27.—Diagram showing the manganese-ore production since 1890 of the four leading countries = < “ c . Fic. 28.—Prospecting an outcrop on low ground < . Fic. 29.— Ditto ditto along a ridge : ° Fic. 30.—Quarrying a thick ore-band of mederate dip in a hill A Fic, 31.—Mining or quarrying a thick ore-band of steep dip in a hill Fic. 32.—Quarrying a thick ore-band cropping out of low ground Fic. 33.—A thin ore-band cropping out of low ground : : Fie. 34.—Scattered ore-bodies in lithomarge . . : < Fie. 35.—A lateritoid capping ; : - ‘ 5 A Fia. 36.—A detrital or talus-ore eposit . c 5 . Fig. 37.—Systematic plan of working detrital deposits : C . PART IV: Fia. 38.—Map of the Sivarajpur manganese area < . Fie. 39.—Quartzite partly replaced by manganese-ore 5 5 - Fia. 40.—Map of the Thirori manganese-ore bands. Scale 1 inch = 1 mile . - : 5 . . 5 Fie. 41.—Plan and section of a penis of the Reon Jim manganese-ore deposit . 2 6 * c 6 . < Fie, 42.—Map of the Balaghat manganese-ore deposit. Sie Linch = 1 mile - = > . ° . c ° Fie. 43.—Round nodules of red quartzite in manganese-ore ; at BaléghAt Fic. 44.—Section across the Hirapur portion of the Balaghat manganese - ore deposit c . ° ° ° . . . Fria. 45.—Sketch-plan of the Miragpur manganese-ore occurrences . c Fie. 46.—Section across the Garkar-Bhtinga portion of the Asalpani manganese-ore de posit . . . Fic. 47.—Sketch-plan of the Gaimukh and tathonwen aanosite - Fra. 48.—Banded hematite-jasper showing slaty cleavage . - Fic. 49.—Sketch-plan of Kodegaon Mine 1 3 4 : . Fia.50.— Ditto ditto Mine 2 : c 5 : . Fria, 51.—Diagram of the S, E. end of the Kandri manganese-ore body . Fia, 52.—Diagrammatic section across South Hill, Kandri, at Level 2 Fra, 53.—Anticlinal overturn of back of ore-body near level 3, Kandri . Fra, 54,— Diagram illustrating the faulting of East Hill, Kandri . Fia. 55.— Do. to illustrate shape of K4ndri manganese-ore body . Fic, 56.—Section in detrital deposits at Kandri . ° ° . Fie, 57.— Ditto ditto : é fe : C Fie, 58,—Sketch-section across the Mansar deposit at its highest point . PAGE. 444 452 551 552 555 557 559 560 561 563 564 565 653 658 699 707 715 716 720 746 764 782 808 846 848 863 863 863 865 866 877 878 881 LIST OF FIGURES IN THE TEXT. Fria. 59.—Overturn in beds of manganese-ore at Mansar ° : i Fie. 60.—Section across the Kamthi Lady Pit, Chargion . : : Fie. 61.— Ditto one of the Satara Pits, ChArg4on Fie. 62.—Lenticularly expanding and contracting band of Soudite? Mansar.. : - c Fic. 68.—The course of two ‘ore-beds’ at C (see plan of Hphdoneni) Fic. 69.—Sketch-plan of ore-bands and hills at Mandri : : 2 Fia. 70.—Slickensides-grooving in quartzites at M4ndri : 5 : Fic. 71.—Map showing the position of the Mandri, Panchéla, M4negion, Guguldoho, and Bhandarbori manganese-ore deposits. Scale linch = 2 miles = : ‘ - 5 3 Fig. 72.—Plan showing local twisting of orice of ore-band at Mgneg4on Fic. 73.—Sketch-plan of the Mohugaon manganese-ore deposit . Fic. 74.—Section showing manganese impregnations in limestone . Fie. 75.—Diagrammatic sketches of some manganese-ore nodules . Fic. 76.—Section across the R4mandrug Main bed deposit . Fig. 77.—Piece of altered magnetite-slate . y Fic. 78.—Rough cross-section of Ramandrug No, 4 depoatt : . - Fic. 79.—Geological sketch-map of the Kodur Mines, Vizagapatam district . 2 ° : : 3 Fras. 80 anp 8].—Alternative siteterotations of simnouere iene the line of section XY in fig. 79 a . x Fig. 82.—Rough sketch-plan of the Kodur Quarry aaa 1905) Fie. 83.—Section seen in a pit at Perapi . 5 4 : i Fic. 84.Sketch-plan of Garbh4m . : . - 2 , Fic. 85.—Quartz-felspar-rock undergoing replacement by manganese oxide . c : z é Fie. 86.—Felspar-rock qidercong replacement he manganese-ore noe ochre . < . ° ° c Fria. 87.-—Section across the middle of the Gasbinen denoae z : Fig. 88.— Ditto the Garbhgm deposit to east of middle. i Fie. 89.—Diagram of anticlinal fold (A) affecting the Garbh4m deposit west of middle . S : : E : “ Fria. 90.—Section seen in the east end of ig Garbham quarry . Fie. 91.— Do. across one of the Sonpuram pits. E A ¥ Fia. 92.— Do. across hill near Chintelavalsa . ° . ° c LIST OF TABLES. PART I: TaBLe 1. Physical constants of the manganese-iron group Of elements TABLE 2. List of known manganese minerals with their chief properties TaBLeE 3. List of Indian manganese minerals é : Taste 4. List of certain minerals associated with the Indian manganese- ore deposits TaBLE 5. Faces observed on Indian pronnites TABLE 6. Ditto foreign braunites TABLE 7. Analyses of Indian braunites TABLE 8. Ditto pyrolusites . : TABLE 9. Comparison of properties of manganite, pseudo- Peniiganite, aa pyrolusite . : . . . : 7 Tas 10. Analyses of hollandite : : Taswy 11. Ditto in terms of manganates TaBur 12. .Do. of Indian psilomelanes F ‘ : TABLE 13. Ditto ditto in terms of manganates Taste 14, Do. (in terms of manganates) of psilomelane obtained by calculation ; Taste 15. Analyses of psilomelane obtamed by algalation - 5 TABLE 16. Properties of the yellow and brown pyroxenes associated with the gondite series : TABLE 17. Analyses of Indian manganese-garnets TaBLE 18. Optical properties of pink micas 5 3 TasBLE 19. A-key to the identification of the black, ad dank gy, iron, manganese, and chromium minerals Tas_E 20. A-key to the identification of the black, dark. -grey, ad bronze-coloured, manganese-ores . PART II. TaBLE 21. Classification of Indian occurrences of manganesé-ore aiid manganese minerals according to their geological position TABLE 22. Classification, according io origin, of the manganese-ores asso- ciated with the Dharwar rocks : 5 . , : TABLE 43. Classification of the deposits of lateritic manganese-ores TABLE 24. Analyses of lateritic ores . : . - c c PART III. Tas ie 25. List of vernacular names for manganese-ore é ° TABLE 26, Prics of manganese-ore per long ton in 1886 100 101 112 114 136 168 198 226 228 240 305 385 389 412 414 Ix MANGANESE DEPOSITS OF INDIA. TABLE 27. Variation in the price of manganese-ore c.7.f. at United Kingdom ports . : : . . . TABLE 28. Detailed production of the Vicapapntast district TABLE 29. Production of the Madras Manganese anon (vicawarties! district) during 1906 : : TaBLE 30. Detailed production of the Balaghat disteiag : 3 TABLE 31. Ditto Bhandara do. 5 3 F TABLE 32. Ditto Chhindwara_ do. 5 ; - TABLE 33. Ditto Nagpur do. : B = TABLE 34. Ditto remaining provinces . . Tapie 35. Annual production of manganese-ore in India, by dias states, and provinces . ° = - . . Tape 36. Production of manganese-ore as iver in the ‘ Mineral Produc- tion of India’ . = ; - : TasiE 37. Total production of each district, states and province . : TABLE 38. List of Indian deposits from which over 160,000 tons of manganese-ore have been extracted up to the end of 19U6 TABLE 39. World’s production of manganese-ores from 1890 to 1906. Tape 40. World’s production of manganiferous iron-ores from 1890 to 1906 A A : A . 0 E TapLE 41. World’s total production . “of manganese-ores and manganifer- ous iron-ores from 1890 to 1906 TasLeE 42. Exports of Indian manganese-ore from 1892 é 3lst re 1907. ; - 5 A : A : TaBLeE 43. Distribution of exported inden manganese-ore for the years 1895-1896 to 1906-1907 ‘ c 4 c Tape 43A, Detailed production of manganese-ore in India i in 1907 S TABLE 44, Rates for coolic labour . : : 3 e 4 5 TaBie 45. Daily number of workers employed on the manganese quar- ries from 1895 to 1907 : ; ‘ 5 B ; TaBLE 46. Daily number of workers employed in the manganese quar- ries of Bombay and the Central Provinces, from 1900 to 1907 . C : : . ; ° ° ° . TaBLE 47, Rates per ton for carting manganese-ore . . ° TABLE 48, Rates for the carriage of manganese-ore to the ‘iS over Indian railways . C e : = : : TapLe 49. Rates for the carriage of eames -ore to Mormugao by the Southern Mahratta Railway . 5 5 ‘ - TABLE 50, Summary of costs per ton of delivering Indian manganese- ore c, 1. f. at English and Continental ports . . . Tase 51, Average cost of Indian manganese-ore delivered c, 2. f, at English and Continental ports ° ° ° . . Pace. 415 434 435 436 437 438 439 442 443 445 446 447 450 453 454 455 456 459 468 470 471 476 479 480 486 487 “TABLE 52, Tas e 53, TABLE 54. TABLE 55. TABLE 56. TABLE 57. TABLE 58. TABLE 59. TABLE 60. TABLE 61. TaBiE 62, TABLE 63. TABLE 64, Taste 65. TABLE 66, TABLE 67. TABLE 68, TABLE 69, TABLE 70. TABLE 7]. LIST OF TABLES. Comparison of cost of delivering Brazilian, Russian, and Indian manganese-ore ¢, 7. f. in Londen . - ° Royalty, in annas per ton, levied in certain Native States and. Zemindari Lands : : . A Royalties in annas per ton jovi on Central Bi vinbod manganese-ore at 25% on pit’s mouth value : Analyses of manganese-ores and manganiferous iron-ores from Singhbhura, district, Bengal : : , - Analyses cf manganese-ores from Panch Mahals, Bombay . Ditto Satara district, Bombay Ditto Jhabua State, Central India . 2 5 Ditto Balaghat district, Central Provinces . 9 Ditto Bhandara district, Central Provinces . c . Ditto Chhindwara district, Cen- tral Provinces 0 5 Analyses of samples of manganese-ores from the Nagpur district, Central Provinces . é ; 5 Analyses of hand-specimens of manganese-ores from the Nag- pur district, Central Provinces t ; Analyses of manganese-ores, manganiferous iron-ores, and, iron-ores, from the Jabalpur district, Central Provinces. Analyses of samples of manganese-ores and ferruginous manganese-ores from the Vizagapatam district, Madras . Analyses of hand-specimens of manganese-ores (some ferru- ginous) from the Vizagapatam district, Madras . Average analyses of the manganese-ores of the Vizagapatam district, as supplied by the Vizianagram Mining Company . c : : Average analyses of the ferruginous mangavese-ores of the Vizagapatam district, as supplied by the Vizianagram Mining Company Range of analyses of manganese-ores and manganiferous iron- ores from the different districts and provinces of India Mean of analyses of manganese-ores and manganiferous iron- ores from the various districts and provinces of India Analyses of Indian manganese-ores for which buyers stipu- late when making contracts . - 4 509 509 510 512 Ixti TABLE 72, TABLE 80, TABLE 81, TABLE &2., TABLE 8&3, TABLE 84, TABLE 85. TABLE 86. TABLE 87. TABLE 88. TABLE 89. TABLE 90. TABLE 91. TARLE 92. . Mean of ditto . , . Limits of ana'yses of Indian ores in Tab le 72 arranged secon MANGANESE DEPOSITS OF INDIA. Liwits of analyses of cargoes of manganese- and mangani- ferous iron-ores landed at Middlesborough during the 16 years 1897 to 1906 . 5 . ‘ : = ) . ing to probable source. - . : : - . . Mean of ditto . - : Table 73, : Analyses of the manganese-ores of the world - - 77. Value of the Indian manganrse-ore production as cepa in the Statistics of Mineral Production 78. Export values of the mangan-se-ore protuced in the Medien Presideney from 1892 to 1906 - 79, Export vaiues of the manganese-ores produced in the C aattel Provinces from 1900 to 1906 - Export values of the mangane é ‘ 2 2 a 210 601 Kandri 3 : ‘ i ; : ° 175,726 Mansar ; 5 : . : s 5 154,358 Lohdongri ; < 2 . 5 : 147,787 KaAjlidongri ¢ c F 6 ; . 134,431 Kumsi F : F ; " . 113,667 Chikhla I . : . : . . . 100,477 SYNOPSIS OF PART III. xclil After comparing the Indian output figures with the variations in price, tables are given showing the output of manganese-ore and man- ganiferous iron-ore by the various countries of the world since 1890. Tables showing the yearly exports of Indian manganese-ore and the distribution of itwhen exported are also given. , [CHAPTER XXIII] Labour and Costs of Production. The daily number of workers employed in the Indian manganese quarries has risen from about 1,000 in 1895 to about 14,000 in 1906, and probably about 20,000 in 1907. The various items in the cost of putting Indian manganese-ore on the markets in Europe and America are considered, and the following figures are deduced as representing the average cost per ton of delivering ore from the various producing provinces ¢. 7. f. at English and Con- tinental ports :— Average Cost of Indian Manganese-ore delivered c. i. f. at English and Continental Ports. Area from which derived. Sea ce ene coe Rs. a. Central Provinces : ‘ . : . | Bombay . -| 26 14 Ditto : - . . ° . |Caleutta . i ola G Jhabua, Central India. : 5 : . |Bombay . qi PF al Vizagapatam, Madras_. 5 : : . | Vizagapatam .| 23 7 Sandur, Madras a A A : . | Mormugao 5 |) BR yi Mysore - ° . . ° 5 . | Mormugao | 29 8 XCiV MANGANESE DEPOSITS OF INDIA, [CHAPTER XXIV.] Valuation and Chemical Composition of Manganese-ores. Ores of manganese and iron are usually classified for commercial purposes into three groups :—manganese-ores, manganiferous iron-ores, and iron-ores. The second term is considered to be too loosely applied ; it is used to include ores containing a much larger percentage of man- ganese than of iron, 7¢., for ores that would be more accurately designated ferruginous manganese-ores. For classifying ores containing an amount of Mn+ Fe equal to 50% or over the following figures are put forward :— RR RR Mn per cent. Fe per cent. Manganese-ores . . - ° r - 40—63 0—10 Ferruginous manganese-ores . . : -| 25—50 10—30 Manganiferous iron-ores : “ : - 5—30 30—65 Iron-ores c . : . : : : O—5 45—70 Analytical figures are then given of samples and hand-specimens of Indian ores from the various districts and States, and also of the cargoes as received at Middlesborough ; and for comparison a table is given of analyses of manganese-ores from all parts of the world. Reference is also made to the following of the rarer constituents of Indian manganese-ores :—Al], Ba, Ca, Mg, K, Na, As, S, Co, Ni, Cu, Pb, Zn, Ti, combined water, and COg. [CHAPTER XXV.] Value of the Indian Manganese-ore Production. By making use of the figures of cost of production given in the previous chapter and the current market values of the Indian ore according to its analysis, detailed figures of the /. 0. b. or export value SYNOPSIS OF PART IItI. XCV of the ore produced in each area are worked out. They are summarized in the following table : — Export Values in Sterling, f. 0. b. at Indian Ports, of the Manganese-ore produced in the various Provinces of India from 1892 to 1907. | Ba is- | af Ce | Year. pew Bengal. Bombay. Pie ieee Madras. | Mysore. Totals. £ £ £ £ £ i £ | £ £ 1392 1,050 ‘ai 1,050 1893 4,460 4,460 1894 11,220 11,220 1895 14,037 14,037 1896 66,821 66,821 1397 80,362 80,362 1898 | 55,895 55,895 1899 | es | we si8 «0 91,354 ae 91,354 1900 | os | ee | ale | wie 100,618 125,744 or 226,362 1901 : =F ae xe 133,407 | 82,527 ae 215,934 1902 | ae ye | A | te 93,923 | 57,093 as | 151,016 1903 ae ae 52 5,638 138,982 | 43,889 ae | 188,509 1904 | aa ae 9,588 91,047 | 37,298 ar 137,933 1905 ag st } 19 19,159 162,281 | 41,972 Se 223,431 1906 Se | 1,417 | 13,904 70,938 700,828 114,212 67,779 969,078 1907 20 5,010 46,880 61,061 | 1,193,774 | 238,300 203,420 | 1,748,465 Totals. 20 6,427 | 60,803 166,334 | 2,614,860 | 1,066,234 271,199 | 4,185,927 In comparing the value of the manganese-ore with that of other minerals produced in India it is usual to use the export value of the manganese-ore. According to this method manganese-ore was the sixth inorder of value for the years 1903 to 1905, and third in 1906 and 1907 But the true value on the world’s markets is the c. 7. 7. value of the, ore. Inserting this in the table of values and making a few corres- ponding alterations in the figures for other Indian minerals, manganese- ore is seen to stand fourth in order of value in 1906 and third in 1907. Most of the other Indian mineral products are not, however, valued in the raw condition, but in the condition in which they are fit for man’s use. If the manganese-ore be given the value the manganese has when converted into ferro-manganese, then manganese-ore shares the first place with coal as regards value. Since, however, the value to India is the export value of the ore, and not either itsc. 7. /., or ferro-manganese value, it is evident that the difference between ihe export value and the ferro-manganese value may be taken as a rough measure of the loss that India suffers by exporting its ore in the raw condition, instead of smelting it in the country. The following table shows the value o the Indian output of manganese-ore for the years 1905, 1906 and x¢cvi MANGANESE DEPOSITS OF INDIA. 1907, according to the three different methods of evaluating, and also the total value from the beginning of the industry to 1907 :— i Year. | ag yen c. i. f. value. Peau case | £ | ¢ £ Te et i ae) 923,431 | 454,364 2,096,952 TIGO6?. 6.2 phew tinea 969,079 1,502,471 4,971,998 W075 7.62 AE ae 1,748,465 2,564,115 | 5,024,982 1892-1907) as te 4 4,185,927 | 6,773,283 17,422,692 [ CHAPTERS XXVI AND XXVII.] The Mining and Quarrying of Manganese-ores. In the former of these chapters the way in which it would be hest to work the Indian manganese-ore deposits, taking into consideration their geological structure, is considered. In the second chapter a description is given of the methods actually in use in the Indian man- ganese quarries, and attention is drawn to the waste of valuable ore that takes place in some quarries with the present methods of work, And to show that in some countries it is thought worth while to em- ploy more elaborate methods in mining the ores, to win lower grade ores than are considered worth notice in India, and, it necessary, to subject the ore when won to some sort of mechanical concentration, a short account is given of methods in vogue in Brazil, Virginia, Panama, and other countries. [CHAPTER XXVIII.] The Uses of Manganese. An attempt is made in this chapter to bring together such facts as are available concerning the manufacture of spiegel-cisen and ferro- manganese, the literature of which is very scanty and scattered. It is SYNOPSIS OF PART III. xevil shown that the difference between the cost of the materials that would be required to manufacture ferro-manganese in India, and the price the alloy produced would fetch on the EKuropean and American markets is so large that it is improbable that the other items in the manufac- ture of this alloy besides the cost of materials—and concerning which no figures are available—would account for the whole of this difference ; and in fact that it is not improbable that considerable profit would attach to the manufacture of ferro-manganese in India, once a market for it had been obtained. Accounts are also given of the use of manganese-ore in India in native iron-smelting, in colouring glass and enamels, and for pottery, and of the use and valuation of peroxide ores as a source of oxygen. . 5 MEMOIRS OF THE GEOLOGICAL SURVEY OF INDIA. VOLUME XXXVII. Tue Mancanese-Ore Deposits or Inpia, by L. LetgoH FERMoR, A.R.S.M., B.Sc. (London), F.G.8., Assistant Superintendent, Geological Survey of India. PART I: INTRODUCTION AND MINERALOGY. (With Plates 1 to 7.) Published by order of the Government of India. CALCUTTA : SOLD AT THE OFFICE OF THE GEOLOGICAL SURVEY, 27, CHOWRINGHEE ROAD. LONDON : MESSRS. KEGAN PAUL, TRENCH, TRUBNER & CO. BERLIN : MESSRS, FRIEDLANDER UND SOHN. 1909. : £. ey elt 2 ae 7 A 3 : : = = We v wat is 7 —*. = = a : = Yo oT eet tant : ee thse 4 a a1) TAY 7! 2 ij BOP iti Se Fa : =} ASO thay = 46 cing Set ie pie sani “1, b fobs he. ies : y - « an 1% Ve y Ve bi << ; : Sh. i (eure hort ut : tal “ites is 2 Ps } r Pato - ate VARGO. 0) 4 ~hb) SUA AS KS + ; A - of i > ‘2 Pad ian a Al - = ay 2 7 -® THE MANGANESE-ORE DEPOSITS OF INDIA PART I INTRODUCTION AND MINERALOGY ABRIDGED CONTENTS OF PART I. CHAPTER. I.—Introduction . : : Il.—Mineralogy—General . ° 3 : Iil.—Oxides . : C ° ° ° IV.—Manganates and Carbonates : V.—Silicates—P yroxenes and Amphiboles VI.—Silicates—Garnets VII.—Silicates—Epidotes, Micas, ete. VIII.—Titano-silicates, Niobates, Phosphates, and Kishatntte 7 IX.—Associated Non-manganiferous Minerals : . ; X&X—Identification of Manganiferous Minerals. ; THE MANGANESE-ORE DEPOSITS OF INDIA PART I INTRODUCTION AND MINERALOGY CHAPTER I. ENTE ODUCTION. History of the investigation—Scope of this Memoir—Acknowledgments—Analy- tical work—The visitor to India—Literature of Indian manganese-ore deposits— Literature of foreign manganese-ore deposits. Nature of manganese—Origin of the word ‘manganese’—Recognition as a new element—Distribution in Nature—In the mineral kingdom—In the vegetable kingdom—In the animal kingdom. Although it has long been known that ores of manganese exist in Baer bi dliaunrceti: various widely separated parts of India, yet it gation. was not until 1891 that any serious attempt was made to work them. In that year a syndicate, which later was formed into the Vizianagram Mining Company, Limited, started work on the deposits of the Vizagapatam district, Madras, the first export of ore taking place in 1892; since then prospecting over various parts of India has led to the discovery of many other deposits, and to the opening up both of the newly discovered deposits and of those that were previously known and had been noticed in Ball’s Economic Geology. The production of manganese-ore in India has increased almost con- tinuously from year to year, so that this country has taken a higher and higher place amongst the manganese-producing countries of the world. In 1906, India probably reached the first place, whicn she is likely to retain for at least the present year. Before the beginning of the I B 2 4 MANGANESE DEPOSITS OF INDIA: INTRODUCTION. [ Parr I: industry the Geojogical Survey was in possession of nearly all the information—summarized in Ball’s Economic Geology and Mallet’s Mineralogy—that was available concerning the Indian manganese-ore deposits. But, as so often happens when a particular set of mineral deposits is first opened up, our knowledge of the deposits did not increase commensurately with the development of the industry ; and the geologi- cal evidence made available by the opening up of the manganese quarries was neglected. Consequently by the year 1903 there was a flourishing industry in our midst about which the Geological Survey knew very little ; and. in this same year I was deputed by Dr. Holland, Director of the Geological Survey, to investigate the manganese-ore deposits of India. During the previous field season (1902-03) I had, in company with Mr. E. Vredenburg, first come into contact with manganese-ore deposits in the field ; namely, in Indore State and the Dhar Forest in Central India, and in the Hoshangabad and Nimar districts in the Central Provinces. During the ensuing field seasons I visited the following manganese areas :— 1903-04.—Nagpur, Chhindwara, Bhandara, Balaghdét and Jabal- pur districts, Central Provinces. ; 1904-05.—Jabalpur district, Central Provinces; Ganjém and Viza- gapatam districts, Madras; Singhbhum district, Bengal ; Jhabua State, Central India; Panch Mahals and Satara districts and Narukot State, Bombay. In December, 1906, I was able to revisit the deposits of Kandri, Mansar, Satak, Beldongri, Lohdongri, Kacharwahi, Waregdon, Mandri, and Manegdon, in the Nagpur district, and bring my knowledge with regard to these deposits up to date. I was also able to examine two fresh deposits ; Panchala in Nagpur and Asalpani II (Karli) in Bhandara. During August and September, 1907, I made a brief examination of a few of the deposits in the Sandur State, Bellary district, Madras ; and during September, in the Chitaldrug, Kadur, Shimoga, and Tumkur districts, Mysore. In October and November, 1907, I found a few occurrences of manganese-ore in the Nilgiri Hills, and in the latter month paid a short visit to some of the deposits in the Portuguese territory of Goa. In December, 1907, I visited Talevadi in Belgaum, and revisited parts of the Central Provinces ; whilst in January, 1908, I was able to examine Leda Hill in Singhbhum. ~ Cyap. I. ] 7 SCOPE OF MEMOIR. 5 Of the manganese areas not examined by me, Mr. J. M. Maclaren visited the Belgaum and Dharwar districts (in 1905) ; and he has kindly supplied me with notes and specimens from the deposits of these parts. During the field season of 1906-07 Messrs. H. Walker and A, M. Heron, whilst working in the Jhabua State, were able to examine some unimportant deposits not visited by me ; I have made use of their notes in amplifying the account of the deposits of Jhabua. It will thus be seen that some considerable time has elapsed since the main body of the field work was carried out. Before the investigation was begun, the little knowledge we had about this mineral did not lead us to expect results of more than ordinary interest. The field-work, however, showed that the manganese-ore deposits are in some parts, notably the Central Provinces, Vizagapatam, Jhabua, and Narukot, associated with most interesting and fascinating series of rocks ; and that the deposits themselves contain many rare minerals and not a few spe- cies and varieties new to science. It was felt that even bare justice could not be done to the subject without a somewhat detailed investigation of these rocks and minerals, Further, during the laboratory examination of these specimens, fresh specimens, and information relative to the discovery of new deposits of manganese-ore, have been pouring in from miners and pros- pectors in all parts of India. Hence the delay in the appearance of this account of the Indian manganese-ore deposits. The gap has been to a certain extent filled by the publication of the paper entitled ‘Manganese in India’, referred to on page 11. It was read on March 26th, 1906, and published in the autumn of the same year. I have endeavoured to treat the subject of this Memoir with some fullness, from each of the following points of view :—Mineralogical (Part !), geological and genetic (Part II), economic (Part III), and descriptive (Part IV). I have not, however, been able to keep in touch with all the fresh discoveries, and can usually give only meagre accounts of deposits not visited by myself or one of my coileagues. Even whilst this work is passing through the press fresh discoveries are being made, accounts of which it will be impossible to include. But although I have not been able to examine every known deposit, I do not think I have missed any important type. In the descriptive part of this Memoir I have given fairly detailed accounts of a large number of deposits, It might be thought that a Scope of this Memoir. 6 MANGANESE DEPOSITS OF INDIA: INTRODUCTION. [ Part I: general account of the deposits of each type would have been suffi- cient. Almost every deposit, however, has its own peculiarities and interesting features, structural, mineralogical, or petrological; whilst such details of the structure of each deposit as can be given will be very useful to the mining community, in helping to the rational develop- ment of the deposits. In the mineralogical section I have described several new species and varieties of minerals, in sufficient detail to war- rant the bestowal of new names ; most of these descriptions are, however, incomplete ; but I hope that it may be possible in the future to investi- gate some of the many points that still require elucidation. There are several other minerals that are probably new, but which I have not been able to examine in any detail. Nevertheless for the sake of convenience and future reference, I have given an account of their characters as far as they have been determined ; these points may require some modifi- cation when the minerals are examined in more detail. During the microscopic examination of thin sections of the rocks, I detected several other minerals that were not visible macroscopically, and could not be identified at the time. Whether they are new minerals, or previously known but rare minerals, has not been determined. They are not mentioned in this Memoir. As the fulness of the mineralogical treat- ment might render this work less useful to mining men, and prevent it from being of use to them in the identification of the minerals they find, I have inserted at the head of each of the more important minerals a short account of its chief features as given in Dana’s System of Mineralogy, 6th Edition, and appendices.’ Further, I have added a chapter on the identification of the Indian manganese minerals, which will, I hope, enable anyone with a little mineralogical knowledge to iden- tify the minerals commonly found in the Indian manganese-ore deposits. The treatment of the economic side of the subject is not as full asI should have liked, particularly with regard to the details of costs of working and despatch to the smelting centres; but that the mining community should often be reticent on these points is not surprising, considering the keen competition that exists in the manganese industry, Such information as I possess relative to the economics of the subject has been obtained through the courtesy of the various members of the mining community, com- panies, syndicates, and individuals. Further, I must express here my indebtedness to the various companigs and syndicates for the permission, Acknowledgments. i Tt is this edition of this well- mont work that T shall refer to" as Dat 7a’s Mineral, ogy in the body of this Memoir. Cuap. I. | ACKNOWLEDGMENTS. ii always readily given, to visit their properties and publish freely any information obtained. I am also deeply grateful to the managers of these companies and syndicates, and to the managers of the various mines, for the courtesy with which they have in every way facilitated my visits to their properties ; for the readiness with which they have answerea questions, sometimes, perhaps, of too inquisitive a nature ; and lastly for the kind way in which they have often personally shown me the main features of their deposits, so that I have been able to carry out a detailed examination with the salient points already grasped. I cannot do better than quote here a remark of that eminent expon- ent of the science of ore-deposits, Professor Franz Posepny. In his work entitled ‘The Genesis of Ore-Deposits ’, p. 3, (1902), he says ‘Mining, indeed, constantly furnishes fresh evidences in new openings, but it destroys the old at the same time; and if these are not preserved for science before it is too late, they are lost forever. The whole mining industry is in its nature transitory; but the nation, which intrusts to the miner, upon certain con- ditions, the extraction of its minera! wealth, has a right to demand that the knowledge thus gained at the cost of a part of the national resources shall not be lost to science.’ Now, although most members of the manganese-mining community of India may not have read this passage, yet they seem to be imbued with the spirit of it. They do not, as arule, record these ‘fresh evid- ences ’ themselves ; but they are only too willing to draw the attention of the geologist to the discovery of what seems to them an interesting or important exposure or mineral, and further to facilitate in every way his personal visit to the place of interest and examination of the same. The fault of the non-recording of every interesting piece of geological interest exposed lies perhaps with the geologist, for he is often unable, from pre-occupation with other work, to accept an invitation to visit the point of interest. This fault is, however, not personal, but due te the fact that a comparatively small body of men have the guardianship, so to speak, of the mineral resources of an area that is almost as big as a continent and out of all proportion to their numbers. If the members of the Indian manganese-mining community find this Memoir of interest or value to themselves, I shall be happy if they realize that it has only been rendered possible through their cordial co-operation and friendly interest, The various companies, syndicates and individuals to whom I am indebted in the various ways specified above are the following :— Bombay Company, Limited ; Central India Mining Company, Limited ; Central Provinces Prospecting Syndicate ; Indian Manganese Company, 8 MANGANESE DEPOSITS OF INDIA: INTRODUCTION. [ Part I: Limited; Jambon & Cie; Gordon, Woodroffe & Co.; Jessop & Co.; Kiddle, Reeve & Co.; P. Macfayden & Co.; Macqueen Bros. ; Madhu Lall Doogar Mining Syndicate ; New Mysore Manganese Co., Limited ; Peninsular Minerals Company of Mysore, Limited; Shaw, Wallace & Co. ; Shimoga Manganese Company, Limited. Messrs. R. O. Ahlers, C. Aubert, F. G. Anderson, Cooverjee Bhoja, P. N. Bose, T. Caplen, W. H. Clark, W. W. Coen, H. D. Coggan, R. T. Coggan, and R. D. Connell; Dr. A. K. Coomaraswamy ; Messrs. K. C. Cowasji and E.S. T. Davies ; Miss A. E. Dawson ; Messrs. O. Dodsworth, P. C. Dutt, W. J. Eales; F. A. H. East, J. J. Evans, C. S. Fawcitt, H. B. Geeson, A. Ghose, J. H. Goodchild, P. Gow, H. M. Hance, H. R. Holmes, H. St. John Jackson, 8S. Kiddle, D. Laxminarayan, C. E. Low, H. C. McNeill, G. M. Prichard, H. E. E. Proctor, R. 8. Rennie, A. D. Sanders, F. L. Schwenk, H. Kilburn Scott, and I. Shrager; Dr. W. F. Smeeth; the late Mr. A. M. Gow Smith; Messrs. H. F. Strickland, 8. G. Stromquist, A. H. Whittle, A. Whyte, W. Whyte, H. J. Winch, C. M. P. Wright, and E. L. Young. In addition, my thanks are due to certain of the officials of the districts and States I have had occasion to visit, for help given me whilst moving in their respective areas ; and to certaii of my colleagues, particularly Dr. Holland,! Messrs. Middlemiss and Vredenburg, and Dr. Christie, for their kindly suggestions and criticisms. I have also to thank Mr. H. B. W. Garrick, Artist to the Geological Survey, for several excellent photo- graphs of mineral specimens, to which, however, justice has not been done in the reproduction. Further, two students—G. G. Narke of Nagpur and Kiran Sengupta of Caleutta—working in the laboratory of the Geological Survey of India, have given me considerable help in testing minerals, taking specific gravities, and compiling statistics. A work of this sort would have been impossible without a consider- able number of analyses, both of ores and picked mineral specimens, Forthese I am largely de- pendent on a series of 84 partial and complete analyses carried out at the Imperial Institute by Mr. G. 8. Blake, under the supervision of Professor W. R. Dunstan, and toa further series of 67 partial and complete analyses carried out by Messrs. J. and H. S. Pattinson of Noweastle-on-Tyne. These have been supplemented by several other analyses, particularly of picked specimens of minerals, carried out in the Geological Survey laboratory, chiefly by Mr. T. R. Blyth, Assistant Curator of the Geological Museum, but partly by my colleague, Mr. J. Analytical work. 1 Now Sir Thomas H. Holland, K,C.I1.E, Cuap. I. ] LITERATURE OF INDIAN DEPOSITS. 9 Coggin Brown, and by myself. Messrs. Winch and Fawcitt have also kindly analysed a few specimens of manganese minerals. Further I have been supplied with a considerable series of analyses by the various manganese mining companies, carried out partly by their own chemists, and partly by well-known firms of chemists in England: the chemists in India to whose analyses I have had access are Messrs. R. D. Connell, H. H. Dains, C. 8. Fawcitt, S. A. Jones, G. M. Prichard, V. G. Speira, H. J. Winch, and Dr. Schulten ; whilst the English firms are Messrs. J. and H.S. Pattinson of Newcastle-on-Tyne, Pattinson and Stead of Middlesborough, W. N. Pearson & Co. of London,-and E. Riley of London. The fact that I have not taken any samples for analysis of the ores of Southern India—Sandur, Mysore, Goa, and Belgaum—may give rise to comment; the reason is that I was not able to visit these parts until this work was practically finished. Should any mineralogist or geologist become sufficiently interested in the manganese-ore deposits of this country to pay it a visit, he will be well repaid for his trouble. If he wish to see the pick of the deposits, let him visit Kandri, Baldghét, Garbham, Kajlidongri, and Kumsi; if he wish to feast his eyes upon apparently endless and unlimited supplies of ore, let him visit the Kamdtaru section of the Sandur Hills; and if he would like an exciting time amougst the minerals and rocks, let him visit Kacharwahi, Sitapdr, Kajlidongri, Mansar, and Kodur, for from any one of these deposits he could collect in a day material sufficient to provide him with months of research work, whilst he would probably find minerals he had not seen before, and possibly varieties and species new to science. I am sure the managers cf the various companies would gladly grant him permission to visit their properties, provided his objects were purely scientific. Should any one be unable to visit India and yet desire to work out any of the numerous points I have left untouched, and only a small proportion of which I can ever hope to deal with myself, I am sure the Director of the Geological Survey would gladly let me supply such material as I have, The visitor to India, In the course of this investigation I have, of course, collected and ex- {ea ae amined all the literature I could find on the manganese-ore deposits. Subject of manganese in India. From the list of papers given at the end of this work it will be seen that the subject has apparently been extensively dealt with before. This is not the case; for most of these references are of trivial 10 MANGANESE DEPOSITS OF INDIA: INTRODUCTION [ Parr. I: importance, being mere records or short accounts of isolated occur- rences. Some of them, however, are of more importance, and to these I shall here refer. Leaving out a vague reference by Dr. W. Ainslie’ in 1813 to the occurrence of manganese in Mysore, the earliest references to the occurrence of manganese in India are contained in two papers by Captain F. Jenkins? and Dr. H. W. Voysey’, respectively, dealing with the mineralogy and geology of the Nagpur area, Central Provinces ; the manganese-ore deposits referred to occur in crystalline limestone and are described in this Memoir as the Junaw4ni and Ghogara deposits. After this Lieutenant (and later Captain) T. J. Newbold, F.R.S., in a series of papers on the mineralogy and geology of Southern India published between the years 1840 and 1846, mentions several occurrences of manganese-ore in Madras, Bombay, Mysore, and Haidardbad. Of these the most important are the accounts of the occurrence in the Kappat Gudda at Chik-Vadvati 4 [the Chick Wodoorti of Newbold], and of the lateritic manganese-ore of Bidar in Haidarabéd 5. In 1852 Dr. A. J. Scott6 published an account with analyses of two specimens of manganese-ore from the Vizagapatam district, he being the first to discover the existence of braunite in India. In 1879, F. R. Mallet published two papers entitled ‘On Braunite, with Rhodonite, from near Nagpur, Central Provinces’7, and ‘On Pyro- lusite with Psilomelane occurrmg at Gosalpur, Jabalpur District’ 8, On pages 326-332 of Part III, Economic Geology, of the Manual of the Geology of India, published in 1881, V. Ball gave a very good summary of all that had been written previous to this date on the subject of Indian manganese-ores. To this work I shall refer in the body of this Memoir as Ball’s Economic Geology. A further paper by F. R. Mallet, entitled ‘On Lateritic and other Manganese Ore occurring at Gosalpur, J abalpur district’9, was published in 1883; whilst the same author on pages 55-59, 61, 62, 84, 90, 113, 139, 140, of Part IV, Mineralogy, of the 1 ‘ Materia Medica of Hindoostan’, p. 57. 2 Asiatic Researches, XVIII, pt. 1, pp. 208, 210, (1833); abstract in Glean. Sci., if, pp. 226, 227, (1829). 3 As. Res., XVIII, pt. 1, p. 127, (1833) ; abstract in Glean. Sci., I. p- 28, (1829), 4 Madras Jour. Lit. Sci., XJ, pp. 44-46, (1840) ; and Jour, Roy. As. Soc., VIL, pp. 212-214, (1843). Jour. As. Soc. Beng., XIII, pp. 992-995, 1002, (1844),‘ Edin. New Phil. Jour., LILI, pp. 277-279, (1852). Rec. Geol. Surv. Ind., XII, pp. 73, 74, (1879). Ibid., pp. 99, 100. Ree, Geol, Surv. Ind., XVI, pp. 116-118, (1883). conan Cuap. I. ] LITERATURE OF INDIAN DEPOSITS. 11 Manual of the Geology of India, published in 1887, gave a summary of what was then known about the Indian manganese minerals. To this work I shall refer as Mallet’s Mineralogy. After this, two important papers entitled ‘The Manganese-iron and Manganese-ores of Jabalpur’ ! and ‘The Manganiferous Iron and Manganese ores of Jabalpur 72, respectively, were written by P. N. Bose, then of the Geological Survey of India. The former paper deals with the economic results of an examination of the deposits round Gosalpur and Sihora in the Jabalpur district, Central Provinces, and the second with their geological occurrence and origin. My own work has been summarized in Dr. Holland’s Review of Mineral Production and in his General Reports on the work of the Geological Survey of India3; whilst I have so far published the following papers relative to the Indian manganese-ore deposits :— . Analyses of Manganese ores.‘ . ‘A new form of blue Amphibole from Central India.’® . ‘An unusual occurrence of Common Salt.’® . ‘Notes on the Petrology and Manganese-Ore Deposits of the Sausar Tahsil, Chhindwara district, Central Provinces.’7 5. ‘On Manganite from the Sandur Hills.’8 6. «On the Association of Gibbsite with Manganese-ore from Talevadi, Bel- gaum district, and on Gibbsite from Bhekowli, Satara district.’9 mown = 7. «Manganese in India.’ Of these, the last-named paper was published in the Transactions of the Mining and Geological Institute of India, Vol. I, pp. 69-131 (discussion pp- 221-233). Besides various woodcuts and photographs of manganese mines it contains three maps. It is at present out of print, but is being reprinted and will probably be available again before this Memoir. Those who require only a brief outline account of Indian manganese-ore deposits, I would refer to the paper mentioned rather than to the pre- sent Memoir. _ Rec. G. S. I., XXI, pp. 71-89, (1888). Op. cit., XXII, pp. 216-226, (1889). Rec. G. 8. I., XXXII, pp. 56-59 and 144-146, (1905) ; XXXII, pp. 94-100, (1906) ; XXXV, pp. 22, 23, 38-40, (1907). Op. cit., XX XI, pp. 47, 48, (1904). Ibid., pp. 235, 236. Ibid., p. 237. Op. cit., XX XIII, pp. 159-220, (1906), with map and photo-micrographs. Ibid., pp. 229-232, with photo. Op, eit, XXXIV, pp. 167-171, (1906), with photo-micrographs, w vo Canton p 12 MANGANESE DEPOSITS OF INDIA : INTRODUCTION. [ ParT I: It was my original intention to render this Memoir more complete Gt ate and generally useful by including in it a brief manganese-ore deposits. account of the foreign deposits of manganese-ore. On going into the question, however, I found the literature about this mineral to be so voluminous and the deposits so numerous, that to do justice to the subject it would be necessary to increase the size of this work much beyond its present dimensions. Conse- quently I have decided to omit any account of the foreign deposits except for comparative references in the text. Instead, however, I will give a short bibliography, which makes no pretension to completeness, but gives some of the more important papers dealing with this mineral. By looking up these references, especially those dealing with the subject in a general way, it will be possible for anyone to obtain access to practically all the available literature. By far the best general account of the manganese-ore deposits of the world is contained in A. W. Stelzner and A. Bergeat’s ‘ Die Erzlager- stitten ’, the first of the references classified under ‘ general’ below. In this work the deposits are classified according to their origin and mode of occurrence, whilst copious references are given to the literature of the subject. List of Literature of the Foreign Manganese-ore Deposits. General. 1. A. W. Srenzner & A. Berceat, ‘Die Erzlagerstaitten’, pp. 239-264, (1904); 571-576, (1905-06), Leipzig. 9. BE. Fucus and L.de Launay ‘ Traité des Gites Minéraux et Métalliféres’, II, pp. 1-32, (1893), Paris. 3. R. Beck & W. H. Weep, ‘ The Nature of Ore Deposits’, pp. 104-111, 198, 199, 535-538, (1905), New York. 4. Leon Dormaret, ‘Les principaux gisements des Minerais de Manganése du Monde’, Annales des Mines de Belgique, X, pp. 809-901, (1905). 5. J.D. Weexs & J. Birxinsrne, articleson Manganese in the * Mineral Resources of the United Siates’ from 1885 to date, U.S. Geol. Surv. 6. Articles on Manganese in the annual volumes of ‘ The Mineral Industry’, 1891 to date, New York. 7. F. P. Dunnrnaton, © On the formation of deposits of Oxides of Manganese’, Am. Jour. Sci., 3rd series, XXXVI, pp. 175-178, (1888). g. R. A. F. Penrose, Jr., The Chemical Relation of Iron and Manganese in Sedi- mentary Rocks’, Jour. of Geol., I, pp. 356-370, (1893). 9. G. BertraNp, ‘ Le Manganése dans la nature’, Revue Générale de Ohimie, VIII, pp. 205-217, (1905). Arranged according to continents and countries. Africa. Cape Colony :— 1. Mining Journal, 21st April, 1906, p. 509, Cuap. I. ] LITERATURE OF FOREIGN DEPOSITS. 13 America, Brazil :— 1. J. C. Branner, ‘The Manganese-Deposits of Bahia and Minas, Brazil’, Trans. Amer. Inst. Min. Eng., XX1X, pp. 756-770, (1900). 2. H. K. Scort, ‘ The Manganese Ores of Brazil ’, Jour. Iron Steel Inst., No. I of 1900, . 179-218. i 3. O. A. Dersy, ‘ On the Manganese Ore Deposits of the Queluz (Lafayette) District, Minas Geraes, Brazil’. Amer. Jour Sci., XII, pp. 18-32, (1901). 4. J. Brrgmpine (0. A. Derzy and others), Min. Res. U. S., 1898-99, pp. 140-142 ; 1901, pp. 140-143. 5. H. K. Scorr, ‘ O Manganez no Brazil’, Jornal do Commercio, Rio de Janeiro, 1902, 58 pages. 6.0. A. Dery, ‘O Manganez em Nazareth’, Boletim da Secretaria de Agriculiwra SAG SOGC do Estado da Bahia, V, pp. 62-65, (1905). 7. M.A. Laspoa, ‘ Report on the Manganese Ore Deposit of Morro da Mina ’, Brazit- ian Engineering and Mining Review, 111, Nos. 6 and 7 ; reprint of 21 pages, received 1907. Canada :— 1. R. A. F. Penrost, Jr., ‘Manganese: Its Uses, Ores, and Deposits’, Ann. Rep. Geol. Surv. Arkansas for 1890, Vol. I, pp. 496-538. 2. E. D. Incatt, Section on Manganese, Ann. Rep. Geol. Surv. Canada for 1902-3, pp- 148s-169s. Chile :— 1. Weexs & Brexinerne, Min. Res. U. 8., 1894-95, pp. 439-443; 1898-99, pp. 142-147. 2. Beck & WEED, p. 110, (1905). Columbia :— 1. E. J. Cutpas, ‘ The Manganese-Deposits of the Department of Panama, Republic of Columbia’, Trans. Amer. Inst. Min. Eng., X XVII, pp. 63-76, (1897). 2. E. G. Wittams, ‘The Manganese Industry of the Department of Panama, Republic of Columbia’, Op. cit., XX XIII, pp. 197-234, (1902). Cuba :— 1. Wrexs & Brmxrsine (FE. J. Chibas), Min. Res. U. S., 1891, pp. 142-148; 1896-97, pp. 312-3 ; 1899-1900, pp. 146-9. a ‘ . H. C. Brown, Civil Report of the Military Governor of Cuba, Vol. V (quoted in the Min. Res. U. S.). ¢ Fe aE 3. A. C. Spencer, ~The Manganese deposits of Santiago Province, Cuba’ } Min. Jour., 23rd Aug. 1902, pp. 247-8. i : Ea ne Mexico :— + |. E. Hatsz, ‘Notes on the Occurrence of Manganese Ore near Mulegé, Baja Cali- fornia, Mexico’, Trans. North of Eng. Inst. Min. & Mech. Eng., XU, pp. 302-307, (1899). 2. J. G. Acumrra, “The Geographical and Geological Distribution of the Mineral Resources of Mexico’, Trans. Am. Inst. Min. Eng., XXXII, p. 505, (1902), United States of America :— 1. R. A. F. Punrosr, ‘Manganese: Its Uses, Ores, and D its’ g Surv. Arkansas for 1890, Vol. 1, (1891). ile pa 2. F. L. Nason, * The Franklinite- Deposits of Mine Hill, Sussex County, N ; Trans. ee Inst. Min. Enj., XXIV, pp. 121-130, (1894). ee Pn le 3. J. F. Kump, ‘The Ore Deposits of the United Stat d Cs a” i fe aan ates and Canada’, 4th edit., pp. 4, T. L. Watson, ‘ Geological Relations of the Manganese Ore-D its xe0rgia’ Trans. Am. Inst. Min. Eng., XXXIV, pp. 207-258, (1903). Be aay one 5. J. E. Wotrr, * Zinc and Manganese Deposits of F anklin Furn: > q Geol, Surv., Bull No, 213, pp. 214-217, (1903) Peeenee a RA glee 14 MANGANESE DEPOSITS OF INDIA: INTRODUCTION. [ Part I: 6. Wrexs & Birgmnsinr, The Mineral Resources of the United States’, 1885 to date. 7. ‘ The Mimeral Industry ’, Vol. I (1891) te date. Asia Borneo :— 1. A. DreseLporrr, ‘Neue Manganerz-Vorkommen in Britisch Nord-Borneo’, Zeitsch. f. prak. Geol., XIV, pp. 10-11, (1906) ; abstract in Yrans. Min. Geol. Inst. Ind., I, p. 182, (1906). : Cyprus :— 1, A. Gaupry, ‘ Géologie de Vile de Chypre ’, Mém. Soc. géol. de France, 2nd series, VII, pp. 191-2, (1860). Japan :— 1. ‘ The Mineral Industry ’, X, p. 446, (1901). Java :— 1. ‘ The Mineral Industry ’, X, p. 446, (1901). Turkey-in- Asia :— 1. ° The Mineral Industry , VII, p. 504, (1898). 2. L. Dommntan, ‘ Mining in Turkey’, Lng. Min. Jour., 4th Aug. 1904, p. 185. Australasia. New Zealand :— 1. Weexs, Min. Res. U. 8., 1893, p. 154, Queensland :— 1. L. C. Batt, ‘Some Manganese Deposits in the Gingin, Degilbo and Warwick Districts’, Geol. Surv. Queensland, Publication No. 189, pp. 1-10, (1904). 2. ‘ The Mineral Industry’, XI, p. 464, (1902). Europe. Austria :— 1. B. Watter, ‘ Die Erzlagerstatten der stidlichen Bukowina’, Jarhb. d. k. k. geol. Reichsanst, XXVI1, pp. 373-382, (1876). 2. L K. Mossr, ‘ Manganerzvorkommen von Kroglje bei Dolina in Istrien’, Verhandl. d. k. k. geol. Reichsanst., Vienna, 1903, pp. 380-381. Bosnia :— 1. B. Waxter, ‘ Beitrag zur Kenntniss der Erzlagerstitten Bosniens’, pp. 44-72, 1887). S My Other papers cited by Stelzner & Bergeat, p. 252. 3. F. Karzer, ‘Die geologischen Verhialtnisse des Manganerzgebietes von Cev]- janovié in Bosnien’, Berg-u. H tittenmdnnisches Jb. d. k. k. mont. Hochschulen zu Leoban u. Pribram, LIV, pt. 3, 42 pages, (1906) ; abstr. in Geol. Centralbl., VIII, pp. 507-510, (1906). France :— : J, M. Bravary, ‘Note sur les gites de manganése des Hautes-Pyrénées’, Bull. Soc. Géol., France, XVII, pp. 297-301, (1889). 2. C. A. Morete, ‘The Manganese Mines of Las Cabesses, Pyrenees, France’, Trans. Inst. Min. Met., Ul, pp. 250-264, (1894). Cnap. I. | LITERATURE OF FOREIGN DEPOSITS. 15 3. A. Lacrorx, ‘Sur les minéraux des gisements manganésiféres des Hautes- Pyrénées’, Bull. Soc. Franc. Minér., XXIII, pp. 251-255, (1900). 4. E. Fucrs & L. pe Launay ‘Gites Minéraux’, II, pp. 13-16, (1893). Germany :— The numerous deposits are often of considerable interest, but are of little economic importance. References to the copious literature are given in :— 1. SretzNeR-BERGEAT, pp. 250, 573-575, (1904-1906). Of papers not quoted in (1) the following may be mentioned :— 2. R. Detxesxame, ‘ Die hessischen u. nassauischen Manganerzlagerstatten, etc.’, Zeitsch. f. prak. Geol., 1X, pp. 356-365, (1901). 3. J. Betirmarr, ‘Uber die Entstehung der Mangan und Eisenerzvorkommen bei Niedertiefenbach im Lahntal’, Zeitsch. f. prak. Geol., XI, pp. 237-241, (1903); also pp. 68-70. Great Britain :— 1, E. Hatsr, ‘ The Occurrence of Manganese Ore in the Cambrian Rocks of Merionethshire ’, Trans. North Eng. Inst. Min. Mech. Eng., XXXVI, pp. 103-117, (1887). 2. Werks, Min. Res. U. S., (1886), pp. 199-200 ; (1887), pp. 154-159. 3. H. pe LA Brcur, ‘ Report on the Geology of Cornwall, Devon, and West Somerset’, pp. 609, 610, (1839). Greece :— 1. ‘ The Mineral Industry ’, VII, X, XII, (1898-1903). _ 2, Osterr. Zeitsch. f. Berg- u. Hiittenw., LXV, p. 514, (1897); quoted in SreLzNeER. BERGEAT, p. 260. Hungary :— 1 F. Kossmar & C. V. Joxuy, ‘Das Mangan-Eisenerzlager yon Macskamezé in Ungarn ’, Zeitsch. f. prak. Geol., XIII, pp. 305-325, (1905). Italy :-— 1. SretzNer-Bereeat, p. 253, (1904). 2. Dr Saussure, ‘ Voyage dans les Alpes’, VIII, p. 229, (1796) ; Fucus & Launay, II, p. 9, (1893). Portugal :— 1. Brrxrnsine, Min. Res. of the U. S., 1901, pp. 149, 150. Russia :— 1. P. Stevens, ‘Report on the Manganese Ore Industry of Sharopan’, Foreign Office Reports, No. 307, 8 pages, London, (1893). 2. F. Draxe, ‘The Manganese-Ore Industry of the Caucasus’, Trans. Am. Inst. Min. Eng., XXVIII, pp. 191-208, 841, (1898). 3. F. Draxs, ‘ The Nicopol Manganese District in Southern Russia’, ‘The Mineral Industry’, X, pp. 447-455, (1901). 4. N. Soxoxoy, ‘ Die Manganerzlager in den tertidren Ablagerungen des Gouverne- ments Jekaterinoslaw ’, Mémoires du Comité géologique, St, Petersburg, XVIII, No. 2, pp. 61-79(1901) ; abstr. in Trans. N. Eng. Inst. Min. Eng., LILI, Appendix I, pp. 90, 91, (1904). 5. A. Kanpertaxt, ‘Das kaukasische Manganerz’, Ghickauf, 17th June 1905, pp. 764-767. 6. G. LrsrepEw, ‘ Die Kornilow’sche Schlucht und das Vorkommen yon Rhodonit im Ural ’, Verh. d. kais. russ. min. Gesellsch., 2nd Ser., XIII, p. 1, (1878); abst. in Zeitsch. f. Kryst., Il, pp. 501-502, (1878). Sardinia :— 1. E. Hatsz, ‘On the Manganese Deposit of the Islet of San Pietro, Sardinia’ Trans. North Eng. Inst. Min. Mech. Eng., XXXIV pp. 145-158, (1885). 2. Fucus & Launay, pp. 25-26, (1893) 16 MANGANESE DEPOSITS OF INDIA: INTRODUCTION [ Part I: Spain :— 1. Fucus & Launay, pp. 22-25, (1893). 2. J. A. Jones, ‘The Covadonga Manganese District and its Mines’, Trans. Inst. Min. Met., 111, pp. 263-274, (1894-95). 3. F. Jounson, ‘The Manganese Deposits of Huelva’, Ibid., pp. 275-284. 4. C. Dorrscu ‘The Manganese Ore Deposits of the Province of Hue va’, The Mining Journal, ‘7th Dec. 1901, p. 1529. Sweden :— 1 Numerous papers quoted in StrtzNeR-BeRGEAt, pp. 40, 241 , (1904) 2. Beck & Wexrp, pp. 104-106, (1905). 3. J. D Werexs. (K. A. Wattrotn), Min. Res. U. S., 1894-95, pp. 449-451 1895-96, pp. 217-220. Turkey :— 1. ‘The Mineral Industry’, VII, XIII, XIV, (1898, 1904, 1905). 2. L. Domrntay, ‘ Mining in Turkey’, Lngineering Min. Jour., 4th Aug. 1904, p. 185. 3. B. Noaara, ‘ Mining in Turkey’, Mining Mag., XIII, pp. 13-14, (1906). Nature of Manganese and its Distribution in Nature ?. Manganese in the elementary form is a metal belonging to the man- ganese-iron group of elements, comprising man- ganese, iron, cobalt, and nickel, which, owing to their more or less similar chemical properties, often occur in association in Nature. When pure, metallic manganese is said to be of a greyish white colour. It is, for a metal, extremely hard, cutting both glass and hardened steel. In the following table some of its physical constants are compared with those of the other members of the group.2 Nature of Manganese. TABLE 1. Physical constants of the manganese-tron group of elements. Atomic Specific Atomic Specific Melting Symbo). |weight. gravity. volume. heat. point. ae or a f Cc. Manganese . : . sda 55:0 8:00 6-9 O'110 | 1245° Tron a $ : é Fe. 55°9 7°86 (el 0-114 1600° Nickel! 2 : A a ae 58°7 8°80 6-7 0108 1470° Cobalt . . . «| Co | 890 | 880 | 67 | o704 | qoR0e 1 See also the very interesting work by R. A. F. Penrose, Jr., An. Rep. Geol. Surv. Arkansas for 1890, Vol. I,“ Manganese : Its Uses, Ores and Deposits’, pp. 1 to 56; and a more recent paper by G. Bertrand entitled ‘ Le Manganése dans la nature’, published in the Revue Générale de Chimie, VIII, pp. 205 to 217, (1905). 2 Roberts-Austen, ‘An Introduction to the Study of Metallurgy ’, pp. 72, 73, (1898), with severa alterations in accordance with later research! Cuap. I. ] ORIGIN OF WORD ‘ MANGANESE ’. 17 Manganese does not occur in nature in the metallic condition, but only Origin of the word in combination, usually in the form of oxide, man- * manganese ’. ganate, carbonate, cr silicate. In the form of oxide manganese has been kncwn from very early times. Pliny considered the oxide to be a form of magnetite or lodestone, calling both substances magnes manganese oxide being of the feminine gender and not attracting iron!. In the middle ages both the black oxide of manganese and the white oxide of magnesium were known as magnesia, being distinguished as magnesia nigra and magnesia alba, respectively. In the Dictionnaire de Chymie of Macquer? published in 1778, that is, just after the recognition of manganese as a new ele- ment, three sorts of magnesia are distinguished. These are magnésie calcaire, magnésie @ Epsom and magnésie noire, the last named being even then also known as manganése and savon de verre ; the latter name refers to the property of manganese peroxide of removing from glass the greenish colour due to the presence of ferrous iron. It is not known how or when the word manganese originated. Itis supposed by some to have been derived from magnesia nigra by metathesis or interchange of letters. In Latin manuscripts of the sixteenth century it appears in the form lapis manganensis, and still later as manganesium3. In his * Opuscula Physica et Chemica’, (1788)4, Bergmann, in giving an account of the then newly discovered metal, gives it the Latin name of magne- sium, from magnesia nigra. According to Bertrand5, Guyton de Morveau proposed to translate this term magnesium into French not as magnésie, as this would have caused confusion, but as manganése. Since then the latter term has been used in science, the English form of the word being, of course, manganese. Until 1740, when Pott 6 showed that black oxide of manganese does R rs not contain iron, whilst it yields a definite series ecognition as a new - : element. of salts, the oxides of manganese and iron were con- founded one with the other. But Pott did not suggest that oxide of manganese contains a metal. Indeed, according to Bertrand’?, Bergmann was the first to give serious reasons for 1 Roscoe & Schorlemmer, ‘ Treatise of Chemistry’, Vol. II, Part II, p-L 1879. 2 Quoted by G. Bertrand, loc. cit., 205. 3 Roscoe & Schorlemmer, Joc. cit., p. 2. 4 Quoted by Bertrand, loc. cit., p. 206. 5 Loc. cit., p. 206. 6 ‘Examen chymicum magnesia vitrariorum, Germanis Braunstein, (Roscoe & Schorlemmer, loc. cit., p. 2.) 7 Loe. cit., p. 205 t c 18 MANGANESE DEPOSITS OF INDIA: INTRODUCTION. [ Part I: classifying manganese oxide amongst the calxes rather than amongst the earths. At Bergmann’s request, Scheele experimented on manga. nese, and, although he did not succeed in isolating the metal, he discovered sufficient of the characters of its compounds to show the existence of a new element!. Two years later (1776) Gahn succeeded in isolating the metal?2. Of all the elements manganese is one of the most widely distributed Rn Vide. throughout the three kingdoms of Nature; it is Distribution in Nature. : . - uc to a large extent co-extensive with iron in its occurrence. The total number of well-defined minerals yet found in the earth’s pho heed cee crust, either in its rocks or its mineral deposits, mineral kingdom. is in round numbers about 1,000. Of these about 130 to 140 contain manganese as an essential constituent, whilst many more often contain it in less important quan- tities. The consequence is that most of the rocks of the earth’s crust contain manganese, though usually in small proportion only. According to F. W. Clark3 0°10 per cent, of the earth’s crust consists of manga- nese protoxide (MnO), manganese ranking as the fifteenth most import- ant element in this respect. As the result of the decomposition and denudation of the earth’s surface by meteoric agencies, its various constituents are carried either in suspension or solution to the sea. It has been estimated by Murray4 that one cubic mile of average river water contains in solution 5,703 tons of manganese sesquioxide (Mn.03), and that 6,524 cubic miles of river water are annually discharged into the sea5, This means that about 37,000,000 tons of Mn,O3, containing nearly 26,000,000 tons of metallic manganese, are brought every year by rivers into the oceans. This process has pre- sumably been going on for untold ages, so that now we should expect to find large quantities of manganese salts in solution in sea-water. This, however, is not the case, and it seems to me that in this dis- appearance of manganese from solution in the water we have the 1 Stockholm Memoirs, 1774 (Kongl. Svenska Vetenkaps-Akademiens Handlingar) ‘ Penrose) ; also see ‘ The Chemical Essays of Charles William Scheele translated from the Transactions of the Academy of Sciences at Stockholm’ by Thomas Beddoes, London (1786), Essay V. 2 Roscoe & Schorlemmer, Vol. II, Part I, p. 2. 3 U.S. Geol. Surv. Bulletin No. 228, p. 19, (1904). 4 Scottish Geographical Magazine, U1, p. 77, (1887). 5 Op. cit,, IV, p. 41, (1888). Cuap. I. ] MANGANESE IN VEGETABLE KINGDOM. 19 explanation of the presence of the large numbers of concretions of manganese oxide that are so abundantly dredged up in nearly all deep- sea exploration work from the bottom of the ocean!. Manganese is also sometimes found in meteorites. It is well-known that plants obtain through their roots a certain pro- portion of their nourishment by the absorption from the soil of water containing mineral sub- stances in solution. In view of the ease with which the manganese minerals are known to undergo decomposition and to pass into solution in surface waters, it is not surprising to find that nearly all plants seem to contain a certain proportion of manganese, presumably obtained from the soil through the medium of their roots. The work on this subject is well summarized by Bertrand in the paper already cited”. It seems that Scheele was the first to detect manganese in plants, finding it in the ashes of the wild cummin and wood. Later, in 1849, Herapath found manganese in the ashes of the radish, turnip, beetroot and carrot ; then Richardson found it in the ashes of the sugarcane and Salm Hortsdar in those of oats. In 1852 Liebig detected both iron and manganese in the ashes of tea and coffee. Since then the amounts of manganese in many plants have been esti- mated, and this element has been recognized as occurring in potato, wheat, grapes, and many other vegetables, fruits, cereals, and wood, in addition to those already mentioned. When working in the field on the manganese-ore deposits I was not aware of the universal distribution of manganese in plants, and collected specimens of wood from trees that were growing actually on the manganese-ore, with the idea of seeing if they had taken up any manganese. [I also collected some specimens of bamboo from the top of a laterite hill in the Balaghat district in the Central Provinces to serve as a blank so to speak; for this laterite did not contain any visible manganese oxide. I only had time to deal with this sample. It was divided into short lengths, the outside cut off and rejected, and then 533°5 grammes of the wood were incinerated in a platinum dish with the production of 8-8 grammes of ash of a bluish green colour, thus testifying to the presence of manganese in the bamboo. In order to find out if manganese is an essential constituent of plants and not an accidental one, Bertrand made some experiments on the latex of the tree from Tonkin known as Rhus succedanea. It appears that when the bark of that tree is incised a thick, Manganese in the vege- table kingdom. 1 See especially :—Challenger Reports, Vol. on Deep Sea Deposits, (1891). 2 P. 212, I (ol, 20 MANGANESE DEPOSITS OF INDIA: INTRODUCTION. [ Parr I: whitish juice exudes, which rapidly turns first brown and then black on exposure to the air. This latex consists of laccase, laccol, and water. The laccase is in solution in the water and the laccol is in a finely divided state as an emulsion. The experiments show that the laccase contains manganese and that the latter acts as a carrier of oxygen from the atmosphere to the laccol. Laccol is not present in all plants, but its place is very often taken by analogous chemical substances such as tannin, boletol, and hydroquinone. It appears from these experiments that the presence of manganese is in all probability not fortuitous, but of vital importance to the plant, and connected with the extraction of oxygen from the air, whenever this is necessary for the causation of various chemical changes necessary to the vital activity of the plant. Since all animals live either directly on plants, or directly or ultimately on other animals that eat plants, one would expect manganese to be found in animal tissues. This is found to be the case ; but the presence of manganese in the animal kingdom does not seem to have been so thoroughly investigated as in the case of the vegetable kingdom. Bertrand, in the paper already mentioned, mentions its detection by Vauquelin in hair, Berzelius in bone, Chevreul in mutton grease,- Oidtmann in the liver and human spleen; whilst, according to Millon, du Buisson, and Riche, it occurs in small quantities, namely 1 to 5 milligrammes per kilogramme, in the blood of human beings and other mammals. The proportion of manganese to irorin the human body is said to be 1 to 20 1. Manganese in the animal kingdom. 1 Penrose, /oc. cit,, p. 2. CHAPTER II. MINERALOGY. General. Distribution of manganese in minerals and rocks—Colours of manganese minerals—Occurrence of manganese minerals—List of known manganese minerals —List of Indian manganese minerals—List of associated non-manganiferous minerals—New species and varieties. The total number of well-defined minerals yet found in the earth’s erust, both in its rocks and in its mineral deposits, Wide distribution of jg jn round numbers about one thousand. Of manganese in minerals - and rocks. these more than 100 contain manganese as an essential constituent, whilst many more frequently contain it in less important quantities. The consequence is that most of the rocks of the earth’s crust contain this element, though usually only in small proportion ; and according to F. W. Clark! 0°10 per cent. of the earth’s crust consists of manganese protoxide (MnO), manganese ranking as the fifteenth most important element in this respect. There are many minerals that ordinarily do not contain this ele: ment in appreciable amount. Under somewhat fee, manga- rare circumstances, such as when such minerals have been formed in the presence of large quantities of manganese compounds, as in the metamorphism of manganiferous sediments, a small quantity of manganese may enter into the composition of the mineral with a most remarkable effect on the colour, and therefore frequently on the pleochroism, of the mineral, without affecting its other properties appreciably. As a very good example of this winchite may be mentioned ; this is practically a variety of tremolite, a colourless mineral, but contains small quantities of manganese, iron, and alka. lies, in addition to the usual constituents. The winchite, instead of bemg white or colourless, is blue or lavender in the hand-specimen, and shows very beautiful pleochroism, under the microscope, in shades of lilac and blue. In the same way blanfordite is a pyroxene containing a cer- tain quantity of manganese and alkalies ; in the hand-specimen it is of a deep crimson colour, whilst under the microscope it shows as_ beautiful pleochroism, in shades of blue, carmine, and lilac, as has been noticed 10. 8, Geol. Surv., Bulletin No. 228, p. 19, (1904). 22 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Partl: for any known minera]. Similarly the manganese-micas show various shades of pink, delicate green, orange, and lilac-brown, in thin scales examined under the microscope. As other examples of the effect on the colour of a mineral may be mentioned the manganese-epidote, pied- montite, and the manganese-sphene, greenovite. Excepting the oxides, which are usually of some shade of black or dark grey, the minerals of manganese usually show some variety of blue, pink, lilac, or crimson, whilst orange and yellow tints are found in the garnets. Other colours, such as green and brown, are also found in manganese minerals, but they are of much rarer occurrence. The colour of a given mineral depends, of course, on the other constituents besides the manganese, so that it is difficult to say which colours are specially due to the man- ganese. Thus in winchite and blanfordite, mentioned above, the soda present has perhaps partly contributed to the colour. But a com- parison of the colours of minerals containing manganese with those of minerals otherwise similar but practically free from this constituent points to the fact that the colours specially due to the presence of manganese in a mineral are red, pink, and lavender, and allied tints. Rose quartz and amethyst may also be cited as exhibiting in a remark- able manner the colour effects produced by manganese ; for both these varieties of quartz have been shown to contain this element 1. As regards mode of occurrence manganese minerals exhibit the greatest variety; for they are found in igneous, The occurrence of : : : - manganese minerals, | Metamorphic, and sedimentary rocks, and in mineral veins traversing these rocks, as original minerals formed at the same time as the enclosing rock or vein-filling. In all these rocks and veins they may also be found as secondary minerals formed by the chemical alteration of pre-existing minerals in the rocks or veins, or by the introduction of manganese salts in solution from without. Moreever, by the weathering of these minerals when they are exposed at the surface secondary manganese minerals are frequently formed. The minerals most frequently found are the oxides, which occur in metamorphic and sedimentary rocks and in veins, and per- haps rarely in igneous rocks?. The carbonates are not found in igneous rocks, but are found inall the others. Silicates are especially characteristic of the metamorphic rocks ; they are found somewhat less 1 Rose quartz, see page 212; amethyst, see M. Berthelot, Comptes rindues, CKX XXIII, pp. 477 to 488, (1906). 2. O. A. Derby has ascribed an igneous origin to an ore or rock composed of polianite (MnO2) and spessartite-garnet. Aer. Jour. Sci., X11, pages 26, 30, (1901.) Cuap. IT, | LIST OF MANGANESE MINERALS. 23: often in igneous rocks, rarely in mineral veins, and probably never in sedimentary rocks. The niobates, tantalates, and tungstates, are found either in igneous ! veins, whilst the phosphates, arsenates, and antimo- nates, probably occur in both igneous veins and metamorphic rocks. The titano-silicates are alsc found in igneous and metamorphic rocks. Of the large number of manganese minerals known, only a moderate proportion has been found in India. Taking into account, however, the considerable variety of the Indian manganese minerals yet found—includ- ing members of the groups of oxides, manganates, carbonates, silicates, phosphates, arsenates, niobates, and tungstates—, and the fact that the list of Indian manganese minerals is being constantly extended, one may expect to find almost any cf the manganese-bearing minerals met*with in other parts of the world. Consequently I propose to give here a list of all the well-defined minerals containing a considerable proportion of manganese, together with the formula, crystal system, specific gravity, and hardness of each. The figures given in this list as well as the formule, are almost all of them taken from the sixth edition of Dana’s System of Mineralogy, its Supplement, and Appendix. TABLE 2. List of known manganese minerals with their chief properties. Crystalline Specific Hardness. | Name. Formula. system. gravity. i —_—— eo eae | Alabandite . MnS : - : . | L Tetrahe- | 395404 | 354 dral. | Hauerite . | MnSe E : : . | L Pyritohe- 3°46 4 dral Chlorides— | Seacchite - |MmCl . - : ae) Ae a = SS a =) a ee San] eal MESSE Oxides— | Manganosite . | MnO - - : ie or 5:18 5-6 | 1 Pyrophanite . | MnO.TiO2 4 : - | I. Rhomb- 454 5 : | | tetartohe |: i dral. Bixbyite - | FeO.MnO2 .. - P i. 4°95 6-65 1 Including ‘ aqueo-igneous ’ vems. 24 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: TABLE 2—contd, Inst of known manganese minerals with their chief properties. Crystalline Specific Name. Formula. system, gravity. Hardness. Senaite . (Fe,Pb)0.2(Ti,Mn)O2 . LIL-Trirhom-) 4°78-5°3 6 bohedral. Dysluite (Zn,Fe,Mn)0.(Al,Fe),03 L. 4-46 T5—8 Manganmagne- | (Fe,Mn)O.Fe20, Uh 5°06 | (5°5-6°5) tite. Franklinite . |(Fe,Zn,Mn)O.(Fe,Mn)203 . | ‘i 5:07-5:22 | 5°5-6'5 Jacobsite (Mn,Mg)0.(Fe,Mn).03 I. 4°75 6 Hausmannite | MnO.Mn,03 Il. 4°73-4'86 5-56 Manganoferrite | (Fe,Mn);,0, . (artificial). Crednerite 3Cu0.2Mn,0; Ve 4°9-5'1 4°5 Vredenburgite | 3Mn304.2Fe,0; | 4°74-4'84. 65 Sitaparite 9Mn20;,.4Fe,03,.Mn0;.8Ca0 4°93-5°09 7 Braunite 3Mn20;.MnSiO, ie 4°75-4'82 6-6°5 Polianite MnO, ‘ IL. 4°83-5'03 6-6°5 Pyrolusite MnO, IV (2). | 4°73-4°86 2-2°5 Manganite Mn203.H20_ , IV 4°2-4°4 4 Manganbrucite | (Mg,Mr)OH,0, . | ILL Rhom- | (2°38-2°4) (2°5) bohedral. Pyrocuroite MnO.H20 Ditto . 3°26 2°5 Chaleophanite | (Mn,Zn)O,2MnO02.2H20. Ditto . | 3°91-4'01 2°5 Manganates— | Flollandite m(Ba,Mn).Mn0Os5 + »Fe4(Mn WALEGD) < 4°95 4-6 O5)3- Coronadite R2MnOs, with R = chiefly Fibrous 5°246 4 Mn, Pb. Cuap. II. ] LIST OF MANGANESE MINERALS. ; 25 TABLE 2—conid, List of known manganese minerals with their chief properties. et Name. Formula. | ae a Hardness, Psilomelane . | HiMnO5, with H replaced | Amorphous 3°7-4°7 5-6 by Fe, Mn, Ni, Co, Mn, Ba, Ca, K, etc. Beldongrite . | 6Mn305.Fe203.8H20 . Ditto . 3°22 4 Wad . . | Impure Mn oxides passing | into psilomelane. Ditto . 3°0-4°3 1-6 as 3 — ss Carbonates— Manganecalcite (Ca,Mn)CO3_ . > . | TIL Rhom-| 2°78-2°84 (3) bohedral. Mangandolo - (Ca,Mg,Mn)CO3. - Ditto . | 2°83-2°89 | (3°54) mite. Ankerite . | CaCO3.(Mg,Fe,Mn)COs .j; £Ditto . | 2°95-3°1 3°5-4 Mangansiderite | (Fe,Mn)COs . - ./| Ditto ,| 3°71-3°74| (3°5-4) (oligonite). Rhodochrosite |MnCOs . - . .| Ditto. | 3°453°6 | 3°5-4°5 | Metasilicates— | | ; | Violan . 3 °21-3°27 = Manganiferous diopside . $ | Anthochroite Vv : 5-6 Blanfordite . Probably allied to violan . Ves 315 _t Manganheden- Ca(Fe,Mn)(Si0s)2_—. F Viet 3°55 (5-6) bergite. | Asteroite . | Var. of manganhedenbergite Woo = = Schefferite . | (Ca,Mg)(Fe-Mn)(SiOs)z . e.: - x Jeffersonite . | (Ca,Mg)(Fe,Mn,Zn)(SiO3)2 Vv. 3°36 aa | 26 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [| Parr I: TABLE 2—contd, List of known manganese minerals with their chief properties. Crystalline Specific _ Name. | Formula. system. gravity. Hardness. Urbanite . | (Ca, Mg,Mn) SO +2Na-Fe’” M,, wilh 228 53 5-6 (Si03)2. | Manganpecto- H20.Na20.4(Ca,Mn)0.6Si02 Ves we | 2°84 5 lite. - Livenite . . | (Na4,Cae,Mno,Zr) V. | 3°51-3°55 6 [(Si,Zr)O3 2. | | Rhodonit¢é .|MnSi0p.. - + ‘'.)] “WE = | 3:428ces 5°5-6°5 Bustamite . | (Mn,Ca)SiO3 ie | Fowlerite - (Mn,Zn,Fe,Ca)Si0z VI. itil 3°67 ae Babingtonite . (Ca, Fe,Mn)SiO3 and Fe2(Si View Sus eab-Sn37 5°5-6 O03)3.- Hexagonite . Tremolite containing a little | V. = 3°0 om Winchite | Tremolite containing Fe, | | Na, K, and Mn. V. . | 2°98-308 ms Dannemorite . | (Fe,Mn,Mg)Si03 <3 Was 3°45 | 5°5 vy. silfbergite. | | Richterite __. | [(K,Na)2,Mg,Ca,Mn]Si0z . Vou: 3°09 = Astochite . | (Mg,Mn,Ca)SiO3z and (Na,K,| V. .¢.}-3505-375107 10 ee H)2S8i03. Gamsigradite | Manganese-hornblende . | | V. | ee | | Barkevikite | Mn-amphibole near glau- | V. cophane. oe te ee a ee ——SSSS——— SS ee Intermediate Silicates— Barysilite . | Pb3SizO7 with Mn, Ca, and iI. . | 6°11-6°55 3 Mg. =i, elTSUR® Ganomalite . | PbsSiz07.(Ca,Mn)2Si0s I. . | 4°98-5°74 3 ee ee ey ee Se ee Cuap. II. ] TABLE 2—contd, LIST OF MANGANESE MINERALS. 27 List of known manganese minerals with their chief properties. : = f Crystalline Specific Name. Formula. system. gravity. Orthosilicates— | Helvite . (Mn,Fe)2/Mn2S)Be3(Si04)3 | I. Tetrahe- | 3°16-3°36 dral. Danalite (Fe,Zn,Mn)2 [(Zn, Fe)2S] 3°35-3°43 Be3(SiO4)3. Mangan-gross- | 3(Ca,Mn)O.Al203. 3Si02 Ie 3°24 ularite : Spessartite 3Mn0. Al203. 38i02 Ui 4°0-4°3 Spandite 3(Ca,Mn)O.(Al,Fe)203. i: 3°8-4°1 3 SiOz. Allochroite \T. eRe Pg oon Lipa Palyadelphite eee varieties E eerie 3Ca0.Al203.38i02. | i | Partschinite (Mn,Fe)3Al2Si3012 1 Enaceal 401 Glaucochroite | CaMnSi04 : ; 5 IV. 3°41 Hortonolite (Fe,Mg,Mn)2S8i04 IV. 3°91 Knebelite (Fe,Mn)2S8i04 IV. 3°9-4°17 Tephroite Mn2Si04 Vee oiee 440-12 Roepperite (Fe,Mn,Zn)2Si04 IV. . | 3°95-4°08 Trimerite (Mn,Ca)2Si04. Be2Si04. VI (pseudo. | 3°47 Rhombohe- dral). Troostite (Zn,Mn)2Si04 III. Rhom- | 3°89-4°18 bohedral. Friedelite H7(MnCl)Mn4(Si04)4. Ditto . | 3°06-3°07 Pyrosmalite ae (Fe,Mn)Cil (Fe,Mn)4(Si Ditto . | 3°06-3°19 4)4. Sie a (Oe on eae ee ee ——— Basie Silicates Mangan-vesu-’-| Silicate of Ca,Al,Fe, with > TY, -4.|' (3235-3 :45) vianite. Mn. Mangan-anda- | (Al,Mn)203.Si02 IV. (3 °16-3°20) lusite. Hardness. 6°5-7°5 6°5-7°5 (6 °5) (7°5) MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: TABLE 2—contd. List of known manganese minerals with their chief properties. | : | Crystalline Specific Name. Formula. | system. | gravity. Hardness. Basie Orthosili- cates— Withamite Epidote with small quan- | Ve 3°14 6-6°5 tity of Mn. Piedmontite . | Caz (AlOH) (Al,Mn,Fe)2 V. 3°40 65 (Si04)s Hancockite (Pb,Ca,Sr,Mn)2 [(Al,Fe,Mn). V. 4°03 OH |(Al,Fe,Mn)2(Si04)3 Axinite Boro-silicate of Al, Fe, Ca, | VI. 3:27-3:29 | 6-5-7 Mn. | Acid Orthosilicate~ te Harstigite H7 (Ca,Mn)12Al13 Si1o O40. | LV. si 3°05 5°5 Subsilicates— | Leucophenicite] H2(Pb,Mn,Ca, Zn)7Si3014. V.(2) 3°85 (manganese- humite). Ilvaite HCa Fe’’2 Fe ’” Sig Og with | IV. . | 3:99-4:05 | 5°5-6 often Mn Ardennite H5Mn4Al4VSi4023 TVe . 3:°57-3°62 6-7 Langbanite mSb203.nFe203.pMn’(Mn', III. Rhom- | 4°65-4:92 6 $i)O3. bohedral. Kentrolite . | 2PbO.Mn203.2Si02. IV. . | 6°19 5 Carpholite H4MnAloSi2016 Velle 2°93 5-55 -_—_—--— — Ss | | Hydrous Silicates-- | | Inesite . 2(Mn,Ca)Si02 + H20. 3:03 6 Ganophyllite . | 6H20.7Mn0.Al203.8SiOz. v. 284 | 4.45 Agnolite H2Mn3(Si03)4 +H20. VI. . | 3:05-3:07 5 Cuap. IT. ] LIST OF MANGANESE MINERALS. 29 TABLE 2—contd. List of known manganese minerals with their chief properties. Crystalline Specific Name. Formula. system. gravity. Hardness. Manganophyl- | Biotite with 5-21% MnO. . V. lite Alurgite . | Amanganese-mica . p We . | 2°83-3 2°25-3 Roscoelite . | Vanadium mica some- Na 2°92-2:94 times with Mn. Caswellite (al- | Ca, Mg, Mn, Fe, Al, silicate oh 3°54 2°5-3 tered mica). Other manga- | nese-micas, Salmite - | Manganesian chloritoid . V or VI. 3°38 ae Masonite = Ditto Z J Ditto . 3°45 — Ottrelite . |Ho(Fe,Mn)AloSi209. Ae . 3-3 6-7 Manganchlorite Silicate of H, Al, Mg, with Ve a Mn. Strigovite . | Ha(Fe,Mn)2\ Fe, Al)2Si2011. a8 3°14 ae Marjatskite . _Manganese-glauconite . aa on ns Bementite . | 2MnSi03.H20 pee se 2-98 ps Caryopilite . | 4Mn0.3Si02.3H20 . - oe 2°83-2°91 | 3-3°5 | | Neotocite . Hydrated silicate of Mn ce | 2°64-2°8 3-4 and Fe. Titano- Silicates— Greenovite . CaTiSiOswithMn V. . | (3°4-3°56) (5-5°5) Neptunite . R’2R” TiSi4012, w th R’= oe 3:25 | 5-6 Na, K, and R’=Fe, Mn; | 30 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ PartTI: TABLE 2—conid. List of known manganese minerals with their chief properties. | | ] se | Crystalline Specific Name. Formula. | yateaie peayity. | Hardness. Hellandite . Cag R’’’3(R”’O)3 (SiO4)4, with R” =Ce, Di,La,Al, | Fe,Mn. | Astrophyllite . | (Na,K}4 (Fe.Mn)4 Ti(Si04)4 EVE, res Soe 3. Lamprophyllite| Contains Na,Fe,Mn,Ti,and |° IV. . | 3-45 S$i0e2. ee Niobates and Tantalate s— Columbite and (Fe,Mn)(Nb,Ta)20¢6. IV. s 53-73 6 Tantalite. Manganocolum-|; MnNb20¢6.MnTa20¢. IV. ' 6°59 bite. Manganotan- MnTa206 4 2 I] DV | 7°30 talite. Hielmite é | Stanno-tantalate of Y, Fe. IV. - 5°82 5 | Mn and Ca. Phosphates and Arsenales— | Berzeliite . _(Ca,Mg,Mn)3As208 E - |..4:07-4:09 5 Soda-berzeliite | (Ca,Mn,Naz2)3As20s. ib : 4°21 | 445 Caryinite . | (Pb,Mn,Ca,Mg)3As208? Vie 4-25-4-29 3-3'5 Triphylite . | Li(Fe,Mn)PO4 - = | nV ° 3°42-3°56 4°5-5 Lithiophilite . | Li(Mn,Fe)PO4 Natrophilite . _NaMnP0O4 - . | TViare *| 3°41 45-5 Graftonite . (Fe,Mn,Ca)3P20s |e ge 3°67 5 Cnap, IT. ] LIST OF MANGANESE: MINFRALS. TABLE 2—contd, 3] List of known manganese minerals with their chief properties. Crystalline 5 a. Name Formul system. Manganapatite | 3Ca3P20s.CaF2 with Mn. a dal. Triplite - | RgP20g.RF2 with R=Fe We and Mn Triploidite . | (Mn,Fe)P20s.(Mn,Fe)(OH)2 V. Sarkinite - | MngAs20g.Mn(OH)s. V. Acid and Basic Phosphates ana Arsenates— Brackebushite | (Pb,Fe,Mn)3V20g.H9 0? V? Chondarsenite | Mn3As90g.3Mn(OH)s. Allactite - | MngAso0g.4Mn(OH)po. V. Synadelphite . 2(Al,Mn)AsO4.Mn(OH)o. V. Flinkite - | MnAsO4.2Mn(OH)pz. Via Hematolite . | (Al,Mn)AsO4.4Mn (OH)g. III. Rhom- bohedral. Arseniopleite . | Hydrated arsenate of Mn, | Ditto? Ca, Pb, Mg and Fe. | Manganostibiite} MnioSb2015? ; j IV.? Hematostibiite | MngS8b2013? Ferrostibian . | Hydrated antimonate of Mn | V.? and Fe. eta Ne | Stibiatil - |Sb205,Mn203,and FeO | Vv? pte Hardness. Te 5 3:44-3°8 vee 3°70 rope 4:17-4:19 45 3 3°83-3°85 AS 3°45-3°50 45 3°87 Pains 3:30-3:40 Me =: by 7 5.65 32 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: TaBLE 2—contd. List of known manganese minerals with their chief properties. | | Crystalline | system gravity. Name. Formula Speanic | Hardness. a os Hydrou = Phos- | phates and Arsenates, elt.— } | | { Purpurite = | (Mn”’’, Fe’’),P,05 + HO. IV.? 3°15 4-4°5 eho ou | | é Dicknsonite 3R,P,03 + HO. with VY, 3°34 | 3-5-4 | R=Mn,Fe,Nag, alsoCa, | Ke, Lig. Fillowite . | 3R3P20s + H20 with ; Va 3°43 | 4°5 R= Mn, Fe,Ca, and Naz. | i ok or Brandtite . | CagMnAs2 Og + 2H20. VI. | 3°67 | Fairfieldite . | CapMnP2Os + 2H20. VI. | 3°07-3°15 3°5 Reddingite . | Mn3P20s3+3H20 IV. 3°10 3-3°5 Hureaulite . | HeMns(POs)s + 4120 v. | 3° 15-3° 20 5 | { | Hemafibrite . | MngAs20s.3Mn(OH): + 2H» IV. | 3°50-3°65 | 3 O. Childrenite . | (Fe,Mn)AI(OH)gP0s+2H20. IV. | 3°i8-3°24 | 4°5-5 Eosphorite . | (Mn,Fe)Al(OH)2P04 + 2H20.| IV. 3°11-3° 15 5 | Antimonates— | | | Atopite . | CagSb207 with often Mn. | I. 5°03 | 5°5-6 Borates— | Sussexite . | H(Mn,Mg,Zn)BO3 IV? 3°42 3 Pinakiolite . | 3MgO.B203 + MnO.Mn20Osz. TV. 3°88 6 a es ea Cuar. II. ] LIST OF MANGANESE MINERALS. 33 TABLE 2—coneld. List of known manganese minerals with their chief properties. roreeee Name. Formula. ee deer ee oe Hardness. 8ulphates— Ky a4 Szmikite . | MnSOz + HeO A . | Amorphous Jal5 15 Tlesite . . | (Mn,Zn,Fe)SO1 +4 He.O0 . Vier ose oo Luckite. . | (Fe,Mn)SO4 + 7H20. a Viet oe | Mallardite . | MnS0O4+7H20 ‘ : V. Apjobnite . | MnAlg(SOa)t + 24H20. | Ve. 1:78 15 Bushmanite . | (Mn,Mg)Alo(SO4)4 + 24H20. | Vitus | Dietrichite . | (Zn,Fe,Mn)Alo(SO4)4 | Wits 2 + 24H20. | Tungstates— | Wolframite . | (Fe,Mn)WO4 | V 7°2-7°5 | 5-5°5 Hiibnerite . | MnW04 | Wo. Boll 7a os 5-5°6 In addition to the minerals mentioned in the foregoing list there are many others that contain manganese in quantities too small to pro- duce any essential change in the characters of the mineral. There are also many minerals containing a considerable proportion of man- ganese, but which have not been sufficiently investigated for their proper position in the above classification to be ascertainable. Of these the following Swedish arsenates and antimonates of manganese, often con- taming other bases such as iron, may be mentioned :—basiliite, chlorarsenian, chondrostibian, elfstorpite, lamprostibian, magnetostibian , melanostibian, retzian, rhodarsenian, sjégrufvite. i D 34 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [-ParTlI: Of the minerals given in the above list about one quarter have been found in India, a few of the occurrences being open to doubt. The following is a list of the manganese minerals yet found in India :— TABLE 3. List of Indian manganese minerals. Oxides— }.5, Pyrophanite ? Dysluite. Manganmagnetite. Hausmannite ? Vredenburgite (3Mng04.2F e203). Sitaparite (9Mn203 4Fe203.MnO9.3C a0). Braunite. Polianite. Pyrolusite. Manganite. Manganates— Hollandite. Psilomelane. Beldongrite (6Mn30;.Fe203.8H20). Wad. Carbonates— Ankerite. Rhodochrosite. Silicates— Blanfordite Manganhedenbergite Brown and yellow pyroxenes (schefferite ? and urbanite ?) Jeffersonite ? Rhodonite Other Mn pyroxenes Winchite Juddite : Yellow and greenish grey amphiboles Manganese-amphibelee. (dannem< rite ?) Spessartite Spandite Grandite (mangan-) Aplome Calderite Withamite Manganepidote ; Manganese-epidotes. Piedmontite Ilvaite ? Carpholite ? Manganophyllite ? Manganese-pyroxenes. nN, ae Manganese-garnets. ‘Cuap. II. ] INDIAN MANGANESE MINERALS, 35 Alurgite ? Other Mn micas Y Manganese- micas. Manganchlorite ? J Ottrelite. Titano-silicates— Greenovite Tscheftkinite. Niobates and tentalates— Columbite. Phosphates— Manganapatite. Triplite. A soda-manganese phosphate. Tungstates— Woltframite. For the non-manganiferous minerals associated with the manganese ores of India see the lists on pages 323 to 325. Some of these are, however, of sufficient interest to be considered here. The following is a list of such minerals :— TABLE 4. List of certain minerals associated with the Indian manganese-ore deposits. Graphite. Magnetite. Chalcopyrite | Martite. Pyrite. Limonite. Pyrrhotite. Gibbsite. Halite. Microcline. Rose quartz. Sapphirine. Amethyst. Lithomarge and Kaolin. Chalcedony and chert. Arsenates Opal. Barytes. Hematite. On comparing the list of Indian manganese minerals with the list of known minerals containing this element it will be seen that in some groups the manganese minerals are adequately represented in India. whilst in other groups there are very few or no Indian representatives. The adequately represented groups are the oxides, manganates, carbonates, silicates, niobates, and tungstates; the sulphides, chlorides, arsenates, antimonates, borates, and sulphates are not represented at all, and the titano-silicates and phosphates only very inadequately. It is in the phosphates, arsenates, and antimonates, that the deficiency of the Indian list is most marked, for, of the total number of 156 minerals given in the list on pages 23 to 33, 33, or nearly a quarter of the whole number, belong to these three allied groups. Considering, I D2 36 MANGANESE DEPOSITS Of INDIA: MINERALOGY. [ Partl: however, that three arsenates, which do not contain manganese, however, and one manganesian phosphate apart from manganapatite, have been found associated with the Indian deposits, it may fairly be expect- ed that future investigation will lead to the discovery of arsenates containing manganese, and of a further number of phosphates. I now propose to give a short account of each of the minerals given in the foregoing lists of Indian minerals. The notes here given are not intended to be exhaustive, but simply to put on record such facts as have been ascertained about the Indian manganese minerals. Many of the identifications are only provisional requiring the test of complete chemical analysis to confirm them. The result of such analysis will doubtless be to show that many of the minerals distinguished with a query mark in the above list, are not identical with the mineral mentioned, but are closely allied, showing small differences owing to isomorphous replacement of one constituent by another. Moreover, it will be noticed that many of the names given in the list are new to science. They are only a few of the many new New species and ‘ oats : : anintea species and varieties of manganese minerals that in all probability exist in the Indian manganese-ore deposits. The following is a list of these new species and varieties :— Vredenburgite Sit’ parite Hollandite Beldongrite Blanfordite Winchite with one, and perhaps all, of the three arsenates found. Some of the manganese-micas will in all probability be found to be new varie- ties, whilst the soda-manganese phosphate is probably a new species. Several other minerals that are probably new, have been noticed in the course of the examination of the specimens collected in the Indian manganese deposits ; hut they are not mentioned here as their charac- ters have not been sufficiently investigated for anything accurate to be stated about them. {t has not yet been found possible to examine carefully some of the well-known minerals like rhodonite and pyrolusite and give figures for their physical characters, such as specific gravity and hardness, based on determinations made on Indian material. Consequently in the case of the more important and commonly occurring minerals, which it is of importance that all engaged in mining manganese-ore should be able to identify, I have taken the figures required from Dana’s System of Mineralogy ; and when reference is made to this work it is always to the 6th edition, unless otherwise stated, CHAPTER III. MINERALOGY —continued. Oxides. Pyrophanite—Dysluite— Manganmagnetite— Hausmannite—Vredenburgite— Sitaparite—Braunite—Polianite—Pyrolusite —Manganite. Pyrophanite. This mineral, of the chemical formula MnTiOs , was originally found at the Harstig manganese mine in Sweden, and has been subsequently recorded as occurring in the Piquiry manganese-ore deposit in Brazil!. In the course of the microscopic examination of thin sections of manganese-silicate-rocks from both the Central Provinces and the Kajlidongri mine, Central India, I have several times noticed a mineral of a blood-red colour, non-pleochroic character, and high index of refraction, that may very well be the mineral pyrophanite. It always occurs in such small quantities, just a flake or two, that it is not possible to isolate any and subject it to chemical tests to confirm this supposition as to its nature. Dysluite. This mineral, which is a zinc-manganese-spinel of the formula (Zn, Fe,Mn)O.(Al,Fe)03,was found in 1897 by Mr. C. 8. Middlemiss of the Geological Survey of India in a felspar-rock containing corundum and sometimes biotite, muscovite, and, in one case, chrysobery. This rock occurs as veins ramifying through the elaeolite-syenite-gneiss between Sivamallai Mill and Karutapallaiyam in the Coimbatore dis- trict. According to Mr. Middlemiss? the dysluite generally occurs in irregular masses or veinlets, but sometimes shows an attempt at the regular spinel form, namely the octahedron. The mineral was determined by H. H. Hayden, to whom it was forwarded from the field, the particular locality for the dysluite thus determined beiny 12 miles S.S.E. of Padiyur. Mr. Hayden reported the mineral to be a zinc-iron- 1 0. A. Derby, Amer. Jour. Sci., XII, p. 21, (1901). 2 Manuscript notes, 38 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Parr raanganese gahnite, the ratio of iron to alumina being 55:47. Besides iron and alumina it was found to contain a good deal of zine and rather less manganese than zinc, with a trace of lime and magnesia, and a very little silica. The specific gravity was found to be 3°95—4:17. The specimens collected by Mr. Middlemiss show masses of the dys- tuite up to 5 inches in length. They are very irregular in shape, some- times shewing a tendency to the octahedral form characteristic of spinels. The immediately associated minerals are white and pink felspar, and biotite. The dysluite itself is black, breaking with a sub- conchoidal fracture, which when fresh shows a somewhat resinous lustre. The mineral scratches quartz. It is very difficult, however, to obtain a reaction for manganese in the ordinary way by fusion with nitre and fusion mixture. The result of two such tests was to lead to the supposition that manganese was not present. On first fusing the uuneral with acid potassium sulphate and then adding nitre and fusion wmuxture a decided manganese reaction was, however, obtained. The streak of the mineral is a somewhat darkish grey. Manganmagnetite. As its name implies manganmagnetite is a variety of magnetite con- taining manganese. Three localities have been so far recorded for this variety. They are :— Locality. Contains :— G. Vester Silfberg, Sweden! . : 3°80 and 627% MnO . . 5064 New Zealand? : : : 4°63% Mn203 and 7:15% MgO 4°67 Kodur, Vizagapatam, Madras3 . 3°00% Mnsg4, 2°52% AleOs 5045 There seems to be some doubt as to which portion of the magnetite molecule contains the manganese. Thus the general formula of man- ganmagnetite may be expressed as (Fe,Mn)O.(Fe,Mn)30, ; or, if allowance be made for the magnesia shown in the New Zealand specimen and the alumina shown in the Kodur specimen, the formula may be stated as follows :—(Fe,Mn,Mg)O.(Fe,Mn,Al)30,. And, if the presence of the alumina be neglected, manganmagnetite may be looked upon as provid- ing the connecting link between magnetite and jacobsite. The Indian 1 Mats Weibull, Min. u. petr. Mittheil., VII, p. 109, (1886). 2 A. H. Chester, Min. Mag., VIII, p. 125, (1889). 3 'T. H. Holland, Rec. Geol. Sur. Ind., XXVI, p. 165, (1893). Cuap. IIL. } MANGANMAGNETITE. 39 specimen investigated by Dr. Holland was strongly magnetic, showing distinct polarity, and otherwise exhibiting the properties of mag- netite. except that its streak was reddish brown instead of black. In my examination of the manganese-ore deposits of the Vizaga* patam district I found that what was apparently manganmagnetite is not at all uncommon. The difficulty is to avoid confounding it with braunite, for, as is explained on another page (63), this mineral is also magnetic, although to a much smaller degree. Both minerals have a lustrous black conchoidal to sub-conchoidal fracture, but braunite usually exhibits a well-marked octahedral cleavage not shown by mangan- magnetite. When in small grains, however. the cleavage of the brau- nite may be difficult to develop. In this case if the mineral be not strongly magnetic it may be taken to be braunite, but it is best to confirm this deduction as to the character of the mineral by making a chemical test. The best is to treat the finely powdered mineral with strong hydrochloric acid. If the mineral be braunite it will leave a residue of gelatinous silica; whilst if it be manganmagnetite it will either dissolve completely, or it will leave only a very small residue due to mechanically included silica, which will not be gelatinous. If the mineral contain only a small amount of manganese, this will of course show that it is not braunite; but the preserce ofa large amount of manganese does not necessarily mean that the mineral is braunite, for there is another magnetic mineral, vredenburgite, that contains a high percentage of this element. The deposit at which I found mangan- magnetite in the greatest abundance is Garbham, but I also found it at Kodur and Avagudem. At Garbhaém it occurs in two ways. One is in a rock composed of manganese-garnet (spandite) with some apatite and a little mica (rich brown), in which the manganmagnetite forms perhaps one-third of the rock. The grains of manganmagnetite are 4 to } inch in diameter. When freshly fractured they are seen to be traversed by rather numerous thin veinlets of psilomelane. To test if the mineral were really manganmagnetite, containing the mangan- ese in combination as a part of the molecule, was therefore a matter of some difficulty. After a lot of trouble some pieces were picked out that had fresh fracture surfaces on every side and showed no trace of the psilomelane veinlets. These were found to give decided reactions for manganese indicating its presence in appreciable quantity, but not in large amount. I must confess that I do not feel absolutely certain that any of the pieces tested were really quite free from psilomelane Occurrence. 40 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [Parr I: veinlets, although as far as I could determine, by careful examination of the specimens to be tested under the microscope, they seemed quite pure. The manganese-ore quarried at Garbham is frequently seen to contain scattered shining specks which at first sight one takes to be braunite. Judging, however, from the magnetism test, these bright specks consist more often of manganmagnetite than of braunite at Garbham, thus accounting for the high percentage of iron found in these ores, At Avagudem a rather common form of ore is one composed of a mixture of psilomelane and pyrolusite with abundant scattered specks of a very magnetic mineral. As at Garbhdm this magnetic mineral is traversed by veinlets of psilomelane, but to a still greater extent. With the greatest difficulty a piece was picked out which seemed to be free from these veinlets ; this gave only a very weak reaction indicat- ing not much more than a trace of manganese. At Kodur the patches and specks of the shining mineral that is so often seen in the mauga- nese-ores are found to consist more often than not of braunite; but sometimes manganmagnetite traversed by psilomelane veinlets is found. As regards the origin of this manganmagnetite it is obvious that when it forms a part of the manganese-ores—which, as is explained on pages 262 to 272, are of secondary origin formed by the chemical alteration, with solution and re-deposition, of various constituents of the rocks of the kodurite series—it must also have been formed during the series of chemical changes by which the ores were formed. In the case of the spandite-rock at Garbhdém in which it occurs it seems, however, possible that it may be an original mineral formed at the same time as the enclosing rock. Microscopic examination does not definitely settle this question. Under the microscope it is seen that the garnet is undoubtedly being replaced by manganese-ore (psilomelane). In places in the rock there are curious rims or borders of garnet to the opaque minerals consisting of manganmagnetite and _psilomelane. Reflected light shows that on one side of the rim is manganmagnetite (grey-black), and on the other psilomelane (dull black) evidently replacing the garnet. The manganmagnetite does not show this evident replace- ment ; hence it seems possible that the original rock was composed mainly of spandite and manganmagnetite and that manganiferous solutions have attacked the rock and replaced the garnet, in some places com- pletely and in some cases only partially, so as to leave an unaltered rim of garnet between the manganmagnetite and the secondarily formed manganese-ore ; whilst the manganmagnetite has escaped alteration, Origin. Cuap. III. | HAUSMANNITE. Al except perhaps along the psilomelane veinlets that often traverse it in all directions. It is not certain, however, that the manganmagnetite is original as here supposed, although this hypothesis seems to suit the evidence. In other parts of India manganmagnetite has not been commonly found. Probably, however, in most of the magnetite-bearing gneisses at Kandri and Mansar, Nagpur district, the supposed magnetite is manganiferous, being usually manganmagnetite, but possibly in some cases braunite. Hausmannite. Up to date no undoubted specimen of hausmannite has been found in India. It is true that Mr. R. B. Foote’ says that the manganese- ore of Ramandrug in the Sandur Hills probably contains its manganese in the form of braunite or hausmannite. But the analysis quoted is sufficient to disprove this ; for the amount of oxygen found is much in excess of that required for either mineral. The specimens collected by Foote are apparently nodules of very impure psilomelane. Several selected specimens of manganese-ores from the Central Provinces were analysed at the Imperial Institute, London ; sometimes the specimens so analysed were found to be simple in composition and composed of one mineral only, but at other times they were found to be mixtures of two or more minerals. In calculating these latter analyses to their mineral composition it was sometimes found that the analysis might be taken as indicating the presence of a certain proportion of hausmannite. Thus alternative arrangements of the analyses of specimens Nos. 995 (Kandri) and 1037 (Mansar) given on pages 868 and 887 are the following :— Specimen No. 995. Specimen No. 1937. (Kandri.) (Mansar.) Apatite . . 4 2 5 (UCTS 0°49 Calcite é - 5 2 0°14 0°14 Braunite (3Mn203.MnSiO3) - OL S85 56°02 Psilomelane (including Fe) - 16°21 22-94 Hausmannite 3 LO 74 20°39 Quartz 1°64 0°36 As205 0°019 0°017 Moisture 0°15 0°10 100°099 100° 457 Oxygen assumed 0°07 se Oxygen surplus 0°30 100°029 100°757 1 Mem. Geol. Sur. Ind., XXV, p. 195, (1895). 42 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [{ Parr: The specimens, however, onlv indicated the presence of two minerals, one of them occurring in small crystalline grains set in a dull matrix of the other (psilomelane). Some of the crystalline grains might have been braunite and some hausmannite ; but as the ore was similar to many other specimens in which calculation did not indicate the presence of hausman- nite, it seemed likely that in these two cases also it was not present. This difficulty was surmounted by assuming that the ferric oxide, included in the psilomelane above as ferric manganate, replaced a part of the MnyO3 of the braunite. It was found possible to take the Mn,03 thus set free into the psilomelane together with the manganese oxide previously calculated as hausmannite ; and thus the mineral com- position was expressed in the terms of two minerals only (neglecting, of course, the traces of quartz, apatite, etc.) as shown on pages 869 and 888. These considerations have nevertheless been introduced here to show the possibility that some of the Central Provinces manga- nese-ores may contain hausmannite, although it has not been yet found possible to prove this in any particular case. Vredenburgite. In two different parts of India, namely Beldongri in the Nagpur district, Central Provinces, and Garividi in the Vizagapatam district, Madras, I have found a mineral that everything agrees in showing is a new species. In colour the mineral is a dark steel-grey exhibiting a bronze tint, especially in the sun. In fact it was this bronzy colour that first drew my attention to the mineral at Beldongri: the difference in tint between this and the ordinary man- ganese-ore of the mine was most marked, the latter, composed of a mixture of braunite and psilomelane, being of a dark steel-grey to black colour, with sometimes a tinge of bluish. The lustre of the mineral is metallic, but not very bright, except on cleavage surfaces. The Garividi specimen shows well-marked cleavage, the nature of which is not obvious, but which I would suggest is parallel either to the isometric octahedron or to the tetragonal pyramid, according to whether the mineral is isometric or tetragonal ; for it wil! probably be found to belong to one of these two systems if specimens be ever found showing recognizable faces. The streak of the mineral is a deep brownish black tending to a deep Characters and cecurrence. Cuap. III. | VREDENBURGITE. 43 chocolate. Its hardness is about 6°5. The most interesting feature of the mineral, however, is its magnetism, for it seems to be just as strongly magnetic as ordinary magnetite ; and indeed, any one picking up a piece of it and testing it with a magnet would say at once that it was mag- netite. That this would be incorrect is shown by the fact that the min- eral contains a high percentage of manganese; in fact, about twice as much of this element as of iron. The mineral is, moreover, distinctly polar, and pieces can be broken off, one end of which will attract one pole of a balanced magnetic needle and repel the other. The coarsely crystallized Garividi specimen is more suitable for this test than the more finely crystalline ore from Beldongri, the latter being of the nature of an aggregate in which the polarity of one individual may neutralize that of another. The Beldongri specimen was found as a thin band, one inch in thickness, intercalated with the other ores in the south-east corner of the quarry, at the point D in Plate 37. This ore is moderately coarsely crystalline, as compared with the usual manganese-ores of this part of India, the individual grains averaging j, to } inch across. This crystal- line aggregate is very compact, and in parts the magnetic mineral tends to get mixed with a little psilomelane. A piece. apparently free from this latter impurity and having a specific gravity of 4°74, was selected for analysis, the latter being carried out at the Imperial Institute. The other specimen was obtained from amongst the heaps of ore from the Garividi deposit. stacked ready for despatch at the station of the same name. In contrast to the Beldongri specimen this is very coarsely crystalline, a piece about three inches in length consisting of only three individuals interlocking one with the other in a sort of poikilitic way. One of these individuals is two inches long. The Garividi specimen, more- over, does not contain any other admixed mineral. The piece of it chosen for analysis had a specific gravity of 4°84, which is somewhat higher than that of the Beldongri specimen. This may mean that there was a little admixed psilomelane in the Beldongri ore, although the way in which the analysis works out to a definite formula does not support this supposition. The slight differences in specific gravity may be due to slight differences in the impurities that each of the specimens probably contain ( see the analyses on the next three pages ). The Garividi specimen was analysed by Messrs. J. & MH. S. Pattinson of Newcastle-on- Tyne. Chemical composition. 44 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part]: The two analyses are given side by side below :— Specimen No. 1080. Specimen No. A. 346. ‘Beldongri.) (Garividi.) Manganese peroxide (MnO2) 5 ZBrOr 24°94 Manganese protoxide (MnO) . 38°24 38°53 Ferric oxide (Fe2O3) . 5 , 28580 31°29 Alumina (Al203) ‘ O - 1°32 2°10 Barvta (BaO) . : : 2 L380) 0°03 Lime (CaO) . ‘ , 5 1°53 0°90 Magnesia (MgO) ; : . 0°99 1°20 Potash (K20) . : : . ee 0°06 Soda (NagO) ‘ : a “die 0°14 Combined silica (SiO2) , 2 O20T 0°20 Free silica (SiO2) : : . 0°86 Nil Sulphur : é 30 0°03 Phosphoric oxide (P205) .. BLOT 0°08 Arsenic oxide (As205) ‘ ORO Nil Cobaltous oxide (CoO) F ute 0°05 Nickelous oxide (NiO) : sn toe Nil Cupric oxide (CuO). : de ts 0°03 Lead oxide (PbO) . , atl ate Nil Zine oxide (ZnO) F : a) tate Nil Titanic oxide (TiOg) . : don 0°14 Chlorine and fluorine . é : : Nil Combined water 5 A seeligoe 0°30 Moisture at 100°C . 5 Ocal 0°20 Carbon dioxide (COg) . ‘ . 0°09 Nil 100 °34 100°17 Manganese : ; : . 44°62 45°62 Tron : ~ . 5 ; 20°19 21°90 Silica (total) ‘ . 3 ee Sy(7/ 0°20 Phosphorus : . 5 . 0°47 0°02 Specifie gravity . - ° we ee 4°84 It is evident from the foregoing analyses that these two specimens represent one and the same mineral composed practically entirely of oxides of manganese and iron; all the other constituents being present in insignificant proportions may be regarded as impurities. The question is then to calculate from these two analyses the formula of the mineral. I will first consider the mineralogical composition of the Beldongri specimen. If the combined silica shown in the analysis be really in this Cuap. III. ] VREDENBURGITE. 45 condition then it will probably be as braunite. On this assumption the analysis can be re-stated as follows :— Apatite 2°47 Calcite 0-20 Braunite 9-12 Hausmannite 53°82 Hematite 28°85 Impurities— Alumina J ISS Pe Baryta 1°30 Lime 0°02 Magnesia 0°99 Combined water 1-32 Quartz 0°86 Arsenic oxide 0°01 Moisture 0°18 100°46 Subtract oxygen assumed 0°12 100°34 On the supposition that the combined silica is present as braunite there is no alternative to the above interpretation of the analysis ; for the Mn30, and Fe:03 are not then present in any simple molecular proportion. But in accordance with this interpretation there should be three constituents easily visible in the hand-specimen, namely brau- nite, hausmannite, and hematite. Examination of the specimen, however, does not reveal the presence of more than one constituent. If, on the other hand, we assume that the combined silica is in combination with some of the impurities, then the analysis can be stated as follows :— Apatite 2°47 Calcite 0-20 Mn304 61°93 Fe203 28°85 Impurities 5°86 Quartz 0°86 As205 0-01 Moisture 0-18 100°36 Subtract oxygen assumed 0°02 46 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part]: Now the Mn304 and FegO3 are present in the molecular proportions of 3 to 2 as shown below :— 61°93 —-— ="2704 = 3 x *09013 229 28°85 —-— ==" 1803, = 2 x 09015 160 Hence we can suppose that they form a mineral of the composition 3Mn304.2Fe9O03, rather than a mixture of hausmannite and hematite. Taking now the case of the Garividi analysis, all the constituents may be regarded as impurities accidentally picked up during the formation of the mineral, except the oxides of manganese and iron, to which, as in the case of the Beldongri specimen, we will confine our attention. The oxides of manganese given in the analysis on page 44 correspond to :— Manganese : ; : . 45°61] Oxygen. . - 3 lr 86) Now 45°61 manganese requires 17°70 oxygen for the formation of Mn304, so that here also it seems almost certain that the manganese is present in the form of the proto-sesquioxide. Again the question arises as to whether this Mng04 is to be regarded as hausmannite in mecha- nical admixture with the Fe ,OQs in the form of hematite, or whether the oxides of manganese and iron are in combination as some definite molecule with a definite molecular formula. Calculation shows that the relation between the MngQO,4 and the Fe:Qx is not so exact as in the case of the Beldongri specimen. Neglecting all the constituents except the oxides of manganese and iron the composition of the mineral is :— Mn304 _ —yw . : , 63°31 FegO3 ; ¢ 5 ‘ = ol29 Surplus oxygen " 5 ee PING 94°76 Now to satisfy the formula 3Mn304.2Fe.03, 63°31 Mng04 requires 29°49 Fe Os, whilst 31°29 is available; that is, there is a sur- plus of 1°80 Fe 03. This is not excessive and may be taken as showing that the Garividi specimen has the same formula as the Beldongri CHap. III. | VREDENBURGITE. 47 specimen, the extra Fe,O, being regarded as a further portion of the impurities. On the evidence of the foregoing calculations it might then be con- sidered as fairly certain that the formula of this mineral is really 3Mn304. 2Fe,03. At first sight, however, there might seem to be an objection to this formula in the fact that the mineral is so strongly magnetic that the iron must be supposed to be present as Fe304 rather than as Fe 903. But this is not a real objection, because there are several minerals exhibiting magnetic properties—usually it is true, to a much smaller degree than magnetite—that do not contain their iron in the form of Fe304. Thus pyrrhotite or magnetic pyrites, a sulphide of the formula Fej)Sj9, is often strongly magnetic. Ilmenite is often slightly magnetic. Its formula may be written either as FeTiOs, as (Fe,Ti)gO3, or as mFeTiOg.nFe,03. Whichever interpretation be the correct it is seen that the iron is in the form of either FeO or Fe,03. Since hematite (Fe203) is usually non-magnetic, it seems as if the magnetism of ilmenite must be due to the presence in it of titanium and not iron. In the same way all the Indian braunites are more or less magnetic. Although the formula of braunite is open to some doubt, as is shown in the section dealing with this mineral, yet no interpretation of it shows the presence of an R304 group. Now the Indian braunites usually contain an appre- ciable proportion of iron replacing a part of the manganese. Such iron must, therefore, be in the form either of Fe,Os or, less likely, of FeO. It so happens, however, that some braunites are very low in their iron percentage, and yet are still magnetic. Hence we must suppose that, as in the case of the ilmenite the magnetic properties of the mineral are due to the titanium rather than to the iron, so in the case of braunite the magnetism is due,to the manganese rather than to the iron. Hence in the case of the mineral under consideration it does not necessarily follow that its magnetic properties are due to the iron, even though it is present in large amount. The manganese may be the cause of the magnetism; but considering the strength of this property it seems more probable that the iron has something to do with the magnetism. It may be that this particular proportion of manganese and iron oxides gives rise to the magnetism. It will be seen from the foregoing that even if the magnetism be entirely due to the presence of the iron, it does not follow that it is present in the form of FegQ4. It will be interesting, however, to see if the analysis can be interpreted on the supposition that the iron is present in the FeO, condition. 48 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ PartI: If in each of the analyses the iron be supposed to be present in the form of Fe304 and the manganese in the form of MngOQs, then the amounts of these oxides work out as follows :— Beldongri. Garividi. Mn203 2 ; : : 64°08 65°51 Feg04 5 5 ‘ : 27°89 30°25 91°97 95°76 Subtract O assumed . : iter 1°00 90°76 94°76 With this arrangement the formula works out as corresponding in both cases very closely to 10Mn903.3Fe304. Since, however, the error in the oxygen is on this interpretation so large, it would be better to suppose that the manganese is not all in the form of MngOs, but that a portion of it is in the R304 group isomorphously replacing a portion of the iron. On this supposition and using the oxygen, manganese, and iron, as actually determined, as the basis of calculation, the composition works out as follows :— Beldongri. Garividi. Mn203 =C«j . : < 28°23 35°89 Mng304 ; 4 : 4 34°64 28°62 Fe304 : : : : 27°89 30°25 90°76 94°76 The molecular proportions of the three oxides then work out as follows :— Beldongri. Mn203 : : 5 ~ = °1787 2 x 0800 Mng04 ; p f 5 = US) Soe — ox OOUr Fe304 : : : » = +1202 Garividi. Mn203 3 - A P77) — ee Ono Mn304 5 : . = 1249 ) 2553 = 8*x °0319 Feg04 ‘ - _ = -1304 5 These correspond respectively to the formule— Beldongri . y - 2Mn203.3(Mn,Fe)304 Garividi $ ; . 7Mn203.8(Mn,Fe)304 We have thus arrived at the following alternative formule :— Beldongri. Garividi. 3Mn304.2Fe203 3Mn304.2Fe203 10Mn203.3Fe304 10Mn903.3Fe304 2Mn203.3(Mn,Fe)304 | 7Mn203.8(Mn,Fe)304 Cuap. III. ] SITAPARITE. 49 Of these formule the simplest is the first, to which the analyses correspond more nearly than to any other, if a little of the iron be regarded as impurity in the Garividi specimen. The second is the least probable interpretation as it is then necessary to assume errors of 1°00 and 1°21, respectively. in the determination of the oxygen. Which- ever be the correct formula there is no doubt that this mineral is a new mineral species. I propose to call it vredenburgite after my colleague Mr. E. W. Vredenburg, under whom I spent my first field season in India and first came in contact with deposits of manganese-ore. Its main interest lies in its combination of strongly magnetic characters with a high percentage of manganese. In consequence of the former property it is liable to be mistaken for magnetite if—as is only natural, considering that up to the present the only black strongly magnetic mineral’ that has been recognised is magnetite—its chemical character be not determined. Whilst on account of its well-marked cleavage and the fact that it is found in manganese deposits, it is liable to be mistaken for braunite, unless its magnetic characters be examined. The fact that it dissolves up practically completely in acid, without leaving a residue of silica, serves to distinguish it from braunite; so also does its duller lustre on cleavage surfaces and its curious bronzy lustre in the sun. Otherwise, in hardness, cleavage, and specific gravity, there is a remarkable simi- larity between these two minerals Sitaparite. At Sitapar in the Chhindwara district, Central Provinces, there occurs amongst the interesting association of minerals forming the ores of this place a dark bronze-coloured mineral that looks very like the one I have called vredenburgite. It is, however, distinguished from the latter by the fact that it is only slightly magnetic, vredenburgite being about as magnetic as magnetite. The actual colour of the mineral may be de- scribed as dark bronze-grey, the bronze tint being especially well seen in the sun. It is, moreover, sufficiently well marked for the mineral to be at once distinguished from its associates in the ores in which it occurs. The streak is black, the lustre metallic. The mineral is brittle and tends te break along almost perfect cleavage planes, which may be octahedral. The hardness of the mineral is about the same as tnat of quartz, The specific gravity seems to be somewhat variable, three pieces showing Characters. 1 Excluding native elements. I ze 50 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Parr values for this constant of 4°93, 4°99, and 5°09, the mean value being 5°00. An analysis of this mineral was made by Mr. T. R. Blyth, of the Geological Survey of India, on a piece having a specific gravity of 4°93. The result is as Chemical composition. follows :— Specimen No. 843 A, Manganese peroxide 3 = 36°79 Manganese protoxide : -| 26°89 Ferric oxide . C ; au) 2c 00 Alumina : - : : 1°02 Baryta . : : : ; 0°10 Lime . c : : : 6°14 Magnesia : : 5 : 1°02 Silica . : . ; : OAT) Moisture at 100° C. . : : 0-09 100.°82 Manganese . A 3 c 44°09 Iron. : : 5 - 19°32 Specific gravity . - : 4°93 Below are compared the figures for the oxides of manganese and iron, and metallic manganese and iron, with those for the two specimens of vredenburgite of which the full analyses are given on page 44 :— Beldongri. Garividi. Sitapar. MnO2 ; ; 3 tu Zowon 24°94 36°79 MnO > ‘i : . 38°24 38°53 26°89 FegQ3 . : . . 28°85 31°29 27°60 90°76 94°76 91°28 Manganese. . . . 44°62 45°62 44°09 Iron . : : : . 2019 21°90 19°32 It will be seen that there is a striking resemblance between the Sitapar mineral and the two specimens of vredenburgite, particularly in the amounts of ferric oxide, manganese, and iron. The difference between the two minerals lies, however, in the state of oxidation of the manganese. Whilst vredenburgite contains considerably more MnO than MnOg, the relative amounts of these two oxides are reversed in the Sitapér mineral. Consequently the Sitapar mineral cannot be made to conform to the formula of vredenburgite. In the case of vreden- burgite I regarded the constituents other than the above as impurities, becanse none of them was present in any important quantity, nor had Cuap. II1.] SITAPARITE. 5] any important effect on the formula. Their total amount was, however, not so smali, being about 9 per cent. in the Beldongri specimen and 5 per cent. in the Garividi specimen. In the preseat case one of the constituents other than oxides of man- ganese and iron is present in sufficient quaatity for it to be necessary to take it into account in calculating the formula. This is the lime ; and in investigating the significance of this constituent in the for- mula I have grouped with it the oxides of barium and magnesium. Below I give the figures for the molecular ratio of each constituent :— MnOe =f 0 -4230 =—10 x °0422 MnO ee — 0°3787 =9 x ‘0421 i 27-6 HesO ge pation BT Pe C5 160 Cag) =e k= grinds! © 5 96 { : 02 MgO) = ones «| = 01355 = 3. x 0252 40 °36 | 0-10 B —— = 0:0006 a0 153-4 . J ‘i Reve anise: Si0dg = SRR 0-0194 = 2 x 0485 In the last line I have also given the molecular ratio for the sihca to show that it is present in too small a quantity to be taken into account in working out the formula of the minezal. It will be seen, however, that the CaO, MgO and BaO taken together are molecularly nearly as important as the ferric oxide. According to the above the formula is as follows :— 10Mn02.9Mn0.4Fe203.3(Ca,Mg, Ba)O. Leaving out the MgO and BaO and grouping together the oxides of manganese this can be stated more simply as follows :— 9Mn203.4Fe203.Mn02.3Ca0. 52 MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ Parr I: From this it might be thought that the mineral is only to be regarded as a variety of the very rare sort of braunite having the simple formula Mn203, in which a portion of the manganese is replaced by iron, the one molecule of MnO,y and the 3 of CaO being impurities. The quan- tity of the latter seems to me to be too large for it to be treated as an impurity, especially as the specimen analysed was a portion of one crystal only and was apparently quite pure and free from adventitious mat- ter. Apart from the presence of the lime and excess MnOo, the bronze tint of the mineral is sufficient to show that the mineral is not a variety of any sort of braunite ; for the latter usually possesses a rich black colour, and is, moreover, present in the same ore, as a mineral of very different appearance. Another alternative is to regard the iron as being present in the form of Fe,;0,. Under this supposition the formula of the mineral works out as 6Mn304.4Fe304.12Mn05.5CaO. It does not, even in this form, show any close relationship in formula to any other mineral. Hence it seems better to accept the simpler formula 9Mn903,4Fe903.Mn09.3CaO, as the best expression of the compo- sition of this mineral, and to regard it as a new species. As the locality where it is found contains such a number of interesting minerals I think this mineral can be most appropriately called sitaparite.' I do not at present know what is the meaning of the variable specific gravity noted above. It may correspond to a variation in the composition of the mineral in which one constituent is replaced by another without altering the general formula of the mineral. Further work on the mineral, when a larger number of specimens have been analysed, may result in a modification of the formula of the mineral as given above, but it will aot alter the fact that the mineral has a individuality that enables it to be distinguished from all other manganese minerals. The only two minerals to which it bears any resemblance are manganmagnetite and vredenburgite. It is distinguished from the former by its bronze tint and weak magnetism; and from the latter, which it resembles in its bronze tint, by its weak magnetism. Braunite. Of all the manganese-ores found in India braunite is, with the exception of psilomelane, the most important. The existence of this 1 To be pronounced with the accent on the third syllable’ in which the ‘a’ is like the ‘a’ in‘ park’. The ‘i’ in ‘Sita’ is pronounced like ‘ ee’. Cuap. ITT.] BRAUNITE. 53 mineral in India was first recognized by Dr. A. J. Scott in 18521, who analysed two specimens said to have come from Vizianagram and Bimlipatam, respectively. As manganese-ores are not known to exist at either of these towns, the probability is that the specimens were obtained from the manganiferous area of the district in which these two places are situated. From the account given of the characters of the ores examined it is evident that they consisted of mixtures of braunite and psilomelane. The analyses of these two specimens are given in the paper cited, and Scott remarks with regard to the Vizianagram ore that its analysis agrees most nearly with that of Damour’s Marcellin, an impure braunite from St. Marcel in Piedmont. Two years later Mr. Marcadieu recorded the discovery near Dharmsdla in the Punjab (see page 1156) of a mineral that ‘approaches by its composition and crystalline form to marcelline’. The crystals he describes as octahedral with a square basis.2 Since then it has been found to occur in great abundance in various parts of India. I do not intend to give here a detailed account of all the occurrences of this ore, but will only refer to the most interesting and important of them. An account of all that was know» about Indian braunite up to the year 1887 will, however, be found on pages 55 to 57 of Mallet’s ‘ Mineralogy ’. As far as my own experience goes braunite is found in India only in association with the manganese-ore deposits that Occurrence. occur in the Archean rocks. And, as is described in the chapters dealing with the geology of these deposits, there are two chief groups of these deposits. The braunite that occurs in the deposits formed by the chemical alteration of the rocks of the kodurite series in Vizagapatam has, if my view of the origin of the ores of this area be correct, been formed during the chemical changes by which the manganese-ores were derived from the manganese-sili- cate minerals. In these deposits, however, braunite is not nearly so abundant as in the deposits occurring in the rocks of Dharwar age in the Central Provinces, Central India, and Naérukot, 7.e., in association with the gondite series. In these latter deposits I suppose that a portion of the manganese-ores has been formed direct by the metamorphism of the original manganiferous sediments, whilst another portion of the ores has been formed by the chemical alteration of the manganese silicates that were formed by the metamorphism of the more impure of the 1 Edin. New Phil. Jour., LIII, pp. 277-279. 2 Selections, Public Correspondence, Punjab Administration, II, No. vii, p. 4. 54 MANGANESE DEPOSITS OF INDIA : MINERALOGY. [Part lI: original manganiferous sediments. It is probable, as far as can be judged from the careful study of the specimens collected, that braun- ite, which is often the predominant mineral in these deposits, has been formed in both ways. At one locality in the Central Provinces, namely Kacharwahi in the Nagpur district, braunite crystals are found in abundance in an albite-zock that is probably intrusive in the ore-body. Hence we see that the Indian braunite has been formed in three distinct ways, as foliows :— 1. By crystallization from an igneous intrusive ; at Kacharwahi. 2. By the metamorphism of manganiferous sediments ; in the Cen- tral Provinces, Central India (Jhabua), and Narukot. 3. During the chemical alteration under the influence of waters— probably heated, and containing chemical reagents and solvents—of manganese silicates, sach as manganese garnets and manganese-pyroxenes, these silicates being contained (a) in the igneous rocks of the kodurite series in Vizagapatam, and (0) in the metamorphic rocks of the gondite series in the Central Provinces, Central India, and possibly Narukot. There is no certain evidence of the occurrence of this mineral in any other areas in India, or in rocks of any other age, than those men- tioned above. It must be mentioned, however, that minute specks of a crystalline mineral sometimes showing octahedral faces are occa- sionally seen sparsely distributed in the ores of other areas, especially the Sandur Hills. This mineral may also be braunite, but has not been investigated, and is perhaps more likely to be magnetite. In view of the enormous quantities of this mineral that exist. in India it might be thought that abundance of material would now be available for the convenient study of the crystallographic characters of this mineral. Such, however, is not the case, the mineral being only rarely found in measurable crystals. In the Vizagapatam deposits it usually occurs as specks and patches of irregular shape embedded in a matrix of psilomelane. In fact I have not cbtained from this area a single specimen showing crystal faces. In the deposits of the Central Provinces, Jhdbua, and Ndérukot, the mineral usually occurs in one of two forms. One of these is a finely granular aggregate in which all the grains are braunite pressed one against the other, but showing a tendency to a general octahedral shape. The other is a rock composed of a mixture of braunite and psilomelane, little granules of the braunite being set in a matrix of psilomelane. ( Plate 1 shows a photo- micrograpi of a polished and etched slice of such ore.) ‘The proportions GEOLOGICAL SURVEY OF INDIA. Memoirs, Vol. XXXVII, Pl.1 L. L. Fermor, Photomicrograph. Bemtrose, Collo., Derby. x 16. Photomicrograph by reflected light of a polished and etched slice of manganese-ore from Ramdongri, Nagpur district, C. P. The dark part is braunite (crystalline), and the light part, or matrix in which the braunite is set, is psilomelane. Cuap. III. | BRAUNITE. 55 between the two are subject to great variation, and such ore can grade into psilomelane on the one hand and into the granular aggregate of braunite mentioned above on the other hand. In this mixture the braunite individuals sometimes become quite large, as much as } to 1 inch across ; but even then the development of crystal faces is prevented by the cement of psilomelane, or by the braunite crystals either interlocking with or pressing against one another. In one case, namely at Lohdongri in the Nagpur district, there are spaces between the layers of ore in which the braunite has had the opportunity of developing crystal faces (for an account of the exact mode of occurrence see page 917) ; whilst at Kajlidongri also, crystals with well developed faces have been obtained by Mr. H. J. Winch, presumably from some cavity in the ore; a single specimen was also obtained by the late Mr. A. M. Gow Smith at Kodegaon in the Nagpur district. The best locality for crystals is, however, Kach- arwahi, where they are to be found in abundance in an albite-rock, fre- quently containing blanfordit2 and sometimes quartz, and which as men- tioned above is intrusive in the ore-body. One individual showing crystal faces was also noticed amongst the ores from Sitapdr. The total number of specimens from these five localities is considerable, as also is the number of faces represented. I have not yet been able to carry out a detailed crystallographic EN Yea investigation of all the forms represented, so that characters: value of | 1 do not propose to give here details of the angular the fundamental measurements made up to date. The angle pp’ angle pp’. between the faces of the unit pyramid was measured on a considerable number of crystals. For this purpose the crystals from Kajlidongri were found to be the best fitted, since they give the brightest reflections. The mean of the value for this angle determined over 12 edges measured on 6 crystals was found to be 70° 22’, the range in angles being from 70° 17’ to 70° 273’. Inthe majority of the Kachar- wahi specimens the edges are rounded, with a corresponding corrosion of the faces, so that good reflections are difficult to obtain. Hence of a number of measurements made only 5 were considered to be worth taking into account. These were made on five edges distributed over four crystals, The values ranged from 70° 134’ to 70° 253’, the mean being 70° 183’. Ofthe Lohdongri braunite only two suitable specimens were available. From these only one measurement was of any value, being 79° 25’. The Kodegdon and Sitapdér specimens were not suitable for goniometric measurement. The mean ofall the values given above is 56 MANGANESE-ORE DEPOSITS OF INDIA: MINERALOGY. [Parr I: 70° 21’, Now the following values for this angle pp’ have been deter. mined by various observers :— Author. | Locality. Value. 2 eee JR 3 Gee ae Haidinger 1 : : . | St. Marcel, Piedmont : Sell iKO 7h Des Cloizeaux 2 . : . Ditto : : Sule Opes Vom Rath? . : : Ditto Z : .| 70° 8’ and 70° 13’ Flink4 : : . Langban, Sweden . : a dOraLos AEN SPIES TTS ES EE FT It will be seen that the mean of my determinations agrees with Flink’s value rather than those of other observers ; and as the difference from that of Flink is only 2’, I shall accept his value for the present. I do not, however, think that the determinations of the other observers are to be regarded as incorrect ; indeed I think it probable that there is a small variation in the value of this angle from crystal to crystal, corre- sponding with the variation in composition to be noted later; and pro- bably the differenve between the values of this angle on the Kajlidongri and Kacharwahi braunites and on the foreign braunites is due to some difference between the composition of the crystals from the different places. Itis further probable that even at one locality there is a variation from specimen tospecimen. Thus of the crystals from Kajlidongri one gave the following four values for pp’ :—70° 27’, 274’, 26’, and 17’, the images for the first three angles being very good and one of those for the fourth edge poor; whilst another crystal from the same mine gave the following values, of which the first three are from very good reflec- tions :—70° 18’, 183’, 18’, and 203’. Hence it seems probable that the composition of these two specimens must be slightly different, corre- sponding to an angle of 70° 27’ in one case and 70° 18’ in the other. From the value 70° 19’ Flink calculates the value ee of the verti- of ¢, the vertical crystallographic axis, to be 0°9924, an in the paper cited above, and 0°99218 in a later paper.o From this value 70° 19’, however, I calculate the value to be 0°99220, giving the value for c2, so useful in calculating the angles between the faces of the crystals, as 0:98447. The habits of the crystals from the different localities vary consider- 1 Trans. Roy. Soc. Edinb., XI, pp. 1382-134, (1831). 2 Annales des Mines, 4mo. Ser., I, p- 423, (1842). 8 Sitzungsb.d. nied. Gesells. Bonn, p. 224, Dec. 1882. 4 Bihang. k. Sv. Vet. Akad. Handl., XIII, Part II, No. 7, p- 37, (1888). 5 Op. cit., XVI, Part II, No. 4, p. 7, (1890). Cuap. III. ] BRAUNITE. 57 ably. Thus the prevailing form at Kajlidongri is the combination _..,.... of the fundamental pyramid p or (111) with the Baia ard ditetragonal pyramid « or (421), see fig. 1. Some- times thin bevelling edges of r or (865) are present, Fig. 1.—Braunite, Kajlidongri. Fra. 2.—Braunite, Kajlidongri. as in fig. 2, and very rarely little faces of the prism of the first order m or (110) shown in the same figure. Very rarely these crystals are truncated by the basal plane e or (001). Simple pyramids or octahedra are very rare and no twins have yet been observed. At Kacharwdhi, on the other hand, simple tetragonal pyramids or Th ene octahedra are common, although they often show e acharwanhtl é ; crystals. the basal plane c as well, as in fig. 3. Frequently the octahedral crystals are rendered more com- plicated by the presence of faces of the ditetragonal pyramid y or (423), as shown in fig. 4. 5 Fic. 3.—Braunite, Kacharwahi. Fic. 4.—Braunite, Kacharwahi. 58 MANGANESE DEPOSITS OF INDIA : MINERALOGY. | Parr[: The ditetragonal pyramid z is also fairly often present, one of its commonest combinations being with p, as in fig. 1; but as the angles are somewhat rounded these crystals tend to be barrel-shaped in aspect. Fig. 5 shows a combination of p, z,y,m,andc, this being the only example of the face m found on the crystals from this locality. Fic. 5.—Braunite, Kacharwahi. Fic. 6.—Braunite twin, Kacharwahi. Another crystal, which, if perfect, would be some 4 inches long, shows one face of r, in addition to the forms p and x shown in fig. 1. Besides these simple crystals, iwins are very abundant in this deposit. One of the commonest is a simple contact twin on the plane e or (101), shown in fig. 6. Since the fun- damental pyramid of braunite approaches very closely to the cubic octahedron, the edges AB and BC of fig. 6, instead of showing a Twins. Tic. 8.—Braunite twin, Kacharwahi. Fic. 7.—Braunite twin, Kacharwahi. Cuap. IIT. ] BRAUNITE. 59 re-entrant angle, seem to be in a perfectly straight line ; whilst the two adjacent faces ABO and BCO are almost in the same plane, so that they seem to reflect light almost simultaneously, and, as viewed on the goniometer, give images that are only a few minutes distant from each other. Consequently, when the pyramid is not truncated by the basal plane in the way shown in fig. 6, the fact that the crystal is a twin is very apt to be overlooked. If, however, the crystal is cleaned its twinned nature is revealed by the existence on the apparently continuous plane AOC of the line BO. When the basal plane is present, the twinned character of the crystal is rendered obvious by the juxtaposition of the two planes ¢ and ¢. These contact twins also show the faces y modifying p. In addition to the contact twins, interpenetration twins are common. One of these, composed of ¢, p, and «, 1s shown in fig. 7, the presence of x giving rise to re-entrant angles. Interpenetration twins of the form c, p, and y, have also been found, as in fig, 8. One other habit that requires notice is that illustrated in fig. 9, in which the forms represented are p, x, y, and the new face g. The latter is, of course, a pyramid of the second order, steeper than the pyramid of the second order, e or (101), mentioned above as a twinning plane, but to be noticed below as a A new form. Fic. 9.—Braunite, Kacharwahi. Fig. 10.—Braunite, Lohdongri. face actually observed. The specimen from which this figure was drawn was a minute chip showing only one corner of the crystal with two p 60 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Parr [: faces, two y faces, one x face, and one g face. The formula of the face g is completely determined as (201) by the fact that it is situated in the two zones whose symbols are [112] and [112]. The angular measure- ments confirm the symbol (201). For the Lohdongri crystals I am mainly dependent on the notes ais Londokea eee I made when at Lohdongri, where Mr. E. L. Young tals. * has a fine set of specimens of braunite from this deposit. One of these, kindly lent to me by Mr. Young, 1s shown in Plate 2, from which it will be seen what a size the Indian braunite crystals sometimes attain. ‘This specimen shows the simple octahedron or pyramid, p, one of which measures 3 inches along an edge between two pyramid faces ; one of the pyramids is truncated by c. Of some small crystals presented by Mr. W. H. Clark of Kémthi, three show the simple octahedron, whilst one is a contact twin on e, of the habit represented in fig. 1, the forms present being p and z. Of the specimens | examined at Lohdongri, one is represented in fig. 10, being a combination of p and m, with the prism of the second order, a or (109), which I have not seen on any other Indian specimen. Another crystal showed a combination of c, p, z, and the rare face e or (101), which, although commonly found as a twinning plane, is very rarely seen as a face on braunite crystals. Other crystals show combinations of c, p, and y, similar to fig. 4, but with c and y more prominently developed relatively to p. One octahedron was elongated along a horizontal axis bisecting the angle between the two lateral axes of braunite, so that the trun- cating basal plane was drawn out into a long rectangular face. From Kodegéon only one crystal has been obtained. This is a ‘ fine specimen, which if whole would be some 2 to 3 The Kodegaon crys- . 5 ; tal. Fe inches across. It is of great interest on account of the faces shown, being a combination of p, y, and the rare form e, all well developed, with in addition a new form z. This is a ditetragonal pyramid that is less steep than e, and consequently forms the top end of the crystal. Only two faces are shown, and on account of the large size of the specimen, so that it cannot be accurately measured on the reflecting goniometer, and the fact that the new face cannot be referred to two intersecting zones, or even to one zone with two known faces, I have not yet been able to determine for certain what is the symbol of the face. It may be either (425) or (849); the measurements agree more closely with (425) than with the other form. As this form has not yet been certainly determined I have not figured it here. A new form. GEOLOGICAL SURVEY OF INDIA. Memoirs, Vol. XXXVII, Pl. 2. Photo. by H. B. W. Garrick, Calcutta Phototype Co. MASS OF BRAUNITE CRYSTALS FROM LOHDONGRI, NAGPUR DISTRICT, C. P. 4 NATURAL SIZE. Cuap. IIT. ] BRAUNITE. 61 From the above it will be seen that the Indian braunites have yielded three new forms, designated by the letters g, z, and r. The face g, or (201), found only on one Kachar- wahi specimen, I have already noticed. The face » is found quite commonly on the Kajlidongri specimens. Owing to the extreme narrow- ness of the edges representing this form, the images it gives are extremely faint and usually very blurred. Consequently it is not certain that it is always the same face that is present. The most likely one, however, seems to be that having the formula (865); sometimes, however, there is more than one of these faces between p and x; one of these others may then correspond to (976). One face in the same position has also been noticed on a specimen of Kacharwahi braunite. This was too dull for measurement, but is probably the same as that found on the Kajlidongri mineral. The third new face z, of the probable formula (425), is noticed above. Three new forms. Some of the faces of the Indian braunite crystals often exhibit stria- tions. The commonest are horizontal ones, some- times taking the form of deep grooves, on the taces of x, parallel to the intersection of each face of this form with the corresponding face on the opposite side of the plane containing the lateral axes; for example, parallel to the intersection of 421 and 421 More rarely the faces of the form y are striated parallel to their intersections with the faces of the form p. Thus 423 would be striated parallel to its intersection with 111, and 423 to its intersection with 1]1. Further, on the Kajlidongri specimens the pyramid faces, p, are often not perfectly plane, but marked with two sets of crossing striations parallel to the intersections of each p face with the two under- lying « faces, the crystal being placed in the position shown in fig. 1. Striations. In size the crystals of Kacharwdhi and Lohdongri range from a diameter of a small fraction of an inch, to 2, 3, or even 4, inches across. The one crystal from Kode- gion would be 2 to 3 inches in diameter if whole. The Kajlidongri erystals seldom reach such dimensions, being usually about 4 to } inch long ; but some would be, if whole, 1 to 14 inches long. (Plate 2) Siz? of crystals. From the foregoing it will be seen that 10 forms have been recog- , nized on the Indian braunites. The following List of forms on . Sa e Indian and foreign table shows their symbols, and distribution amongst braunites, the different localities :— 62 MANGANESE DEPOSITS OF INDIA : MINERALOGY. [Part lI: TABLE 5D. Faces observed on Indian braunites. Worms. Kajlidon- | Kachar- eri. a ahs | Modeg seu: Lohdongri. Sitapar. cor (001) F ; c c Be c c a or (100) ; : - sc oe nic a m or (110) : . 2 m m Esa m 2! or (101) . ; 3 ex as tw. pl. e e(andas her tw. pl). p_or (111) p : xz 2or (421) x e : p yor (423) 1 5¢ z or (425)? . : 5 Tie is 4 4c gor (201) - s 5 ee q ee r or (S65) : : onl r r 5 es me a ne ere Of the above, the first seven forms have also been found on foreign braunites. In addition the following five forms have been recorded by Flink 4 as occurring on the braunite of Langban :— o = (304); 2 = (401); 4 = (212); s = (645); ¢ = (524); whilst the form s = (221), designated g by Flink, was found by Haidinger on the braunite of Elgersburg in Thuringia. Hence the total number of forms so far recognized on crystals of braunite is 16. Their distribution on the crystals of different localities is shown in the following table :— TABLE 6. Faces observed on foreign braunites. Locality. ce ait Forms present. India : i : : ; ‘ : ; a 10 Given above. Langban, Sweden 5 ‘ f ; : : =| 12 c, a, m, e, 0,1, Ps Ly Ys 85 t, te St. Marcel, Piedmont 6 a ‘ ‘ ; Sal 2 p,«;ande as twin plane. Elgersburg, Thuringia 7 : : - ; F 2 Pp, 8 (9)- Wunsiedel, Bayreuth, Bavaria 8 : : ; : 3 c, p, 8 (9). Windgallen, Uri, Switzerland 9% 3 a, Mm, e. eee en ee ee ee ee eee 1 Called n by Flink. 2 Called k by Flink. 3 Called h by Flink. Loc. cit., pp. 5 and 6, (1890). Flink, loc. cit. 6 Haidinger, Des Cloizeaux, and Vom Rath, /oc. cit. 7 Haidinger, loc. cit. 8 Haidinger, loc. tit. With regard to this locality Haidinger remarks that it is exceed- ingly problematical, and that the specimens resemble those of Elgersburg ; and as no specimens have since been recorded from Wunsiedel, these crystals are probably correctly regarded as derived from the Thuringian locality. 9 C. Schmidt, Zeit. Kryst., XI, p. 603, (1886). Op Cuap. III. ] BRAUNITE. 63 According to Dana’s ‘System of Mineralogy’ braunite shows the following characters :—Cleavage: perfect parallel to the faces of the tetragonal pyramid or octahedron. Fracture uneven to sub-conchoidal. Brittle. H.= 6—65. Ga=4:75—4:82. Lustre submetallic. Colour dark brownish black to steel-grey. Streak same. In most respects the Indian braunites agree with the above. Thus, of the three specimens of braunite of which the analyses are given below, two have a specific gravity of 4°79, whilst the third, which con- tains a considerable quantity of magnesia and is therefore not typical, lies outside the limits given above, having G. =4:70. On crystal faces the lustre can perhaps be correctly designated sub-metallic, but on fresh cleavage surfaces it is brilliantly metallic. The colour of the Indian braunites is never brownish black as far as I have seen, but may be either a pure black or a deep steel-grey. Physical characters of braunite. A feature of this mineral, which is not, however, mentioned in the diagnosis given by Dana, is that the mineral is invariably slightly magnetic. The strength of this property varies greatly, and is sometimes quite strong. If some of the tiny grains composing the braunite-psilomelane mixtures of the Central Provinces be detached from the ore they can almost invari- ably be picked up by a small hand magnet, or at least made to move slightly under its influence. The magnetic properties of the Indian braunites might be thought to be due to their contents of iron. This, however, does not necessarily follow; for the specimen (16°815) of which the analysis is given on page 68, though not corresponding very closely in composition to the theoretical braunite (in fact I have separated it as a variety of this mineral), contains only a very small quantity of ferric oxide compared with some of the Indian braunites. It is, however, just as strongly magnetic. Magnetic characters. The question as to the chemical composition of braunite has been the subject of repeated discussion, and it cannot be said that even now this point has been satis- factorily settled. The mineral was first distinguished as a separate species by Haidinger in 1826.’ In this paper he calls the mineral ‘ brachytypous manganese-ore ’ and notices specimens from botk Elgersburg in Thuringia and St. Marcel in Piedmont. In 1827 he read a Composition of braunite. 1 Bdin. Jour. Sei., 1V, p. 48 (Dana); translated into German in Pogg. Annalen, VII, p. 234, (1826). 64 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ ParTI: paper before the Royal Society of Edinburgh’, in which he gives a somewhat fuller account of the mineral and designates it ‘ braunite’ after Braun of Gotha. This is followed by a paper by E. Turner in which is given an analysis of the braunite of Elgersburg in Germany?. Turner neglects a residue of silica, which he characterizes as a trace and determines the manganese protoxide by difference. In this way Turner arrives at the conclusion that braunite is a sesquioxide of manganese oi the formula MngQ0xg, or, as he puts it, ‘an anhydrous deutoxide of manganese ’. Since then only two other analyses have been published that show braunite to correspond to this formula. These are of specimens from Arkansas by R. N. Brackett and W. A. Noyes 3, and Elba by C. Bechi 4, the percentages of silica being 0°18 and 0:75, respectively. As the braunite of Elgersburg was later analysed by Rammelsberg 5 and found to contain 8°63 per cent. SiQ9, it seems as if the only analyses of braunite, corresponding to the formula MngO3, on which it does not seem possible to cast reasonable doubt are those of the Arkansas and Elba specimens. But it is to be noticed that another analysis of Arkansas braunite shows 9°97 per cent. of SiOg, the analysis being by W. Elderhorst 6. Nevertheless, it seems necessary to recognize the possible existence in Nature of a mineral with a composition correspond- ing to the formula Mn,O3; it must be extremely rare. All other observers have obtained a residue of gelatinous silica on dissolving the mineral in hydrochloric acid. From its gelatinous condition it seems as if this silica must have been present not as an impurity, but as a constituent part of the mineral. The subject is well summarized in the already-cited paper of Rammelsberg and in Penrose’s book on manganese, pages 151 to 153. Hermann? , writing before the essential presence of silica in braunite had been recognized, supposed, in order to account for the fact that braunite is not isomorphous with hematite, Fe203, that the composition of the non-siliceous braunites is more truly represented by the formula MnO.MnOg, than by MngQO3 : this was on the analogy of the view previ- ously advanced by Berthier8 that the composition of the proto- 2 Op. cit., p. 167. 3 Penrose, Ann. Rep. Geol. Surv. Arkansas for 1890, Part I, p. 149. 4 Am. J. Scr., 2nd Ser., XIV, p. 62, (1852). 5 Pogg Ann,, CXXIV, p. 517, (1865). 6 First Report of a Geological Reconnaissance of the Northern Counties of Arkansas, by D. D. Owen, pp. 164, 165, and 169, (1868) (Penrose). 7 Jour. f. pr. Chem., XLIII, p. 50, (1848), (Rose). 8 Annales de Chimie et de Physique, XX, p. 186, (1823), (Rose). Cuap. III. ] . (i. BRAUNITE. ) 65 G. Rose ! took up this idea, and in view of the known presence of silica in most specimens of braunite, attempted to show that SiOg and MnO, isomorphously replace one another in this mineral. He gives the fol- lowing as the most general formula of the mineral, allowing in it for the presence of small quantities of various protoxide constituents replacing the manganese protoxide, MnO :— MnO ) MnO FeO, FeO SiO. z' MnO, CaO | CaO MeO J MeO J He then considers as derivatives of this formula the braunite of Elgersburg, which had not then been shown to contain silica, and the variety of this mineral from St. Marcel in Piedmont, called mareceline by Beudant? in 1832, and analysed by Damour 3, These two varieties would then have the formule :— : MnO ? Braunite Mn0O2 BaO ) Mn0Oz2. Marceline MnO i SiO2 Rammelsberg 4 then analysed the braunite of Elgersburg and found that it contained 8°63 per cent. of Si09g. He considers that the mineral is an isomorphous mixture of manganic oxide, Mn Os, and manganous metasilicate, MnSiOs, the various protoxides that often enter into the composition of the braunite replacing portions of the MnO of the MnSi03. He gives as the formula :— 3 Mn 3 Mn203 + MnSiO3 = ae } 09, 5 Except for the fact that Rammelsberg regards the oxide portion of the formula to be manganic oxide, MngQg3, this is essentially the formula put forward by Rose, who, however, regards the oxide por- tion as composed of MnO.MnOy. Rammelsberg draws attention to the analogy between the formula of braunite as he has expressed it and that of ilmenite, which may be written as — m¥e,0,+ (Fe, Mg)0.TiO, = (Fe, Ti,Mg),0,. 1 Pogg. Ann., CXXI, pp. 318-325, (1864). 2 ‘Traité élémentaire de Minéralogie’, II, p.188, (Dana). 3 Annales des Mines, 4me. Ser., I, pp. 405, 406, (1842). 4 Loc cit., p. 519. 5 The analysis given by Rammelsberg agrees much better with the formula 7Mn20Q3 + 2MnSiO3, than with the one given, I F 66 MANGANESE DEPOSITS OF INDIA: MINERAL | arg ft: J. D. Dana!, in order to bring out the crystallographic relation of this mineral to rutile, gives the formula as :— 2 (2Mn0.MnOz) + MnQ2.SiOz. Later, however, E. 8. Dana2 adopts Rammelsberg’s formula ; in the meantime Rammelsberg, as the result of the discovery of the different behaviour of the Mn Os in manganite, a mineral which is isomorphous with the corresponding iron mineral gothite, from that of the Mng03 in braunite, when the minerals are subjected to the action of con- centrated nitric acid, changes his views? and admits the probability that the Mn 0x of braunite is really composed of MnO.MnOy,. In this case he says that the formula may be— Mn MnO + Oz Si Bauer 4 supposes braunite to be an isomorphous mixture of MnO. MnO, and MnO. SiOg, in which a portion of the MnO is replaced by BaO. Flink5 in a paper on the Langban braunite gives the formula as RO.ROg, and arranges the analysis he has made of the braunite of this locality as the sum of manganous manganite, MnMnOs, and of metasi- licates of Mn, Fe, Ca, and Mg, of the general formula RSi03.6 From a discussion of the various analyses given below I propose to show that it is probable that Flink’s method is the correct one and that braunite is to be regarded as an isomorphous mixture of manganites of the general formula RMnOs, and of metasilicates of the general formula RSiO3. This can be stated more generally as — mRMnOz + nRSiO3 ; 1 “ System of Mineralogy’, 5th Edit., p. 133, (1868). 2 Op. cit., Gth Edii., p. 233, (1892). 3 Sitzungsberichte der k. wreuss. Akad. Wiss., 1885, 1, pp. 97-100. 4 * Lehrbuch der Mineralogie’, pp. 317, 318, (1886), (Penrose). 5 Ak. H. Stockh. Bihang, XVI, (2), No. 4, p. 9, (1890). r 6 Since this was sent to the press I have been able to obtain copies of M. Al. Gorgeu’s paper ‘ Sur les oxydes de manganese naturels ’, issued in three parts. These three parts deal with the following minerals :— ; Part I. Bull. dela Soc fr. Mineralogique, III, pp. 21-31, (1890). Psilomelanes and wads. Part II. Bull. de la Soc. Chimique de Paris, 1X, pp. 496-502, (1893). Polianites and pyrolusites. ; Part II. Ibid., pp. 650-661. Manganites, hausmannites, and braunites, __ As the result of analyses of, and experiments on, braunites from St. Marcel in Pied- mont, and Schwarzenbourg in Prussia, Gorgeu concludes (noticing also the analyses of Rammelsberg and Damour) that braunite can perhaps be regarded as representing an acid salt with the general formula (Mn, Si)O, RO, in which the acid portion is formed by a combination, in slightly variable proportions, of silicic and manganous acids, and in which the basic portion consists of a number of oxides, amongst which MnO largely predominates, He finds that this combination is only broken up by heat when the temperature exceeds that corresponding to a cherry-red, Cuap. III. ] BRAUNITE. 67 In all the analyses considered the ratio of m: n lies between the limits 3: 1and4:1. As manganese is the predominant basic constituent the formula can be more definitely stated as— m MnMn0O3 + 2 MnSiOs3. On the supposition, which has yet to be proved, that the Si in a metasilicate is isomorphous with the Mn in a manganite, this formula can be further simplified to — Mn(Mn,Si) O3. The most general ratio of m to n is perhaps 3:1; so that the formula of braunite can be conveniently expressed as — 3MnMn0O3 + MnSiO3. In attempting to find out to which of the various formule proposed the Indian braunites correspond I have three analyses to reply upon, These are shown below. The specimen A. 345 was obtained frgm the ore heaps at Garividi station of the ore quarried from Garividi deposit, where, as is noticed on page 1055, all the ore is of detrital character, the ore-body mm situ not having yet been uncovered. This quarry, however, happens to be the locality from which the best specimens of braunite are to be obtained in the Vizagapatam district. The specimen was black and lustrous, showing perfect cleavage and the most brilliant reflections from these cleavage faces. It was a portion of one crystal showing a cleavage face over 3 inches long. The portion of it broken off for analysis weighed 25 grammes, and had a specific gravity of 4°79. This braunite can be taken as typical of that formed chemically in the deposits of the kodurite series. The second specimen, No. 1110, was obtained by carefully breaking up two or three crystals of the braunite occurring in the albite veins at KAcharwdhi in the Nagpur district, and making sure that there was no albite in the specimen taken for analysis. This mineral in outward appearance was identical with the Garividi speci- men, showing the same black lustrous cleavage. The weight taken for analysis was 2°69 grammes, of a specific gravity of 4°79. This braunite can be taken as typical of that which occurs in veins of igneous origin. The third specimen, 16°815, was obtained after a tedious separation, carried out by Mr. T. R. Blyth of the Geological Survey of India, from a rock composed of this mineral, winchite, calcite, and quartz, sent by Mr. H. J. Winch from Kajlidongriin Jhabua State, Central India. The product of the separation consisted of a large number of tiny grains of a lustrous black mineral that under the microscope showed many triangular faces, indicating an octahedral shape for the crystals. From the fact that this mineral was found to be decidedly I F2 68 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: magnetic, and the fact that the amphibole, winchite, with which it was associated contained a considerable proportion of magnesia, it was supposed that analysis would show this mineral to be jacobsite. The amount obtained for analysis was 3°05 grammes; Mr. Blyth found the specific gravity, by Penfield’s method, to be 4°70. Analysis has, however, shown that the mineral contains 10 per cent. of SiO, and that it is allied to braunite, if it cannot be actually relegated to this species. It is to be regretted that no analysis has yet been made of the braunite that occurs in the braunite-psilomelane mixtures of the C. P. The results of these analyses are shown below. The Garividi and Kacharwahi specimens were analysed by Messrs. J. and H. S. Pattinson of Newcastle-on-Tyne, and the Kajlidongri specimen by Mr. Blyth. TABLE 7. Analyses of Indian braunites. Garividi. Kacharw ahi. Kajlidongri. Number of specimen A. 345 1110. 16°815. Manganese peroxide 37°06 40°23 40°93 Manganese protoxide 36°72 41°85 37°98 Ferric oxide . 14°14 5°50 1°45 Alumina 5 . 0°90 0°44. 0714 Baryta 0°56 0°53 0:09 Lime 0°78 ieils3 3°85 Magnesia 0°56 0°38 4°36 Potash . 0:13 0:16 es Soda : 0°21 015 Sie Silica (combined) 8°25 8°60 10°26 Sulphur 0°03 0°04 ae Phosphorie oxide 0°07 0°08 = Arsenic oxide Nil Nil P Cobaltous oxide 0°05 0°20 5 Nickelous oxide Nil Nil : Cupric oxide . 0°03 0°05 ; Lead oxide Nil Nil S Zine oxide Nil Nil ae Titanie oxide i; 0°06 0°03 30 Chlorine and fluorine Nil Nit ae Combined water . 0°25 0°38 Ste Moisture at 100°C. 0°25 0710 1°57 Carbon dioxide Nit Nil . 100°05 99°85 100°63 Manganese 51°88 57°86 55°29 Tron 9°90 3°85 1°01 Specifie gravity 4°79 4°79 4°704 Cuap. III. ] BRAUNITE. > 69 For the purpose of calculating from these figures it is found to be necessary to assume that the ferric oxide replaces an equivalent quan- tity of manganese sesquioxide, Mn,O3, and that the oxides of barium, calcium, and magnesium, replace equivalent amounts of manganese protoxide, MnO. Neglecting, then, all the constituents of the analyses, except the MnOg, MnO, Fe203, BaO, CaO, MgO, and SiOg, and replacing the oxides of iron, barium, calcium, and magnesium, by equivalent amounts of manganese oxides, and splitting up the Mng03 so obtained from the Fe203 into MnO and MnOg, the composition of the three Specimens works out as follows :— Garividi. Kacharwahi. Kajlidongri. MnO 45°22 46°64 51:21 Mn02 44°75 43°22 41°72 SiOz 8°25 8°60 10:26 98-22 98°46 103-19 Manganese 5 : 63°32 63°45 66°05 Available oxygen . ; 8°23 7°95 767 Reduced to 100, these correspond to :— Garividi. Kacharwahi. Kajlidongri. MnO 46°04 47°37 49°64 Mn0O2 45°56 43°90 40°42 Sid2 8°40 8°73 9°94 100°00 10000 100°00 Manganese . . . 64°47 64°43 64°00 Available oxygen . - 8°38 8°07 7°43 The formula for braunite usually given in text-books of mineralogy is that of Rose and Rammelsberg (see page 65); Lut this corres- ponds to 9°98 per cent. of silica. Although some of the published analyses show this amount, many of them show a considerably smaller quantity of Si0y. This probably means that the relation of Mng0x to MnSiO3 is not always 3: 1, but is sometimes greater than this value. 70 MANGANESE DEPOSITS CF INDIA: MINERALOGY. [ Part I: Consequently I have given below the composition of braunites corres- ponding to ratios of 3:1,7:2 and 4:1, sespectively :-— Formula. 3Mn2O3. Nnsi0s, 7Mn203. 2MnSiO3. | 4Mn203. MnSiOs } MnO . fs : : 46°91 46°69 46°51 MnOz . : : ; 43°11 44°49 45°58 Si0g . é 5 : 9°98 8°82 791 100-00 100-00 100°00 Manganese. . : 63°59 64°29 64°85 Available oxgyen . : 7°93 8:18 8°38 Or, if the manganese and oxygen be stated in terms of MnO and MngQz3, the figures are as follows :— MnO. ° g : 11°73 | 10°38 9°30 78 29 On comparing with these figures the analyses of Indian braunites given above it appears that the Garividi specimen corresponds almost exactly toa formula lying half-way bet..een the formule corresponding to the second and third columns. This formula is 15Mn903.4MnSiOg, the ratio between Mn,0g and MnSiOz being 33: 1 instead of either 34: 1 or 4: 1. The Kacharwahi specimen, on the other hand, corresponds very closely to the formula 7Mn,03.2MnSiOs, the chief points to notice, in comparing the figures given on page 69 with those for the formule given above, being the amounts of manganese, silica, and available oxygen, the amounts of the oxides of manganese being of less value in making this comparison because a small error in the determination of the available oxygen produces a considerable change in the ratios of the peroxide to protoxide of manganese. The figures, as given on page 69, deduced from the Kajlidongri analysis, correspond most closely with the formula in the first column ahove, namely to 3Mn 03.MnSi03. The most noticeable deviation from the theoretical formula is in the ratio of the oxides to one another. This, however, corresponds to a relatively small error in the determina- tion of the available oxygen. From the consideration of the foregoing three analyses it appears Cuap. III. ] BRAUNITE. a that the three different examples of braunite correspond to the three following formule :— Garividi 15Mn203.4MnSi0g = 19Mn0.15Mn02.48i0» = = 19[MnO + (Mn,Si)02] Kacharwahi 7Mn203.2MnSi03 = 9MnO.7MnO02.2Si02 = 9[ MnO +(Mn,Si)02] Kajlidongri 3Mn203.MnSi0g = 4Mn0.3MnO2.Si0g = 4{MnO +(Mn,Si)O2] It will be seen from the above that although the formule of these three specimens of braunite show three different ratios of MngO03 to MnSiOs, yet the number of molecules of the manganese protoxide is equal in each case to the sum of the number of molecules of the dioxides MnO, and SiOz, so that the three formule can be re-arranged as 19, 9, and 4 times the formula MnO + (Mn,Si)Oz ; the difference between the three braunites lies in the ratio of Mn to Si in the (Mn, Si) group, being 15: 4, 7: 2, and 3:1, that is 32:1, 34:1 and3: 1 in the three cases. The formula MnO + (Mn,Si)O. may thus be taken as the general formula of braunites free from appreciable quantities of replacing constituents. It must be remembered, however, that in making the above calculations, portions of the manganese were put in the place of the oxides of iron, barium, calcium, and magnesium, returned in the original analysis. At first sight it might seem a difficulty that the iron was returned in the original analysis as Fe,0s3, and that there is no sesquioxide group in the above formula for braunite that the iron could replace. It must be remembered, however, that there is no means of telling in what condition the iron really was in the original mineral. To fit in with this formula it must have been in the ferrous condition with a corresponding proportion of the manganese originally returned as protoxide in the peroxide form. On this view the general formula that takes in all the above varieties is— (Mn,Fe,Mg,Ca,Ba)O + (Mn,Si)Oz. In most cases the amounts of baryta, lime, and magnesia are smali, so that, although it is necessary to take them into account in the cal- culations, they can be omitted from the formula. The most usual formula for braunite will then be— (Mn,Fe)O + (Mn,Si)Os. In the case of braunites containing only an insignificant amount of iron the formula can be further simplified into— MnO + (Mn,Si)Oz. Since the ratio between the Mn and Si in the (Mn, Si) group is a variable one it is evident that there are two further possible simplifications 72 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: of the above formula. One of these is when the ratio of Mn to Si is infinity. Then the formula becomes— MnO + MnO2 = Mn203, thus taking in the doubtful cases of minerals having the simple formula Mn203. The other alternative is when the ratio of Si to Mn is infinity. The formula then becomes— MnO + SiOz = MnSi03, which is the formula of rhodonite. In pursuing this variation of the formula to its logical conclusion I am not suggesting that there is necessarily any direct connection between braunite and rhodonite, especially as one is tetragonal and the other triclinic in crystallization. To establish this connection it would probably be necessary to prove the existence of a series of compounds of gradually increasing ratio of Si to Mn, corresponding, of course, to an increase in the ratio of MnSiOg to MngO3 in the other method of expressing the formula of braunite. I have considered this general formula for braunite to show the connection between the different varieties of this mineral, as other- wise it might be considered necessary to propose different names for minerals of different formule. I do not, however, suppose that it is a true formula as regards structure. It is more probable that a change in the ratioof Si to Mn indicates a change in the number of molecules of MnO+Si0g relative to molecules of MnO + MnOg, and nota change within the molecule itself. The formule of the above specimens of braunite, making due allowance for the more important of the replacing constituents, work out as follows according to the mR O03 + nMnSi03 method :— Garividi : > . 15(Mn,Fe)203.4MnSi Os. Kacharwahi . - . 7(Mn,Fe)203.2MnSiO3. Kajlidongri . : : 3Mn203. (Mg,Ca) SiOs. In the first two cases the alkaline earths are not present in sufficient quantity to be entered up in the formula. In the third analysis the iron is sufficiently insignificant in amount to be omitted from the formula ; but it so happens that the MgO and CaO are just a little more than suffi- cient to replace all the R in the RSiO3 group. Hence it seems that this is to be regarded as a rather unusual variety of braunite, exhibiting, more- over, a lower specific gravity than usual, namely 4°70, this being, of course, due to the replacement of manganese by magnesium and calcium. To see how the braunites of other countries fit in with the formule given above I have reduced some of the published analyses of foreign braunites into terms of oxides of manganese and silica, by replacing lime, Cuap. III. } BRAUNITE. 73 magnesia, baryta, and oxide of iron, with equivalent amounts of man- ganese oxides, and then reducing the whole to 100 in exactly the same way as was done above in the case of the Indian braunites. Of the five examples given below, all except that by Igelstrém are in papers already quoted. | | | Elgersburg. St. Marce’. Jakobsberg., Langban. | Arkansas. | ! ! Analyst. | Rammelsberg. Damour. Igelstrém.1 Flink. |Elderhorst. ——— >Mu=0. O so that it is a manganous manganite analogous in composition to manganous metasilicate— » ia >si=0. 0 This supposition is also supported by G. Bertrand! in order to allow of the replacement of Mn by Ba in the basic portion of the mineral, and of Mn by Siin the acid portion of the mineral. This is of course practically equivalent to a return to the idea of Rose that the SiO, can isomorph- ously replace MnO g. It seems indeed as if the structure of braunite can be very conveniently explained in this way, according to which it would be an isomorphous mixture of molecules of MnMnOs, CaMnQOs, BaMnOs, FeMnO3, MnSi03, FeSiOs, etc., in varying proportions, the limits to the replacement of molecules of the form RMnOg by molecules of the form RSiOs3 being that prescribed by the ratios 3: 1 and4:1. Itis probable, in view of the fact that the varieties of braunite yet analysed do not show any very large amount of replacement of MnMnOs3 by FeMnOs or other similar molecules, that there is also a limit to this replacement consistent with the mineral still possessing the form of braunite. The extent to which this replacement of one molecule by another can take place so that the mineral still exhibits the characteristics of braunite is a point that will need a large amount of investigation and one that can pro- bably be solved only by an attempt to make the different varieties artificially. If, however, the views expressed above be correct one would expect the replacement of molecules of the form RMnOx by ones of the form RSiOg to take place gradually between the limits3:1 and4:1. The 1 Revue générale de Chime, VIII, p. 208, (1995). j Cuap. III. | BRAUNITE. 75 figures that are the most explicit in this respect are those for the Si09. If the replacement be gradual, the amounts of silica found in a suffi- ciently large series of analyses of braunite should be distributed evenly over the whole of the range between the percentages corresponding to the two limiting forms of braunite, namely between the values 7°91 and 9°98. The eight values of the silica given above can be arranged in the following order— 7°68 near 7°91 for 4Mn203.MnSiO3. a65. 8°72, 8°73, near 8°82 for 7Mn203.2MnSi0O3. 9°80, 9°94, 10°02, near 9°98 for 3Mn203.MnSiO3.- It will be seen that all except one of these group themselves close to the values for one of the fixed ratios 3: 1, 7:2, and 4:1. Hence it would seem that braunites of these definite ratios, only, exist, and that the mixture is not truly isomorphous, owing perhaps to a definite combination taking place betweem the MnMnO3 and the MnSiOg when the composition corre- sponds to these definite ratios. This is of course a question that can only be settled when a much larger number of analyses have been made. Iam inclined to think that the grouping shown by these analyses may be accidental and that the admixture of MnMnOg and MnSiO3 may take place in any proportions between the limits 3: 1 and 4: 1. In dealing with the analyses of composite specimens of ore scattered through the descriptive portion of this Memoir, I have assumed for the braunite the most generally accepted formula, namely 3Mng03.MnSiOs3, containing a percentage of 9°98, or practically 10, of silica. The advantage of this formula is that if the combined silica in the analysis be taken and multiplied by 10 the product gives very closely the percentage of braunite in the ore. And in the Central Provinces, where the ores are mixtures of braunite and psilomelane, it is found that by taking this formula the ore works out almost exactly in most cases to a mixture of braunite and psilomelane in a proportion that agrees with the appearance of the speci- men. Consequently if the complete analysis of a piece of Central Prov- inces ore be taken and the combined silica multiplied by 10, this will give the percentage of braunite ; and the remainder, after taking out the P.O; as apatite and any free silica as quartz, will be psilomelane ; or as the amounts of apatite and quartz are usually insignificant, the remainder after subtract- ing the braunite can be reckoned to be psilomelane. This method can even be applied to the calculation of the approximate composition of a sample of which only a partial analysis is available. Thus, the partial analysis (No. 3) of Ramdongri ore given on page 858 shows 5°19 % of combined silica. This corresponds to 51°9 per cent. or roughly 52 per cent. of braunite, 76 MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ Parr [: \ leaving a remainder of 48 per cent., which, as the amounts of free silica, phosphoric oxide and moisture are not large, can be taken as roughly corresponding to the percentage of psilomelane in the ore. That is the composition of the sample can be taken as roughly 52 per cent. of braunite, and 48 per cent. of psilomelane. The method of calculating out a complete analysis into terms of its mineral composition is explained on page 108; many examples of such re-arranged analyses will be found scattered through the pages given up to the description of the deposits of the Nagpur district. Occasionally the percentage of braunite calculated in this way seems to be considerably less than the aspect of the specimen would lead one to expect. An example is the analysis of a specimen of coarsely crystallized ore from Lohdongri given on page 917. This ore would seem to contain at least 80 per cent. of braunite. Calculation in the ordinary way only shows a percentage of 68°5 per cent. of braunite. This probably means that the braunitein this ore has one of the other formule, probably 7Mn 03.2MnSi03 containing only 8°8 per cent. of silica, instead of 10 per cent. as in the braunites of the formula 3Mng903.MnSiO3. This would give a percentage of 77:4 of braunite; whilst the formula 4Mn20s3. MnSi03, corresponding to 7:9 per cent. of silica, would give 86°3 per cent. braunite in the ore, and one of these two latter figures would seem to correspond more exactly with the aspect of the ore than the first. Appendix.—Since the foregoing was sent to the press, Mr. Blyth has a Nae siee a been able to analyse the braunite of Sitapdr in the ae Sitapat Chhindwara district, Central Provinces. The mineral taken for analysis was obtained from the complex ores of this locality, consisting of sitaparite, hollandite, braunite, pyrolusite, and an arsenate. The braunite occurs in small black lustrous grains. The amount obtained fit for analysis was 1-14 grammes. The specific gravity was found to be 4°798. The result of the analysis ig shown below :— Specimen No. 843 C4. Manganese peroxide : ; : . 37°10 Manganese protoxide . : a - : : : 5 » a0 Ferric oxide . 2 * : : 2 - - . : - «92 Alumina ~ 3 - : ; : : : | : =“ 8092 Baryta = - - - 5 - : : - : : . trace Lime . é - : . : : : : : - : - 2228 Magnesia . - 5 : : - . - ° - 5 J sOn08 Silica . : A 4 Z 4 3 4 4 : * - 8°62 Moisture at 100°C. - - : : - - 5 é : 31) Oslo) 100 °88 Manganese . . . . . F : . : . ° . 55°28 Iron . - - 7 - A C “ 2 ‘ - : . 6264 Cnap. III. ] POLIANITE. Tl By converting the lime and magnesia into equivalent amounts of manganese protoxide, and the ferric oxide into its equivalent of Mn203, the figures given in column No. 1 below are obtained. In column No. 2 these figures are given reduced to 100. No. 1. No. 2. MnO F ‘ 3 , : 3 - s 51°69 50°87 Mn0Og F ‘s ; ‘ : - : 3 41°41 40°75 SiO ea pr ete” TE Ca eee 8-52 8-38 101 -62 100 -00 Manganese ; 3 5 . , F fi 66°20 65°16 Available oxygen : - : : 7-62 7-50 On comparing the figures given in column 2 with those for the three varieties of braunite given on page 70, it will be seen that as regards the silica percentage, 8°38, the Sitap4r,braunite lies about half-way between the formule in which the ratios of Mn,O, to MnSi0, are 7: 2 and 4: 1, respectively, the actual ratio corresponding to this silica _per- centage being 15: 4, as in the Garividi specimen. The amounts of MnO, MnO3;, and available oxygen are, however, considerably different from what they should be if the braunite has this formula. This difference can be easily explained on the supposition either that there isanerror of 0°78 percent. in the oxygen determination, or that all the protoxides do not form a portion of the braunite, and so should not all have been converted into manganese protoxide in the foregoing calculations. The formula of this braunite on the supposition of an error in the oxygen determination would be 15Mn,0,.4MnSi0, ; whilst on the supposition that a portion of the pretoxides of lime and magnesia does not form a portion of the braunite, the formula would be 4Mn,0O.. MnSi0,. a Polianite. Polianite is a mineral crystallizing in the tetragonal system in forms isomorphous with tin-stone. It has a composition represented by the formula MnOg, is too hard to be scratched by a penknife (H.—=6-6'5) and has a specific gravity of 4°83-5°03. Its colour is light steel-grey to iron-grey, with a black streak. This is one of the rarest of the oxide minerals of manganese and is found at Platten in Bohemia. ane It has not yet been for certain identified amongst the Indian ores. Some specimens of manganese-ores were recently sent to the Geological Survey Office from the Bikonhalli deposit (known as Norton’s Block), Shimoga district, Mysore, by Mr. Claude Fawcitt, chemist to the New Mysore Manganese Company. Amongst them is one, the characters of which suggested polianite. In general colour 78 MANGANESE DEPOSITS OF INDIA : MINERALOGY. [PartlI: it is light steel-grey, with a dead-black streak. It is slightly mag- netic, has a hardness of 65 and specific gravity of 4°80, determined on & piece weighing 54 grammes. This piece was powdered and the analysis kindly undertaken by Mr. Fawcitt. The result was as follows :— Mn0Ozg = aa ac 92°55 MnO 5. sl ae 2°69 Fe203 ate ae oe 1°60 Al203 <= = Se 0°70 CaO a a <5 061 ; MgO oot a 0°25 r P205 te -- a5 0°07 r CO2 St ae Be trace SiOz — 0°80 Combined water (by difference) 0°73 100700 The unusually large amount of manganese peroxide shows that the mineral is different from the other manganese-ores found in India ; of these the only mineral that contains such a high pezcentage of MnOg is pyro- lusite, which is much too soft for the present mineral. Considering this fact there seems no alternative to regarding the mineral as polianite rendered impure by the presence of some 7} per cent. of foreign material, present either as another mineral mechanically mixed with the polianite, or as impurities mechanically included init. If the former be the case then it is probable that the other mineral is braunite, in which the silica would be contained. [A careful examination of the specimen with a lens seems to show that it is made up of two constituents of which one might be braunite and the other hollandite, the latter being present in by faz the larger amount. But the analysis renders it improbable that this is the composition of the ore and consequently it is necessary to suppose that the mineral that suggests hollandite is really polianite. I shall not, however, be satisfied with this determination until I have obtained some definitely crystallized specimens of the mineral showing the crystalline form of polianite. | Pyrolusite. Pyrolusite is the peroxide of manganese, MnO», containing, when theoretically pure, 63°22 per cent. of manganese. It crystallizes in the orthorhombic system in forms that are supposed to be the result of the formation of this mineral from manganite by dehydration; the manganite (Mn903.H20) giving up its water, with the production of pyrolusite (MnO») often containing a certain proportion of residual water. At the same time the manganite Characters. Cuap. III. | PYROLUSITE. 79 loses its hardness (4) and the resultant pyrolusite is probably only an agetegate possessing the outward shape of the manganite, but having the hardness characteristic of pyrolusite, namely 2 to 2°5, this mineral being very soft and soiling the fingers. Its specific gravity is given as 4°73-4°86. In colour the mineral varies from black to steel-grey and bluish-grey with a black streak. The lustre of the mineral is metallic. In India this mineral is found at a large number of localities, at some of them in considerable quantities. In Mallet’s Mineralogy of India, pages 57 to 59, an account is given of the various occurrences of this mineral discovered up to the time that work was written, (1887). I do not propose to notice in this place all’ the occurrences of this mineral in India ; for it would be very tedious and take up a large amount of space; the more important of them must suffice. References to this mineral will also be found throughout the descriptive part of this Memoir, and a reference to them can be obtained from the index. Tt i is a pretty common mineral in the manganese-ore deposits of the Vizayapatam district, that is in those derived from the rocks of the kodurite series. Here it occurs more or less massive as a bluish-black ore of fine grain. This ore often exhibits little cavities lined with silvery black mammillations of the same mineral. An analysis of a picked specimen of this ore is given in the table on page 82. Sometimes the oreis found in sufficient quantities to be stacked separately from the other ores of the mine. This I saw being done at Kodur. In the mines of this area the pyrolusite seems to be most commonly formed by the replacement of the quartz- felspar-recks accompanying the manganese-silicate-rocks, from which the replacing manganese is derived. A figure illustrating this method of formation is given on page 1085, Occurrence. In the manganese-ore deposits of the gondite series, that is those occurring in the Central Provinces and Jhabua, this mineral is the least common of the three common minerals of manganese, braunite, psilome- lane, and pyrolusite. In fact at a large proportion of the deposits it is not found at all, except perhaps as traces ; and of all the deposits of this type the only one at which it occurs in any quantity is Kurmura or Ponwardongri in the Bhandara district, where there was a huge upstanding mass of ore composed of this mineral and psilomelane. The pyrolusite is fine-grained soft and blackish (see page 752). At Pali, in the Nagpur district, there is an occurrence of very fine and pure pyrolusite in cavities in crystalline limestone, in which it has been 80 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [Part [: deposited after the formation of the limestones, which contain piedmon- tite,* either so as to fill in cavities dissolved out by percolating waters, or by the metasomatic replacement of the limestone under the influence of percolating manganiferous solutions. This deposit has been to a certain extent quarried with the extraction of a considerable quantity of very pure mineral. An analysis of asample of the mineral is given on page 957, and an analysis of a picked piece of the ore in the table on page 82. The latter analysis shows the ore to be very pure pyrolusite, the most noticeable feature being the extremely small quantity of iron, namely 0:04 per cent. Such an ore is admirably suited for glass manu- facture, for which it would probably fetch a high price. The ore itself is found as beautiful concentric mammillary specimens reflecting a silky black lustre from the rounded surfaces of the mammillations, which are often of considerable size, namely one inch or more across. Plate 3 shows a piece of this ore. Amongst the ores formed by replacement at the outcrops of rocks of the Dharwar series, pyrolusite is very commonly found, as for example, at Tawargatti and Chik-Vadvati in the Dharwar district (pages 642, 645) ; in the manganiferous area south of Chaibdsa in the Singhbhum district (page 619) ; at numerous localities in the Jabalpur district, especially in the rocks known as the Gosalpur quartzites (pages 811—814); and in most of the deposits of Mysore and some of those of Sandur. Pyrolusite, for analyses of which see pages 657, 659, is also found at Sivardjpur in the Panch Mahils district, Bombay. These ores seem to have been formed by the replacement at the surface of the quartzites of the Chémpaner series, the equivalent of the Dharwars of other parts of India. In the ores of lateritic origin pyrolusite is also one of the commonest minerals and is to be found at all the localities where ores of this origin are found. For a list of these areas see page 385. There is nothing of especial interest to notice about these ores except that they frequently show open spaces or cavities lined with small stumpy prismatic or flattened crystals which sometimes seem to be proper pyrolusite and at others seem to be intermediate between manganite and pyrolusite. From their crystalline shape they may once have been manganite. [A good example of pyrolusite formed by the alteration of manganite is figured on Plate 22, Vol. XXXIII, Records of Geological Survey of India, the specimen figured coming from Ramandrug in the Sandur Hills; bu this is not from true laterite]. Of the lateritic pyrolusites perhaps the ‘AZIS TWHOLWN f ‘dO ‘LOINLSIG UNdOWN ‘M¥d WOUS !3LISNIOYAd "0D agdpozoyyZ VPNIPVI “You “A “qd “A Aq *o1oud ‘€ ‘Id ‘IIAXXX ‘IOA ‘SHOWA VIGCNI JO ALZAXAS TVITIOTOLI Crap. ITI. | PYROLUSITE. 81 most famous is that of Gosalpur in the Jabalpur district. Central Provin- ces, for analyses of which see page 813. The masses of pyrolusite found at this place are sometimes as much as | to 1} feet in diameter. When broken open they are usually found to be partly cavernous with small crystals of pyrolusite lining the cavities. Of the fine specimens in the Geological Museum, Calcutta, it is not, however, certain which have been derived from the laterite at Gosalpur and which from the nests and pockets of this mineral that occur in the Gosalpur quartzites. Fair quantities of pyrolusite have also been found at Mansakra in the same district. Pyrolusite is also sometimes formed as a recent deposit, for an example of which the occurrence at Pan Kuan in the Dhar Forest may be cited (page 675 and Plate 15). Here the wineral is associated with what is probably tufa. : The black dendritic markings of manganese oxide often found on the bedding and parting planes of rocks are usually referred to pyrolusite ; the best Indian examples are those found on the bedding planes of Vindhyan sandstone; see Plate 4, which is only $ natural size. Dendrites are often found in the Indian manganese mines. In the following table I give some analyses of picked specimens of Indian pyrolusites. The first specimen was sent from Bikonhalli in the Shimoga district, Mysore, by Mr. C. S. Fawcitt. The pyrolusite formed a magnificent black lustrous crust of small crystals resting on cavernous ore composed of limonite, pyrolusite, psilomelane, and manganite (?). Some of these crystals were detached and carefully picked. The analysis was kindly undertaken by Mr. Fawcitt. Thesecond specimen was sent by Mr. H. J. Winch from Ghatia in Banswara State, Rajputana. It showed some rather dull, longish, prismatic crystals of nearly square form implanted on some fine-grained manganese-ore, probably composed of a mixture of braunite and psilomelane. These prisms gave a black streak, were scratched by fluorite, and gave off a little water in a closed tube. The specific gravity of some of these detached prisms was found to be 4°94, a little high for pyrelusite. The analysis of the picked sample was under- taken by Mr. Fawcitt. The third specimen was obtained from a heap of picked ore at Kodur in the Vizagapatam district, Madras. It was a fine-grained crystalline piece of ore with cavernous spaces lined with shining mammillations of pyrolusite. The piece taken for analysis was some two inches in diameter, but its specific gravity was not determined on account of the soft and friable character of the mineral. This I G Analyses. 82 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ PART]: specimen was analysed by Messrs. J. and H. 8. Pattinson of Newcastle- on-Tyne, The fourth specimen was a piece of the radiate-concentric vyrolusite of Pali in the Nagpur district, referred to above. It was analysed at the Imperial Institute, London, where the specific gravity was found to be 4°88, the piece used being of some 2 inches in diameter. The analyses are given below :— TABLE 8, Analyses of Indian spyrolusites. | Bikonhalli, Ghatia, Kodur, Pali, Shimoga. Banswara. |Vizagapatam.| Nagpur. 1707 K. 193. |yo-407 N° *! al t97 932. | | MnO2 96°73 97°04 92°31 | 95°57 MnO 0°57 0°43 1°82" | (OR4E Fe203 0°23 0°03 0°07 0°06 Alg03 0°18 0°17 0°27 0°43 BaO ae Oy | 0°99 1°34 CaO 0°66 OFS 0°31 0°00 MgO 0°76 O:47 } 0°05 0°09 K20 | : nil | 0°31 trace NazO or nil | 0°11 0°13 SiO2 ; 0°42 0°41 0°502 0°332 Sulphur . | Pat 4 0°016 Me P205 a 0 °956 0°01 As205 0°009 | 0°012 CoO?) Ie ne Eee 34 | 7 | 0-10 | 00163 NiO ; : ‘ ; : 5: | ae nil 45 CuO ‘ ; 5 5 oa} “iva is 0°005 | bO : : 2 ; 5 || ar eS nil | ZnO ‘ E 2 Fi c 3.0 aC 0°10 dicd Combined water F P can 0-451 0°35 2°00 1°46 Moisture at 100°C... A | Pa a 0°25 0:12 Carbon dioxide : : site| = | be nil 0:09 100-00 99-87 | 100°176 100-068 Manganese : . al 61°57 61°68 59°78 60-79 Tron 6 5 ‘ : «| 0°16 0:02 0°05 0:04 Pho ‘phorus | | 0°42 0:004 pa ee ee Se ee Specific gravity . 5 4 | | 4°94 | | 4°88 a em a ee a I Sa SR RL RR RE ES 1 Bo difference. 2 All combined silica. 3 Mainiy cobalt oxide, c ‘AZIS TWUYUNLVN « ‘YNNWd ‘ANOLSGNVS NVAHGNIA YaddN NO 30IXO S3SANVONVW 3O SSLINGNAG ‘VIGNI IWYLNAO *youey “A “Ad *H Aq ‘oV0Nd "02 aghzojoygq vj{nIVD v ‘Id ‘TIAXXX ‘[OA\‘satoway ‘VIGNI JO AXAYAS TKIIDOTODD ” 5 : : ' CHap. IIT. MANGANITr: 8&3 Manganite. Manganite is a hydrated oxide of manganese having the formula Mn203.H20. It crystallizes in the orthorhombic system in prismatic crystals usually exhibiting several different prism faces ; the termina- tion is usually a basal plane, although this is some- times absent, pyramid and dome faces being develop- ed instead. The crystals are often many times longer than broad, then assuming a needle-like aspect. The colour is stated to be steel-grey to iron-black and the lustre sub-metallic, with the streak reddish brown to nearly black. Hardaess =4. Specific gravity = 42-44. When pure the mineral contains 62°50 per cent. of manganese and 10°23 per cent, water. Characters. According to Mallet a specimen of this mineral has been obtained from the Political Agent at Gwalior, and hence pre- sumably from that neighbourhood.! I have shown elsewhere that this specimen? is probably only pyrolusite, although the crystals may be pseudomozphous after manganite. Occurrence. In a paper in the Records of the Geological Survey of India, Vol. XXXITI, pages 229-232, I have described and figured an example, there supposed to be manganite, occurring as a lining to a geode found on the outcrop at Ramandrug in the Sandur Hills. At the time this paper was written this was the only known specimen of this character, Since then, however, Mr. Aubert, who obtained that specimen, has pre- sented to the Geological Survey several more similar specimens from the same locality. The specimen described in the paper exhibits well the long needle-like habit, showing usually the faces of a prism, sometimes accom- panied by other bevelling prisms, with for termination either the basal plane or, more rarely, a couple of minute faces that suggest the macro- dome. The mineral differs from typical manganite in that it doeg not seem to give off, when heated in a closed tube, a large enough quantity of water, probably owing to incipient change to pyrolusite. It is noticed that the perfect cleavage of manganite parallel to the brachypinaccid b (010) causes it to decrepitate violently when heated in a closed tube, the mineral splitting along this direction.. The lustre, moreover, is not sub-metallic as stated by Dana, but brilliantly metallic, the colour being, moreover, bronze, due perhaps to a superficial tarnish. 1 Mineralogy of India, p. 59, (1887). 2 Rec. Geol. Sur. Ind., XXXIII, p. 232, (1906). 84 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ ParTI: Since the foregoing paragraph was written I have been able to visit the manganese-ore deposits at Ramandrug and Kamataru in the Sandur Hills, and find this supposed manganite myself. It occurs in drusy cavities in the ore-bodies, and may occur in either wad or psilomelane. Specimens can be found showing every gradation between the hard bronzy-lustred mineral mentioned above, and a shining black mineral of exactly the same radiate character, but as soft as pyrolusite, which it then undoubtedly is. Of the specimens sent by Mr. Aubert some of the harder bronzy-lustred mineral was separated from the associated ores and the specific gravity of a piece weighing 2°19 grammes found to be Chemical compo- 4°470. This being only slightly higher than the Biuont value of this constant for the unaltered manganite, which is 42-44, it was thought that analysis would show this piece to be nearly fresh manganite. The analysis was undertaken by Mr. C, Fawcitt of Shimoga with the following result :- Mn0O2 c ; é 0 c - > - 92°90 MnO c c : : : : . ' : - Lay Fe203 and Alg03 (mostly AlgO3). . F c 0 = ess CaO c 4 ~ . 2 - . . . a) 30286 MgO - : ‘ : 2 a c , C 3 en Oka2 SiOg F fs 5 : - : c 5 - 0°47 Combined water . A . . . . A : 1°94 100-04 From this analysis it will be seen that — in spite of the fact that in physical characters the mineral presents considerable differences from pyrolusite, and considerable resemblances to manganite — chemically the mineral is not far removed from pyrolusite. It is true that it still retains nearly 2 per cent. out of the original 10 per cent. of combined water it must have once contained, whilst there is still a small quantity of man- ganese protoxide remaining. Hence we arrive at the dilemma that this mineral, which was once almost certainly manganite, retains to a consi- derable extent the physical characters of manganite, but has been almost completely converted into pyrolusite, as far as chemical composition goes. As it would be most inconvenient to call this mineral pyrolusite, owing to its different physical appearance,-and inaccurate to call it man- ganite, I propose to refer to itas pseudo-manganite. It must be remembered that the above analysis represents only one piece of the mineral. It is possible that if several Pseudc-manganite. Cuap. III. ] MANGANITE, 85 analyses were made of different pieces some of them would be found to approach much closer to manganite in composition. Since describing the first of the Sandur specimens referred to above I have been able to examine a considerable number of specimens of man- ganese-ores obtained from Shimoga and Goa. These ores usually consist of psilomelane or pyrolusite, either separate or associated with one another, and are often cavernous. Sometimes the cavities are lined with mammillations of psilomelane ; sometimes with crystalline growths of Specimens from pyrolusite that may have once been manganite ; and Mysore and Goa. more rarely with needle-like aggregates, of superior hardness to pyrolusite possessing a steel-grey metallic lustre, that are probably to be regarded as either manganite or pseudo-manganite. Judging from specimens sent by Mr. C. Fawcitt from the Shimoga district, pseudo-manganite is probably present in the ores of both Kumsi and Bikonhalli. One of the specimens from Bikonhalli consists of limonite with the cavities lined with psilomelane ; this is frequently coated with a growth of stumpy crystals, probably of manganite or pseudo-manganite, on which the chief form visible is a prism, probably (110); the prisms have a tendency to be united to one another so as to form stellate groups. Specimens collected by Mr. H. D. Coggan in South Goa frequently show nests of what is in all probability manganite (or pseudo-manganite). The localities from which specimens containing this manganite have been obtained are Villian, Kajri Dongar, and Kumari, about 16 miles south of Sanvordem railway station. Specimens of manganese-ores from Puseli in the North Kanara district also often show this supposed manganite. It is not known whether these North Kanara ores are in true laterite or whether they have been formed by the replacement of the outcrops of Dharwar rock (lateritoid). On account of the ease with which manganite suffers alteration with the production of pyrolusite, and the fact that in the course of this alter- ation the manganite often acquires a black streak and looses a large portion of its water long before it has completely passed into pyrolusite, itis often a matter of extreme difficulty to decide whether to call a particular specimen manganite or pyrolusite, and itis to meet this difficulty that I have proposed the name pseudo-manganite for the ex: amples occupying, both chemically and physically, the interval between manganite and pyrolusite. In the following table [ give the characters 86 MANGANESE PEPOSITS OF INDIA: MINERALOGY. [Parr I: that may be made use of in referring a specimen of one of these n:inerals to its proper position, in the absence of a quantitative analysis :-— TABLE 9. Comparison of properties of manganite, ps2udo-manganile, and pyrolusite, | Manganite. | Pseudo-manganite. Pyrolusite, — — - -—— _ — — — —_ —. | —— —- — —_— ——_ — Vormula : 3 : -| Mn,03.H,0. aMnO0.+yMMnO,g + MnOg. zH,9 2) ae = z es | a ees = Hardness : : : : 4 2°5—4 2—2°5 | | | | | ———— Specific gravity . . . 42-44 | 444-7 47419 | Streak . : : : . | Reddish brown) Black. Black. to nearly black.| | | Heated in a closed tube . . | Gives off water! Gives offa liule |Often gives off a water. little water. CHAPTER IV. MINERALOGY—continued. Manganates and Carbonates. Hollandite—Psilomelane—Beldongrite—Wad—Ankerite—Rhodochrosite. Hollandite. This mineral was first brought to my notice by Mr. H. J. Winch at the time of my visit to the Kajlidongri deposit. On examination, I fuuno that the mineral was probably a new one very similar to one I had found at Sitapér in the Chhindwara district. Mr. Winch kindly made a quantitative analysis of it showing that it was a manganate of barium, manganese, and iron.! Having decided that it was a new mineral 1 ‘called it hollandite after Dr. T. H. Holland, Director of the Geological Survey of India, and published a preliminary description of it in the Transactions of the Mining and Geological Institute of India, Vol. 1, page 76, (1906). Since then I have not been able to do any further work on the mineral and thus settle various points that need clearing up, such as its crystallographic system. At Kajlidongri the mineral occurs in the crystatline form in quartz veins traversing the manganese-ore deposit. It aiso sometimes passes into the manganese-ore of the ore-body, which is mainly psilomelane in the parts of the deposit where the hollandite occurs. What is in all probability a variety of the same mineral is found at Sitapar in the Chhindwara district, where it occurs as a constituent of the ores, being associated with sitaparite, braunite, pyrolusite, manganchlorite?, and an arsenate ; Sitapdr is the only locality at which I have found arsenates be- sides Kajlidongri. At the latter place the arsenates are not directly associated with the hollandite, so that this occurence of arsenates and manganates at each of these places may be a purely fortuitous one. Crystalline manganates occur at a few other localities also, associat- ed with the manganese-ores. They have not been definitely isolated and analysed, so that it is not certain how closely mney EEN Occurrence. 1. H. Holland, Ree. Geol. Sue. Ind., XXXII, page 98, (1906). 88 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Parr I: to the composition of the typical hollandite of Kajlidongri. Until more work has been done on these minerals I propose to use the name hollandite to include all the Indian crystalline manganates, though later on it may be found convenient to use the term in a more restricted sense. The other localities at which crystalline manganates occur are Gowari Warhona in the Chhindwara district ; Mandvi Bir, Juna- wani, and Junapani, in the Nagpur district ; and the Balaghat deposit in the district of that name : it is probable that crystalline mangan- ates will be found to be of much more common occurrence than would be suspected from the fact that up till now they have never been recorded as occurring in the natural condition. Wherever a specimen shows psilomelane passing into a crystalline mineral—such as is com- monly seen in the Sandur Hills and Mysore—one must be prepared for the possibility that the crystalline mineral may be hollandite, although as a rule it will probably be found to be pyrolusite or manganite. With the latter mineral in particular it is very liable to be confounded, especially when the manganite occurs in stumpy crystals. But, as will be seen from the account of the properties of hollandite given below, it is easy to distinguish the two minerals if pieces of any size can be obtained. The chief points of difference are the higher specific gravity and, when crystal faces can be used for the test, the superior hardness of the hollandite. A chemical test would also show that the mineral was hollandite if a strong reaction for barium were obtained; but with regard to this latter test it must be noticed that although all the crystalline manganates hitherto found contain a con- siderable proportion of baryta, yet it does not follow that a crystalline manganate will not be found practically free from this constituent.! It might aiso be thought that the presence of water of crystallization in manganite might be used as a criterion in distinguishing these two minerals. It must be remembered, however, that the Indian manganites are almost always in a state of partial dehydration owing to an incipient conversion into pyrolusite, with the result that they often give only a weak reaction for water when heated in a closed tube ; whilst the crystalline manganates, like the amorphous ones grouped under the term psilomelane, may contain water in the form of hydrogen in the base portion of the mineral. Asan example of the confusion that may arise between these two minerals, I may mention that many of the Shimoga manganese-ores contain pseudo- manganite as a lining 1 Such as a crys stalling fom of the America an Hbrous lex ‘a -manganese manganate eoronadite (see page 96). Cuar. IV. | HOLLANDITE 89 to cavities. In most cases the difficulty is only one of determining whether the mineral is to be called manganite or pyrolusite ; but in a few cases, when the crystals are small, or when they pass into more or less massive crystalline material too hard for manganite, it 1s necessary to recognise the possibility that hollandite may be present ; this point can only be definitely settled by isolating some of the mineral and taking its specific gravity, and then, if this be not sufficient, making a chemical analysis of it. *° In colour hollandite varies from a light almost silvery grey through greyish-black to quite black. On both crystal faces and fracture surfaces it has a shining metallic lustre. In the Kajlidongri specimens, the only ones that exhibit definite crystal faces, the hardness is found to be 6 on the crystal faces and only 4 on the fracture surfaces. Owing to the infrequency of crystal faces the hardness test must as a rule be made on fracture surfaces, and therefore the latter figure may be taken as the more general value for the hardness of the mineral. This difference of hardness on the crystal and fracture surfaces is probably due to the fact that whilst the crystal faces are often smooth the fracture surfaces are almost invariably very much striated, so that testing the hardness on a fracture surface consists not in testing the real hardness of the mineral, but in tearing away the fibres of the mineral one from another ; consequently the hardness found by testing the crystal faces must be taken as the true one. As this value is 6, it will be seen that this brings the mineral into line, as far as this property goes, with the hard varieties of the amorphous manganates grouped as psilomelane. The way in which hollandite splits into prismatic chips very much striated on every fracture in a direction parallel to the ver- tical crystallographic axis of the mineral is one cf its most charac- teristic properties, although, of course, when the mineral does not occur in definite crystals it is not evident that the direction of splitting is this axis. The streak of the mineral is black. Physical characters. The crystals that occur in the quartz-veins at Kajlidongri are some- yee times of large size. ; Since my visit Mr. Winch has Meer B kindly collected considerable quantities of this mine- ral as it became exposed in the course of quarrying the ore. Acommon size for the crystals is a diameter of } to dinch, but some of the specimens obtained by Mr. Winch are as large as 1 inch across. In their simplest form the crystals show what looks like a tetragonal prism surmounted by a flat tetragonal 90 MANGANESE DEPOSITS OF INDIA : MINFRALOGY. [ Parr I: pyramid; but the few angular measurements I have yet been able to make indicate that the mineral is either orthorhombic or tricli- nic, more probably the latter, and in either case very closely approach- ing the tetragonal form. The striations on the prism faces and the dullness of the pyramid faces have up to the present prevented this question being settled. There occurs at Kajlidongri a fibrous mineral that shows a beautiful silky lustre. Chemical work on this mineral indi- cates that it is fibrous variety of hollandite; it is probable that the fibres are parallel to the vertical axis of the mineral, this being the direction of the fibrous striation seen on the fracture surfaces of crystals of hollandite. The manganate found at a OR Sitapar occurs in prismatic individuals mixed with Hollandite in the ; : ; Chhindwara district. | Various other minerals, which prevent the mangan- ate from developing true crystal faces. But it shows a prismatic development, the rough prisms being sometimes as long as one inch. At Gowdri Warhona, the mineral is found in certain © Jayers in the manganese-ore in the form of brilliant crystalline interlocking aggregates, the prisms being usually about 1. to } inch in length. This mineral must also be present in the ores of Mandvi AY Bir, Junawani, and Junapani. For the complete Hollandite in the a Av jc as) yoann ores found in the analysis of a piece from Junawani indicates that crystalline limestones, the ore is a mixture of braunite and a manganate, Nie the latter being present in this particular speci- men in the proportion of 66 per cent. The manganate must be either crystalline or non-crystalline. In the latter ‘case the mineral would be psilomelane, which would be easily visible as a dull matrix cement- ing the granules of braunite. But, since the whole piece of ore is cryst- alline, the manganate must be in the crystalline form; thatis it must be hollandite. Inthe same way the physical aspect of the ores of Mo- hugdon, Pali, and Ghogara, in the Nagpur district, taken in conjunc- tion with such partial chemical analyses of them as have been made, shows that they also contain, in all probability, a crystalline manga- nate. At all the localities for this mineral in the Nagpur district the ores are in crystalline limestones. At Balaghdt I collected one speci- men of manganese-ore showing a veinlet about } inch thick of a fibrous silky-looking mineral that at once suggested hollandite. That this is hollandite I have little doubt; for the analysis (No. 1146, page Massive hollandite, 93) that has been made of a picked specimen of Balaghat district. a very common type of crystalline ore in this Fibrous hollandite. Cuap. IV. ] HOLLANDITE. 91 deposit has shown it to be a manganate, which must b~ classed under hollandite. This type of ore is very fine-grained and seems to be crystalline throughout. It cai be scratched with moderat2 ease with a knife and has a brilliant light-erey metallic appearance, so that in the sun it glistens almost like burnished silver, although the colour is some- what darker than that of this metal. By comparison it was found that the near-st approach to its colour could be obtained by looking at a piece of aluminium in ordinary diffused light. This colour corresponds very closely to that of the ore as seen in the sun, although as seen in the shade alongside the aluminium the manganese-ore appears considerably darker. ‘This ore occurs in very large quantities in this deposit, so that many thousand of tons of it must have been exported, hence, even from the commercial point of view, hollandite is, im India at least, an important mineral. This massive fine-grained variety of crystalline manganate occurs in beds of considerable thick- ness and extent, and one may often see, exposed in the quarry, a surface of this ore, many square feet in area, the whole of which exhibits the brilliant appearance noticed above. There is also in this deposit a large quantity of the uncrystallized manganate, psilomelane ; in fact more of it thaa of the crystalline manganate. The first analysis of hollandite was made by Mr. H. J. Winch on a Chemical composi. Specimen having a specific gravity of 4°95, and is tion. shown below :— Manganese peroxide (MnQ,) . . 65°63 Manganese protoxide (MnO) . . 5°12 Ferric oxide (Fe, Og) . . 10°56 Alumina (Al,03) . 5 . : 0:94 Baryta (BaO) : : q 2 17°59 Silica (SiQ,) . : : . . traces 99°84. This analysis corresponds to the following formula :— m({ Ba,Mn),MnOs + (Fe, Al)4(MrOs5)s3. or m(Ba,Mn),MnOs5 + 2(Fea(Mn0Os)s, according as the alumina be considered an essential constituent or not.! iMr. T. R. Blyth, Assistant Curator, Geological Survey of India, has examined this mineral more carefully than was possible to Mr. Winch in his rough jungle laboratory and finds that it contains, in addition to the constituents found by Mr. Winch, small amounts of lime and magnesia and of one of the rarer elements, which has not been yet identified. The precipitate obtained in Group II on passing HS has been examined spectro- scopically by Prof. Noel Hartley and found to consist chiefly—in addition to sulphur —of barium sulphate and titania. Subsequently Dr. Morris Travers examined some of the original mineral and found that the HS precipitate contains traces of second- group elements to the extent of one part in 7,000. A careful analysis of the mixed sul- phides showed them to consist principally of antimony with traces of arsenic, bismuth, and copper, the last two in exceedingly minute quantities, 92 MANGANESE DEPOSITS OF {NDIA : MINERALOGY. [ PaRTlI: Of the hollandite of other localities the only one of which an analy- sis is available is the massive variety of the Balaghaét mine. On pages 797 and 971, however, analyses are given of picked pieces of ore consisting in the main of mixtures of braunite and a crystalline manganate. These analyses are recalculated into terms of their mineral composition, showing the manganates as composed of a series of man- ganates of the various base radicles of the mineral. The figures for the composition of the manganate as given on those pages I have con- verted to a total of 100, so that from these analyses of composite speci- mens it has been found possible to extract analyses of the crystalline manganate or hollandite. Cuap. IV. ] HOLLANDITE. 93 These analyses, together with the analysis of the massive hollandita from Balaghat, are given below :— TABLE 10, Analyses of hollandite. 5 Gowari Balaghat Warhona Number of Specimen 1146 7521 Manganese peroxide {MnOg2) 75:05 | 71:25 Manganese protoxide (MnO) 9°02 14:20 Ferric oxide (Fe2Q03). 4°43 5°73 Alumina (Al203) . 1:04 0:42 Baryta (BaQ). 2°96 722 Lime (CaO) 031 0°38 Magnesia (MgO) 0°36 0°35 Potash (K20). 3°31 i Soda (Na2O) . 0°57 Combined silica (SiOz) 1°30 Free silica (SiOg) 0°10 Sulphur : ; 0021 Phosphoric oxide (P205) ; 0046 Arsenic oxide (As205) A a é nil Cobaltous oxide (CoO) . : : . 0°05 Nickelous oxide (NiO) . : ° : nil Cupric oxide (CuO) . trace | Lead oxide (PbO) nil Zine oxide (ZnO) trace Titanic oxide (TiQ2) 0:03 Chlorine and fluorine nil a Combined water (H20) 1:10 0°45 Moisture at 100°C. O15 oe Carbonic oxide (CO2) nil Manganese Tron Siliea (total) Phosphorus 54-42 | 5604 3-10 | 401 1:40 _ 0-02 | § Junawani. a 1 Since these calculations were made the following additional constituents have been determined at the Imperial Institute :— | NiO, Cog04, CuO | KeO Na20O | 0-011" | O08 022 | 0°33 0°23 | 0°32 | | * Chiefly cobalt. + Chiefly nickel. Thsee would of course correspond to small quantities of manganates, 94 MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ PartI: In terms of the different manganates these analyses can be re-stated as follows :— TABLE 11. Analyses of hollandite in terms of mang sn+tes. Semen el \ | Gowazi Balachat. Junawani. Ss a Warhona. 1146 752 | 1062 | en A es Pee Fe4(MnOs5)3 8°71 | 11°26 18°20 Ala(Mn0Os5 jg 2°61 1-12, 2°74 BagMn0O5 3°95 9°63 741 CagMnQs5 0°59 | 0°74 480 MgeMnOs5 0°82 | o-7s KaMn0O5 512 ars Na4MnO5 ; i g Fi ; F 104 or Co2MnO5 : : . : , 0-08 ae cits HaMn05 : 2 . 3 5 3 : 3°96 17 0°23 MneMnOs : 5 “ : : : : 70°71 74°72 66°62 97°59 160°00 100°00 Surplus oxygen : ; : : : : 0°61 SiQe2 5 : é : 5 : : s 1°40 S y . E 3 A = : - 0021 PoG5 Cr : : : : : : - 0°046 TiOs 7 < : s 5 ‘ : 0°03 Moisture at 100°C. . 1 : - ‘ ; O15 99°847 For compzrison I have re-stated the analysis (given on page 91) of the typical hollandite in terms of its constituent manganates :— Fe4(Mn0O5)3 20°76 Al4(MnO5)3 2°36 BaoMnOs5 23°50 MnoMnOs 53°59 100°21] Oxygen assumed 0°37 99°84 Cuap. IV. | HOLLANDITE. 95 It should be noticed that in calculating the mineral composition of composite specimens of ore from their analysis, a difference is usually found between the amount of oxygen determined and that required for the manganates left over after the braunite has been extracted from the analysis. This difference is, however, never sufficient to point to the presence of some other compound rather than manganates corre- sponding to the theoretical acid H,Mn0O; ; in fact the errors are always sufficiently small to be attributable to experimental errors in their determination. The differences between the amounts of oxygen required for the manganates in the above analyses and the amounts actually found are as follows :— per cent. Kajlidongri —0°37 Balaghat +0°61 Gowari Warhona +0°85 Junawani —0°52 These differences may, as already stated, be due to experimental errors in the determination of the oxygen, but the discrepancies can be explained in another way. In the cases where there is a surplus of oxygen it may be that a portion of the manganese forming the basic radicle of the mangan- ates is not in the protoxide form corresponding to the formula MngMn0O;, but is in the sesquioxide form corresponding with the formula Mn,4(MnO;)3. The conversion of the requisite amount of MngMnO; into Mn,4(MnO5)3 would account for this surplus oxygen. In the same way when there is a deficit in the amount of oxygen according to the above way of representing the mineralogical composition of the ores, this deficit can be accounted for by the conversion of an equivalent amount of ferric manganate, Fe,(MnO;)s, into the ferrous manganate, Fe :MnO;. This point must for the present remain open to doubt; but it is to be noticed that in the case of some of the analyses of psilomelane the discrepancy is perhaps too great to be attributable to experimental errors. From the foregoing paragraphs it follows that the composition of these crystalline manganates can be represented by the general formule given below, in which the constituents are placed in order of import- ance in their respective brackets :— m (Mn,Ba,Ke, H2,Ca,Mg,Fe,Co)2Mn0O5 + n(Fe,Al,Mn)4(MnO5)s. This is, of course, the most general formula, but it can be simplified, by omitting the least important constituents, as follows :— m (Mn.Ba,K2,H2),MnO5 + (Fe,Al)4(MnOs)s. 96 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: In any particular case a more definite formula can, of course, be given. Thus the three analyses given above correspond roughly to the following formula :— Balaghat m(Mn, Ba, K2,H2)2MnO5 + n(Fe, Al)4(MnO5)3. Gowari Warhona m(Mn-Ba)2MnO5 + nFe4(Mn0O5)3. Junawani m(Mn,Ba,Ca)2 MnO5 + n(Fe,Al)4(Mn0O5)s. As will be seen from these formule these manganates correspond to the hypothetical acid H,MnOs;, and it seems as if there is a whole series of compounds derived from this acid by isomorphous replacement. Laspeyres | has already suggested that psilomelane may conform to this formula, and we see that the existence of compounds corresponding to this formula is put beyond doubt by the discovery of the definitely crystallized minerals here described. As will be shown under the heading of psilomelane this latter mineral also conforms to the formula suggested by Laspeyres, at least as far as can be judged from a large number of analyses of Indian psilomelanes. Hence it seems probable that hollan- dite is to be regarded as the crystalline form of psilomelane, there being no essential difference in chemical composition between the two minerals, An interesting problem for future solution is to find out what deter- mines whether the mineral takes the crystalline or amorphous form, and why it is that crystalline manganates, which are by no means un- common in India, are not found wherever psilomelane occurs in all parts of the world.2 It is interesting to note that W. Lindgren and W. F. Hillebrand [ Amer. Jour. Sci., XVIII, pp. 448-460, (1904) ] describe a ay ote Tet new mineral from Arizona under the name of corona- dite. They regard their analysis as indicating the mineral to be a salt of a derivative of ortho-manganous acid, H,Mn,0,. I find, however, that their analysis corresponds very closely with R, MnO,, where R—=Mn and Pb chiefly. The mineral is fibrous, and 1 Jour. fir prak. Chemie, XIII, p. 215, (1876) [Dana]. 2 It isinteresting to note that M. Al. Gorgeu in a paper called ‘Sur les oxydes de manganése naturels’, Bull. dela Soc. fr. de Mineralogique, III, (1890), says, on page 22, that the interior of a specimen of psilomelane from Romanéche, in Sadne et Loire, France, was crystalline. He gives analyses of both the exterior non-crystalline portion, and interior crystalline portion. He calculates out formule for these specimens, and also for specimens of psilomelane froni Thuringia in Germany, and Lorsa in Spain, according to which psilomelanes ave hydrated manganites with ‘ bases multiples et variées’, I find, however, that both the Romanéche analyses can be converted into a series of ruanganates of the form ReMnO5, the oxygen errors, however, being rather large, namely deficits of 1-44 and 1:00; but these would have been less had I taken account of the arsenic oxide of which amounts of 1°50 and 0:70 % are shown in the two analyses, and converted it into arsenates, I think it is probable that this crystalline psilomelane is identical with hollandite. The non-crystalline and crystalline portions contain 16°20 and 14°45 per cent. of BaO, respectively. Cuap IV. | : PSILOMELANE. eRe Ne if hence corresponds to the fibrous variety of hollandite. At present I see nothing that certainly shows the reason of the formation of crystalline manganates at one time and non-crystalline ones at others. An examina- tion of the analyses of hollandite shows, however, that the crystalline manganates always contain a fair quantity of barium and iron; this may indicate that the manganates can only assume the crystalline form in the presence of fair quantities of these two elements, although the number of analyses available is not really sufficient to base such a general statement upon. Such a hypothesis would explain why ores low in these constituents were found as psilomelane and not as hollandite, but it would not explain the case of varieties of psilomelane containing as large quantities of iron and barium as hollandite. Hence it seems more probable that the reason for the formation of crystalline manganates at one time and non-crystalline ones at others is to be looked for in the conditions of formation rather than in the chemical composition of the mangapates. As might be expected, the great variability in the composition of the manganates from different localities is accompanied by a corresponding variability in the specific gravity of these minerals. Thus a picked specimen of this mineral from Sitapar in the Chhindwara district was found to have a specific gravity of only 4°70, whilst the specimen analysed by Mr. Winch from Kajlidongri had a value of 4:95 for this constant. Determinations of the specific gravity of several other picked specimens from this locality have given values ranging from 4°93 to 4:99. The massive specimen of hollandite of which the analysis is given on page 93, had a specific gravity of only 4:59, this low value being in all probability due to the fact that the specimen was an aggregate and not a piece of a separate crystal. It should be noticed, however, that these values for the specific gravity correspond roughly with the differences in the amounts of baryta present in each specimen, the values of this constituent in the Kajlidongri, Sitapdr and Balaghdt specimens being 17°59, 6-20. and 2-96, respectively. Specific gravity. Psilomelane. Of all the manganese-ores found in India, this is the mast abun- dant; with braunite it makes up by far the larger proportion, probably at least 90 per cent., of the manganese-ores exported from India. Its existence in India was apparently first recognized by A. J. Scott in association with I H Occurrence. 98 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [Part 1: the braunite of the Vizagapatam district!. As this mineral occurs at almost every locality where manganese-ores are found in India there is no point in enumerating all the different occurrences of it. An account of all those recognized up to 1887 will be found in Mallet’s Mineralogy, page 61. In addition to the localities mentioned by Mallet many others have, of course, since been recognized and a reference to these can be obtained from the index to this Memoir. In the Nagpur- Balaghat area of the Central Provinces, in Jhdbua, Narukot, and the Panch Mahals, the psilomelane often forms an intimate mixture with braunite, which occurs scattered throughout in small granules to which the psilomelane acts as a cement. (See Plate 1.) With increasing quantities of braunite, or of psilomelane, there is a gradual passage into ore which is practically all braunite on the one hand and all psilomelane on the other. In the Vizagapatam district, also, the ores often consist of psilomelane containing scattered braunite; but in this case the braunite patches are often larger than is customary in the Central Provinces, whilst they are less abundant. In fact ore consisting of psilomelane free from braunite is very common in this district, whilst in the Naégpur-Balaghat area of the Central Provinces it is compara- tively rare, Guguldoho, Balaghat, and Ukua, being the only notable localities. In the other areas where this mineral is found in quantity it is not associated with braunite, except perhaps occasionally in minute quantities, but occurs either alone or in association with pyrolusite. The more important of such areas are the following ;—Belgaum, Goa, Jabalpur, Mysore, Sandur Hills, Satara, and Singhbhum. According to Dana’s System of Mineralogy, page 257, 6th Edition, psilomelane exhibits the following characters :— It occurs either massive, or in botryoidal, reni- form, or stalactitic shapes. G = 3:°7—4:7; Hardness = 5—6, z., it can sometimes be scratched by a knife and at other times cannot. Lustre submetallic, dull. Streak brownish black, shining. Colour, iron- black, passing into dark steel-grey. Opaque. Physica! characters. The Indian psilomelanes agree fairly well with the above diagnosis. The best example of massive psilomelane is probably that of the Balaghat deposit in the Central Pro- vinces, where this mineral forms massive beds alternating with layers of quartzite and of massive hollandite. Botryoidal shapes, that is, those stimulating more or jess closely a bw ch of grapes in shape, are perhaps best exemplified in some of the ores found in the Satara district, Form. 1 Ridin, New Phil. Jour., LIU, p. 278, (1852). GEOLOGICAL SURVEY OF INDIA. Memoirs, Vol. XXXVII, Pl. 5. Photo. by H. B, W. Garrick. Fig. 1.—STALACTITIC PSILOMELANE FROM GARBHAM, VIZAGAPATAM DISTRICT, MADRAS. 3} NATURAL SIZE. s From a Sepia Sketch, Calcutta Phototype Co, Fig. 2,—RENIFORM PSILOMELANE FROM GARBHAM, VIZAGAPATAM DISTRICT, MADRAS. 4 NATURAL SIZE. ‘AZIS TVYUNLVN ¢ ‘'d ‘O ‘LOINLSIG YNdOVN ‘OHOGTNONS WOUYS ANVIAWONSd GALVITIWWYA—'S “814 "0D agdjozoyg vpnyvz "3ZIS 17n4 (L16 ‘¢t) IVONZ LOINLSIG WAHSHONIS ‘IvSvYNaL ‘SUNLOVYS AIVGIOHONOOD DSNIMOHS ANVISAWNOTISd—'T “814 ‘ ‘soy "MW “A ‘H Aq ‘o1oyg ‘9 ‘Id ‘IIAXXX ‘0A ‘Stowayy ‘PICNI AO ALAYAS TVITIDOTODLI e y 7 a2 : a A Crap. IV. J} PSILOMELANE. 99 especially at Yeruli. The best example of this mineral I have seen showing a reniform shape is a specimen found loose at Garbham in the Vizagapatam district (see fig. 2, Plate 5). At Guguldoho I found a very fine specimen of psilomelane with a form that can be best described as liver-shaped or hepatiform. The specimen as first found was some 10 inches across and resembled nothing so much in shape as the liver of one of the large carnivora, such asa panther. It was made up of concentric layers and is the specimen No. 1157 of which an analysis is given on page 100. At this locality is to be found almost every variety of -concretionary structure exhibited by psilomelane, there being many fine examples of mammillary forms. Fig. 2, Plate 6, shows one of these. The best example of stalactitic psilomelane I have seen from India was found by Mr. Geeson at Garbham in the Vizagapatam district (see fig. 1, Plate 5). According to Dana the lustre varies from sub- metallic to dull. This applies to most of the Indian psilomelanes, but there is one variety, found at Garbham and Avagudem in the Vizaga- patam district, and at Kumsi and other deposits in Mysore, that on fresh fracture resembles very closely in colour and lustre a piece of metallic - lead, so that its lustre can be described as metallic. This is the variety of which an analysis is given on page 100 (No. A. 372). The streak of this mineral is said by Dana to be brownish-black in colour. Although this undoubtedly holds for some examples, yet the Indian psilomelanes have, as often as not, a black streak. In colour the Indian specimens vary from iron-black through dark steel-grey to an almost bluish-grey, this bluish tint being especially noticeable when one is collecting specimens in the blazing sunlight of an Indian dry-weather day. It will be noticed that the specific gravity of the specimens of which re analyses are given on page 100 all lie between the Seno limits given by Dana. They tend, however, to be almost invariably over 4 in value, the only exception being the lead- like variety. I have already mentioned in discussing the composition of hollandite, which is to be regarded as the crystalline form of this mineral, that analyses of both minerals con- form very closely to the formula first suggested by Laspeyres, so that both psilomelane and hollandite can be regarded as derived from a hypothetical acid of the composition H,MnO;. Below i give a series of five analyses carried out by Messrs. J. and H. S. Pattinson of New- castle-on-Tyne on specimens collected by myself. For the purposes of analysis I picked out pieces that were as homogeneous as could be Composition. I H2 100 MANGANESE DEPOSITS OF INDIA : MINERALOGY. [Pant 4: found, carefully took their specific gravities, and sent to the analysts the whole of the specimen in the powdered condition. Central Provinces; Avagudem in the Vizagapatam Nagpur district, Guguldoho is in the district, Madras ; and Tekrasai in the Singhbhum district, Bengal. TABLE 12. Analyses of Indian psilomelanes. Manganese peroxide (MnOg) Manganese protoxide (MnO) Ferric oxide (Fe2Og) . Alumina (AlgO3) Baryta(BaO) . Lime (CaO) . Magnesia (MgO) Potash (K20) . Soda (NagO) . Combined Silica (SiOz) Free Silica (SiO2) Sulphur . Phosphoric oxide (P20s) Arsenic oxide (As205) Cobaltous oxide (CoO) Nickelous oxide (NiO) Cupric oxide (CuO) Lead oxide (PbO) Zine oxide (ZnO) Titanie oxide (TiOg). Chlorine . - Fluorine . Combined water (H20) Moisture at 100°C. Carbon dioxide (CO2) Manganese Tron ; Silica (total) Phosphorus Specific gravity Guguldoho. 99°994 57°78 1:05 0°25 0°366 Avagudem. nil 100°175 | 49°18 4°00 0°45 0°346 Tekrasai. | ‘ | Tekrasai, trace nil 3°30 0°45 nib 100°086 50°66 O15 0°05 0°322 100°083 55°61 0°05 0°05 0°295 Tekrasai. 100°151 Se ee ee | 57:14 0°35 0-10 0304 4°26 3°86 4°54 44] 4°38 Cuap. IV. | PSILOMELANE. 101 It is noticeable what a large percentage of P20; is present in all these specimens of psilomelane. The quantity is in fact so large that the amount of CaO present is not nearly sufficient for the phosphoric oxide to be present as apatite. It is not known therefore in what form the P,0; is present is the mineral. I can only suggest that it forms a phosphate with some other base than the lime, possibly a manganese phosphate. In the absence of any knowledge on this point I have been compelled to disregard this constituent in considering these analyses. In the same way the small amounts of sulphur, possibly present as barytes, and the minute quantities of TiO, and of As,O;, have been neglected ; whilst, in view of the small amount returned (0:05 to 0°45 per cent.),I have not made any allowance for the combined silica ; that is, I have not used it to form a corresponding amount of braunite, especially as no such second mineral is evident in the speci- mens. Leaving these constituents out of consideration, therefore, the foregoing analyses can be arranged in terms of manganates as follows :— TABLE 13. Analyses of Indian psilomelanes in terms of mangunates. Guguldoho.'Avagudem. Tekrasai. Tekrasai. | Tekrasai | 1157 A. 372 A. 380 A. 381 J. 917 | Fes(Mn05}3 . wt 2°95 11-22 0-41 0-14 0-98 Al4(MnOs5)3 : - 038 | 892 0°75 1°88 113 BazgMnOs5 : - - 0°04 3°25 20°14 6°89 2°76 CagMnOs5 - - - 0°40 1-04 O15 0°56 0°90 Mg.Mn0Os5 0-41 0°57 0°57 0°50 0°36 K4Mn0O5 4:79 3°02 | 0°31 3°60 4:07 Na4MnO5 0°82 COL. O27 0°33 0°33 Co2Mn0O5 017 0725 =| 0°42 0°34 0°59 NizMnO5 5¢ 0°34 0°25 9:08 Cu2Mn0O5 0°07 0°13 0°07 0°02 Zn2MnOs | 0°24 0°49 0°65 0°S0 H4Mn0Os5 - : < 137125) |) 1266) = 12:78 10°03 10°22 MngMnO5 : : - 74°74 52°90 6228 72°39 75°12 97°82 — | 9818 9899 | 9768 | 97-46 102 MANGANESE DEPOSITS OF INDIA : MINERALOGY. | [ Part I: TaBLE 13—(contd.). Analyses of Indian psilomelanes in terms of manganates. | | Guguldoho.|Avagudem. Tekrasai. | Tekrasai. Tekrasai. 1157 | A372 | A380 | A 381 | J. 917 Carried forward j : 97°82 98:18 98-99 | 97°63 97:46 SiOz é : : ; 0°25 0°45 0:05 0°05 0°10 Sulphur . : z 5 0:021 0:034 0°039 0°037 0:025 P205 ; : : : 0°838 0°791 0°737 0°676 0696 AseO5 ; : , 0003 ar a CuO : ; ‘ : 0:002 | ne a ae ae TiOg ; : : : 0-01 te a Ba oe Moisture at 100°C. _ 025 | 2°05 045 | 0°45 0°35 99°194 101°505 100°265 | 98°843 98°631 Surplus oxygen : : 0°80 ae Bi | 1°24 1°52 Oxygen assumed a¢ ; A 99°994 100°175 100°086 | 100°083 100°151 It will be seen that on the assumption that these specimens have the respective compositions given above there is a considerable error in the oxygen determination. But, as in the analyses of hollandite, these diff- erences can be explained on the assumption that in the case of an excess of oxygen a corresponding portion of the manganese is in the form, not of manganous manganate, MngMnO;, as shown above, but of manganic manganate, Mn4(MnOzs)3 ; whilst in the case of a deficit the difference can be explained on the hypothesis that a portion of the iron is in the form of ferrous manganate, Fe,MnOs, instead of ferric manganate, Fe4(MnOs)s, as represented. ‘To show what difference this would make I will take the cases of the analyses in columns 2 and 5, where there is a deficit of 1°33 of oxygen in one case and an excess of 1°52 of oxygen in the other. In the former case the oxygen can be obtained from the ferric manganate in accordance with the following equation :~- 3Fe4(MnO5)3 = 6Feg2MnO; + MneMnOs +10 O; according to this equation the deficit of 133 of oxygen could be obviated by the conversion of 15°69°% Fe4(MnOs)3 into 12°32% FegMnO; + 2°049% MnoMnOs + 1°33 % of oxygen. The only difficulty in the way of accepting this interpretation is the fact that there is Cuap. IV. ] PSILOMELANE, : 103 not so much ferric manganate available to be converted iuto ferrous and manganous manganates and oxygen. Still the difference, namely 4:47 of ferric manganate, only corresponds to an oxygen error of 0°38. In the case of the excess of 1°52 of oxygen, this excess can be used to convert manganous manganate into manganic manganate according to the following equation :— 7Mn2MnO0;5 + 10 O=3Mngq(MnQs)s ; according to this equation 1:52 of oxygen converts 16:29 of MngMnO; into 17°81 of Mny(MnOs)3. In analyses 1157 and A. 381 the surplus oxygen is enough to convert 8°57 and 13°29 of MngMnO; into 9°37 and 14:51 of Mng(MnOs5)s, re- spectively. Making these alterations, the five analyses can be rewritten as follows, leaving the two in which there is an oxygen deficit unaltered and omitting all the constituents that do not come into the manganate molecules :— : iaguldahe Avagudem.| Tekrasai. | Tekrasai. | Tekrasai. : ee oa) <> a | 1157 A. 372 A. 380 A. 381 J. 917 ai pte [i Sar | ER 9 | Fes(MnOs)3_—. P : 2°95 11°22 0-41 0714 0:98 Alg(MnOs)3— : : 038 | 8-92 0°75 1°88 1:13 Mn4(MnOs5)3 9°37 ; ae 14 33 17°81 BagMnOs 0:04 3:25 20°14 6°89 2°76 CagMnO5 | 0°40 1:04 015 6°56 0:90 Mg2MnOs | 0-41 0°57 0°57 0°50 0°36 K4MnOs ; ° iL 479 502 0°31 3°60 4:07 NasMnQs5 ) ) Sri 0;82 0°04 0:27 0°33 0°33 CogMnOs ; : 5 O17 0°25 0°42 0°34 0°59 NigMnOs ; ; i Le a 0°34 0°25 0:08 CugMnOs : ; : i 0:07 013 0:07 } 0:02 ZnoMnOs ; : ; rs 0°24 0°49 0°65 0:90 H4MnOs : 2 : 13°12 14:66 12°73 10:03 10°22 Mn2Mn0Os ; : .| 66:17 | 52°90 62°28 59°10 | 58°85 98°62 98°18 98-99 | 98°87 98°98 If now we want to find out the molecular ratio of manganates of the gene- ral formula R”>MnO; (7.c. all the manganates above, except the ferric, manganic, and aluminic manganates), to the manganates of the general formula R”’ 4(MnOs)s (7.e., the ferric, manganic, and aluminic manganates), then the simplest way is to take the sum of the quantities of the group 104 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: MnOs3 combined with each manganate of the general formula R”>Mn0Os, and divide by 4 of the sum of the quantities combined with the manganates of the general formula R’”4(MnO5)3, nearly all these quantities being ob- tained in the course of calculating the original analysis into terms of man- yanates. These figures work out as follows for each specimen :— | Molecular : : Amounts of | Amounts of | Figures in | aes aii | MnO3 in | MnO3in second be manganates | manganates column BoueO: of the type | of thetype divided by | = » R’gMn05. |R’”4(MnOs)3. to the group | R’”4(MnO5)3. Guguldoho- 1157 . : : 40°10 631 2°10 19°1 Avagudem-A. 372 : . 36°75 10°88 3°63 10°t Tekrasai-A. 380. : : 41°84 0°65 0°22 144°7 Tekrasai-A. 381 . : : 36°49 8°37 2°79 131 Tekrasai-—J. 917 . : : 35°84 9°96 3°32 10°8 Taking the general formula of psilomelane as mR”2Mn0O;+7R’”, (MnO5)3 it is seen that, if m be unity in each case, the value of m in the foregoing examples varies from about 10 to 145, but is usually between 10 and 20. Rammelsberg, in his Handbuch der Mineralchemie, page 182, (1860), regards psilomelane as a combination of potash, baryta, and protoxide of manganese, with peroxide of manganese, corresponding to the formula (Mn,Ba,K»5)O0.(MnOs)9._ In the second edition of his Handbuch der Mineralchemie, pages 189-192, (1875), [Penrose], he divides psilomelanes into two varieties, namely baryta-psilomelane and potash-psilomelane, according to whether the mineral is high in baryta or potash. Dana in his System of Mineralogy, 6th edition, page 257, says that psilomelane is a ‘hydrous manganese manganate in which part of the manganese is often replaced by barium or potassium, perhaps conforming to HyMnO;’, giving Laspeyres! as the authority for this formula, and adding that the material analysed is generally impure, so that the composition is doubtful. The specimens analysed above were apparently pure specimens, so that the results of their analysis can be taken as giving the correct composition. The above calculations show that this mineral does conform to the formula H,MnO;, and that the chief constituents of the basic portion of the mineral, in addition to manganese and hydrogen, are either barium or potassium, although in one case (A. 372) considerable amounts of iron and 1 Jour. fur. prak. Chemie, XIII, p. 215, (1876). Cuap. IV. ] PSILOMELANE. 105 aluminium enter into the composition of the manganate!. It will be noticed, however, that these specimens cannot be conveniently divided into baryta-psilomelanes and potash-psilomelanes. Thus 1157 can be called a potash-psilomelane and A. 380 a baryta-psilomelane, but the other three all contain moderate proportions of both constituents. The general formula mR’’2Mn0O;5 + 2R’’’4(MnOs5)s, to which reference was made above, can be expressed. so as to show the constituents corresponding to R” and R’”’, in the following comprehensive way :— m{(Mn, He, Ba,K2,Ca,Mg,Na2,Zn,Co,Ni,Cu)2Mn05] + n[(Mn,Fe,Al),(Mn0O5)s3]. Omitting the less important constituents in each case, the composition of the five specimens can be stated as follows :— Guguldoho (1157) 19[(Mn,H2,K2)2Mn0Qs5 | Avagudem (A. 372) 10[(Mn.H2,K2,Ba)2Mn05] Tekrasai (A. 380) 145[(Mn,Ba,H2)2Mn05j Tekrasai (A. 381) 13[(Mn.H2, Ba,Ko)2Mn05] Tekrasai (J. 917) 11[(Mn,He2, Ke, Ba)2Mn0O5] (Mn, Fe)4(Mn0O5)s. (Fe, Al)4(MnOs5 )s. (Al, Fe)4(Mn0O5)s. (Mn, Al)4(Mn0O5)s. Mn4(Mn0O5)s3. tte et In these formule I have placed the elements constituting the basic radicles in the order of their importance considered from the point of view of the amount of manganate they form by combination of their oxides with the requisite amounts of MnOs. If R be entirely Mn, then the formula of the mineral becomes Mn2MnO; or Mn305, which would contain 67°359 Mn and 382°65% O. At least two observers have previously suggested the existence of this compound in nature. In one case J. A. Jones? gives an analy- sis of a ‘ cryptocrystalline ’ mineral from Covadanga in Northern Spain, which he thinks corresponds fairly closely to 2MnO2.MnO (=Mn30;). A calculation of his analysis shows, however, an oxygen deficit of 2°81%, if an attempt be made to convert it into 1 I have already noted—footnote on page 96—that M. Gorgeu deduces from his analyses of specimens of psilomelane that psilomelanes are hydrous manganites, but that his analyses of two specimens from Romanéche conform closely to manganates of the general formula R, MnO; He gives the formula corresponding to the Lorca analysis as 6(MnO,) RO..H,O, He regards this, like the other formule given, as a hydrated manganite. The deficiency of the base portion of this formula, as of the others given, is noticeable ; whilst it is interesting to note that the formula given for the Lorca analyses can be re-arranged as follows :— 6(Mn0O,).RO.2H,O = RO.2H,0.3Mn0.3Mn03 =6RO.3Mn03 =3R,Mn03 in which there is no deficit or surplns of either basic or acid radicle, 2 Trans. Inst. Min. Met, III, p. 276, (1894-95). 106 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: manganates. An ore described by E.G. Williams! from Soledad in Panama in Central America, as massive and like psilomelane, was analysed by W. E. Ford in Prof. Penfield’s laboratory. Penfield says the ore agrees well with the composition MnO.2MnOy, or Mn30;, and may be a new mineral species. A conversion of the analysis given into manganates shows that it agrees very well with the formula R’oMnO;, the oxygen error being a deficit of 0°34. I will now give a brief description of the specimens of which the analyses are given on page 98. Each specimen was broken P eevee of into two, one piece used for analysis and the other pecimens. kept for reference. 115 7.—Guguldoho. This piece was a portion of the hepatiform concretion mentioned on page 99. I did not find it im situ, but obtained it from a stack of quar- ried ore. The piece selected for analysis was broken from a concentric shell about ? inch inthickness. It shows a finely concentric structure parallel to the exterior of the shell, the bands being so fine as to impart to the specimen a somewhat satiny lustre. In grain it is extremely fine and in colour a rather light steel-grey, with a bluish tint in the sun. The colour of its streak is brownish black. Its hardness is just over 6, and the specific gravity of the piece analysed 4°26, the closeness of the texture of the specimen being well exemplified by the fact that it did not exhibit any noticeable porosity when left to soak in water. The outer and inner coats of the specimen were covered with a thin brownish skin exhibiting a few minute micaceous scales, but this skin was completely removed before the specific gravity was taken. The fracture is beautifully conchoidal. A. 372—Avagudem., This specimen was selected from the stacks of ore at this mine. This type of ore is rather cavernous and contains both ferruginous patches and soft black patches. After a little trouble, however, some 6 grammes of the mineral free from these blemishes were obtained ready for analysis. This variety has the appearance of slightly tarnished metallic lead, its colour being just a little darker, but its lustre very similar. It appears absolutely homogeneous, and has a brownish black streak, The fracture \ Trans. Amer. Inst. Min, Hn ., XX XIII, pp. 203, 204, (1902). Cuap. IV. ] PSILOMELANE. 107 is beautifully conchoidal. The hardness is 6°5, and the specific gravity, determined on the above 6 grammes, 3°85, the mineral exhibiting no appreciable porosity. A. 380.—Tekrasat. This specimen I extracted from in situ in a pit at Tekrasai in the Singh- bhum district, Bengal, the ore being only about 2 feet below the surface of the ground. In colour it is a dark bluish grey, the lustre being quite dull except for a few scattered specks that suggest the possible existence in the ore of a small quantity of the crystalline manganate, hollandite. In structure the ore is minutely pisolitic, on account of which there are often, between the separate concretions, minute cavities, which sometimes contain a dark brownish black powder, and sometimes are empty. The proportion of material different to the main mass of the ore, which may be described as a dull dark grey variety of psilomelane, is, however, very small and will not have affected the analysis to any large extent. In consequence of this structure, however, the ore is markedly porous, and in taking its specific gravity some day’s soaking were found to be necessary before the weight in water became constant!. The specific gravity was found to be 4°54. The hardness of the specimen is just under 6, and the fracture fairly even, but not conchoidal, the texture not being of the requisite fineness for this. The streak is nearly dead black, there being a slight brown tinge. A. 381,—Tekrasav. This specimen was found 7m situ in the same pit as the preceding one. It is the most fine-grained variety I have yet seen, having more the texture of porcelain than of anything else. It is not, however, hard, but is easily scratched by fluorite and has a hardness of about 3; one of the most interesting features about it is the fact that its fracture surfaces are covered with a sort of black bloom that soils the fingers in the same way as the bloom on a plum does. When this bloom is on, the colour can best be described as a dull iron-black, with perhaps just a tinge of brown. If, however, this bloom be rubbed off with the finger, as it easily can be, the mineral is seen to be a shining iron-black with perhaps a tinge of brown in it. The lustre is perhaps best described as resinous, when the 1 Jn all cases the specimens were afterwards dried by putting them outside on the top of an airbath so as to remove, before powdering for analysis, the water absorbed during the determination of the specific gravity. 108 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: bloom has been removed, being dull before this is done. The streak of this variety is deep brownish black in colour ; its specific gravity is 4°41, the mineral, in spite of its close texture being porous, and thus requiring some 3 days soaking before its weight in water becomes constant. The fracture is beautifully conchoidal. J. 917,—Tekrasai. This specimen was obtained in situ from a different pit to the two preceding. It is also of extremely fine grain, exhibiting beautiful con- choidal structure, the colour being a deep blue-grey, whilst in the sun the fracture surface shows iridescent reflections. The streak is brownish black in colour, the hardness about 5, and the specific gravity 4:38, the specimen being non-porous (see Plate 6, fig. 1). Scattered throughout the descriptive portion of this Memoir will be Galerdatias .¢ found several complete analyses of hand-specimens analyses of braunite- of manganese-ores composed of mixtures of braunite pollomclane orc and psilomelane. It is possible to make use of these analyses for the extraction of further analyses of psilomelane. Before giving a list of such analyses I will give an example of the way in which such an analysis can be re-calculated into terms of its mineral composition. A good example to take will be the analysis given on page 656 of specimen No. A. 607 from Sivarajpur in the Panch Mahals district of the Bombay Presidency. The specific gravity of this specimen is 4°25 and inspection of it indicates that it consists of numerous tiny grains of braunite in a matrix of psilomelane. In calculating the mineral composition the P.O; is first taken out as apatite in the following way, no allowance being made for the requisite chlorine or fluorine (these are stated to be absent ; but the quantity required for the apatite is so small that it would probably be overlooked in the course of analysis) :— 0°366 P205 require 0° 368 x 1°312=0°48 CaO, leaving 1°32 — 0°48—0°84 CaO, and yielding 0° 846 of apatite. The combined silica is next made use of to form brawnite, the formula of this mineral being assumed to be 3Mn903.MnSi0s, since this formula is usualiy found to agree with the analyses very well. For braunite 4°20 SiO, require 78°29 4°20 x ——-+==32°95 Mn203 9°98 11°73 and 4°20 x _—_-=4'94 MnO. 9°98 Cuap. IV. ] PSILOMELANE. 109 It is usually found to be convenient to assume that the Fe.03 present in the ore replaces an equivalent amount of Mn Og in the braunite, although it may also often be regarded as forming ferric manganate, Fe,(MnO;)3, and has been so regarded in some of the analyses scattered through the text. Now 6:00 Fe Ox, is equivalent to 5°92 Mn9Qz, so that for the braunite above only 32°95—5-92 of MngOg is required ; the composition of the braunite is therefore as follows :— Mn203 ; : : . : 27°03 Fe203 5 4 F 5 = (6500 MnO - - 5 A048 Sig ‘ j , : 5 GLY 42°17 Now . . 27°03 Mn203 = 18°82 manganese + 8°21 oxygen. and , soe 42947 MnOne — _ 3582 a + P12 Py totalling . ; : e 3 ve 64 3 + 9°33 Pr Available in analysis = 5 Te) * + 26°03 .*. Temaining for psilomelane . 28°76 PA + 16°70 3 For the formation of psilomelane :— 1°19 Al203 require 1°80 MnOs, giving 2°99 Al4(MnOs)3 0°79 BaO 33 Ou2t 5. » 1°06 BagMnOs 0°84 CaO os Olsiitiemss » 1°61 CagzMnOs5 0 “94 MgO ” 1°20 ” ” 2°14 Mg2Mn05 2°27 K20 ar As, » 3°51 K4aMn0O5 0°23 Nag20- x Omboess » 0°42 NasMnOs oe 0°02 CuO 95 O;OI > » 0°03 Cu2MnOs 0°05 ZnO % OsOdiees » 0°08 ZneMnO05 2 “00 H20 ” 5 al ory ” a call H4Mn05 11°22 MnO3 » 19°55 manganates 11°22 MnO3 E - = 5°99 Mn + 5°23 0 Available .« : . = 28°76 Mn + 16°70 O Left : 4 . = 22°77 Mn + 11°47 O To form MneMnOs, . 22°77 Mn require 11°04 oxygen, yielding . - : - : c 33°81 Mnz MnO5 giving total of psilomelane as . . c : ; 53 36 and leaving a surplus of 0°43 oxygen unused. 110 . MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: This analysis can therefore be rewritten in the following way :— Apatite : : . : : - ; 2 : : . 0°846 Braunite = L x 2 : i z : ‘i . 42°17 Psilomelane Al4(MnO5)3 . 2°99 Baz MnO5 Pel e0G Caz MnO5 «60 Mg2 Mn0O5 . 2°14 K4 Mn0O5 ebSrbl Naa Mn0O5 . 0°42 Cuz Mn05 . 0°03 Zn2 Mn05 . 0°08 H4 Mn05 Bey bef Mng Mn05 33°81 53°36 53 od Quartz (free silica ) : : : 5 * : : ° 1 270 Sulphur : : : “ : - 2 ‘ ~ O;02i TiOg 3 z 5 3 : G E - 0°04 Moisture at 100° C. : 5 = : A " z a « ~ O60 Oxygen unused . 2 : : : : : : : . 0°43 100 "167 Now by taking the above psilomelane and reducing the whole to 100 Calculated analyses We obtain an analysis of this mineral expressed in of pailomelane: terms of manganates; and by a re-grouping of the constituents of the manganates in terms of oxides we obtain an analysis in the usual form. One defect of analyses of psilomelane so extracted from analyses of mixed specimens of ore is that in extract- ing the braunite all the iron oxide is often assumed to replace MngO03 inthe braunite, leaving none for the psilomelane. On examining the analyses of psilomelane given on page 112, it will be seen that, although this mineral often contains but a small quantity of ferric oxide, yet, on the other hand, it sometimes contains a considerable quantity of this constituent. Unfortunately there is often no means of telling in any particular case whether the iron present is in the braunite or in the psilomelane. An other draw-back to this method of extracting analyses of psilomelane is the fact that, as shown under the heading of braunite, the composition of braunite is not a constant one, but usually corres- ponds to one of three formule, namely -— (1) 3Mn203.MnSiOg; (2) 7Mn203.2MnSiOg ; (3) 4Mn203.MnSiOg and there is usually no means of telling which to employ in any partic- ular case. As already mentioned, however, I have assumed the first of these formule in making these calculations ; inthe first place because when I first made them I had not discovered that the formula of braunite does Coar. IV.] . PSILOMELANE. 111 not always conform to the formula given in Dana’s System of Mineralogy, namely 3Mn,03.MnSiO3 ; and in the second place because the difference between the amount of oxygen required with this method of calculation and that actually found is usually not very large. In cases where this error is large, say over 1%, then it might be found that the assumption of one of the other formule for braunite would reduce the difference between the oxygen required and that actually found. But, asin the case of the analyses of specimens of pure psilomelane given on the preceding pages, this difference can be more easily accounted for by assuming a portion of the manganese to be in the form of manganic manganate instead of manganous manganate, in the case of an excess of oxygen ; or by assuming a portion of the iron to be in the form of ferrous manganate instead of ferric manganate, in the case of an oxygen deficit. In the following table are given 12 analyses of psilomelane extracted, in the manner explained above, from the analyses of specimens of manganese- ore scattered through the descriptive portion of this work. In these no attempt has been made to allow for the oxygen difference, but all the iron has been entered up as ferric manganate and all the basic manganese as manganous manganate. [ Parr I: “yyeqoo Aporyy » *A[snolies sesA[vur aaoqe sy} yooye you prnom Aoyy, SIG SeEOMGrON esc a eee =, AON OL <0} SROKOP STO 2 Fa ; O°" *0Z0-0) 080-0} 820-0 OND pur #080) ‘OIN GF-0) LI-0) 83-0 FI-0) FL-0} ZI-0 2 | 680-0) 020-0 LIOT | $66 | MANGANESE DEPOSITS OF INDIA : MINERALOGY. 112 GO-9 G0-9 | 00-001 “EP GGG 8P-0 OCo'V 00-001 0€-99 88-8¢ 96-8 9€-8 F1-0 G€-0 0-0 S1-0 1€-0 L9-0 PL-G LI-T 08-6 €8-P F-S €€-F €Z-F1 69-LI F0-§ $9 A A &} ch | & 5 8 eae coo’ V LOVV g9-S9 L6-OL 6P -Z LO-% ¥6-0 0€-8L FS-6 elie ole ¢) lo | oO sH sH lor bo of 13-3 | 92-0 | 68-1 €L-Z1 as 6-11 = g 2 = = Q Q =] ° ° & & & m a. 4. PW | 680r | FLOT 00-001 | 00-001 Pr-19 | 1F-49 78-61 | 19-48 | 89-0 | GFT c8-£ 60-9 go-F | OG 99-€ | 0-2 ew ee ee lt ate Ree pl aae | - | ze0t | 2101 00-001 | 00-001 0G-18 | Lg-Lg¢ SOuNeuyyE GP-8I | SP-SI | SQuyrH ws OE SQuyysuz Bis Souyyeng SOUNSIN jus-s {) >: sQuyeon ees Hest * SOuyrun | ef . . Sour yy 1:2 Ou soy $8.1 | Soules ae 3s-0 Sounseg be wad “S(SQU)PUE OI-1 Shale * &(SOUIN)FLY res? sr 20) Oe * &(SQUIY) Faq 4 6 B | & La) gg | = = B ‘uornpnojwo fig pauanigo aunjauopsd fo (sajunbunw fo suse, U2) sashpup ‘pl @TaV], Cuap. IV. ] PSILOMELANE. 113 In the second table (No. 15) I give the analyses of the same psilome- lanes arranged in terms of their oxides. On examining these analyses it will be seen that there is occasionally a small surplus of oxygen over that required for the conversion of all the manganese present into peroxide. This, of course, means that in these particular cases the amount of manganese in the form of MnO3 in the manganates is in excess of the amount of manganese in the form of MnO in the base portion of the mole- cule, MngMnO;. I am not aware, however, that such an excess of oxygen over that required to convert all the manganese present in a mineral into peroxide has ever been recorded. Probably it is not to be expected except in the case of a mixture of two minerals, one of which in course of formation probably rejects oxygen from MnOg, taking only the MnO portion, and thus liberates a surplus of oxygen for the remaining mineral, the psilomelane. In this case the braunite perhaps acts in this way. It will be further seen from these analyses that these examples of psilomelane are very variable in composition, apart from the question of whether iron is shown as present or not, this being, as already explained, to a large extent due to whether the iron has been calculated into the braunite or the psilomelane of the original analysis. In several of the analyses the alkalies have not been determined, but cannot be large in amount in these cases, because in the original analyses the totals approxi- mated to 100 without them.! Only one of them shows an important amount of potash. This is the Sivarajpur specimen. The baryta is variable in amount, being in one case nz/ and in two of the Kajlidongri specimens as high as 10°66 and 13:22% respectively. The latter ugure is not surprising in view of the fact that the hollandite of this locality contains 18% of this constituent. In several of the analyses cobalt, nickel, copper, and zinc, have not been looked for.2 But in those in which these constituents were tested for, namely the first and the last five, variable amounts of these constituents were found. Thus in one case, namely M.4 from Sontulai, which might perhaps be better included under the heading of wad than in this place, there is 152% of copper oxide, CuO. The nickel oxide, NiO, is as high as 1-23% in the same -specimen, whilst in one of the Kajlidongri specimens there is 0°90% of cobalt oxide, CoO. 1 These have since been determined ; see footnote to table on page 112. 2 The Co, Ni, and Cu, haye since been determined ; see footnote to table on page 112 { I [ Part I MANGANESE DEPOSITS OF INDIA : MINERALOGY. » {14 | | rset | 86-01 | 9F-8t | het | Le-Ft | LT-FT | GO-FT | L9-9T | 08-9T | SL-91 | 89-FI | 13-91 | ° wedkxo ojqepeay 16-29 | LE-2h | 68-29 | 19-6h | 91-79 | 91-2 | 68-62 | OF-€2 | 93-99 | SI-E2 | 99-19 | 004g | * ° cseuBdaEyy 00-001 | 00-001 | 00-001 | 00-00T | 00-00T | 00-00T | 00-00T | 00-00 | 00-001 00-00 60-00T | 00-00T eL-e | 89-9 | 2-3 | 91-3 |98-% | 99-1 | 2h | 9F-9 | eI-9 | 46-8 | 6F-8 | 6-8 1S .2 Ook 60-0 0€-0 60-0 66-0 ie a ; * @uz 40-0 | &I-0 | 70-0 | 80-0 | 69-1 ; ; oC = * ono oe . +. €3-1} : maa { . 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IV. ] BELDONG RITE. 115 Beldongrite. At Beldongri, on the north side of the pit, there is a variety of mangan- ese-ore, havin a smooth shiny fracture and the colour and lustre of pitch. It is somewhat like the specimen of psilomelane, A. 372, from Avagudem in the Vizagapatam district, of which an analysis is given on page 100; but is more shiny in its lustre, and darker. A piece of this picked for analysis contained a little spessartite-garnet, which, on account of its intimate association with the pitch-like mineral, could not be com- pletely removed. The latter in fact seems to have been derived from the garnet by some process of alteration. At Chargdon in the same district, a similar substance forms a matrix to the unaltered spessartite, from which it in this case also seems tio have been derived by alteration. The specific gravity of the specimen chosen was 3°22, whilst its hardness was 4. The analysis, carried out at the Imperial Institute, is given on page 908. In calculating this analysis into terms of its mineralogical composition, there is no alternative, since no braunite is visible, to taking out the small quantity of combined silica as spessartite, assumed to have the formula 3Mn0.(Al,Fe)03.38105. It is found that the remainder of the oxides cannot be combined to make manganates owing to a great deficiency in the amount of oxygen required for this purpose. The free silica must, of course, be regarded as present in the form of quartz. This must, however, be ina very finely divided condition as it is in no way visible in the specimen. The analysis can then be written as follows :— Specimen No. 1079. Apatite : 0°12 Calcite 5 0°25 Spessartite . : 3°70 Mng05 58 °50 Fe203 6°88 BaO . 0°78 CaO . 2°10 MgO . 0°15 H20 (combined) . 6°16 Quartz 3 ; “ = A iad. As205 3 : A 5 : : : 0005 Moisture. : 5 : 4 5 4°2] 100 °575 Subtract oxygen assumed. : 4 5 0°82 99 °755 12 1t67 ~ MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ PartTlI: it is interesting that the manganese oxides returned in the original analysis, after using 1°28% for the spessartite, should turn out to be so nearly in the proportions required for MngQs, 7.e. for MnygMnO;5, corres: ponding to psilomelane in which all the basic portion of the manganate is occupied by manganous manganese. If, now, we regard the BaO, CaO, and MgO, as impurities, and reduce the MngQ05, Fe 03, and H»)0, to molecular proportions, the following is the result :— 58 *50 Mn305 = ——- = ‘2554 =6 x ‘0426 229 6°88 Fee03 = ——- = ‘0480 =1 x *0430 160 6°16 He2O = —-— = °3422 =8 x °0428 18 These proportions work out so exactly that it seems probable that they correspond to the definite formula :— 6Mng305.Fe203.8H20. No analysis has been yet made of the apparently similar mineral occurring at Chargadon, so that it is not known if there is reallv a definite mineral corresponding to the above formula. In order, however, to dis- tinguish it, it will be well to give it a temporary name, and the best suited for the purpose is beldongrite, after the place where the mineral occurs, The mineral is, however, only to be regarded as a variety of psilomelane and is not easily to be distinguished from the lead-like varieties, such as the Avagudem specimen referred to above, except in its darker colour. It is to be understood that this is only a provisional name, which it may be necessary to discard in the future, if it be found that other specimens of apparently similar material do not correspond to this formula. The actual specimen is to be regarded as a mixture of beldongrite (71°54%%) with 17°72% of quartz and 3°70% of spessartite. Wad. According to Dana, in his System of Mineralogy, 6th edition, page 258, the term wad inciudes a number of mineral substances, such as bog-manganese, asbolite, and lampadite, that are not to be regarded as distinct mineral species, but rather ‘as mixtures of varisus oxides, chiefly of manganese (MnOy, alsc MnO), cobalt, copper, with alsc iron, and from 10 to 20 p. c. water.’ Characters. Cuap. IV. ] WAD. 117 The characters as given by Dana are as follows :— “In amorphous and reniform masses, either earthy or compact also incrusting or as stains. Usually very soft, soiling the fingers : iess often hard to H.—6. G.—3-0 - 4:26 ; often loosely aggregated, and feeling very light to the hand. Colour dull black, bluish or brownish black.’ There seems, however, to be every passage between psilomelane and wad, so that one often finds a specimen that one is doubtful whether to call psilomelane or wad. In naming Indian specimens of manganese-ores, the practice I have followed with regard to the uncrystallized or amorphous ores is to designate all those as psilomelane that in any way exhibit the characters of that mineral, the hardness especially being a criterion. If the mineral be a soft one, and show a finely crystalline structure, I have relegated it to pyrolusite, whilst if it show no signs of crystalline structure nor of the compact, firm amorphous structure of psilomelane, I have called it wad, this term being thus reserved for the indefinite mixtures so often found in manganese-ore deposits!. Some oi the chief localities for wad are the various deposits in the Vizagapatam district, where this substance has often been formed in considerable quantities by the replacement of the lithomargic matter accompanying the ore deposits. Wad is also extremely abundant in association with the manganese-ore deposits of the Sandur Hills and Mysore State. In the Sandur Hills it is best exposed in the deposits being worked at Ramandrug. Here it is intimately associated with psilomelane, the two together forming a very considerable proportion of the ores extracted. Itis evident from the mode of association of these two minerals that the wad is the first-formed mineral and that it subsequently gets converted into the psilomelane, pro- bably on the advent of a further portion of manganese in solution. The wad itself tends to be tabular or laminated in form, owing to its having been formed by the replacement of original laminated rocks, probably slates or phyllites. In colour it is greyish black, giving a soap-like streak that varies in colour from deep chocolate through brownish black to nearly black. It is fairly compact, but very soft, and usually . preserves the original siaty or phyllitic structure of the rock that Occurrence. 1 M. Gorgeu, in bis paper ‘ Sur les oxydes de manganése naturels *, Bull. de la Soc. fr. de Méneralogique, U1, pp. 25—28, (1890), regards wads or ‘ manganése liége ’ as true manganites. acid and hydrated, and conforming in certain cases to the formule :— 3(Mn02)RO.H20 and 3(Mn02)R0.3H20. He also says that wads are sometimes erystalline. 118 - MANGANESE DEPOSITS OF INDIA : MINERALOGY. { PartI: it has in ali probability replaced. Wad also occurs in the lithomargic rocks associated with the manganese-ore deposits at Ramandrug. In Mysore there is alsca great abundance ot wad associated with the manganese-ore deposits in each of the tour districts of Chitaldrug, Kadur, Shimoga, and Tumkur. It usually occurs associated with lithomarges and ochres in the soft altered rocks underlying the man- ganese-ore deposits. It is usually very light in weight, and, as a rule, is very fine-grained and compact, with a tendency to possess the structure of compact lithomarge. In colour it varies from almost pure black through deep brownish black to the brown of an ochre, there being a passage from one to the other, corresponding no doubt to changes in the relative amounts of manganese andiron. The streak is similar to that of the Sandur wad. Passages from wad to psilomelane can often be seen in the Mysore deposits. Another example of what may be regarded as wad is the specimen, of which the analysis is given on page 114, from Sontulai in the Hoshangabad district, Central Provinces, Other examples are to be found amongst the lateritic ores in most parts of India. In many of the most compact ores of the Nagpur-Balaghat area, Central Provinces, cavities or cracks are often found containing a small quantity of a deep brown velvety powder, which is also probably to be included under the term wad. The following two analyses of wads trom the Vizagapatam district were carried out by Messrs. J. & H. S. Pattinson of Newcastle-on-Tyne, on specimens carefully picked by myself so as tobeas far as possible homogeneous. Owing to the soft and crumbly nature of the specimens it was not possible to take their spicific gravity. Composition. Crap. IV. ] WAD. 119 Spec. No. A.221 Spec. No. 4.338 Garbham. Kodur, Brown wad, Black wad. Mn0O2 5 5 . : . . 58°12 61°38 MnO 4°14 3°59 Fe203 7°79 5°86 Al203 3°18 2 91 BaO 3 5 , ; - » 3 29 9°53 CaO . ; A : : : . 0°82 1°32 MgO . 3 ; - 5 : Onell 0°54 K20 . : : ' - mAb Alte) 0°61 Na2O A A : , 5 5 AOI 0°31 SiOz (combined) . - ; ‘ 3 185 3°00 SiO2 (free) . : : ; ; aoe LO 0°40 Sulphur. : . é : . 0°016 0048 P205 . é ; ; é ; - 0°198 0°261 As205. : A 5 ; “ - 0°026 0°012 CoO . , : : : - . O15 O'lu NiO . 7 : , 5 ; . Nil O°1e CuO . r - < é ONO 0°05 EbOm: : ; : : : . Nil Nil A NOW T 6 5 5 - a O25 0°15 ‘TiOg . 5 a 5 5 A . 0°06 0°02 Chlorine and fluorine. A ; . Wal Ni Combined water (H20) . : ; a (S10) 5°50 Moisture at 100° C. : : : . 155 4°35 C02 . ; . : : : . Nil Nil 99 "980 100 ‘041 Manganese (Mn). . : : - 39°95 41°59 Iron (Fe) ee ies OF hE Le Gag 4°10 Silica (total) s 6 5 : ; 1o°95 3°40 Phosphorus (P). é - 3 - 0°086 07114 It will be seen that both these analyses show a considerable proportion of combined silica. This, however, is not present in the form of braunite as is usually the case with Indian manganese-ores containing combined silica ; for the specimens appear to be homogeneous and certainly do not contain any visible crystalline constituent. Considering the mode of formation of these ores, namely by the replacement of lithomargic rock, or perhaps partly during the formation of the lithomarge from the original potash-felspar contained in the rocks associated with the manganese-ore deposits of this area, it seems probable that the combined silica is present 120 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: in the form of lithomarge or kaolin, and perhaps partly as potash-felspar only partially converted into kaolin. ‘aking the first analysis it is found that the composition can be represented as follows :— Specimen No. A. 221, Grthoclase i é ; ‘ F < i - 6°99 Albite . 3 : : 5 2 : Z 3 : 3°14 Kaolin 2°50 Apatite 0 °458 Psilomelane . 5 : : : : - 85°50 Quartz . Z ‘ 4 : : ps 5 3°10 Sulphur . ; - : ‘ : . : : . 702016 As205. : : : é : : ‘ - 0°026 Ti02 : : : ‘ ; ‘ 4 . 0°06 Moisture . : . - é : ; Sy ano. 103 °340 Oxygen assumed - : : ; : : zs - 3°36 99 °980 From the large amount of oxygen, namely 3°36, below that required for the formation of psilomelane, it follows that this wad is not a mixture of manganates (psilomelane) with the other constituents orthoclase, albite, kaolin, and quartz ; but that it is in all probability an indefinite mixture of oxides of manganese, iron, etc., with partly kaolinized felspar. In the same way the analysis of the Kodur wad can be calculated into a mix- ture of 6-429 of kaolin with psilomelane, the latter making up the bulk of the residue. But, as before, there is too large a deficit of oxygen, in this case 1-949%, so that this wad also is probably to be regarded as a mixture of oxides. On page 1090 is given an analysis of a specimen No. A. 228, collected at Garbham, that seems to be physically inter ediate etween psilemelane and wad. It is very porous and has a specific gravity of 4:08. It contains scattered through it a fair quantity of tiny specks of a magnetic mineral, which is probably manganmagnetite. As is show on that page, the analysis can be re-arranged so as to consist of 5°57°/, of kaolin, 10-45% of megnetite, and 82-21% of psilomelane, with no excess or deficit of oxygen. It is not certain, however, that this is the correct interpretation ; for the specimen may be only a mixture of oxides similar to the specimens noticed above. The chances, however, are in favour of its correctness,and it seems that this specimen is to be regarded as psilome- Jane just passing from the wad stage of indefinite mixtures. It is still soft, however ; but might have become harder later on by a more com- Cuap. IV. | ANKERITE. 121 plete incorporation of the manganates one with another. I have seen many examples of ores indicating that psilomelane may sometimes pass through the stage of loose aggregation characteristic of wad, and later become consolidated, perhaps through a more complete union of the oxides, with the formation of manganates. The characters of the two specimens of wad of which the analyses are given above are shown below. A. 221.—Garbham. This ore is dark grey-brown, and is lithomargic in aspect, being fine- grained and fairly adherent when dry. It is very soft (H=about 1) and has a dark brown streak. It is dull, except for little patches having somewhat of the lustre of graphite and possibly consisting of stained kaolinic films. A. 338.—K odur. This shows slickensided surfaces of a shining black colour. It some what resembles dirty coal, is more friable than A. 221, and has a nearly dead black streak. H=1. Both this and the preceding are light in weight, but are too friable for the specific gravity to be determined. Ankerite. Ankerite is a sub-species of rhombohedral carbonate, intermediate in Composition between calcite magnesite and siderite ; it has the chemi- cal formula CaCO,. (Mg,Fe,Mn)CO,. As the formula shows, it also con- tains a small quantity of manganese. Amongst the serpentinous crys- talline limestones exposed in a nala near Gowari Warhona in the Chhind- wara district, and of which an example is described in a paper on the petrology of this part of the district, I found one, 17°68 in the rock- register showing reddish brown plates of a rhombohedral carbonate enclosing, in a poikilitic fashion, rounded grains of calcite. The dark carbonate gives a faint reaction for manganese, and hence is probably to be regarded as ankerite : for it is doubtless also magnesian, since these serpentinous limestones almost invariably contain dolomite. 1 Ree. Geol. Sur. Ind,, XXXIII, p. 202, (1906). 122 MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ PartI1: R. D. Oldham says‘ ‘In the Tons below Anu there are exposures, of a brown ferruginous and dolomitic limestone, passing into crystalline ankerite in places which I have conjecturally correlated notwithstanding its lithological difference, with the Chakrata limestone.’ The Chakrata limestone is one of the pre-cambrian formations of the Himalaya and is found in Jaunsar in the Dehra Dun district. The specimen (6°403) of this rock is of a general buffish colour with grey specks. Its G.= 2:75. Other specimens in the Geological Survey collection labelled as ankerite were collected by Mr. Oldham on the ‘cart road below Sairi’ (6:440), and in the ‘Jumna valley about 3 miles above the bridge on the old Mussoorie road’ (6:438 and 6439). Both these places are in Jaunsar, the latter being in lat. 30° 33’, long. 78° 17. The Jamna valley Specimen is a fairly coarsely crystallized rock showing a rhombohedral carbonate of cream colour with a brownish tinge. The faces of the carbonate are often curved and exhibit a pearly lustre like that of dolo- mite. The rock contains a large number of small crystals of pyrite, often altering to limonite, and also shows brown bands, probably due to iron oxide. It has a specific gravity of 2:97 and reacts for manganese, iron, calcium and magnesium. Rhodochrosite. Although a rare mineral in India rhodochrosite is one of the minerals that, if found in quantity, constitute a valuable ore of manganese. It is a carbonate of manganese corresponding to the formula MnCO, with a theoretical percentage of manganese =47-83. The mineral is white, pink, or light brown, in colour, with a rather pearly lustre. Its streak tnisacedé is white. It is easily scratched by a knife (H=35 to 45), whilst it effervesces briskly with warm dilute hydrochloric acid, and is distinguished by this pro- perty, as well as by its inferior hardness, from rhodonite, which it other- wise resembles somewhat closely in external aspect. According to Dana G.=3'45 to 3:60 and higher. This ore has been extensively mined in the French Pyrenees and at a few other localities. Before itis charged into the smelting furnaces, however, it has to be roasted to remove the carbon dioxide, leaving an oxidized product intermediate in composition between MnO and Mn,0,, which would correspond, if the original ore were pure, to 1 Ree. G. 8. I, XVI, p. 194, (1883). — Crap. IV. ] RHODOCHROSITE. 123 a percentage of metallic manganese lying between 77 and 72. Hence it will be seen that although the original ore, even if pure, is considerably lower in its manganese contents than the oxidized ores that make up the whole of the ore exported from India, yet it may contain after roasting a considerably higher manganese percentage than the oxide ores. If any large supplies of rhodochrosite or carbonate ores should ever be discovered in India, it would of course be advantageous to roast them before exporting, on account of the great saving in freight charges that would accrue. As already mentioned, this mineral is a rare one in India; it has up to date been found only in the Chhindwara and Nagpur districts, both of them in the Central Provinces. In the Chhindwara district rhodochrosite has been found at two localities, namely Gaimukh and Devi. At Gai- mukh the rhodochrosite occurs in a rock composed of rhodonite and rhodochrosite with manganese-ore, the latter bemg probably braunite. The rhodochrosite is pale pink or pinkish white in colour, and occurs as small interstitial patches of pearly lustre between the rhodonite and braunite individuals, which form by far the larger portion of the rock. It also occurs in a rock composed of spessartite and rhodonite, but only in small quantity. At Devi it occurs sparingly as a rock composed of this mineral, with a larger proportion of rhodonite. Under the microscope it appears that rhodochro- site is not so quickly blackened to manganese oxides as rhodonite ; but it does also suffer this oxy-alteration. The rhodochrosite is not as a rule clear as seen under the microscope ; but is clouded, so that the cleavage is usually obscured. In one case where the cleavages were visible they were seen to be curved. In one case, also, signs of twinning were detected in spite of the clouding of the mineral ; but as a rule rhodochrosite does not seem to exhibit this phenomenon. The other microscopic characters that the mineral exhibits are absorption and a high birefringence, which do not of course enable one to distinguish it from the other rhombohedral carbon- ates. Like dolomite it does not stam when treated with Lemberg’s stain, at least as far as I have been able to ascertain on the clouded specimens I have been able to test. At Devi the amount of this mineral in the ore is inconsiderable, but at Gaimukh,when the ore-deposit is worked, it may be found that almost every piece of ore contains at least a small quantity of rhodochrosite. That this will not, however, be large in the aggregate, is shown by the analysis of a sample from this locality given on page 784, in which the amount of carbon dioxide is only 0:41%, corresponding to 1:07 of rhodochrosite. In several other of the analyses of manganese- Occurrence, 124 MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ Part 1: ores from the Central Provinces as carried out at the Imperial Institute, small quantities of carbon dioxide have been returned. In two cases, namely Pali (page 957) and Ghogara (page 964), the amounts of this constituent are larger than in the Gaimukh ore. This is, however, in all probability due to calcite and not to rhodochrosite ; for these ores occur in crystalline limestones. In the other cases, in most of which there is no indication of calcite in association with the ores, it may either mean that there is a very small proportion of rhodochrosite present, although this has not been detected in the ores of these places either macroscopically or microscopically or that carbon dioxide is in most cases really absent, the determination of its presence being due to experimental errors unavoidable when dealing with such small quantities of a substance so elusive as a gas. The one occurrence of this mineral in the Nagpur district is a doubtful one ; this is at Parsioni, where it seems to occur very sparingly in some of the rocks of the gondite series. The rock in which it occurs is composed mainly of rhodonite and spessartite, with a certain amount of amphibole, and sometimes orthoclase. The carbonate is to be seen clearly in micro- scope sections only, where it is sometimes intergrown with rhodonite, and sometimes right in the middle of the spessartite. CHAPTER V. MIN ERALOGY—continued. Silicates—Pyroxenes and Amphiboles. Blanfordite—Manganhedenbergite—Schefferite (?) & urbanite (?)—Pyroxenes of Vizagapatam—Colourless pyroxenes—J effersonite—Rhodonite—Manganese amphiboles —])annemorite (?)—Winchite—Juddite. Manganese-bearing pyroxenes. Amongst the manganese-bearing rocks in the Archean areas of Vizag- apatam, the Central Provinces, Jhabua, and Narukot, pyroxenes contain- ing a certain quantity of manganese are fairly common. There see us to be a considerable variety of such pyroxenes, owing no doubt to variations in the amounts of manganese and other constituents present : rhodonite is the species containing the most manganese, being manganese metasilicate ; whilst most of the other varieties probably contain but very small quanti- ties of manganese. Several of these are probably varieties new to science ; but, in most cases, they have not yet been closely examined, except in so far as is necessary in the course of the microscopic examination of thin slices of the rocks in which they occur. Nevertheless, I will give below the little I have determined with regard to these pyroxenes. Blanfor dite. The name of this variety has already been announced in a paper read The Kécharwahi occur. Defore the Mining and Gclogical Institute of orto India, and I cannot do better than quote here what was published in the Transactions of this Institute’. The typical mineral was found in the Kacharwahi quarry, Nagpur district. The account of this mineral given in the above-cited publication is as follows :- «It is notable for its strixing and beautiful pleochroism, which even in thin sections is— a—rose-pink, b=bluish lilac, c=sky-blue. ‘In thick sections the a and b axis colours are deep carmine and very rich sky-blue respectively. When fresh, the pyroxene is deep crimson as seen in hand specimens, but it is often altered so as to be chocolate-brown in colour. The mineral is mono- Original account. 1 Vol. I, p. 78, (1906). 126 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ ParTI: clinic, with a small angle of extinction. The crystals noted below show three forms, the prism, clino-pinacoid and clino-dome, and sometimes exhibit basal parting planes best seen in thin sections under the microscope. In sections at right angles to the acute bisecrix a figure can be obtained, but points of emer- gence of the optic axes lie outside the field of view of the microscope. The specific gravity (as determined with some minute fragments and Sonstadt’s solution) is 3:15. Before the blowpipe the mineral fuses easily to a black bead, gives a marked sodium flame and with fluxes gives indications of small quantities of manganese and iron. It occurs partly as a pyroxene-braunite-rock with inter- titial apatite, and partly in aggregates and scattered crystals up to an inch long in a rather coarsely crystalline albite-rock. I propose to call this mineral blan- fordite, after the late Dr. W. T. Blanford.’ ‘ Since this was written I have been able to pay a second visit to this locality and obtain a further supply of the mineral. I have at present little to add to the above account, except that in some of the thin sections of the rocks containing blanfordite I have found an amphibole of some- what similar pleochroism that is likely at first to be confounded with the pyroxene unless the considerably lower index of refraction of the amphi- bole be noticed, or a section be hit upon that shows the characteristic cleavages of the amphibole group (see juddite). Moreover, the albite- rock mentioned above frequently contains microcline and sometimes a Crystallogra phic little quartz. In figures 11 and 12 illustrations characters. are given of two crystals of this mineral. Figure 11, showing the forms m (110), b (010), and e (011), represents the common habit of the mineral, the crystals of this habit ranging ; Fig. 11—Blanfordite. Fig. 12—Biarfordite. from perhaps} inch in diameter up to the size figured. Figure 12, Cuap. V. ] BLANFORDITE. 127 showing the extra facea(100), represents only one crystal, which is about 2inches long in the direction of the @ axis. With regard to the systematic position of this pyroxene it is at present impossible to speak with any certainty, since the mineral has not yet been analysed ; but as it seems to have some resemblance to the pyroxene from St. Marcel known as violan, which has been shown by Penfield’ to be a variety of diopside, it seems probable that blanfordite will also turn out to be related te diopside. In this same paper, on page 292, Penfield describes another pyroxene, which shows a very faint pleochroism in very pale rose and very pale blue. An analysis of this pyroxene shows 058% MnO and 1:06% Mn,O, and Penfield considers the pyroxene to be composed of about equal parts of diopside, jadeite, and acmite, with 3-0% of the molecule NaMn(Si0),. What is probably blanfordite was also found at Ramdongri, also he Rémdongri otcur- i” the Nagpur district, where it occurs in the rence. manganese-ore body ina patch of a rock that is probably to be regarded as a granitic intrusive. This rock, noticed on page 857, is of rather fine grain and is composed of microcline, quartz, plagioclase, and perhaps orthoclase with some apatite, zircon, and brown mica. In sections of about the same thickness, however, the depth of the colour in the Ramdongri blanfordite 1s not so deep as in the Kacharwaéhi mineral. In some sections the c axis colouris greenish blue instead of pure blue. Monoclinic pyroxenes having exactly the same type of pleochroism, Wie Kéjlidong@t oceurs OBlY in much paler tints, also occur at rence. Kajlidongri, Jhabua State, and Jothvad, in Narukot State. It isnot known at present whether these minerals are the same as the Kacharwéhi pyroxene, but as they exhibit the same type of pleochroism, which can for convenience be called the blanfordite type of pleochroism, they can be provisionally included under the term blan- fordite. The blanfordite of K 4jlidongri occurs at the northern end of the deposit associated with the winchite-bearing schists mentioned later on page 150. These schists are to be regarded as the product of the metamorphism of manganiferous sediments, the typical rock thus pro- duced being composed of winchite, calcite, braunite, and quartz. 1 Amer. Jour. Sci., XXXVI, page 293, (1893). 128 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Parr]: Sometimes this rock contains pyroxene in addition; but the latter mineral occurs much more frequently in those varieties of the schists that are free, or nearly so, from calcite. Its commonest mode of occurrence 1s in the form of greenish patches in a white fine-grained quartz-rock usually containing winchite in addition. Sometimes these patches are more of the nature of cloudings and sometimes they take the form of rosettes, in which case the periphery of the rossette is com- posed of lilac winchite. Neither rosettes or cloudings are usually more than } inch in diameter. Under the microscope the cloudings are seen to be indefinite aggregates; whilst the rosettes show radiating prismatic pyroxene individuals in the interior of the rosettes, with winchite prisms in parallel growth with them at the periphery. It is interesting to note that the orientation of the two minerals is nearly the Same as regards their pleochroism, what differences there are being due to the different extinction angles of the two minerals. Thus the axes corresponding to blue in the two minerals are nearly parallel, whilst the pyroxene showslilac with a tinge of brown at the same time that the amphibole showslilac. The extinction angle of the pyroxene seems to be smallin value. It will be seen that the colour of the Kajlidongri blanfordite as viewed macroscopically is slightly different to that of the Kaécharwéhi mineral and that therefore one cannot be certain that it is the same mineral. It may, however, be that the difference is due simply to a slight difference in the amount of manganese present in the mineral. It will be gathered from the above that the blantordite of Kachar- whi and Rémdongri occur in rocks that are The Narukot occurrence. robably of igneous origin, whilst the pyroxene from K4jlidongri, exhibiting the blanfordite type of pleochroism, occurs in a rock that is in all probability a metamorphosed sediment. At Joth- vad in the Nérukot State, Bombay, pyroxenes exhibiting this type of pleochroism occur in both an igneous and a metamorphic rock ; the latter is probably a metamorphosed sediment belonging to the gondite Serles as represented at this locality ; whilst the igneous rock is intrusive in the rocks of this series, being an apophysis from the granite surrounding the hill in which these rocks occur. The granitic vein doubtless obtained the small proportion of manganese it contains, by absorption from the man- ganiferous rocks.at the time of its intrusion into them. The granitic ven consists of microcline, with a smaller proportion of oligoclase, orthoclase and quartz, with a slightly manganiterous garnet and a pyroxene. The latter occurs in small stumpy prisms of octa. Caap. V. } BLANFORDITE. 129 gonal and hexagonal cross-section with the angles of a pyroxene. These prisms vary in length from } up to nearly } inch, and are dark brown with a reddish tinge. Under the microscope they exhibit the following pleochroism scheme :— i=rose, b—pale vioiet-brown to lilac, c=greenish blue to pale blue. In one case the a axis colour seemed to be green without any tinge ot blue, so that, the other axis colour visible being pink, the mineral might be mistaken at first sight for hypersthene. That it cannot be this, how- ever, is shown by the fact that the extinction is not straight, being 32° in the section that shows the green colour best. Moreover, the ¢ axis colour in hypersthene corresponds with the vertical crystallographic axis ¢, whilst in this mineral vertical sections often show the axis approximating to parallelism with the vertical crystallographic axis The angle a» ¢ varies from 0° to 53° and the angle ¢ 4 ¢ from 37° to 68°. The index of refraction is high and the birefringence consider- able, the polarization colours being sometimes as high as green of the second order, in sections in which the felspars polarize in greys. The specific gravity of the mineral is somewhat higher than that of the typi- cal blanfordite of Kacharwahi, being determined as 3°264 and 3°268 on two separate specimens by means of Klein’s heavy liquid. The value of this constant can, therefore, be taken as 3°26 to 3°27 for the pyroxene from this rock. The mineral gives a distinct, but not very strong, re- action for manganese. The metamorphic rock in which pyroxene exhibiting the blanfordite type of pleochroism occurs is a banded one, of which some layers have the outward aspect of a hiotitic sandstone of rather fine grain, whilst others suggest a very fine-grained quartzite. Under the microscope the ‘ biotitic sandstone > is seen to be composed of quartz, microcline, apatite, black manganese-ore, an orange-coloured mica, and a vyroxene. The last occurs in ragged plates often intergrown with mica, whilst some plates form a sort of network enclosing in its meshes rounded prisms of apatite with some quartz. The pleochroism shows that 4 is pink andc blue, whilst the one extinction angle measured was c a c= 19° Asection of the bands resembling quartzite coxsisted essentially of a mosaic of quartz with a fair abundance of pyroxene, I K 130 MANAGNESE DEPOSITS OF INDIA : MINERALOGY. [ Part I: The latter was pleochroic in very pale pink and green, corresponding to a and ¢c respectively. The extinction angle a»¢ varies from 14° to 47°. In places the green tint looks distinctly bluish, and, in fact, when the tints are so pale, it is often very difficult to determine whether th: ¢ axis colour is blue or green. With the quartz polarizing in grey and white of the first order, the pyroxene polarizes in orange and red of the first order and purple of the second. Comparing the properties of the various varieties of pyroxene noticed in the preceding paragraphs it seems that the type of pleo- chroism is approximately the same in all, namely :— a= pink, b = lilac, c=blue, the depth of these various tints varying very much in the pyroxenes of different localities. The above scheme, which is that of the typical guineral of Kacharwahi, is subject to slight variations in the pyroxenes of other localities. Thus the lilac colour corresponding to the b axis may have a tinge of brown in it. causing this colour to approximate to the characteristic colour of titaniferous augite, whilst the blue colour of the ¢ axis may have a greenish tinge in it, or may even be quite green, the latter phenomenon being noticed both in the igneous variety of Jothvad and in the variety, also igneous in origin, found at Ramdongri. The cause of the differences in the depths of the colours of the varieties from different localities may be due to differences in the amounts of manganese present, as also may be the differences in the values of the angle a4 ¢. But these poiits can only be settled by the isolation and chemical analysis of the different varieties; until this is done it is not possible to say if we are dealing with only one variety of pyroxene of slightly varying composition, or whether more than one mineral has been included under the name blanfordite. If the latter be the case and later it be found necessary to give a separate name to some of the varieties, then the name blanfordite will be reserved for the variety for which it was first proposed, namely that of Kacharwahi. Manganhedenbergite. Hedenbergite is a calcium-iron pyroxene of the formula CaFe(Si0g)s. When a certain proportion of the iron is replaced by manganese Cuap. V. | | MANGANHEDENBERGITE. Fiat b, 131 the mineral is called manganhedenbergite and the formula can then be written as Ca(Fe,Mn)(Si03)0. I found a specimen of this mineral loose in a pit that had been excavat- Occurrence and charac. 4 in the crystalline limestone at Junawani in ters. the Nagpur district. It had evidently been derived from the limestone, from which it had become separated, apparently through the decomposition of the enclosing rock. The speci- . men is a piece of one crystal about 24 inches long at right angles to the basal parting, and 2? inches by 13 inches across the longest and shortest measurements of this parting. The parting is well-marked and shows a vitreous to pearly lustre. Under the microscope it is seen to be the result of the formation of very thin twinning lamelle. The lustre on rough cleavage fractures parallel to the vertical axis is resinous- vitreous and the colour greenish brown. In one place where the pyroxene is transparent the true colour is seen to be sherry-brown There are often a large number of small copper-coloured mica scales, intercalated along the well-marked prismatic cleavages so that their basal cleavage planes are parallel to the vertical crystallographic axis of the pyroxene. At one end the specimen passes into crystalline limestone in which there is a little spessartite. The hardness of the pyroxene is between 5 and 6. Under the microscope the mineral shows well-marked basal partings and much less well-marked prismatic cleavages in sections parallel to the vertical axis of the mineral. But in the basal sections the characteristic prismatic cross-cleavages of a pyroxene are well seen. Extinction angles (¢ a ¢) on the sections prepared measured up to 333°, but it is not certain that any of these sections were truly parallel to the clino- pinacoid. In thin sections the mineral is colourless, but when the sections are thicker the colour is pale brownish. The mineral often shows various inclusions, particularly of mica, but sometimes of spessartite. Con- sequently, it was very difficult to prepare a pure sample for analysis, and it is probable that the sample analysed was not quite free from these inclusions ; but their amount cannot have been sufficient to account for nearly the whole of the manganese present. Hence there can be little doubt that the mineral really is manganhedenbergite and nct heden- bergite containing inclusions of mangeniferous minerals. The specimen analysed was found to have a specific gravity of 3°31. The analysis was carried out by I K 2 Composition. 132 — MANGANESE DEFUSITS OF INDIA: MINERALOGY. [ Part I: Sub-Assistant S. Sethu Rama Rau in the Geological Survey labor- atory, with the following result :--- Specimen No. 1061. CaO ; 4 P : 5 . 24°88 FeO ‘ 3 ‘ , : : B dleHO} MnO ; ; A a < 5 ‘ 5°84 MgO : c c : : 5 PHA BaO 7 ; 3 A 3 OR AlsOs 4 F ; 5 ; ° - 0°48 SiO2 ; 3 ; - 2 ; -. 50°96 Combined water 3 ; ‘ : - 1°09 Moisture at 100°C. . 3 ‘ g - 0°85 99°92 In this the iron and manganese have been assumed to be in the protoxide condition ; for the state of oxidation was not determined, owing to the difficulty of obtaining a sufficient quantity of the pure mineral. The theoretical composition of hedenbergite is as follows :— CaO . ; ‘ j : . ee 2252 FeO . ‘ : 4 : 5 z » 29°4 SiOe. ° - ‘ A ; 3 . 48°4 From this it will be seen that the Indian specimen corresponds to hedenbergite with a considerable proportion of the iron protoxide replaced by other protoxides ; these latter are the MnO, MgO, BaO, and a small proportion of the CaO, there beimg an excess of this last constituent over that required for the CaO group of the mineral. Althovgh only one large specimen of this mineral was found, it is not improbable that the small granules of pyroxene occurring in the crystal- line limestone at this locality are also hedenbergite, though perhaps not always manganiferous. Brown and Yellow Pyroxenes (Schefferite and Urbanite). In the Indian manganese-bearing crystalline rocks of Archean age there are several occurrences of pyroxenes showing some tint of brown in the hand- specimen and shades of yellow and pale brown under the micro- scope. Pyroxenes of these tints have been found in the igneous rocks of the kodurite series in the Vizagapatam district, Madras, where they especially affect the manganese-pyroxenites ; whilst in the areas where the gondite series occurs such pyroxenes occur both in igneous rocks intrusive in the gondite series (in the Bhanddéra and Chhindwara districts, Central Provinces), and in the metamorphic rocks of the gondite Occurrence. Cuap V. ] SCHEFFERITE AND URBANITE. 133 series (in Jhabua and Narukot, in Central India and Bombay, respec- tively). As the rocks in which they occur show considerable variety as regards composition, it seems probable that the brown pyroxenes con- tained therein will also be found to vary considerably in composition and consequently in physical properties. In no case have I yet been able to carefully examine these pyroxenes either chemically or physically. In the case of the Vizagapatam examples, however, this would not be a matter of great difficulty, as the granules of the minerals are often of sufficiently large size for their extraction to be a matter of comparative ease. In the case of the igneous rocks containing these pyroxenes in the Central Provinces their separation for examination would also be fairly easy : but in the metamorphic rocks it would be quite another matter; for the pyroxenes usually occur in small granules very intimately associated with the other constituents of the rocks in which they occur, so that they are not as a rule conspicuous in hand-specimens. As far as I can tell from the published literature available, these minerals will probably be found, at least in some cases, to correspond more or less closely with already-described varieties of pyroxene. In most cases I have not proved that these minerals contain manganese ; but considering the fact that they occur in manganiferous rocks and that those examples I have tested have given reactions for this element, sometimes weak and some- times marked, it seems probable that they are all more or less mangani- ferous. There are two known varieties of pyroxene that are both manganiferous and of brown and yellow tints. These are schefferite and urbanite. The composition of these two minerals is shown below :— Composition. Schefferite . : . (Ca,Mg)(Fe.Mn)(Si03), Urbanite. P . (Ca,Mg)SiO3 + 2NaFe * (Si03)2 (diopside) (acmite) In two analyses of the latter mineral !, 1:73 and 6°71 per cent. of MnO are returned, the MnO presumably replacing some of the protoxides in the above formule. Analyses of schefferite quoted by Dana show 6°20 to 8°32 per cent. of MnO. The essential difference in composition between the two minerals seems to be that urbanite, in addition to containing the ordinary molecule. in which the oxides are all protoxides, as in diopside and schefferite, also contains the acmite molecule, in which a_ con- siderable proportion of soda is accompanied by ferric iron. Hence, as Schefferite and urbanite. 1 R. Mauselieus, quoted by Sjogren. Bull. G. Inst. Up-ala, U1, p. 77, 106, (1894), [Dana]. 134 MANGANESE DEPOSITS OF {NDIA: MINERALOGY. [ Part I: the percentage of manganese is roughly the same in the two minerals, the best way of distinguishing between them would seem to be to test them for sodium. A marked reaction for this element might then be taken to show that the mineral was urbanite, whilst failure to obtain this reaction to any but small extent might be taken to indicate the min- eral to be schefferite. The above distinction would, however, only hold on the assumption that all the Indian yellow or brown manganese- pyroxenes must be either one or the other of the two minerals named above. This, of course, by no means follows ; so that although the Indian brown and yellow manganese-pyroxenes can be provisionally divided into these two species by means of the sodium test, it will need the complete chemical analysis of various picked specimens to definitely settle this question. The characters of these two minerals that are of importance in addition to the chemical composition are given below, and were extracted from Dana’s System of Mineralogy. Schefferite :—Cleavage distinct, prismatic. Colour yellowish brown to reddish brown. Optically+. Bx, »c=eveé 44° 2531. Schefferite is found at the Langban manganese mine, Sweden. The variety known as iron-schefferite, on account of the large amount of FeO present replacing MgO and CaO, is black in colour when from Pajsberg, and then has ¢*c—49° to 59° for different zones jn the same crystal. The variety from Langban is brown and has ¢c ¢=69°. Urbanite :—Cleavage, prismatic (m) distinct; (c) less so. H.=5 to 6. G.=3'52 to 3°53, colour brownish black to chestnut-brown. Strongly pleochroic, the following being the scheme of pleochroism :— a=brown ; b=yellow-brown ; t=yellow. aAé =16° to 22°. Itis found at the manganese mines of Langban and Glakiirn in Sweden. In the following table I give those characters that have been ascer- tained for the yellow and brown pyroxenes of the rocks associated with or forming part of the gondite series. Since I have inserted in this list all the occurrences I have noticed of such pyroxenes in these rocks, it will be understood that they are of comparative rarity, considering the large number of occurrences of rocks of this series that are known. Of these occurrences, 1, 2, and 4 are in rocks that are in all probability of igneous origin, whilst 5, 6, and 8 are probably of metamorphic origin. No. 3 can be doubtfully regarded as of metamorphic origin, as it 1 R. Mauzelius, quoted by Sjogren, Bull. G. Inst. Upsala, IL, p. 77, 106, (1894), [Dana J Cuap. V.] SCHTFFERITE AND URBANITE. 135 seems to form part of the gondite series. In No. 7, Jothvad, the yellow pyroxene occurs in a portion of the rocks of the gondite series that has been included in the granite surrounding the hill in which these rocks occur; this rock is best considered as a contact rock formed by the interaction between the granite and the metamorphic rock it has picked up. As regards the pleochroism it must be noticed that the axis colours have been determined on sections in thin slices of the contaiming rocks. These sections necessarily cut the pyroxene in various directions and it is not usually possible to determine exactly what this is. Consequently in testing with a quartz wedge I have simply recorded the colour corresponding to the direction of great- est and least elasticity as 2 and c respectively, choosing for this test only those sections that seemed to be cut fairly clese to planes parallel to the vertical crystallographic axis. When this section happened to be clino-pinacoidal then the colours recorded would be those really corresponding to the a and ¢ axes. When however the section happened to be parallel to the ortho-pinacoid, then of course one of the axis colours recorded would be b, whilst the other would be compounded of both the a and ¢ axis colours. Im such a case, however, the extinc- tion would be straight; to avoid this confusion I have chosen in all cases those sections giving the largest extinction angles and therefore those approximating most closely to the clino-pinacoid. The 6 axis colour must in all these cases be very similar to the colours recorded for the other axes, as it would otherwise be noticeable. From the figures given above for schefferite and urbanite it will be seen that the values of the extinction angles for these two minerals are as follows :— Schefferite. . -. . aA¢=21° to 45%, Urbanite . - ‘ - BAe =16° to 22°; whilst in the examples in the table the value of this angle varies from O° to 60°. Probably in most cases these Indian pyroxenes are monoclinic, but in the case of the Kajlidongri mineral it seems possible that it is orthorhombic. Tt is difficult on such insufficient data to specify any particular examples of the above as either schefferite or urbanite, but perhars the Sitapathir specimen may be regarded as urbanite on account of its reaction for sodium. [ Parr I MINERALOGY. . . ANGANESE DEPOSITS OF INDIA + £ qeqoig ROR 8 4S] oso ou0 UT | | | ‘19p10 | | o9f OF dn=9 Vu pur osvavo[g smmd3yN jo oyIeN “4 | “oS P= 7 ‘4x0 Joyjoue | ‘squly Ur “(6=9VK YstuMosq 07 yst esvo = =ouo-— uy: -MOTaA oped Aso, “UMOTG YSTMo[[oA *,09 osvo ouo =| pur Yystudods 07 ul ynq ‘,0p JO | UMoIq s0[eq==3 uMoIq YySIT—v “W001 JO esuty sowmmoulos ‘ey AQ pourw409z0 ‘soto -yed osura¢ *MoT[aA sno -UISOL JSUT ‘asura0 YStuMorg. 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JO Yor popurg ‘Lousyds ‘agiyede ‘aqiq[e ‘ose -oyao = Sautpoo.zorur] -ol UL VASIG yoor-redsjoj-ouoxosk | yoor -ourpoOdorue ZyaeND —o}qanssods-onaxortg ayRUsog ayy VUseg -Aaquog ‘992849 40H “NIN pyar ’g -Lequiog ‘ayeqg 4OH -TUBN “PRANIOL *L af Oa 9 ‘oyeig wnqeyer ‘asuopyley “9 0 ‘07849 -enqeye ‘1usu0pyly yy “¢ ‘d ‘0 4ouysp vAIBApPUIy YS ‘euvyq Wory “F ‘d ‘) ‘qouaystp Barpp “unt “IPMS “f ‘d 0) “yoy “Sip vaypueyg ‘mygedezg “Zz ‘d 0 ony vispueyg ‘equinsoy *] “stp ‘uotpisodmoy “punoz ory ut yooyy ‘saudas apypuoh ay) ypin payproossy sauacoshd unosg pun nojoh ayz fo sarzsado ty ‘OL JIAvV, *AppRoO'T Cyap. V.] THE PYROXENES OF THE VIZAGAPATAM DISTRICT. 137 The Pyroxenes of the Vizagapatam District. In the foregoing table I have not included the brown pyroxenes of the Vizagapatam district, where they are of much more common occurrence than in any of the other manganese areas, no doubt on account of the occurrence of the rocks I have designated manganese- pyroxenites. But with most of these I have done little more than determine the fact that they are pyroxenes. Amongst the pyroxenes of this district there at least three varieties or species, and perhaps four. that are probably manganiferous ; for each of them may be found in every stage of blackening and alteration to manganese-ore. One of these is rhodonite and will not be considered here, but under the heading of that mineral. Of the others the best marked is a rich brown to orange-red variety forming by far the larger proportion of the manganese-pyroxen- ites of Taduru. This mmeral occurs in rounded grains up to } inch across, and under the microscope is brown in thick sections and pale yellowish in thin, the pleochroism being very weak. Measurements of the angle ¢ “ ¢ vary from 8° to 45°. Prismatic cleavage is often marked. The! mineral gives a strong manganese reaction. What is probably the same pyroxene occurs at Sandapuram and Perapi. Brown pyroxene. The second pyroxene is one that is a deep green as seen with the unaided eye, sometimes being even greenish black. It is found at Taduru in association with the pyroxene mentioned above, and also at Kodur, Chintelavalsa, and Perapi. Under the microscope the mineral usually exhibits some shade of brownish green when in thick sections, whilst in thin sections it is pale greenish to colourless. In one of the Kodur specimens the extinction angle ¢“ ¢ ranges up to 35°, referred to the often very well marked prismatic cleavage traces. Sometimes the colour in thin slices is pale yellowish rather than greenish. In one such case the mineral was faintly pleochroic, a being colourless, and ¢ pale yellowish. Green pyroxene. Besides these two pyroxenes there seems to be a third, which is not green or brown as seen microscopically, but an intermediate colour, namely dark This variety is also found at Tdduru, in prismatic crystals up to 1 inch long. In very thick sections the colour is seen to be a pale brownish, but in thinner sections the colour seems to be a pale greenish. This variety is faintly pleochroic, and exhibits very oblique extinction. It is also found at Kantikapilli. Brownish green pyroxene. brownish green. 138 - MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: It is uncertain whether these are three distinct varieties of pyroxene as detailed above, or only three stages in a series of pyroxenes gradating one into the other. When the rock-slices are ground very thin, then they all become very pale in colour so as to look colourless at first sight. When so thin it is often very difficult, in fact almost impossible, to distinguish them from rhodonite, which is also colourless in thin sections and often occurs in the same rocks. When the rocks are fresh this is a matter of little consequence, because the pink colour of the rhodonite in hand-specimens at once distinguishes it from all the others. Colourless pyrexenes. In some of the rocks of Jothvad in Naérukot there are pyroxenes that under the microscope are seen to be colourless, but which do not indicate in the hand-specimen that they are rhodonite, the pink triclinic pyroxene, which is also colourless under the microscope. The rocks in which these occur are very fine-grained, one of them being composed of quartz, rhodonite (?), spessartite, sphene, and a rhombohedral carbon- ate, probably calcite. The pyroxene is practically colourless, shows marked cleavage and extinction angles up to 38°. Jt may be only one variety of the yellow pyroxene of this locality. The other rock in which such a pyroxene occurs is composed largely of piedmontite, with a good quantity of spessartite and apatite. The pyroxene is colour- less to pale pinkish and in one case gave an extinction angle of a » c=42°. This might be a variety of the blanfordite type of pyroxene, practically free from manganese. It is not known if these colourless pyroxenes are manganiferous or not. It does not perhaps necessarily follow that, because they occur in rocks that are themselves strongly mangani- ferous, therefore they contain more than a trace of manganese. Jeffersonite. This is a manganese-zinc pyroxene found at Franklin Furnace in New Jersey, U.S. A. It is practically a zinc variety of schefferite. The only record of this mineral in India is to be regarded as very doubtful, especially as there is, as far as is known, no specimen extant of what was originally determined as jeffersonite. This record is contained in the catalogue of the Reverend Mr. Muzzy’s collection of Madura rocks and minerals! ; the locality is given in J. H. Nelson’s “The Madura Country ’ 1 E. Ralfour, Catal. Govt. Cent. Museum, Madras; ‘Madura, its rocks and Minerals’, p. 4, (1855). Cuap. V.] RHODONITE. 139 p. 166, (1868), as near Mankulam, about 11 miles N.-E. of Madura. Balfour’s list also gives a second locality, namely Manapara. Rhodonite. This mineral is a pyroxene belonging to the triclinic system. It is a metasilicate of the composition represented by the formula MnSi0z, which corresponds to a theoretical maximum % of manganese of 41-86. Frequently a small portion of the manganese is replaced by iron, calcium, or magnesium, and in rare cases by zinc. When these replacing constituents reach considerable proportions then a different name is sometimes given to the minera'. Thus when high in lime the mineral is called bustamite, and when high in zinc it is known as fowlerite. A separate name has not been given to the variety high in iron, whilst rhodonite containing large quantities of magnesia has not yet been recorded. The characters as given by Dana in his ‘ System of Mineralogy’, page 379, are as follows :— Found either in crystals or massive, or as embedded grains. Cleavage perfect, prismatic (m and M); ¢ less perfect. Fracture conchoidal to uneven; very tough when compact. H.=—5°5 to 65. G.=3-4 to 3°68. Lustre vitreous ; on cleavage surfaces somewhat pearly. Colour light brownish red, flesh-red, rose-pink; sometimes greenish or yellowish, when impure ; often black outside from exposure. Streak white. Transparent to translucent. Characters. Under the microscope the mineral is colourless and shows well- marked prismatic cleavages appearing as two series crossing at angles approaching a right angle (mM =92° 283’) in sections at right angles to the vertical crystallographic axis (see fig. 3, Plate 12), and as a series of parallel traces in sections parallel to the vertical axis. With regard to these parallel cleavage traces the extinction is very variable and usually very oblique. Dana does not mention any cases of twinned crystals of thodonite. J have not yet seen any Indian specimens of rhodonite exhibiting definite crystal faces and consequently have not in this way recognised any cases of twinning. Under the microscope, however, I have not infrequently found examples of this mineral showing well- marked twinning, this being sometimes polysynthetic. Rock sections from Asalpdni (Bhandara district), Devi (Chhindwara district), Jothvad (Narukot), and Manegdon (Nagpur), exhibit this phenomenon. In the Microscopic aspect. 140 | MANGANFSE DEPOSITS OF INDIA: MINERALOGY. [Parr I: Manegdon example there is one section at right angles to the prism zone, showing two thin twiined lamelle bisecting the angles of the crossed cleavages. They indicate that the direction of twinning is parallel to b. Other microscopic characters worth noticing are the low birefringence, so that the colours are of the first order in thin sections; and the absorption to be seen on relating the polarizer. Of the microscopic characters given above for this mineral the most serviceable in identifying it are its rose- pink colour; its granular crystalline charac- ter, often causing it to resemble in appearance a crystalline limestone, except for its colour; its hardness, so that it is scratched by a knife with difficulty or not at all; its extraordinary toughness when massive, as nearly all the Indian specimens are, so that it is very difficult to prepare good hand-specimens of the rhodonite-rock ; and lastly its high specific gravity. As chemical tests, reactions for manganese and silica must be relied on. At first sight it might be confounded with rhodochrosite on account of its crystalline character and pink colour. The distinction between these two minerals is, however, easy to make, because rhodochrosite, being a carbonate, effervesces when heated with dilute hydrochloric acid, and is also much softer than rhodonite, being easily scratched with a knife. The Indian rhodonites are not, however, always rose-pink in colour. At Guguldoho and Sitagondi, both in the Nagpur district, greenish grey rhodonite is to be found in massive pieces, whilst at Jothvad I found brown rhodonite, both these varieties being apparently fresh. It must be admitted that these two varieties have not been chemically examined, so that the deduction based on their general aspect and appearance under the microscope may be incorrect. When altered, rhodonite may show every shade of chocolate and dark brown up to brownish black and black. When Mallet’s book on the Mineralogy of India was published in 1887 as Volume 4 of the Manual of the Geology of India, only two occurrences of this mineral in India were known. One of these was a specimen obtained by Mallet from a lohari, who found a quantity of it a foot or two below the surface in the southern part of the Mirzapur district, United Provinces. The other was the occurrence of rhodonite in association with braunite at Mansar near Ramtek in the Nagpur district, described by Mallet in a paper in the Rec. Geol. Sur. Ind., XII, page 73, (1879). An examination of the specimen in the Museum from Identification. Occurrence of rhodonite. Crs. V.} RHODONITE. 141 this locality, Jabelled as braunite with rhodonite, has shown that what Mallet took to be rhodonite is really orange spessartite, patches of which occur in the midst of the manganese-ore in the specimen exhibited. The description of the mineral in the paper itself also points to spessartite rather than to rhodonite. Consequently the Mirzapur occurrence must be taken as the only one known until Mr. C. S. Middlemiss discovered loose blocks of this mineral, blackened externally, scattered on the road from Burjavalsa to Chintelavalsa, near Taduru, and near Thonaum, all of them in the Vizagapatam district just on the outskirts of the Eastern Ghats. This was in the field season of 1903-1904. In the same field season I found the same mineral first at Ramdongri and then at many other places in the Balaghat, Bhandara, Chhindwara and Nagpur dis- tricts in the Central Provinces. The next season I was able to visit the occurrences noticed by Middlemiss, with the exception of Thonaum, and find the mineral in stu : in the same season I also found the mineral in the Ganjam district, Madras; in Jhabua State, Central India, and in Narukot State, Bombay. The following is a list of all the known occurrences of this mineral in India :— Bombay — Narukot State :—Jothvad. Central India— Jhabua :—Kajlidongri. Central Provinces — Balaghat :—Chikmara, Sonegaon, Thirori. Bhandara :—Kurmura, Asalpani I, Asalpani 1. Chhindwara :—Alesur, Bichua, Devi, Gaimukh, Ghoti, Wagora. Nagpur :—Peldongri, Chargaon, Guguldoho, Junawani, Kandri, Khandala, Mandri, Mandvi Bir, Manegaon, Mansar, Panchala, Parsioni, Ramdongri, Risara, Satak !1, Sitagondi, Waregaon. Madras— Ganjam :—Nautan-Barampur. Vizagapatam :—Chintelavalsa, Kantikapilli, Taduru, Thonaum. In Bombay, Central India, and the Central Provinces, the rhodonite occurs in rocks of the gondite series, and is hence in all probability the product of the metamorphism of manganiferous sediments in the way explained on page 290. In Ganjém and Vizagapatam the rhodonite occurs in rocks that may be the result of solidification from the molten condition. That the metamorphic mode of formation is the charac- teristic one is shown by the frequency with which this mineral occurs in the rocks of the gondite series ; on the other hand, I have never found it in the rocks intrusive into the gondite series, where one might expect to find it if the mineral were at all commonly formed by solidification from fusion. This same tendency is shown by the fact that rhodonite 142, MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: is never found inthe typical members of the kodurite series of Vizaga- patam, but only in those varieties I have designated the manganese- pyroxenites (see page 249). These, however, are nearly always found apart from the typical kodurite rocks, so that at first sight it might be thought that the mere fact of their containing rhodonite, considering what has been written above, might be taken to indicate that these manganese-pyroxenites are also of metamorphic origin and form a distinct series from the igneous kodurite series. It seems more probable, however, that the manganese-pyroxenites are also of igneous origin, since they are sometimes found in association with the typical kodurite rocks, as at Perapi and Kodur, for instance; and that the absence of rhodonite in the typical kodurite rocks is due to the fact that rhodonite requires about 42 per cent. of manganese for the formation of pure MnSiOs; and that when many other constituents are present in the rock, so that the percentage of manganese is relat vely low, the manganese naturally forms silicates that contain a smaller percentage of manganese, such as the other manganiferous pyroxenes or manganese-garnets. The abundance of rhodonite in the manganiferous rocks of metamorphic origin is then explained by the frequency with which the original sediments from which the rocks of the gondite series were formed contained a high percentage of manganese. The same reasoning as for Vizagapatam explains why rhodonite is not formed in the rocks intrusive into the gondite series. As already mentioned, rhodonite exhibiting measurable crystal faces has never been found in the Indian deposits, although such crystals are sometimes found in other parts of the world. This is probably due to its usual metamorphic origin, the rocks in which it occurs having been subjected to great pressures at the time of formation, so that as a rule they contain no open spaces or cavities. Such spaces as there are, have been formed by the action of waters subsequent to the formation of the rhodonite, so that if any such empty spaces are lined with crystals, they are of subsequently formed minerals, such as the various oxide minerals, rather than of rhodonite. This can- not, however, be the whole of the explanation why rhodonite crystals are not found, because the manganese-garnet, spessartite, associated with the rhodonite and formed under the same circumstances, frequently occurs in well-formed crystals, usually in a matrix of quartz, but sometimes in a matrix of rhodonite. Hence it seems as if rhodonite has very little tendency to take on well-crystallized forms. In the rocks of the gondite series it sometimes occurs as rhodonite-rock, forming Cuap. V. ] RHODONITE. 3 143 practically the whole of the rock. Then there are varieties of rhodonite- rock containing small quantities of spessartite or quartz. or of both; and from these there is every gradation through rocks composed of roughly equal quantities of rhodonite and spessartite, or more rarely of rhodonite and quartz, up to rocks composed practically entirely of spessartite or quartz. Whenever the rhodonite occurs in rocks with spessartite it seems to give the garnet a good opportunity to assume a crystalline form. On rare occasions, however, I have seen under the microscope rounded idiomorphic crystals of rhodonite enclosed in spessartite, as for example inarock from Jothvad. As will be seen from the list of rocks of the gondite series given on page 329, this mineral may also be associated with rhodochrosite, amphibole, orthoclase, magnetite, manganese-mica, and barytes. In the rocks of the gondite series the thodonite individuals are sometimes as large as 1 or even 2 inches across, then exhibiting well their perfect cleavage, and often enclosing other minerals, especially spessartite, poikilitically. In the manganese-pyroxenites of the Vizagapatam district the rhodonite usually occurs in prismatic individuals together with the other pyroxenes in the rock. Owing to the rather loose state of aggregation, in some cases, of the granules of these pyroxenites, these prismatic individuals are often easily detached and are sometimes as much as ~ an inch in length. The appearance of a piece of rhodonite-rock under the microscope is shown in figure 3 of Plate 12, which illustrates why the rock often resembles a crystalline limestone in structure as seen in the hand-specimen. For the rock to be so fresh as in this example is, however, not the rule; for this mineral is very prone to alteration. This alteration seems to start along the cleavage cracks of the mineral as shown in figure 4 of Plate 12, and then to spread in all directions so as to leave smaller and smaller clear areas between the altered portions, the final result being a blackened mass of manganese and iron oxides. When the alteration is taking place, the product seen along the cracks is not all black in colour. but areas and strings of a curious orange to yellow-brown substance, polarizing as an aggregate in the way serpentine sometimes does, are also formed. The nature of this substance is not known, but it may be an intermediate product between rhodonite and manganese oxide. In some cases, moreover, the alteration of the rhodonite does not seem to take place along the cleavages in particular, but to spread out irregularly over the mineral in moss-like or dendritic forms, and es irregular cloudings, Alteration. 144 MANGANESE DEPOSITS OF INDIA : M'NERALOGY. [ Part I: these all being dark brown in colour. The opaque portion, moreover, seems tobe black and brown in patches, the brown perhaps indicating that the fresh rhodonite contains a considerable proportion of iron oxides. In some cases the final result seems to be psilomelane, in others braunite, the intermediate product being an indefinite dark brownish black ore that can be scratched with comparative ease. It seems probable that the latter variety would not pass into compact braunite without the in- troduction of manganese in solution from other portions of the mass of rock in which the altering mineral occurs. The consequence of the ease with which this mineral undergoes oxy-alteration is that all outcrops of rhodonite-bearing rocks are black (or dark brown) ; but when the rock is broken open it is frequently found that this blackening does not extend for more than | to 2 inches in depth, the bright pink mineral lying beneath: Nearly all the loose blocks first found by Mr. Middlemiss near Chintelavalsa and Taduru in the Vizagapatam district, are completely blackened outside and are quite fresh inside, the blackened coat being often as much as 2 inches thick. This proves that the blackening of the mineral is going on at the present day ; for these blocks must have been blackened, at least on most sides, since they were detached from their original position im situ, which lies on the hill-side above, and from which such blocks are presumably still being detached under the influence of the ordinary meteoric agencies. In my paper ‘Manganese in India’ !, I have already drawn attention to the fact that rhodonite-rock in other re apie om parts of the world is frequently turned to account as an ornamental stone on account of its great beauty when polished, the most famous locality for this industry being the Ural Mountains. In some of the deposits of the Central Provinces there are considerable amounts of beautiful examples of both rhodonite-rock, and of rose-pink rhodonite-rock studded with orange-coloured spessartite crystals. As localities for the former Maneg4on and Risara in the Nagpur district may be mentioned, whilst fine examples of the second variety are to be found at Chargaon in the same district. I have, since that paper was written, been able to re-visit and examine the Manegdon deposit. It had been much more opened up than at the time of my first visit ; and I must confess my disappointment at the small quantity of good rhodonite-rock suitable for use as an ornamental stone that seems to be available, this being due, not to any deficit in the quan- 1 Trans. Min. Geol, Inst. Ind., Typ: 120, (1906). Cuap. V.] MANGANESE-AMPHIBOLES. ; 145 tity of rhodonite, but to the large proportion of it that is too much blackened to be of use ; for it must be mentioned that a small proportion of oxy-alteration, as long as it does not give rise to decayed spots, improves, if anything, the beauty of the rock, on account of the mottlings, spots, and moss-like markings it produces. A considerable proportion of small pieces of rock suitable for the manufacture of small ornaments could be obtained, but it would be very difficult to obtain larger pieces suitable for such purposes as the manufacture of table tops. Manganese-amphiboles. Although, in the Archean manganese-silicate-rocks of India, the commonest of the dark silicates are garnets, with pyroxenes next, yet amphiboles have been found at several localities, in no case, however, except at Kajlidoneri, in any but very.small quantities, forming no appreciable proportion of the whole mass of rock in which they occur. These amphiboles can be divided into two main divisions according to their colour. One division is blue, lilac, or lavender, in colour and will be considered under the heading of winchite, a name given to the variety found at Kajlidongri. These have been definitely determined to be manganiferous. The amphiboles of the other group vary from yellow to greyish-green, greyish, and chocolate, although the latter colour is probably the result of alteration. These varieties have not yet been carefully investigated, but on account of their association are probably manganiferous and will be considered under the heading of dannemorite, the described amphibole to which they bear the closest resemblance. As regards occurrence, it is to be noticed that no amphiboles have yet been observed in the igneous manganiferous rocks of the kodurite series of the Vizagapatam and Ganjdm districts, and that all the known occurrences of amphiboles in Indian manganiferous rocks are in the varieties that I look upon as metamorphic in origin, belonging always to the gondite series. They have been found in all of the three areas in which rocks of this series have been recognized, namely, Narukot, Jhabua, and the Central Provinces. Before considering the various occurrences of these amphiboles in India it will be well first to give a short account of what is known about the manganiferous amphi- boles of other parts of the world. There are two main divisions of the manganiferous amphiboles, corresponding to the two following minerals :— Foreign mangani- ferous amphiboles. Dannemorite . . (Fe,Mn,Mg) SiOs, Richterite - : - [(K,Na)2, Mg,Ca,Mn] SiOz, 146 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: which are to be regarded as two distinct varieties of the non-aluminous section of the amphiboles. There are also some amphiboles of more aluminous nature that contain small proportions of manganese, namely arfvedsonite, barkevikite, and philipstadite ; but since, judging from the published accounts, none of the Indian specimens are likely to come under any of these species they will not be further considered here. The data given below concerning these two minerals are taken from Dana’s ‘System of Mineralogy’ and its appendix, and the references to the original papers describing these minerals will be found in that work. Dannemorite.—Under this name are included the minerals to which the names of asbeferrite, silfbergite, and hillangsite have been given. All the occurrences of this mineral are at Swedish localities. In colour the mineral varies from ash-grey through greyish white, greenish grey, and brownish grey, to yellowish brown and dark yellow, the different colours correspond- ing, no doubt, to the differences in composition of the different specimens analysed. The mineral is in one case described as being fibrous or columnar like asbestos. The variety silfbergite is distinctly pleochroic, and has an extinction angle on 6 of 13° 45’, and has G = 3446 and H=5'5, The four analyses quoted by Dana show the following range in the amounts of the various constituents :— Side. 46°25—48'89 Al2O3 . 0 9146 FeO 28°17—40°40 MnO 8°34 12°08 MgO 2°92— 8:39 CaO 0°73— 3:22 from which it will be seen that the chief constituents are silica, and ferrous and manganous oxides, alkalies being absent. Richterite—Under this name are included the varieties known as marmairolite and astochite. The colour varies considerably in the different kinds, richterite being brown, yellow, or rose-red, marmairolite yellow, and astochite blue to greyish violet. The extinction angle ¢,¢ is given as 17° to 20° for richterite, whilst the extinction angle of astochite is given as 15° 40’ for the blue crystals and 17° 15’ for the greyish-violet ones. The specific gravity of these minerals varies from 3°05 - 3°10. Six analyses quoted by Dana show the following limits of composition :— Si02 . ‘ : : : . §2°23—56'27 AleO3 . 2 ; 3 P 2 0 —23°31 FeO... : : : : : 0'15— 2°80 Fe203 , : ; : OF = 177 MnO. ; ; : ; 4°86—12°71 MgO. a) av ie ee Ome eee CaO f ; < ; ‘ 5'20— 8°43 K,0 . Fi ; 4 : , 0°66-—— 6°37 Na,O . ‘ : - : ° 2°77—- 6°33 Cuap, V. ] MANGANESE-AMPHIBOLES. 147 From this it will be seen that the chief constituents are silica, man- ganous oxide, magnesia, lime, and alkalies, the only constituents that are prominent in both dannemorite aid richterite being the silica and manganous oxide. Richterite and its varieties all come from Langban and Pajsberg in Sweden. We can now pass to the consideration of the Indian amphiboles found in the manganese-ore deposits and associated rocks, treating the yellow and greyish ones under the heading of dannemorite and the lilac and blue ones under the heading of winchite, which, as will be shown below, is allied to richterite. Yellow and Greenish-grey Amphiboles (Dannemorite 2). The amphiboles of this group can for convenience be divided into two sections, those from the Central Provinces, and those from Kajlidongri, Central India. In the Central Provinces the following occurrences may be noted :— _ Balaghat district :— 1. Chikmara . : . In gondite. Bhandara district :— 2. Hatora, 4 é . In gondite. Chhindwara district :— 3. Bichua 4 4 . In gondite. 4. Bichua : : - In rhodonite-gondite. 5. Wagora - : . In spessartite-rhodonite-rock- Nagpur district :— 6. Kandri : - . In gondite. 7. Nandapuri . ; . In gondite. §. Sttakl : . In gondite. 9. Sitagondi . : . In spessarti‘e-rhodonite-rock. 10. Parsioni . ; . In orthoclase-rhodonite-gondite with rhodochrosite. 11. Pali : - . In piedmontite-gneiss (granulite). It will be seen from the above that the rock in which this amphibole usually occurs is gondite or spessartite-quartz-rock. but it also not unfrequently occurs in varieties con- taining rhodonite. The gondite may be either the fine or coarse-grained variety ; but is more usually the coarse-grained type, perhaps because the amphibole is more conspicuous in the coarser varieties and so more likely to be noticed and collected. In the coarse varieties the spessartite I rE & Central Provinces. 148. MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: is often } to $ inch in diameter. In one specimen from Hatora, however, the amphibole occurs as rather conspicuous radiate white asbestiform needles often altering to a greenish black colour, on the parting planes of a fine-grained variety of gondite. In the Kandri example the rock is also fine-grained, the amphibole, the determination of which is somewhat doubtful, being noticed only under the microscope. Usually the mineral is conspicuous in the hand-specimens, appearing as radiate or semi-radiate bundles or sheaths, usually with the fibres } to } or even 1 inch in length. When fresh the colour of these sheaths varies from greenish grey to brownish green and yellowish or buff. The fresh mineral is best seen in the specimens from Parsioni and Chikmara (col- lected by Mr. C. M. P. Wright). When in this fibrous condition the lustre of the mineral is silky. But sometimes the width of the individual fibres of the aggregate is greater and then the mineral tends to be bladed in appear- ance. Very frequently the mineral is partly altered, the colour then being usually some shade of chocolate, whilst the mineral is softer than when fresh. Under the microscope this alteration is seen to take the form of a brownish powder deposited along both the cleavages and cross cracks of the mineral. Owing to the fibrous or thinly prismatic nature of the mineral it is very difficult to obtain good sections for microscopic examination, the fibres separating out long before the section is sufficiently thin, Nevertheless, several prismatic sections have been obtained ; but it is almost impossible to obtain a cross section showing the cleavages characteristic of amphibole. In one specimen from Bichua, however, such a section was obtained exhibiting the cross-cleavages of the amphibole group and thus confirming the deduction as to the nature of this mineral. The prismatic sections show extinctions (¢ » ¢) up to 22°, the highest value in several examples approximating to this figure. The birefringence is low, the polarization colours being of the first to second order. In some cases the mineral is practically colourless as seen under the microscope ; but in others it shows pale colours, then being slightly pleochroic. Thus a slide of the Hatora occurrence shows :— =very pale brownish yellow, b=slightly darker brownish yellow ; whilst one from Bichua shows a pleochroism of pale greenish brown to colourless. From their mode of occurrence and general appearance it seems probable that all the above occurrences are of the same mineral, except that of Pali, which is in a piedmontite-gneiss, This amphibole is yellow- Cuap. V.? WINCHITE. 149 ish white in hand-specimens and colourless under the microscope. Con- sidering the fact that all the constituents of the rock in which it occurs are non-manganiferous except the piedmontite, it is not at all improbable that this amphibole is also nor-manganiferous. At Kajlidongri I found two occurrences of amphiboles, leaving the winchite entirely out of consideration. One of these is in a banded rock composed of yellow pyroxene, yellow amphibole, and quartz, with a little felspar. The pyroxene is that noticed on page 136. The amphibole is in irreguiar prismatic individuals as seen in the microscope section, and shows the following pleochroism :— Kajlidongri. a=yellow with a brownish or orange tinge, b=pale straw, sometimes with a greenish tinge. The crystals are of low birefringence, showing under polarized light a very patchy appearance. This is due to zoning, the outer portions of the crystals having a larger value for the angle a*c¢ than the inner, with a more or less gradual change from one to the other. One example showed patches with an extinction angle of 224°, in a main portion with extinction angles of 45° to 54°; whilst another showed a change from 10° inside to 37° outside. In this character the mineral very closely simulates winchite. The other occurrence is in a rock composed of crimson mica, talc, apatite, andthe amphibole. The latter was not evident in the hand-specimen, and under the microscope practi- cally colourless, so that it might be either tremolite or a very pale vanety of winchite. From a consideration of the foregoing it seems that in general aspect the amphibole of the Central Provinces bears considerable resemblance to dannemorite. Winchite. Of this mineral, originally found by Mr. H. J. Winch of Meghnagar at the manganese mine, Kajlidongri, Jhabua State, Central India, I gave a preliminary description in the Rec. Geov. Surv. Ind., XXXI, pp. 235, 236, (1904); and in the Trans. Min. Geol. Inst. Ind., 1, p. 79, (1906), announced the name of it as winchite, after the original discoverer. In February 1905 I was able to visit Kajlidongri and collect considerable quantities of the mineral, with the rocks in which it occurs. As the result of a study of a large number of thin sections under the microscope I am 150) > MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: able to add considerably to the original description, and propose to give here a general account of the mineral. As will be seen by consulting the sketch-plan of the Kajlidongri deposit given on Plate 19, the chief spot for this mineral is at the north end of the deposit, where the rocks containing it form a band about 4 feet thick, with a strike and dip conformable to that of the ore-deposit.! The associated rocks had not been clearly exposed at the time of my visit, but it looked as if the winchite-bearing rocks formed one wall of the deposit at this point: they were probably formed by the metamorphism of calcareous manganiferous sediments, accompanying the ordinary manganiferous sediments trom which the ore-body proper was formed by metamorphism and subsequent chemical alteration. The band in which the winchite occurs is made up of layers, ranging up to 4 inches in thickness, of various composition, nearly all of them containing winchite. Tite most characteristic rock is one composed of winchite, calcite, quartz, and the magnesian variety of braunite of which an analysis is given on page 68. Another common occurrence is in a rock that may be described as a very fine-grained white or pale grey quartzite containing abundance of lavender-coloured winchite with greenish spots and crystals of blanfordite. This rock is usually banded and is often friable so as to simulate a sandstone. Besides these two varieties there are several others of less importance, which contain some or all of the fore- going minerals, with some or all of the following minerals in addition— plagioclase, apatite, crimson mica, and talc. In the rock first mentioned, which from its structure may be called a winchite-schist, the winchite is usually in more or less flattened crystals tending to be of a bladed shape. They are of a hight blue colour, with perhaps a tinge of lavender. Owing to the predominance of this mineral the whole rock is of a striking light blue colour. In the quartzites mentioned above the mineral occurs either as radiate tufts of lavender colour on the parting planes of the rock, or as small isolated prisms, often beautifully formed, which may be either of a rich deep cobalt blue with a tinge of lavender, or, when smaller, of a rather dark lavender colour. Sometimes, as noticed on page 128, the radiate tufts nave blanfordite of green colour in the centre with peripheral winchite. In the schist the winchite individuals usually range from 0°5 to 2°0 cm. in length. In the quartzite they range from | or 2 mm. up to perhaps as much as | cm. This mineral also occurs, though but sparingly, in the vitreous quartzites adjacent to Occurrence. 1 An unimportant occurrence in another part of the deposit is noticed on page 686. Cuap. V. | WINCHITE. 151 the main winchite-bearing band. In this rock the mineral is found in small tufts tending to be radiate in structure. From the fine-grained quartzite mentioned above I have beea able to obtain several small crystals sufficiently well seeeneabcerapliic formed to permit of the measurement of the angle caaracters. E - mm”’. In general these crystals are simple prisms, showing no other faces, and with irregular terminations. But in one case an embedded crystal was found showing, in addition to the prism, the clino-pinacoid 6, a small steep clino-dome, and the basal plane, c, sloping shghtly forwards. The portion of the crystal visible is only 15 mm. long, and about 1 mm. from acute angle to acute angle of the prism. For the determination of the angle mm’’’, I was able to separate three suitable crystals. These can be designated I, II, III. I. This is 4 mm. long and 1-5 mm. wide and is dark blue in colour. It is a simple prism slightly tapering. All the faces are rather dull owing to the projection of included specks of braunite. One face is cracked at one end and another has a little white crust on a portion of it. Using only the acute- angled edges of the crystal several measurements made over each of these edges gave a mean value of 55° 17’ for the 44? prism angle mm’”’. II. This is the best crystal and is an unusually transparent one of lavender-blue colour. Itis 2°5 mm. long and 0:08 mm. broad. It is a simple prism, with the faces finely striated in a vertical direction, and with a few included specks of braunite. The reflections from all the faces except one were good. Measurements taken all the way round, using all the faces gave 55° 273’ as the mean of several determinations. Lying on one of its faces on a glass slide on the stage of the microscope the mineral shows well the characteristic pleochroism of winchite, namely from rich lilac, or even violet, to sky-blue. The axis corresponding to the lilac colour is the one nearest to the vertical crystallographic axis, so that the crystal is one of what has been designated the basic variety. The crystal is irregularly terminated at both ends. Ill. This is a portion of a large crystal, and is 0-6 cm. long and 45mm. broad. It is opaque darkish cchalt-blue in colour 152 - MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: and has its surface lustre-mottled to a certain extent owing to numerous small inclusions of the usual manganese-ore (braunite). The reflections from three of them, however, are sufficiently good for measurement. The mean of the values obtained by making use of the two edges thus available was 55° 30’, and then 55° 284’ for a re-determination, giving a raean of 55° 291’, Thus we see that the mean value for crystal II is 55° 27}’ and for II is 55° 291’. Hence 55° 281’, or for simplicity 55° 28’, can be taken as the value of the angle mm”’ for winchite. Considering the fact to be noticed below, that there is a great variation in the extinction angles measured in different individuals and even in different parts of the same individual, and that this variation is probably an expression of the variable composition of the mineral, we should expect a certain variation in the interfacial angles of different specimens. Hence the value for the angle mm”’ as measured on crystal I, 55° 17’, may be that correspond- ing to a specimen of slightly different composition. Hence the value of the angle mm”’ may be taken varying from 55° 17’ to 55° 28’. For the sake of comparison the values of this angle mm”’ for the various amphiboles to which winchite may be related are given below. They are taken from Dana’s Mineralogy :— Amphibole 55° 49’ Richterite . Be Bata 7 Astochite : - 56° 27’ (cleavage angle). Under the microscope the mineral is found to exhibit the following Pleochroism. pleochroism :— a = pinkish lilac. = paler lilac. c = blue. in one case, in a thick slide, the following was the pleochroism observed :— a = amethystine-rose, b = pale, t= bright sky-blue, the b axis colour being the palest of the three. Cuap. V] WINCHITE. 153 With regard to the variable extinction angles and marked zoning exhibited by winchite I will quote what I have Extinction angles. ae Boe 6 said in the original account! :— ‘ By polarized light it is seen that the mineral shows irregular zoning, due pro- bably to varying composition. As the inner zone seems to have the presumed manganese-ore dust developed in it more readily than the outer shell, it seems probable that there is a gradual change from the most basic composition inside to the most acid outside. This change in composition is accompanied by a change in position of the elasticity axes. For the basic portions of the amphibole the a elasticity axis is the one nearest to the vertical crystallographic axis ¢. The angle may be as low as 16°, but as one passes from the interior, most basic, portion to the outer, most acid, portion in a zoned individual, the axis a gradually swings away from the vertical crystallographic axis ¢ till it makes an angle sometimes as large as 70° with ¢. The elasticity axis ¢ has of course now rotated into proximity with the crystallographic axis ¢, making with it an angle of 20°, so that cn é = 20°. ‘ As will be seen from the pleochroism scheme, this rotation of the elasticity axes is accompanied by a change from lilac to blue, as the elasticity axis nearest the vertical crystallographic axis changes from a to ¢; consequently these compound crystals do not show even colouring, but are in irregular patches of blue and lilac. Though some of the crystals in the microscope slide are almost entirely of one composition, either basic or acid, it is easy to distin- guish them at once by the colour corresponding to the elasticity axis nearest ¢ thus’ :— Chemical character. | Axis nearest ¢ is | Corresponding colour. Basic w Pinkish lilac. Acid c Blue. The assumption made above as to the chemical character of the different zones is of course difficult to prove or disprove. I have not been able to separate for analysis portions of the acid and basic varieties, and I doubt if this is possible. As the analysis to be given below shows such a small proportion of manganese in the mineral, it seems difficult to believe that the small differences in the amounts of this element possible in the different zones of the mineral could produce such striking varia- tions in the extinction angles ; and that, even if this be so, the small proportion of manganese present could, by separating out in the oxide form, give rise to such considerable clouds as are referred to above. For convenience sake, however, I shall continue to refer to these two portions l Rec. Geol. Surv. Ind., XX XI, p. 235, (1904). 154 . MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: of the mineral as acid and basic. There is little to add to the above account of the extinction angles of this mineral. In those examples in which zoning is absent the whole mineral seems to be as a rule com- posed of the basic variety, and the most usual value of the angle a4 ¢ in these unzoned crystals is 20° to 26°, usually nearer the latter figure. In one case where I found an entirely acid example without zoning the extinction angle 4 / ¢ was 38°. In the first account of this mineral I said that the polarization colours rarely rise above the first order. But now, after examining a large number of sections, I find that this is not exactly true. Sometimes the colours are as high as green and yellow of the second order. In the zoned crystals the interior more basic portion exhibits somewhat higher colours under polarized light than the outer more acid portions. It is possible that this difference is due to the section of a crystal being slightly thinner at the edges, so that a small thinness of the adjoining mineral passes under it at this point. From a careful examination of the sec- tions, however, I do not think this is the case, but that the difference in birefringence is a true one. I have not been able to measure the bire- fringence, except in the chance sections one gets under the microscope. But from these, by comparing the colours exhibited with those of the quartz usually present in the same slide, I have deduced the values of the birefringence given below. In one section of a zoned individual, y - « worked out as 0°030 for the most basic portion, and 0-024 for the most acid. In another shde, the value of y-z worked out as 0°020 to 0-022, as deduced from several sections irrespective of their basicity. In one section giving straight extinction and showing the «and b axis colours, and consequently to be regarded as the basic variety, the polarization colour, being the same as that of quartz, indicated the value of 0-007 to 0-008 for 3 - a It must be noticed that sections of winchite often ex- hibit the polarization colour usually referred to as ultra blue, together with various other allied colours of curious tint not belonging to Newton’s scale. These are particularly prominent in well-zoned individuals, so that it seems probable that it is due to the outer acid zone of a crystal compensating the double refraction of the inner basic zone. From the above it will be seen that the general values for the birefringence of this mineral may be given as follows :— Double refraction. y-4 = 0020 to 0°030, f-a = 0°007 to 0008. Cuap. V. ] WINCHITE. 155 To obtain material for the chemical examination of this mineral was : a matter of considerable difficulty. The rock Separation of the : Ze ; : mineral. chosen for this purpose was the winchite-schist composed of winchite, calcite, quartz, and braunite. This was broken up to pass a 100-sieve and aiter removing the greater portion of the quartz and calcite by means of Sonstadt’s solution, of such a strength that most of the amphibole and braunite sank and most of the quartz and calcite floated, the impure mixture of braunite and am- phibole was treated with concentrated Sonstadt’s solution (G=3-25) and separated into two portions, one being chiefly amphibole and the other a mixture of amphibole and braunite. The amphibole in the latter fraction contained an abundance of included black granules tending to show square outlines and doubtless to a large extent braunite, though some of it may have been some indefinite oxide of manganese produced by alteration of the mineral. It was doubtless to these inclusions that this amphibole owed its higher specific gravity, rather than te an appre- ciably different composition ; for although. as seen under the micros- cope. the majority of the crystals seemed to be of the type I have deserib- ed as_ basic, yet there were also some of the acid ones and some of the composite zoned individuals. The amphibole that floated in Sonstadt’s solution contaied abundance of included and attached calcite and much less of the included manganese-ore. The amphibole itself seemed to consist of the basic and acid varieties, with some of the com- posite zoned individuals. Tlis portion of the amphibole was then treated with Sonstadt’s solution of specific gravity 2°959 in which it neatly all sank. The material that sank was then left overnight in hydrochloric acid diluted to over 1 in 50, to remove the adherent calcite. From an examination of the amphibole under the microscope I do not think that this acid attacked the amphibole to any appreciable extent. The amphibole was then treated with a solution of specific gravity 3-024, in which most of the mineral floated, whilst a portion remained suspended, and some sank. The portion that floated was examined under the microscope and found to be very nearly free from included manganese- are. It was subjected to one or two more separating operations and then used for analysis, the amount so available being 0°383 grammes only. The separated material was carefully examined under the microscope and it was found that the majority of pieces, which were in the form of small prismatic chips, were transparent and quite free from inclusions. The few inclusions present were evidently braunite; but they were so small in comparison with the volume of the amphibole that I de not 156 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: think they can have, appreciably, affected the composition, not even to the extent of the small amount of manganese that the analysis shows to be present. From the above it will be seen that the specific gravity of the pure mineral analysed lies between 2°959 and 3-024; it can therefore be taken as 3°0.. Doubtless there are some few grains that lie outside the above limits, but the majority of such owe their greater specific gravity to the inclusions of manganese-ore. Perhaps, allowing for variations in composition, we can give the specific gravity of the mineral when free from inclusions as ranging from 2°95 to 3°05. The colour of the pure specimen of the mineral thus obtained was a bright azure blue as viewed in bulk in a glass tube, whilst under the microscope each tiny prism showed its distinctive pleochroism. The material thus obtained was analysed by Mr. T. R. Blyth, of the Geological Survey of India, with the following Specific gravity. Chemical composition, result :— Si02 55°64 Alz03 1-08 FeO 6°35 MnO 0°77 MgO 22°09 CaO 7°64 NagO 2 . - : 5 ony e289 K20 ‘ - é C : c 0°98 Loss on ignition 2°95 Moisture at 100° C. 0°14 | —_— S i | Or ow He recorded the absence of titanium, chromium, zinc, barium, phos- phorus, and flourine. The amount of material available was not suffi- cient for the determination of the state of oxidation of the iron and man- ganese. In the first place I assumed the above to be the correct state of oxidation and converted all the protoxides into metasilicates of the gene- ral formula RSiO3, taking for the purpose the requisite amount of SiO». In the same way the Al»O, was converted into a silicate of the formula Al,03.39i09. After doing this 2°65 per cent. of silica was left over. If the loss on ignition be assumed to be due to combined water, 9:89 per cent. SiO would be required for the formation of H,Si03. I then supposed the iron to be present as FegO3 and converted this into Cuap. V.] WINCHITE. 157 Fe,03.38i09, as before leaving the loss on ignition out of account. There was then found to be an excess of only 0:03 per cent. of Si09. On this interpretation an allowance has to be made in the analyses for a con- version of the Fe 903 into Fe30, on ignition, The analysis can then be restated as follows, on the assumption that the iron is in the form of Fe,03 :— Si0s 55°64 AlgO3 1°08 Fe203 7°06 MnO 0°77 MgO 22°09 CaO 6 7°64 NagO 2°89 KsO 0°98 Loss on ignition . : ; a A ATeI Moisture at 100°C. , : : : 5 Mele 101-00 - This can be arranged as follows :— MgSi0g : 5 ; ‘ : 2 65548 CaSiOg “ 5 : , : . 15°87 NagSiO3 3 . ; 4 5°70 KoSi03 F : é 5 5 ale ai MnSi03 : : ; . : r 1°42 Feo03°38Si02. : : : . » Lo 03 AlgO3°3Si02g . : 4 : : 3°06 Loss on ignition : . 5 : ell Moisture . . : : £ : pee One: 100°97 Excess Si02g.. 3 : 4 : eee ORS 101-00 The formula corresponding to this is :— 14 [(Mz,Ca,Naz,K2,Mn,)Si09] + [(Fe, Al)203.38i09] ; or, with all the oxides shown separately, it is :— (MgO)53 (CaO)13 (Na2O)4 (K20), (MnO); (Alg03)1 (Fe203)4 (Si02)ag. 158 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: If the analysis of this mineral be compared with those given for richterite and its relatives on page 146, and with that of the theoretically pure tremolite, which is as follows :— SiOz . f 5 : é ; a aNeeA MgO . 2 : : : E . 28:9 C2Oke : F : ‘ , . 34 100-0 it will be seen that winchite has affinities with both tremolite and richterite. Neglecting the state of oxidation of the iron, winchite is to be regarded as a tremolite containing, in addition to magnesia and lime, as its base constituents, oxide of iron in considerable quantity with a small amount of alkalies and manganese oxide. Or it may be regarded as a variety of richterite with the manganese to a large extent replaced by iron, and with a smaller amount of alkalies than richterite usually contains. The latter is the closer relationship and consequently this amphibole is to be regarded as a variety of richterite. The variety of richterite to which it shows the closest relationship is astochite, the similarity of these two minerals as regards their colours being very close. The reason for giving the Indian mineral a distinct name is found in its interesting optical behaviour, which is no doubt due to its somewhat different composition. As both astochite and winchite show blue and violet or lavender colours, it is interesting to note that in astochite the MnO ranges from 6°49 to 12°71°/, and the FeO is only 0°15 to 0°21%; whilst in winchite the relative abundance of these two consti- tuents is just the reverse, the FeO being 7:06 per cent. and the MnO only 077%. From this it is not evident which element is the cause of the colouration of the mineral, if it be either of them and not the alkalies. ! As regards the angle mm”’, however, winchite is more closely related to tremolite than to a:tochite (see page 152). Sometimes varieties of winchite are found at Kajlidongri that are white in colour and are then indistinguishable in appearance from tremolite. 1 It is interesting to note, however, that an azure-blue pyroxone from Middle Gila, New Mexico, noted by G. P. Merrill and R. L. Packard in the Amer. Jour. Set. XLII, pp. 279, 280, (1892), was found to be avariety of di pside containing !*1! per cent. of FeO, and no other constituents except Si0g, MgO, and CaO. The authors ascribe the colouration of the mineral to this FeO. Under the microscope, however, the mineral is colourless. Cuap. V. ] JUDDITE. 159 Juddite. Associated with the blanfordite of Kacharwahi in the Nagpur dis- trict there is a manganiferous amphibole with a pleochroism analogous to that of the blanfordite with which it is associated ; but it is, if possible, still more beautiful. The tints seen in a microscope slide showing a considerable number of sections of this mineral consist of various shades of rose, carmine, lilac, purple, blue, green, orange, and orange- pink. These tints are often very delicate, and their great variety is doubtless due to the combination of the colours corresponding to the different axes in varying proportions in various sections. As crystals of the mineral have not yet been isolated, it is very difficult to say which particular sections show the unadulterated axis-colours. But I think the following is somewhere near the true pleochroism scheme :— a=carmine, b=blue with a lilac tinge, to pale green with a lilac tinge, ¢=orange or pinkish orange. It will be seen that the colours corresponding to the * and baxes are somewhat similar to those of winchite ; but the ¢ axis colour is quite different. The extinction angle # 4 ¢ seems to have a maximum of about 30° in sections showing the & and b axis colours. Some of the sections showing carmine and shades of green are at right angles to an optic axis, and from the brushes obtxined in these sections it seems that the mineral is positive, so that ¢ is the acute bisectrix. I did findmg not succeed in a section accurately at right angles to this bisectrix, but one figure that approached this position seemed to show crossed dispersion, as one would expect if § =¢, One section showing orange and green tints, and hence at right angles to the 4 axis, was apparently at right angles tc the obtuse bisectrix, this also pomting to the positive character of the mineral. In a basal section showing the characteristic cross-cleavages of amphi. pole, the colour corresponding to the long axis of the cleavage rhombs is pinkish orange to reddish orange (c), and that to the short axis is rich violet, the latter colour being compounded of the a and ¢ axis col: urs. It seems probable that the mineral is monoclinic and that the ¢ axis coincides exactly with the § crystallographic axis, and that the a and b axes lie in the plane of symmetry. But certain anomalies in the behaviour of the mineral suggest the possibility that the mineral may be triclinic approximating closely to monoclinic in the axial angles, This point cannot be settled at present. 160 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [Part I: Hence we can say provisionally that this mineral is positive, has its plane of optic axial plane at right angles to the plane of symmetry of the mineral, and shows a pleochroism not shown by any other amphibole yet described. The position of the optic axial plane is interesting because with rare exceptions the optic axial plane and plane of symmetry in the members of the amphibole group are coincident. The only two exceptions to this rule mentioned by Iddings in his ‘ Rock Minerals’ (page 345) are crossite from California and a blue amphibole from Viezzena Thal. It is not yet possible to give any details as to the macroscopic or chemical characters of the mineral, because it has not yet been distinguished in hand-specimens from the blanfordite with which it is associated. But the optical characters of the mineral leave no doubt that it is a new variety cf the amphibole group; I propose to name it juddete in honour of Professor J. W. Judd, F.R.S., and as a respectful tribute from a former student. It gives me special pleasure to be able to associate the names of Professor Judd and the late Dr. W. T. Blanford with two such beautiful minerals es the amphibole and pyroxene found in this Kacharwahi rock, CHAPTER VI. MINERALOGY —continued. Silicates (contd.)—Garnets. Manganese-garnets—S pessartite—S pandite—Grandite—A plome—C, lderite Manganese-garnets. The garnets form a well-marked group of minerals belonging to the holohedral section of the isometric system, the commonest forms being the dodecahedron, trapezo- hedron (or icosatetrahedron), and hexoctahedron. Cleavage or parting parallel to the dodecahedron, d, is sometimes shown, but the mineral usually breaks with a sub-conchoidal to uneven fracture, H.—6°5 - 7:5. G.=3'15 - 43. Lustre vitreous to resinous. Colour various shades of red, brown, yellow, green, and black. Streak white. Often show anomalous double refraction. The foregoing characters are taken from Dana’s Mineralogy. Characters of garnets. In composition the garnets are orthosilicates conforming to the gene~ ral formula 3R”O0.R’503.38i09._ They are usually divided into six species according to the bases replacing the R” and R’”. The R” may be replaced by Ca, Mg, Fe, and Mn, as main constituents; whilst occasionally alkalies, nickel oxide, and baryta, in small amounts, may enter into the composition of this group. The R:O0s3 group may consist of AlgO3, Feo03, or Crg03; whilst in very rare cases Y903 may enter into this group in small amount. Dana does not give any analyses in which Mn enters into the R203 group; but as will be seen from the analysis of a example of spessartite from Chargdon in the Central Provinces, it is necessary to assume that in this case at least some of the manganese is inthe form Mn,O3. The silica is sometimes, though rarely, replaced by TiOg, and in one case by ZrOy, to a very small extent. Composition of garnets. The names and formule of the six recognised species of garnets! are as follows :— Grossularite . é J - 3CaO.Ale03.38i02 Pyrope . : : : - 3MgO.Al203.388i02 Almandite . : A . 8FeO.Al203.38i02 Spessartite . 5 3 - 38Mn0.Al203.3Si02 Andradite . - : . 38CaO.Fe203.38i02 Uvarovite . , ; - 3Ca0.Cr203.3Si02 1 Omitting Bohoxlomite: 3Ca0.(Fe, Ti)203.3(Si, Ti)Oe. 162 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Parr I: The garnets found in Nature seldom conform exactly to the foregoing formule, but are usually found on analysis to be Isomorphousreplace- . ; - Zi3 ment! intermediate in composition between two of the ideal species. This is usually ascribed to the isomorphous replacement of the various metals in the protoxide and sesquioxide groups one by the other. Whilst it is convenient to use this term ‘isomorphous replacement’, it is as well to remember that in all probability this replacement cannot take place within the molecule ; but that the phrase really means that there is a molecular mixture of molecules of the same structural formule and the same or nearly the same crystalline form. Hence these garnets are best regarded as made up of mixtures of the molecules of two or more of the type garnets in varying proportions. The garnet receives its name according to the predominant molecule. All the six species of garnets may contain a certain pro- portion of manganese in the RO group!. But in connection with the Indian manganese-garnets it will only be necessary to consider three species, namely, spessartite, andradite, and grossularite. The published analyses of spessartite often diverge widely from the formula given above. The commonest divergence is for the MnO to be to a considerable extent replaced by FeO, the mineral then gradating towards almandite ; and it is obvious that a point may be reached at which it is impossible to decide whether to call the garnet spessartite or almandite. In the same way the Al,O3 may be replaced to a considerable extent by Fe.03. No garnet seems to be known conforming to the formula 3MnO.Fe903.38i09,2 so that such a garnet as the above would still be called spessartite. If, however, the replace- ment of Al,03 by Fe903 be accompanied by the replacement of MnO by CaO, it is obvious that here also we may have a garnet lying about half- way between two type species, in this case spessartite and andradite. Of the garnets that have been analysed none seem to occupy this intermediate position exactly, there being as a rule little difficulty in grouping them either as spessartite or andradite, although the mineral so called may differ widely from the theoretical composition. To obviate, however, this application of one of these names to a mineral that differs considerably in composition from the typical garnets, special names have sometimes been given; consequently there are 1 What is really meant in saying this is that mixed with the molecules of all the garnets may be a certain proportion of the molecules corresponding to spessartite, 2 Unless calderite be really a proper species corresponding to this formula, Cuap. VI.] MANGAN ESE-GARNETS. 163 several names, for varieties of garnets, that have no very explicit meaning and can usually only be applied to the garnet of the parti- cular locality for which the term was invented. If any one need a name for a garnet that he has analysed and finds to depart consider. ably from any of the type formule, he cannot as a rule use any of the existing varietal names, but is under the necessity of inventing anotner and increasing still further the number of these indefinite varietal names, Ther is a very simple way out of this difficulty, which would, if adopted, do away with the necessity for all these names. This consists in forming compound names expressing the position of a given garnet between two of the type species. Thus there is a garnet to which the name polyadelphite has been given. According to analysis 19 on page 443 of Dana’s Mineralogy this garnet can be fairly regarded as a variety of andradite in whicn a certain proportion of the CaO is replaced by MnO, Analysis 20 of another specimen of polyadelphite from the same locality, namely Franklin Furnace, N.J., U.S.A., contains, however, a much larger proportion of MnO replacing the CaO, whilst there is also a considerable proportion of Al,O, replacing the Fe,0;. Although the garnet is still closer in composition to andradite than to Spessartite, yet it differs considerably from the typical andradite and is in fact not so very far removed from being half-way in com- position between these two garnets. Instead of having a special name, polyadelphite, for this garnet it would be better to call it spessart-andradite, expressing the fact that it is really a compound of Re ee ely ran these two garnets. This could for brevity’s ‘ spandite ’. sake be contracted to spandite, If reference be made to the analyses! given in columns 3 and 4, on page 168, it will be seen that there is a considerable difference between the composition of the two garnets from the Vizagapatam District that these analyses represent. The Garbhém garnet has the RO group composed about equally of CaO and MnO and in this respect is about half-way between spessartite and andradite. In the RO, group, however, the Fe 203 is much larger in amount than the Al,Os, so that in this respect the garnet is fairly close to andradite in composition. It might then be thought that this garnet could be called a manganese-andradite. The Kotakarra garnet also 1 One of these is an actual analysis of the mineral, and the other calculated from the analysis of the rock in which it occurs. I y 2 164 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part 1. shows that the CaO and MnO are about equal in amount, but in the R203 group, the Fe,03, instead of being the predominant oxide, is very smallin amount, so that nearly the whole of the group consists of Al,03. In the same way, then, this garnet could be called calcium-spessartite. The two garnets are, however, indistinguishable in appearance, and both occur in the same series of rocks, namely the kodurite series. And if one were to go by the fact that they both react strongly for manganese one would call them both spessartite, this being par excellence the man- ganese-garnet. This in fact is what has been done in the previously published accounts of the manganese-ore occurrences of this district !, the garnet reacting for manganese and resembling very closely in colour some varieties of spessartite from the Central Provinces. I propose, therefore, to obviate this difficulty by the use of the term spandite for the manganese-garnets of the Vigazapatam district; any garnet from the manganese-bearing rocks of this area that gives a strong reaction fur manganese will be included provisionally under this term. If, how- ever, the term spandite be considered objectionable, then in view of what we know of the composition of these garnets there is no alternative to calling them manganese-garnet. The awkwardness of such a term is seen when it is desired to designate a rock by the names of its mineral constituents. Thus kodurite would be apatite-manganese-garnet-fels- par-rock. In this form it looks as if the rock contained four constituents, namely apatite, manganese, garnet, and felspar. This is particu- larly objectionable because amongst the mining community manganese- ore is frequently spoken of as manganese, manganese thus meaning in the locse parlance of the mining areas the mineral containing the element manganese rather than the element manganese itself. Hence in the fore- going example a mining man might understand that the rock was com- posed of apatite, manganese-ore, garnet, and felspar. On page 168, analyses are also given of two manganese-garnets from the gondite series of the Central Provinces. It will __Use of the term be seen that in both cases the group RO consists to ae a predominant extent of MnO, the lime being small in amount, so that from this point of view the garnets are to be regarded as spessartite rather than manganesian varieties of andradite. In the Wagora garnet the Rj03 group is all Al,O3. so that there can be no hesitation in calling this mineral spessartite. In fact this garnet, owing to the presence of nearly 10 per cent. of FeO as part of the RO iRec. G. 8. I., XXXII, p. 96, (1906) ; Trans. Min. Geol. Inst. Ind., 1, p. 87, (1906). Cuap. VI.] MANGANESE-GARNETS. 165 group, shows affinities to almandite rather than to andradite. In the Chargdon garnet, on the other hand, it will be seen that the R,03 group is composed of about equal parts of AloO3, Fe,0;, and Mn 03. In this respect it diverges considerably from spessartite. It is, however, very far removed from andradite, so that again there is no alternative to call- ing it spessartite ; unless one invents a special name for a garnet con- forming to the formula 3MnO.Mn,03.3Si09. this not bemg one of the six type garnets referred to on page 161. If such were done, we could say that the Chargdon garnet was intermediate between spessartite and this other type. Such a course is undesirable and consequently I have also called this garnet spessartite. I have, therefore, relying on these two analyses, used the term spessartite for all the manganese-garnets found in the rocks of the gondite series wherever they occur, namely in the Central Provinces, in Central India, and in N4rukot ; especially since, as far as one can tell from outward appearance, they are all the same in mode of occurrence, crystalline habit, and the fact that they react strongly for manganese. The differences of colour that they exhibit are to be ex- plained by the replacement of the manganese by iron and other elements to a varying extent and by the replacement of the Al,O3 by varying amounts of Fe,03 and sometimes Mn,0z. If reference be made to the analysis of a manganese-garnet from Boirani in Ganj4m, given in the fifth column on : en ot the term page 168, it will be seen that this garnet, which oo outwardly resembles some varieties of spessartite from the Central Provinces, is practically a variety of grossularite,- 3Ca0.A1,03.38102, with a small amount of manganese replacing a portion of the lime ir the RO group, and with nearly half the Al,O3 replaced by Fe,03. But as the RO group of andradite also consists of CaO it is obvious that this garnet can be regarded almost equally well as a variety of andradite with a little over half its Fe,0z re- placed by Al5O3. This garnet might therefore be equally well desig- nated iron-grossularite or aluminium-andradite, not considering for the present the small quantity of MnO present. To get over this difficulty, the mineral may very well be called, on the principle explained above, grossular-andradite, or for short grandite. If it be desired to express the fact that manganese is also present—this after all being the most impor- tant constituent from the economic point of view, as it is this that gives rise to the manganese-ores of Boirani—the garnet can be called manganese-grandite. From the point of view of brevity this term has of course no advantage over the term manganese-garnet and the term 166 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [Paxr 1: ‘ manganese-grandite ’ is open to the same objections, when it is neces- sary to use it in compound names of rocks, as “manganese-garnet’ is (see page 164). The difficulty cannot always be obviated, as in the present case, unless the mineral be called grandite without the prefix manganese’. The advantage of the term manganese-grandite lies, of course, in its explicitness. In view of what has been written above I propose to refer to the manganese-garmets of the different areas in India as :— 1. Spessartiie; im the rocks of the gondite series, 7.e., in the Central Provinces, Jhabua, and Narukot. 2. Spandite ; in the rocks of the kodurite series in the Vizagapatam district. 3. Manganese-grandiie, or more briefly grandite ; in the rocks, al- lied to the kodurite series, of the Ganjém district. 4. Aplome ; a special variety (see page 182). 5. Calderite ; in the massive garnet-rock of Hazaribagh ( see page 182). 6. Manganese-garnei ; in cases of considerable doubt as in pegmatites in the Central Provinces, where the character of the garnet has not been investigated, or in cases in which the mineral does not give a very marked reaction for manganese ; also sometimes in referring to any of the other garnets, to avoid the monotony in the constant repetition of the terms spessartite and spandite. I will now give below the analyses that have been made of Indian man- ganese-garnets. They are only twoin number. The hear devaiaie first was prepared for analysis by Mr. J. Coggin Brown by breaking up two or three trapezohedral crystals of spessartite from Chargion in the Nagpur district, and carefully picking out those fragments that showed no trace of oxy- alteration, the crystals being always altered to a certain extent along cracks. The specific gravity was determined on the picked material, but the figures were unfortunately lost. Specimens of garnet from this locality, however, usually give values for this constant ranging from 4-15 to 4-2 or a little over. The analysis was carried out by Mr. T. R. Blyth, the amount of material available for this purpose being not more than 3 a gramme, so that it was not possible to determine the state of oxidation of the manganese. The second also was picked for analysis ty Mr. Brown, who also carried out the analysis. The rock from which the garnet was obtained was a specimen of spandite-rock from thé Garbham mine in the Vizagapatam district, Madras. The material separated had a rich red colour and specific gravity as determined Cuap. VI. | MANGANESE-GAENETS. 167 by Penfield’s method of 4:02. Again the state of oxidation was not determined. The two analyses are given below :— Spessartite. Spandite. Chargaon. Garbham. Specimen No. 1030. Specimen No. A. 219. SiO02 : > A : 4 34°71 35°24 Al203 - ‘ - : 5 8°05 6:48 Fe203 ; 5 ‘ ‘ : 8°38 23°90 MnO A . : : 38:83 16°34 MgO ae 5°40 2-04 CaO * ; . s : 4°97 15°20 BaO : : ; = : Trace 0718 Ti02 : ‘ ; ‘ : ae Nil Moisture at 100°C. : : Nil Nil Combined water : : é Undet. Undet. 100°34 99-41 The analyses are given above as returned by the analysts. Since the state of oxidation had not been determined, I calculated the foregoing analyses into terms of the general formula 3RO.R203.38i09, assuming the state cf cxidation required for the constituents of the analysis to agree with this formula. The analysec thus re-arranged are given in the table on the next page. Tt will be seer that in the case of the Char- gdon garnet it was found necessary to add on 0-96 °/, of oxygen so as convert a portion of the MnO into MnoQz, whilst an excess of 3°00 °/, of MgO above the amount of constituents required for tke pro- toxide group has been excluded trom the re-arranged analysis. In the case of the Garbham garnet it was found necessary to add 0°26 °/, of Si0g, and to reject 0°27 °/, of oxygen, because a small portion of the Fe,0., had to be converted into FeO for the protoxide group. The interesting features of these analyses are first the presence of BaO in one case in traces and in the other to the extent of 0°18°/,, and secondly the existence, as deduced by calculation, of MngO3 in the R903 group in the Chargaon garnet, it being usually thought that all the manganese in garnets is present in the form of MnO. On pages 349 and 257 will be found analyses of gondite from Wagora in the Chhindwara district, Central Provinces, of opalized kodurite from Kotakarra in the Vizaga- patam district, Madras, and of opalized kodurite from Boirani in the Ganjam district, Madras; and further, an analysis of the garnet con- tained in each rock deduced by calculation from each rock analysis. These 5 garnet analyses, all calculated to 100, are given below. Their composition has already been discussed in connection with the nomenclature of the manganese-garnets on the preceding pages. 168 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: TABLE 17. Analyses of Indian manganese-garnets. = 1 | 2 | 3 4 5 | Lncelity | Chargdon | Wagora | Garbham | Kotakarra| Boirani eh \ 16 | Number | 1030 aay ie A. 219 A. 233 A. 134 984 | Specific gra- | | 4°24* 4°02 3°76* vity. | MnO , Eyl 30°81 24°48 16°46 16°50 2°68 FeO . ai] ce | 9°94 249 7°45 2°16 CaO . : 5°06 311 | 15°29 15°80 30°70 MgO . : 2°44 3°48 2°05 0°23 0°65 BaO . . oe tic 0718 ae fc Alp,O3 : 819 21°26 6°52 18°98 14°22 Fe203 2 8°52 o6 21°28 3°47 11°41 Mn203 =| 9°67 ots | ae =e Ss Si0e . : 35°31 37°73 | 35°73 37°57 38°18 100°00 100°00 100°00 100°00 100°00 Manganese . | 30°59 18°95 12°75 12°77 2°08 Iron 5°96 773 16°84 8°22 9°67 Nos. 1 and 2 = spessartite ; from gondite series, Central Provinces. Nos. 3 and 4 = spandite ; from kodurite series, Vizagapatam No. 5 = manganese-grandite ; from kodurite series, Ganjam. Nos. 1 and 3 are from actual analyses of garnets, and Nos. 2,4 and 5 calculated from analyses of rocks containing them. We can now consider the Indian manganese-garnets under the head- ings of spessartite, spandite, grandite, aplome and calderite. Spessartite. On the strength of two analyses, I am, as explained above, pro- visionally calling all the garnets found in the gondite series, 7.e., in the manganese-bearing rocks of the Central Provinces, Jhabua, and Narukot, by the Occurrence of spes- sartite. *Calculated. Cuap. VI. ] SPESSARTITE. 169 name of spessartite. In the Museum there are also some specimens of spessartite from Kulu, presented by Colonel G. Gordon Young. They are stated to have been found in mica-schist. Apart from this the only yet recognized occurrences of this mineral in India are in the gondite series in the areas mentioned above. As this is the characteristic mineral of this series of rocks it is to be found in nearly all the varie- ties of the gondite series, a list of the rocks of which will be found on page 329 ; it is to be understood that spessartite occurs in all those in the name of which the word gondite occurs, as well as in those rocks in the name of which it is explicitly mentioned. The typical occurrence is of course in the rock known as gondite, this being composed of spessartite and quartz. Frequently the rock is very fine-grained so that the individual garnets are not to be distinguished by the naked eye, but only with a lens, or in some cases only in thin sections under the microscope. On the other hand, the rock is often sufficiently coarse-grained for the crystalline form to be easily visible to the naked eye, the crystals being sometimes so large that they would have a diameter of one or even two inches across if they were whole. It is not necessary to give a list of all the localities for this mineral since it is found in nearly all the deposits associated with the gondite series ; and lists of these deposits in the districts of Balaghat, Bhandara, Chhindwara, and Nagpur, in the Central Provinces are given on pages 695, 735, 772, and 841. The only other localities are Kajlidongri in Jhabua, and Jothvad in Narukot, and the above-mentioned Kulu occurrence. By turning up the description of any particular deposit it will be found if spessartite occur at that particular place or not. At a few of these deposits spessartite has not yet been detected; as, for example, at Sitapar in the Chhindwara district. It will be as well to emphasize here the enormous importance of this mineral from the economic point of view. As shown Abundance and eco- on pages 293 and 353, a considerable proportion of nomic importance of 2 spessartite. the manganese-ores of the gondite areas has_ been derived from this mineral by chemical alteration. The consequence is that in the course of quarrying the manganese-ores large quantities of gondite and other rocks of this series are found in every stage of alteration into manganese-ore. The quantity of such rock in either the fresh condition or partly altered to manganese-ore is enormous, and the quantity of spessartite being thrown on to the dumps every year must run into thousands, if not into hundreds of thousands, of tons. I am not mentioning this as a fact to be regretted; for spessartite is at present a valueless mineral, although it often contains 20 170 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Parr I: to 30 per cent. of manganese. I merely mention the fact to emphasize what enormous quantities of this mineral exist in association with the manganese-ores of the Central Provinces. The importance of it to the mining man is as a prospecting indication. For if he find a piece of spessartite, or rock containing it, he should look for its source; for it may lead to the discovery of a body of manganese-ore with which it was associated. Although such enormous quantities of spessartite exist in India, it is a rare mineral in most other countries, except in small quantities. There are, however, a few localities outside India where it is to be found in fair abundance, as for example in the manganese-ore de- posits of the Queluz area, Brazil, and the spessartiferous rocks of Texas. The formation of the Indian mineral by the metamorphism of mangani- ferous sediments of Dharwar age is fully discussed on pages 288—292. When this mineral is found in coarse-grained rocks it usually shows more or less perfect crystals. Although I have not Localities for good given above a list of localities for this mineral in Eaciags India, I will give here the names of the localities at which the best crystals are to be found. They are :— Narukot State :— Jothvad. Bhandara district :— Hatora. Chhindwara district :— Bichua and Gaimukh. Nagpur district :-— Chargaon, Satak, and Waregaon. Kulu. At Jothvdd a band of spessartite-quartz-rock of coarse grain was found. On the weathered surface the garnets were seen to be orange- red and joined together in parallel growth. The crystal form is the thomb-dodecahedron, often distorted by growth along one axis into prismatic forms. At Hatora spessartite trapezohedra up to 4 inch diameter are found in amphibole-gondite. The crystals sometimes show minute hexoctahe- dral faces. At Bichua the garnet occurs in a pegmatite composed of white quartz and a white felspar lying between albite and oligoclase. The garnet where fresh is orange-red in colour, but sometimes dull brown-black due to alteration. The rock is intrusive into the gondite series. It is therefore not certain, though very probable, that this garnet is spessartite, for the GEOLOGICAL SURVEY OF INDIA. Memoirs, Vol. XXXVII, P17 Photo. by H. B. W. Garrick. Calcutta Phototype Co SPESSARTITE CRYSTALS (TRAPEZOHEDRA) WITH INTERSTITIAL QUARTZ. ON A BASIS CF MANGANESE-ORE. FROM WAREGAON, NAGPUR DISTRICT. NATURAL SIZE. ” iy Cm= oY Ta Pon tf J i ; “0st ee . Pe an i 1 i ‘ a in aL A 4 a tae 7 " ies, ‘ 1 , Pe yy le ec , a a 7% * ¥ 1 at y ' ‘ ae . 7 1 = et : r = ae | os ah MY \ / > f S Ay : uy j ff ’ 4, “ = ; Sat, be ae Ree Cuap. VI. ] SPESSARTITE, 171 reason that no analysis has yet been made of manganese-garnets in such pegmatites. The crystals are trapezohedral in form and if complete would often be 1 to 2 inches in diameter. One piece gave a value for G of 4:02, which is rather low for this mineral, although within the limits (see fig. 13). At Gaimukh the mineral is found in a rock containing a certain amount of quartz and rhodonite, with spessartite as the chief mineral. It occurs in beautiful trapezohedral crystals up + inch in diameter, the smaller crystals being a beautiful deep orange-red in colour, ard the larger ones blackish. The best locality of all is the pit known as the Kamthi Lady Pit, situa- ted at the eastern end of the Chdrgdon portion of the Mansar deposit. The occurrence is described on page 883. The garnets are often most beautiful trapezohedra, sometimes exhibiting all 24 faces, which are usually striated parallel to the faces of the dodecahedron. Fig. 14 on page 172 re- presents a garnet from Chargaon. Other faces to be noticed below are also sometimes seen. At Sdtak the garnets occur in garnet-rhodonite-rock very similar to that of Chargaion. They show trapezohedral faces, and if whole some of them would be 14 inches in diameter. The colour is yellowish black. Good crystals are also found in amphibole-gondite, although in this case they are smaller. At Waregdon I have obtained a considerable number of fine specimens of this mineral. Indeed, after Chargdon, it is the best locality ; but on account of the abandonment of the quarry, which is now filled with water, it is doubtful if any more specimens could be obtained, except by searching the dumps. These specimens consist partly of spes- sartite-rock and partly of spessartite-quartz-rock, the latter being the more favourable for the development of good crystals. The latter are, as usual, trapezohedra, occasionally showing dodecahedral and hexocta- hedral faces. Some of them if whole would be 14 to 2 inches in diameter. In colour they vary from deep orange-red to chocolate- brown, the latter being due to alteration (see figures 13, 15, 17, 18, 19 and Plate 7). The Kulu garnets are practically perfect dodecahedra up to nearly 4 inch in diameter and of a deep brown-red colour when whole. The specific gravities of two of them were found to be 4°11 and 4:16, respectively. That they are spessartite was confirmed by Babu Kiran Kumar Sen- gupta, who found one of them to consist almost entirely of silica and oxides of iron, manganese, and alumina (see fig. 16). 172 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ParTI: It must not, however, be imagined that the above are the only localities at which good crystals are to be found. I have myself also found them at several other localities; whilst Mr. E. L. Young showed me a large number of specimens of trapezohedral crystals obtained at the Lohdongri mine, Nagpur district, and Mr. C. E. Low has found good crystals of unusual form in Government Forest about one mile west of Kudsuri village in the Balaghat district. As will be judged from the above, the crystalline habit of this mineral er ieinecghis is characteristically trapezohedral (or icosatetrahedral), character. usuaily without any modifying faces (see fig. 13). The faces of the trapezohedron are, however, usually striated with a delicate series of lines, which are parallel both to the faces of the dodecahedron and to certain of the edges of the hexoctahedron. This is well illustrated by fig. 14, which represents a crystal of this mineral from Chargaon. It is the best crystal of this mineral I have found and is Fig. 13. Fig. 14. Fig. 15. Spessartite Crystals. Fig. 13.—Trapezohedron ; Bichua and Waregaéon. Fig. 14.—Striated trapezohedron; Chargdon. Fig. 15.—Trapezohedron and dodecahedron; Waregdon. nearly ? inch in diameter, showing all twenty-four faces of the trapezohe- dron. Another almost equally perfect crystal from the same place is inch in diameter. Sometimes, but only rarely, the corner A of the trapezohedral crystal is modified by the presence of the faces of the dodecahedron, d, or (110), asin fig. 15. These are usually small in propor- tion to the size of the trapezohedral faces, but in one case I found a manganese-garnet in which the latter faces were absent, the crystal being a simple dodecahedron (see fig. 16). This wasin a pegmatite composed of quartz, felspar, pale sea-green mica, and manganese-garnet, occurring near Kachi Dhéna, Chhindwara district. The garnet is of reddish brown colour, but on account of its mode of occurrence it is not known Cuap. VI. } SPESSARTITE. 173 whether this manganese-garnet is to be referred to spessartite. The Kulu garnets are, however, all dodecahedra without any modifying faces. The Jothvad spessartite noted on page 170 is also dodecahedral. In a few cases the corner A of the trapezohedron in spessartite is modified by the presence of the four faces of the hexoctahedron, s or (321), usually very small (see fig. 17). The garnets showing these faces are Fig. 16. Fig. 17. Fig. 18. Spessartite Crystals. Fig. 16.—Dodecahedron : Kulu and Kachi Dhana. Fig. 17.—Trapezchedron and hexoctahedron ; Bhui Hurki and Waregéon. Fig. 18.—Trapezohedron, dodecahedron, and hexoctahedron ; Waregaon. from Waregdon and Mandri in the Nagpur district, from Hatora in the Bhandara district, and from Bhui Hurki in the Balaghat district. The best examples of hexoctahedral faces are seen on some small orange trapezohedra on a specimen brought by Mr. A. Whyte from Bhui Hurki. The Waregaon crystals sometimes show the faces of the dodecahedron with the hexoctahedral faces bevelling the edges between the n and d faces, as in figure 18. According to Dana octahedral faces are very rarely OO Fig. 19. Fig. 20. Spessartite Crystals. Fig. 19.—Trapezohedron composed of vicinal hexoctahedral faces ; Waregdon. Fig. 20.—Octahedron. 174 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [Parrl: observed on garnets. I have not yet found any on Indian garnets.) Some crystals of a manganese-garnet of dark orange-brown to dark brown colour, up to 3 inch in diameter, and set in a matrix of quartz, were obtained by Mr. C. E. Low from near Kudsuri in the Balaghat district. Some of these crystals show a combination of the trapezohedron and dodecahedron, the two forms being about equally developed, whilst some show trapezohedral faces only. The garnet reacts for manganese, but it isnot yet known if the mineral is to be referred to spessartite. From what has been written above it will be seen that the common- est, and in fact the characteristic, form of this mineral is the trapezohedron, n, or (211); whilst faces of the rhomb-dodecahedron, d, or (110), and of the hexoctahedron, s, or (321), are not uncommonly found. I have seen no twinned crystals of Indian manganese-garnets. One trapezohedral crystal obtained from Waregdon shows that a few of its faces are really made up of vicinal hexoctahedral faces, one trapezohedral face being composed of two very flat hexoctahedral faces, as in figure 19. The crystals are usually about equally developed along all three axes ; but occasionally they are distorted. Thus the dodecahedral crystals of Jothvad (see page 170) tend to be prismatic. A crystal from Waregéon is very flat owing to being much more developed along two of the axes than the third. This crystal, also, indicates that the trapezohedral faces are composed of vicinal hexoctahedral ones. In one case I have noticed under the microscope what seems to be well marked cleavage, evidently parallel to the faces of the rhomb-dodecahedron, d, for these cleavages made angles of 60° with each other. The specimen in which this pheno- menon was noticed was a piece of gondite from the Kajlidongri mine, Jhdbua State. The fracture ol spessartite is very variable. Some- times it is sub-conchoidal, especially on unaltered examples. At other times it is irregular or uneven. Cleavage. 1 In one specimen—a piece of rock from Chargdon showing trapezohepdral crystals of spessartite set in a matrix of rhodonite, barytes, and a greer phosphate— {thought I had found an embedded octahedron of spessartite, with one corner, showing four faces, projecting, Hence the insertion of fig. 20. Later, feelirg doubtful, I broke up the specimen and found the supposed octahedron to be a trapezohedron, with the top corner (as oriented in fig. 13) projecting. Cuap. VI. | SPESSARTITE. 175 Very frequently the mineral breaks so as to show a zoned surface. This is found to be, not a true fracture, but usually the surface of contact with another crystal, the two having mutually stopped each other’s growth at the surfaces where they meet. These zoned surfaces are also often found at the contact of an imperfectly developed crystal with the quartz in which it is found. It is only with difficulty that this zoning can be obtained on a true fracture surface. When it is carefully examined it is seen to be due to a layered structure of the garnet parallel to the faces of the trapezohedron. This seems at first sight surprising because the striations so often seen on the faces of the trapezohedron, make it look as if the mineral were composed of lamelle parallel to the faces of dodecahedron, d. The case noted on page 174 of a crystal with its trapezohedral faces composed each of two vicinal hexoctahedral faces suggests, however, that the striations often observed on the trapezohedral faces of the Indian spessartites may really indi- cate an oscillatory combination with the hexoctahedron rather than with the dodecahedron. The striations are parallel both to certain of the edges of the hexoctahedron and to all the taces of the dodecahe- dron. The hexoctahedral interpretation agrees with the zoning. I have not particularly tested the hardness of the mineral; but it seems to agree with the values given in the text- books. The specific gravity of spessartite is given as 4-0 to 4°3 and I find that the few I have tested lie within these limits, tending to be from 4:15 to 4:25. The following show the actual values that have been determined for Indian spessartites :— Structure zoning. Striations. Specific gravity. Bichua . : ; ; ; 4:02; Chargaon (figured) . : : eee og Lo Kulu. ; ; 3 : . 4-11 and 4:16. This mineral exhibits considerable variety of colour, It is not very often that the crystals are perfectly trans- parent and free from darkening due to alteration ; but when the crystals are in this condition they are often of a most beautiful bright orange colour, and if they could be obtained in quantity and of a fair size they might be used as a most lovely gem. Frequently the colour is considerably darker than this, being then usually orange-red, the tint of which is often exactly the same as that of ordinary guava jelly. More rarely the colour is even Colour. 176 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Partl: darker, being occasionally almost blood-red. In one case at Hatora [ found a specimen showing a layer of this garnet resting on manganese- ore. The spessartite was of a colour that almost exactly matched that of crystals of potassium bichromate. Of the colours mentioned above the pure orange and the guava-jelly colour are about equally common, there being of course every gradation from one into the other. When the crystals are darkened due to alteration, the result is usually to give rise to deep reddish black colours, as in the crystal of garnet from Chargaon shown in figure 14. This is simply the result of the darkening of the true orange or orange-red of the unaltered mineral, owing to the presence in it of black oxides of manganese. Such crystals when boiled in hydrochloric acid so as to remove the oxides often assume a bright orange colour. Sometimes, however, the colour is a dark chocolate- brown due to the fact that the mineral has become very much altered throughout its substance ; when it has reached this condition the garnet is usually fairly soft and easily scratched with a knife. Occasionally large crystals are yellow in colour, as at Sdtak ; this is not, however, the colour seen through a good thickness of the transparent mineral, but only that seen through a small thickness at the surface, the underlying portions being altered. Since an orange mineral when seen in thin layers would appear to be yellow, it is probable that if this example from Sdtak were fresh and unaltered, so that one could look into it through a good thickness of the mineral, it would also appear to be of an orange or orange-red colour. The colours as given above are only those observed on crystals large enough to handle conveniently, 7.e., not smaller than } inch in diameter. But as seen in the fine-grained rocks containing this mineral the colour is often much paler, such as sulphur- yellow, pale yellow, cinnamon, and even greyish. Under the micro- scope also there is seen to be a great variation in the colour of spessartite. I should say that the most characteristic colour as seen thus .is a light yellow ; but sometimes the colour is as dark as bright sulphur-yellow, or so pale that the mineral is practically colourless, although the latter form is rare. In rarer cases the mineral shows some shade of brown in the yellow, and occasionally the colour is sufficiently dark to be called light orange. In very rare cases the mineral shows a distinct pink tint, but in such a case it may perhaps be doubted if the mineral is truely to be regarded as spessartite. A case in point is that of a manganese-garnet in gondite from Bichua. In the hand-specimen the mineral is of an orange-red colour, whilst under the microscope it is a salmon-pink, Cuap. VI.] SPESSARTITE. ilig’ This variation in the colour of spessartite, both in the hand-specimen and under the microscope, is very interesting, as it points to a great variation in the composition of the mineral. It would be very interest- ing to analyse a series of specimens of this mineral to find out what 1s the connection between the colour and composition. It would probably be found that the main factors in producing this variation in colour are the relative amounts of manganese and iron. It is further interesting to note that not only does the colour of this mineral vary from one crystal to another, but that often there is a great variation between the colour of the outer and inner zones of the same crystal. I have not actually noticed this macro- scopically, but it isa common phenomenon under the microscope. Thus the pink example from Bichua referred to above is nearly colourless in the centre ; whilstin a specimen of gondite from Kodeg4on, the garnets are sometimes sulphur-yellow throughout, and some times colourless in the centre and yellow on the outside, this latter phenomenon being very frequently observed. In an example from Jothvdd the mineral is yel- low and light brown in patches, tending to be yellow towards the centre, Another cause of variation in the colour of spessartite is inclusions. The normal colour of a piece of typical gondite, 7.e., the fine-grained rock composed of spessartite and quartz, is a fairly light colour, especially some shade of yellow, cinnamon, or grey. But sometimes the rock shows purplish or reddish tints, as in cases from Hatora and Ukua. Under the microscope this colour is found to be due to the presence in the centre of each garnet grain of a cloud of very finely divided red dust, which is probably ferric oxide or hematite. Such rocks are often banded, some layers being reddish or purplish due to the presence of these inclusions, and some of them of the normal light colour of gondite, the garnets in such layers being found under the microscope to be free from the inclusions found in the other bands. In some of the Chargéon garnets definite inclusions of red hematite are seen under the microscope, as well as brown films, perhaps of limonite; the hematite inclusions were probably formed at the same time as the garnet, and probably express the fact that there was a small surplus of ferric oxide over that required for the formation of the garnet. The limonite films, on the other hand, occupy cracks, and, presumably, were introduced subsequent to the formation of the garnet. Hematite also occurs in patches in spessartite in gondite from Kajlidongri. Spessartite is sometimes quite free from inclusions ; but it more ofteu contains them, either of the kind noticed above, or of other kinds. I N Colour zoning. Inclusions. 178 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: One of the commonest of these is a colourless highly refracting mineral, which is probably apatite. Black inclusions are also sometimes present. These may represent a residue of manganese oxide over that required for the formation of the garnet, similar to the case of the hematite inclusions mentioned above. Spessartite, belonging to the isometric or cubic system like all Anomalous double the garnets, should be isotropic, 7.¢., remain refraction. dark as viewed between crossed nicols during a complete revolution under the microscope. Many garnets, however, exhibit anomalous double refraction, and the Indian spessartites are no exception in this respect. This phenomenon, which is considered to be of secondary origin, is most often seen in the spessartite of Kajlidongri, and causes the part of the crystal exhibiting it to polarize in a very low grey, in which there may bea yellowish tinge owing to the superposi- tion on it of the yellow colour of the garnet. The whole of the spessartite is sometimes affected by this phenomenon, the garnet then being split up into small areas of different optic orientation as if it were an aggregate of different individuals. In places it shows signs of interference crosses, which in some cases are very distinct. In one case where the garnet was zoned, colourless inside and yellow outside, the colourless portions showed anomalous double refraction to a much less marked degree than the yellow portions. Of the characters of this mineral observable under the microscope in thin sections, the colour and anomalous double refraction have already been discussed. The other noticeable features are :—the high index of refraction, causing the min- eral to stand up in the sections and to exhibit very pitted surfaces ; and the great tendency to idiomorphism that it displays. When the whole rock is composed of spessartite, the separate garnets mutually interfere with each other; but when there is another mineral, such as quartz, to act as a cement to the garnet, the latter shows its crystal outlines, which are usually polygonal. The garnets are then about equally developed in all directions and are doubtless almost always the cross sections of trapezohedra. When rhodonite is present the garnet is almost invariably idiomorphic with regard to the rhodonite in which it is often enclosed. Occasionally, however, the relation of these two minerals is reversed. In one case, namely in a rock from Kajlidongri, the garnet seems to have been formed later than the quartz ; for it includes the latter, so that the garnet forms the meshes of a net Microscopie aspect. Cuap. VI. ] SPANDITE. 179 surrounding the separate grains of quartz. The alteration of this mineral is discussed on another page (354), and is illustrated by figures 1 and 2 on Plate 12; whilst the form of the mineral as viewed under the microscope is illustrated by figures 1 to 3 of Plate 11. Spandite. As already explained (page 163), ‘spandite’ is a name proposed for the varieties of manganese-garnet that are intermediate in position, as regards composition, between spessartite and andradite. An ideal specimen of spandite would contain about equal proportions of manganese and calcium in the protoxide group and about equal proportions of iron and alumi- nium in the sesquioxide group. Analyses are given on page 168 of two specimens of spandite from the Vizagapatam district, and since these are considered to be representative of the whole of the manganese-garnets occurring in the kodurite series of this district, I propose to designate all the manganese-garnets found in this series by this name. At pre- sent, moreover, no analyses of manganese-garnets have been made that justify the application of this name to manganese-garnets outside this district. Consequently the mode of occurrence of this variety of garnet will be best understood by reading the account of the kodurite series given on pages 243—255. The characteristic rock in which this mineral is found is the one I have designated kodurite. This consists of potash-felspar, apatite, and spandite. Often quartz is present as well, the rock then beg quartz-kodurite ; whilst sometimes the garnet forms practically the whole of the rock, which is then known as spandite-rock. The best locality for span- dite-rock is Kodur. As explained on page 247, the rocks of this series are supposed to be of igneous origin, and as the spandite is con- sidered to be an original mineral, this origin must also be ascribed to it. Not only is it found in the rocks of the kodurite series, but it is frequently present in the ores that have been formed during the chemical changes that have affected the rocks of this series since their formation, with the production of merchantable manganese-ores. In these cases - it often appears as bright red garnets set in a matrix of manganese-ore, usually psilomelane. On Plate 8, fig. 4, is a photo-micrograph of such ore. showing the psilomelane growing at the expense of the garnet. The best localities for such specimens are Garbhdm and Ramabhadrapuram (Mamidipilli). The following is a list of the. I n2 Composition. Occurrence. 180 MANGANESE DEPOSITS OF INDIA: MINERALOGY. | Part lI: localities at which manganese-garnet has been found in _ this district :— Avagudem, Chintelavalsa, Devdda, Kantikapilli, Kodur, Kotakarra, Garbham, Mamidipilh. Perapi, Sandapuram, and Taduru, If this list be compared with the list given on page 1047, of locali- ties at which manganese-ore is found in this district, it will be seen that there are some localities at which spandite has not yet been found. This is probably only on account of the deposits not having been sufficient- ly opened up. Later on this garnet will doubtless be found in all these deposits, except ones ihat are purely detrital, such as Garividi. Probably owing to its igneous origin, from which one would expect a greater uniformity of composition and consequently a greater constancy of physical characters than in garnets of metamorphic origin, this mineral is much less variable than the spessartite of the Central Provinces. In size it is fairly uniform, seldom ranging outside the limits of ,4, and } inch in diameter. In spandite-rock, e.g., at Kodur, it occurs in granules averaging } to } inch across. In this rock the granules are all pressed one against the other, so that they are bounded by flattish faces that do not, except perhaps occasionally by accident, conform to any particular crystallographic direction. In kodurite the spandite individuals, which are usually about yg tod inch in diameter, are found both aggregated and as separate granules. These granules are either well rounded, or are partly bounded by small unrecognizable faces. They often show brilliant reflections both from the faces mentioned above and from fractures, the lustre being vitreous in the former case and resinous in the latter. The spandite varies in rocks from differ- ent localities from deep orange to orange-brown, orange-red, and _blood- red, and never shows the yellow and lighter orange colours of the spes- sartite of the Central Provinces. Under the microscope these garnets show various tints of pale yellow, pale orange, and pale orange-brown, a brownish tint being much more often seen in spandite than in spes- sartite. One mineral with which it may easily be confounded is the pyroxene mentioned on page 137, found in the manganese-pyroxenites. It is often impossible to determine without recourse to the microscope whether a particular grain in one of these rocks is a garnet or a pyroxene, so similar are they in their size, indefinite form, and orange- brown colour. Characters. Cap. VI. | GRANDITE. 181 The specific gravity of this mineral is considerably lower than that of spessartite, lying, as might be expected, between that of spessartite and that of andradite. The specific gravity of spessartite is given by Dana as 4:0 to 4:3, and that of andradite as 3:8 to 39. The one actual determination of the specific gravity of spandite is that of the speci- men from Garbham of which the analysis is given on page 168. This value is 4:02. The alteration of this mineral is considered on pages 265—6; and 1s illustrated by fig. 4 of Plate 8 The figures 1 to 4 of Plate 8 illustrate the occurrence of this mineral. The minerals with which it is associated at various localities can be seen from the account ot the minerals of the kodurite series given on pages 250—3. Grandite. As explained on page 165, this name has been proposed for those garnets intermediate in composition between grossularite and endra- dite, so that the typical grandite would have its RO or protoxide group composed entirely of CaO, and its R203 or sesquioxide group of about equal amounts of Al)O3 and Fe203. An analysis of an Indian yarnet corresponding very closely to this ideal composition is given on page 168. It also contains a small amount of MnO, namely 2°68%. This amount of one constituent would, as a rule, be insufficient to require noticing in the name of a garnet. It so happens, however, that this is the most important constituent of this particular garnet, because it is from this small amount of manganese that the associated manganese- ores have been derived. Hence this mineral can be called manganese- grandite. But I shall refer to it merely as grandite. It is found at Boirani in the Ganjam district, in a rock composed, when fresh, of ortho- clase-felspar, garnet, and a little apatite, the latter being only visible under the microscope. Although I cannot be certain that this rock is genetically related to the kodurite series of the Vizagapatam district, yet the resemblance to the typical kodurite is close enough to justify a provisional inclusion of the Boirani rock in this series. The only difference is in the composition of the garnet, the Boirani garnet containing only a small quantity of manganese, whilst the Vizagapatam garnets are highly manganiferous. The Boirdni garnet is cinnamon- coloured in the hand-specimens, and is usually about 3'5 to ;'5_ inch in diameter. Under the microscope it is yellow in colour. Since much attention has not been given to this garnet, there is little to say about 182 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: its characters. The only specific gravity value available is the one calculated from the analysis of the opalized garnet-felspar-rock given on page 257. The value so calculated is 3°76, and is intermediate between the value given by Dana for grossularite, namely 3°55 to 3°66, and that given for andradite, namely 3°8 to 3°9. At Nautan-Barampur, also in the Ganjam district, there is an occurrence of a rock composed of rhodonite, a manganese-garnet, and blue apatite. The garnet is sherry-coloured and very similar in appearance to that of Boirdni. It has not been analysed, so that it cannot vet be stated if this is another occurrence of grandite. Aplome. This is a name given by Haiiy to a variety cf andradite that had its dodecahedral' faces striated parallel to the shorter diagonal of the thombs instead’ of, as is customary when striations are present, the longer diagonal. »,The one analysis given by Dana of a specimen from Altenau happens to be manganiferous, containing 3°02% of MnO; but it is apparently not known if these striations necessarily indicate the presence of manganese; for the aplome of the other localities does not seem to have been analysed. The only record of aplome in India is con- tained in E. Balfour’s catalogue of the Rev. Mr. Mazzy’s Madura collection of minerals!, and in J. H. Nelson’s more detailed account of the same?. The latter mentions the occurrence of aplome near So- lavandan, about 12 miles west of Madura, and near Melavalavu, about 20 miles N.-E. of Madura. This record is to be considered doubtful in the absence of any account of how the mineral was identified. Calderite. In 1850 H. Piddington published a paper in the Journal of the Asia- tic Society of Bengal, Vol. XIX, pp. 145 to 148, entitled ‘On Calderite, an undescribed Siliceo- Tron-and-Manganese-Rock, from the district of Burdwan’. From this paper it appears that he obtained specimens of the rock to which he has given this name from ‘Kut-Kumsandy 12 miles N.-W. of Hazaribagh,’ as well as from the Burdwan district ; But the particular part of the latter district from which the specimens 1 Catal., Govt. Central Mus., Madras, p. 3, (1855). 2 *'The Madura Country ’, pp. 14, 27, (1868). Occurrence. Cuap. VI. ] CALDERITE. 183 were obtained is not specified. He distinctly states that calderite is a rock composed of two minerals. One of these is quartz, the other being a mineral which, to judge from his descriptions and the analysis he gives, must be a garnet. The hardness of the rock that he analysed is given as 7 to 8 and the specific gravity as 3°65, the garnet being evidently the principal mineral and the quartz only present in comparatively small amount. As the fresh fracture of the rock is described as being exactly like biack rosin, whilst splinters are described as being ‘sometimes highly translucent like dark brown rosin ’, it is evident that the garnet must have been one of the very dark brown varieties approaching melanite in appearance. In fact, in a subse- quent paper 3, in which he describes a series of specimens of calderite, ranging from quartz containing only a small amount of the garnet up to rocks probably entirely composed of garnet, he particularly says, regarding the rock composed mostly of quartz, that the iron and manganese mineral in the rock is ‘seen only in small and mipute rounded specks like Melanite garnets ’. In the former paper he gives the following analysis of the rock com- posed mostly of the garnet :— Silex - 3 : ‘ ? . 46°35 Alumina . A ; ‘ ; : , 0°35 Lime 5 d ‘ : ; : : 1:00 Arsenic . 5 : ; : f = (0:26 Perox. Iron. F i ‘ 2 3018 Protox. Manganese . : ; : =) 2-00 99-08 Loss, partly fluorine, of which there are traces 0°92 100-00 Sas Mallet, in discussing this analysis in his Mineralogy of India, p. 90, notes that the excess of silica above that which would be present in a garnet may be due to the quartz that Piddington says was disseminated through the speci- men. He also remarks on the fact that the ratio of peroxides to protoxides is quite wrong for a garnet, and on this account ‘ and the inaccuracy of one or two other analyses by the same authoz * regards the above analysis as very doubtful. This is an unnecessary Composition. 1 Jour. As. Soc. Beng., XX, pp. 207 to 210, (1852). 184 MANGANESE DEfOSITS OF INDIA: MINERALOGY. [ Part l: assumption. It is probable that in carrying out the analysis Piddington weighed the iron as Fe 203, and the manganese as Mn30,4, and that he assumed the iron to be present in the rock as Fe 03 and the manganese as MnO. In fact he probably omitted to determine the amount of available oxygen in the rock. Had he done this he might have found that a portion of the iron was present in the protoxide form, giving the correct ratio of peroxide to protoxide for a garnet, On the supposi- tion that the analysis is substantially correct, only lacking the determination of the available oxygen, it can be re-arranged mineralogi- cally as follows :— Garnet :— MnO : : z 4 . 21:00 CaO : 3 A : 5 1-00 FeO : : 5 3 - 7°56 AlgO3 . ; E > (0:35 Fe.03 st. : : 5 2. ATS SiOz : : - : . 228 76°97 76°97 Quartz . é : ; ; 2 22107 Oxygen. é : : : : pel Ones Arsenic. z : 2 : 3 e020 Loss . F ; * : 5 =) 10392 100°09 The 0°84% of oxygen left over according to the foregoing interpre- tation was not, of course, determined to be piesent, and is to be regarded as another part of the undetermined constituents. If this in- terpretation be the correct one, then it is evident that we have here a garnet corresponding to the formula 3MnO.Fe,03.38i09. None of the six type garnets possesses this formula, so that it seems possible that a seventh is to be added to the six garnets at present recognized. It will be desirable to use the term calderite to describe this garnet rather than the whole rock. Mallet has in fact already used this term as the name of a mineral rather than of the rock in which it occurs. But he has unfortunately used it, in his Mineralogy, page 89, for a garnet that con- tains only traces cf manganese, as well as for the highly manganiferous garnet to which it properly belongs. He says: ‘In the metamorphic rocks of the Hazaribagh district irregular beds of massive garnet, some- Cuap. VI. | OAL DERITE. 185 times of considerable thickness, are met with’. He refers to this mas- sive garnet as that which Piddington called calderite, and gives an analysis by Tween showing only traces of manganous oxide, but showing on the other hand a large percentage of lime. The analysis shows that the garnet analysed approaches sufficiently near to the theoretical com- position of andradite to be called by that name. The name calderite is therefore wrongly applied to this garnet; unfortunately this mis- take has been repeated in Dana’s System of Mineralogy. I have been able to find in the collection of the Geological Survey of India one speci- men of calderite labelled ‘A. S. B.’. This means that it formed part of the collection of the Asiatic Society of Bengal; and it is presumably one of the specimens that were examined and described by Pidding- ton. The rock is composed almost entirely of garnet and in fact could be described as massive garnet. In the hand-specimen it is a dark resin-brown as looked at from a little distance. When examined closely, however, it is seen to be of a rich orange-brown wherever a crack renders a portion of it transparent. There is some red in the colour of this mineral, so that it looks very like some specimens of spandite in appear- ance. I tested it for manganese, and found that it zeacts distinctly but not strongly for this element, so that the Piddington’s analysis was either made on a piece of different composition, or Mallet’s supposition as to its inaccuracy is correct. In places the specimen contains a dark green pyroxene. It is obvious that it will need a careful analytical examination of this garnet before it can be considered proved that it is a manganese-iron-garnet conforming to the formula 3Mn0.Fe,03.38i109. During 1906 a specimen was received in the Geological Survey Office of a rock from Sirsia, 54 miles N.-E. of Kharagdiha, in the north- ern part of the Hazaribagh district, the sender being Mr. J. W. Boilard. The rock seems to be similar to that mentioned by Mallet’ as being found in the bed of the Patru nadi, N.-E. of Gulgo, in the north part of the same district. He describes it as a mixture of garnet and cocco- lite containing traces of galena and copper. He refers to the garnet when it occurs in the massive form as calderite. Mr. Boilard’s speci- men consists essentially of a mixture of a rich brown garnet and a bright green pyroxene, with galena present in parts of the rock, sometimes in abundance and sometimes only sparingly. Under the microscope the garnet is seen to be brownish pink in colour and the pyroxene very 1 Ree. Geol. Surv. Ind., VII, p. 34, (1874). 186 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [Part I: pale bluish. On testing it is found that both minerals react for man- ganese, the garnet very strongly, and the pyroxene distinctly, but not strongly. It seems probable that both this and the case mentioned by Mallet are occurrences of calderite. From its colour the pyroxene may be suspected to be related to the manganese-pyroxenes of the blanfordite type. The galena has been introduced subsequent to the formation of the rock by the process of metasomatic replacement. Along cracks the garnet is usually finely crystalline, showing faces of the rhomb-dodecahedron. CHAPTER VII. MINERALOG Y—continued. Silicates (contd.)—Epidotes, Micas, etc. Piedmontite—Ilvaite—Carpholite—Manganese-micas—Manganchlorite?—Mangano- phyllite—A lurgite-—Ottrelite. Piedmontite. The characters of this mineral as given by Dana are summarized below :-— It belongs to the monoclinic system, crystallizing in prismatic forms isomorphous with epidote, of which it is the man- ganese variety. Also found massive. Cleavage ce perfect; aless so. Fracture uneven. H.=6°5. G.=3°4 to 3°52. Lustre vitreous. Colour reddish brown and reddish black. Streak reddish. The most striking character of this mineral is its beautiful pleochroism as seen in thin sections under the microscope. The pleo- chroism scheme varies in specimens from different localities, but is generally— Characters. a = yellow to orange. b = amethyst or violet to rose. ¢ = rose to carmine. In composition the mineral is a basic orthosilicate conforming to the formula Caz(AlOH)(Al,Mn,Fe),(Si04)3 or H,0.4Ca0.3(Al,Fe,Mn):03.6Si0,. The amount of manganese oxide, Mn.0s, in the published analyses varies from 4°52 to 15-00, corresponding to 3°5 to 10°5% of manganese. This mineral cannot be considered a common one ; it is found in the crystalline schists of Japan, in the altered pre-Cambrian rhyolites of Maryland and Pennsylvania in the United States of America, and in Piedmont, Brittany, and England. Ordinary epidote may be manganiferous, but this mangan-epidote is to be distinguished from true piedmontite by the fact that it is, like epidote, optically negative, whilst piedmontite is optically positive. Such mangan-epidote is found at Jakobsberg in Sweden, and it is the analysis of this mineral that gives the lower limit for Mn gO, given above. Mangan-epidote. 188 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Parr I: Other epidotes that have pleochroism schemes similar to those of _piedmontite are thulite and withamite. Thulite is a variety of the orthorhombic epidote, zoisite, and does not contain manganese. In fact no orthorhombic manganese-epi- dote seems to be known. Withamite is a variety of ordinary epidote containing a very small percentage of manganese. It is found at Glen- coe in Scotland and an analysis by Heddle showed only 0:14% of MnO. The pleochroism schemes of thulite and withamite are shown below :— Thulite and withamite. Thulite. Withamite. a = light rose. a = lemon-yellow, b = deep rose. b — light rose. ¢ = yellow. t= strong rose, It will be seen from this that the pleochroism tints of these two minerals are similar, except that the colours for the a and ¢ axes of withamite, which corresponds in pleochroism to piedmontite, are interchanged in thulite. It is obvious from what has been written above that it must be a matter of considerable difficulty to settle, merely Distinction between from the examination of thin sections under the the different mangani- : ; : ferous epidotes. microscope, whether the mineral is one of the epidotes, withamite or thulite, containing little or no manganese, or whether it is one of the more manganiferous ones, piedmontite or mangan-epidote. But a test for manganese, made on a small carefully picked chip of the mineral will be sufficient to settle this point. For if a decided reaction for manganese be obtained the mineral cannot be thulite or withamite, but must be either piedmontite or mangan-epidote. It is more likely to be piedmontite, because this is much commoner than mangan-epidote, but as noticed above the only way to determine this point is to determine the sign of the mineral, a positive sign characterizing piedmontite and a negative mangan-epidote. The investigation of the Indian manganese-ore deposits has led to the discovery of this mineral at several locali- ties in the Archean schists of the areas where the rocks of the gondite series are found. The following is a list of localities :— Central Provinces— Nagpur district :--Ghogara, Junapani, Junawani, Maharkund, Mohugaon, Pali, Rajkota. Central India— Jhabua State :—KéAjlidongri. Bombay— Narukot State :—Jothvad. Occurrence in India. Cuap. VII. | PIEDMONTITE. 189 Although this mineral is found only in areas in which rocks of the gondite series occur, it does not usually occur actually in the rocks of this series, but rather in the crystalline limestones of the same neighbourhood. Thus in the Nagpur district the mineral occurs in association with erystalline limestones at all the localities except Maharkund, where the mineral was found in loose blocks of epidote-rock. At Kajlidongri and Jothvad, on the other hand, some of the occurrences of piedmontite are in rocks intimately associated with the rocks of the gondite series. Below I give a list of the rocks in which piedmontite occurs at each of the known localities :— Ghogara :—As granules and nodules, both in gneiss, composed of quartz, felspars, and some sphene, and in crystalline limestone ; some specimens show a :passage from gneiss into limestone, by the chemical replacement and alteration of felspars with the production of calcite (see Plate 10, figs. 3 and 4). Junapini, Junawdni, and Rajkota.—As granules, in crystalline lime- stone containing quartz and mica (phlogopite?). Mahdrkund :—As fine-grained patches in epidote-rock, the rock, which was found in loose blocks, probably occurring in situ in associa- tion with crystalline limestones or pyroxenic gneisses. Mohugdon :—As granules, in crystalline limestone containing also a small amount of quartz and sphene. Pali :—As granules and small patches, in crystalline limestone usually containing quartz, and in fine-grained granulitic gneiss containing quartz, plagioclase, orthoclase, mica, apatite, sphene, and sometimes spessartite and a colourless amphibole (see Plate 10, fig. 2). In the latter rock there is often present a certain proportion of calcite of secondary origin forming at the expense of the felspars. Kailidongri :—The mineral occurs here under two distinct circum- stances. (1) One occurrence is in a rock composed of spessartite, quartz, plagioclase, and orthoclase (?), the rock being a part of the ore-body and in processof conversion into manganese-ore. (2) The otheris that mentioned on page 680 and illustrated in fig. 1 of Plate 18, where the mineral has been developed on the schistosity planes of some serici- toid phyllites, in the part of a sharp fold into which these rocks have been thrown where the pressure was obviously most intense, the other por- tions of the rock being free from this mineral, 190 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part: Jothvdd :—At this place several specimens of rocks containing this mineral were collected, and are as follows :— (1) Crystalline limestone containing spessartite, rhodonite, and piedmontite. (2) Spessartite-calcite-quartz-rock containing apatite, wolla- stonite, piedmontite, and a lavender-coloured mineral not yet identified. This rock might be called a calciphyre. (3) Banded rock of which one layer, 1-inch thick, consists of apatite-spessartite-piedmontite-rock, the latter being the most important constituent. (4} As black crystals of piedmontite associated with white quartz, lining a vein-lke cavity traversing the remainder of the rock, which consists of bands of apatite-spessartite- piedmontite-rock and of spessartite-quartz-rock, containing apatite, piedmontite, and pyroxene. (5) As rose-pink patches in granite at the place where it has absorbed portions of the rocks of the manganiferous series. I have examined slides of all these rocks under the microscope and find that they exhibit the colours characteristic of manganiferous epi- dotes. Considering their associations it is improbable that any of them are withamite or thulite ; for they must all be manganiferous, except perhaps the Maharkund occurrence. I have not yet been able to exa- mine them carefully enough to determine their sign and thus settle if any of them are to be called mangan-epidote rather than piedmontite. In most cases it will probably be a matter of extreme difficulty, because only chance sections of the mineral obtained in microscope slides will be available. In a few cases at Pah the pleochroism tints are pale, and it then seems possible that the mineral is only a variety of com- mon epidote containing a small quantity of manganese. Provisionally, however, I propose to group all these occurrences under piedmontite. In one case only have I observed definite crystal faces. This is in the Jothvdd rock, No. 4, where the mineral lines what seems to be the two sides of a veinlet. The crystals are up to } inch longand one especi- ally good example shows faces that are, as far as can be determined without actual measurement, the following :—a (100), c (001), and + (101), forming a prism parallel to the b axis, terminated at one end by faces that may correspond to the prism m(110) and one of the Characters of Indian piediiontite. Cuar. VII.] . PIEDMONTITE. 191 pyramids. The mineral, when not crystalline, usually occurs as dis- seminated grains, especially in the crystalline limestones and the gneisses associated therewith, and as nodules, also in the crystalline limestones. In these limestones the piedmontite nodules are usually associated with nodules of manganese-ore, and sometimes a nodule of manganese-ore is bordered with a thin rim of piedmontite, as in Plate 14. The origin of these limestones and gneisses is discussed on pages 298—302. In the phyllite of Kajlidongri the mineral occurs in the form of small prisms. In colour the mineral varies from black. as in the crystals of Jothvad, to dark reddish-black and deep crimson, the latter colour being best seen in the piedmontite nodules found at Ghogara. In these nodules, which are often as much as 3 inches long, the piedmontite is sometimes in parallel fibres, so that the mineral has then some resemblance to erimson silk. In the first of the Kajlidongri rocks the mineral may be described as being of a pansy-purple colour. The colour under the microscope is very striking, consisting of various shades of yellow, orange, red, pink, amethyst, magenta, carmine, and even blood-red, the latter being an exceptional colour. Some of these colours are, of course, not true axis colours, the colour seen in any random section under the microscope being usually compounded of all three axis colours in varying proportions. In a few cases I have worked out the pleochroism scheme. These are given below :— 2 b c G@hogara Canary yellow Salmon to pale pink Amethyst to carmine or rose. Mohugéon Patchy yellow and Burnt sienna to clove- Amethyst to carmine. orang?. brown. Jothvad No.1 Deep orange-red Very deep red with ame- Deep amethystine or crimson thyst tinge. lake. Jothvad No.2 Orange to orange- Magenta ordeep ame- Brownish lilac to reddish scarlet. thystine. chestnut. Ka4jlidongri No.1 Orange to brown- Vioiet-rose with a brown- Magenta to rose. ish orange. ish tinge. The above determinations should be regarded as provisional only and liable to modification when the Indian piedmontites are more carefully examined. The other characters noticeable under the microscope are the high index of refraction, and the very high double refraction, although this is difficult to observe, except in extremely thin sections, owing to the strong colouration of the mineral. Further the mineral is often twinned. 192 MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ Parrl: Ilvaite. This is a black orthorhombic mineral of specific gravity about 4 and hardness 5°5 to 6. Itisa sub-silicate of the formula CaFe’’oFe’’’Si,0b, in which a portion of the ferrous iron is usually replaced by manganese. The analyses given by Dana show 0°74 to 866% of MnO. Ilvaite has not yet been identified in association with the manganese-ore deposits of India. But it is mentioned in E. Balfour’s catalogue. of the Rev. Mr. Muzzy’s collection from the Madura district 1 that it has been found in this district; he says ‘ YENITE, is abundant, com- posing a cliff in a small mountain, some three or four miles in length, Madura.’ Whilst J. H. Nelson 2, in giving an account of Muzzy’s collection, records the occurrence of crystallized, massive, and granular yenite, and a variety of lievrite near Puda-kudi, about 22 miles N.-W. of Madura. Yenite and lievrite are old names of this mineral, now no longer used. The record of the occurrence of the mineral given above is to be considered doubtful. Carpholite. This mineral is a hydrous sub-silicate corresponding to the formula 2H:0.Mn0.A1,03.2Si02, in which a portion of the alumina may be replaced by ferric oxide and a portion of the manganese protoxide by small quantities of lime and magnesia. It is usually found in radiate and stellate tufts of some shade of yellow, typically a straw-yellow. It is a rare mineral, originally found in the Schlackenwald, Bohemia, but since discovered at a few other localities. This mineral has not yet been definitely identified in India. But at Kajlidongri a bright yellow mineral is found in little veinlets, 2 to 4 inches thick, that traverse the ore in cross-cut 7 (see Plate 19). These veinlets consist of quartz, albite-felspar, and this yellow mineral, with a certain proportion of crimson mica in places. The rock has become largely manganized, perhaps by replacement effected by manganese- bearing solutions. The yellow mineral looks like yellow asbestos and seems to be soft ; but this is probably because, on testing such a finely fibrous mineral, the fibres are easily broken. In appearance the mineral resembles carpholite more closely than any other mineral in the col- lection of the Geological Survey of India. I made a qualitative analysis of it and found that it contained silica, iron, aluminium, TOA EAEEEES 1 atal , Govt. Cait Mus., Madras, p. 9, (1855). 2 «The Madura Country ’, pp. 15, 27, (1868). Cuap. VII. ] MANG ANESE- MICAS. rf 193 calcium, and a trace of magnesium. The amount of manganese does not seem to be very large, whilst the Al,O3 is probably less than the Fe Os in amount, and the amount of CaO is considerable. Water, however, seemed to be absent. But for the latter fact the mineral might have been regarded as a variety of carpholite in which a large portion of the MnO was replaced by CaO and a large portion of the AlyO3 by Fe Oz. I have mentioned this mineral in this place because of its outward resemblance to carpholite, but recognize that when it is analysed it will probably be found to be a different mineral, perhaps even one of the yellow manganiferous amphiboles. In E. Balfour’s catalogue of the Rev. Mr. Muzzy’s coliection of minerals and rocks ! there is a record of the occurrence of this min- eral in the Madura district; whilst J. H. Nelson 2 im giving a more detailed account of Muzzy’s collection, mentions the occurrence of ‘karpholite’ near Puda-kudi, about 22 miles N.-W. of Madura. This record is to be considered doubtful. Manganese-micas. Very little work seems to have been done on micas characterized by the presence of a quantity of manganese sufficient to produce any appreciable effect on the physical characters of the mineral. Nearly all the micas may occasionally contain a small amount of MnO, but this rarely affects the colour or other properties of the mica to an apnreciable extent. There are, however, three micas containing manganese, to which separate names have been given. These are manganophyilite, caswellite, and alurgite. In this place we will also consider the mineral known as manganchlorite, as it is difficult to tell from altered varieties of manganophyllite. Manganophyllite is a manganiferous variety of biotite found at Pajsberg, Langban, and probably Jakobsberg, in Sweden. Its formula may be represented as follows :— (H,K)2(Mg.Mn)o( Al, Fe)o(Si04)3, that of ordinary biotite being— (H,K)2(Mg, Fe)2( Al, Fe)2(Si04)3. The analyses given by Dana show 5°41 to 21:40% MnO. In colour the mineral is bronze to copper-red, with a pale red streak. In thin scales rose-red. The pleochroism is :— | ¢(b, c) = colourless or pale yellowish red, Le (a) = deep reddish brewn. 1 Catel. Govt. Central Mus., Madras, p. 3, (1855). 2 «The Madura Country ’, pp. 15, 27, (1868). 194 MANGANESE DEPOSITS OF INDIA : MINERALOGY, [ Parr: Some varieties show a maximum absorption for rays with vibrations at right angles to c, unlike other micas; but in those containing most manganese the absorption is normal, the pleochroism then being :— wt = red-brown, band c = dark brown. Certain intermediate kinds show no pleochroism. The optic axial angle of this mica is not given, but is probably small or nil ; for biotite is usually practically uniaxial, although the optic axial angle may occasionally be as high as 50°. Caswellite is the name given to an altered mica of a light copper-red colour and a bronze-like lustre resembling clintonite (seybertite), The structure is micaceous, the lamine being inelastic. G.=3°54, The mineral is not pleochroic and on analysis was found to be a silicate, chiefly of manganese and calcium, with smaller amounts of aluminium, iron, and magnesium. The one analysis published shows 15°95% of Mn,;03. It occurs with rhodonite, polyadelphite, and biotite, from which it is believed to have been derived, at the Trotter Mine, Frank- lin Furnace, New Jersey, United States of America, ! Alurgite :—This is a name given to a mica found at the manganese mines at St. Marcel, Piedmont. It has been investigated in some detail by 8. L. Penfield,? who finds that it is to be regarded as a distinct species of the formula HR»(AIOH)AI(Si03)4 with R=MgOH, K. It is most closely related to SDI The rehie of manganese in the mineral is small, namely 0°879% MnO and 0-18% MnO in the specimen analysed by Penfield. The mene is monoclinic ne the usual basal cleavage, whilst the lamine are flexible. H=3. G=2°83 to 2°85. In colour it is a deep brownish copper-red, whilst ‘cleavage pieces have something of the colour of clear chips of almandine garnet’. The streak is rose-red to pale pink. The pleochroism is not very marked owing to the fact that the absorption is nearly the same in all directions. The pieochroism is :— a and ¢ == red with a purplish cast. = brownish red. The optic axial angle, 2E=56° to 57°. Owing to twinning, however, the mineral is sometimes found to give a uniaxial figure. Manganchlorite is a manganiferous variety of the chlorite known as clinochlore, the formula of this mineral being HgMgs5AloSig0j¢ ; in manganchlarite there is 32°3% ak Ma replacing a by of the MgO. : Dana, Appendix I,p 2 Amer. Jour. Sci., Rivt. pp. 288 to 291, (1893). Cuap. VII. ] MANGANESE-MICAS AND CHLORITES. 195 The mineral is found at the Harstig mine near Pajsberg, Sweden, in association with manganophyllite; which it resembles, but from which it is distinguished by a lighter reddish colour. The double refraction and pleochroism are weak, whilst the mineral is distinctly biaxial. Cer- tain characters point to the possibility of this chlorite being triclinic, Indian Manganese-micas and Chlorites. Associated with the Indian manganese-ore deposits of the gondite series there is a considerable variety of micaceous minerals ; these are in most cases true micas, but occasionally may be either chlorites or altered micas. Although micas are comparatively common in some of these deposits, it is usually in the deposits of somewhat exceptional character, such as those where micaceous schists have been developed. The mineral is very rare in the true gonditic rocks. From these mica- ceous minerals we can first separate the variety that may be either man- ganchlorite or an altered mica. This mineral is found only in the Central Provinces, usually intimately associated with the manganese-ores; it has not yet been found in the rocks of the gondite series associated with the ores, The localities for this mineral are the following :— Balaghat district :—Ramrama. Bhandara district :—Kosumbah, Sukli, Chhindwara district :—Kachi Dhana, Sitapar, Manganchlorite. The mineral occurs in small books in the midst of the manganese-ore and almost always seems to be suffering alteration with the production of manganese-ore, probably by replacement. In colour it is bronze- to copper-coloured, and gives a bronze-coloured streak. A flake of the Kachi Dhana mineral was found under the microscope to give a biaxial interference figures, to be rich deep brown in colour, and to contain star-like inclusions, probably indicating the development of some secondary manganese-ore. The flakes were flexible but not elastic. A flake, examined to see that it was free from these inclusions, was found on fusion with the usual fluxes to give a distinct reaction for manganese. At Sitapar the mineral occurs in a rock containing four manganese-ores and an arsenate, as noticed on page 786. Some of the plates of the micaceous mineral from this locality are a greasy brown in appearance, whilst others are of a bronzy, almost copper, brown. The optic axial angle was found to be exactly the same as that of a flake of muscovite of which the optic axial angle was known to be 70°, A I 0 2 196 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ PartI: basal section showed the following pleochroism, assuming the two axes lying in this plane to be b and ¢:— ¢ = greenish brown to pale brownish green or sage-green, b = red-brown to raw sienna, I have called this mineral manganchlorite ? because the flakes or lamine are not elastic. The pleochroism shows that this cannot be the same as the Swedish manganchlorite and it may be that it is really an altered mica; but in this case it could not be regarded as manganophyllite, which it resembles in its colour, because of its high optic axial angle. If an altered mica, it cannot be caswellite, both on account of its pleochroism and because it looks very different to a speci- men of caswellite in the Geological Survey collection. Hence if a mica it must be a new variety. Provisionally, therefore, I shall call it man- ganchlorite?, and will so refer to it whenever I have occasion to mention this mineral in the descriptive part of this Memoir. This will thus serve to distinguish the mineral from all the other micaceous minerals found in the manganese-ore deposits; for these are all true micas, as is shown by the elasticity of their flakes. Brown Micas (Manganophyllite ?». Micas showing some tint of rich brown, bronze, or deep orange, are fairly often found in the micaceous schists, of which a list is given on page 333, associated with the rocks of the gondite series. The following is a list of the places at which such micas have been found :— Bombay :—Jothvad. Central India :—Kajlidongri. Central Provinces— Bhandara district :—Sitapathtr. Nagpur district :—Ghogara, Junawani, Kacharwahi, Pali, Ramdongri, Satak. Some of these micas are uniaxial and some of them biaxial, some- times strongly so. It is possible that some of them may be manga- nophyllite, but it is almost certain that there are two or more species amongst them, [ will notice three of the occurrences only. Jothvdd :—Many of the rocks I collected at this place contain brown micas. Although some of these are uniaxial and some biaxial, there does not seem to be asufficient difference between their tints to enable one to tell without obtaining an interference figure which micas are uni- axial and which biaxial. ‘T'he pleochroism is :— a = orange, pinkish yellow, and orange-pink, b and ¢ = deep orange, reddish orange, and red-brown, Cuap. VII. ] ALURGITE. 197 Sitapathir :—The dark brown mica associated with the crimson mica mentioned on page 198 is uniaxial and has the following pleochroism :— 2 = pale straw, b and ¢ = rich orange-brown. In thick sections there is seen to be a difference between the b and £ axis colours. They may then be described as :— b = orange-red, ¢ = mahogany-brown. Flakes of this mineral give a distinct reaction for manganese on fusion with the usual reagents. Junawani :—The mica, which occurs along the cleavage planes of the manganhedenbergite noticed on page 131, is bronze to copper- coloured and under the microscope shows the following pleochroism :— 3% = mahogany-red to brownish pink, dand c= warm light brown, often with an orange tinge. The absorption is ¢ slightly greater than b. The optic axial angle is large. Alurgite(?). Under this name we can group provisionally the various crimson and pink micas found in association with various of the manganese-ore deposits of India. In comparison with the micas of some tinge of brown or bronze the rose and crimson micas are rare. I have found them at four localities only :— 1. Kajlidongri, Jhabua State, Central India. 2. Sitapathur, Bhandara district, Central Provinces. 3. Ghogara, Nagpur district, Central Provinces. 4. Kacharwahi, Nagpur district, Central Provinces. These micas are found in the following rocks :— 1. Kajlidongri :—Here the mica occurs as a deep crimson mineral in complex rocks associated with the winchite-bearing rocks, these rocks containing winchite, blanfordite,. braunite, apatite, felspar, quartz, ealcite. The rock is often much altered and the micas consequently seem to have to a large extent lost their elasticity and under the microscope are seen to be altered and to be made up of alternating lamine showing different schemes of pleochroism. The one showing rose and ame- thystine tints is the predominant one ; it is not known whether the lamin showing orange tints are original or the result of the alteration of certain lamine of the crimson mineral. That it is more probably original is shown by the fact that a similar mica as far as pleochroism goes is also found at Jothvad, in this case apparently in a fresh 198 MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ Parr I: condition. Owing to the interlamination of these two micas the determination of their pleochroism schemes is a matter of difficulty. 2. The S ttapathir mica occurs in a rock composed of this and a bronze mica (page 197) with quartz, the whole rock as far as could be judged from the outcrop forming one wall of the manganese-ore deposit at this place. 3. At Ghogara the mica occurs in some thin cracks = to + inch wide traversing the nodules of manganese-ore that are found in the crystal- line limestone at this place. The colour of the mica is light crimson. 4. At Kdeharwahi there are numerous layers of micaceous schist interbanded with the layers of manganese-ores and other manganifer- ous rocks forming the manganese-ore deposit. These micas vary in tint from specimen to specimen, some being pink, some brown and others of intermediate colour. When they are examined it may be that some of them will be found to belong to alurgite. The pleochroism schemes of these micas and their optic axial angles as determined by means an eye-piece micrometer and comparison with a flake of muscovite of known angle, are shown in the following table :— TaBLE 18, Optical properties of pink micas. | Calas Pleochroism. Locaiity. | hand-speci- Optigaxal) q angle. | men. 2 | x b c ioe Oxannerilegeete an 1. Kajlidon- Crimson ts | Amethystine. | Brownish pink Deep rose. gri. | to light rose. | Orange layers : | Greenish yellow. Pale green. Orange-red to deep orange. | _ Light pinkish Rose. 2. Sitapathur Rose red 47°—60° | Pinkish lilac; orange. 3. Ghogara —§ Rose-red or | 59°—65° Lilac | Yellowish pink Light rose to light crim- | | lilae-rose. | som, 4. Kachar- = . = | | wahi. 5. Jothvad . ae Se Pink , Pale green Orange. ® St. Marcel Deep brown-| 56°—57” | Red witha pur-- Brownish red | Red with a pur- Piedmont ish Copper | plish cast. | plish cast. (Alurgite). red. Cuap VIL. | OTTRELITE. 199 On comparing the pleochroism of these Indian rose and crimson micas with that of the alurgite from St. Marcel in Piedmont, it will be seen that although the pleochroism schemes are somewhat different, the colours corresponding to each elasticity axis have a general resem- blance to one another. Thus the brownish tint in the red of the b axis of the typical alurgite corresponds to the yellowish, brownish, and orange, tints in the otherwise pink colour corresponding to the b axis of the Indian micas. It will also be noticed that the optic axial angles of the Indian micas bear a general resemblance to those of the St. Marcel mineral, especially in the case of the mica from Sitapathur. Hence these Indian micas can be provisionally regarded as alurgite, until they have been subjected to the test of analysis. The mineral from Jothvad of which the pleochroism is given 1s not one of the crimson micas, but is a rich brown. Its pleochroism, however, corresponds closely, except in the x axis, with that of the orange laminz in the crimson mica of Kajlidongri. Ottrelite. - This mineral belongs to the clintonite group of the mica division of the hydrous silicates. Its formula is doubtfully given as H,(Fe, Mn)Al,Sig09, and the analyses given by Dana show 0:93 to 896% of MnO. For the purposes of microscopic work, however, chioritoid and its varieties are also grouped under ottrelite in Rosenbusch—Idding’s * Microscopical Physiography ’, 4th edition, p. 289, (1905), and the formula H,(Fe,Mg,Mn)Al,Si0O7 given for the whole group of minerals, All ottrelites contain manganese and only some clintonites, but as it is often possible to distinguish the minerals only by chemical analysis, Rosenbusch-Idding’s practice will be adopted here, with the understand- ing that ottrelite proper contains manganese. It is characteristically found in phyllites and schists that have been formed by the metamor- phism of argillaceous sediments, though it is not a common mineral. I am not aware if any of my colleagues have met with this mineral in their studies of Indian rocks. I have myself found that it is not uncom- mon in the phyllites and mica-schists forming parts of the Chilpi Ghat series in the Central Provinces, and in their more metamorphosed equivalents, the mica-schists, usually mapped as a part of the meta- morphic and crystalline complex. These Chilpis, as is explained elsewhere in this Memoir (page 282), are the equivalents of the Dharwar of Southern India and the Ardvallis of Rajputana; hence future 200 MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ Part I: microscopic research on these latter rocks may lead to the discovery of ottrelite in them also. Accepting the definition according to which the mineral always contains manganese it is evident that the sediments from which the phyllite or schist was formed must have con- tained this element in appreciable proportion. The localities at which I have found ottrelite are (1) in mica-schists at the boundary of the villages of Sitasdongi and Chikhla in the Bhanddra district, at the point mentioned on page 763, (2) in the phyllites and phylli- tic schists lying on the west of the Badlaghat-ore body, and (3) in the mica-schists overlying the manganese-ore body at Ukua, in the Balé- ghat district. It is not all the micaceous phyllites and schists at these localities, however, that contain ottrelite, and it is often very difficult to detect any external difference between two rocks one of which contains ottrelite, whilst the other does not. The characteristic rock found both at Sitasiongi and Baldghdét contains quartz, muscovite, tourmaline, rutile, and a black ore, probably ilmenite, in addition to the ottzelite. The curious intergrowth of the rutile and ilmenite is noticed on page 313. When visible in the hand-specimen the ottrelite is seen to be of a darkish green colour. The evidence on which I base the determination of this mineral as ottrelite is (1) the fact that it gives a distinct reaction for manganese when it is possible to isolate a piece for testing, and (2) its appearance under the microscope. In the first place in sections showing the basal cleavages the extinctions are often oblique, the value of this angle rising to as much as 18°. In the second place the birefringence is very low, whilst thirdly the pieochroism is that characteristic of ottrelite. The pleochroism schemes made out from slides of the Sitasdongi and the Balaghat rocks, respectively, are shown below :— Sitasdongi. Balaghat. a = olive-green, 2 = olive-green. b = plum-blue to indigo-blue. b = indigo-blue. £ = pale yellowish green, t = pale yellowish. ‘The scheme given for Sitasdongiis exactly that given in Rosenbusch- Iddings, 4th edition, p. 292. Occasionally twinning is seen in sections across the cleavage. CHAPTER VIII. MINERALOGY —continued. Titano-silicates, Niobates, Phosphates, and Tung- states. Greenovite—Tscheffkinite—Columbite—Manganapatite—Triplite—A manganesian phosphate—W olfram. Greenovite. Greenovite is a red variety of sphene or calcium titanosilicate (CaTiSiO;) found at St. Marcel in Piedmont. It owes its colour to a small percentage of manganese. In one spot on the small hill at Jothvad in Naérukot State, a small vein or apophysis from the surrounding granite traverses the manganiferous banded rocks forming the main mass of the hill. This vein is composed of pink felspar (microcline and oligoclase with a little orthoclase), with a certam amount of interstitial quartz, and a large number of prisms and granules of dark-coloured minerals. The granules and stumpy prisms consist of a manganese-garnet and blan- fordite, respectively. Besides these two minerals, however, there is a manganiferous variety of sphene. It occurs in small dark brown prisms up to nearly } inch long, which, when detached and placed on the stage of the microscope, are seen to be transparent and pleochroic in yellow-green and a pale warm brown, the two colours being of about equal strength. The crystals are elongated, simulating a prism, in which the apparently prismatic faces are really drawn-out pyramid faces, n (111), the crystal being several times as long as broad. At the ends they are terminated by faces that are probably ¢ (001), a (100) and m (110) these faces being all of small size compared with the n faces. The crystals are in fact very similar to that shown in figure 6, page 713 of Dana’s System of Mineralogy, 6th edition, with the exception that the x face is wanting and the n faces are very much elongated in the direction of the vertical axis. The mean value of the angle nn’ as measured on the reflecting goniometer over two edges of a crystal was found to be 43° 30’, whilst the value given by Dana is 43° 49’; the images were not very bright or distinct. In thin sections under the microscope the mineral is found to be biaxial, and to show the very high refractive index and 202 MANGANESE DEPOSITS OF INDIa : MINERALOGY. {Partie double refraction characteristic of sphene. The colour of the mineral is not, however, that of ordinary sphene, but more intense. Cross sec- tions of the mineral showing diamond shapes, of acute angles measuring 30° to 50°, give the following scheme of pleochroism :— Axis of greater elasticity yellow-green to greenish yellow, Axis of lesser elasticity = orange-red and brown-red to almost rose. If the mineral be sphene then these axes should be the b and the rc axes respectively. The tints for these two axe; in deep-coloured varieties of sphene are :— b = yellow, often greenish, t = red with a tinge of yellow, i.e., practically the same as given above. A test for manganese distinctly showed this element to be present, though only in small amount. Mr. Blyth, of the Geological Survey, carefully tested the mineral and proved the presence of titanium. The mineral is therefore a slightly manganesian variety of sphene, ?.e., greenovite, the mangan- esian nature of the mineral accounting for its striking pleochroism. Tscheffkinite. This is a mineral that was first found in India by Leschenault in 1817 or 1818. It was first analysed by Langier in 1825 and was for some time not given a definite name, but was called the ‘ minéral de Coromandel’ by Beudant in his ‘ Traité de Minéralogie’.! The name ‘ tschewkinite ’ was first given to the mineral in 1842 by G. Rose 2 when the author investigated a specimen from the second locality for this mineral. namely the Ilmen Mountains in the Ural. The Indian mineral was later more accurately analysed by Damour .? For a long time the locality of this mineral in India was vaguely given as the coast of Coromandel. Mr. F. R. Mallet, however, in 1892,4 in a paper entitled ‘Note on the locality of Indian Tscheffkinite’, showed that the exact locality is probably Kanjamalai hill, 5 miles W.-S.-W. of Salem, Madras Presidency. Tscheffkinite is a mineral of very complex composition, and, owing to the fact that the mineral analysed seems to be in all cases an alteration product, the true formula of the mineral is not known. It is classed 1 Vol. II, p. 652, (1832) [Dana]. 2 ‘Reise nach den Ural......’, II, (1842) [Dana]. 3 Bull. Soc. Geol. de France, 2nd Ser., XIX, p. 550, (1862). 4 Rec. Geol. Surv. Ind., XXV, pp. 123-127, (1892). Cuap. VIII. } COLUMBITE. 203 by Dana amongst the titanosilicates. The composition of the Indian mineral as analysed by Damour is shown below :— Si02 : y d : , ‘ , eres TiO2g 4 : ; . : s . 20°86 Ce203 38°38 AlgO3 1°72 FeO 7°96 MnO 0°38 MgO 0°27 CaO é : f i : 2 » , 4540 H20 and volatile matter . i . : 1°30 Langier’s analysis showed 1:20% of oxide of manganese, probably Mn304. The specimens from the Urals show 0°75 to 0°83% MnO. According to Des Cloiseaux,! the Indian ‘matiére n est pas parfaitement homogéne, car j'ai reconnu au microscope qu ells >e compose d’une masse brune sans aucune action sur la lumiére polarisée, dane laquelle sont enchassés de trés-petits grains incolores fortement biréfringents’. The characters of the Indian mineral are as follows :—H.=5°5—6. G.=426. Lustre vitreous, inclining to resinous; colour brownish black, translucent. “Tschewkenite’ is also recorded as having been found by the Rev. C. F. Muzzy ? near Dindigul, * forming a constituent part of - por- phyritic granite’. But the mineral has never been found since, and it is doubtful if the identification was correct. Columbite. Columbite and tantalite are two related minerals, the former being theoretically a niobate or columbate of iron and manganese and the latter a tantalate of the same two metals, the theoretical formule being (Fe,Mn)Nb 20g and (Fe,Mn)Tag0,, respectively. In Nature minerals corresponding to the foregoing formule are very rarely found, there being every gradation from columbite to tantalite by the replacement of niobium by tantalum, so that the more general formula is (Fe,Mn) (Nb,Ta) 20g. With an increase in the amount of tantalum and a corre- sponding decrease in the amount of niobium in the mineral there is a continuous increase in the specific gravity, so that by determining this constant it is possible to decide whether to call a particular specimen * Manuel de Mineralogie ’, I, p. 554, (1862). ‘atal. Govt. Central Museum, Madras ; * Madura, its rocks and minerals’, p. 9, J. H. Nelson. ‘The Madura Country ’, p. 15, (1868). 204 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ ParTI: columbite or tantalite. When the amount of manganese present is very high the mineral is known as mangano-columbite, or mangano- tantalite, according to its composition. The amount of manganese protoxide, MnO, shown in the analyses quoted by Dana varies from 0°81 to 13°88%. No analyses have yet been made of Indian specimens. The specific gravity ranges from 5°3 to 73. H.=6. The colour is usually iron-black with a sub-metallic to sub-resinous lustre. This mineral has been found at four localities in India, two of them in the Monghyr and Hazaribagh district, Bengal, one in the Nellore district, and one in Mysore State. Probably in all cases, the mineral occurs in mica-bearing pegmatites. It was first found at the Dattu Mines, Pananoa Hill, near Nawadih, East Indian Railway, Monghyr district, by Mr. H. H. French,! the specimens sent being identified by Dr. T. H. Holland. The occurrence of the mineral was then examined by Dr. Holland who found that it occurs ‘in lumps imbedded in the quartz of a very coarse grained pegmatite dyke, intruded into a mica schist, which is crowded with tourmaline crystals.’2 The mineral was next found by the late Mr. A. M. Gow Smith in the Government forest of Koderma in the Hazaribagh district, Bengal.? The specimens from this locality were found to have a considerably higher specific gravity than those from Nawadih, namely 6°19, as against 5°54. The third find was by Dr. T. L. Walker in the mica-bearing pegmatite of Chaganam, Nellore district, Madras, the specific gravity of the mineral being 5°75.4 The mineral has also been found by B. Jayaram who writes 5— « About 100 yards from the tank bund and 33 furlongs north of Masti occurs a vein of pegmatite traversing the hornblende granitoid gneiss. It is singularly rich in a dark mineral probably columbite,...... This black mineral has been observed in a few places altering into biotite’. Masti is in the Bangalore district, Mysore. Judging from the specific gravities given above the mineral from each of the three first localities contains more Nb:O; than Ta,05, and is therefore to be called columbite rather than tantalite. The value _ of columbite and tantalite depends rather on the percentage of tanta- lum than on that of the niobium present. Judging from the specific gravity 1 Rec. Geol. Surv. Ind., X XVII, p. 1 at end of volume, (1894). a 2 Rec. Geol. Surv. Ind., XXVIII, p. 10, (1895). 3 Rec. Geol. Surv. Ird., XXX, p. 129, (1897). » 4 General Report of the Geological Survey of India for 1898-99, p. 9; ibed., 1899-1900, » 9. 5 Ree. Mysore Geol. Dept., III, p. 182, (1900-01). Cuap. VIII. ] MANGANAPATITE. 205 of the Koderma specimens the mineral from this locality must contain a considerable amount of Tag0s. The Reverend Mr. Muzzy reports the find in the Madura district of a mineral resembling ferro-tantalite, this being an old name for tantalite.! In Nelson’s ‘Madura Manual’, p. 16, (1868), the ferro- tantalite is stated to occur near Palani, doubtless the same place as Palni, about 69 miles N.-W. of Madura, in porphyritic granite, this informa- tion being based on the notes and specimens of Muzzy. Manganapatite. Apatite is a mineral belonging to the hexagonal system and having a composition corresponding to one of the two formule 3CagP 0g. CaCl, and 3CagP90g.Cal'g, according as it contains chlorine or fluorine, the two varieties being known by the names chlor-apatite and fluor-apatite, respectively. Sometimes a portion of the calcium is re- placed by manganese and the mineral is then known as manganapatite. The analyses given in Dana show 1°35 to 10°59%% of MnO in the exam- ples grouped as manganapatite. These manganapatites are all fluor- apatites. In colour they tend to be dark green or bluish green. One example, namely that from Branchville, Connecticut, containing 10°59% of MnO, has a higher specific gravity than is usual for apatite, namely 3°39, the ordinary value being 3°17—3'23. This is doubtless due to the high percentage of manganese protoxide, and probably a careful investi- gation of the specific gravities of manyanapatites would point to an increase of specific gravity with increasing percentage of MnO. On page 1063 reference will be found to a veinlet of apatite in spandite- rock at the Kodur mine, Vizagapatam district. This apatite, of which I have several specimens, is of a lavender colour, breaks with a con- choidal fracture, and has then a glassy appearance. Chemical examina- tion shows that the mineral is fluor-apatite, small pieces of which give a distinct reaction for manganese. As the mineral is very much cracked and these cracks usually contain thin black films of manganese oxide, some difficulty was experienced in picking out pure pieces for this test. The mineral is cavernous and then sometimes shows signs of the faces of the hexagonal prism. In these cavities the apatite is always coated with a thin skin of a white enamel-lke substance having a nacreous lustre. A small piece of the apatite was found to have a specific gravity of 3°22. Under the microscope the mineral often shows numerous x E. Balfour, Catal, Govt. Cent. Museum, Madras ; ‘Madura, its rocks and minerals ’, p iv, (1855), 206 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ PartI: opaque white bands parallel to the vertical axis ¢, so that at first sight the mineral looks like a felspar with lamellar twinning. The apatite with these bands shows a satiny lustre on the fracture surfaces. The mineral is also traversed by fairly numerous cleavages parallel to the basal plane. On page 1073 is mentioned the find at Devada, also in the Vizagapatam district, of a large quantity of green apatite in corroded hexagonal prisms up to five inches in diameter. Some of the crystals show pyramidal terminations. A carefully selected chip of the mineral gives a weak reaction of manganese. The apatite is a fluor-apatite and theiefore can be designated at length as mangan-fluor-apotite. On a fresh frac- ture it shows a beautiful deep sea-green colour. Under the microscope in a small chip it exhibits a rich pleochroism, namely w = rich green and « = blue-green. Absorption ise > w. The specific gravity as determined in the Geological Survey Laboratory on a large number of carefully picked small chips is 3°16. From the place in which this mineral is said to have been found, it is probable that it came from a very coarsely crystallized variety of kodurite, in fact from a sort of kodurite-pegmatite. The Kodur mineral, which occurs as a veinlet in a spandite-rock, is to be regarded as the product of segregation from the mass of manganiferous rock during cooling. As therefore this apatite is probably an original mineral, and was moreover probably one of the first minerals to crystallize out, it is not surprising that it should have taken up a small quantity of manganese. Probably most of the apatite contained in the rocks of this series is more or less manganiferous, though in most cases the apatite is in too small grains for this supposition to be tested except at the expense of a considerable amount of time and trouble. Triplite. Triplite is a monoclinic orthophosphate of the formula (RF)RPO, or RgP90g.RF5, with R=Fe and Mn, and also Ca’ and Mg in subordinate amount. It is a heavy dark brown to black mineral of specific gravity 3°4-3°8, and hardness 4 to 5°5; and is found at several localities ii dif- ferent parts of the world. The amount of MnO present varies in the ana- lyses given by Dana from 14°86 to 54°14%. This mineral has been found in India in considerable masses in peg- matite near the mica mine, 2 miles 8.-E. of the village of Singar in the Cuap. VIII. ] A MANGANESIAN PHOSPHATE. ; 207 Gaya district, Bengal. Uraninite (pitchblende), uranium-ochre, and torbernite, are found at the same place as the triplite.! The mineral was first found by Kishen Singh of the Geological Survey and identified by Dr. T. H. Holland. The Indian specimens show various shades of dark brownish black, but are occasionally lighter brown. They have horny lustre. One mass is eleven inches long and weighs forty-one lbs., this including a verv small amount of attached quartz. A Manganesian Phosphate. At Branchville in Connecticut, U.S. A., is a vein of albitic granite containing a most remarkable series of manganesian phosphates :—dick- insonite, eosphorite, fairfieldite, fillowite, hureaulite, lithiophilite, natro- philite, reddingite, triphylite,? triplite, and triploidite. Considering the abundance of phosphorus in the form of apatite in the manganese- silicate-rocks of India, one would expect a careful search to lead sooner or later to the discovery of a similar series of manganiferous phos- phates. Apatite, and consequently phosphorus, is most abundant in the rocks of the kodurite series of Vizagapatam ; but up to the present, with the exception of manganapatite, no manganesian phosphates have been found in these rocks. In the rocks of the gondite series at Jothvad in Narukot, Bombay, apatite is also very abundant ; but it is unaccompanied by any other phosphates, as far as has been at present ascertained, although there are minerals at this deposit that have not been at present identified aad of which no mention is made in this Memoir. In the rocks of the gondite series in Jhabua and the Central Provinces on the other hand, apatite is usually much scarcer, although sometimes found in abundance. At one locality, namely Chargéon in the Nagpur district. Central Provinces, a different phosphate is found. It occurs in a very beautiful rock composed of orange spessartite trapezohedra up to 4 to } inch in diameter, set in a martrix of rose-pink rhodonite in plates sometimes an inch in diameter. With the rhodonite is mixed a varying proportion of barytes and an _ oil-green mineral. In some places the latter mineral is present in some abundance. It occurs in irregular patches sometimes an inch in diameter. It just scratches apatite and so can be considered to have a hardness of 5 - 5:5. Its specific gravity as determined by means of Sonstadt’s solution is 1 T. H. Holland, Mem. Geol. Surv. Ind., XXXIV, pp. 32, 51, (1902). 2 See a series of papers by O. J. Brush and E. S. Dana in the Amer. Jour. Sci., Vols. 16-18, 39, years 1878-1879, and 1890. 208 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Pagrt: 3°404 to 3°409, or, say, 3°40 to 3°41. It fuses rather easily to a dark- brown mass, and is ‘found by qualitative analysis to be a phosphate of manganese, magnesium, and sodium, with a little calcium, and possibly a little iron. Water is doubtfully present. The mimeral is uniaxial and slightly dichroic. The uniaxial character of the mineral was determined by means of an interference figure obtaimed in a chance section. If true it is a most important character, because none of the manganesian phosphates are uniaxial except manganapatite, which is quite different to this mineral in most respects. .Hence there seems to be no alternative to regarding this mineral as a new species. In case the determination of the uniaxial character of the mineral be at fault it is as well to see what minerals this phosphate is otherwise most closely related to. In specific gravity and hardness it agrees with natrophilite, an orthorhombic mineral of the formula NaMnPO,. But it differs from the latter in containing magnesium in addition to the other constituents, and in being green in colour instead of wine-yellow, the colour given for natrophilite. It agrees with dickinsonite in colour, and fairly closely in specific gravity. It is, however, harder, and is practically free from iron, containing magnes- ium instead, These are the only phosphates to which the mineral seems to have any resemblance. Hence even if the two determination of the uniaxial character of the mineral be at fault it must still be regarded as a new mineral. I do not, however, propose to name it until its characters and chemical composition have been more fully ascertained. Wolfram. Wolfram or wolframite is a heavy dark brownish to black mineral of monoclinic crystallization. H.=5 to 5:5. G@.=7:2 to 75, The streak is usually some shade of dark reddish brown to black. Perhaps one of the most characteristic features of this mineral is the perfect cleavage parallel to the plane 6b, so that the mineral looks as if it were laminated. In composition it is a tungstate of iron and manganese. When the latter is present to the exclusion of iron the mineral is called hiibnerite. Characters. In India wolfram has been found in the Hazaribégh district, Bengal, |! and in several places in Burma. In the latter area placer deposits of tinstone are to be found in many of the streams and rivers draining down from Occurrence in India. 1 Rec. Geol. Surv. Ind,, XXI, p. 21 (at end of volume ), (1888). Cuap. VIII. ] WOLFRAM. 209 the range of granite hills and mountains that separates Lower Burma from Siam, and stretches north from the Pakchan river bounding the Mergui district on the south, through the whole Tenasserim divi- sion, to a point at least as far north as Karenni in the Southern Shan States. Many of these placer deposits have been stated at different times to contain wolfram. A complete account of these occurrences cannot be given here, but will be given later in the article on tungsten in the ‘ Mineral Resources of India’, when this is published. It is sufficient to say here that wolfram has been recorded from Karenni, and the districts of Amherst, Mergui, and Tavoy, but never in situ. This present year (1907), however, Mr. J. J. A. Page of the Geological Survey has found wolfram in sitw in the parent rock. The locality is in a 15-foot wide reef on North Hill near Maliwun; of two specimens brought from here by Mr. Page, one shows the wolfram in a quartz matrix without any other minerals, and the other consists of quartz containing wolfram, cassiterite, and a little copper pyrites, the wolfram being in allotriomorphic crystals up to 1 inch long. The other locality is 6 miles south of Inner Bokpyin in the same district, the rock in which the welfram occurs being that known locally as ‘kra ’, which is a decomposed tour- maline-granite containing tinstone. In this case Mr, Page detected the mineral only after panning the rock for tinstone, the wolfram not being visible in the hand-specimen. A specimen recently received from Mr. Kellerschon was found, on being tested by Mr. G. G. Narke of Nagpur in the Geological Survey laboratory, to be wolfram. One piece is three inches long. In Decem- ber 1907, I was able to visit the locality of the find—Agargdon in the Nagpur district— ; the mineral occurs in quartz veins interbedded witb mica-schists, and with associated tourmaline-schist.! Ree. Geol. Surv. Ind., XXXVI, part 4, (1908), me CHAPTER IX. MINERALOGY —continued. Associated Non-Manganiferous minerals, Graphite—Chaleopyrite—Pyrite—Pyrrhotite—Halite—Rose quartz—Amethyst— Chalcedony and chert—Opal—Iron-ores—Hematite—Limonite—Magnetite—Martite —Gibbsite—Microcline—Sapphirine—Lithomarge and kaolin—Arsenates——Distinc- tion of arsenates, apatite, and barytes—Barytes. On pages 35, and 323—5 are lists of the minerals associated with the manganese-ore deposits of India. A large number are not of sufficient interest to require any notice beyond that necessary in connection with the rocks in which they occur. A few, however, of which a list is given on page 35, are of more interest, usually on account of being found in crys- tals or masses of size sufficient to be examined without the use of the microscope. About these I propose to give here a few notes. _ Graphite has been found at only two localities in association with oe manganese-bearing rocks in India. Both these occur- iraphite. : : Sees : rences are in the Vizagapatam district. One was in one of the manganese-pyroxenites found at Chintelavalsa, the graphite being present in scales up to # inch across, associated with the quartz, in a rock composed of spandite, quartz, green pyroxene, rhodonite, and graphite, with also small quantities of biotite, apatite, and sphene. The other occurrence was as a loose block in the valley to the south of Taduru on the way to the Tdduru occurrence of manganese-pyroxenite. The rock was a soft decomposed rock found under the microscope to be composed of garnet (spandite), apatite, and manganese-ore, with abundance of the graphite, very conspicuous in the hand-specimen. Graphite was also seen in small quantity in the rock from Taduru noticed below in connection with pyrrhotite. The occurrence of graphite in these manganese-silicate-rocks may be an original feature, cP the graphite may have been picked up from the associated rocks of the khondalite series, in which graphite is one of the most characteristic minerals. The manganese-silicate-rocks of India and the associated ores are remarkably free from all sulphides. Nevertheless, in one of the gneisses interbanded with the manganese- bearing rocks of Jothvad in Ndarukot there is a little chalcopyrite, I pP2 Chiicopy rite. 212 MANGANESE DEPOSITS OF INDIA: MINERALOGY, [ Part I: the containing rock being an epidote-hornblende-quartz-rock with sphene, apatite, tourmaline, and wollastonite. One occurrence of pyrite has been observed, namely in a_hornstone-like chert vein at Kodegéon in the Nagpur district (see page 847). In one case, moreover, J have noticed what may be pyrrhotite. This was in a rock obtained as a loose block below the manganese-pyroxenite outcrop at Taduru in the Vizagapatam district The rock is composed of apatite, spandite, rhodonite, and quartz, with a little graphite and sphene. Under the microscope by reflected light a few scattered granules are to be seen of a opaque metallic bronzy mineral, which may be pyrrhotite. Pyrite. Pyrrhotite. A case has been noticed of a fine white felt of sodium chloride or halite found as a coating on joint planes of the Halite. ; ; : : , manganese-ore at the Kandri mine in the Nagpur district.! A mineral that is not infrequently found in association with man- ganese-ore deposits in India is the rose-coloured variety of quartz. I have already noted two occur- rences in the Chhindwara district, namely at Khairi and Dudhara.2 Other occurrences of this variety of quartz are as a vein in the decomposed lithomargic rocks at Kodur in the Vizagapatam district (see page 1062), and as large loose hexagonal crystals, of amethystine-rose colour, in the detritus or gravel deposits being sorted over for their loose fragments of manganese-ore at Sandanandapuram in the same district (see page 1075). The quartz associated with a piece of apatite- gondite at Guguldoho in the Nagpur district also exhibited a pale yet decided amethystine tint. Rose or amethystine-rose quartz is doubtless often found under circumstances when there are no strongly manganifer- ous rocks near by, but all the same one cannot avoid suspecting that the colouration may be connected with the possible presence of manganese in the quartz. Dana in his System of Mineralogy, page 187, puts forward this suggestion, whilst he also mentions that Fuchs found | to 15% of titanium in rose quartz from Rabenstein near Bodenmais, and attributed the colour to this constituent. Rose quartz. Some three years ago I made an examination of the Khairi rose quartz in conjunction with Mr. T. R. Blyth. We found that the quartz contained a very small quantity of manganese ; this could be extracted by boiling the very finely powered mineral with dilute sulphuric acid 1 Rec. Geol. Suv. Ind., XXXI, p. 237, (1904). 2 Ree. Geol. Surv. Ind., XXXII, p, 176, (1906). Cuap. [X.] ASSOCIATED NON-MANGANIFEROUS MINERALS. 213 and its presence proved by means of the red lead and nitric acid test. No attempt was made to estimate the quantity of manganese present, or to find out the form in which it existed. Under the microscope I found that the quartz contained a large number of minute liquid inclusions similar to those so often found in this mineral. In view of the fact that the manganese could be extracted by boiling with acid and did not require a fusion to release it, it seems probable that the manganese is present in these cavities as a salt in solution and that it only needs sufficiently fine grinding for it to be possible to extract the manganese salts in solution. Probably if water had been used instead of acid the result would have been just the same.! The colour of amethyst has also been supposed to be due to manga- nese (Dana, page 187), and recently the results of some experiments by M. Berthelot? have been published showing that this is correct and that the colour can be removed by heating the mineral. It is supposed that tne colouring matter is present aS a manganic compound and that heating decomposes this into a manganous compound with the liberation of oxygen. It is further stated that the colour can be causea to return by submitting the mineral to the influence of radium. No true amethyst has been found in association with the manganese-ore deposits of India, the nearest approach being the amethystine-rose quartz of Sandanandapuram and the pale amethystine quartz of Guguldoho. In the geodes of the Deccan Trap formation, however, amethyst is not an uncommon mineral; but the colouring is often uneven, the erystals being patchy or zoned. As a locality may be mentioned the railway cuttings on the Shikara Ghats in the Seoni district, Central Provinces, where I obtained a strongly coloured geode. It does not follow, however, that any more are to be readily found at the same place; for the distribution of geodes and the nature of their mineral contents seem to be most capricious throughout the Deccan Trap formation. Amethyst. In the manganese-silicate-rocks of both the kodurite and gondite series quartz is commonly found as an original mineral. As the result of the chemical changes that have taken place in these rocks, however, there has often Chalcedony and chert. 1 Mr. Blyth has since tried to extract the manganese by using water instead of sulphuric acid : but did not succeed in doing so. 2 Comptes Rendus, CXLIII, pp. 477-488, (1906) ; abstract in Jour. Chem. Soc., XC, Part II, p. 863, (1906). E 214 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [Part I: been a considerable production of secondary silica; this does not form as quartz, but as either opal or chalcedony ; the latter is often impure and coloured by the presence of small amounts of manganese or iron oxides and is then best designated chert. Chert is found in large quantities in the manganese mines of the Vizagapatam district, its colour being as a rule of some shade of brown. Such brown chert is also found in the manganese-ore deposits of the Central Provinces, but not very commonly, and then only in small quantities. In association with the manganese-ore deposits that occur in the crystal- line limestones in the Chhindwara and Nagpur districts there is, however, often a considerable quantity of black chert, owing its colour to the presence of manganese oxides, and formed by the replacement of the limestones by silica. Opal is also not infrequently formed in the manganese-ore deposits. Thus it is common in the Vizagapatam mines, as a replacing material for the telspathic portion of kodurite, the product frequently taking the form of manganese-garnet set in a matrix of opal. Good examples of this are seen at Kotakarra (page 1097), Kodur, and at Boirdni in Ganjam (page 1034) ; see also Plate 8, figures 1 and 2, In the Nagpur district opal is sometimes found filling cracks in the manganese-ores and associated rocks. Good examples are mentioned under Kodegéon (page 847) and Kandri (page 873). Opal is also sometimes found in the Chhindwi za deposits. Opal. One of the most extraordinary features of the manganese-ore deposits of the gondite series, is the freedom of the manga- nese-ores from admixture with iron-ores. When it is considered that these deposits are supposed to have been formed either immediately or ultimately by the metamorphism of manga- niferous sediments, this rarity of iron-ores is all the more surpris- ing; for it means that when the manganiferous sediments were deposited the mineralized waters from which they may be supposed to have been formed contained large quantities of manganese salts and only a comparatively small quantity of iron salts. It might be argued that these waters really contained considerable amounts of iron salts as well and that the portions that were not deposited with the manganese oxides (for it must be remembered that nearly all the manganese-ores contain a certain amount of iron) were deposited in other parts of the same area where the conditions were slightly different. Were this the case depnsits of iron-ores should be found at the same horizon as the manganese-ore deposits, 7.c., on the continuation of their strike. Tron-ores. Cuap. IX.] ASSOCIATED NON-MANGANIFEROUS MINERALS. 215 Except in the case of the Balaghdt deposit, where the band of manganese- ore in tailing out gives place to limonite, this has not been observed. Consequently such occurrences of iron-ores as have been noticed in association with the manganese-ore deposits are of particular interest. The occurrences to be noticed in association with the deposits of the gondite series in the Central Provinces are at Mansar, Mansar Exter- sion, Mandvi Bir and Junapani (pages 885, 892, 970, 976, respectively). In all these cases the ore is red hematite, sometimes massive, and sometimes in the form of aggregated small scales of specular hematite. Another occurrence in this series is at Kajlidongri in Jhabua, where there is a vein composed of quartz and hematite traversing the deposit (page 687). The hematite is in micaceous plates up to 2 inches across. But this occurrence, being of vein origin, is not to be regarded as similar to those in the Nagpur district ; the latter may be the product of the consolidation and metamcr- phism of original sediments, although it is perhaps as probable that in at least some cases the hematite is only a secondary introduction. In the manganese mines of the Vizagapatam district no definite deposits of iron-ores are found, but small quantities of yellow ochres are often found mixed with the manganese-ores and are also found in irregular patches in the lithomargic ‘ country’. In the deposits formed by secondary processes on the out- erops of the Dharwar rocks, as in Singhbhum, Jabalpur, Sandur, and Mysore, the manganese-ores are commonly associated with iron-ores, usual- ly limonite ; in the lateritic deposits also the manganese-ores are almost invariably intimately associated with iron-ores, both hematite and limonite. Another ore of iron that is sometimes found in association with the manganese-ore deposits of the gondite series is magnetite. Two occurrences of rocks of these series containing magnetite have been found. One of these is at Kedegaon in the Nagpur district where the mineral occurs in a rock composed of magnetite, spessartite, and quartz; the rock is therefore to be called magnetite-gondite. The other is at Kachi Dhana in the Chhindwara dis- trict and is a rock composed of magnetite set in a matrix of chalcedony. It is possibly a silicified magnetite-spessartite-rock.!_ Magnetite also occurs as a magnetite-quartz-rock associated with the manganese-ore deposits at 1 It has not been proved that these magnetites are non-manganiferous, Consid- ering their association they may be manganmagnetites, But the individual grairs of the magnetite are s0 small and so intimately associated with the other minerals that it would be a matter of extreme difficulty to determine this point, Hematite. Limonite. Magnetite. 216 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: a few localities, e.g., at Ramdongri in the Nagpur district, on the neck joining hills 5 and 12. . Magnetite-quartz-rock is also found at Katangjheri { (Balaghat district) and at Sitapathir (Bhandara district), the occur- rence at the latter locality being in the form of magnetite in quartz resembling vein-quartz. In none of these cases is the magnetite-bearing rock found in any considerable quantity. In some of the Vizaga- patam manganese-ore deposits a very magnetic mineral is often found ; but in the few cases in which this has been tested it has been found to react slightly for manganese. Hence the mineral has been noticed under the heading of manganmagnetite. At Jamrapani, Balaghat district, there is a rock associated with the manganese-ore deposit in such a way as to suggest that it is an intrusive. It is composed of quartz, muscovite, and a black mineral, which has the outward shape of magnetite. Some of the crystals when tested give a black streak and are found to be magnetic; these can be regarded as magnetite. Others give a red streak and are less strongly magnetic; these are to be regarded as martite formed by the conversion, more or less complete, of magnetite into hematite. That the change has not been completed is shown by the magnetism that the mineral still retains. Other examples of martite have been found, as for example at Hatora, where there is a rock composed of magnetite, quartz, and some apatite and garnet, in which some of the magnetite seems to have been converted into martite, as evidenced by the streak. Martite. As I have already noticed,! the oxides of aluminium, iron, and manganese, behave in laterite in a manner exactly parallel with their behaviour in the laboratory. ‘Thus the oxides of aluminium and iron, which are precipitated in the same group in the ordinary qualitative separation, are often very intimately associated with one another in laterites, although they also in many cases separate or segregate from each other. With manganese, however, there seems to be a very strong tendency to segregate from the other oxides with the formation of definite manganese-ores, containing of course a certain amount of oxides of iron and aluminium, more of the iron than of the aluminium. These ores usually take the form of nodules, masses, and veinlets. They are almost always associated with the ferruginous laterites rather than with the aluminous laterites or bauxites. This is of course due to the greater chemical resemblance of manganese to iron than to aluminium. I have, however, noted one case in which an Gibbsite. 1 Ree, G, 8. I., XXXIV, p, 168, (1906). Cuap. IX.] ASSOCIATED NON-MANGANIFEROUS MINERAIS. 217 aluminous mineral occurs in close association with manganese-ores.! This is at Talevadi in the Belgaum district, where gibbsite, AlgO3.3H ,0O, is found as incrustations and infillings in cracks and cavities in the manganese-ore. The gibbsite must have been formed after the psilomelane, the aluminium oxide having been derived, in all probability, from another mass of the laterite close at hand. In several of the deposits of the gondite series of the Central Provinces there are intrusive veins, masses, and patches, of felspathic rocks of pegmatitic character, in which the felspar is usually microcline. In one case, namely at Satak II, the microcline was able to develop crystal faces owing to the presence of a vug-like cavity in the rock. The crystals range up to 1‘5em. in diameter and are of a dirty white colour. One of them that 1s especially well developed shows the basal plane, c (001); the prisms, m (110), and M (110); the brachy-pinacoid, 6 (010); the + hemi-macrodome, x (101), and a negative hemi-macrodome. Microcline. aed On page 757 I have noted the occurrence in a complex quartzite, 4 forming the ‘country’ of the Chikhla deposit at one part of its length, of a blue mineral that is to be doubtfully identified with sapphizine. As the result of the chemical alteration to which the rocks of the kodurite series in the Vizagapatam district have been subjected large masses of hydrated alumin- ous silicates have been formed. They are of various colours, white, yellow, pink, and lavender, and, when coloured, probably contain oxides of iron or manganese. The material can be designated by the term lithomarge, the name given to the firm, compact and apparently non- erystalline variety of kaolin, 2H :0.Al,03.2Si0O,. For it must be noted that although the lithomargic rocks, as seen in mass in the quarries, seem to be very soft and friable so that they give rise to con- siderable trouble in the quarrying operations, yet often a hand-specimen can be trimmed out of a piece of the material when it is dry. A piece of the white variety was analysed by Mr. J. C. Brown, of the Geological Survey of India, with the following result (1°18% of moisture having first been removed by heating at 100 °C.) :— Sapphirine. Lithomarge and kaolin. Combined water . : : ; 13-08 Silica . : ; A r : 49-84 Alumina : . ; , $ 36-96 Lime . ‘ A : : . traces 99-88 1 Rec. G. 8. I., XXXV, p, 169, (1906). 218 MANGANESE DEPOSITS OF INDIA‘: MINERALOGY. [ Part I: On grinding the sample for analysis it was found that a little free quartz was present. Consequently the analysis can be recalculated as follows :— Kaelin . : é : - - 93°42 Quartz . 0 4 ; : é 6-40 Surplus alumina. : : : 0-06 99-88 It is an interesting fact that many of the Indian manganese-ores when analysed are found to contain AsoO;, though usually in exceedingly small quantities. Thus the highest amount returned in the analyses carried out at the Imperial Institute is, with one exception, 0°022%, and in the analyses made by Messrs. J. & H. 8S. Pattinson, 0:047%. Nevertheless, it is an important point to determine the form in which this constituent is present in the ore. Arsenates. At two different localities | have found crystalline arsenates. One occurrence is at the Sitapar deposit in the Chhindwara district, where the arsenate occurs as & pale pinkish white to white mineral mixed up with the manganese-ores. It is usually interstitial with regard to the other minerals present, and is translucent, with a greasy lustre, a rather even fracture, and a white streak. H.—5 in fresh pieces, for the mineral tends to become opaque white and softer. It is brittle and easily crushed and is soluble in dilute acids. Qualitative examination of the mineral shows that it is essentially an arsenate and phosphate of calcium with small quantities of other constituents. As one specimen of the ore contained a piece of this mineral showing three sides of what looked like a hexagonal prism, it is possible that this mineral is isomorphous with apatite. This prismatic crystal shows thin white lines parallel to the basal plane, due perhaps to parting planes. Under the microscope the mineral is allotriomorphic with regard to the manganese-ores, shows a very high refractive index, and polarizes in greys of the first order. In one section two sets of cleavages at right angles were seen. These possibly corre- spond to basal and prismatic cleavages. Samples 10 and 10A, of which the analyses are given on page 787, of the ores of this deposit contained 0003 and 0°095 per cent, As )OQ5, respectively, the original sample having been divided into two, one free from visible arsenate and the other containing it. The Sitapar arsenate. Cuap. [X.] ASSOCIATED NON-MANGANIFEROUS MINERALS. 219 The other place at which arsenates occur is Kajlidongri in the Jhabua State, where two different minerals of this group The Boonen: #00: are found. One of these isin a vein of quartz and barytes, traversing the manganese-ore body at eross-cut 6 (see Plate i9). The arsenate occurs in sparsely distributed rounded crystals up to half an inch long. It is of a sage-green colour and looks exactly like apatite at first sight. That it is not apatite is indicated by its inferior hardness, between 3 and 4, instead of 5. Qualitative examination of the mineral showed it to be an arsenate of calcium and magnesium, with small quantities of other constituents. The other occurrence of arsenates at this locality is in the N. W. spur workings at the point shown on the plan of this deposit on Plate 19. Here the mineral was found in a rock of which it formed the chief constituent, the other minerals present being quartz, spessartite, and braunite. The relations of this rock to the manganese-ores with which it was associated were obscure and I could not determine if it were a vein rock or a proper member of the gondite series. As seen in a hand-specimen of the rock, the arsenate, On account of its cleavage, suggests a green felspar at first sight, the coarseness of the rock being about that of an ordinary granite. The hardness of the mineral is about 3. Its colour is a pale green. It dissolves easily in dilute hydrochloric acid on heating and gives reac- tions for water and arsenic inthe dry way. It was examined qualita- tively by Pandit T. 8. Kochak in the Geological Survey Laboratory, and was found to be an arsenate of magnesium with a very little lime and a certain amount of water. Under the microscope the mineral is colourless, shows a high refractive index, and polarizes in colours of she second to fourth orders in sections showing first order colours for quartz. The cleavages are well marked forming two sets crossing like those of calcite. The angle between these cleavages varied from 51° to 65° in those measured. Lamellar twinning is sometimes shown as well as simple twinning. In some cases the section was at right angles to one optic axis, thus showing that the mineral is optically biaxial. One of these brushes indicated, in a section in which the angle between the two set of cleavage was 60°, that the optic axial plane lies from an acute angle to acute angle of the cleavage rhombs. The mineral is often seen to be undergoing replacement by oxides of manganese. The replacement begins along the cleavage cracks and gradually spreads over the whole crystal. The mineral often contains inclusions of yellow spessartite, which also undergo alteration to manganese-ore. Thus the garnet is idiomorphic with regard to the arsenate ; the latter in its 220 MANGANESE DEPOSITS OF (NDIA: MINERALOGY. [ Parr I: turn is idiomorphic towards the quartz. Until these arsenates have been analysed quantitatively it will not be possible to say if they correspond to any known species or are new minerals. It is probable that these arsenates are commoner than is suspected. For it must be noticed that under the microscope they often present a great resemblance to both apa- tite and barytes. All these minerals as seen under the microscope are colourless, with a high index of refraction giving rise to a highly pitted surface. They all show cleavages, and, except in the case of the Kajlidongri arsenate, low polarization colours ; and the tendency is for them all to be called apatite if they are seen only under the microscope. Nevertheless, it is comparatively easy to settle which mineral it is that is present, if the quantity be not too small. In the first place if it be very finely powdered and treated with hot dilute hydrochloric or nitric acid, both apatite and arsenates will pass into solution. It is not then sufficient to add ammonium molybdate to the nitric acid solution and assume that the yellow precipitate indicates a phosphate and therefore apatite. The solution should be first treated with a solution of sulphurous acid to reduce any arsenate if present and then a current of sulphureited hydrogen passed; if a yellow precipitate be formed, it may be assumed that the original rock contained arsenic, probably in the form of arsenate. If no precipitate be formed in this way then the molybdate test may be applied and the yellow precipitate then obtained taken as evidence of the presence of a phosphate, presumably as apatite. If neither an arsenate or apatite be found to be present it will then be as well to make a test for barium by fusing up a portion of the rock with fusion mixture and testing the acidulated extract of this for barium. When the mineral is macroscop- ically visible it is a much simpler matter to prove the presence of either an arsenate or barytes. The arsenic mirror cbtained by heating the mineral with sodium carbonate and potassium cyanide in the closed tube will serve as a good test for the arsenate, whilst the green flame and the blackening of a silver coin will serve as tests to prove the barium and sulphur present in barytes. Distinction of arsenates, apatite, and barytes. I have found barytes in the rocks of the gondite series, apparently as an original constituent, at three localities. For the reason that it may be easily overlooked if one is not on the lookout for it, it is probable that this mineral is much more frequently present in the rocks of this series than I have detected. If its Barytes. Cuap. IX. ] ASSOCIATED NON-MANGANIFEROUS MINERALS. 221 softness be not tested it is liable to be mistaken for felspar in the hand- specimen, on account of its pearly lustre on cleavage faces. Under the microscope it may be mistaken for apatite if its high refractive index combined with its low double refraction be noticed; whilst if one is hurriedly examining a series of rocks, and does not notice the high index of refraction of the mineral, it may be mistaken for a felspar, The localities at which it has been found as a constituent of rocks of the gondite series are Ghoti, Chargion, and Kajlidongri' At Kajlidongri this mineral also forms one constituent of a vein traversing the man- ganese-ore deposit; the other constituents are quartz, the arsenate mentioned on page 219, a black ore, probably braunite, and a small amount of plagioclase felspar. In this vein the barytes indivi- duals may be as much as 2 or 3 inches long. Hxcept for the presence of the manganese-ore and the arsenate, the rock is not unlike the quartz-barytes veins described by Dr. Holland from the Salem district.! These veins are considered to be of pegmatitic origin and to have solidified from an injected mobile magma, From the mode of occurrence of the Kajlidongri vein it would be impossible to decide whether it be an ordinary mineral vein or also of pegmatitic origin; but the presence of plagioclase in the rock renders it improbable that it is an ordinary mineral vein. The arsenate, moreover. may be regarded as taking the place of the apatite so often found in pegmatites, and consequently we can regard the K4jlidongri rock as possibly the product of the solidification of an injected magma. The manganese-ore that it contains may easily have been absorbed by the magma from the manganese-ore deposit at the time of its intrusion. 1 Ree. G. 8. I.. XXX. p. 236, (1897). CHAPTER X. MINERALOGY —concluded. The Identification of Manganese Minerals. I propose to give in this section some hints by the use of which the prospector may attempt to identify the manganese minerals that he meets with in association with the manganese-ore deposits of India, considering at the same time certain non-manganiferous minerals that may be mistaken for ores of this element. [ shall not consider all the manganese minerals that have been found in India as enumerated on page 34; for some of them, such as wolfram, triplite, and columbite, are not found in association with the manganese-ore deposits and are other- wise rare. Of the manganese minerals that occur in the manganese-ore deposit we can first separate off those that exhibit a micaceous structure, this being a very noticeable feature. The micaceous minerals can be red, brown, yellow, or green, in colour and will be found described under the headings of manga- nese-micas (page 195), mangan-chlorite (page 195) and ottrelite (page 199). If the mineral does not show a micaceous structure the first character to be noticed is the colour of the mineral. By far the larger proportion of the minerals found in the manganese deposits will be black, steel-grey or some other shade of dark grey or brownish black, the mineral then usually exhibiting a metallic lustre. The Minerals not black or _.. grey. minerals that are not black can be grouped according to their colours as follows :— Micaceous structure. Colour. CRIMSON TO CRIMSON-BLACK. Piedmontite ; usually in crystalline limestones ; observe pleochroism scheme under the microscope (page !91). Blanfordite ; observe pleochroism scheme under the microscope ; sometimes occurs in characteristic crystals that alter to soft chestnut- coloured pseudomorphs ; also sometimes greenish (page 125). PINK. Rhodonite ; not scratched by a knife ; does not effervesce with hot hydrochloric acid ; rarely greyish-green (page 139). 224 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: Rhodochrosite ; easily scratched by a knife; effervesces with hot dilute hydrochloric acid; sometimes nearly white and always paler than rhodonite (page 122). Rep, ORANGE-RED, ORANGE-BROWN, ORANGE, AND YELLOW, Manganese-garnets ; characterized either by definite crystalline or by granular form, being nearly always equidimensional in all directions ; isotropic character under the microscope (page (61). | Manganese-pyroxenes ; in the Vizagapatam district are some red-brown to orange-brown pyroxenes not to be distinguished from garnets except under the microscope, when they are seen to be anisotropic (page 137). Yellow pyroxenes and amphiboles ; there are also yellow manganese- pyroxenes and amphiboles; the former can only be determined micro- scopically (page 132); the amphibole is usually known by its fibrous or asbestiform character, whilst it may also be brownish or greyish in colour (page 147). BLUE. Winchite (page 149). GREEN. Phosphates and arsenates ; for distinction between these see page 220. All the foregoing minerals will react for manganese except the arsen- ates. The best tests for manganese should be known to every prospector for manganese. They are three in number. A very useful one is to make a borax bead on a platinum wire, in the way described in most books on determinative mineralogy, and introduce a little of the powdered mineral into the bead. If the bead is heated in the oxidizing fiame, the presence of manganese will be indicated by an amethystine colour, which may become deep red if much iron be also present. If the bead is not too strongly coloured it will become colourless when heated in the reducing flame, owing to the reduc- tion of the manganese to the manganous condition. This test works very well with minerals, such as oxides, that are easily broken up in the bead ; but with silicates, such as manganese-garnets, the colour is not obtained quite so readily. The second and the best test is to fuse a small portion of the powdered mineral with a little nitre and fusion mixture or ordinary soda in a platinum crucible, or on a piece of platinum foil bent into the shape of a boat. The presence of manganese in quantity is indicated by a rich green colour ; under certain circumstances the colour is greenish blue, usually when the quantity of manganese is not very large. This is a very delicate test and serves to detect very small quantities of manga- Tests for manganese. Cuap. X.] THE IDENTIFICATION OF MANGANESE MINERALS, 225 nese, the depth of colour obtained with two minerals, under the same circumstances as to relative quantities of mineral and fluxes, being an indication of the relative amounts of manganese present in the two minerals. The green colour is due to the formation of manganates of sodium and potassium. ‘This is the most useful of the tests and the one that is most generally applicable and gives the result desired in the shortest time. The third test is one that is even more delicate than the fusion test. It is known as Volhard’s test and consists in obtain- ing a nitric acid extract of the mineral under examination and boiling it with lead peroxide. Any manganese present is oxidized with the formation of violet or red permanganic acid, the colour being very similar to that of potassium permanganate. This test is only directly applicable to minerals that dissolve in acids. It is best to dissolve the mineral direct in nitric acid if possible. If the mineral has to be dissolved in hydrochloric acid, it is necessary to take the solution nearly to dryness to remove the hydrochloric acid ; for any quantity of this acid prevents the formation of the colour. Ifthe mineral be a silicate it is not as a rule decomposed by acids, so that a fusion is first necessary ; and then the green colour will probably be obtained in the course of the fusion render- ing the application of Volhard’s test unnecessary. Hence this test is only conveniently applied in the case of minerals that are soluble in acids. It has the advantage over the fusion test that it enables one to detect the minutest traces of manganese, such for instance as those to which the colour of rose-quartz may be supposed to be due. We can now pass to the dark-coloured minerals, which usually possess some sort of a metallic lustre. The colours sbown by these minerals are some shade of black, steel-grey, dark blue-grey, brownish-black, or bronze-black. Owing to the fact that there are several fairly common minerals that may be at first sight confounded with manganese-ores, I will also take them into consideration. Supposing that one has found a |piece of a black, or dark grey, or allied-coloured, mineral of consider- able weight, it may be either a manganese or iron mineral, or chromite, or pitchblende, as well as various other minerals of great rarity found but rarely or not at allin India. The first test to apply is to powder the mineral, when the colour of the streak becomes evident. The following table shows the way in which the mineral can be either identified as one of the minerals, hematite, magnetite, ilmenite, pitchblende, or chromite, or else separated off as an ore of manganese, the test that decides whether the mineral is a manganese mineral being the fusion test I Q The black and grey minerals. 226 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part I: with the resultant green colour, as explained above. The key is as follows :— TABLE 19. A key to the identification of the black and dark grey won, manganese, and chromium, minerals. Colour of Powder or Streak.1 (i = ) Red Not red Hematite( and sometimes ) Fuse with nitre and ilmenite. fusion mixture. H=55—6'5 c = a) G=49—5°3 No characteristic Yellow colour. Green colour: Hexagonal. colour. H Chromite. Manganese = minerals. G=43—46 Cubic. Test with magnet. | i (gat ch a ee ee Strongly Weakly or ma Bite nen-magnetic. Maenetite. ( 5 ) H=5'5—6'5 Apply fusior and Make microcos- G=5'16—5:18 tin foil test for mic bead. Cubic. titanium. Opalescent yellow- Violet colour. green colour for | uranium. Ilmenite H=5—6. Pitchblende G=45—5 H=55 Hexagonal. G=90—9°7 Cubic. I have given the hardness (H), specific gravity (G), and crystalline system of each mineral. These characters should be determined as far as possible in order to confirm the identification of the mineral from this key. If the mineral reacts for manganese then recourse should be had to the following key, which is for the identification of the black and dark grey metallic manganese minerals found in India, together with a few not yet found in India, the possible existence of which it is necessary to consider. 1 Limonite is sometimes externally black and mammillated so that it resembles the manganese-ore psilomelane. It is, however, distinguished by its yellow-brown streak andabsence of reaction for manganese. Cuap. X.] THE IDENTIFICATION OF MANGANESE MINERALS, 227 TABLE 20. A key to the identification of the black, dark-grey, and bronze-cotoured, manganese-ores. 228 MANGANESE DDPOSITS OF INDIA: MINERALOGY. TABLE 20. A key to the identification of the black, I. Not scRATCHED BY A PENKNIFE. Manganmagnetite . (Fe,Mn)O.(Fe,Mn)203. 2. Vredenburgite . 3Mng04.2Fe203. 3. Sitaparite . 9Mn203.4Fe203. Mii02.3CaO. 4. Braunite - 3Mn203.MnSiO3 to 4Mn2O03.MnSiOz. 5. Frankiinite . . (Fe.Zn,Mn)O.(Fe.Mn )203. §. Jacobsite . (Mn.Mg)0.(Fe,Mn)203. 7. Polianite - MnOz. 8. Psilomelane. : . mB”’2MnOs +7 B’’’4(Mn05}3; R’=Mn, Ba.Kg, He, ete.; R’’’ = Fe, Mn, Al. | Ree Se | c Crystalline. Non-crystalline. | iC =) 8. Psilomelane. Strongly Weakly or G34 7 magnetic. non-magnetic. Massive and concretionary. ( } 1. Mangan- 2. Vreden- magnetite. burgite. G=about 5 G.=4°74—4'84 Cubic Bronze (octahedral). tint in sun. (; 2 a =. ; Bronze tint. Black, bluish, or steel-grey tints. | i 3. Sitaparite. ( if i i G=4'93—5°09 Gelatinous silica No gelatinous silica Reacts strongly residue. residue. for iroi. 4. Braunite. G=4'75—4°82 Octahedral (tetragonal) and barrel-shaped crys- tals, sometimes twinned. Perfect octahedral cleavage. fi bi Containszine. Contaims no zine. 5. Franklinite. G=5'07—5'22 Cubie (octahedral). a ie | 6. Jacobsite. 7. Polianite 3= 4°75 G=4'83—50? Cubie (octahedral). Tetragonal (prismatic). [ Parr: Cuap. X. ] THE IDENTIFICATION OF MANGANESE MINERALS. 229 TABLE 20. dark-grey, and bronze-coloured, manganese-ores. Il. ScRATCHED BY A PENKNIFE. 9. Pyrolusite - MnOz. 10, Hausmannite, . Mn304. 11. Manganite . Mn203.H20. 12. Hollandite . m R’’2Mn05 +2 R’’’4(MnO5)3; R’’=Mn,Ba,Ca: Rees 8. Psilomelane . . mR”’2Mn05+7 R’’’4(MnOs5)3; R=Mn,Ba,Ko, Ho, etc., R’’’=Fe,Mn, Al. 13. Beldongrite . . 6Mn2Mn0;.Fe203.8H20. 14, Wad. . Indefinite mixture of oxides. i se Crystalline. Non-crystalline. | Fl ie | Very soft. Fairly hard. Homogeneous Very soft, often | and compact. porous, black ] or brown. 9. Pyrolusite. A) | | G=473—4'86 Octahedral Prismatic 14. Wad. Orthorhombie rystalsand crystals and (prismatic). chestnut brownish streak. black to black ee streak. ( Io. Hausmannite. G=4°72—4 86 Tetragonal, > Crystals usually Crystals usually elongated. 11. Manganite. G=4:2_4-4 Orthorhombie, sometimes a bronze tarnish. stumpy- 12. Hollandite. G=4:'70—4°95 Triclinic ? Dull. Shiny; lead-like. 1 8.Psilomelane. G=3 7—4'7 M:ssive and oncretionary. I 13. Beldongrite. G=3'22+ Massive. 230 MANGANESE DEPOSITS OF INDIA: MINERALOGY. [ Part]: Before making use of the foregoing table it is usually necessary to obtain pieces of the mineral to be identified free from admixture with other minerals. Usually the ores are sufficiently coarsely crystalline for this to be simply a matter of breaking up the ore into fairly small pieces and carefully selecting those fragments that under a lens are seen to be pure. Sometimes, however, the granules or crystals of the minerals composing an ore are too small to be conveniently sepa- rated in this way. If the ore is evidently a composite one it is then necessary to resort to methods of separation that it will not be possi- ble to discuss here. Having obtained a portion of the pure mineral, the first test according to the table is to try and scratch it with a penknife. If the mineral can only be scratched with doubt or not at all, then it is probably one of the minerals in the left-hand portion (I) of the table. It must be noticed that although hollandite is grouped with the minerals that can be scratched it is often not possible to scratch its crystal faces, its true hardness being probably about 6 ; but if a knife be drawn across the fibrous fracture of the mineral it will be easily scratched. Hence I have placed hoilandite with the scratchable minerals. Most psilomelane is not appreciably scratched by a knife; but it is sometimes quite soft and therefore the mineral is placed in both sets of minerals (I and II). The soft varieties are sometimes only to be distinguished from wad by quantitative analysis, when psilomelane will be found to conform to the manganate formula given in the key, whilst wad will be found to be an indefinite mixture of oxides. The test for the presence of silica (SiOg) is made by dissolving the mineral in hydrochloric acid. A residue of gelatinous silica can be taken to indicate that the mineral is braunite ; whilst a residue of a few grains of sand or a very small quantity of silica can be neglected. It must be borne in mind that the key is not infallible and that in many cases it will be found to be impossible to decide by its aid to which of two minerals a given specimen corresponds. There is then no alternative to making a complete analysis of a carefully picked specimen of the mineral. It is, for example, often a matter of the greatest difficulty to decide whether a particular specimen is pyrolusite or manganite. This is due to the fact that manganite changes into pyrolusite, and that specimens may be obtained in which this change has not been completed, so that the specimen is intermediate in composition between the two minerals. In the same way it is often difficult to decide whether a particular specimen is to be referred to manganite or hollandite, owing to their similar colour, Remarks on the fore- going key. Cuap. X.] THE IDENTIFICATION OF MANGANESE MINERALS. 231 lustre, and prismatic habit. For although the manganite prisms are characteristically long and thin and those of hollandite stumpy, yet the latter are sometimes fairly long also, and those of manganite sometimes stumpy. A determination of the specific gravity, should, however, settle the point. The only other minerals to which it is necessary to direct attention are the various white minerals that are found in association with the manganese-ores of the gondite series. Quartz there is no mistaking ; but felspar, barytes, and arsenates may easily be confounded with one another, and all regarded as felspar in the field, with the result that a piece of the mineral is not taken away for examination. This also applies to rhodochrosite when it is nearly white. The inferior hardness of the arsenates and the barytes should, however, attract the attention of the prospector. A discussion of the discrimination of those minerals will be found on page 220. White minerals. CALCUTTA: PRINTED BY S8UPDT. GOVT. PRINTING, INDIA, 8, HASTING STRERT. yy SCO 7 » AS. MEMOIRS OP THE GEOLOGICAL SURVEY OF INDIA. VOLUME XXXVII. THe MAnGANESE-OrE Deposits or Inpi4, dy L. Letgn FeErmor, A.R.S.M., B.Sc. (London), F.G.S8., Assistant Superintendent, Geological Survey of India. Part II: GeoLtocy (MoDE oF OCCURRENCE AND ORIGIN). (With Plates 8 to 16.) Published by order of the Government of India, CALCUTTA : SOLD AT THE OFFICE OF THE GEOLOGICAL SURVEY, 27, CHOWRINGHEE ROAD. LONDON : MESSRS. KEGAN PAUL, TRENCH, TRUBNER & CO. BERLIN : MESSRS. FRIEDLANDER UND SOHN. 1909. THE MANGANESE-ORE DEPOSITS OF INDIA PART II GEOLOGY (MODE OF OCCURRENCE AND ORIGIN) 1A CHAPTER >? ABRIDGED CONTENTS OF PART II, X1I.—General, and the Khondalite Series : C XII.—Kodurite Series—Occurrence, Origin, and Chemical Composition : XIII.—Kodurite Series.—Alteration XIV.—Manganiferous Rocks of the Dharwar Facies, including the Gondite Series é - XV.—Gondite Series.—Occurrence and Origin XVI.—Gondite Series.—Mineralogy and Petrology . XVII.—Gondite Series—Chemical Composition and Alteration . XVIII.—Manganese in the Purana, Palaeozoic, and Mesozoic Formations . : . . : : XIX.—Manganese in Laterite : XX.—Manganese in the Tertiary and Recent voumucme THE MANGANESE-ORE DEPOSITS OF INDIA PART I GEOLOGY (MODE OF OCCURRENCE AND ORIGIN) CHAPTER XI. CPO LOGY. General—Classification of Indian manganese-ore occurrences according to formation—The khondalite series. General. The rocks composing the earth’s crust can be divided into two main groups :—(1) the fossiliferous ranging in age from recent to Cambrian; and (2) the unfossiliferous, and as far as is known the pre-fossiliferous, or pre-Cambrian rocks. The word ‘ Archean’ is by many authors taken as synonymous with ‘pre-Cambrian’; but it is customary in America to restrict the word *‘ Archean’ to the older portion of the pre-Cambrian rocks, using the term ‘ Algonkian’ for the unfossiliferous rocks intermediate in age between the Archean and the Cambrian. In India Dr. Holland proposes to use the term ‘ Purdna’, meaning “old ’, to designate the series of rocks occupying a position analogous to that of the Algonkian of America. The Archean rocks can be supposed to form a continuous shell round the earth and to underlie all the younger rocks. These latter rest in more or less isolated patches on the Archean shell, areas of which are now lA 2 The Archean com- plex. 236 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [ Part II: exposed at the surface wherever the denuding agents of Nature have removed the once overlying fossiliferous and Purana rocks. Since the total thickness of the Archean rocks is probably considerably greater than that of the whole of the post-Archzan rocks, by far the larger por- tion of the earth’s crust must be constituted by these ancient rocks. As might be expected, the Archean group is of extremely complex constitution, and may be supposed to be composed The oldest gneisses. é aE Fi of five main divisions :— 1. The original crust of the globe, by which is meant the portion of it that first crystallized out from the molten condition during the secular cooling of the earth. 2. The sediments formed by the denudation and re-deposition of portions of this crust, the denuding and depositing processes being then, however, vastly different to what we now observe, and probably at least as much of a chemical as of a mechanical nature. 3. The igneous rocks intruded from the still molten interior of the earth into the solid or semi-solid crust composed of 1 and 2, These intrusions were, no doubt, taking place during the whole of the time of formation of 1 and 2. Sedimentation and igneous intrusion and extrusion must have pro- gressed side by side, accompanied by a constant crumpling up of the rocks thus formed, with a consequent metamorphism of the whole of them into the gneissic condition. All the gneisses thus formed have been so folded together that to separate them one from another is now in all probability everywhere impossible; especially as these earliest sediments when rendered gneissic must be practically indistinguishable from the rocks from which their material was derived. Consequently all these rocks can be grouped together as the oldest gneisses. 4, Gradually the meteoric conditions must have begun to approach those we now experience, so that true mechanical The schistose gueis- sediments were formed. The sediments formed sesand the Dharwars. : She were then no longer necessarily of a composition approaching that of the original igneous rocks, but composed of conglomerates, sands, clays, and limestones. There must have been a period of comparative tectonic quiescence during which a vast thickness of these sediments was able to accumulate, accompanied by the extrusion in some areas of contemporaneous basic lava-fiows. Both sediments and lava-flows were then involved in another great series of tectonic disturbances and more or less deeply folded in with the Cuap. XI. ] GENERAL, 237 oldest gneisses. Those portions of the sediments that were carried deep down were converted into schistose gneisses, quartzites both massive and schistose, mica-schists, and crystalline limestones, according to the composition of the sediments : whilst those portions that were less deeply folded in were only metamorphosed to the condition of schistose, cleaved, and often felspathic, conglomerates and grits; phyllites and slates; quartzites and sandstone-quartzites; and fine-grained limestones not markedly crystalline. In India such portions of these sediments as suffered the more severe metamorphism, 2.e., that those were rendered thoroughly crystalline, have usually been mapped as part of the crystalline complex, from which they could be separated, in many cases, only by very close field-work : whilst the less metamorphosed portions have been distinguished as the Dharwar system in Southern India; and as the Chilpi Ghat series, the Champa- ners, and the Aravallis in the regions farther north. In this Memoir I propose to extend the name Dharwar to include the whole of these rocks. The set of earth movements that folded the Dharwar sedi- ments was probably the last that affected the whole of the earth’s crust in this part of the world. 5. Partly during and partly after the folding of the Dharwars es: great masses of igneous rocks seem to have been The plutonic intru- - : : sives (Bundelkhand imtruded into all the previously-formed rocks. granite, charnockite Those that were intruded at the time of the folding series, etc. ). paaa : : of the Dharwars have necessarily to a certain extent assumed foliated characters, and are usually known as gneissose granites; whilst those that were intruded subsequently have either no banded structure, or only that due to flow, and can be termed granites, or at the most banded granites. (In other areas where there have been subsequent great earth movements, such as in the Himalayas, such granites have also become gneissose.) These rocks are variously known in the Peninsula of India as the Bundelkhand granite or gneiss, gneissose granite, etc. ; the charnockite series probably belongs to this period. In areas, such as the Peninsula of India, where there have been no violent earth movements since the Dharwar folding, there is of course a great unconformity between all these ancient foliated and schistose rocks and the whole of those that follow. This has been termed the Great Eparchean Unconformity and the period between this folding and The Great Epar- chxan Unconformity. 238 MANGANESE DEPOSITS OF INDIA: GEOLOGY, [ Parr II: the appearance of the next series of sediments the ‘ Great Eparchean interval’. The term ‘Archean’ is conveniently restricted to the rocks lying below this great unconformity, although, as already mentioned, some authors use the term as synonymous with ‘ pre- Cambrian’. Between the end of Dharwar and the beginning of Cambrian times several series of sedimentary rocks, all as far as we know unfossiliferous, have been deposited. Such sedi- ments, originally deposited as sands, clays, lime- stones, etc., are termed Algonkian by the Americans and Purdna by Dr. Holland.’ In areas, such as the Indian Peninsula, that have not been involved in any very intense folding movements since Dharwar times, these sediments have to a large extent escaped any serious altera- tion of their mineral character, and are now represented by quartzites, sandstones, slates, shales, limestones, conglomerates, etc.: they are kuown as the Bij4wars, Kadapahs, Vindhyans, etc. The pre-Cambrian rocks of the Indian Peninsula can therefore be separated into fthe ollowing divisions :— The Puraua forma- tiors. Classification of the pre-Cam brian. I. Archean :— 1. The oldest gneisses (Bengal Gneiss). 2. The schistose gneisses and the Dharwars. 3. The plutonic intrusives, such as the Bundelkhand granite and the charnockite series. If. Purana :— The Bijawars, Kadapadhs, Vindhyans, etc. From these rocks all the later sediments, frequently containing LE hogs fossils, and ranging in age from Cambrian to recent, Derivation of the ; et rocks ranging in age have been formed by denudation and re-deposition, from Cambrian to ejther chemical or mechanical ; except that a small al portion of the detritus has been derived from various post-Purana intrusions of igneous rocks and extrusions of igneous lava-flows at the surface. It follows from this that, for the source of any constituent of the fossi- liferous rocks, we must refer, either immediately or ultimately, to the Archean complex, and, within this complex itself, ultimately to the constitueats of it that are of igneous origin; except that a certain i is 1 Trans. Min. Geol. Inst, Ind., 1., p. 48, (1906). Cuar. XI. ] GENERAL, 239 small proportion of the material has been derived from the igneous rocks of post-Archzan age. Let us take the case of the element manganese. As has already been mentioned (page 18), the earth’s crust contains on The ultimate source the average about 0°10 per cent, of manganese + og manganese- protoxide. Most of this was originally dis tributed in insignificant proportions in the various ferro-magnesian silicates, such as garnets, amphiboles, pyroxenes, and micas, contained in the Archzean igneous rocks. But igneous rocks have also been found in which highly manganiferous minerals form an im- portant part of the rock : thus in the kodurite series of India manganese- garnets and manganese-pyroxenes are found in abundance; whilst the albite-pegmatite of Branchville in Connecticut, United States of America, contains numerous highly manganesian phosphates. The operations of Nature at the surface of the earth on the great variety of rocks exposed to her action are nearly always such as to produce, by either mechanical or chemical means, a concentration at particular spots of particular constituents of the rock operated upon. This has led to the concentration at particular spots, in the form of workable deposits of manganese-ore, of a certain proportion of the once widely disseminated element manga- nese ; and it is now almost impossible to mention a country in which some evidence of the presence of manganese, if not as workable deposits of ore, at least as nodules, impregnations, coatings, or black stains, cannot be found. It follows from what goes before that workable deposits of manganese* fisciuncnepcestdes Ores might be found in rocks of any age whatsoever, posits found in rocks all thai is required being a favourable combination of any age. of circumstances, either mechanical or chemical, enabling the reQUisite concentration to be effected. Suchis found to be the case. Thus the deposits of Brazil and most of those of India lie in the Archzan rocks, those of Arkansas and the Appalachian region of the United States chiefly in the Paleozoic, those of Carniola in the Trias, and those of the Caucasus in the Eocene. Although most of the workable manganese-ore deposits of India occur Re tal OE | in rocks of Archean age (those in laterite forming manganese-ores and the exception), yet manganese-ores and minerals minerals of India ac- have been recorded from a variety of formation.s cording tofurmations These are set forth in the following table, the oldest rocks being placed first and the youngest last. It must be noted 240 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [ Part II: that the manganese minerals, especially the oxides and manga- nates, were not in all cases, or even usually, formed contempo- raneously with the rocks in which they occur, and that in many cases they were formed at some unknown period between the time of formation of the rocks in which they occur (this is what is given in the subjoined table) and the present. TABLE 21. Classification of Indian occurrences of manganese-ore and manganese minerals according to their geological position. Group. Formation or Series. Localities, Archean - | Khondalite Series . . | Ganjam, Vizagapatam. | Manganese-intrusives (Kodurite Vizagapatam, Ganjam. Series). ) | Dharwar Facies :— Metamorphic schists . . | Balaghat, Bhandara, Chhindwara, and gneisses (Gondite Series).|_ Nagpur, and Narukot. Aravyali 4 : , . | Banswara, Jhabua, Jhang, Patiala, Ajmere, and Alwar. Champaner . : 2 . | Panch Mahals. Chilpi Ghat Series . . | Balaghat. Dharwar (mostly lateritoid) . [Belgaum (Bhimgad), Dharwar, (Tawar- gatti), Sangli, North Kanara, Jabal- pur, Bellary, Sandur Hills, Chital- drug, Shimoga, Tumkur, Singh- bhum. and Kalahandi. Occurrences of small quantities of | Gaya, Hazaribagh, Monghyr, Palan- maNganese-ores and minerals. pur, Malvan, Amherst, Karenni, Mergui, Ruby Mines district, Tavoy, Haidarabad, Kashmir, Coimbatore, Madura, Nellore, Salem, Bangalore, and Hassan, Purana . . | Kaladgi - Z fa . | Belgaum (Munnikerri), Bijapur (Bagalkot and Kaladgi). Bijawar . 3 6 - . | Dhar, Indore, Hoshangabad, and Gwalior. Vindhyan 5 < . | Bhopal, Rewah(?), Nimar. Krol : ; : - . | Kangra (Dharmsala). Jaunsar . A A s . | Jaunsar. Dravidian . | None ; unless the Krol and Jaunsar rocks belong here Cuar. XI. ] KHONDALITE SERIES. 24] Classification of Indian occurrences of manganese-ore and manganese minerals according to their geological position—contd, Group. Formation or Series. Localities. Ironstone shales . | Burdwan. Arvan . Gondwana + Kamthi E . | Nagpur (Siliwara), Wun (Yeotmal), Jabalpur : . | Rewah. Liassic . c = ‘ - | Baluchistan. Lameta : js j . | Dhar, Indore, and Nimar. Deccan Trap .- : : - | Belgaum, Dharwar, Ratnagiri, Satara, and Amrdaoti. Laterite?. : ; F - | Morbhanj, Belgaum (Talevadi), Bija- pur (Ingleswara), Dharwar (Nagar- gali), N. Kanara(?), Jabalpur, Goa, Bidar, Chengalpat (Red-Hills), and the Nilgiris. Lithomarges on the charnockite | The Nilgiris. series. Lateritic gravel : : - | Ganjam (Gudhiari), Nagpur, Bhan- dara. Pre-Tertiary (exact position | Andamans, unknown): Nummulitie . : ‘ . | Kohat. Sabathu ; . | Afghanistan. Fossil-wood group (Pliocene) . | Taung-ngu, Magwe. Post-Tertiary . : - | Hantha-wadi. Recent (various) . ; . | Dhar( Pan Kuan), Nagpur (Pench R.), Allahabad (bones), Ganjam (Ram- bha and Kalikot), Chitaldrug (black soil), and 24 Parganas. Recent (Sands) : : . | Haidarabad, Coimbatore, Karnul, Nellore. Recent (deep sea). - . | Maldives. Fault-rock of various ages. . | Bundi, Dhar, Indore, Nimar, 1 Also see iateritoid under Dharwar. Khondalite Series. (Vizagapatam, Ganjam and Orissa.) The term khondalite was given by Dr. T. L. Walker ! to a series of rocks supposed to be para-schists or metamorphosed sediments ; they form, together with garnetiferous biotite gneissose granites and rocks of the charnockite series, the great ellipsoidal outcrop of Archean erystallines that stretches in a north-easterly direction through Godavari, Vizagapatam, Kalahandi, and Ganjam, to Orissa, and that gives rise to the mountain or hill ranges known as the Eastern Ghats. The khondalites are composed essentially of garnet, sillimanite, quartz, and graphite ; but 1 Mem. Geol, Surv. Ind., XX XIII, pt. 3, p. 11, (1902). 242 MANGANESE DEPOSITS OF INDIA: GEoLoGy, [ Parr II: it seems to have been previously overlooked that everything black in the khondalites is not graphite. In several cases where I have tested little black spots and areas in these rocks, they have turned out to be manganese oxide. One such occurrence near Sandapuram in the Vizagapatam dis- trict is noted on page 1115. Near Kalikot in Ganjdm little veins and patches of psilomelane are common in an accumulation of boulders of khondalite (see page 1037) ; whilst among some specimens of: khondalite sent as examples of building stone from Orissa, there were two from Khigerimudia, 3 miles south of Jatni near Khurda Road Station, Puri district, showing spots and streaks up to 14 inches long of soft black manganese oxide giving a brownish black streak. In none of these cases is the manganese oxide, as such, an original constituent of the rock ; it has always been deposited in its present form subsequent to the formation of the rock. According to the analysis shown by Walker!, khondalite does not contain manganese; but one may suspect that this rock, like most of the ancient crystallines, contains at least a small amount of this element, and that during the action of the weathering processes on those portions of the khondalites lying near the surface the manganese is dissolved out by circulating waters, and re-depo- sited where the conditions are suitable, this re-deposition being accom- panied by a metasomatic replacement of the rock. Some of this manganese oxide, however, has probably been derived from rocks other than those of the khondalite series, such as the manganese-intrusives (kodurite series) of Vizagapatam. § 1 Mem. Geol. Surv. Ind., XXXII, pt. 3, page 9, (1902). CHAPTER XII. GEOLOGY —continued. The Kogurite Series of Vizagapatam and Ganjam. Vizagapatam district—Calcareous gneisses—The kodurite series—Relations to other crystallines—Igneous origin—Nomenclature—Mineralogy—Petrology— Magmatic differentiation—Localities—Occurrence in the Ganjam district—Chemical composition. Vizagapatam District. Lying to the east of the Eastern Ghats noticed above are the coastal plains of Vizagapatam, some 30 to 50 miles wide and not rising to any very great height above sea level. These plains are composed, as far as can be discovered from the scattered outcrops between the patches of alluvium, of a complex of Archzan crystallines of which the two main constituents are the gneissose granites and the khondalites noticed on page 241. These rocks often give rise to small tors and hills, respectively, protruding through the alluvium. Associated with the khondalites, usually at their junction with the gneissose granites, are some very calcareous gneisses regarded by Walker as a part of eee or the khondalite series and, like the khondalites, : formed by the metamorphism of sediments. Mineralogically, these gneisses are of very variable composition, but are usually composed of pyroxene (macroscopically dark to light green, microscopically light green to colourless; probably diopside), wollastonite, scapolite, garnet (orange-brown macroscopically, and light brown to yellow-brown microscopically), calcite, and sphene. Microcline, orthoclase, plagioclase, quartz, and apatite, are less frequent constituents. It is difficult to find a name that can be used so as to include all the varieties of these rocks. Thus the term scapolite-gneiss is not generally applicable, because scapolite is frequently absent. The most constant mineral is the pyroxene. But there are so many varieties of pyroxenic gneisses that it would be better to avoid this term if possible. Now it so happens that nearly all the minerals in these gneisses contain an abundance cf lime, this richness in lime being in fact the most character- istic feature in the chemical composition of these rocks. Hence I propose to refer to them as the calcareous gnevsses or, for short, the calc-gneisses, 244 MANGANESE DEPOSITS OF INDIA: GEOLOGY. f[ Part IL: Should anyone object to this term as implying that calcite is always present in these rocks, which it is not, the termjlime-gneisses could be used ; it is to be noted, however, that the term calcareous refers to the presence of lime and not of calcium carbonate. Rocks of the charnockite series are not met with until the outer edge of the Eastern Ghats is reached, as at Taduru. Allthe manganese-ore deposits now being worked are situated in the coastal plain country, and, as has been already explained elsewhere!, are regarded as derived by chemical alteration from rocks of which the chief constituents are apatite, a manganese-garnet (spandite), manganese-pyroxenes (at least two species), potash-felspar, and quartz. This series is evidently quite different from the other series of rocks in this district, and in fact I am not aware that rocks of a similar character have been previously described. Hence, I propose to call this series the kodurite series after the Kodur mines where its constituent rocks are well exposed?. From the foregoing it wil! be seen that the rocks of this area, including Relatiops of the te outer fringe of the Eastern Ghats, where also kodurite series to the Some occurrences of manganese-silicate-rocks have other crystallines. heen - detected, can be separated into the fol- lowing petrological groups :— The kodurite series. 1. Kodurite series. ) . Charnockite series. § Igneous. 3. Gneissose granite. 4. Cale-gneisses. 5 : 5. Khondalite series. 5 Metamorphic. 6. Contact products of 2 and 5°. The relative ages of these rock groups are difficult to determine ; for they seem to be regularly interbedded one with the other, and clear sections showing the contacts of rocks of the different groups are rare. Dr. Walker, however, supposes the khondalite series, including groups 4 and 5 above, to be older than groups 2 and 3; forit was possibly the intrusion of these latter rocks that led to the metamorphism of ancient sediments into the rocks of groups 4 and 5, The outcrops of the various rocks at the surface take the form of parallel bands, and, as far as has been revealed by mining operations, the 1 Rec. G. S. I., XX XIII, pp. 96, 97, (1906); Trans. Min. Geol. Inst. Ind., I, pp- 87, 88, (1906). 2 This name has already been announced in Rec. G. 8. I., XX XV, p. 22, (1907). 3 T. L. Walker, Rec. G. 8. I., XXXVI, p. 1, (1907). Cuap. XII. ] KODURITE SERIES. 245 kodurite series forms no exception to this rule. The rocks of this series have nowhere been found in close relationship with the rocks of the eharnockite series, except in the Eastern Ghats; whilst their rela- tions to the rocks of groups 3 to 5 are usually obscure. Except at Chintelavalsa and Taduru in the Eastern Ghats their junctions with the neighbouring rocks are not seen at the surface. At the two localities just mentioned the kodurite rocks are not typical of the series ; for they are composed very largely of the pyroxenic element. As will be seen from the sections given on Plate 55 and page 1114, the succession of rocks at these two places is as follows (in descending order) :— Téduru. Chintelavalsa. Hs hondalite: 4. Calcareous gneiss. 2. Biotite-pyroxene-gneiss. 3. Manganese-silicate-rock. 3. Manganese-silicate-rock. 2. Biotitic gneiss. 4. Calcareous gneiss (scapolitic). la. Caleareous gneiss. 5. Gneissose granite. 1. Khondalite. The numbers indicate what are probably corresponding horizons, if indeed such correspondence can be looked for in rocks of such anti- quity at localities 5 miles apart. If this correlation be correct, it is clear that the rocks at one locality have been inverted. The rock overlying No. 4 at Chintzlavalsa was unfortunately not observed. The evidence of these two sections, however, is that the manganese-silicate rocks are more closely associated with the calcareous or scapolitic gneisses and the biotite-pyroxene-gneisses (not observed elsewhere), than with either the khondalites or gneissose granites, Indeed, from the evidence of these two sections, one might suppose that the manganese-silicate-rocks are merely metamorphosed manganiferous sediments occupying a definite position in the succession of aluminous and calcareous sediments from which Walker supposes the khondalites and calcareous gneisses respect- ively to have been derived. The rock No. 2 contains a rhombic pyroxene, and Dr. Holland, to whom I showed the specimens and microscope slides, thinks it is probably a somewhat abnormal member of the charnockite series. At no other localities were such clear exposures seen, or the manganiferous rocks in such a fresh condition. All the other manganese deposits that I visited were situated in the plains, where alluvium largely obscures the geology, and where, had no mining been attempted, all that the geologist could see would be long low mounds of manganese-ore and manganese-silicate-bearing rocks conforming in their general direction to the strike of the ridges of khondalite, calcareous 246 MANGANESE DEPOSITS OF INDIA: GEOLoGy, f[ Part IT: gneisses, or gneissose granite, that crop outa little distance away on either side of the manganiferous outcrops, the intervening ground being covered by alluvial soil. At most of the localities visited, namely, the Kodur mines, Perapi, and Kotakarra II, calcareous gneisses were found cropping out on the low ground close to the manganese-ore band, whilst at the remainder, the following were the nearest exposed rocks :— Garbh4m,—Quartz-rock close to the deposit, garnet-bearing quartzites some 1,500 feet to the south, and gneissose granite some 1,500 feet to the north, of the west end of the manganiferous band. Kotakarra I.—Coarse quartzite or vein quartz some distance away. Avagudem,—Immediately to the north is a low ridge of white quartz and white garnetiferous quartzite passing to the east into a high ridge of khondalite. Rémabhadrapuram,—In the excavations the manganiferous rocks are in contact with laminated quartzites, sometimes garnetiferous ; whilst in another place, on the open ground between the Sonpuram and Mamidipilli workings, there is an outcrop of banded pyroxenic quartzite. The only cases in which the mining operations have clearly revealed the rocks immediately adjacent to the kodurite rocks! are (1) at Devada (page 1074), where the calcareous gneisses are seen in the excavations to form the western wall of the kodurite band; (2) at Perapi, where felspathic khondalite is seen to overlie the ore-band and associated fels- pathic rocks (page 1078 and fig. 83 ); and (3) at Ramabha drapuram, where quartzites are seen (above). The quartzites (often garnetiferous) noted above as occurring in proxi- mity to the manganese-ore bands may be regarded as forming a part of the khondalite series. Hence we see from the evidence given above that the bands of the kodurite series seem to be more closely associated with the khondalite series and the calcareous gneisses than with the gneissose granites. Regarding for the moment the khondalites and calcareous gneisses as forming a succession of metamorphosed sediments, it is seen that the evidence, scanty as it is, does not bear out the theory suggested by the Taduru and Chintelavalsa rocks that the manganese-silicate-rocks 1 As will be explained later, the large masses of decomposed felspathie rocks that often form the immediate ‘country’ of the manganese-ore bodies and are well exposed in several of the quarries are considered to form a part of the kodurite series, Cuap. XII. } KODURITE SERIES: IGNEOUS ORIGIN. 247 occur at any definite horizon in this succession. Sometimes they are most closely associated with the calcareous gneisses and sometimes with rocks of the khondalite series. This prepares the way for the hypothesis that the rocks of the kodurite series are of igneous origin intrusive in the khon- __ The kodurite series of qdalites and the calcareous gneisses. As will be + ea shown later, the chemical and mineralogical composition of these rocks point very strongly to their igneous (plutonic) origin. As they have nowhere been seen in contact with the gneissose granites it is impossible to say which is the older series. If the granites be the older then it is evident that the manganese- intrusives must have intruded themselves into the calcareous gneisses and khondalites as being less massive rocks. It is evident that with such well-bedded rocks as the calcareous gneisses and khondalites, the path of least resistance for the intrusions, would be, wherever the rocks were dipping at moderately high angles, along the bedding planes. This would account for the fact that everywhere the strike and dip, when observable, of the manganese-bearing rocks conforms to that of the neigh- bouring calcareous gneisses or khondalites. As an example of the way in which this intrusion may be supposed to have occurred, two alternative hypothetical sections across the Kodur kodurite-belt at Sandananda- puram are given on page 1053,! The second of these sections is construc- ted on the hypothesis that the kodurite intrusions took place subsequent to the consolidation of the gneissose granites. It may be thought that the very fact of the non-observance of any trespass of the kodurite series across the boundaries of the other rocks should be taken as an argument against the igneous origin of these rocks. It is therefore necessary to notice that— (1) very few contacts of the kodurite series with other rocks have been noticed? ; (2) the kodurite series has evidently, in at least some cases, such as Taduru, Chintelavalsa, and Garbham (see fig. 88, page 1088), been subjected to earth-movements whilst included between the present wall rocks, and such move- ments would tend, especially if the rocks were still deeply buried in a region of high temperatures and pressures, 1 See also Trans. Min. Geol. Inst. Ind., I, p. 90, (1906). 2 Even the Taduru and Chintelavalsa sections are constructed from the outcrops of the rocks and not from any clear section exposed by a stream cutting through the rocks, 248 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [ Part II: to obliterate any minor evidences of intrusive relations, partly by rolling or crushing of the boundaries of the two rocks, and partly by reactions producing mineralo- gical re-arrangement at the junctions between rocks of different chemical composition, as in the case of the special rocks formed at the contacts of the charnockite and khondalite series in this very district!. But it must be admitted that in most cases there is little or no evidence that the kodurite series has suffered much from earth-movements since its presumed intrusion. At Ramabhadrapuram there is exposed in one of the pits a band of quartz-microcline-rock which, since it contains the greenish blue apatite characteristic of the kodurite series, with which it is associated, may be supposed to form a part of this series. The structure of the rock is such as to suggest a pegmatite that has moved at the time of solidification. The only remaining argument in favour of the igneous origin of the kodurite series is the presence of two large xenoliths of crystalline limestone in the masses of lithomargic rock at Kodur (see page 1065). Their position is best explained on the supposition that they are masses torn off and brought up from below by the kodurite intrusion. '_ The evidence in favour of the igneous origin of the kodurite series can therefore be summed up as follows :— (1) The mineralogical and chemical composition of the rocks, which could only with difficulty be explained on any other hy- pothesis (see page 261), (2) The signs of magmatic differentiation (see page 254), (3) The supposed included xenoliths of crystalline limestone at Kodur. (4) The pegmatoidal variety at Ramabhadrapuram. (5) The varying horizon that the rocks of this series occupy in the succession of calcareous gneisses and khondalites. (6) The fact that in two cases, Chintelavalsa and Taduru, they are also associated with rocks that probably belong to the charnockite series. The only point that seems to be adverse to the igneous theory is the absence of any observed intrusive relations of the kodurite series with respect to the calc-gneisses and khondalites. This, as shown above, is easily accounted for. 17. L. Walker, Rec, G. 8, I., XXXVI, p. 1, (1907), Cuap. XII. ] KODURITE SERIES : NOMENCLATURE, 249 Owing to the long continued chemical changes by which the manga- nese-ores have been produced from manganese silicates, the masses of the kodurite rocks as seen in mine workings are usually found to be extremely altered. In fact it is practically impossible to find perfectly fresh examples of any of the rocks of this series ‘except, perhaps, at the non-typical localities, Taduru and Chintelavalsay. Hence, one usually has to judge of the original composition of the kodurite rocks by carefully noting how in one place one mineral constituent has been decomposed, and in another place another constituent; and as the result of examining a large number of the many exposures to be found in the various workings, especially at Kodur, Garbham, and Rama- bhadrapuram, it has been found comparatively easy to arrive in this manner at the original mineralogical composition of the rocks of this series. The typical rock of the series is one composed of potash-felspar, manganese-garnet (spandite), and apatite, with or Nomenclatureofthe without pyroxene. This rock may be called kodurite kodnrite series. ss é when pyroxene is absent and pyroxene-kodurite when this mineral is present. When quartz is present the rocks can be distinguished as quartz-kodurite and quartz-pyroxene-kodurite respectively, A biotite-kodurite has been found at Ramabhadrapuram, this and a mica- bearing manganmagnetite-spandite-rock from Garbham being the only mica-bearing examples of this series yet noticed!. The manganese- garnet may be regarded as the characteristic mineral of this series. To obviate the constant use of the cumbrous term manganese-garnet and to express the fact that this garnet, though probably very variable in composition, is intermediate between the manganese-alumina garnet, spessartite, and the lime-iron garnet, andradite, the term spandite has been coined (see page 163). Hence those rocks that are practically free from felspar may be called spandite-rock, apatite-spandite-rock, pyro- xene-spandite-rock, etc., according to their composition. Those rocks composed mostly of pyroxene may be called manganese-pyrozenites ; whilst those varieties that are free from spandite and pyroxene may be called felspar-rock, and quartz-felspar-rock, etc. There is also an apatite-manganmagnetite-spandite-rock containing a little mica ; but it is uncertain if the manganmagnetite be an original constituent or not. Although very little analytical work has yet been done on the rocks of the kodurite series, yet, on the basis of their mineralogical composition, 1 The complex rock found at Chintelavalsa (see page 1114) also contains mica- IIB 250 MANGANESE DEPOSITS OF INDIA: GEOLOGY, [ Part II : it is possible roughly to divide them into groups, according to what may be assumed to be the silica percentage of the particular rocks. The classification would be somewhat as follows :— Quartz-orthoclase-rock. Apatite-quartz-orthoclase-rock. Acid. Quartz-kodurite in part. Quartz-kodurite in part. Orthoclase-rock. Kodurite. Pyroxene-kodurite. Biotite-kodurite. Spandite-rock. Apatite-spandite-rock. Pyroxene-spandite-rock. Ultra-basic. Manganese-pyroxenites. Graphitic manganese-pyroxenites. Intermediat . Basic. a ood Many of these rocks grade one into the other as one mineral constituent becomes more abundant and another decreases in quantity. The rocks grouped as ultrabasic are non-felspathic, whilst all the others contain felspar, which is found to be a potash variety, probably orthoclase, wherever it is sufficiently fresh to be tested. Apatite occurs in smaller or greater quantities im all the rocks. Intimately associated with the kodurite series are various varieties of vein-quartz and pegmatite. At Garbham a very Pegmatite and vein siliceous pegmatite clearly cuts the kodurite series ; eee whilstat Kotakarra II, a quartz-felspar-pegmatite just as clearly cuts the kodurite rocks. These rocks may hence be sup- posed to be of subsequent age to the kodurite series. In some places, however, as at Kodur, small veins, not continuous for any length, are seen in the lithomarges. Their small extension may simply be due to the breaking up of more extensive veins by the slipping of the masses of lithomarge ; but, in any case, one cannot help wondering if this quartz and some of the pegmatite be not the most acid varieties of the kodurite series. The apatite-bearing pegmatite of Ramabhadrapuram has already been referred to (page 248). The minerals so far found in the rocks of this series are :—Quartz, felspar, apatite, spandite, three or four manganese- Bet ofthe pyroxenes (one of them rhodonite), biotite, graphite, and sphene, the three last-named minerals being of rare occurrence, and possibly mangan-magnetite. This is Cuap. XII.] KODURITE SERIES ; MINERALOGY. 251 neglecting, of course, all minerals, such as manganese-ores, lithomarge, and chert, that have been formed by subsequent alteration. Quartz.—This is usually found in the most acid varieties of the series, and when it occurs the rock is as a rule sufficiently coarse-grained for the quartz to be about } inch in diameter, the range for this consti- tuent being usually about } to § inch. The quartz is white to colouriess. Felspar.—This is usually completely altered to lithomarge (kaolin), but is fairly often found forming a crumbly mass that gives a marked potash reaction. In rocks from Boirani in Ganjam (page 255), however, it is found perfectly fresh, preserved in a matrix of secondary opal (see fig. 2, Plate 8). It then shows under the microscope the characters of orthoclase. A specimen of kodurite from Mamidipilli is a friable granular rock in which the constituents average 4 to + inch across, the felspar being fresh though very brittle. This also gives a strong potash reaction, and is seen under the microscope to be untwinned. The evidence therefore shows that the felspar is an untwinned potash variety and hence probably orthoclase. It is usually allotriomorphic, but in the granular rock from Mamidipilli mentioned above it is sub-idiomor- phic, whilst in one specimen from Boirani in Ganjam there is a porphyritic crystal (0°3 inch long) showing simple twinning. * Apatite—This is the most universally distributed constituent, for it may be found in every variety of the rocks of this series. In some cases it is only seen microscopically ; but it is frequently present in little rounded bluish-green prisms from ;'; to + inch long, and can often he extracted in great abundance from the decomposed lithomarge that has been formed from the felspar of the original kodurite. At Garbham, Raémabhadrapuram, and Devada, it is especially abundant in this way. On page 1073 the find at Devada of some hundredweights of deep sea-green apatite in rough prisms up to 5 inches diameter is noticed, and it is suggested that they may have been derived from a pegmatitic variety of kodurite. Analysis is said to have shown this to be fluor- apatite. On page 1063 is described the occurrence at Kodur of a veinlet of lavender-coloured apatite in spandite-rock. Both this and the Devada crystals are mangan-fluor-apatite. Spandite——In the spandite-rock this occurs in granules averaging. at Kodur, 4 to } inch in diameter. As the grains are all in contact with one another they are bounded by flattish faces, which do not cor- respond to any particular directions. In kodurite the spandite is found both aggregated and in separate granules. These granules are usually 11 B 2 252 MANGANESE DEPOSITS OF INDIA: GEOLOGY, | Part II: about ;'; to } inch in diameter and are either well rounded or partly bounded by small unrecognizable faces. They often show a bright lustre and, on a fresh fracture, are seen glistening from the light-coloured matrix. The spandite varies in colour in the rocks of various locali« ties from deep orange to orange-red and blood-red, and never shows the yellow and lighter orange colours of the spessartite of the Central Provinces. Under the microscope these garnets show various tints of pale-yellow, pale orange, and pale orange-brown. Manganese-pyroxenes.—The least common of these is a rose-pink py- roxene, probably rhodonite. This is best seen at Chintelavalsa and Taduru, where it forms a coarsely crystalline rock composed of varying proportions of rhodonite and the other manganese-pyroxenes, with a certain amount of orange-coloured garnet. It is not certain whether there are only two other pyroxenes besides rhodonite, or three. These other pyroxenes are also best seen at Chintelvalsa and Taduru, where they form a coarsely granular rock with rhodonite. The supposed three varieties are brown, green, and brownish green, in colour, and an account of them is given on page 137. As the first-named is cften of a rich orange-brown colour, it may easily be mistaken macroscopically for the manganese-garnet. The pyroxene seen at Kodur is usually entirely changed into a pseudomorph of soft brownish black manganese oxide still showing the cleavage of the , pyroxene ; but, where less altered, it appears to be blackish green. Until the manganese-pyroxenes of the various localities are critically ex- amined it will be impossible to say how many species or varieties there are. At Kodur some of the altered forms of pyroxene are an inch and more in diameter. Biotite—This is found at Ramabhadrapuram and shows the ordinary pleochroism, brewnish straw to dul] orange-brown ; it might, from its mode of occurrence, be expected to be manganiferous, but this point has not been determined. It also occurs at Chintelavalsa in a complex rock composed of spandite, rhodonite, green pyroxene, quartz, apatite, sphene, and graphite, and at Garbhém in apatite-manganmagnetite spandite-rock. Graphite-—This is abundant in the Chintelavalsa rock noticed in the preceding paragraph. It occurs in scales up to 4 inch diameter, Tf is also found in varicus rocks at Taduru (see page 1112). Sphene.— The only occurrence is in the rock mentioned under ‘ biotite’, in which it occurs in small crystals distinguishable only under the microscope. Cap. XII. ] KODURITE SERIES: PETROLOGY. 253 Manganmagnetite—On page 40 will be found an account of the apatite- manganmagnetite-spandite-rock of Garbhim. It is not iraprobable that this manganmagnetite is of primary origin, although the evidence ene way or the other is not conclusive. In a series of rocks containing basic and ultra-basic members cne would expect the presence of a black ore. In the ordinary basic and ultra-basic rocks such as gabbros and peridotites black ores are common, taking the form of ilmenite, magnetite, and chromite. In the case of the kodurite series we should expect any ore if present to contain manganese, and perhaps mangan- magnetite would be the most likely mineral. Hence it is not unreasonable to suppose that the manganmagnetite of this Garbham rock is an original constituent. As this mineral is often found in the manganese-ores of this area, the question naturally arises as to whether such manganmagnetite also is original, so that it is the only mineral left unaltered during the chemical changes by which the manganese-ores were produced; or whether it is, like the remainder of the manganese-ores, of secondary origin. There is at present no evidence available that will enable this point to be determined. I do not intend to give here any detailed description of the rocks Petrology of the Of this series. A short account of the minerals kodurite series. has just been given and by reading this and the notices of the various rocks scattered through the descriptions of the deposits, a very good idea of the characteristics and mode of occurrence of these rocks will be obtained. Taken as a whole these rocks are of medium grain, being either of about the same degree of coarseness as an ordinary medium-grained granite, or of somewhat finer grain (constituents averaging 1, to + inch diameter). The apatites and garnets are often scattered as rounded idiomorphs in the remainder of the rock. The rocks do not usually shew banding, but at TaJuzu there is a distinct tendency to shew this characteristic, as also at Kotakarra. It will, however, be interesting to consider the typical kodurite. As already stated this has nowhere been found unaltered. But as the processes of alteration have usually acted so as to affect different consti- tuents at different places, it is easy to reconstruct the original rock. Judged in this way, the unaltered kodurite must have shewn red-brown garnet crystals, usually averaging ;'; to } inch diameter, profusely scattered through a light-coloured matrix of white orthoclase (averaging } to } inch diameter), and greyish to greenish-blue rounded apatite prisms (averaging ;'; to ;°; inch diameter), the apatite being usually much less 254 MANGANESE DEPOSITS OF INDIA: GEOLOGY, [ Part IL: abundant than the felspar. The garnets were both isolated and in little aggregates, and sparkled from the reflections from tiny faces, though on the whole they were rounded. The proportions of the constituents are, however, very variable so that it is not possible to give any definite chemical composition for the rock. Judging merely from appearances, the proportions by volume would be somewhat as follows in typical kodurites :— Spandite L Spandite : : 3 Apatite . 1 to Apatite . ; . : i Orthoclase 4 Orthoclass . $ there being every gradation from these to rocks composed entirely of spandite and apatite, or entirely of orthoclase. On examining such mines as Kodur it is found that the more basic Magmatic differentia. TOcks, such as spandite-rock, occur as large patches tion of the kodurite and streaks, surrounded by zones of less basic com- in position such as kodurite, in a general matrix of quartz-felspar-rock or felspar-rock, the most acid members of the series. Assuming for the moment that the mineral composition of the rocks is sufficient to show that the kodurite series is of igneous origin, then it is found that the relations of its varicus members are easiest explained as being the result of magmatic differentiation, by which patches and streaks of the more basic rocks have separated out from the general magma, leaving the latter of a somewhat more acid composition than it otherwise would have been. It seems probable that this differentiation took place before the eruption of the magma and that the basic segregation patches thus formed were drawn out into streaks when the magma was intruded into its present position. Had the differentiation taken place after erup- ion we should have expected to find the more basic rocks located on the margins of the intrusions and the more acid rocks in the centre. The very opposite is, however, the case. Thus at Garbham the ore-band, which corresponds to the original manganese-silicate-rocks, occupies a roughly central position with regard to the masses of lithomarge, corres- ponding to the original felspathic rocks, which form the north and south walls of the quarry (see figures 87, 88, pages 1087, 1088). Occurrences of the various rocks of this series will be found mentioned Localities for rocks in Part IV under the localities shown in the follow- of the kodurite series. jing list. This list will also give some idea of the relative abundance of the various rocks. Cuap. XII.] KODURITE SERIES: GANJAM 255 List of localities for the members of the kodurite series. Quartz-vcthoclase-rock.— Kodur, Devada, Perapi, Garbham, Avagudem, and Rame«bhadrapuram. Orthoclase-rock.—Kodur and Garbham. Quartz-apatite-orthoclase-rock.— Ramabhadrapuram. Quartz-kodurite.—Devada, Garbham, and Ramabhadrapuram. Kodurite.—Kodur, Devida, Perapi, Garbhiam, Kotakarra, Ramabhadra- puram. Pyroxene-kodurite.-—Kodur. Biotite-kodurite—Ramabhadrapuram. Spandite-rock.—Kodur, Garbham and Chintelavalsa. Apatite-spandite-rock.—Kodur and Sandapuram. Pyroxene-spandite-rock.—Kodur, Perapi, Chintelavalsa, and Taduru. Manganese-pyroxenites.—Kodur, Chintelavalsa, Taduru, and Kantikapilli. Graphite-bearing manganese-pyroxenites.—Chintelavalsa, Taduru. Vein-quartz.—Kodur. Pegmatite.—Devada, and Ramabhadrapuram. Ganjam District. In view of the fact that the garnet contained in the specimen of rock from Boirani, of which the calculated analysis is given on page 258, contains such a small proportion of manganese compared with the garnet found in the kodurite rocks of the Vizagapatam district, it seems at first sight doubtful if the Ganjam rocks be really the same series as the kodurite series of Vizagapatam district. Considering, however, tue similarity of the rocks of the two areas in their other constituents and the fact that they both give rise to manganese-ore deposits on alteration and are otherwise subject to the same kinds of alteration, it seems probable that the two series are genetically the same, the only difference being that there is a considerable difference in the composition of the garnets contain- ed in the rocks of the two areas as represented by the two specimens analysed. This difference may indeed be accidental and the analysis of a large number of specimens of these rocks from the two areas might show that there is a great variation in the composition of the garnets through the isomorphous replacement of one constituent of the garnet by another. But even if the manganese-garnets of the Vizagapatam rocks constantly contain a greater percentage of manganese than the manganese-garnets of the Ganjam district, the petrological and miner alogical resemblances of the rocks of these two areas are sufficiently close for them to be regarded as one and the same series until evidence to the contrary can be produced. Hence the term kodurite can be extend- ed to the manganese-silicate-rocks of Ganjam. 256 MANGANESE DEPOSITS OF INDiA: GEOLOGY, [Parr Ii: Chemical Composition of Kodurite. To get at the original composition of kodurite I picked out the two freshest examples I could find. One of these was a banded variety from Kotakarra in the Vizagapatam district. In this rock the garnet and apatite are still fresh, whilst the felspar has been entirely replaced by opal. Microscopic examination shows that this replacement by opal has been practically confined to the felspar, although a little garnet or apatite are perhaps occasionally affected. In the calculations given later on it is assumed that the replacement is entirely confined to the felspar. The rock usually shows small patches of black manganese oxides in places, but the piece selected was free from these stains. After prolonged soaking in water and finally boiling for some hours the specific gravity of this specimen was found to be 2-851. This treatment was necessary because the rock was evidently porous and showed under the microscope numerous cavities in the opal; since some of these were perhaps closed, the specific gravity given above is probably a little lower than the value that would have been obtained if the specific gravity had been determined on the powdered rock. This was not considered desirable on account of the loss of particles through sliming that inevitably occurs when this course is pursued. This specimen, weighing 55°2 grammes, was then powdered up and the whole of it sent to Messrs. J. and H. 8. Pattinson of Newcastle for analysis. The other specimen was from Boirdni in the Ganj4m district. It shows abundance of a light brown manganiferous garnet scattered through a matrix of opal in which are abundant remains of orthoclase felspar up to -~; inchlong. The opal is of greyish to greenish colour and translucent ; and the apatite, since it is also of a pale greenish colour, is not easily distinguished in the hand-specimen from the opal. Under the microscope it is seen that the opal (with a little chalcedony) has been formed by the replacement of the felspar, and perhaps to a certain small extent by the replacement of the garnet, which is of a pale yellowish colour. The apatite is seen to be much less important in quantity than in the Kotakarra rock. A photomicrograph of this rock is given in fig. 2, Plate 8; it shows orthoclase, garnet, and opal. Some pieces free from black alteration products were selected and their specific gravity deter- mined as before after prolonged boiling. This was found to be 2°65, which must also be a trifle lower than it would have been if determined 1 I am indebted to Mr. K. A. K. Hallowes for this determination. Cuap. XII.] KODURITE SERIES; COMPOSITION. 257 on the powdered rock. The pieces on which the determination was made weighed 16°35 grammes. The whole of them was powdered up and sent for analysis to the same firm of analysts as before. The results of these two analyses are shown below :— Opalized Opalized kodurite kodurite from Kotakarra. from Boirani. A. 233 A. 134 Manganeso protoxide 6 : : : . 10°00 LOT Ferricoxide . 4 ° : - : S . 6°07 : at) Ferrousoxide . “ - : é é : - 0°90 : . 0°64 Alumina . 2 . é - ; ; : 5 11°50 5 . 10°59 Lime c 4 : 5 5 : : - - 11°67 c - 13°87 Magnesia. : c : : : - c B 0°14 - 5 WORKS Potash . : : : : - : . : 0°01 - . 4°00 Soda 0 ‘ ; 5 “ ce . . : 0°18 ‘ 5 O83 Combined silica : : 5 5 “ - ; 35°50 , - o2 20 Free silica : : - j . * : : 18°65 2 . 28°35 Phosphoric oxide. ° : : 5 : 5 1°60 J le: Cupric oxide . . . . : - 5 5 0°02 : . trace Titanic oxide . = 5 5 c : 5 ; 0°32 . a Wwe Chlorine . 3 c C 5 A 2 5 5 trace 5 . trace Combined water A A 5 A : : 3B} ° - L720 Moistureat100°C . : 0 : ty : 2°30 ; » ak30 100 °19 100°19 Manganese : “ c A é . ° - 1b c > 0-83 Tron : . ° é 5 6 - - . 4°95 0 . 3 8 Silica(total) . é > : : 2 S . 54°15 : , 60°66 Phosphorus . . 5 : : - : 0°70 - . 0°54 As the free silica in these rocks is present in the form of opal it is obvious that a portion of it has probably been returned as combined silica. This is confirmed when it is attempted to recalculate these analyses into terms of the mineralogical composition of the rock. In the first rock, since the alkalies present are so small in amount, I have put them aside as impurities, although it would probably be more correct to convert them into corresponding amounts of felspar. In the Boirani rock, however, the potash present is considerable, and in this case 258 MANGANESE DEPOSITS OF INDIA; GEOLOGY. [ Part II: I have converted the alkalies into orthoclase and albite. The mineral composition of these two rocks works out as follows :— Kotakarra rock. Boirani rock. A.233 A.134 Apatite. ; : 3°70 Apatite. : : 2°87 K20 , - § : 0°01 Orthoclase :— K20 4°00 AkO3 4°33 SiO2 15°38 23°71 . - 231 Na20 5 ; F : 0°18 Albite :-— Na20 0°36 Al203 0°59 SiOg 2°10 3°05 3°05 Manganese-garnet :— Manganese-garnet :-— MnO 10°00 MnO 1°07 FeO 4°51 FeO 0°86 CaO 9°57 CaO 12°24 MgO 014 MsO — 026 Al2zO3 11°50 Al203 5°67 Fe203 2°10 Fe203 4°55 Si02 22°76 SiOe2 15°22 60°58 : 60°58 39 87 39°87 Opal :-— Opal :— SiOz 31°39 SiOz 27°90 H20 ies H20 1°26 BP TPs. - 32°72 29°10 . : 29°10 TiOg 0°32 TiO2 0°27 CuO ‘ : 5 , 0°02 CuO : : . 5 trace Moisture . : : : 2°30 Moisture . 5 ~ : 1°30 Surplus oxygen . : - 0°36 Surplus oxygen. - - 0°02 100 °19 100°19 From each of the above analyses we can extract an analysis of the manganese-garnet by multiplying each of the constituents of the garnets by a3 in the case of the Kotakarra rock and by gys7 in the case of the 6058 in Boiréni rock. The results obtained are as follows :— The Kotakarra The Boirani garnet. garnet. MuO . “ : A - = 16°50 - : : E - « 2:68 FeO ; F 5 F 7°45 3 5 : é Pe 3) 3) CaQ-. =. = ; E F 15°80 ; 2 F : < . 30°7D MgO i O524 CuO A 5 = - 0°02 F : 2 . trace 100 °00 100 °00 Specific gravity of original rock , 3°23 : ° . . 2:92 1 The apatite is lower in this analysis, than it would have been on a large sample of the rock ; for the apatite is arranged in bands in the rock, and the apatite bands were scarce in the specimen analysed. Cuap, XII] KODURITE SERIES : COMPOSITION. 261 The figures showing the original specific gravity of the rocks were calculated from the mineral composition of the rocks given above. It is, of course, easy to turn these original mineralogical analyses into the original chemical analyses of the rocks, the results being as follows :— Kotakarra Boirani kodurite. kodurite. SiO2g 2 -, - 47°45 + ; - SO 100 Al203 - - é . 18 “00 » - - welGEsk Fe203.—=Ci«zs 5 ; Fs 1°91 : : = see seit FeO ‘ . ‘ 5 4°10 - A 5 - 0°79 MnO P : A A 9°08 . . 5 - 0°98 CaO 2 z = 5 10°37 - - . 12°54 MgO 5 A : . 0°13 , : ; 5 0':22 K20 é A - 3 6°97 : 5 C O75 Na20 Z ‘i 5 * (4) 0 °33(1) TiOg “ Pr) 5 fs 0°29 = . 7 - 0°24 CuO ‘ ¢ c FA 0°02 - a A . trace P205 : - 5 - 1°42 ‘ : ‘ . iW CaF2(2) . - ; P 0°26 A ; . op LOZ 100 *00 100 00 Assuming these reconstructed analyses to be approximations to the truth it becomes at once evident that it is very difficult to regard the rocks to which they correspond as anything else than of igneous origin. The difference between these rocks and the metamorphic rocks of the gondite series is at once seen by comparing these analyses with that of a piece of typical gondite shown on page 349. 1There is probably a small percentage of soda replacing a part of the potash in the Kotakarra rock ; whilst in the Boirani rock also a portion of the 9°75 of potash is in all probability replaced by soda, in addition to the 0°33 of soda, which corresponds to that shown in the original analysis. 2 The apatite is assumed to be fluor-apatite, although no fluorine is shown in the analysis, CHAPTER XIII. GEOLOGY —continued. The Kodurite Series—-concluded. Alteration of the series and the formation of manganese-ores—Depth to which the ores extend. The Alteration of the Kodurite Series and the Formation of the Manganese-ores. Of the various localities that I visited, the Kodur Mines (Nos. | to 5), Perapi (No. 7), Garbhaém (No. 11), Kotakarra (No. 12), Avagudem, (No. 14), and Ramabhadrapuram (No. 2"), showed the felspathic members of the kodurite series, with, at Kodur and Perapi, the manganiferous pyroxenites free from felspar. At Taduru (No. 21) and Chintelavalsa (No. 22), however, not a trace of felspar was to be seen in any of the manganese-bearing rocks, which are practically all manganese-pyroxenites. As these manganese-pyroxenites, except at the outcrops, seem to be perfectly fresh, no manganese-ores of any value are to be found at these two localities. But at all the other localities named above, namely those where the felspathic members exist, all the rocks of the kodurite series have been subjected to intense chemical action resulting in their partial or complete alteration. This chemical action has been so widespread that it is practically impossible to find in any of these mines a single piece of any of the rocks of this series that has not had at least one of its constituents attacked. The consequence is that, as noted in the previous chapter, it is only possible to deduce the original composition of the rocks of this series by observing the constituents that have escaped alteration in different parts of the workings and so deter- mining the particular mineral that each constituent of the altered rocks represents. Moreover, it is frequently possible to find the fresh form of any given mineral passing into its altered form. To follow out the chemical changes that have taken place it is necessary to know the chemical composition of each constituent mineral of the series. They ere as follows :— Quartz : ; : : : SiOg . Potash-felspar 1 . : ; ; K20. Al2O3. 6Si02 Apatite g : 3 : : 3Ca3P208.CaF2 Spandite2 . : : ‘ ; 3(Ca,Mn)O.(Al,Fe)203. 38i02 Rhodonite . . A MnSi03 Other manganese pyroxenes : Composition not determined’ 1 ASacmake d to be orthoclase. 2 With small quantities of MgO and a very small amount of BaO Cuap. XIII.) KODURITE SERIES : ALTERATION. 263 As rhodonite does not occur to any considerable extent in the deposits where economically valuable ore-bodies occur, it need not be taken into account. Further, the fact that the composition of the other manganese-pyroxenes has been left undetermined does not matter; for these constituents, although more abundant than rhodonite, are not sufficiently abundant in the majority of deposits to have given rise to any considerable proportion of the ore. The changes that have affected the other minerals, as judged by the products of alteration left in the deposits, are, however, well worth consideration. The quartz seems to a large extent to have escaped alteration, for it The replacement of 18 to be detected as visible grains in much of the quartz. lithomarge. But it may to a certain extent have been dissolved and re-deposited as chert by the carbonated alkaline waters that decomposed the felspars (see below). It has also often been metasomatically replaced by manganese-ore (see fig, 4, Plate 13). Almost everywhere the felspar seems to have been converted into The alteration of the Uthomarges. These are often stained yellow, brown, felspar. lavender, etc., owing to impregnation with oxides of iron ; but they are sometimes pure white. One such white lithomarge was analysed by Mr. J. ©. Brown (see page 1060), and, except fora little mechanically mixed quartz, was found to have the composition of pure kaolin ; and probably all these lithomarges would be round on analysis to approach closely to this mineral, any deviations from the composition of kaolin being explicable as due to the presence of oxides of iron and manganese and of particles of quartz. The alteration of the felspar may be supposed to have been produced by the action of carbonated waters thus :— Ka20. AleGC3.6Si02 + CO2 + 2H20 = 2H20. Ale03.2S8i02 + KeCO3 + 48102. Orthoclase. Kaolin. If these carbonated waters were not originally alkaline then they speedily became so by taking into solution the potash of the felspar. As is well! known carbonated waters exert a powerful solvent action on silica, especially when it is in the gelatinous form in which it is so often liberated on the decomposition of silicates ; these waters hence doubtless took inty solution the silica released from the felspar in accordance with the above The formation of equation. In spots where the conditions were chert and opal. favourable this silica was often deposited in the eryptocrystalline or colloidal condition as chert or opal respectively ; 264 MANGANESE DEPOSITS OF INDIA: GEOLOGY, [ Part II: apparently much more frequently as the former, however, for large masses of chert, usually brown in colour, are to be found in almost every quarry (see pages 1065, 1079, 1089, for examples). The re-deposition of the silica seems often to have taken place by the metasomatic replacement of some or all of the constituents of portions of the kodurite mass. Where chert has been formed the replacement seems usually to have been com- plete ; but where opal has been formed the replacement has been as a rule only partial, some chalcedony being usually formed as well. Exam- ple of replacement by opal occur at Kodur (see fig. 1, Plate 8; fresh spandite in a matrix of opal and chalcedony formed by the replacement of felspar, and of black manganese-ore probably representing original pyroxene), at Kotakarra (page 256, felspar replaced, garnet and apatite unaltered), and at Boirdni (page 256, garnets fresh, felspar partly fresh Potash removed in 2@0d partly replaced; see fig. 2, Plate 8). The solution as carbonate. potassium carbonate formed from the potash of the felspar must have been completely removed by the waters. Though many of the microscope slides of the rocks from various Alteration and re. localities show that apatite suffers replacement placement of apatite. by manganese oxide during the formation of the manganese-ores, yet no evidence has been found to show what becomes of the phosphorus and fluorine thus removed. From the evidence of the microscope there is no doubt that in many cases the phosphorus of the manganese-ores is at least partly due to the presence of residual apatite that has escaped replacement. But there is no evidence that this is always the case, and it is possible that some of the phosphoric oxide that must be set free when apatite is replaced, is taken up by the manganese-ore as oxide; or this oxide may be removed in solution and deposited in the ores at another spot. Apatite is, however, often a very abundant constituent of kodurite, sometimes forming as much as 10 to 30 per cent. of the rock. The manganese-ores of this area are, it is true, very phosphoric from the commercial point of view, since they range in phosphorus contents from about 0°25 to 0°50 per cent. But this, if present as fluorapatite, would correspond to a proportion of only 1-35 to 2°71 per cent. of apatite; whilst even 1 per cent. of phosphorus only means 5°42 per cent. of apatite. Hence it seems probable that all the phosphorus in the original apatite has not remained in the ores, either as apatite or oxide. Some of it must have been removed in solution together with the potassium carbonate derived from the felspar. The fate of the lime of the apatite must have been the same as 1 Le | a: - , - a6. 7 h ae i : = =e °6 a te . = = ? 4 » ie re * s » o@ i MG 32h @ LAS ¢ feu T PORT 3) : ; io 2 7 Sod ee NiO Gity PEP, DOG hie’ Hii | ana) = sd - iy k 4 i ' “ eo bi) (7 oN ' i Mary ed) w Deus 7 Te a? Bin, 0 Sete arnay put ns : sah & ie ae r Te ¥ wy 7 ape x. = - 7 *, aioe Py j ‘ : -$i tt ‘ : * | oe ae . ae ee . _ han ~ 7 ~~ . ae : : vw! ona , As : " : al sa ve _ ¢ = > — £ Wye . oe ae bas = : in «' io Se") : : Ris ws sy “7 eF : rt —_ by u. _ y ) : 2 a 7 Ae = ~“ 1 - , o - . : J oe - = re) EXPLANATION OF PLATE 8s. PHOTOMICROGRAPHS. Isa, 1,—The grey mineral showing high relief is the spandite. The remainder is opal with black stains of manganese oxide and clear central patches of chalcedony. Fia, 2._-Comparatively fresh orthoclase is seen in the lower part of the photo- graph, and garnet in a matrix of opal with yellow stains of iron in the upper part. Fic. 3,—-The apatite is white. The remainder is spandite with secondary man- ganese oxide. ia, 4,—Spandite—white ; psilomelane—black. GHOLOGICAL SORVEY OF INDTA. Memoirs, Vol. XXXVII, PI.8 Fig. 1.—X 16. Fig. 2.—-x 16. Opalized kodurite. Opalized kodurite with some orthoclase Kodur, Vizagapatam district. remaining. solranl, Ganjam district, Madras. .. L. Fermor, Photomicrograph. Bemrose, Collo., Derby. Fig. 3.— X 16. Fig. 4.—X 23. Apatite-spandite-rock. Spandite (manganese-garnet), in psilomelane. Kodur. Ramabhadrapuram, Vizagapatam district. Cuap. XIII] KODURITE SERIES ; ALTERATION, 265 that of the lime of the garnet, namely to be carried away as bicarbonate.’ The manganese-garnet or spandite seems to be the most stable minera] Replacement of the 1 kodurite and many examples can be found of spandite. unaltered garnets in a matrix of partly or completely kaolinized felspar. When kodurite suffers replacement the garnet is usually the last mineral to be replaced, whilst it often escapes altogether, as in the rocks from Kotakarra and Boirdni (see fig. 2, Plate 8), where the felspar has been replaced by opal. When the replacement is effected by manganiferous solutions the felspar and apatite are often removed leaving perfectly fresh garnets in a matrix of psilomelane. Such garnet-studded psilomelane is especially common at Garbham and Ramabhadrapuram (fig. 4, Plate 8). From this photomicrograph it will be seen, however, that the garnet is also beginning to be replaced by the psilomelane, veinlets of which are seen traversing the garnet. But the garnet itself also often suffers alteration, and although the man- ganese-pyroxenes have in some places provided a certain proportion of the manganese required for the formation of the manganese-ores, yet the major portion of the manganese has been derived from the garnets. When kodurite is altered, the resultant rock is often crumbly lithomarge Alteration of span- Containing abundant scattered garnets and apatites. dite. The alteration has, however, more often than not proceeded much further. The apatite has been completely removed whilst the garnet is still represented by little ochreous spots suggesting that the iron oxide is the last constituent of the garnet to be removed. The garnet from Garbham analysed by Mr. J. C. Brown contains the following constituents (for complete analysis, see page 167) :— Per cent. Si02 . a * 5 é 2 A 5 z Fi 35 “24 Fe203 . 5 : 7 i . F Z : : 23°90 AleOz3 . 3 x 5 3 . : , 2 : 6°48 MinO % 5 y ‘ A : ; P ; f 16°37 153(0) ‘ : s ‘ . 2 ‘ 4 s 0°18 CaO “ 5 ; 3 ; $ 3 r 3 : 15°20 MgO . k ; x : : . E ‘ 5 2°04 99°41 The composition deduced for the garnet in the kodurite of Kotakarra is given on page 258. 1Both apatite and Cag (PO4)2 are known to be distinctly soluble in water containing CO2 in solution. See A.M. Comey’s ‘Dictionary of Chemical Solubilities Inorganic,’ page 298, (1896). Tl ¢ 266 MANGANESE DEPOSITS OF INDIA: GEOLOGY, [Part II: Now the alteration of the garnet must have been effected by the same agency, namely, carbonated water, as converted the orthoclase into kaolin. The action of such waters on a garnet of the above composition would be to remove the manganese and calcium, and the little magnesium, as bicarbonates, and to leave behind the alumina as kaolin, mixed with ferric oxide, the two forming the ochreous spots referred to above. The silica not required for the formation of the kaolin must, as in the case of the felspar, have been removed in solution and may also have contri- buted to the formation of the chert. It is shown on page 167 that a small portion of the iron oxide of the garnet was probably in the ferrous condi- tion. This portion, 2°29 per cent. would also be removed as bicarbonate. These manganiferous solutions circulated through the mass of kodurite rocks until perhaps they had taken up as much of the bicarbonates of manganese and calcium as the carbon dioxide in the solution would allow of. On now coming in contact with either fresh or decomposing kodurite they would no longer take up any more manganese. Now an examination of such a deposit as Kodur shows that although Formation of man- portions of the mass of rocks exposed are undergoing apaag ar vas alteration on the lines explained above, yet there rocks. are other portions of the deposit in which the rocks are not being to any great extent kaolinized, but are instead suffering replacement by manganese-ore. The rocks that suffer this replacement may be divided into two groups, those, such as the quartz-felspar-rocks, that contain no manganese-bearing minerals, and those, such as kodurite, that contain a manganese silicate. Iam of opinion that it is the saturated manganiferous solutions referred to above that cause the replacement of these rocks. Let us deal first with the non-manganiferous rocks. It is evident, Replacement of the both from an examination of the rocks im situ and lie Te ie from a study of specimens of the rocks macro- scopically and under the microscope, that the whole mass of rock is under- going a more or less complete replacement with the production of masses of manganese-ore, the purity of which depends on the extent to which this replacement has taken place. In some cases the rock to suffer replacement is the more or less decomposed quartz-felspar-rock or felspar-rock, the partial kaolinization of the rock having been no doubt effected by non-manganiferous solutions before the advent of the mangan- iferous solutions, The manganese-ore that first appears in this must Cuap, XITI.] KODURITE SERIES ; ALTERATION, 267 gradually grow by the continual segregation from the circulating mangan- iferous solutions of fresh quantities of manganese oxide; this being by preference deposited round the edges of, or in, the patches of manganese- ore already formed, rather than in parts of the rock in which manganese oxide has not yet been deposited. As a result of this irregular replace- ment many exposures are seen showing more or less kaolinized white quartz-felspar-rock or felspar-rock, with patches often many feet across that are black in colour due to a network of black manganese oxide, deposited along the boundaries of the grains of quartz and felspar, and in part replacing them. Here and there the replacement is complete, so that these black areas often contain irregularly scattered nodules and patches of merchantable manganese-ore, usually pyrolusite, but sometimes psilomelane. But the quantity of cre so formed is not usually sufficient to make it worth while to extract it, unless it is necessary to quarry the mass of rock in which it occurs as a part of the dead-wurk of the mine. Examples of this irregular replacement of the felspathic rocks are given in figures 85 and 86 on pages 1085 and 1086; and in fig. 4, Plate 13. It is difficult to explain this and many other cases of replacement Minerals replaced by Of one mineral by another in terms of chemical manganese-ore. equations. But the examination of many hundreds of microscope-sections, hand-specimens, and exposures on outcrops and in mines, has convinced me that it is possible for a solution containing manganese salts to replace with manganese oxide almost any mineral. Amongst the minerals I have found thus replaced are iron-ores (hematite and limonite), quartz, calcite, felspar (orthoclase, microcline, and plagio- clase), various micas, garnets, pyroxenes, and amphiboles, and apatite, In the particular case of the replacement of orthoclase by manganese oxide noticed above, it is possible, assuming the manganese to be in solution as bicarbonate—as it would be, in accordance with what has been written on page 266, had it suffered no alteration in the meantime—, to explain the interchange by the greater affinity of carbon dioxide for potassium oxide than for manganese oxide. This interchange might then be expressed by the following equation :— MnH2(CO3)2 + 2(K20. Al203.6Si02) + O2=2K2CO3 + 2Al203 + 12Si02 + HeMnO3. Orthoclase. In the presence of oxygen, probably present in solution, either in the manganiferous waters, or in water occupying the interspaces between the grains of mineral in the rock attacked, or less probably mechanically 1 Ons 268 MANGANESE DEPOSITS OF INDIA: GEOLOGY, [ Parr II: retained in the gaseous condition in these same interspaces, the manganese would be deposited as one of the hydrated more highly oxidized forms, such as HpMnOs. If originally deposited as MnO or Mn(OH), it would speedily be changed to a more highly oxidized form. The silica would be removed in solution in the alkaline carbonate. According to the well-known fact that alkaline carbonates precipitate aluminium hydroxide from solutions of aluminium salts, the alumina in the above The removal of equation should be left behind with the precipitated alumina. oxide of manganese, probably in the form of kaolin in combination with a certain proportion of the silica set free, The manganese-ores thus formed in these felspathic rocks do frequently contain a certain amount of alumina, but nothing like the quantity they should contain in accordance with the equation. It seems neces- sary, therefore, to suppose that under the conditions of temperature, pressure, and concentration, in which this replacement took place a large portion of the alumina was removed in solution in spite of the presence of carbonates. In this connection it must be remembered that all the chemical changes to which reference is being made in this section of this Memoir were probably effected by very dilute solutions and that a very slight solubility of the alumina would suffice for its removal, When the saturated manganiferous solutions hypothecated above Replacement of the come in contact with rocks containing manganese manganiferous varie . ere . fed. minerals, they can no longer assist in the breaking up of these rocks by dissolving further quantities of manganese and calcium from the garnet. On the other hand they probably begin to rid themselves of their burden of manganese by a more or less complete replacement by manganese oxide of the rock with which they come in contact. If the rock is kodurite, the commonest of the manganese- silicate-rocks, the felspar is replaced in the same way asin the case of the felspathic rocks outlined above. Sometimes the replacement seems to stop here and the product is manganese-ore, generally psilomelane, studded with bright orange-red or orange-brown garnets, as at Garbham and Raémabhadrapuram. As the garnet itself contains manganese there is probably less tendency on the part of the manganiferous solutions to replace it by manganese oxide. Often, however, the replacement seems to go further than the substitution of the felspar and apatite and the yarnet itself suffers replacement. As the solution effecting the change is depositing manganese oxide in the place of every constituent of the Cuap. XIII.) KODURITE SERIES ; ALTERATION, 269 rock that undergoes replacement, when the garnet is attacked the mangan- ese it contains must be left behind with the manganese oxide deposited from the attacking solution. So that the resultant manganese-ore consists of the original manganese contained in the rock together with that brought in by the replacing solutions. Not only can manganese-ores be formed by replacement in the way oo described above, but they can be formed by ese-ores by alteration the alteration im situ of the very highly man- in situ of manganese- ganiferous varieties of the kodurite _ series. Sa This was to be well seen at the time of my visit to the Kodur deposit. In the north-east corner of the mine at the point A in fig. 82 on page 1060 there was exposed a mass of spandite-rock in every stage of alteration into manganese-ore, which was being actively quarried. The final product of the alteration is a vesicular psilomelane with numerous vesicles averaging about ,', to + inch in diameter. Some of these vesicles are found to contain water when freshly broken open, whilst others contain a brownish black powder, and some are filled with shining black braunite usually traversed by very thin veinlets of psilomelane. Since a common type of ore in this mine is massive grey psilomelane with small specks and patches of braunite, it seems probable to me that the vesicular ore mentioned above must be an intermediate stage between the garnet-rock and this massive ore, and that later the vesicles have become filled with braunite by percolating solutions of which we have evidence in the water contained in the cavities of the ore. I have alluded to this ore as having been formed by the decomposition of the spandite-rock in situ ; but it is evident that, if this rock were decomposed and most of its constituents removed in solution except the manganese oxides and iron, the residue would be a porous mass of oxides and not solid manganese-ore. Hence it is necessary to suppose that a further portion of manganese was brought in in solution and added to that derived from the decomposition of the rock in situ. The question now arises as to whether manganese oxide was brought in after the span- dite-rock had been decomposed with removal of most of its constituents except the oxides of manganese and iron ; or whether the decomposition of the garnet and removal of certain of its constituents were effected by the same solutions as brought in the further supply of manganese oxide. For two reasons it is unlikely that the former is the case. In the first place, as carbonated alkaline solutions are supposed to account for the changes noticed in other parts of the deposit, it is necessary to suppose 270 MANGANESE DEPOSITS OF INDIA: GEOLOGY, [Parr II: that they also produced the decomposition of the spandite-rock. Had this decomposition taken place without the deposition of manganese brought in solution by the incoming waters, the results of the action would probably have been the same as have already been described as taking place when kodurite is attacked by these solutions, namely, the solution of the manganese and calcium as bicarbonates, leaving behind little else but the ferric oxide and any alumina in the garnet as kaolin, In the second place the rocks in this part of the mine show every stage of alteration from the comparatively fresh spandite-rock to good manganese- ore without any signs of the porous rock that would be formed if the decomposition oi the garnet-rock took place separately from the intro- duction of manganese oxide from elsewhere. For these two reasons it is necessary to suppose that the solutions that effected the decompo- sition of the spandite-rock also deposited the manganese oxide brought in from outside. The solutions to produce this combined decomposition and deposition would be the alkaline carbonate solutions saturated with manganese bicarbonates. The reaction can be supposed to take place somewhat on the lines of the following equation :— 2[3(Ca,Mn)O.(Fe, Al)203. 38i02]* + 3MnHa(CO3)2 + 302 + 6H20 Spandite. = 6(MnOz. H20) + 2(Fe, Al)203 + 3CaH2(CO3)2 + 6Si0e. It will be seen that I have introduced oxygen into the above equation, Alteration took place 1¢ is not of course known whether the manganese under oxidizing condi- was originally deposited in the protoxide condition as and subsequently oxidized, or whether it was originally deposited in the more highly oxidized condition. In whichever condition it was deposited the oxide was probably hydrated, and in so far as it is now free from water has since become dehydrated. I think, however, that it was probably originally deposited in the higher state of oxidation ; in the first place because I think the formation is still going on to a certain extent, as for example at Kodur, obviously sufficiently near the surface to be within the range of oxidizing influences; and in the second case because there seems to be no sign of any mineral, such as manganosite (MnO), pyrochroite (MnO.H,0), or rhodochrosite (MnCOs), in the lower state of oxidation, although these might have been formed and since entirely raised to the higher state of oxidation due to subsequent prolonged subjection to the influence of waters containing * Ca and Mn assumed to be present in equal molecular proportions. Cuap, XIII] KODURITE SERIES ; ALTERATION. 271 dissolved oxygen. It is interesting to notice that this deduction that the ores were formed under oxidizing conditions, meaning that they were formed comparatively near the surface, agrees with the conclusion, discussed later on, that kaolinization takes place comparatively near the surface. The calcium bicarbonate and silica shown in the foregoing equation would pass away in solution leaving a mixture of hydrated oxide of manganese with ferric oxide. The analysis of the Garbhdm ! spandite, which is very similar to that found in the part of the Kodur mine to which reference is made on The removal of alu. Page 269 shows 6-52 per cent. of AlyOg, whilst mina. those of three pieces of manganese-ore, A.334, A.336, and A.338, from this same part of the Kodur mine show 1-38 to 6°84 per cent. of Al »O3, the mean value being 3-71 per cent. Now, owing to the removal of silica, as shown in the foregoing equation, we should have expected a small increase in the percentage of Al,Os, rather than a decided decrease. As it might be thought that the decrease shown above is fortuitous, and dependent on the specimens chosen for analysis, it is to be noticed that the calculated analysis of the Kotakarra garnet (page 258) shows 18-98 per cent. of Al,O3, and that the mean percentage of Al,O, in 10 Vizagapatam ores of which the analyses are scattered through this Memoir is 2-50, the range being from 0:27 to 6-84. Some of the ores thus analysed may have been formed entirely by replacement; but in any case the point illustrated is that in whatever way the ores are formed there is a tendency for a disappearance of AlyO3. Hence the equation given above is not strictly true, because a portion of the AlyOs is removed, probably by the same solution as decomposed the rock and deposited the manganese oxide. (Compare page 268). We can regard the ores formed in this part of the Kodur mine as the combined product of the alteration of spandite-rock in situ and of the deposition of manganese oxide brought in from elsewhere ; the deposition of this manganese oxide being probably somewhat of the nature of a replacement, in which the manganese contained in the solution attacking the garnet is deposited in the place of the constituents being dissolved. 1 It is a pity that no analysis of Kodur garnet is available. The Garbham one was chosen because it happened to be easier to pick clean; but it looked exactly the same as the Kodur garnet. I have compared this ana:ysis with those of the Kodur manganese-ores noticed above, because the Kodur ores are ones formed in situ from the gainet-rock ; whilst this does not apply to the Garbham ores analysed. 272 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part Il: From what has been written above it is evident that the ores of the The ores formed in Vizagapatam district can be divided into three three ways. main divisions :— 1. Those formed by the replacement of rocks, such as quartz-felspar- rock, not originally containing manganese. In this case all the mangan- ese is of external origin. 2. Those formed by the replacement of rocks, such as kodurite, that contain a fair amount of manganese silicate, the manganese of the latter being added to that of the attacking solutions. In this case the larger proportion of the manganese is of external origin. 3. Those formed by the decomposition in situ of rocks composed almost entirely of manganese silicates, to the manganese of which a further portion, brought by the attacking solutions, is added. In this case about half of the manganese is of external origin. It is difficult to say what proportion of the ores of this district have been formed by each method. In the Kodur mine ores of groups 2 and 3 probably predominate; whilst at Garbham a considerable proportion of the ore has probably been formed by method 1, although ores formed by 2 and 3 still predominate. The ores formed by the different methods are not exactly the same and are shown below :— 1. Pyrolusite and psilomelane. 2. Psilomelane with some braunite. 3. Psilomelane with braunite as, specks and patches. In the equation given on page 270 it is assumed that all the ferric Ferric oxide in the OXide remains in the manganese-ore. The spandite ore. from Garbhédm, of which an analysis is given on page 168, shows 21°28 per cent. of Fe O3, whilst the percentages of Fe,03 in the three ores from the part of Kodur mentioned on page 269 are 5°86, 6°57, and 13°14, with a mean of 8°52. This seems to indicate a removal of iron in solution. That this is probably not the case is indi- cated by a consideration of a larger number cf analyses. Thus the Kotakarra garnet contains only 3°47 per cent, of Fe203, so that the mean of the two garnets is 12°37 per cent.; whilst the mean of the Fe Os in the 22 analyses of samples and pieces of manganese-ore from this district is 13°57 per cent.1 1 See foot-note to page 271. , Cuap. XIII.) BRAZILIAN DEPOSITS. 273 An interesting feature of the manganese-ores of the Vizagapatam district is the baryta found in the 22 analyses referred to above. The amount of this constituent ranges from 0°03 to 9°53 per cent., the mean value being 2°03 per cent. Now according to the analysis of the sample of opalized kodurite, No, 233, given on page 257, and carried out by Messrs. J. and H. S. Pattinson, kodurite is to be supposed to contain either no barium at all, or such a small quantity that it cannot be estimated. Mr. J. Coggin Brown, however, found 0°18 per cent. of BaO in the specimen of spandite that he analysed, and possibly all spandite if carefully tested would be found to contain a trace or small quantity of this constituent. Since the amount of BaO in the original rocks is so small, the comparatively large quantity found in the ores cannot be simply residual, 7.e,, have been left behind with the oxides of manganese and iron and a certain proportion of the Al,O3, when the garnets suffered decomposition. It is necessary to suppose that this was one of the constituents that went into solution, probably as bicarbonate; it must have been thus concentrated and later deposited during the formation of the manga- nese-ores. Unless, however, a much larger proportion of manganese passed into solution than was ultimately deposited as manganese-ore, it is difficult to explain the great increase of the BaO relative to the manganese oxides. If the supposition put forward in the former part of the previous sentence be thought to be unlikely, then it is necessary to suppose that the waters that originally attacked the masses of kodurite rocks brought in the barium oxide as a part of their burden, having obtained it from a source different to the rocks of the kodurite series. Baryta in the ores. It will be interesting to compare the, Indian manganese-ore deposits Comparison with the Of the kodurite series with those of the Queluz Brazilian deposits. district, State of Minas Geraes, Brazil, the only ones, as far as I can discover, that bear any resemblance to those of Vizagapatam. Dr. Orville A. Derby!, who has studied the Brazilian deposits, ascribes their formation in many cases to the decom- position and leaching of basic manganiferous rocks of which the most important mineral is manganese-garnet (spessartite). These masses of manganiferous rock often occur as dyke-like masses and are considered to be the result of magmatic segregation from a basic magma of dioritic, gabbroitic or noritic type, now represented by the very decomposed, 1 Amer. Jour. Sct. XII, pp. 18-32, (1901). 274 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [ Part IL: and sometimes sheared, clay-like ‘ country ’ in which the manganese-ore bodies occur. It will be seen that there is a general analogy between this theory and that which is supposed to explain the formation and structure of the Vizagapatam deposits of India’ The analogy, however, only applies to the processes, 7.e., the magmatic segregation of the manganiferous rocks from a molten magma, with subsequent chemical changes producing the ore-bodies from the manganiferous-rocks and the clays (or lithomarges) from the less manganiferous ‘ country —and not to the actual rocks con- cerned. For in Brazil the residual rock, left after the segregation from the magma of the manganiferous-rocks, was of basic character, while in Vizagapatam it was either a felspar or felspar-quartz-rock, 7.e., a more acid rock. The product of segregation in Brazil, moreover, was essen- tially a manganese-garnet rock sometimes containing an amphibolic (or perhaps pyroxenic) or micaceous mineral, and at other times instead of these latter free (original) manganese-oxide (? polianite) with ilmenite and rutile as accessories and a very small quantity of apatite, while both quartz and graphite, supposed to be subsequent introductions, also occur. This type of rock has been denominated gueluziie by Derby. As shown in Chapter XII, kodurite, the typical product of segregation in the Vizaga- patam area, is a considerably different rock of which the three chief constituents, apatite, spandite, and felspar, are all equally important. The Depth to which the Manganese-ores extend. There remains one very interesting question to discuss in connec- tion with the alteration of the masses of kodurite rocks, namely, the depth at which this alteration took place. For on this depends the depth to which the bodies of manganese-ore may be expected to extend. This problem is to be solved by a consideration of the depths at which the processes of kaolinization and oxidation occur. Let us deal first with kaolinization. Two different reagents have been invoked to explain this process. These are water contain- ing carbon dioxide in solution, and water contain- ing sulphuric acid. Waldemar Lindgren! says :— Kaolinization. ‘ Apparently the pure aluminic silicate cannot be formed when the generating waters contain much carbon dioxide or alkaline carbonates. But it does form ‘Metasomatic Processes in Fissure-Veins ’, Trans. Amer. Inst. Min. Eng., XXX, p- 658, (1900). CHapP, XIII] KODURITE SERIES : KAOLINIZATION. 275 under the influence of some waters containing a small amount of these reagents, and also in the presence of sulphuric acid, which, as is well known, rapidly attacks the feldspars.’ From the results of the reaction of the water on the rock concerned it can be said which of these two agents was contained in the waters. With carbon dioxide, orthoclase felspar is decomposed in accordance with the following equation :— 3K2Al2Sig Oy +6H20 + 3CO2= 3(2H20.Al203.28i02) +3 KeCO3 + 12Si02. Orthoclase. Kaolin, The alumina being insoluble in the presence of carbonates is left behind as kaolin, while the silica being soluble, is carried away in solution. With regard to water containing sulphuric acid Lindgren says ! :— ‘Silica is practically insoluble in solutions containing sulphates and chlorides, hydrogen sulphide and free sulphuric acid. Under these conditions, aluminum silicates are dissolved and sulphates or chlorides of aluminum are formed, with simultaneous separation of silica.’ Since, in the Vizagapatam manganese-ore deposits, a large portion of the silica has evidently been taken into solution and the alumina left behind as kaolin, the alteration of the rocks of the kodurite series has been considered on the preceding pages as due to the action of waters con- taining carbon dioxide in solution. Vogt, writing on the same subject , says that the view held long ago by Forchhammer (1835) and Bischoff (1855), that kaolinization is due to the attack of water carrying carbon dioxide, must be the cor- rect one for the following reasons :— ‘ (1) kaolinization is in many cases a surface process, afiected by the weak carbonic-acid solutions of surface-waters ; (2) at somewhat greater depths, the feldspars of the rocks are often converted by similarly weak carbonic-acid waters into kaolin, sericite, etc., as well as calcite.’ On a later page 3 he mentions the three processes that are due to the action of waters containing carbon dioxide, or carbonates of alkalies, or alkaline earths, in variable proportions. These three processes are kaolinization, sericitization, and carbonatization :— ‘ In kaolinization, the waters carry so much carbonic acid that the alkaline and earthy carbonates are nearly or wholly removed, together with the dissolved silica. In sericitization and carbonatization, on the contrary, there is a deposit of potassium silicate or calcium carbonate.’ 1 *‘Metasomatic Processes in Fissure-Veins,’ Trans, Amer. Inst. Min. Eng., XXX, p.664, (1900). 2 ‘Problems in the Geology of Ore-Deposits,’ Trans, Amer. Inst. Min, Eng., XX XI, p.150, (1901). 3 Ibid., p. 157. 276 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part II: Quite recently, Lindgren! has made the following remarks on the formation of kaolin :— « The hydrothermal origin of large bodies of kaolin has been urged in several recent papers 2, by demonstrating the improbability of the formation of the mineral ona great scale by ordinary weathering and by indicating its connection with mineral deposits. Conceding this, it is nevertheless believed that kaolin is rarely formed by alkaline hot water at any considerable depth below the surface. Instances are multiplying (the occurrences at Cripple Creek among them) in which it can be shown that the kaolin of the upper levels exposed to oxidation changes into sericitie products in depth and that it is easily and abundantly formed by the action of solutions containing free sulphuric acid on sericitized metasomatic rocks and also, though less easily, on ordinary feldspathic rocks.’ Again, as there is no evidence that the felspathic rocks of the kodur- ite series of Vizagapatam have ever passed through the sericitic stage, there is no necessity to consider sulphuric acid as the reagent to which their chemical alteration is due; but rather water containing carbon dioxide, reinforced by the addition of potassium carbonate as soon as some of the orthoclase had been decomposed by the attacking waters. From the foregoing extracts it will be seen that opinions differ as to the amount of carbon dioxide present in the solutions producing kaolinization ; but that it is agreed that kaolin is formed near to the surface rather than at consider- able depths, and that, according to Lindgren, it occurs in the zone of oxidation, giving way to sericite at greater depths. Now let us deal with oxidation. C. R. Van Hise 3 has divided the outer crust of the earth into three zones: an upper zone of fracture, a Tha cSugceeaetee lower zone of flowage, and a middle zone of com- and belt of weather- bined fracture and flowage.4 The zone of fracture is ane that near the surface, and probably continues to a depth of about 3,000 feet. This upper zone of fracture is divided by Van Hise 5 into :— «(1) an upper belt of weathering, and (2) a lower belt of cementation. The belt of weathering extends from the surface to the level of ground-water, and for Oxidation. 1 ‘The Relation of Ore-deposition to Physical Conditions,’ Economie Geology, II, p. 120, (1907). 2 Stutzer, Zeitschrift fiir prakt. Geologic, XIII, pp. 333-336, (1905). 3 ‘Some Principles Controlling the Depositicn of Ores’, Trans. Amer. Inst. Min. Eng., XXX, p. 30, (1900). 4 Van Hise elsewhere considers that the zones of fracture and flowage—divisions of the earth’s crust based on structural considerations—correspond respectively to the zones of katamorphism and anamorphism—divisions of the earth’s crust from the metamorphic point of view. See ‘A Treatise on Metamorphism’, U. 8. Geological Survey, Monograph XLVII, p. 190, (1904).’ 5 ‘Some Principles Controlling the Deposition of Ores’, Drans. Amer. Inst. Min. Eing., XXX, p. 72, (1900). Cuar. XIII.) KODURITE SERIES ; DEPTH OF ORES, 277 a variable distance into the sea of underground water. The belt of cementation extends from the bottom of the belt of weathering to the bottom of the belt of fracture.’ The distinction between these two belts is summed up by Van Hise ! as follows :— ‘The belt of weathering is characterized by disintegration and decompositicn, carbonation, hydration and oxidation, by solution and decrease of volume. The belt of cementation is characterized by cementation and induration, by hydration, by deposition, and by increase of volume.’ The chief constituent dissolved out of the belt of weathering and transferred to the belt of cementation is silica formed during the decom- position of the silicates under the influence of water containing carbon dioxide. . From this it will be seen that the chemical changes, namely, carbon- ation and oxidation, characterizing the manganese-silicate rocks of the Vizagapatam district must have taken place since the rocks of the kodurite series came into the belt of weathering. The depth to which the zone of weathering extends at a particular locality depends on the level of ground-water at that locality. In general the ground-water level follows roughly the inequalities of the earth’s surface. According to Van Hise? :— Ground-water level. «In regions of moderate elevation and moderate irregularities of topography the level of groundwater is usually from 10 feet to 100 feet below the surface. It is especially likely to be near the surface in regions where there is a thick layer of drift or a thick layer of disintegrated rocks. In elevated and irregular regions, and especially those in which the precipitation is rather small, the level of ground- water may be from 100 to 300 feet below the surface. In high, desert regions, and especially limestone regions, the level of groundwater may be from a thousand to several thousand feet below ihe surface.’ In the portion of the Vizagapatam district where the manganese- ore deposits are found, the topography is fairly flat, whilst the rainfall is moderate, namely 40 to 50 inches annually. Hence it is probable that the level of ground-water is fairly near the surface, probably much less than 100 feet below plain level. Hence, if the deposits were formed whilst the ground had its present configuration, we should not expect them to continue to any great depth below the surface before giving way to moderately fresh examples of the kodurite series. In the Kodur mine, however, a depth of some 90 to 100 feet below the level of the adjacent plains has already been reached. Now, although the level of ground-water probably lies higher than the bottom of this pit—considering the large amounts of water that continually enter it and 1 [bid., p. 74. { 2 Tbid., p. 51. . 278 MANGANESE DEPOSITS OF INDIA; GEOLOGY. [Part II: necessitate constant pumping—, yet good ore is found to the very deepest parts of the quarry. Hence it would seem that the present ground-water level is higher than it can have been at the time of formation of the manganese-ores, so that we cannot rely on the present level of ground-water for information as to the depth to which the manganese-ore deposits may be expected to continue. This means that the main mass of the ores was formed in the past, Time of formation between the time when the processes of elevation of ores. and denudation brought the rocks of the kodurite series to the surface and the present. The last serious folding of the Archean rocks of this area was probably contemporaneous with the folding of the Dharwar rocks in other parts of India, which took place somewhere between the deposition of the Dharwars and the rocks of the Purana systems. It is probable that during this folding some of the rocks of the kodurite series were exposed at the surface. Their altera- tion may therefore have commenced in Archean times and continued ever since, except for interruptions when the outcrops of the Archean rocks were covered up by younger formations, such as perhaps the Purdna formations and the Deccan Trap. No doubt denudation has been continuously removing the surface portions of the altered rocks, thus bringing deeper and deeper zones of the rocks nearer the surface and consequently within the influence of the carbonating and oxidizing waters. Now the depth to which this alteration extended in past times depends Depth to which the OD the maximum depth of the ground-water during ores extend. the period in which the masses of kodurite rocks were exposed at the surface. In the absence of any information as to the climatic and topographic conditions of this region, between Archean and historic times, it is not possible to say what wasthis maximum depth of ground-water in past times. Unless, however, this region was ever an arid region of very irregular and elevated topography, it is not likely that the ground-water level ever sank to the extreme depth of 1,000 and more feet characteristic of such regions. Let us assume that it was never at a depth of more than about 500 feet. Now, according to Van Hise, the zone of weathering may extend for some distance below the ground-water level. To allow for this let us put the maximum former extension in depth as 700 feet, Allowing for the denu- dation of an unknown amount of the surface portion of the kodurite rocks since the time when the ground-water level reached this maximum CuaP. XIII.] KODURITE SERIES ; SOURCE OF CO). 279 depth below the surface, we can put the present depth of this former boundary between the belt of weathering and the belt of cement- ation as not more than 500 feet. As it is not probable that the alter- ation of the kodurite rocks accompanied by the formation of oxidized ores continued to any considerable depth below the bottom of the belt of weathering, we can take this figure of 500 feet as being a guess at the maximum depth to which the manganese-ores of this district may be expected to extend. Itis obvious that as the assumptions on which this figure is based are merely guesses, it may happen that the ores con- tinue to a considerably greater depth, or that they do not extend so deep. But in any case they probably extend deeper than it will be profitable to work them, considering the irregular distribution of the ore-bodies through the decomposed masses of lithomargic rock in which they occur. There is one other point worth considering, namely, the source of The sources of the the carbon dioxide that is supposed to have brought carben dioxide. about the alteration of the kodurite rocks. This question of the source of the carbon dioxide that plays such a promi- nent part in the formation of ore-deposits is excellently summed up by Van Hise on page 96 of the paper already cited. Van Hise says :— ‘T have already pointed out two sources for the excess of carbon-dioxide held in the underground waters. Where vegetation is abundant, carbon-dioxide is concentrated in the soil. A large part of this is retained in the belt of weathering by the process of carbonation of the silicates, but another part joins the sea of underground waters. Another source for the carbon-dioxide is that liberated from cavities within rocks. It is well known that in many rocks a large amount of carbon-dioxide is included in innumerable microscopic cavities. When such rocks are complexly deformed in the zone of fracture, the fractures must intersect many of these cavities, and thus liberate the carbon-dioxide. Where there are zones Of crushing, that is, where there are trunk-channels for percolating waters, the amount of carbon-dioxide which may thus be liberated may be considerable. Another source for the carbon-dioxide is a process of silication ’, which Van’ Hise has previously explained, in which the silica taken into solution in the belt of weathering, as the result of the decomposi- tion of silicates by the carbon dioxide in the surface waters, percolates downwards into the belt of cementation and decomposes the carbonates of limestones and other rocks with the liberation of carbon dioxide. “Therefore, deep-seated waters are ever receiving contributions of oarbon- dioxide, and thus are continually more capable of taking metals in solution, until the waters reach conditions where silication does not occur, In this process of silication alone is believed to be an adequate source of carbon-dioxide, so that metals may be carried as bicarbonates and the water also hold a further excess of carbon-dioxide,’ -. CHAPTER XIV. i GEOLOG Y—continued. The Manganiferous Rocks of the Dharwar Facies, including the Gondite Series. General—Deposition of the Dharwar manganiferous sediments—Their partial metamorphism—Their more complete m»etamorphism—The alteration of the manganif»rous silicates—Mineral veins and intrusives—Manganese-ores in crys- talline limestones—Classification of the Dharwar manganese-ores. General. It has already been mentioned that the formation of the oldest The Dharwar period gneisses must have been followed by a period of of sedimentation. mechanical sedimentation characterized by the deposition of sands, clays, and conglomerates. During the same period various chemical sediments must also have been deposited, particularly limestones, and possibly various ferruginous rocks, such as limonites. The period of tectonic quiescence during which these sediments accumulated must have been of considerable duration, and the sediment- ation must have been interrupted at intervals by the eruption of con- temporaneous lava-flows. Although the general period of sediment- ation must have the same over the whole of what is now the Peninsula of India, yet it does not follow that this period of sedimentation began and ended at the same time in the various parts of the area. The whole of the series of sediments thus formed was then ar subjected to intense tectonic disturbances, by the ne con of Mick (is ieee ae the oldest gneisses more or less deeply and subjected to various degrees of metamorphism and consequent mineralogical and structural changes ; the degree of metamorphism produced naturally depending on the depth to which the particular sediments were folded in, that is on the intensity of the pressure and temperature to which they were subjected. In some cases this metamorphism was so pronounced that it is now extremely difficult to separate these rocks from the older rocks with which they are associated, so that the sediments of this period have to be mapped with the other Archean rocks as the metamorphic and crystalline complex, as in the districts of Balaghdt, Bhanddéra, Chhindwara, and Nagpur, in the Central Provinces, and in Narukot in the Bombay Presidency. In Cuap. XIV.] DHARWAR SERIES ; GENERAL. 281 other cases, where the metamorphism has been less severe, it is easy to separate off from the Archean complex the rocks corresponding to the sediments of this period, as in the Panch Mahals, Belgaum, Dharwar, North Kanara, Sandur, Mysore, Jabalpur, Singhbhum, and a part of Balaghét. The rocks thus’ separated from the Archean complex were first known as Tran- sition rocks, being grouped under this name with the Bij4wars and other rocks situated stratigraphically above the great Eparchean interval. But they have since received local names in different parts of India. The area in which these rocks first received a local name is the Panch Mahdls, where W. T. Blanford in i869 1 recognized that the rocks then classed as Transition or sub-metamorphic were in this area not the same as the Bijawars of Central India and the Central Pro- Mel) Chacipener vinces. He consequently proposed the name series. Champdner for these rocks after the ruined Muslim city of that name, situated on the edge of the outcrop of these rocks. In 1886 R. B. Foote proposed the name Dhdrwdr ? _ ...,. tor the rocks of this facies situated in The Dharwar series. Dharwdr, Bellary. and Mysore, as it was not then suspected that they bore any similarity as regards age to Blanford’s Champaner group. In the south of India the manganese-bearing rocks of the following districts have been recognized as Dharwar in age :—Belgaum, Dharwar North Kanara, Goa, Bellary, Sandur, Chitaldrug, Shimoga, and Tumkur. In a work published in 18913, Dr. King expressed the opinion that the rocks of Chutia Nagpur, previously designated by the convenient term ‘Transition’ are the equivalent of the Dharwdrs of Southern India. In 1904, whilst engaged in the examination of the manganese-ore deposits of the Jabalpur district, I came to the conclusion, as the result of a comparison of my specimens with those of other areas, and with the full concurrence of Messrs. Holland and Vredenburg, that the rocks of this area previously mapped as Bijawars are really of Dharwar age. Dr. Holland paid a special visit to this area to convince himself that the aspect of these rocks in the field supports the conclusion as to their age. When, in 1905, I visited the Chémpdner area, I was The Transitions. 1 Mem. G. 8S. I., VI., p. 203. 2 Rec, G. 8S. I., XTX, p. 98. 3 ‘Gold, Copper and Lead in Chota Nagpore and the adjacent country’, by W. King and T. A. Pope. Thacker, Spink and Coimpany, Caleutta,(1891), p. 3. It b 282 MANGANESE DEPOSITS OF INDIA; GEOLOGY. [Part II: struck at once by the extraordinary lithological similarity of the Ch4m- paner rocks to those of Jabalpur and their consequent probable Dhar- war age. During 1904, I was able to examine yet another area of the rocks The Chilpi Ghat of the type once classed as Transition, namely, the Se 2 series situated in the Balaghat and Raipur districts of the Central Provinces, which W. King, in 1885 1, called the Chilpi Ghat series after the locality in which they were first examined. This series consists of quartzites, slates, conglomerates, and traps, in the parts where it was first examined. It was traced further west into the western portions of the Balaghat district by P. N. Bose, and it was here that I was able to examine it. The rocks have here become more metamorphosed, so that the slates have passed into micaceous phyllites and the conglomerates have been rendered schistose. The lithological similarity of these rocks to those of Southern India is so marked that Mr. Maclaren, who has had considerable experience of the Dharwars of the type areas, and to whom I showed my Chilpi specimens, fully agrees with my supposition that the Chilpi Ghat rocks are of the same age as the The metamorphic Dharwars.2 The importance of this correlation is aa eee manifest when it is stated that very good evidence Balaghat area. has been obtained that a considerable portion of the metamorphic and crystalline complex of the four districts of Balaghat, Bhandara, Chhindwara, and Nagpur, namely that with which the man- ganese-ore deposits are more particularly associated, really consists of portions of the Chilpis that have been so much more severely meta- morphosed than in the areas further to the east that it has not yet been found practicable to map them separately from the other members of the metamorphic and crystalline complex. It must be noticed that all the correlations of these ancient rocks in different parts of India are based on lithological resemblances. This correlation is, however, supported by the stratigraphical position of these rocks, namely, folded in with the oldest gneisses, and separated by the great Eparchean unconformity from all the younger rocks. ae There is yet another area of metamorphosed Bhe Ariyalb setict- Arohiaan sediments,—in Rajputana and Central 1 Rec’. G, S, I., XVIII, p. 187. 2 Since this was written I have been able to see for myself portions of the Dhdrwars of Southern India, and to further convince myself of the probable equivalence of the Chilpis and Dharwars. Cuap. XIV.] DHARWAR SERIES: GENERAL. 283 India—where an attempt has been made to separate from the oldest gneisses a system of limestones, schists, and quartzites. To this the name Ardvalli has been given, after the hills of that name to which the rocks of this formation give rise. It is probable that more than one series of rocks has been mapped under this name, but the major portion of the Aravallis is probably equivalent to the Dharwars of Southern India. The term Arvali or Ardvalli was first adopted in 1877, by C. A. Hacket!. I have not had the advantage of visiting the typical Ardvalli area, but have visited what must be an extension of this series in Jhabua State, My examination of the rocks found there in the vicinity of the manganese-ore deposit of Kajlidongri, and of specimens of this series from Radjputana, has shown me what a striking resemblance there is, both lithologically and, as far as I have seen, in mode of occur- rence in the field, between the rocks of the Aravalli system and those of the Chilpi Ghat series of the Balaghat district, and the more meta- iso) deni valende morphosed equivalents of the Chilpis in the Bala- of the various serics. ghat, Bhanddra, Chhindwara, and Nagpur districts of the Central Provinces. And, as has been already explained, the Chilpis are to be regarded as the equivalents in the Central Provinces of the Dharwars of Southern India. Hence we are driven to the conclu- sion that the series that have received the following names, arranged in order of priority, are roughly contemporaneous:—Champdner (1869), Aravalli (1877), Chilpi Ghat (1885), Dharwar (1886), and portions of the metamorphic and crystalline complex of the Nagpur-Baldghdt area, Central Provinces. With regard to the question as to which term is to be adopted in ‘Chémp4ner’ the preference to the others, it is obvious that according prior term. to the rules of priority the term Chdmpdner should be used. This, however, is the name that has been the least used of all, whilst that which has been extended to the largest number of areas, has passed into most general use, and is known best to geologists and ‘Dharwar’ the most miners, is the term Dhdrwdr, the familiarity of tne Seen SOE name being largely due to the fact that the auriferous veins of Mysore are situated in the rocks to which this name was originally given. Since, however, the strict contemporaneity of these in various parts of India has not and never can be proved, partly because they are situated in isolated areas and partly because it does not seem probable that the sedimentation in the different areas can have 1 Rec, G.8.1., X; p.84. He Die 284 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [ Part II: started and finished at exactly the same points of geological time, it will probably always be considered preferable to employ the local names The term ‘Dharwar’ With a general understanding as to their rough adopted. equivalence. When, however, it is desirable to treat the rocks of the different areas as a whole, it will be better to use the most familiar of the local names, namely Dhdrwdr, in preference to that which has priority on its side, but happens to be the least generally known of all, namely Chdmpdner}. Now it so happens that, excluding the manganese-intrusives forming the kodurite series of Vizagapatam and Ganjam, all the manganese-bearing rocks of any importance that have been located in the great succession of rocks classed as Archean are associated with rocks belonging either to the Dharwars or to one of the local groups shown above to be their equivalents. Hence the manganiferous rocks of this type will be grouped together, as The manganiferous rocks of the Dhdrwdr facies or type. A list is given on page 240 of the areas in which manganese- ores have been found in rocks of this facies. The Deposition of the Mane anieroy Sediments of the Dharwar Period. I now propose to give a general statement as to the mode of origin and occurrence of the manganese-ore deposits of the Dharwar facies, and then in Chapters XV to XVII to explain this in detail with special reference to the occurrences in the Central Provinces and Jhabua, the areas with which I am most familiar and in which the most valuable deposits have been so far located. On page 280 I have described the rocks of the Dharwar facies as having been deposited as a vast succession of sediments, both mechanical and chemical, with the contemporaneous extrusion, in some areas, of lava flows. The evidence of the manganese-ore deposits shows that there must have been many basin-shaped areas formed in various parts of this region of deposition. Some of these basins must have been of large size, of the nature of large lakes or of small seas, whilst others may have ~ 1 My friend and colleague, Mr. E. W. Vredenburg, in an interesting booklet entitled ‘ A Summary of the Geology of India ’ (Thacker, Spink and Company, Calcutta ; 1907), p. 17, considers that the term Ardvalli should be adopted ‘as it is derived from one of the s:sost remarkable and one of the oldest physical features of the globe. There is super-abundant evidence, however, that these rocks correspond with those known in other parts of the globe as the Huronian, and the use of a local designation for the Indian area is therefore superfluous.’ The treatment of the Archzan rocks in his book is very interesting, although I do not agree with it entirely. Cuar. XIV.] DHARWAR SERIES: DEPOSITION. 285 been quite small, These basin-like areas were areas of deposition, both mechanical and chemical. Sometimes the incoming waters were comparatively clear and free from mechanically-carried material, such as sand or clay, but, instead, contained in solution salts of manganese, On reaching the masses of more or less stationary water the velocity of the incoming waters was checked, and, in the more or less still condition to which they were brought, the solutions were either sub- jected to atmospheric oxidation with the consequent formation and precipitation of oxide of manganese, or they were subjected to the action of reducing agents with the precipitation of the manganese in form of carbonate, or, much more improbably, of sulphide, according to the nature of the reducing agent. It is considered that the former alternative is in all probability the correct one, although the latter mode of deposition, namely, as carbonate, and possibly in very rare instances as sulphide, may have been locally operative, where the conditions of deposition were reducing instead of oxidizing, as must usually have been the case. As long as the incoming waters were free from silts the deposits accumulating on the bottoms of the basins must have been entirely chemical and composed of more or less pure oxides of mangan- ese. But when the waters contained a moderate amount of silt, as well as the manganese salts, then the manganese oxides deposited must have been rendered siliceous by mechanical admixture with sand or clay. At other times, there must have been an alternate deposition of mangan- ese oxides, either pure or impure, with layers of sand or clay partly or entirely free from manganese oxides ; the layers of silt being deposited at times of flood, when the incoming waters had so diluted the man- ganese-bearing solutions with waters charged with silt that the sediments deposited consisted almost entirely of sand or clay. After the finish of the period during which manganiferous sediments were deposited, there came a time when the supply of manganese-bearing solutions ceased and the whole succession of manganese-bearing sediments was buried beneath a great thickness of sands, clays, and other sediments. The source of the Lhe manganiferous solutions themselves must have manganese. been supplied from an area in which the rocks then subject to meteoric influences contained compounds of manganese liable to be decomposed under the action of such influences. For such a source we can probably look to some plutonic rock containing manganese-bearing silicates amongst its constituent minerals. The ordinary ferro-magnesian silicates usually contain small quantities of manganese, and this would no doubt be sufficient under 286 MANGANESE DEPOSITS OF INDIA: GEOLOGY. f[ Part II: favourable circumstances to furnish the requisite quantities of manga- nese. It so happens, however, that there is in India a series of rocks, namely the kodurite series of Vizagapatam, that contains an unusually large amount of manganese as an essential constituent of its garnets and pyroxenes. There is no evidence available to show the relative ages of the kodurite and the Dharwar series, but we must not lose sight of the possibility that the manganese deposited in Dharwar times was derived, not from the small quantities of this element contained in the ferro-magnesian silicates of such ordinary rocks as granites or diorites, but from rocks specially rich in manganese ; and, if not actually trom the kodurite series, then from some other series of rocks, equally rich in manganese, that has either been entirely buried beneath later rocks, or is in existence somewhere at the surface and yet awaits discovery. The Partial Metamorphism of the Manganiferous Sediments. After this vast succession of sediments had accumulated, or perhaps towards the end of their deposition, they (and all the older rocks) were involved in a prolonged and severe tectonic disturbance, which folded them in with the older rocks, and produced in them varying degrees of structural and mineralogical change according to the depth to which they were folded in, and consequently according to the in- tensity of the pressure and heat to which they were subjected, When the intensity of this metamorphism was not very great the clays were simply converted into slates or phyllites (usually referred to as argillites in Southern India); the sands were converted into quartzites or sand- stone-quartzites of varying degrees of induration, often assuming jas- peroid or hornstone-like characters, perhaps due to partial chemical solution and re-deposition; whilst the conglomerates were rendered more or less schistose. Any ferruginous sediments were converted into hematite, and less frequently into magnetite, thus giving rise to the Formation of pri: banded hematite-jaspers, often contaming mag- mary ores. netite, that are so characteristic of the Dharwars. Any bands of manganese oxide that were contained in these sedi- ments were compressed and rendered crystalline. The ores so formed may be termed primary ores. The rocks of the Dharwar facies that have suffered this amount of metamorphism are the typical Dharwars of Dhar- war, Bellary, and Mysore, the Dharwars of Singhbhum and Jabalpur, the Chilpis of Balaghét, and the Champéners of the Panch Mahals. Of GEOLOGICAL SURVEY OF INDIA. Memoirs, Vol. XXXVII, Pl.g Photo. by H. B. W. Garrick. Calcutta Phototype Co, BANDED HEMATITE QUARTZITE ; FROM KHATOLA, JABALPUR DISTRICT, C, P, THE JASPERY QUARTZITE BANOS APPEAR WHITE IN THE PHOTO, BUT ARE REALLY PINKISH. Cuap. XIV.] DHARWAR SERIES : SECONDARY ORES. 287 the manganese-ores occurring in these areas, the following are considered to be primary ores :—(1) certainly those situated near Localities for the the base of the Chilpi Ghat series in the Balaghat primary ores. district of the Central Provinces, (2) probably a part of those of Sivardjpur in the Panch Mahals, and (3) possibly some of those of the Sandur Hills, although the available evidence r is against this. Since the Dharwar rocks have ormation of out- crop or recent secon- been exposed at the surface, other ores have en ores (lateritoid een formed by the concentration of the usually small quantities of manganese contained in some of the Dharwdr rocks, such as the ferruginous members of the series. Such ores can be termed secondary ores; or as there is another, and much more important group of secondary ores, formed in all pro- bability in depth in the Central Provinces and Jhabua, and considered on page 293, it will be better to refer to those formed on the surface as outcrop secondary ores, or alluding to their probable time of formation, recent secondary ores, whilst the ones formed in depth can be known as the deep or Archean secondary ores. The most important occurrences of outcrop secondary ores are in the Sandur Hills and Mysore, practically all the ores of both areas in all probability coming under this heading. The source of the manganese was probably partly original phyllites and partly ferrugi- nous quartzites. Amongst the outcrop secondary ores are those of Localities for out. Jabalpur, which have probably been entirely erop secondary ores. derived from the small quantities of manganese contained in the hematite of the hematitic jaspers by superficial alteration and concentration accompanied by the replacement of whatever rocks happened to be at the outcrop. Other outcrop secondary ores are those of Dharwar, a portion of those of the Panch Mahals, in both of which the manganese may have been concentrated from limonitic jaspers; and a portion, and possibly the whole, of those of Goa, North Kanara, and Singhbhum. In the last case the immediate source cannot at present be referred to ferruginous rocks containing a smal] quantity of manganese, because such rocks have not yet been found in the immediate neighbourhood of the manganese- ore deposits. The outcrops of nearly all these ores have a laterite- like or laterttoid aspect, and in Belgaum, Goa, and Jabalpur, manga- nese-ores are also found in what seems to be true laterite resting on rocks of Dharwar age. The distinction between the lateritoid ores and those in true laterite seems, however, artificial; because the field 288 MANGANESE DEPOSITS OF INDIA: GEoLOoGy. [ Parr II: evidence makes it clear to me that both have been formed by im- pregnation and metasomatic replacement of Dharwar rocks at the surface. [This statement does not apply to all varieties of laterite. | I do not propose to give here any detailed account of the geology and origin of the Dharwar manganese-ores of these less metamorphosed types. These subjects are, however, touched upon in the description of each district, the fullest accounts being given for Jabalpur and the Sandur Hills. The lateritic and lateritoid ores are dealt with later under the heading of laterite (see pages 380 to 389). The More Complete Metamorphism of the Dharwars, When the intensity of the metamorphism to which the Dharwar sediments were subjected was considerably more severe than described in the previous section, not only were the resultant structural changes more pronounced, but they were usually accompanied by a complete mineralogical re-arrangement or rather reconstruction of the rock. Sands were converted into vitreous quartzites in which any impurities crystallized out as definite minerals such as muscovite, hematite, garnet, or tourmaline, the formation of the last-named mineral possibly being due to the accession of various vapours to the mass of rock undergoing metamorphism. Very impure quartzites, grits, and conglomerates, often became completely recrys- tallized with the total obliteration of their original characters and the formation, in at least some cases, of gneisses, this change depending, of course, on the presence in the original sediment of a sufficient quantity of felspathic or other alkali-bearmg material to give rise to the fresh felspars of the gneiss formed by meta- morphism. Argillaceous sediments, such as clay, passed beyond the slate and phyllite stage and became entirely recrystallized as mica-schists, often crowded with various accessory minerals, such as rutile, tourmaline, Primary manganese 0d ottrelite. In the case of those deposits of ures formed by the manganese-ore that were originally laid down in nae se esed,, the comparatively pure condition, the only effect of ments. the metamorphism can have been to compress the ore into the smallest possible volume and consequently compel the various constituents of the ore to arrange themselves as the mineral aggregate that occupies the least volume, that is, to bring about the formation of the minerals of the highest specific gravity. Any Cuap. XIV. } DHARWAR SERIES: METAMORPHISM. 289 siliceous material that had become mixed with the manganese oxides combined with them to form the crystallme and com- paratively dense mineral, braunite, whilst the manganese oxides left over after all the available silica had been used up in the formation of braunite combined with the remaining impurities to form various man- ganates, which when mixed together isomorphously form the mineral psilomelane. This psilomelane forms the matrix in which the braunite granules are set, acting as a sort of cement to them. In the case, then, of comparatively pure manganiferous sediments, the chief difference between the ores produced by the less pronounced metamorphism noticed in the previous section and that noticed in this, lies in the fact that in the former case any silica mixed with the manganiferous sedi- ments frequently remained after metamorphism in mechanical ad- mixture with the manganese-ore, which was thus only able to assume the form of psilomelane; whilst in the latter case the intensity of heat developed was almost always sufficient to cause the formation of braun- ite, with the consequent production of a denser and more crystalline ore. There is, of course, every gradation between these two types, and both may be included under the term primary ores (see page 286). It is, however, in those bodies of manganese-ore in which there Formation «f the Were layers of sand, clay, or other sediment, defi- manganese silicates, nitely interstratified with the layers of man- spessartite and rho- : : : : donite, in the ore- ganese oxide , or in which the ore-body consisted bodies. of manganese oxides rendered impure by the admixture of considerable quantities of sand or clay ; and at the peri- pheries of the ore-bodies where the manganese oxides come in contact with the sediments forming the ‘country’ or wall-rock of the ore deposit, that the degree of metamorphism to which the rocks have been subjected is found to produce the greatest differences. As has already been explained, in the less metamorphosed type both the interstratified layers of silt and the ‘country’ of the deposits were simply converted into sandstone-quartzite, quartzite, slate, shale, etc., whilst the manganese oxides were compressed and rendered more or less crystalline. In the more metamorphosed type, however, the man- ganese oxides have interacted with any interstratified or admixed silt and with the ‘country’ or wall-rock. The product of this reaction has been various according to the nature of the silts and impurities. The chief products have been a manganese-garnet, and rhodonite, a manga- nese-pyroxene. The garnet approximates, as far as can be judged from two analyses, to the manganese-alumina-garnet, spessartite, the theoretical 290 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [| Parr II: composition of which is expresed by the formula :—3Mn0.Al,03. 38105. As will be seén, however, from the analyses given on page 351, the manganese is usually partly replaced by calcium and magnesium, and the alumina by iron. The formation of the spessartite of the theore- tical composition may be expressed by the following equation :— 2H20.Al203.2S8i02 + 3Mn0 +SiO2g = 3Mn0.Al203.3Si02 + 2H20. Kaolin or clay Quartz Spessartite By the introduction of oxides of calcium, magnesium, and iron, repre- senting calcareous, magnesian, and ferrugmous impurities, respective- ly, in the original sediments, into both sides of the equation, the form- ation of spessartite containing these constituents could be shown. This shows that when the sediments admixed, interstratified, or in contact with, the manganese oxides were largely argillaceous, the chief mineral formed was spessartite. Any excess of quartz in these sediments over the kaolin crystallized out as quartz with formation of spessartite-quartz- rock, if all the manganese had already been used up in combining with the kaolin. Whilst, if any manganese oxide were still left over, it com- bined with this excess of quartz with the formation of the triclinic man- ganese-pyroxene, rhodonite, of the theoretical composition expressed by the formula MnSi03. No analysis has yet been made of Indian rhodonite, so that it is not possible to say if the manganese of this mineral is replaced by any other element to any considerable extent. Assuming the theoretical formula, the following equation will express the form- ation of this mineral :— Mn02+Si0zg = MnSiOsz. Quartz Rhodonite If, after this equation had been carried out, there were any silica left unaccounted for, it would crystallize out as quartz, and the rock then formed would be spessartite-rhodonite-quartz-rock. If the quantity of manganese were such that there would be an excess of manganese oxide left over after supplying that required to combine with all the sand and clay in the formation of spessartite and rhodonite, then the last portions of the silica, instead of forming rhodonite by combining with one molecule of manganese oxide for every molecule of quartz, would probably combine with a much larger quantity of manganese oxide with the formation of braunite according to the following equation :-— 4Mn0+3Mn02+Si0g = 3Mn203.MnSi0g Braunite. Cuap. XIV_] DHARWAR SERIES: METAMORPHISM. 291 The rock then formed would be a spessartite-rhodonite-braunite-rock, or a spessartite-braunite-rock, according as there had or had not been sufficient quartz to form rhodonite. In the event of the silts not con- taining any appreciable quantity of clay or other aluminous matter, no spessartite would be formed and the product would be rhodonite- rock, rhodonite-quartz-rock, or rhodonite-braunite-rock, according to the relative proportions of the manganese oxides and the silica. It will be noticed that in all the equations given above, except that for the formation of braunite, the manganese has been assumed to be in the Liberation of protoxide form ; but as has been already explained water, oxygen, and - 22 = #3 ale” at carbon the manganese was in all probability originally dioxide. deposited as the result of the oxidation of man- ganese-bearing solutions, and therefore presumably as the hydrated peroxide, H,MnO,. This simply means that during the changes described above oxygen must have been set free in the formation of spessartite and rhodonite, whilst in the formation of the manganese- garnet water must have also been liberated. If any appreciable quantity of the manganese was deposited as carbonate, then in the majority of cases this must have been broken up by interaction with other substances to form either oxide-ores of manganese or silicates of manganese, such as spessartite and rhodonite. In any case this breaking up can only have been accomplished with the evolution of carbon dioxide, as in the following equation showing the change by which thodonite may have been formed from manganese carbonate :— MnC03 + Si02=MnSi03 + COs In a few cases manganese carbonate, in the form of the mimeral rhodo- chrosite, has been found ; but these are very few, the only cases known to me being the deposits of Gaimukh and Devi in the Chhindwara district, Central Provinces, and doubtfully the deposit of Parsioni in the Nagpur district, Central Provinces. But whether this rhodochrosite is to be considered as a remnant of that originally deposited at the time of deposi- tion of the Dharwar sediments, or whether it has been subsequently formed under the imfluence of waters charged with carbon dioxide percolating through the deposits, it is not possible to say. As the result of the series of changes described above those bodies of manganese-ore that were originally deposited as solid masses of manganese oxides, without any large quantity of admixed silt, and free from interlamimations of sand or clay, are still found as solid masses 292 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Parr IT: of manganese-ore ; except at their peripheries, where they are separated Formation of man- from the practically non-manganiferous ‘ country ’ pens uae 2 be by an envelope of gneiss, schist, or quartzite, con- peripheries 0 nae Be AE es dep- sits. taining silicates more or less rich in manganese. These silicates have in some cases, no doubt, been formed by the interaction of the manganese of the ore-body with the surrounding ‘country’; but in many cases the formation of these manganese-silicates must have been due to the fact that the sediments immediately over- and underlying the ore-body were mixed with manganese oxide at the time of their deposition, owing to a more or less gradual change from the deposition of manganese oxide to that of sand orclay, or vice versd. As examples of such border products due to one of the causes outlined above mention may be made of the spessartite-bearing gneisses and quartzites occurring on either side of the ore-bodies at Kandri and Mansar in the Nagpur district ; whilst the formation of the schist con- taining the manganiferous variety of amphibole to which the name of winchite has been given, at the Kajlidongri mine in Jhabua State, and of the schist containing manganiferous micas as one wall of the Sita- pathur deposit, are instances of this same phenomenon of the formation of manganese silicates at the periphery of a deposit, although neither deposits can be cited as an example of a solid mass of manganese-ore free from appreciable quantities of foreign material. On the other hand, those ore-bodies that contained intercalated layers The banded struc. Of sand or clay have suffered great alteration. In ture of the ore-bodies. ¢ases where the alternating layers of ore and silt were thin, averaging, say, 1 to 3 inches each in thickness, the temperature and pressure to which they were subjected has often been sufficiently high to cause such a complete interaction between the ore-layers and Silt that all the ore has been converted into spessartite or spessartite-quartz- rock ; the resultant rock has a banded appearance owing to the alter- nation of bands of spessartiferous rock with bands of vitreous quartzite, roughly corresponding to the layers of manganese oxide and silt, respec- tively. When these layers were originally somewhat thicker the reaction may not have extended right to the centre of the ore-layer. so the central zone of a layer may consist of manganese-ore with, on each side of it, a layer of spessartiferous rock separating the ore-layer from other bands corresponding to the original layers of silt. In some cases the alternating layers of ore and silt may have been so fine that the whole mass of rock has passed into a more or less homogeneous mass of spessartite-quartz-rock, or of spessartite-rock practically free Cuap. XIV.] DHARWAR SERIES ; ALTERATION. 293 from quartz, the presence or absence of this constituent depending, of course, on the exact composition of the silt. Rhodonite is formed much less commonly, although it is to be found in almost every deposit where the degree of metamorphism has reached the point sufficient to bring about the formation of spessartite, the local presence of rhodonite at any particular point being simply determined by the actual com- position of the silt and adjacent or admixed ore at that point. Other rarer silicates have also been formed in places, probably where the sedi- ments or manganese oxides happen to have had an exceptional com- position. The manganiferous sediments must also have contained a varying quantity of phosphorus, in what form it is impossible to say, but probably as apatite. Whatever was its original form, it is now found as apatite in the meta- morphosed rocks, sometimes only in very small quantities, and some- times, though rarely, in comparative abundance, as at Jothvad in Narukot State, Bombay Presidency. Apatite. The Alteration of the Manganiferous Silicates. The evidence collected at the various deposits in the Central Provinces f shows that a considerable portion of this spessartite Re-ccnversion cf ; . spessartite and rho- and rhodonite has been reconverted into mai- donite into oxidized ganese-ore. Many examples are to be found of ores (deep secondary ae ores). rocks made up of these manganese-silicates traversed by veins and patches of manganese- ore. In some cases this alteration has become so complete that the fact that the ore was originally a rock made up of manganese silicates would not be suspected, were it not for the occasional find in the midst of asolid mass of ore of a residual patch of yellow spessartite or pink rhodonite. It might be suggested that this supposed residual manganese silicate is really a feature of the deposit due to the presence in the mass of oxides of patches of impurities, which, under the influence of metamorphic agencies, were converted into silicates. The evidence that such is not the case will be given later. Reasons will be given later (page 355) for supposing that this alteration of silicates to ore took place in Archean times whilst the rocks were still at some distance from the surface. These ores can therefore be termed deep or Archean secondary ores in contradistinction to the surface or recent second- ary ores mentioned on page 287. Accepting for the present that it is certain that portions of the manganese-ore bodies have been produced by the 294 MANGANESE DEPOSITS OF INDIA; GEOLOGY. [Part II: chemical alteration of manganese silicates, such as spessartite and rhodonite, the question at once arises as to what proportion of the ore- bodies as we now see them consists of the original manganese oxides simply compressed and to a certain extent recrystallized and what proportion of them consists of ores formed by the chemical alteration of manganese silicates. I have not yet found sufficient evidence to settle this question, but it seems possible to specify certain instances of either. Thus the solidity of the portion of the Kandri deposit in South Hill is such that it seems difficult to imagine that it has been formed solely by the chemical alteration and replacement of masses of spessart- iferous or rhodoniferous rock ; so that it seems more rational to suppose that this is an example of a mass of manganese oxide deposited as such and since compacted and recrystallized ; but, considering that the saddle separating North from South Hill contains a large quantity of spessar- tite, it is possible that this deposit may after all have been formed by the alteration of manganese-silicate-rocks. The Balaghat deposit may, however, be cited as an undoubted example of a deposit that has not passed through the silicate stage, because it contains in it numer- ous bands of quartzite that have not been sufficiently metamorphosed to have even given rise to spessartite or rhodonite. As a good example of a deposit the ore of which has probably been derived, perhaps almost entirely, by the alteration of spessartiferous rock, the Mandri deposit may be cited, whilst the Manegaon deposit, also in the Nagpur district, is a good example of a deposit in which the ore has been derived from both spessartite and rhodonite. The question next arises as to when this alteration of the manganese silicates took place. It has already been shown that during the Tine of alten metamorphism of the manganese-ore deposits, water, of the manganese oxygen, and probably, in some cases, carbon dioxide, anes must have been liberated. These substances would then have probably been available to act on the deposits as soon as the pressure was somewhat released, remaining in the meanwhile in the form of waters containing, as a portion of their burden, oxygen, and a certain proportion of carbon dioxide. Hence it seems probable that, as soon as the pressure became locally lessened, the percolating waters would begin to attack the manganese silicates. This attack must probably have continued for a considerable time after the cessation of the movements that folded and metamor- phosed the Dharwars, probably in fact as long as the temperature was at any considerable elevation above that of water at the surface of the CHap, XIV.] DHARWAR SERIES: ALTERATION. 295 earth. There is no evidence that this alteration is going on at the present day, except perhaps to a very insignificant extent. Coming now to the way in which this alteration was effected, the evid- Method of alter. Cnce obtained by the microscopic examination ation ofthe manganese of a large number of thin sections of spessartite- silicates. and rhodonite-bearing rocks in all stages of alter- ation to manganese-ore indicates that, in the case of spessartite, the mineral did not as a rule decompose in situ with the solution and removal of the alumina, silica, lime, and magnesia, and the resultant residual concentration of the oxides of manganese and iron. On the contrary, the garnet was attacked in one place with the solution of the manganese, which was carried in solution to another part of the deposit, where it replaced not only the spessartite already there, the manganese and iron contents of this replaced garnet being no doubt added to the oxides of manganese and iron brought in by the replacing solutions ; but also the quartz, when the spessartite occurred as spessartite-quartz-rock. If the formation of the manganese-ore had been brought about by the decomposition in situ of the garnet and the accumulation of the manganese oxides, then the resultant ores would have been porous, unless further supplies of man- ganese had been subsequently brought in to fill up the interspaces. On the other hand, if the formation of the ore took place by replacement, as is suggested by the microscopic aspect of these rocks, the resultant ores should be compact, as is the case. Hence the evidence of the physical aspect of those ores that can fairly be supposed to have been derived from the spessartite-bearing rocks supports the theory that such ores were largely formed by replacement. But it must be noticed that this feature of the ores, namely, whether porous or compact, is not necessarily good evidence of the way in which they were formed, because their formation probably took place at such a depth that the pressure there existing may have been sufficient to close up any small open spaces and render the ores more compact than they would otherwise have been, though probably not as compact as an ore formed by replacement. In the case of rhodonite the ores seem to have much more frequently formed by the alteration of the mineral in situ, the alteration of the mineral starting along cracks and gradually spreading throughout the whole crystal. In cases where the rock contained both spessartite and rhodonite the latter mineral is frequently found nearly or completely altered to manganese oxides whilst the garnet remains perfectly fresh 296 MANGANESE DEPOSITS OF INDIA : GEOLOGY. [Pan IL’ Mineral Veins and Intrusives. The waters that percolated through the masses of manganese-silicate- rock and manganese-ore towards the end of the fold- Percolation ole yi rae, : mineralized waters ing of the Dharwars must, however, have contained during the metamor- many other substances in solution besides oxygen phism of the ore- Gre E z bodies. and carbon dioxide. In fact, if one can judge from the unusual minerals often found in the manganese- ore deposits at the present day, these waters must have contained arsenic, barium, and possibly some of the rare elements, as evidenced by the presence of arsenates at Kajlidongri in Jhabua and Sitapdér in Chhindwara, by the almost invariable presence of small quantities of arsenic in the manganese-ores of the Central Provinces, and by the presence of barytes at Chargaon in the Nagpur district. More- over, probably during the folding, the Dharwars were at times frac- Veins traversing tured with the formation of fissures that acted the ore-bodies. as a passage for mineralized solutions. The best example of this phenomenon is at the Kajlidongri mine, where the ore- beds are traversed by a series of quartz veins containing barytes, a com- plex arsenate, and the manganate of barium, iron, and manganese, to which the name of hollandite has been given. The manganese-ores also frequently contain very small quantities of nickel and cobalt, and more rarely of copper, zinc, and lead. It is, of course, not possible to say whether these rarer constituents were present in the manganiferous sediments as originally deposited or whether they were subsequently introduced. It seems probable, however, that they were to a large extent introduced into the deposits during the time that they were being folded and subjected to high pressures and temperatures, this especially applying to the veins. The source of these introduced constituents was probably heated waters derived from masses of plutonic rock, whence they brought their metalliferous burden. In many of the deposits, as exposed in the mines, masses of peg- Rocks intrusive in Matite or other acid igneous rock are found, con- the ore-bodies. cerning the intrusive relation of which with regard to the manganese-ore bodies there is often unequivocal evidence. These intrusives would no doubt have solidified in the majority of cases as ordinary granite or pegmatite veins, had they traversed ordinary gneisses, schists, or quartzites. But in piercing the manganese-ore bodies they took the opportunity to absorb portions of the rocks through which they passed, with the consequence that when they solidified the absorbed Cuap. XIV,] DHARWARS : CRYSTALLINE LIMESTONES. 297 manganiferous material gave rise to minerals not usually found in such intrusives. Amongst such occurrences the following may be specified :— 1. The manganese-pyroxene, blanfordite, in a rock made up of quartz, microcline, and albite or oligoclase-andesine ; at Ramdongri, Nagpur district. 2. Crystals of blanfordite, associated with juddite and _braunite, in a rock composed chiefly of albite, but sometimes con- taining quartz as well; at the Kacharwdhi mine, Nagpur district. 3. A slightly manganiferous pyroxene, with pinkish brown to green- ish brown pleochroism ; at Kachi Dhana, Chhindwara district. 4. Crystals of yellow manganese-garnet in microcline-rock; at Beldongri, Nagpur district. 5. Yellow manganese-garnet in a pegmatite made up of quartz and felspar, the latter being usually either microcline or albite-oligoclase ; at Sitapathtir, Balaghat district, and Bichua and Ghoti, Chhindwara district. 6. Red manganese-garnet in thin veins of granite made up of quartz and felspar (microcline, orthoclase, and oligoclase) traversing the manganiferous rocks; at Jothvad, Narukot State. 7. A manganese-pyroxene showing the blanfordite type of pleo- chroism, in thin veins composed of intergrown micro- cline and oligoclase, with subordinate quartz. This rock also contains greenovite, the manganiferous variety of sphene ; also at Jothvad. 8. Felspar (microcline)-braunite-rock with felspar crystal faces developed in cavities ; at Sdtak, Nagpur district. Manganese-ores in Crystalline Limestones. There is yet another mode of occurrence of manganese-ores in rocks that are probably to be regarded as an integral portion of the sediments deposited in Dharwar times, namely that characterized by the occur- rence of the ore in crystalline limestone in association with the manga- niferous epidote, piedmontite. But I have separated these from the remainder of the manganese-ore deposits of Dharwar facies, because they constitute a distinct mode of occurrence. On pages 195 to 206 of a paper published in Volume XXXIII of the Records of the Geological Survey of India, I have given descriptions of various specimens of crystalline limestone collected in the Chhindwara IE 298 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [PART I district of the Central Provinces, whilst on pages 168 to 172 of the same paper I have discussed the origin of these rocks. The crystalline lime- stones are there divided into three groups as follows :— 1. Limestones containing some or all of the following accessory minerals :—diopside, hornblende, tremolite, quartz, epidote, essonite, sphene, magnetite, and mica. 2. Manganiferous limestones, often containing spessartite and rhodonite, and black in colour due to the deposition of man- ganese oxide along the cleavage and twinning planes of the calcite. 3. Serpentinous limestones and cipollinos, usually dolomitic, and resulting from the chemical alteration of original white pyroxene-rock, sometimes containing phlogopite, and, more rarely, spinel and chondrodite. It 1s not necessary to consider here whether the rocks from which the limestones of Class 3 are supposed to have been derived are of Dhar- war age, or a portion of the more ancient platform on which the Dharwar sediments were deposited; for they have no connection with the man- ganese-bearing rocks. The Archean rocks of this district have been so metamorphosed that they have all been mapped together as the metamorphic and crystalline complex, and no attempt has been made Dhirwirs in the to distinguish the portions of this complex that Chhindwara district. are to be regarded as the equivalents of the Chilpi Ghat series of the Balaghdt district, that is the portions that are of Dharwar age. Consequently in the above-mentioned paper neither of the terms Chilpi and Dhérwar was used. It seems probable, however, that, of the rocks given in the classification on page 167 of that paper, Groups IV and V, and a portion of Group III, are to be regarded as belonging to the Dharwar system; whilst, as will be explained below, the probability is that Groups VI and VII and the first two sections of Group VIII also belong to this same series of rocks. The evidence put forward in that paper is held to justify the con- The origin of the clusion that limestones of Class 1 (above) have been a eee and crystal. formed by the chemical alteration of rocks similar to, line limestones. or identical with, a group of rocks there called the guartz-pyroxene-gneisses. No analysis has ever been made of these gneisses, but a glance at the list of minerals they contain is sufficient to show that they may easily have been produced by the metamor- phism of impure calcareous sediments. The alternative to this is to Cuap. XIV.] DHARWARS : CRYSTALLINE LIMESTONES. 299 suppose that these gneisses have solidified from igneous fusion. Such a theory would, however, need the hypothecation of a magma of very m- usual composition, so that it is preferable to suppose that they are meta- morphosed sedimentaries. They may have been formed either during the Dharwar period of sedimentation, or previously ; but not later, for they have been involved in the Dharwar folding. From their genetic relationship to the crystalline limestones, and the fact that one variety of these limestones is manganiferous and hence probably of Dharwar age— although it is not impossible that some of the pre-Dharwar sediments were manganiferous—it is probable that the sediments from which these gneisses may have been derived were deposited in Dharwar times. Since the formation of the crystalline limestones is supposed to have been effected through the agency of alkaline solutions containing carbon dioxide, we must suppose that their formation took place during or towards the end of the folding of the Dharwars, when the rocks were at such a depth that they were at a high temperature and pressure, so that the conditions permitted of great molecular mobility. We can suppose that under the influence of the great heat and pressure the calcareous sedi- ments were converted from impure limestones into calcareous gneisses with the expulsion of large quantities of carbon dioxide. The gas so expelled was probably kept in solution at a high temperature and pressure in the waters that must be present in all rocks at a great depth ; and as soon as the intensity of the pressure and heat conditions somewhat abated these waters, charged, as they must have been, with alkalies in addition to the carbon dioxide expelled from the calcareous sediments on their conversion into gneiss, at once began to attack the recently-formed gneisses and reconvert them into limestones. Sufficient carbon dioxide would have been available to completely change the gneisses back into limestones had it all remained in the proximity of the gneisses until the conditions became suitable for this reconversion ; but the mere fact that the reconversion was not completed shows either that a considerable portion of it was removed from the scene of action, no doubt in the ordinary course of circulation of the waters, before the time came for this reversal of the process by which it was set free or that if it all remained present the favourable conditions did not last long enough for the reconversion to be completed. This explanation will account for the fact that it is possible to find these gneisses in every stage of alteration into crystalline limestone, better than any other I can think of, and seems to be in complete accordance with the facts of occurrence and association of these rocks in the field. It has been introduced here IE 2 300 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part II: because various colleagues, on account of the plausible and probably correct theory that these very gneisses were formed by the metamorphism of impure calcareous sediments, have cast doubt on the reality of the passage of rocks similar to or identical with the quartz-pyroxene- gneisses into crystalline limestones. The theory outlined above shows that it is possible for impure calcareous sediments to have been first converted into very calcareous gneisses and then to have been partly reconverted into crystalline limestones. Moreover, this reconciliation of the two theories also allows for the case of pure or comparatively pure sediments being converted directly into crystalline limestones without passing through the gneiss stage. It must be noticed, how- ever, that since the quartz-pyroxene-gneisses contain felspars, such as microcline and labradorite, both contaiming considerable amounts of alkalies, it follows that if these gneisses really were derived from calcareous sediments, the sediments must have contained considerable quantities of potash and soda. In the paper cited above the origin of the manganiferous limestones The jee of the 28 not discussed, simply because at that time no manganiferous lime- evidence had been found to show whether their BLOne® origin was the same or not as that of the non-manga- niferous limestones with which they are often intimately associated. Subsequent microscopic work has, however, shown that their origin is the same. These manganiferous limestones have only been found in the Nagpur and Chhindwara districts in the Central Provinces. In the Chhindwara district they contain spessartite and rhodonite, but no piedmontite, and are, moreover, of a dark brown to black colour owing to the secondary deposition of manganese oxides along the cleavage and twinning planes of the calcitel. At every occurrence in the Nagpur district, however, these limestones contain piedmontite, both in scattered grains and in nodules, the limestone matrix in which they are set being usually of a light colourand not blackened by the secondary deposition of man- ganese oxide, although the blackened limestones are also of frequent occurrence. The limestones as a rule also contain small bands and nodules of a brilliantly crystalline manganese-ore. Moreover, some of the nodules are of complex composition, consisting partly of piedmontite and partly of manganese-ore. The microscopic examination of these limestones usually shows crystals of piedmontite (Plate 10, fig. 4,) ma 1 Loc. cit., pp. 200, 201; and Plate 17, fig. 1 EXPLANATION OF PLATE 10. PHOTOMICROGRAPHS, Fic. 1.—Quartzite—light ; manganese-ore-—black. Fie, 2,—The section shows piedmontite (dark) in a light-coloured matrix of plagioclase and orthoclase, with a certain proportion of apatite and quartz. Tans Fic, 3,—The black represents piedmontite, the grey is orthoclase, and the white is secondary calcite. Tc, 4,—The dark mineral is piedmontite and the light is calcite. GEOLOGICAL SURVEY OF INDIA. Fig. 1.—X 23. Fine-grained quartzite being replaced by manganese-ore. Sivarajpur, Panch Mahals district, Bombay Fig. 2.—X 23. Piedmontite-gneiss. Pali, Nagpur district, C.P. L. L. Fermor, Photomicrograph. Fig. 3.— X 23. Piedmontite and felspar, latter altering to calcite. Ghogara, Nagpur district, C. P. Bemvrose, Collo., Derby. Fig. 4.—X 22. Piedmontite in crystalline limes iedmontite in crystalline limestone. Ghogara. ie ‘ at we? wy Cuap, XIV.| DHARWARS: PIEDMONTITE GNEISSES, 301 matrix of calcite showing no signs of derivation from any other mineral ; but, in one case, namely, Ghogara in the Pench river near Parsioni, I was fortunate enough to find an example of a piedmontite-bearing gneiss Bicdiovitte: eucia- showing the same process of chemical alteration ses. of felspar into calcite as I had so often found in connection with the non-manganiferous limestones. (Plate 10, fig. 3). I had collected this specimen as an example of a piedmontite-bearing limestone, so that it is possible that a far larger proportion of these supposed limestones are really gneisses, partially converted into lime- stones, than would be suspected from their appearance in the field. Piedmontite-gneisses were also found at Pali (Plate 10, fig. 2). Assuming that these gneisses are only metamorphosed sediments, Rca ae Forint the formation of the manganiferous limestones tion cf the manganji can be explaimed in the followmg way. During eo Emestoues: the deposition of the Dharwar sediments there must have been periods when the sediments deposited were of a predominantly calcareous character. This deposition took place no doubt in water of some depth, such as the bottom of a sea or large lake. At times the depo- sition was only chemical leading to the production of pure limestones, but this must have been a rare case. Much more frequently a certain pro- portion of mechanical sediment was laid down at the same time, the proportion being sometimes very considerable, even as much as half the total deposit. In a certain number of cases, really forming but a small proportion of the whole, nodules, thin lenticular seams, and in a few rare cases small beds of manganese oxides, were deposited, probably in the same way as nodules of manganese-ore are being formed on the bottoms of the present-day oceans ; namely, by some process of segre- gation, due to the power of a particle of manganese oxide, once deposited, to bring about the deposition round itself as a nucleus of small quantities of manganese salts dissolved in the neighbouring waters. The nodules and patches of manganese oxide, thus laid down, and subsequently covered up by a further deposit of calcareous matter, were no doubt often rendered impure by admixture with siliceous materials. In other cases, manganese must have been deposited with some uniformity throughout a considerable thickness of calcareous sediment, and in this case the deposition may well have been as carbonate. Then came the period during which the Dharwar sediments were folded and metamorphosed. Those sediments that were sufficiently impure were converted into gneisses, of course with liberation of carbon dioxide and water; and in these gneisses the impurities 802 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part II: crystallized out as diopside, epidote, garnet, microcline, plagioclase, and sphene, etc. If the sediment contained a fair quantity of manganese, either as oxide or perhaps as carbonate, then the other impurities, instead of forming diopside, epidote, and ordinary Formation of pied- garnet, gave rise to the corresponding manganiferous raontite, spessartite 2 : é é : and rhodonite. minerals rhodonite, piedmontite, and spessartite, of which piedmontite was by far the most frequently formed. The rhodonite and spessartite have not been analysed ; but one would expect them to be more calcareous than the varieties found in the manganese-ore bodies previously considered, namely those that were formed by the metamorphism of the manganese-oxide sediments asso- ciated with non-calcareous sands and clays. There is no need to give equations for their formation as they would be very similar to those given on pages for the formation of non-calcareous spessartite and rhodonite. The formation of the piedmontite may be expressed by the following equation :— 2Mn203 + 2Fe203 + 5[2H20.Al203.2Si02] + 12CaCOg + 8Si02= Clay (kaolin) Calcite Quartz = 6[Cag(Al.OH)(Al,Mn, Fe)2(Si04)3] + 12CO2 + 7H20 Piedmontite in which the Al, Mn, and Fe, are for the sake of simplicity assumed to be present in the group (Al, Mn, Fe) in equal molecular proportions. In cases where the segregations were mixed throughout with various im- purities, the whole segregation was sometimes converted into pied- montite, often with the admixture of a little calcite or quartz or other impurity, the residue of the sediment mixed up with the manganese oxides. On the other hand, when the nodules, bands, or beds, of manga- Woduise tate nese oxide were deposited free or comparatively free ganese-ore and pied- from admixture with calcareous or other material, mioHbne: they were compacted on metamorphism into nodu- les, bands, or beds, of crystalline manganese-ore. As might be expected, many of the nodules, which is the commonest form that the segregations take, are of complex composition and composed partly of manganese-ore and partly of piedmontite. This may be due to the original segregations having been composed of manganese oxides in some parts free from, and in other parts containing, admixed impurities. On metamorphism the impure portions were converted into piedmontite and the pure por- tions into manganese-ore. In the specimen illustrated on Plate 14 one nodule is composed of manganese-ore inside with a peripheral zone varying from ,, to +, inch thick of piedmontite. This peripheral zone Cuap. XIV.] DHARWARS: CRYSTALLINE LIMESTONES. 303 was probably produced at the time of metamorphism of these rocks, by an interaction between the surface shell of the original manganese- oxide segregation and the surrounding calcareous sediment. I have not yet found evidence that any appreciable quantity of the manganese- Alteration of man. O%€ found in the crystalline hmestones has been ganiferous limestones, produced by the subsequent chemical alteration of the piedmontite, so that it can for the present be assumed that by far the larger proportion of the ores occurring in limestones are the product of the direct compression of the originally deposited oxides of manganese. In cases where spessartite and rhodonite were formed, however, subse- quent alteration has often taken place with the production of inferior ores. But as these two silicates have been much less frequently formed than piedmontite the ores so produced are not in sufficient quantity to be of much commercial value. Devi in the Chhindwara district may be instanced as a case of the formation of ores in this way. Subsequent changes have, however, often affected the piedmontite-bearing rocks. At every place where piedmontite limestones are found there is also found the black limestone, to the colouring of which by the deposition of manganese oxide along cleavage and twinning planes reference has already been made on page 300. In all these cases there seems to be a certain amount of spessartite and more rarely of rhodonite present, but it is not known whether all the manganese secondarily deposited in these black limestones has been derived from the spessartite or rhodonite, or whether the piedmontite has also contributed its quota. In one case, namely at Pali, in the Nagpur district, the limestone seems to have been bodily dissolved away with the formation of cavities in which Secondary forma- beautiful crystals of pyrolusite have been deposited, tion of pyrolusite. the manganese required for this process having no doubt been derived from the manganese silicates contained in the adjacent limestones. In other parts of the same mass of rock at Pali the whole rock has been replaced by chert, in which are often found shining particles of man- ganese-ore formed previous to the silicification of the limestone by the conversion into manganese-ore of whatever manganese silicate happened to be in the limestone, more probably rhodonite or spessartite than piedmontite. Manganiferous cherts. The nodules of manganese-ore are not usually composed of one The mineral compo- : : Pitontor Uae mitieence: mineral only. Analysis shows that they are as a ores. rule mixtures of braunite with a predominating amount of one of the manganates, hollandite or psilomelane. From 504. MANGANESE DEPOSITS OF INDIA; GEOLOGY. [Parr IT the frequently brilliantly crystalline character of the ores it is evident that the crystalline manganate, hollandite, is of common occurrence, the amorphous manganate, psilomelane, being relatively much less com- mon than in the ordinary manganese-ore deposits of the Nagpur dis- trict. At the exposure of crystalline limestones seen in the Pench river Folding and faulting at Ghogara the nodular bands, often 1 to 3 feet long of manganese-ore bands. and only 1 to 3 inches thick, are often seen to be folded and faulted ; in one case, in the small fault planes so formed, small flakes of a beautiful pink manganese-mica have developed. (See fig. 75 on page 963.) Classification of the Manganese-ores Associated}with the Dharwar Series. From the foregoing it will be seen that the manganese-ores of the Dharwar facies can be divided into two main groups; those associated with the less metamorphosed type of Dharwars, and _ these associated with the more metamorphosed type to which the name of the gondite series is given on page 306. Each of these can be dividea into secondary and primary ores. There are also the lateritic ores. I propose to now put forward a classification of all the manganese-ores of the Dharwar facies, and to include in this classification the lateritic ores formed on the outcrops of Dharwar rocks. It will be seen that this classification includes practically all the Indian manganese-ores, except those of the kodurite series and the lateritic ores formed on the outcrops of rocks, such as the Deccan Trap, that are not of Dharwar age. In this classification I note in the right hand column the ores characteriz- ing each method of formation. The names of the minerals are placed in order of importance in each case. In the case of the ores belonging to the divisions B.a and B.c, it is difficult to determine what proportion of the ores of the deposits of the areas given in B.c belong to each, and the distribution of the two minerals amongst the two groups may not be quite accurate. It will be noticed that the names of some of the areas come in two or even three places. As I have asterisked the occurrences that are at present (1907) being worked some idea can be formed as to which of the modes of occurrence in a particular area are of importance and which are not. I have not asterisked those ores that are quarried incidentally to the winning of other ores, but which by themselves are of no importance, Cuar. XIV. ] TABLE 22. DHARWAR ORES: CLASSIFICATION. 305 Classification, according to origin, of the manganese-ores associated with the Dharwar rocks. A. With the less metamorphosed type of Dharwars :— (a)—Primary ores :— Balaghat* Panch Mahals* Singhbhum*(?) (b).—Outcrop secondary ores (lateri/oid ores) :— Dharwar Jabal pur* Mysore* North Kanara Panch Mahals. Sandur Hills* Singhbhum* B. With the more metamorphosed type of Dharwars :— (a).—Primary ores :— a. Associated with the gondite series. Probably some in nearly all the areas mentioned in c. q.* 8. Associated with crystalline limestones. Nagpur district*. (b).—Outcrop secondary ores :— a, Associated with the gondite series. Probably some in nearly all the areas mentioned inc. a. 3. In cavities in crystalline limestone. Nagpur district. (c).—Deep secondary ores :— a. Associated with spessartite-and rocks (the gondite series). Narukot Jhabua* Balaghat* Bhandara* Chhindwara* 4 Nagpur* 8. Associated with crystalline limestones containing piedmontite, often spessartite, and rarely rhodo- nite rhodonite-bearing ‘Chhindwéra* Nagpur. C. In laterite resting on the Dharwars :— Belgaum* Goa* Jabalpur. \ Psilomelane and pyro- & Jusite ; rarely braun- ite and hollandite. \J ) | | Psilomelane, pyrolusite + wad, pseudo-mangan- | ite, and polinaite(?) J Same asc. a. ) Hollandite, braunite, psilomelane. |) Soft, dirty ores ; psilo- + melane and pyrolu- J site. Pyrolusite. > | Psilomelane, braunite, ‘ rarely hollandite, { sitaparite, vreden- burgite. s J ? Psilomelane, braunite, 5 and hollandite. ‘) Psilomelane, _pyrolu- > site, pseudo-man- J ganite, and wad. CHAPTER XV, GEOLOGY —continued. The Gondite Series. Origin and use of name—Areas where found—Nagpur- Balaghat area—Origin— ~ Occurrence in Jhabua—In Narukot. In the foregoing pages a general account has been given of the man- ganese-bearing-rocks of the Dharwar facies, in which the occurrences have been classified according to the degree of metamorphism they have suffered. Where the rocks have suffered the maximum amount of metamorphism they have often been completely reconstructed mineralogically, with the resultant production of many curious and interesting varieties. These can be distinguished with the utmost ease in the field from all the other rocks of the metamorphic and crystalline complex, and consequently, it has been thought desirable to bestow on these rocks a distinctive name for convenience both of reference and geological mapping. For this purpose the term gondite is proposed, the word being derived from the name of the race of so-called aboriginal inhabitants that is found over a large portion of the Central Provinces, especially those areas where the man- ganese-ore deposits are situated. The Gonds have already been once honoured in geological literature ; for the Gondwana system, the coal- bearing series of India, received its name from the country they inhabit, Further, this name has since been extended, in the form Gondwdna- land, to denote a considerable portion of the earth’s surface where rocks of similar age and characteristics are found. Owing, however, to the different form of the two words gondite and Gondwéna, it is not considered likely that any confusion will arise in their use, even though the minerals that happen to characterize the Gondite Series and the Gondwana System, namely, manganese-ore and coal, respect- ively, are both black in colour. This term, like the term ‘ charnockite ’ introduced by Dr. Holland, Application of the and the term ‘kodurite’ proposed elsewhere ERIC: in this Memoir, is only intended for the convenience of Indian geologists, and is not to be used outside the limits of the Indian Origin of the name. Cuap. XV.] GONDITE SERIES; OCCURRENCE, 307 empire for rocks, apparently of the same character and age, without very strong evidence indeed of the strict equivalence of the rocks of the two areas. Moreover, it seems desirable at present that the term should only be applied to the most metamorphosed type of mangani- ferous Dharwar rocks, namely those characterized by the development of manganiferous silicates. Of these highly metamorphosed rocks there are, as previously described, two divisions, namely the main division, characterized by the presence of spessartite-garnet and rhodonite, and the subordinate division characterized by the invariable association of manganese-ores with crystalline limestones, with the almost invariable presence of piedmontite (or possibly other manganiferous epidote). It is to the former division, characterized by the association of the manganese-ores and rocks with rocks formed by the metamor- phism of non-calcareous sediments, such as sand, clay, or conglomerate, that it is at present proposed to restrict the term ‘ gondcite’. Up to the present it has been found perfectly feasible to map separately the manganese-bearing rocks associated with a ‘country’ of mica-schist, quartzite, or gneiss, from those of which the ‘country’ is a crystalline limestone. Should later work show the impossibility of always clearly separating the two types of rocks it may then be found necessary for convenience of mapping to extend the term ‘gondite’ to the second group. In the meantime, they can be most conveniently referred to as the manganiferous limestones. The areas in which manganese-ore deposits, or rocks belonging to this series, have been up to the present located are the following :-— 1. Narukot State, im the Rewa Kantha Agency, Bombay Presidency. 2. Jhabua State, in the Bhopawar Agency, Central India. 3. The districts of Balaghat, Bhandara, Chhindwara, and Nagpur in the Central Provinces. 4. It is probable that the manganese-ore deposits that have been found in the State of Banswara in Rajputana are associated with rocks sufficiently metamorphosed to justify their in- clusion in the gondite series. Areas in which found. The principal development of these rocks is in area No. 3, which will be referred to as the Nagpur-Balaghat area, In discussing the relationships of this series with its ‘country’ it is ne- cessary to depend almost entirely on the Central Provinces. The portion of 308 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part II; this province in which this series is located is occupied by a continuous The Nagpur-Balaghgt Stretch of Archean rocks, beginning in the Chhind- area. wara district in the extreme western part of the area, and extending thence in an easterly direction through the northern part of the Nagpur district and the southern part of the Seoni district. Thence the outcrop of this Archean complex stretches to the east into the northern part of Bhandara and the western part of Balaghat. It also extends to the north into the Mandla district and to the south and south-east into the southern parts of Bhandara and Balaghat and into the Drug and Raipur districts ; but in these areas manganese-ores have not yet been located except for a doubtful occur- rence in the extreme south of Balaghat. It is in the belt of Archean rocks stretching from Chhindwara through Nagpur and Bhandara to Baldghat, that all the economically valuable manganese-ore deposits of the Central Provinces are situated. This manganiferous zone can be most conveniently designated the Ndgpur- Balaghat area. The total length of this manganiferous zone 1s about 72 miles from the Kachi Dhana deposit in the Chhindwara district on the extreme west to Jairasi in the Balaghat district on the extreme east. It is only as far as Ukua in the Balaghat district, however, that the metamorphism is known to have been sufficiently severe to bring about the development of spessartite. In fact very little is known about the occurrences to the east of this point. The strike of this manganese belt averages east-north- east. Its maximum width is 15 miles, this being at the western end ; whilst to the east of this point the width averages about 8 miles. This, however, is not, in all probability, the full width; for if the extreme northern parts of the Nagpur district, namely the forests lymg to the north of Chorbdoli, and the adjoining southern parts of Seoni district, were properly prospected there is little doubt that further occurrences of the gondite series would be found!. The Origin of the Gondite Series. With regard to the origin of the rocks of the gondite series, of which an account has already been given : (pages 289 to 293), it is intended to give now an account of their relationships to the accompanying rocks to show that the theory there put forward is in all probability the correct one. In the first published account of the manganese-silicate-rocks of the Central 1 Since this was written Mr. T. B. Kantharia has found mang: anese-ores at Koréi Ghat. This place is about 26 miles N. N. E. of Chorbéoli and in the Seoni district. Cuap. XV.] GONDITE SERIES: ORIGIN. 309 Provinces! the opinion was expressed, it is true with considerable diffidence, that the manganese-bearing rocks of this area were intruded in the molten condition into the metamorphic schists, gneisses (and quartzites), with which the manganese-silicate-rocks are associated. This was written because it was then supposed that the manganese-garnets of Vizagapatam and the Central Provinces were the same and because in both areas the manganese-ores, at least in part, have been formed by the chemical alteration of the rocks containing these garnets. It was not then thought likely that there could be in one country, large though India is, two distinct series of rocks, each characterized by the pre- sence of manganese-bearing garnets. The evidence derived from the study of the Vizagapatam occurrences in the field as exposed in the mines was so unequivocal in pointing to their igneous origin, that it was attempt- ed to make the origin of the manganese-bearing rocks of the Central Pro- vinces, which then seemed much more open to opinion agree with that of the manganese-bearing rocks of Vizagapatam. Since then, however, I have been able to make a much more careful microscopic examination of the Central Provinces rocks with the resultant abandonment of the igneous theory and a return to the theory that had first suggested itself in the field, namely that the manganese-silicate-rocks of the Central Provinces are metamorphosed sediments?. Since it has been found possible to ascribe an igneous origin to these Evidence for igneous TOCKS, even doubtéully, it will be as well to put for- origin of the gondite ward here what evidence there is for that theory. derig In the first place, as the result of a careful piece of mapping at Ramdongri in the Nagpur district, it was found that the mass of manganese-silicate-rock forming hill No. 5 forked at its eastern end. (See the map of this area, Plate 24.) Moreover, the thin band of rho- doniferous rock running east from the bank of the Kanhan river strikes straight towards the main mass of this hill and apparently disappears just before reaching it. This may be due either to faulting or to a sudden thinning out of the band. Assuming, in either case, that this thin band corresponds to the huge lenticular swelling (as seen in plan) forming the main mass of hill No. 5, it was thought that this sudden change in the width of the manganiferous band could be easily explained on the hy- oe Ree. G. 8. I., XXXII, p. 97, (1906); and Trans. Min. Geol. Inst. Ind., 1, p. 91, (1906). 2 This change of views has already been put forward in the discussion on my paper ‘Manganese in India’ in the Trans. Min. Geol. Inst. Ind. I, pp. 228-231, (1907), and in Rec, G. 8. I., XXXV., p. 39, (1907). 310 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part II: pothesis that this mass of rock was an igneous intrusion that had been compelled to conform roughly to the strike of the associated rocks by being rolled out by tectonic movements subsequent to its intrusion. The forking of the mass of manganese-silicate-rock at the eastern end of this hill could then be explained as due to the intrusive relations of these rocks to the ‘country’. [On the metamorphic hypothesis now adopted the forking would be explained as due to faulting, and the sudden swell- ing out of the manganese-silicate-rock in hill No. 5 as due to its having been originally deposited in a deep basin.| The absence of any signs of intrusive relations of the manganiferous rocks and ores towards the ‘country ’ at every place except Ramdongri might be thought to more than overbalance the evidence of Ramdongri. But the pegmatitic and granitic rocks, about the igneous origin of which there can be no doubt, occurring in association with the manganiferous rocks, are also not as a rule clearly seen to be intrusive with regard to their ‘ country ’. The general absence of felspar from the rocks of this series might have been considered sufficient to settle that they could not be of igneous origin. But this constituent is in a few cases present, although much more rarely than the macroscopic aspect of the rocks would lead one to suspect. As the result, however, of a careful microscopic examination of a large number of thin slices of the rocks collected in this area, and the consideration of the chemical evidence that has since become available, it has become clear that these rocks are, as previously explained, meta- morphosed sediments. A brief outline of the theory of their origin as thus revised is given in the two places, cited above. The evidence justi- fying this change will now be given. In the north-east parts of the Négpur-Balaghat area, namely those Evidence for meta. Parts of the Balaghat district situated to the east morphic origin of the of the Wainganga river, the manganese-ore deposits gondite series. have been mapped as occurring in the Chilpi Ghat series of rocks, whilst to the west of this river they have been mapped as occurring in the metamorphic and crystalline complex. As has already been explained the latter type of deposit is characterized by the presence of various manganiferous silicates ; whilst those mapped as occurring in the Chilpi series are sometimes free from such silicates, then containing only manganese-ores with associated and interbanded quartzites and phyllites. The key to the unravelling the relations of these two apparently different modes of occurrence of the manganese-ore deposits lies in the study of the Balégh4t and Ukua deposits, A Cuap. XV.] GONDITE SERIES: ORIGIN. 311 reference to the map of this area (Plate 43) will show that these ,, two deposits occur on one horizon, namely at The rocks at Bala- ghat and Ukua. or close to what has been mapped as the base of the Chilpis. At Balaghat the manganese-ore body consists of alternating layers of manganese-ore and red, black, and grey, vitreous quartzites. Underlying the ore-beds, and probably to be considered as a portion of the ore-body, is a variable thickness of a whitish jaspery quartzite, which often becomes so friable as to powder, when quarried, into a fine sand. This rests on a considerable thickness of schistose sericitic conglomeratic grits, which form the eastern slopes of the ridge on which the ore-band crops out. Overlying the ore-band is a great thickness of phyllites, which are often wrinkled and contorted and sometimes sufficiently crystalline to be called mica-schists. Fre- quently, on the other hand, they have not passed the slate stage. When phyllites, they are best designated sericitic phyllites. To the south- west this ore-band disappears beneath alluvium, but probably re-appears in Balaghdt town in the form of a small outcrop of manganese-ore, which I am told occurs there, but which I have not personally seen. To the south-west of this, the band again gets hidden, at least for some distance. To the north-north-east, however, the band can be traced along the ridge until it dies out, first passing into a limonitic rock. Some 10 miles to the east-north-east this band reappears at what must be its wonted horizon, namely the base of the Chilpis as here mapped. From this point the ore-band has been traced continuously through Ghondi, Gudma, Ukua, and Samnapur. I examined it in the last three village areas and made the interesting discovery that the ‘country’ of the manganese-ores is similar to that of Balaghat, but considerably more metamorphosed. The phyllites of Balaghat have here become proper crystalline mica-schists, whilst the manganese-ore band contains yellow manganese-garnet, developed, no doubt, by interaction between manga- nese oxide and interbanded or admixed argillaceous and_ siliceous materials. But the most remarkable feature of all is the rock underlying _ the ore-body. At first sight one calls this without Baccus, any hesitation ‘gneiss’, and the rock seems to be an ordinary micaceous gneiss, such as one so frequently meets with in the metamorphic and crystalline complex. But on careful examination what seem to be pebbles of white quartz 312 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part II: and granite are found weathering out at the surface of the supposed gneiss. On breaking the rock at such places it is found that the pro- jections are in truth pebbles. They are composed of various materials, white quartz, granite, and gneiss, and are set in a matrix having the ordinary mineralogical composition of a micaceous gneiss. Under the microscope this matrix is seen to be much strained and granulitized and composed of quartz, microcline, plagioclase, and biotite, with often muscovite. The conclusion that seems unavoidable is that this con- glomeratic gneiss is only a metamorphosed conglomeratic grit, no doubt very impure, equivalent to the rock of this character, already schistose, that underlies the ore-band at Bdalaghét. That such a rock can be formed by the metamorphism of an impure grit has been conclusively shown by E. H. Cunningham-Craig ' writing of the rocks of the Loch Lomond district in Scotland. He shows that albite- gneisses have been formed from the group of rocks known as the Beinn-Ledi Grits by dynamic and constructive metamorphism. We seem to have in the Balaghat district an analogous case, the only difference of note being that in the area examined by Cunningham-Craig the increas- ing metamorphism has taken place across the strike, on passing from one fold of the grits to another that has been subjected to a higher degree of pressure, and to a certain extent, temperature ; whilst in the Balaghat district the passage from grit to gneiss has taken place along the strike. We thus see that the rocks of Balaghat and Ukua can be correlated as follows :— Balaghat. Ukua. 1. Phyllites with subordinate slates and 1. Mica-schists. mica-schists. 2. Manganese-ore layers with inter- 2. Manganese-ore layers associated with banded vitzeous quartzites and bands of spessartite-quartz-rock ard occasional phyllites, of vitreous quartzites, 3. A small thickness of jaspery quartzite. 3. A small thickness cf jaspery quartzite, showing. on weathering. signs of schistosity ; not always present. 4. Schistose conglomeratic sericitic grit. 4. Schistcse micaceous gneiss often con- taining pebbles of quartz, granites, and gneiss. This rock passes downwards into less schistose gneiss. The gneiss underlying the manganese-ore band at Ukua would ordinarily get mapped as distinct from the Chilpis and as a part of the metamor- 1 Quar. Jour. Geol. Soc., LX, pp. 10-28, ( 1904). Cuap. XV.] “ GONDITE SERIES : ORIGIN. 313 phic and crystalline complex; in fact such has been the fate of this very occurrence at the hands of previous workers in this area. Yet the grit un- derlying the manganese-ore deposit at Balaghét must undoubtedly be regarded as a part of the Chilpi series. On the west side of the Wain- ganga the whole of the metamorphic and crystalline complex has been mapped as a single formation both by me and by Mr. Datta, except for the big range of quartzites running in a general south-westerly direc- tion through Chandpur and Ambagarh in the Bhandara district. But if time could be found for a detailed survey of this area, on maps of a large scale where such are available, it would be possible to distinguish a large number of outcrops as the highly metamorphosed equivalents of the Chilpis. The quartzites and mica-schists can probably be regarded as such and could easily be distinguished ; but when it came to deciding which gneisses are to be regarded as metamorphosed sedimentaries or para-gneisses, and which are metamorphosed igneous rocks or ortho- gneisses, the work would have to be controlled and checked by a con- siderable amount of chemical analysis. That portions of this complex can fairly be regarded as the metamorphosed equivalents of the Chilpis is indicated by a very interesting microscopical feature of the mica- ee schists. On the low ground to the east of Sita- phyllites of Bhandara sdongi HillI collecteda specimenof a very coarse- ere grained silvery mica-schist. Under the microscope the rock is seen to contain—besides muscovite, quartz, and a certain quantity of felspar—a number of tiny perfectly idiomorphic lavender- coloured tourmalines, a considerable quantity of ottrelite noticeable as green specks in the hand-specimen, and lastly an abundance of small idiomorphic crystals of composite character. They are partly opaque black, suggesting an iron-ore such as magnetite or ilmenite, and partly transparent yellow, corresponding in all respects to rutile.’ Sometimes the boundaries between the iron-ore—which from its association with rutile is in all probability iimenite—and the rutile are quite irregular ; but more frequently the two minerals are arranged in bands, correspond- ing in all probability to twinning planes of the rutile; and the slide suggests that these composite grains were originally entirely rutile and 1 The presence of considerable amounts of titanium jn the Sitasdongi, Balaghat. and Ukua, schists and phyllites has been proved by Mr. T. R. Blyth. Mari 314 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part Il: that they have since been partly converted into ilmenite. An alternative view is that the structure is original and due to an intergrowth of these two minerals during the metamorphism of the sediments from which this rock was presumably derived, their arrangement being determined by the strong tendency to twinning possessed by rutile. This rock was collected in a region where all the rocks are so highly metamorphosed that one would not at first suspect the presence of the Chilpis. The interest and importance of this rock lies in the fact that the phyllites occupying the ridge immediately to the west of the Balaghat ore-ridge are found, although usually much less coarsely crystalline, to show exactly the same minerals as the Sitasdongi rock : so that it would often be impossible to separate the slides prepared from the rocks of the two localities once they had become mixed. This extraordinary likeness extends even to the structure of the complex rutile-ilmenite grains. In this neighbour- hood there is, of course, no doubt that these phyllites belong to the Chilpie Ghat series. Hence there can be little doubt that the Sitaséongi rock also belongs to the Chilpi series, although it is in a more meta- morphosed region than at Balaghat. But it must not be supposed that all the Chilpi phyllites and mica-schists are petrologically precisely the same as the rock described above. Thus, of some specimens of mica-schist collected from the Chilpi area near Ukua, one specimen shows the tourmaline and ottrelite, but not the composite rutile- ilmenite grains. Instead of the latter it contains scattered grains of a black iron-ore round each of which there is a beautiful halo of red hematite. Whilst another specimen from the same locality contains, in addition to the usual constituents, sphene and colourless garnet(?). Similar interesting comparisons could easily be made between other rocks of the Chilpis and metamorphic and crystalline series, respec- tively, but none of them are so striking as the example given above. When one comes to examine the ‘ country’ of the gondite series it at The ‘country’? of once becomes evident that the rocks most closely the gondite series. associated with the manganese-bearing rocks and ores are mica-schists, quartzites, and more rarely schistose gneisses, which are usual y very siliceous. Rarely, in fact practically never, are the rocks of tne gondite series closely associated with hornblende-schists, crystalline limestones (I am referring here, of course, to the manganese bearing rocks free from piedmontite), or gneisses of igneous origin. This Cuap. XV a] GONDITE SERIES : ORIGIN. 315 one would not expect were the gondite rocks of igneous origin, as there is no apparent reason why they should always have chosen rocks of original sedimentary origin into which to intrude themselves. For the quartzites and para-gneisses are not any less strong structurally than the hornblende- schists, ortho-gneisses and crystalline limestones. Moreover, why should the manganese-bearing rocks associated with the crystalline limestones almost invariably contain piedmontite, with spessartite and rhodonite as a rule absent, or only present in small quantity ; whilst the manganese. bearing rocks associated with the mica-schists, quartzites, and para- gneisses, are characterized by the almost invariable absence of piedmon- tite and the frequent great abundance of spessartite and rhodonite ? The only explanation that seems to meet the case is that the manganese- bearing rocks were deposited as sediments with the rocks with which they are associated, so that they partake to a certain extent of the chemical composition of the enclosing rocks. Miacacchetcae an The conclusions that it seems legitimate to to origin. draw from the preceding paragraphs are :— (1) That the portions of the metamorphic and crystalline complex with which the manganese-bearing rocks of the gondite series are associated in the districts of Chhindwara, Nagpur, Bhan- dara, and Balaghat, are the more highly metamorphosed equi- valents of the rocks that have been designated the Chilpi Ghat series in the Balaghat district. (2) That the manganese-bearing rocks are not intrusive in these metamorphosed sediments, but have been formed by the metamorphism of manganese-bearing sediments deposited contemporaneously with the sands, clays, and impure grits, from which these quartzites, mica-schists, and gneisses, have been formed. It should be noticed that there is nothing in the mineral com- position of the rocks and ores of the gondite series that seems in the least repugnant to this theory that they are metamorphosed sediments, The question naturally arises as to the shape of the masses of water The shape of the in which the manganiferous sediments were areas of deposition. deposited. A reference to the map (Plate 43) of this area will show what a large number of outcrops of the rocks and ores of the gondite series have been found. It will also be seen that the form these outcrops assume is that of long bands. In a few cases these bands can be traced until they die out in lenticular fashion. As good il ¥ 2 316 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part II: examples may be cited the Gaimukh deposit (fig. 47, p. 782) in the Chhind- wara district, the Kandri deposit (Plate 32) in Nagpur, and the Balaghat deposit. Of these the Gaimukh deposit terminates thus at both ends, the Kandri deposit at the south-east end in South Hill and the Balaghat deposit at its northern end. But in the majority of cases the termina- tion of the deposit in either direction is hidden by soil or jungle, and as these deposits are often arranged in strings so that the strike of one if produced would carry it into another a mile or two away in the direction of the strike, it is not possible to say if this lenticular thinning out is the tule or not. One would suspect that in many cases the ore-band is continuous between many of the so-called separate deposits and that it only needs the uncovering of the intervening ground, no doubt in many cases to a considerable depth, to demonstrate this continuity. An example is the string of deposits in the Nagpur district stretching in an average west to east direction from Dumri Kalan on the west, through Satak, Beldongri, Nandapuri, Lohdongri, Kacharwahi, and Waregdon, to Khandala on the extreme east. All these deposits, except Khandala, are situated in the alluvium, and very little or no rock is to be seen in the ground between the separate deposits, everything being obscured by alluvium. The mere fact that the majority of the deposits lie along fairly well The number of ore- defined lines would at first sight be taken as horizons. indicating that they correspond to one bed or horizon that has been folded, so that its edges have come to the surface along several more or less linear outcrops. And the fact that the deposits known to occur in the portions of the Chilpis that are only moderately metamorphosed, lie at a horizon that may be regarded as being near the base of this series, might be taken to indicate that the manganese-ore deposjts correspond to a definite horizon near the base of the Chilpis, the conglomeratic grit underlying the manganese-ore horizon at Balaghdt being possibly the base of this formation. The truth of such a hypothesis cannot at present be either proved or disproved; it would need a very close piece of work, involving the very careful correlation of the various beds of rock, in both the Chilpi and crystalline areas, to settle the question. The mere fact that there are apparently several parallel bands of deposits in the crystalline portion of the Nagpur-Baélaghét area might be thought to be opposed to the idea that there is only one ore-horizon in this area. It must be remem- bered, however, that the deposits situated in the more metamorphosed areas owe their more crystalline character to the fact that the more Cuap. XV] GONDITE SERIES : ORIGIN. 317 deeply buried portions of the folds into which the Chilpis were thrown at the end of the period of sedimentation have here been exposed by the denuding agencies of nature. Were two horizontal sections to be constructed across a series of folded beds of rock at two levels, the one nearer the surface might only cut a certain bed, such as a layer of manga- nese-ore for example, twice, namely, on the two outer edges of the fold. But at a lower level towards the base of the main trough formed by the fold, the simple fold would probably be complicated by a series of minor folds. This crinkling of the base of the trough would cause a line of sec- tion near the base to cut the ore-layer several times. Thus in figure 21, a Fig. 21.—Ideal section across a syncline of manganiferous rock. section at the level AB would only cut the ore-layer in two places, namely, A and B, and the manganese-ore body would be of the less metamorphosed type like that of Balaghat. But a section at the level CD would cut the ore-layer several times, in the figure 6 times, and the ore-layer would be of the highly metamorphosed type like those of the metamorphic and cry- stallme complex!. From this it is evident that the fact that there are several roughly parallel ore-bands in the more metamorphosed portions of the Archean complex of this area does not conflict with what would be expected if there were only one ore-horizon. This does not, however, obviate the fact that the existence of several ore-outcrops could also be explained by the actual existence of several ore-horizons. I do not here give a definite expression of opinion one way or the other, except to say that it certainly seems more probable that the repetition of the ore-bands in the more metamorphosed parts of this area is due to the bringing of a 1 Rocks that were only buricd to the depth represented by the line AB possibly did not get below Van Hise’s upper zone of katamorphism ; whilst rocks that reached the depth represented by the line CD probably entered Van Hise’s lower zone of anamorphism. 318 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part II: fewer number of ore-bands to the surface than the total number of lines of outcrop, especially in view of the fact that only one ore-horizon has been yet discovered in the true Chilpi areal. Admitting, then, that the outcrops of manganese-bearing rocks and ores correspond to only a small number of original beds of ore, the question again arises as to whether the deposition of ore over a particular horizon was continuous, 7.e., whether the manganese oxides were laid down as a continuous sheet ; or whether they were deposited in a patchy fashion, such as would be the case were the deposition taking place in a series of basin-like areas, such as a series of lagoons or lakes. At first sight it would seem evident owing to the discontinuity of the ore-bodies situated along one line of outcrop that the latter theory is the correct one. But as ex- plained above, this interruption in the continuity of one particular outcrop may only be apparent and due to the obscuring of the intervening ground. In some cases, however, it is real, namely those in which there can be no doubt that the ore deposit is of lenticular shape and definitely dies out in lenticular fashion in a comparatively short distance. This interruption might, of course, be explained as due to the squeezing out of a previously continuous bed into separate lenticular portions under the influence of the severe tectonic disturbances to which these rocks were subjected. Fortunately, however, one of these cases of lenticular thinning out occurs at Balaghdt, where the degree of metamorphism to which the ore-layer has been subjected could not be regarded as in any way adequate to account for such a squeezing out. It thus seems as if we can say with Devotions) ieseen oe degree of certainty that these manganiferous place in lagoon- or sediments were partly deposited in circumscribed Pree areas of the nature of lagoons or lakes and that they were partly deposited in areas of considerable extent such as a compara- tively large lake.? One feature that is worth noting is that the ending of some of these areas is very sudden. Thus the south-east end of the ore-band in South Hill at Kandri, as seen in level No. 1, is about 70 feet across, and in the course of a few yards the band is rounded off and suddenly disappears Some ore-lenticles beneath the surface. If this be a deposit that was due to squeezing and Griginally laid down in a basin having this shape some to deposition in basin-shaped areas. before it was subjected to the tectonic movements characterizing the termination of the Dharwar period of sedimentation, 1 Ses the account of the Thirori deposit, page 699. 2 [ am discussing in this place the Nagpur-Baélaghdt area only ; there is of course little doubt that the ores deposited in Dharwar times in other parts of India, such as Jhébua and Narukot, were deposited in separate areas of deposition. Cuap. XV.] GONDITE SERIES IN JHKABUA, 319 then the shape of the original basin must have been a somewhat curious one, with very steep banks. This might mean that the basin was one abutting against a hill remaining from the pre-Dharwar land surface ; but it more probably means that the shape of the original basin has been distorted by the earth movements to which it has been subjected. Another example of this very rapid thinning out of the manganese ore band is the Gaimukh deposit, a rough sketch of which is given on page 782. If we explain this sudden thinning out of certain deposits in the way suggested above, namely as due to distortion during tectonic movements, then it is difficy!t to avoid the supposition that in at least a few cases the pressure has beea sufficient to squeeze out the ore-bands into separate lenticles. The formation of a few separate lenticles in this way is not to be taken as negativing the explanation given above of the shape of the bodies of water in which the manganese-ores were laid down, but rather as modifying that explanation slightly. It is obvious that if it be the case that there is a manganese-ore peeeecotee » for horizon situate near the base of the Chilpi series, manganese-ore at the it ought to be possible to make use of this fact, and base of the Chilpis. in fact to test it, by carefully prospecting along the lines that are marked in the map of this area (Plate 43) as bounding the Chilpi series from the remainder of the Archean complex. The region especially favourable for this purpose is, of course, the southern portion of the Balaghat district and the adjoining parts of the Bhandara district. The Gondite Series in Jhabua. The occurrence of the rocks of the gondite series that I was able to examine at K ajlidongri in Jhabua State, Central India, and which, as has already been noticed on page 283, is enclosed in rocks that are to be re- garded as a southern extension of Aravalli system of Rajputana, is very similar to the occurrences of this series in the Central Provinces. It is folded up with rocks that may variously be called phyllites or mica- schists, according to the stage of re-crystallization they have reached. The ore-body itself consists of layers of manganese-ore interbanded with red vitreous quartzites identical in all respects with the red quartzites that occur in the ore-body at Balaghat. This red quartzite is very fine- grained and is seen under the microscope to owe its colour to clouds of minutely divided red dust collected in clouds in the interiors of the grains of quartz. These clouds are usually centrally disposed in their respective 320 MANGANESE DEPOSITS OF INDIA : GEOLOGY. [Parr II: quartz grains and doubtless consist of ferric oxide. The absolute identity of the quartzites from these two widely distant manganese-ore deposits is eloquent testimony to their having been formed under the same conditions, and is about as good a proof of the identity of the Chilpi Ghat and Aravalli series as could well be found; provided that the continuity of the supposed Aravalli rocks of Jhabua with the typical Aravallis of Rajputana be once proved, as no doubt it will be one day. In respect to the degree of metamorphism that the ‘country’ and the interbanded quartzite layers of this deposit have suffered, this deposit may be regarded as the equivalent of the Balaghat deposit of the Central Provinces. It has, however, been considerably more metamorphosed, as is shown by the presence of spessartite and rhodonite in various parts of the deposit and by the fact that there is a considerable amount of braunite present. In this deposit, moreover, the manganiferous am- phibole and pyroxene, winchite and blanfordite, respectively, have been developed; as well as a crimson manganiferous mica. Further, the manganese-epidote, piedmontite, has also been formed in the ‘country’ of this deposit ; this being the only occurrence of piedmontite that has yet been found in India outside the crystalline limestones, with the exception of the occurrence at Jothvad noted in the next section. The Gondite Series in Narukot. One occurrence of the rocks of the gondite series has also been found at Jothvad in the Narukot State, Rewa Kantha Agency, Bombay Pre- sidency. This occurrence is associated with rocks which have reached at least the same degree of metamorphism as those characterizing the rocks of the metainorphic and crystalline complex of the Central Provinces. The whole series of rocks has been intensely folded, and intruded by a porphyritic biotite granite, which from its mineralogical and petrogra- phical characters may be regarded as the equivalent of the Bundelkhand granite of Central India. Apophyses are seen to start from this granite and penetrate the series of banded and folded rocks constituting the main mass of the hill in which the manganese-bearing rocks occur, and in these apophyses or granite eins various interesting minerals, charac- terized by the presence of a vertain quantity of manganese, taken up no doubt from the manganese-hearing rocks at the time of their injection into the gneissic series, have crystallized out. The most interesting feature of the occurrence lies, however, in the fact that in one spot, namely at the junction of the main mass of the granite with the gneissic series, the Cuap. XV.] GONDITE SERIES IN NARUKOT. 321 granite contains inclusions of various of the rocks of the gneisses series (see Plate 17). Amongst the rocks so included are some of the mangani- ferous varieties, both manganese-silicate-rocks and crystalline manganese- ores. In some cases these ores seem to have been formed by the alteration of the manganese silicates ; but in the majority of cases they were formed at the time of the metamorphism of the manganiferous sediments, by the compression of the manganese oxides, with absorption of the small amount of silica required for the formation of braunite in accordance with the equation given on page 290. In so far as any portions of the ore found in these masses of rock included in granite can be Alteration of man: Clearly distinguished as having been formed by the ganese silicate to alteration of the manganese silicates, they may be eee Aceon regarded as evidence that the formation of the times. manganese-ores from manganese-bearing silicates took place before the intrusion of this granite, that is in all probability in Archean times. And as the manganese-bearing rocks of this hill are suffi- ciently like those of the Central Provinces to justify the supposition that they were formed at the same time and under similar circumstances, it seems justifiable to extend this piece of information to the rocks of the Central Provinces and suppose that there also at least a portion of the alteration of manganese silicates into manganese-ore took place in Archean times. Although the rocks of this hill are many of them very similar to those occurring in the gondite series in the Central Provinces, yet they are some- what different owing to the frequent presence of apatite in considerable abundance. A reference to the description of this occurrence of manga- nese-bearing rocks on page 330 will show the great variety of these rocks, containing as they do the following manganiferous minerals :— spessartite, rhodonite (?), piedmontite, manganese-mica, manganiferous pyroxene showing the blanfordite type of pleochroism, and another pyroxene also probably containing manganese. Since some of these manganiferous rocks contain felspars, a rather unusual mineral in the gondite series, it is evident that, if the rocks were formed from sediments, these sediments must have been, in at least some cases, felspathic. Also, from the fact that some of the manganese-bearing rocks contain calcite, it is evident that the sediments were often calcareous. The other constituents point to the presence of quartz and clay in the original sedi- ments. The various banded rocks associated with the manganese-bearing rocks are also of somewhat unusual character, and if they were formed by 322 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [ Part IL: the metamorphism of sediments, as they must have been if these rocks are co be correlated with the rocks of the Central Provinces, these sediments -1ust have been more impure and more varied than usual. The chaleo- pyrite found in one of them must have been subsequently introduced. CHAPTER XVI. GEOLOGY—continued. The Gondite Series—continued. Mineralogy—Petrology—N omenclature—Structure—Lists of rocks—Descriptions of rocks—List of localities—Areas to prospect. Mineralogy of the Gondite Series. The following minerals have been found in the rocks and ore-bodies of the gondite series of the Central Provinces, Jhabua, and Narukot :— Last of minerals found in the rocks and ore-bodies of the gondite serves. Albite Oligoclase Amphiboles Orthoclase Apatite Opal Arsenates Piedmontite Barytes Plagioclase Beldongrite Psilomelane Blanfordite Pyrolusite Braunite Pyrophanite(?) Calcite Pyroxene (pale green) Chalcedony Quartz Halite. Rhodochrosite Hematite Rhodonite Hollandite Rutile Limonite Scapolite Magnetite Sitaparite Manganese-amphiboles Spessartite Manganchlorite ? Sphene (?) Manganesian phosphate Tale Manganmagnetite Tremolite Manganese-micas Vredenburgite Manganese-pyroxenes Winchite Microcline Wollastonite In veins traversing the rocks and ores of this series the following mine- rals have been found :— List of minerals found in veins piercing the rocks and ores of the gondite serves. Arsenate of Mg., etc. (Kajlidongri). Barytes (K4jlidongri). Hematite. Limonite (Kodegaon). Psilomelane. Pyrite (Kodegéon). Quartz. Hollandite (K4jlidongri). 324 MANGANESE DEPOSITS OF INDIA: GEOLOGY, [Parr IL: In granitic, pegmatitic and felspathic intrusions, usually in the form of veins, piercing the rocks of the gondite series the following minerals have been observed :— List of minerals jound in rocks intrusive in the gondite series. Albite. Amphibole (lilac). Apatite. Biotite. Blanfordite (Jothvad, Ramdongri, and Kae » Braunite (Kacharwahi and Satak). Carpholite ? Greenovite (Jothvad). Juddite (Kacharwahi). Manganese-garnets. Microcline. Microperthite. Oligoclase. Orthoclase. Plagioclase. Pyroxene (brown) (Kusumbah). Quartz. Sphene. Tourmaline. Zircon. As will be seen from the lists given above, many of the minerals in both the intrusives and the mineral veins are characterized by the presence of either small or large quantities of manganese, which often impart to the mineral its distinctive properties. This manganese has, no doubt, been obtained from the rocks of the gondite series through which the molten rocks or heated waters, as the case may be, have passed. It is not known whether one of the rocks, namely one composed of quartz, carpholite (?), and oligoclase-albite, is an intrusive ora mineral vein. From the fact of the presence of felspar it might be thought to be obviously an intrusive. But it is now well recognized that felspars are not infrequently formed in true mineral veins. It has, however, been considered here as an intrusive. In the first list given above only those minerals are mentioned that are found right in the masses of manganese-silicate-rock or in the actual peripheral zone of the deposit. In Dharwar times the sediments deposited both before and after the manganiferous sediments proper must often have contained small quantities of manganese ; so that when the rocks were metamorphosed some of the rocks thus produced often contained small quantities of manganese-bearing minerals, without in any way form- ing part of the ore-body. Such slightly manganiferous sediments tend, of course, to occur close to the manganiferous rocks and ores, because the change from the conditions under which non-manganiferous sediments Cuapr. XVI] GONDITE SERIES: PETROLOGY. 325 were deposited to those under which the manganese-oxide sediments were laid down cannot have been quite sudden. Amongst the minerals con- taining manganese that occur in the ‘country’ of the deposit as dis- tinct from the deposits themselves, are the following :—manganese-garnet, manganmagnetite, and ottrelite ; whilst psilomelane and pyrolusite are often formed in the ‘country’ by secondary infiltration of manganese- bearing solutions from the ore-body. The following is a full list of the minerals recognised in the ‘country’ of the masses of manganese-silicate rock and manganese-ore :— List of minerals found in the rocks forming the ‘country’ of the manganese- ore deposits. Apatite Muscovite Biotite Oitvelite Braunite(?) Piedmontite Calcite Plagioclase Chalcopyrite Psilomelane Chlorite Pyrolusite Diopside Quariz Enstatite(?) Rutile Epidote Sapphirine Garnet Scapolite Hematite Sericite Hornblende Spessartite Iimenite Sphene Magnetite Tale Manganmagnetite Tourmaline Martite Wollastonite Microcline Zircon Petrology of the Gondite Series. We can now deal with the question of the nomenclature of the rocks Nomenclature of Of the gondite series. The type rock is one composed the gondite series. practically entirely of 2 manganese-bedring garnet approximating in composition to spessartite, and of quartz. The garnet occurs as a large number of tiny round grains set in a matrix ot mosaic quartz, the grains of which are usually of about the same size as the garnet grains. The rock appears to the unaided eye as a very fine- grained rock of which the structure just seems visible. The characters of this rock will be given in more detail later. This is, however, the rock to which it is proposed to give the name gondite. Similar rocks have pro- bably been found in the metamorphic rocks of other parts of the world, e.g. in Texas’; but I am not aware that any name has ever been given to such rocks. Probably they have not previously been found in 1 Penrose, An. Rep. Geol. Surv. Arkansas for 1890, Vol. I, Chap. XVI. 326 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Parr th: sufficient quantity for the need for such a term to be felt. The nearest rock to gondite seems at first sight, on account of the spessartite present, to be that to which the name queluzite has been given by Dr. Orville Derby; but, as will be judged from page 274, this rock is really considerably different to gondite, and more closely related to kodurite, one of the chief points being that it is supposed to be of igneous origin. To varieties of the spessartite-quartz-rocks of coarser grain the name gondite may also be extended, but such rock is not to be regarded as the typical rock. Under this extended meaning of the term some varieties of gondite will possess quite a coarse-grained structure, the garnets sometimes being as large as an inch in diameter.’ Very often the manganese-silicate rock consists entirely of garnet, the quartz being absent. It will then be known as spessartite-rock. When the rock contains important quantities of apatite, as at Jothvad in Narukot, the rock is an apatite-gondite. Spessartite-quartz-rock containing rhodonite is rhodonite-gondite. It is not proposed to introduce any special name for the rocks rich in rhodonite, because rhodonite is a much less common mineral than spessartite in the rocks of this series. The rock found at many localities, composed entirely of rhodonite, will therefore be known as rhodonite-rock. There may be a small quantity of manganese-garnet present, which may increase in quantity until it predominates over the rhodonite. The rock then becomes rhodonite- spessartite-rock or rhodonite-gondite, according as quartz is absent or present. Sometimes the rock contains a brownish to greyish radiate fibrous mineral that is probably an amphibole. Such a rock would be termed an amphibole-gondite. Occasionally scales of a manganiferous mica may be present in the spessartite-quartz-rock. The rock is then a mica-gondite. The other rarer rocks found in this series, such as the garnet-rhodonite rock containing barytes and a manganesian phosphate, found at Chargdon, Nagpur district, will be known by the names of their constituents. There are many other varieties of rocks in this series ; but it is not necessary to explain the meaning of their names as given in the complete list on page 329; they are self-evident after the foregoing explanation. Before proceeding to give a brief account of the petrology of the rocks SiidivBaEE tha Denes Oe gondite series, it will be necessary to give a of manganese-bearing Short account of the structure of the bodies of ore rocks. and manganese-bearing rocks. Except when the ore-bodies are composed entirely, or practically so, of manganese-ore, they usually exhibit a banded structure due to the alternation of layers of CHap. XVI. ] GONDITE SERIES: PETROLOGY. 327 different composition. Some of these layers, and in many cases nearly all of them, consist of rocks containing a high percentage of manganese, and are consequently largely composed of manganese-bearing minerals. The typical rocks in these manganiferous bands are gondite, spessartite-rock, rhodonite-gondite, rhodonite-spessartite-rock, and rhodonite-rock, and the manganese-ores, either original or formed by the alteration of the manga- nese-silicate-rocks mentioned above. As partings to these manganiferous layers are various rocks that either contain only a small amount of manganese or are practically free from thiselement. The commonest of these parting layers are quartzites of various colours and texture, their characters depending to a large extent on the nature of the impurities that the sands from which they were formed contained before they suffered metamorphism. Thus the quartzite may be red from the presence of ferric oxide, black from the presence of manganese-ores, or light grey or even white, owing to the comparative purity of the rock. Or again, the impurities may have crystallized out as definite minerals giving rise to pyroxenic quartzites, spessartiferous quartzites, and so on. In other cases the impurities have given rise to various mica-quartz-schists and mica-schists, in which the mica often shows unusual types of pleo- chroism owing to the presence of small quantities of manganese. Again at the periphery of many of the masses of manganiferous rocks various interesting rocks are often found that have either been formed by an interaction with the manganiferous sediments, or have been produced by the metamorphism of sediments that contained considerable quantities of manganese, but not enough to make the rock a portion of the ore- body. Such rocks often contain manganiferous pyroxenes, garnets, micas, and amphiboles. ' Inthe ore-body the rocks are, as has been mentioned above, usually ar- ranged in bands. These bands are often of quite small thickness. Thus a rock may consist of layers of gondite and quartz, only $ an inch to an inch thick; or one layer of gondite or of rhodonite-rock may be as much as 1, 2, or even 3, feet thick. On the outcrop, these banded rocks, if they have not been largely altered with formation of manganese-ore, often show differential weathermg. Thus a layer of quartz may stand up leaving the alternating layers of gondite occupying slight depressions. Owing to their mode of formation, namely by the metamorphism of sediments, the masses of manganese-bearing rocks and ores naturally appear to be definitely bedded, although, owing to the,fact that these sediments were deposited in basin-like areas, or because they have been 328 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [ Part II: subsequently squeezed out, they tend to change in thickness along the strike, with an ultimate thinning out of the mass of rock. Moreover, as one would expect in the case of rocks that have been subjected to great tectonic influences, these beds of rock are often folded so as to cause a duplication at the surface of the outcropping bands of rock. In some cases, such as at Madnegaon (page 944), this fact of two outcropping beds of ore joining together below the surface has been definitely proved by the work carried out in the opening up of the deposit. In others it is to be inferred. Thus at the time of my visit in 1904 to Thirori there were apparently five distinct outcropping bands of ore. I am told that subsequent work at this place has shown that a part of this multiplicity of ore-bands is due to the folding of one bed of ore. One cannot say, of course, if all the cases of two or more parallel ore-bands are due to the folding of a single bed of ore. There is no @ priori reason why there should not be at any one place two or more parallel beds of ore or manganese-silicate-rock. Owing to the fact that these beds of ore and manganese-silicate-rock Dip of th> bands of have been folded, they are usually found to dip at the gondite series. steep or moderately steep angles, although a small dip is also sometimes encountered, especially at the summit of an anti- clinal fold, as at Panchala ; or as at Pachara, where the whole bed of ore seems to be nearly horizontal. The masses of manganese-bearing rocks and ores often attain great Dimensions of the dimensions. Thus the Balaghat deposit is 1? miles masses and bands of long; at Manegdon the ore-body is 13 miles long; ie eon the ore-band running from Ghondi through Gudma and Ukua to Samnapur must be at least 4 miles long ; whilst at Thirori the ore-bands can be traced for about 6 miles. If, however, any of the lines of deposits represent a continuous run of manganiferous rock be- neath the surface then the ore-band must be in some places at least 10 miles long, as for example in the continuation of the Thirori ore-band towards the north-east through Chaukhandi and Chikmara. In breadth the bands of the gondite series and associated ores may be of very small thickness, such as 2 or 3 feet as at Wagora. Or they may be of great breadth. Thus the true thickness of the ore-band at Mansar is about 50 feet at its thickest portion, where it in some places consists almost entirely of ore, whilst at Ramdongri the lenticular mass of ore and spessartite-bearing rock measures about 1,500 feet across at its greatest width. This enormous thickness may, however, be due to the compression together of two or more fglds of the manganese-bearing rocks, although there is no evidence to show that such is the case, Cuap. XVI. ] GONDITE SERIES: PETROLOGY, 329 Lists of Rocks. Space will not permit me to give in this Memoir a detailed account of the petrological characters of these rocks ; so that I propose to first give a classification of the various rocks that have so far been found in these masses of manganese-bearing rocks and ores, and then to give short petro- logical accounts of the commonest and most characteristic varieties. The following list gives a classification of the rocks found up to the present in the gondite series. From this list, however, the rocks containing manganese-ores have been omitted, because it is impos- sible to decide which of them are to be regarded as the direct product of the metamorphism of the original manganiferous sediments and which have been produced by the chemical alteration of the manganese-silicate- rocks. The parting layers of quartzites and micaceous schists separating the layers of manganese-silicate-rock have also been omitted from this classification, because they will be given in a separate list later on. List of the rocks found in the gondite series as represented in the Central Provinces. With quartz. Gondite Rhodonite-gondite Apatite-gondite Amphibole-gondite Amphibole-rhodonite-gondite Amphibole-apatite-gondite Magnetite-gondite Rhodochrosite-gondite Orthoclase-gondite Microcline-gondite Pyroxene (brown)-micr-cline- gondite Orthoclase-amphibole-rhodonite- gondite with rhodochrosite (?) Rhodonite-quartz-rock Without quartz. Spessartite-rock Rhodonite-spessartite-rock Apatite-spessartite-rock Amphibole-spessartite-rcck Amphibole-spessartite-rhodounite- rock Magnetite-spessartite-rock Rhodochrosite-spessartite-rhodonite rock Rhodochrosite-rhodonite-rock Spessartite-orthoclase-rock Apatite-felspar-spessartite-rock with mica Rhodonite-rock Rhodonite-rock with magnetite, spessartite, and manganese-mica Barytes-spessartite-rhodonite rock Barytes-spessartite-rhodonite-rock with a manganesian phosphate IL G 330 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part its: Owing no doubt to the fact that practically only one occurrence of the gondite series has been examined in each of the other two areas where this series has been found, many of the rocks found in the gondite series as represented in the Central Provinces have not been found in Jhébua or Narukot. Whilst, owing probably to original differences in the com- pesition of the sediments deposited in these two areas, many rocks are found in them that have not been found in the gondite series as represented in the Central Provinces. In the Central Provinces the calcareous manganese-bearing sediments that gave rise to the piedmontite-limestones were deposited separately from the practically non-calcareous sediments from which the typical gondites were pro- duced ; whilst in Ndrukot the calcareous and non-caleareous manga- niferous sediments were deposited in alternating layers, so that, now that they have been metamorphosed, the typical rocks of the gondite series are found associated with rocks that it is necessary to consider as a part of this series, but which are to be regarded as an abnormal development of the series. In the same way in Jhdbua, as represented by the one deposit at K4jlidongri, the original manganese-bearing sediments must have been largely of the type that gave rise to the typical rocks of the gondite series of the Central Provinces with occasional layers of more calcareous nature. The following isa list of the rocks of the gondite series as represented in ‘the K 4jlidongri deposit in Jhabua State :— List of the recks found in the gondite series as represented in Jhabua. Gondite Spessartite-rock. Apatite-gondite. Apatite-spessartite-rhodonite-rock. Rhodonite-a patite-quartz-pyroxene(yellow)-rock with some spessartite Quartz-plagiclase-spessartite-piedmontite-rock. Braunite-spessartite-quartz-arsenate- rock. Amphibole-pyroxene ( yellow)-quartz-rock Whilst the following list shows the rocks found in this series as represented in Narukot State, Bombay :— List of the rocks of the gondite series as represented in Ndérukot. Gondite. A patite-gondite Pied ontite-apatite-gondite with a little pyroxene. Piedmontite-apatite-spessartile-rock. Pyroxene (yellow)-apatite-gondite. Calcite-gondite with pyroxene, apatite, and wollastonite. Rhodonite(?)-pyroxene(vellow)-gondite. Calcite-rhodonite(?)-pyroxene(yellow)-gondite. Pyroxene(yellowish)-gondite with calcite Calcite-gondite with pyroxene, apatite, and wollastonite. Wollastonite-apatite-calcite-gondite (or crystalline limestone). Piedmontite-wollastonite-apatite-calcite-gondite, Cuar. XVI.] GONDITE SERIES : PETROLOGY. 331 As has been mentioned on a previous page (294), although it is thought Rocks of the gondite that a considerable proportion of the manganese- series containing : 5 brenite: ~ ores associated with the rocks of the gondite series has been derived from these rocks by their chemical alteration, yet a considerable proportion of the ores has been in all probability formed direct from the original manganiferous sediments, whenever they were deposited practically free from admixture with other sediments, such as sand or clay. It is now not possible to determine what proportion of the ores have been formed in these two ways. Consequently in the lists, given above, of the rocks of the gondite series, the members containing original manganese-ores have not been included. The lists might therefore be considerably extended by adding many varieties containing braunite ; but it would not be certain that all these rocks were the direct products of the metamorphism of original sediments. Thus some of the rocks composed of braunite and spessartite may be the original products of metamor- phism, whilst others may have been originally composed entirely of syessartite and owe their braunite to subsequent chemical changes. In the case of the gondite series in the Central Provinces the varieties con- taining original braunite are more likely to be those that can be formed by adding this mineral to the rocks given in the right-hand column on page 329, 7.e. to those free from quartz, than those formed by adding it to the rocks shown in the left-hand column, 7.¢. to those containing quartz. For in the latter case the tendency during metamorphism would have been for the constituents that might have given rise to braunite to com- bine with a further quantity of quartz with the production of rhodonite. Thus, on account of the possibility of the reaction expressed by the following equation, one would expect any braunite, if formed, to pass in the presence of free silica into rhodonite :— 3M2203.MnSi03 + 6810, = T7MnSiO3 + 30. Braunite Quartz Rhodonite. If, however, during the metamorphism of the manganiferous sedi- ments some braunite were formed and enclosed in spessartite or rhodonite, it might be preserved ; so that one would expect to find ome cases of rocks containing both quartz and braunite, if only the br: unite were enclosed in another mineral, such as spessartite, which would protect it from the quartz. Such cases are frequently found. Moreover, it sometimes hap- pens that these manganiferous rocks contain these two minerals in direct contact in such a way that they must have been originally formed in tkis position at the time of the metamorphism of the original sediments. A 332 MANGANESE DEPOSITS OF INDIA: GEOLOGY. {Parr II: case in point is the winchite-braunite-calcite-quartz-rock or winchite- schist of Kajlidongri, in which the braunite grains are idiomorphic in shape, taking the form of tiny octahedra, which are enclosed in all the other minerals in such a way that there can be no doubt that they were formed at the time of formation of the schist by the metamorphism of the sediments from which they were derived. As has already been mentioned, the rocks of the gondite series, i.e. those enumerated above, occur interbanded both one with another and with various quartzites and micaceous schists, many of which differ from ordinary quartzites and schists on account of their manganese contents. The following is a list of the rocks occurring interbanded with the man- ganese-silicate rocks and manganese-ores of the Centr-! Provinces :— Inst of the rocks interbanded with the rocks of the gonu-.. cries in the Central Provinces. Quartz-rock. White quartzite. Light grey quartzit . Dark grey quartz‘te. Biack quartzite. Red quarizite. Purplish quartzite. Pinkish quartzite. Pyroxenic quartzite. Spessartiferous quartzite. Quartzites containing manganese-ores Micaceous quartzite. Quartz-schist. Fine-grained mica-quartz-schist. Biotite-quartz-schist. Muscovite-schist. Manganiferous micaceous schists. Manganiferous gneiss. As we have only one deposit of any importance in Jhabua to deal with the list of rocks interbanded with the rocks of the gondite series there is naturally a smaller one than for the Central Provinces. It is as follows :— List of the rocks interbanded with the rocks of the gondite series in JThabua, Light grey, dark grey, black, red, and pinkish, quartzites, Pyroxenic quartzite. Spessartiferous quartzite, Manganiferous, micaceous, and pyroxenic, schists. Cuap. XVI. | GONDITE SERIES : PETROLOGY. 333 In Narukot at the one known occurrence of rocks of the gondite series the interbanded rocks are considerably different to those of the Central Provinces and Jhabua. The following is a list :— List of rocks inierbanded with the rocks of the gondite serics in Ndrukot. Quartz-rock. Red quartzite. Pyroxenie quartzite. Quartzite containing manganese-ores, Manganiferous micaceous schists. Whilst intimately associated with these are rocks composed of the fol- lowing minerals :—Quartz, garnet, pyroxene, epidote, hornblende, pla- gioclase, microcline, biotite, wollastonite, sphene, apatite, calcite, tourma- line, with in one case, chalcopyrite. The rocks composed of these minerals take the form of banded gneisses. Amongst the rocks given above as occurring interbanded with the rocks of the gondite series are in all three areas ‘ manganiferous micaceous schists’. These rocks are often of very complex composition owing to the great variety of minerals they contain. The following is a more de- tailed list of these rocks :— List of the manganiferous micaceous schists found associated with the rocks of the gondite series. In the Central Provinces :—Only known to occur to any extent at one locality Kacharwahi. These have not yet been examined. In Jhabua:—Found at Kajlidongri. Apart from the rocks containing the blue amphibole, winchite, and of which a list will be given below. the following rocks can be included in this group, tale sometimes taking the place of the mica :— Mica(yellow)-rock. Apatite-tale(?)-felspar-quartz-rock. Mica(crimson)-amphibole-apatite-tale-rock. Apatite-mica(orange)-blanfordite-quartzite. In Narukot:—Found at Jothvad. The manganiferous micaceous schists are such as, from their outward physical aspect, one would designate ‘ biotitic sandstones’ in the field. The following is a list :— Schistose banded rock containing the following minerals in one band :—apatite, microcline, plagioclase, quartz, manganese-ore (probably original), mica (showing pleochroism in pink, green, and orange), and a little of a blue pyroxene ; with a second band formed of quartz, apatite, manganese-ore, and pyroxene, pleochroie in pink and bluish green. Schistose rock composed of apatite, mica, microcline, quartz, manganese-ore, pyroxene (pink and green pleochroism), and an amphibole having the pleochroism of winchite. Schistose rock, included in granite, containing quartz, microcline, apatite, spessartite, mica (orange brown), hematite plates, and a black ore. 334 MANGANESE DEPOSITS OF INDIA : GEOLOGY. [Parr Il: At the Kajlidongri mine in Jhabua there is a series of rocks, associated with the manganese-ores, that is characterized by the presence of the lavender or blue amphibole to which the name winchite has been given (see page 149). These rocks have probably resulted from the metamorphism of a series of sediments characterized by the presence of large quantities of lime, magnesia, and manganese-oxides, in addit on to the ordinary sand and clay. The minerals contained in the rock thus formed :re the following :—Winchite, braunite, calcite, and quartz, with less frequently apatite, blanfordite, plagioclase, and crimson mica. Some 10 different combinations of these minerals have been found, but the most important are the following :— Last of winchite-bearing rocks. Winchite-schist, composed of about equal proportions of winchite, braunite, calcite, and quartz. Blanfordite-winchite-schist, composed of the foregoing minerals with blanfordite in addition. Winchite-quartzite. Blanfordite-winchite-quartzite. Banded rock of winchite, blanfordite, braunite, felspar, quartz, apatite, calcite, and crimson mica. As has been mentioned on a previous page, various interesting rocks are often found at the periphery of th masses of manganiferou’ rocks and are formed either by an interaction between the manganiferous sediments and the immediately under- or over-lying non-manganiferous sediments ; or, and more probably, by the direct metamorphism of these underlying or overlying sediments, which were not sufficiently manga- niferous to give rise to rocks of the gondite series or to ores, but which yet contained sufficient manganese to give rise on metamorphism to un- usual rocks. Of such rocks the following deserve notice :— Inst of manganiferous rocks forming the ‘ country’ of the gondite series. Manganmagnetite-gneiss of Kandri and Mansar. Spessartite-quartzite of Kandri and Mansar. Manganiferous mica-schist containing a crimson mica (biaxial), a brown mica (uniaxial), and quartz, at Sitapathur. Hematite (manganiferous)-quartz rock at Ramrama. Ottrelite-muscovite-schist at Sitasaongi and Balaghat. Piedmontite-phyllite at Kajlidongri Sandy-argillaceous rock containing winchite at Kajlidongri. In addition to the rocks characterized by a notable proportion of man- ganese, there is a great variety of rocks forming the actual ‘country ’ Cuap. XVI.] GONDITE SERIES ; PETROLOGY. 335 of the manganese-ore bodies and bands of manganese-silicate-rock. The following is a list of such rocks found in the Central Provinces :-— List of the non-manganiferous rocks forming the ‘country’ of the gondite series in the Central Provinces. Sericite-phyllite and schist. Mica(muscovite)-schist. Mica-quartz-schist. Magnetite-mica-quartz-schist. Biotite-schist. Felspathic mica-schist. Biotite-felspar-schist. Talcose schist. Schistose quartzite. Felspathic schist. Micaceous quartzite, often containing tourmaline. Quartz-rock. Quartzite. Jaspery quartzite. Hematite-quartzite. Martite-quartzite. Sapphirine(?)-enstatite-quartzite. Conglomeratic gneiss. Muscovite-gneiss. Biotite-gneiss. Hornbiendic quartz-pyroxene-gneiss. Calcivhyre. Crystalline limestone. Tourmaline-quartz-rock. This list should be compared with the list of minerals contained in these rocks given on page 325. In Jhabua the actual ‘country’ of the two deposits visited consists :— at Kajlidongri of sericitoid phyllites, usu-lly separated from th o-e-bedy by 2 small th ckness of arzillaceous-sandy rocks ; and at Rambhapur of siliceous crystalline limestone. In Narukot, at the single occurrence of the rocks of the gondite series, the actual ‘country’ of the manganiferous rocks consists of the banded gneisses, mentioned on page 323, with which they are so intimately associ- ated ; whilst the complex consisting of these interbanded manganiferous rocks and gneisses is surrounded by and invaded by porphyritic biotite- granite. Finally, it remains to give a list of the rocks found intrusive in the rocks of the gondite series. They are nearly all coarse-grained rocks, allied to pegmatite, and owe their peculiar composition as regards the minerals they contain to the fact that they have passed through rocks 336 MANGANESE DEPOSITS OF INDIA; GEOLOGY. [Part II: containing manganese before they reached their present position. The following is a list-of these intrusives :— List of rocks intrusive in the rocks of the gondite series. In the Central Provinces :— Pegmatite (Ramdongri). Spessartite-pegmatite (Bichua, Ghoti, and Satak). Pyroxene-(brown)-pegmatite (Sitapathtr). Quartz-felspar-rock with a brown mineral (Thirori). Felspar-rock with spessartite (Hatora). Microcline-rock with spessartite and quartz (Beldongri). Microcline-rock with brown pyroxene and bronze-coloured mica (Kosumbah). Albite-rock with braunite, blanfordite, juddite, and sometimes quartz (Kacharwahi). Blanfordite-granite (Ramdongri). In Jhabua :— Quartz-oligoclase-albite-carpholite(?)-rock (Kajlidongri). It is uncertain whether this rock is to be classified with the intrusives or with the mineral veins; it is here put in the former class on account of the presence of felspar, although felspar is also sometimes found in mineral veins. In Narukot :— Granite vein containing red garnet and a little pyroxene with pink and green pleochroism. Granite vein with blanfordite, greenovite, and garnet. Quartz-felspar(microcline and oligoclase)-rock. Porphyritic biotite-granite. In addition to the rocks enumerated above, which are found in the masses of the gondite series as veins or irregular patches, and are to be re- garded az the products of the intrusion and subsequent solidification of igneous or aqueo-igneous magmas, there is another set of vein-rocks that are probably to be regarded as true mineral veins deposited by mineralized waters percolating along cracks or fissures. The following is a list of such veins :— List of the mineral veins found traversing the recks of the gondite series. In the Central Provinces :— Quartz. Quartz with spessartite(?) (Bichua) Quartz with magnetite (Sitapathir). Tourmaline-quartz-rock(?) (Kodegaon). Pyrite in quartz(?) (Kodegaon). Opal (Kodegaon and Kandri). Chalcedony (Kandri). Hematite (Mansar F xtension). In Jhabua (at Kajlidongri) :— Hollandite and quartz. Hematite and quartz. Barytes and quartz, with an arsenate. Quartz with angular inclusions of psilomeian> In Narukot :-— None. Cuap. XVI.} GONDITE SPRIES: PETROLOGY. 337 It will be seen from the lists given on the preceding pages what a great variety of rocks there is, both constituting, and associated with, the man- ganese-silicate-rocks to which the name of the gondite series has been given. It will obviously be impessible for me to give here a full petro- logical account of this large number of rocks, interesting though they be, and IJ shall content myself with giving a short account of the most impor- tant varieties. Although the number of kinds of rock enumerated above is very large, yet only a few of them are of frequent occurrence. These more frequently occurring rocks have been indicated by being printed in italic type in the lists given on pages 329 to 332. Deseriptions of the more Important Roeks. The commonest and most characteristic member of the gondite series, and consequently the one to which the name Gondite. gondite has been given, is one made up of a mixture of manganese-garnet and quartz. Although this garnet has not the theoretical composition of spessartite, yet, if one can judge from two analyses (one of which was calculated from a rock analysis ; see page 351), it is sufficiently close to be included under this name. The typical variety of gondite is a fine-grained rock of uniform grain, the separate grains of which are just apparent to the unaided eye. In colour this rock varies from cream-coloured (this being a rare colour) through grey, yellow, buff, and cinnamon, to reddish and purplish. Under the microscope it is seen to consist of very numer- ous small idiomorphic garnets, in some parts isolated one from the other and in other parts aggregated into little groups, scattered through a matrix of mosaic quartz, the individual grains of which are usually of about the same average size as the garnets. In colour the garnets are of some shade of yellow, varying in thin sections from quite a strong sulphur-yellow to practically colourless. When the nicols are crossed, a very pretty effect is produced owing to the numerous uniformly-sized garnets appearing as dark spots scattered through a matrix of mosaic quartz polarizing in greys and whites. The appearance of this typicai gondite is well shown in the photo-micrograph (Plate 1], figs. 1 and 2). Frequently no other minerals can be detected in a thin section of gondite ; but just as often a careful examination of the section reveals the presence of a certain number of very small idiomorphic granules of apatite scattered through the quartz mosaic and sometimes also included in the spessartite. In one case, namely, that iliustrated in 11H 338 MaNGANESE DEPOSITS OF INDIA; GEOLOGY. [Parr II: the photo-micrograph (Plate 11, fig. 2). there is also a small amount of rutile present in the rock. The garnets are usually isotropic, but not infrequently, owing no doubt to strain effects, they exhibit anomalous double refraction. The relative proportions of the two constituents of gondite vary be- tween very wide limits, so that there is every gradation between quartz- rock free from spessartite and spessartite-rock free from quartz. The typical rock, however, may be regarded as that which contains about equal proportions of the two constituents. The microscope shows that those varieties that show purplish or reddish tints in the hand-speci- men do not as a rule owe their colour to the garnet being purple or red ; but to the fact that the separate grains of garnet each contain a small cloud of finely-divided red dust, probably oxide of iron, some- times uniformly distributed throughout the grain, but more often collected in the central parts of the grain so as to leave the periphery clear. The other variations of colour seem, however, to be due to vari- ations in the colour of the spessartite, which may range from almost colourless through pale yellow, bright yellow, and orange, to orange-red, or even deep blood-red. This variation in colour is no doubt due to vari- ations in the amounts of manganese and iron in the garnet. The fine- grained variety described above is perhaps the commonest variety of gondite and is to be regarded as the typical rock. From this degree of fine grain there is every gradation up to varieties of gondite of very coarse grain in which the garnets may be as much as 1 or even 2 inches in diameter. In these more coarsely crystalline varieties the garnets are often well developed so as to show their crystalline form. This is almost invariably seen to be the simple trapezohedron or icosatetrahe- dron, although other faces, for an account of which see the mineralogi- cal description of this mineral (page 172), are not infrequently found, Dana’s ‘System of Mineralogy’ does not indicate that particular varieties of garnet favour particular mineral habits. My experience, however, of the Indian garnets points to the fact that if a garnet exhibit predominant trapezohedral faces it is almost certain to give a strong re- action for manganese when fused with nitre and fusion mixture. In fact, in the Central Provinces one would almost invariably be correct if one designated all garnets exhibiting predominant trapezohedral faces as manganese-garnets, and all garnets in which other faces predominate as garnets practically free from manganese and far removed from spessartite in composition. There are exceptions to this rule, as is evident from the fact that a single example of an octahedral spessartite-garnet EXPLANATION OF PLATE ll. PHOTOMICROGRAPHS, Fic, 1.—Shows numerous small garnets (spessartite) in a matrix of fine-grained quartz (light). Fic, 2,—Shows spessartite-garnets tending to be idiomorphic, in a clear matrix of quartz. Occasional dark grains of rutile are also present, Fic, 3.—The dark mineral is spessartite and the light one quartz, Fic, 4,—Crossing the nicols brings out the strained structure of the quartz mesaic, which appears uniform in figure 3, GEOLOGICAL SURVEY OF INDIA. Memoirs, Vol. XXXVII. Pl.11 Fig. 1.— X 23. Fig. 2.—X 23. Very fine-grained gondite. Typical gondite. Jothvad, Narukot State, Bombay. Wagora, Chhindwara district, C.P. L. L. Fermor, Photomicrograph. Bemyrose, Collo., Derby. Fig. 3.—X 23. Fig. 4.— X 23. Strained gondite by ordinary light. Same as Fig. 3, but with nicols crossed. Ramdongri Nagpur district, C.P. Cuap. XVI.] GONDITE SERIES; PETROLOGY, 339 has been found at Chargdon. In these coarsely crystallized varieties the garnet varies from bright yellow to orange and orange-red. An examination of sections of gondite under the microscope some- times shows that apatite is present in considerable abundance. The rock can then be designated apatite- gondite. This variety is not, however, common, and no example has yet been found in which the apatite is conspicuous in the hand-specimen. Apatite-gondite. Less common than gondite and spessartite-rock are those varieties __ The rhodonite-bear- of the series characterized by the presence of rho- ing members of the : : ; Z : ae donite in considerable or predominant proportion. Of these the most abundant is a rock composed of a mixture of spessar- tite and rhodonite with or without quartz. The rocks containing rho- donite are never so fine-grained as the typical gondite. When composed entirely of rhodonite, or nearly so, they have a saccharoidal appearance resembling that of a crystalline limestone, although the colour is, of course, not white, but rose-pink when fresh. Under the microscope this thodonite-rock appears as an aggregate of roughly equi-dimensional cry- stals ; they are allotriomorphic in outline owing to the fact that they are pressed one against the other, except that there is a tendency for them to be somewhat elongated in the direction of the well-marked prismatic cleavage. A photo-micrograph of such a rock is given in Plate 12, fig. 3. More frequently, however, the rock does not consist entirely of rhodonite, but contains spessartite in either small or large proportion. When in small proportion the spessartite appears in the hand-specimen as rich orange-coloured rounded granules or crystals set in the pink rhodonitic matrix, the whole forming a most beautiful combination. In this rock the spessartite is often idiomorphically developed, sometimes as almost perfect trapezohedra, which are occasionally glass clear and then of the beautiful rich orange colour mentioned above. Under the microscope it is seen that the garnet is as a rule idiomorphic towards the rhodonite, which tends to enclose it. The proportion of spessartite may increase until it predominates over the rhodonite. Jn this case also the garnet tends to be idiomorphically developed with regard to the rhodonite, although in one or two cases I have noticed under the microscope more or less rounded crystals of rhodonite enclosed in the spessartite. In two cases I found this rhodonite-spessartite-rock to a beste the gon- contain a third constituent, of white colour, which was found on testing to be barytes. This con- stituent had every appearance of being an original constituent of the rock 11H 2 340 MANGANESE DEPOSITS OF INDIA : GEOLOGY. [Part i: as far as one could judge from its relations to the other components. If this be the case, we must suppose that the original sediments from which the gondite series was produced were in some cases highly barytiferous. This conclusion is supported by the high percentage of this element found in many of the ores ; although, if the supposed original barytes were not present, it might be supposed that the barium had been subsequently introduced. There is, however. nothing contrary to the experience of the present day in making this supposition that the original sediments con- tained barium; for we have an actual example in our own Indian seas, namely that described by E. J. Jones! of some nodules obtained by trawling off Colombo in water of 675 fathoms. These nodules were found on examination to consist almost entirely of barytes, one of them giving 82-5 per cent. BaSO, on analysis. One is very apt to overlook the presence of barytes in a rock when it is not presence in abundance. There are four minerals in the gondite series that require some care in dis- tinguishing. These are orthoclase, apatite, barytes, and arsenates, all colourless minerals with a low or comparatively low birefringence. The felspar can, however, be at once distinguished from the other three substances by noticing the index of refraction; this can be rendered more obvious by cutting off with the hand a portion of the light coming from the mirror of the microscope, or, if the instrument is provided with an iris diaphragm, by stopping down considerably. When this is done the orthoclase still shows an unpitted surface, while the other three minerals stand up in relief with a much pitted surface. For the method of distinguishing apatite, arsenates, and barytes, one from another see page 220. Another variety of the rhodonite-spessartite-rock is one containing, in addition to barytes, a green manganesian phosphate, for which see page 207. It is surprising that manganiferous phosphates have not been detected more often in the rocks of the gondite series than in this solitary case. Both the rhodonite-rock and the rhodonite-spessartite-rock often con- ligdonite spunea tain small quantities of quartz, which may increase in rock and rhodonite- quantity until the rock becomes a rhodonite-quartz- pondstes rock or a rhodonite-gondite, respectively. All the rhodonite-bearing rocks are distinguished from those free from rhodonite, such as gondite or spessartite-rock, by the fact that they almost invariably occur in layers or beds of a massive character, and do not often occur as 1 Rec, Geol. Surv. Ind., XX, p. 35, (1888), ~~ hos: = .* Re tila ae 7 Plat tht RPV eae Ai beet / . ie : 19 - " as = a ‘pie ADT ; TL On ; ; Be. - ’ a a - ae | i seers yd peytien) mm td eng f,') ib Vis tle! a \s . t EXPLANATION OF PLATE 12. PHOTOMICROGRAPHS,. Fic. 1.—The garnets are seen centrally blackened by manganese oxide, and are set in a matrix of mosaic quartz. Fic. 2.—Spessartite—light ; manganese-ore—dark, Fic. 4.—Pyrexene—light : manganese-ore—black. GEOLOGICAL SURVEY OF INDIA. Memoirs, Vol. XXXVII, Pl.12 Fig. 1.— x 33. ig 2.— X23. Gondite, with garnets altering. Spessartite-rock, partially converted into Ukua, Balaghat district C. P. manganese-ore. Mansar, Nagpur district, C. P. ].. L. Fermor, Photomicrograph Bemrose, Collo.. Derby. giles See Pe Fig. 4.—X 23. Rhodonite-rock. Pyroxene (Rhodonite?), altering to Ramdongri, Nagpur district, C. P. manganese-ore. Kodur, Vizagapatam district, Madras. Cuap. XVI.] GONDITE SERIES : PETROLOGY, 341 thin layers interbanded with equally thin layers of quartzite or quartz, as is so often the case with the rocks free from rhodonite. Not unfrequently members of the gondite series contain small ros- The amphibole. ettes of a fibrous mineral, which, when fresh, seems bearing members of to vary in colour from greenish grey to white, but Seis. which is more often altered to a brownish colour, usually some shade of chocolate. This alteration is seen under the microscope, to be due to the deposition along cleavage cracks of brown and black oxides, probably of manganese and iron. The mineral has not yet been critically examined, but is in all probability some variety of the amphibole group. It is found more often in the rocks containing rhodonite, with which it is sometimes seen under the microscope to be in parallel growth, than in those free from this mineral. At two localities, rhodochrosite has been definitely identified in Rhodochrosite in rocks belonging to this series ; whilst in many other the gondite series. cases small quantities of rhombohedral carbonates, formed in all probability by secondary changes from the manganese minerals with which they are associated, have been noticed in thin sec- tions. In the two cases of Gaimukh and Devi, however, the rhodo- chrosite may be an original mineral formed at the time of metamorphism of the original sediments. From the listsof rocks occurring in the gondite series as given on Felspar_ in the pages 329 and 330, it will seem as if these rocks ee frequently contain felspar. Such, however, is not the case, for each of the felspathic rocks mentioned has been found at only one, or at the most two, localities. In the Central Provinces at least, the felspar bearing members of this series are very rarely found. In the Central Provinces the felspar may be either orthoclase or microcline, whilst in Jhabua both orthoclase and plagioclase have been noticed. At Narukot only plagioclase has been found and this but rarely. It is this rarity of felspar in the gondite series that not only distinguishes it from the kodurite series, but is also an argument against the gondite series being of igneous origin. It will be seen from the list given on page 329 that piedmontite has Piedmoatite, aj. ot been found in the gondite series as represented 3 Anta eephcacmen in the typical area, namely the Central Provinces. * ms: This is because the piedmontite-bearing rocks, being associated with crystalline limestones, are found quite apart from the masses of the gondite series as defined on page 307. In Jhdbua and 342 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part II: Narukot, however, the calcareous manganiferous sediments were deposited in such intimate association with the arenaceous and argillaceous manganiferous sediments that it is impossible to separate them now that they have been folded together and metamorphosed. The consequence is that in both these areas piedmontite-bearing members of the gondite series are found, together with other rocks characterized by ahigh percentage of calcareous matter. Thus in Jhabua there are the rocks containing winchite and calcite, and in Narukot rocks containing calcite and wollastonite. In both the Central Provinces and Jhdbua arsenates have been nies ere found forming important constituents in masses Arsenates in the z z ‘ gondite series, of rock belonging to this series. In the one case in the Central Provinces, namely at Sitapdr in the Chhindwara district, the arsenate is associated with various manganese-ores, so that in this case it may not have been produced by the direct metamorphism of original sediments, but by the subsequent action of mineralized waters. This, however, is by no means certainly the case, and, from the nature of the minerals with which the arsenate is associated, it is quite possible that the arsenate and the minerals with which it occurs are the preducts cf the metamorphism of sediments con- taining arsenic, the metamorphic processes having possibly been aided by circulating waters bringing about a conceutration of the perhaps criginally more uniformly distributed arsenic. In the other case of a rock containing an arsenate, namely at Kajlidongri in Jhdbua, the rock must be regarded as the direct product cf metamorphism of the original sediments, for it is in all respects like other members of this series, except that it contains an arsenate as a very important constituent. The exact composition vf these arsenates has not yet been determined, but calcium and magnesium seem to be important constituents in Jhabua and calcium in the Central Provinces | Besides rhodcnite, other pyroxenes are sometimes, though very rarely, Pyroxenes in the found in the rocks of this series. These pyrexenes gondite series. have not yet been examined in detail, but as seen under the microsecpe they usually show not very strongly marked pleo- chroism in shades of yellow and brown, so that they may be allied to the manganese-pyroxene, schefferite. Such pyroxenes are especially abundant at Jothvdd in Narukot, but have also been found m the Central Provinces and Jhabua. i The Sitapdr mineral is partly phosphate. Cuap. XVI_] GONDITE SERIES: PETROLOGY. 343 The pyroxene showing the beautiful type of pleochroism in pink, blue, and hlac, has not been found in the typical rocks of this series as given in the list on pages 329 and 330; but it is a rather frequent constituent of the manganiferous micaceous schists associated with the gondite series in Narukot and Jhabua and with the winchite-bearing rocks in Jhabua. The manganiferous micaceous schists are not of sufficiently frequent occurrence to be further discussed here, but it will be as well to givea short account of some of the quartzites associated with the rocks of the gondite series. Blanfordite. A rock very frequently met with in the manganese-ore deposits of the Central Provinces is a black fine-grained quartzite, which is somewhat heavier than an ordinary quartzite and usually occurs interbanded with manganese-ore, for which it can, at first sight, often be mistaken. Under the microscope it is seen to owe its peculiar characters to the presence ofa large number of minute inclusions. The rock itself is very fine-grained, consisting of a quartz mosaic through which are scattered clouds of tiny black bodies. These are evidently mimute crystals of some definite mineral, for they are seen with a high power to be prisms or rods that showin cross sections as little rounded or polygonal hodies. Since the rock when powdered and fused with nitre and fusion mixture giv2s a fairly strong reaction for manganese, it is probable that these inclusions consist of some manganese mineral. Plate 13, fig. 1 shows a photo- micrograph of a specimen oi this rock from Balaghat. In this section the inclusions are especially abundant; but specimens can be found showing every gradation between this rock and quartzite practically free from such inclusions, there being a corresponding gradation in colour from black to white. Such rocks are to be eee as the pro- ducts of the metamorphism of arenaceous sediments containing varying amounts of admixed manganese oxide ; for, considering the intimate way in which the little idiomorphic prisms are scattered throughout all the grains of quartz, it is not probable that the manganese oxide has been introduced subsequent to the formation of the quartzite. Some manganiferous quartzites are, however, formed in this way. But in the rock so formed the manganese-ore is distributed in rounded patches. As an example attention may be drawn to the photo-miciograph of such a rock from Sivardjpur in the Panch Mahals, Bombay, shown in fig. 1 of Plate 10. Other localities for the black quartzites are Kodegaon, Black quartzite. 344 MANGANESE DEPOSITS OF INDIA : GEOLOGY. [Part II; Manegdon, Ramdongri, and Waregaon, all in the Nagpur district. Sometimes the manganese-ore in these quartzites occurs in small patches rather than in separate needles, as in fig. 2 of Plate 13. This section also shows what looks like a cavity lined with delicate black needles of a manganese mineral. Crossing the nicols shows, however, that this supposed cavity is really filled with mosaic quartz into which the needles project. Bright brick-red quartzites are also of fairly frequent occurrence, as, for example, at Baldghat, Ukua, and Kajlidongri. Like the black quartzites, these red varieties are very fine-grained, so that under the microscope they show a fine mosaic. The red colour is then seen to be due to the presence in the interior of each grain of a small cloud, usually collected towards the centre, cf a red dust, which is in all probability ferric oxide or finely divided hematite. Vhat it does occur inside the separate grains and not along their junctions is shown by the tact that if a piece of the rock be powdered and boiled with hydrochloric acid it does not lose its colour. If, however, the rock be finely powdered and fused with fusion mixture the iron can be extracted. Red quartzite. At both Kandri and Mansar there is a rock, which occurs in close Manganiferous association with the ore-body, that looks at first gneisses. sight like a rather fine-grained quartzite. It is pinkish to whitish in colour. A closer examination, however, shows that it is finely crystalline and contains scattered grains and streaks of a black mineral that is magnetic, but not sufficiently so for magnetite ; and since this mineral gives a reaction for manganese it is either manganmagnetite or, less probably, braunite. It will require a separation of a considerable quantity of the mineral before this point van be settled ; for it only occurs in tiny grains in the rock. Under the microscope ,the rock is seen to consist of a rather fine-grained aggre- gate of quartz and microcline, and sometimes plagioclase, with fairly abundant scattered granules of the black ore mentioned above. It sometimes, but not often, except near the ore-body, contains a little yellow garnet, presumably spessartite, in streaks; more often it giistens in the hand-specimen from the presence of fairly abundant scales of muscovite-mica, although this last constituent may be entirely absent. The rock may be called a manganiferous gneiss, or even manganmagnetite-gneiss, and has probably resulted from the metamorphism of sediments that were deposited immediately before » fe i rm ; ; ' Oe * - ». ' julie rm me ' mi pie ut M AP pF aia o) Li : “a se: bites hi) 2) AUT re ia eh Pale Oy «| uh vil) i p& me) uit ug } : 7 Nisaieh Hit as any i ya uy in he, i F i} igs hi WW ‘ey a + ay iit | Mt i 3) ey L ah Pe if ut ’ ; i! TH vil - - ¥ -_ / ’ . > > 6e> a a By bs ap se Pei em 7 7 a a : EXPLANATION OF PLATE 18. PHOTOMICROGRAPHS. Fic. 1—Shows innumerable black prisms of a biack manganese mineral, scat- tered throuzh a matrix of fine-grained mosaic quartz. Fie, 2.—The apparent cavity with inwardly projecting needles is really filled with quartz mosaic, as can be seen when the nicols are crossed. Fic. 3.—Quartz—white ; psilomelane—black. Fic. 4.—The quartz is clear white, whilst the felspar has its cleavage picked out by thin films of manganese oxide (black) deposited along the cleavage planes. IF INDIA. ) 4 Pl. XXXVIT, cm " Cuap. XVI.] GONDITE SERIES; PETROLOGY. *:~ 345 and after the layers of sediment that gave rise to the manganese-ore deposit. The sediment must have been unusually rich in alkalies, probably in the form of felspar derived from the disintegration of older granitic or gneissic rocks. The sediments must also have contained a small proportion of oxides of iron and manganese, the presence of which may be taken as indicating that the change from the conditions under which the main mass of the manganese oxides was deposited, to that under which practically non-manganiferous sediments were deposited, was not abrupt, but was marked by a period of deposition during which the mechanically deposited sediments were mixed with a little chemically deposited manganese oxides. Localities for the Rocks of the Gondite Series. I will new give a list showing the localities at which the various rocks of the gondite series have been found. This list will only refer to the Central Provinces because the lists already given for Jhdbua and Narukot each refer to one locality only. Localities will only be given ‘for those of the associated rocks that are not of common occurrence, as the others are found at many localities. List of localities for the members of the gondite series in the Central Provinces. Gondite :—At almost every occurrence of the rocks of this series; but Chikhla I, Wagora, Gumgéon, and Mansar, may be specified as specially good localities. Spessartite-rock :—At almost every place where gondite is found, but in much less abundance. The following localities are specially good :—Hatora, Chargéon, MAndri, Manegadon, and Parsioni. Rhodonite-gondite :—Sonegaon, Thirori, Devi, Guguldoho, Parsioni, R&mdongri, Satak L Rhodonite-spessartite-rock :—Gaimukh, Ghoti, Beldongri, Manegdéon, Panchéla, Waregaon. Apatite-gondite :—Guguldoho. Apatite-spessartite-rock :—Guguldoho, Kandri, Mandri. Amphibole-gondite :—Chaéndadoh, Chikmara, Hatora. Amphibole-spessartite-rock :—Hatora, Mandri, Parsioni, Amphibole-rhodonite-gondite :—Bichua. Amphibole-spessartite-rhodonite-rock :—Parsioni, Sitagondi. Amphibole-apatite-gondite :—Nandapuri. Magnetite-gondite :—Kachi Dhana, Kodegéon. Magnetite-spessartite-rock :—Kachi Dhana. ! Rhodochrosite-gondite :—Gaimukh. Rhodochrosite-spessartite-rhodonite-rock :—Gaimukh. Rhodochrosite-rhodonite-rock :—Devi, Gaimukh, Guguldoho{(?) Orthoclase-gondite :—Kachi Dhana Spessartite-orthoclase-rock :—Kandri, Microcline-gondite :—Kachi Dhana, Kandri. , ¥ Pyroxene-microcline-gondite :-—Sukli. 346 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part Tl: A patite-felspar-spessartite-rock with mica :—Sétak I. Orthoclase-am phibole-rhodonite-gondite with rhodochrosite (7?) :—Parsioni. Rhodonite-quartz-rock :—Guguldoho. Rhodonite-rock :—Asalpani, Wagora, Guguldoho, Manegaon, Panch4la, Risara, Sita- gondi. Rhodonite-rock with magnetite, spessartite, and manganese-mica :—Ramdongri. Barytes-spessartite-rhodonite-rock :—Ghoti. Barytes-spessartite-rhodonite-rock with a manganesian phosphate :—Chargaon. Of the associated rocks localities may be given for the following less common types :— Pyrozenie quartzites :—Beldongri, Junawani, Waregaon. Spessartiferous quartzites :—Chikhla I, Kandri, Kodegaon, Mansar Extension,Parsoda Manganiferous micaceous schists :—Kacharwahi. Hematite (manganiferous)-quartz-rock :—Ramrama. Manganiferous gneiss containing manganmagnetite :—Kandri, Mansar. Manganese-mica-quartz-schist :—Sitapathar. Ottrelite-mica-schist :—Balaghat, Sitas4ongi. Hematite-quartzite :—Thirori, Mansar Extension. Martite-quartzite :—Hatora. Magnetite-muscovite-quartz-schist :—Hatora. Hornblendic quartz-pyrozene-gneiss :—Sukli. Sapphirine (7)-enstatite-quartzite :—Chikhla I. Since it has been possible to assign the rocks and ores of the gondite Areas to prospect series to a definite system, namely the Dharwars, sailing gondite it should be possible to indicate in what areas future series. prospecting should be carried out for the purpose of finding further occurrences of these rocks. In the first place, since the occurrences of this series that have been found in the less meta- morphosed type of the Dharwars, known in the Central Provinces as the Chilpi Ghat Series, have all been found to occur near what seems to be the base of the series, the attention of prospectors might well be directed to the boundaries of this formation as mapped in the southern parts of the Balaghat district and the northern parts of the Bhandara district (see Plate 43). It does not, of course, follow that such work would be suc- cessful ; in the first place because the areas indicated may have been outside the limits within which manganiferous sediments were deposited ; and in the second place because any occurrences oi the rocks of this series might all be in the condition of unaltered manganese-silicate-rocks, such as gondite and rhodonite-rock, and consequently not worth working as a source of manganese under present conditions of metallurgical treat- ment. A reference to the map of the Nagpur-Balaghat area will also show that the extreme northern portions of the Nagpur district, namely those parts lying to the north of Chorbdoli and Junawani, and the ex- treme southern portions of the Seoni district, lying between the Pench river on the west and Katangi in the Baldghat district on the east, together GEOLOGICAL SURVEY OF INDIA Memoirs, Vol. XXXVII, Pl. 14 From a sepia drawing. PIEDMONTITE AND MANGANESE-ORE NODULES IN A PIEDMONTITE LIMESTONE. AROUND THE MANGANESE-ORE NODULE IS A THIN RIM OF PIEDMONTITE. 3 NATURAL SIZE. ’ 1 : ad Crap. XVI] GONDITE SERIES; PETROLOGY. 347 form an area lying between the manganese areas of the Chhindwdra district and western Balaghat. This area might well be examined with considerable prospects of success. If any deposits be located in this area it will in some cases probably be found cheaper to transport the ores north to the Chhindwara-Seoni portion of the Satpura Railway rather than to carry them south to the main line of the Bengal Nagpur Railway. In Jhabua prospecting for further occurrences of the gondite series should be directed to the extension towards the north and north-north- west of the Ardvalli rocks occurring in the Rambhapur area. Some unimportant deposits of manganese-ore have already been discovered on this line of strike. It will be seen from the geological map of India that the Aravallis of this area are probably continuous with the main outcrops of this system in Rajputana. Hence prospecting in the portions of Raj- putana lying to the north of Jhabua, as, for example, in the State of Banswara, might have some prospects of success. Indeed, I am told that manganese-ore of inferior quality has already been found in Banswara. A more extended examination of the metamorphic and crystalline area of Narukot and the adjoining portions of the Rewa Kantha area might reveal the presence of manganese-ores. Similarly all the areas of Dharwar, Aravalli, Champaner, or Chilpi, rocks in India might yield, on careful prospecting, further deposits of manganese-ore, as also any portions of the metamorphic and crystalline complex that are suspected to contain rocks of Dharwar age folded in with the older rocks. CHAPTER XVII. GEOLOGY —continued. The Gondite Series—concluded. Chemical composition—Alteration of the gondite series—Evidence of alteration— Time of alteration—Method of alteration—Depths to which the ores extend—Conclu- sions as to the origin of the gondite series and associated manganese-ores. Chemical Composition of the Gondite Series. As can be judged from the list of rocks given on page 329, the com- Composition of position of the rocks of the gondite series is very gondite. variable, and I propose to consider here only a few of the less complex members. As has been already mentioned, the type rock of this series may show every gradation in composition between quartz-rock free from spessartite and _ spessartite-rock free from quartz, z.e. between SiOg and 3(Mn,Fe,Mg,Ca)O.(Al,Fe,Mn).03.38i09, assuming this to be the composition of the manganese-garnet of the Central Provinces. In a case in which the garnet had the theoretical composition of spessartite the composition of spessartite-rock would be as follows :— MnO. -. .5 <_ -40"92 AlpOp. . . » 20258 Si0e . . . 36°50 Gondite composed of equal parts of quartz and spessartite, in one case by weight andin the other by volume, would have the composition shown below :— Equal parts by Equal parts by weight. volume. MnO ° ; ° . 21°46 26°25 AlgOg 5 : : 10°29 12°57 Si02 . 2 : . 68°25 61°18 100-00 100-00 An actual analysis was made of a piece of typical gondite (16-984) from Wagora in the Chhindwara district. This is the rock of which a photomicrograph is given on Plate 11, fig. 2. It is a cinnamon-pink or pinkish buff rock of fine grain. The specific gravity of the piece analysed was found to be 3°42. Under the microscope the rock is seen to Cuap. XVII.] GONDITE SERIES ; COMPOSITION. 349 be composed almost entirely of quartz and garnet with a small quantity of apatite and rutile. The analysis was made by Messrs. J. and H. S. Pattinson of Newcastle, the weight of the piece of rock ground up for this purpose being 42:23 grammes. The result of the analysis is shown below :— Analysis of typical gondite from Wagora, Chhindwdra district. G.= 3°42. No. 16:984. MnO i ; : A : 5 : 18393 37/ Fe203 : : : : : : ‘ 7°47 FeO - 5 3 c 3 s : 0°13 Alz2O03 : ; - : : 2 : 12°36 CaO : F Z ; ‘ 4 ; 2-60 MgO , - : : 5 : 1-90 K 90 . - , : 5 4 : 0°03 NaQO ‘ ‘ : : t : é 0-19 Si09(com bined) : 2 : ; 20-60 Si09(free) ; . 5 : A A 39°85 P205 : 3 ; ‘ : ; : 0-68 CuO ; 5 : 5 A 5 : 0°02 TiOg ‘ . : 3 - , : 0:46 cl. 5 . x : : s E Trace. Combined water 3 - 5 ‘ 0-20 Moisture at 100°C. . e ; : Z 0-10 99°96 Manganese : ‘ ; : : 10°36 Tron é 5 - 5 s “ r 5°33 Silica (total) . : ; P 3 ; 60°45 Phosphorus - : : : . : 0°30 The process adopted in calculating this analysis into terms of the mineral composition of the rock is to first take out the titania (TiO9) as rutile, and next to take the lime (CaO) necessary for the formation of apatite with the phosphoric oxide (P)0;), the required amount of chlor- ine or fluorine being assumed to be present. The free silica is all assumed. to be in the form of quartz, as there was no evidence of the presence of any other form of free silica such as chalcedony. There are then two methods that may be adopted in dealing with the remainder of the constituents. In either case the cupric oxide (CuO), combined water, and moisture, are not considered, but are regarded as impurities. The alternatives are either to regard the potash and soda as impurities, or to suppose that they are present as felspar. Taking the first alter- native (I) and thus regarding the combined silica as all present in the garnet, this silica is used as the basis of calculation. More than suffi- cient alumina (Al03) is present for the formation of spessartite, so that 350 MANGANESE DEPOSITS OF INDIA: GEOLOGY, [Parr IT; all the other oxides must be present in the protoxide portion of the garnet, for which there is not enough manganese protoxide (MnO). For this reason it is necessary to regard the larger portion of the iron as forming a part of the protoxide portion of the garnet, although the iron is mostly returned as being in the form of ferric oxide (Fe203). The other alter- native (II) is to regard the alkalies as present in the form of orthoclase and albite, although neither felspar is visible under the microscope. For it does not follow that there is not present in the rock the very small proportion of felspar to which the alkalies present correspond ; for such a small quantity of felspar might easily be overlooked, especially if not twinned. After setting aside the amounts of alumina and silica required for the felspar, the remaining constituents can be combined as garnet in the same way asin the former case; but the analysis does not then work out so well, because there is then a larger amount of ferric oxide and alumina left over unaccounted for. It would of course be possible to calculate a portion of this residue as a further amount of garnet by taking a little of the silica that has been entered up in the analysis as free silica. The following shows the mineralogical composition of the rock according to these two methods of calculation :— I II Rutile. : 5 F - 0°46 Rutile 3 : f = 0-46 Apatite . F ; us . 1°58 Apatite 2 2 . - 1°58 Spessartite :— Spessartite :— MnO 5 LBs MnO S aS-37 FeO : 5°43 FeO 2 x tod CaO a 1-70 CaO ‘ - Jei0 MgO : 1-90 MgO. =~ 790 AlOz, . 11°89 AleO3 . . 10°91 Si02 E2060 Si0g . - 19°38 54°89 54°89 51°23 bl-23 Fe203 1-58 Fe.03 . : 3°20 AlgO3 0°47 AlgO03 i 2 i Nea ty Surplus oxygen 0°59 Surplus oxygen 0°43 20 . F 0°03 Orthoclase “ = 0°17 Na :O 0-19 Albite : 1-61 Quartz 39°85 Quartz 39°85 CuO ; 0-02 CuO : = . 0°02 Combined water 0-20 Combined water - Oe Moisture at 100°C. 0-10 Moisture at 100°C. . 0-10 99-96 99-96 Taking the mineralogical composition of the rock as expressed in colunin I, and knowing the specific gravities of quartz and of the rock to Cuap. XVII.] GONDITE SERIES ; COMPOSITION, 351 be, respectively, 2°65 and 3:42, it is easy to calculate the specific gravity of the remainder, which consists practically entirely of spessartite. The result thus obtained will therefore be very close to the true value for the specific gravity of spessartite—if anything just a trifle too low, because the other constituents mixed up with the garnet are all of lower specific gravity, except the rutile, which has practically the same value for this constant as spessartite. The value thus obtained is 4-24, which may be taken as a very good value for spessartite. Neglecting all the constituents of the rock except the quartz and spes- sartite, and calculating to 100, the composition by weight and by volume works out as follows :— Composition of gondite Composition of gondite by weight. by volume. Spessartite . . 57°94 Spessartite . ; - 46°30 Quartz : - 42°06 Quartz : : y ‘53:70 so that the piece of gondite chosen as being typical consists of about equal proportions of quartz and garnet by volume. From this analysis we can also calculate the composition of the spessartite. This works out to the figures shown in column I below, whilst column II gives the result of an analysis made by Mr. T. R. Blyth, of the Geological Survey of India, of a specimen of manganese- garnet from Chargaon in the Nagpur district :— I II Spessartite from Spessartite from Wagora. Chargaon. MnO : ° ° . - . 24°48 30°29 FeO c : ° : 3 . 9-94 ( =44-34 = =40°82 CaO R - on ase ‘ : 3-1 MnO 4:97 MnO MgO eee 8-48 2-40 Alp03 : - - - s - 21°26 8:05 Fe203 C ° : : ° . ss or-26 =-a8} =19-°56 Mn203 Ct. : : = . : Alg03 9-50 AlgO3 SiO: 3 2 2 c : = ol-ao 34°71 Surplus MgO . - - - : 5c 3°00 100-00 101-30 Oxygen assumed 3 ; : 1, NL 0-96 100-00 100-34 It will be seen that the analysis of the Chargion garnet does not agree very closely with the theoretical composition of garnets, namely that expressed by the general formula 3R”O.R’’’,03.38i0g, there being 352 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Part jue a surplus of 3 per cent. of magnesia. The state of oxidation of the manganese and iron was not determined, because the quantity of fairly pure garnet separated for analysis was not sufficient for this purpose. Owing, however, to the small quantity of the sesquioxides, AlhO, and Fe,03, it is necessary to assume that a portion of the manganese is present in the form of manganese sesquioxide, MnoQsg, in order to form the group R20 in the garnet formula. This is, of course, somewhat unusual ; for manganese is not usually supposed to be present in the sesquioxide portion of garnets, but only in the protoxide portion. The variation in the amount of manganese present in these two garnets is considerable, but the general composition of them is sufficiently near to the standard composition to warrant the use of the term spes- sartite to designate them. The variation in the amount of manganese present could well account for the variation in the colour of the manganese-garnets of the Central Provinces. In this case it is somewhat difficult to compare the colours of the two garnets , because the Wagora garnet was distributed as small granules in a piece of gondite where its colour was to some extent masked and diluted by the quartz with which it was associated. Nevertheless, I should say that the Wagora garnet was, as would be expected from the smaller percentage of manganese it contains, distinctly paler in colour than the Chargdon garnet. In the latter case the specimen analysed was obtained by breaking up and care- fully picking two or three trapezohedral crystals, which were of a deep orange colour. The only other member of the gondite series whose composition x we need consider is that composed of rhodonite cps ene and quartz. Here again it is obvious that the rock may show every variation in composition between that of quartz-rock- free from rhodonite and that of rhodonite-rock free from quartz. The Indian rhodonites have not yet been examined analytically, so that it is not known if they conform to the composition of the typical mineral, 7.e. have the composition expressed by the formula MnSiOs, or if a portion of the manganese is replaced by some other element such as calcium. Assuming the Central Provinces rhodonite to have the theoretical compostition, then the composition of rhodonite-rock would be as follows :— MnO. 2), 2 ee ee Si0, i en os ej abe corresponding to a manganese contents of 41°86. Assuming the specific gravity of rhodonite to be 3°63, the chemical composition of rhodonite- Cuap, XVII.] GONDITE SERIES ; ALTERATION, 353 quartz-rock made up of equal parts of the two minerals by weight and volume, respectively, is shown below :— Equal parts by Equal parts by weight, volume, MnO. - pee Ou 31°25 Sid. . - - 72°98 68°75 Mn 5 ; - 20°93 24°21 In the same way the composition of given mixtures of quartz, rhodo- nite and spessartite, forming different varieties of rhodonite gondite, could be calculated. Alteration of the Gondite Series. Evidence pointing to the Formation of Manganese-ore by the Alteration of Spessartite and Rhodonite. I have already mentioned that a portion of the ores of the deposits associated with the rocks of the gondite series has been formed by the alteration of various rocks belonging to this series. I propose to give here the evidence on which this statement is based and to consider the way in which the alteration took place. In many places the quarrying operations have laid bare masses of gondite or spessartite-rock traversed by a black network of manganese oxide in all stages of con- solidation into hard manganese-ore. An especially good locality for this is Mansar, where, in December 1906, there were some good exposures at the western end of the deposit. The solid manganese-ore was separated from the yellow spessartite-rock by very irregular boundaries, which had no relation to the bedding planes of the rock. From these masses of manganese-ore, veinlets of ore were seen to branch out into the yellow rock and there form anastomosing networks, which in some places ran together to form small masses of ore similar to the larger masses from which the veinlets came. In other places the rock was almost entirely black, with small irregular yellow patches, which looked as if they were the residuum of a rock that was once all yellow. The deduction that the original rock was all yellow and composed of spessartite, with a certain amount of quartz in places, is confirmed by a study of these rocks under the The Mansar deposit. We 354 MANGANESE DEPOSITS OF INDIA : GEOLOGY. [Part II: microscope. On Plate 12, figure 2, is shown a photo-micrograph of a section of this partially altered spessartite-rock. A reference to this will show that there are irregular patches and veinlets of pee See of manganese-ore spreading thoroughout the spessar- manganese-ore and tite. Now there are three possible ways of Ea explaining this association of manganese-ore and spessartite with each other. They are as follows :— 1. The manganese-ore and the spessartite were formed at the same time, during the metamorphism of the original sediments. 2. The manganese-ore, under the influence of metamorphic agencies accompanied by an influx of silica in solution, has been partially converted into spessartite. 3. The spessartite has been partially altered into manganese- ore, the original rock having been composed entirely of spessartite. The relations of the two minerals one to another in the section, show that the first explanation cannot be correct. For if it were, one of the minerals should be idiomorphic with regard to the other ; or if the two minerals crystallized at the same time they should be intergrown in a more or less poikilitic manner, or mixed together as a granular aggregate. If the second explanation were true we should expect to see veins of spessartite traversing the manganese-ore rather than the reverse rela- tion shown by the figure. By the process of elimination we arrive at the conclusion that the Spessartite changes third explanation is probably the correct one. to manganese-ore. According to this, we should expect to see irregular patches of manganese-ore encroaching on the spessartite, and small veinlets traversing it. The photomicrograph shows that such is the case. The examination of a large number of field exposures and thin sections of rocks has convinced me this is not an isolated example, but that the direction of change is really from garnet to ore and not the reverse. This explains the numerous cases of manganese-ores with irregular patches of spessartiferous rock, often disposed more or less centrally in a block of ore bounded by joint planes. If the change were the reverse, one would expect the manganese-ore patches to be central, and the spessartite being formed by alteration to be peripheral. Cuap, XVII. ] GONDITE SERIES: ALTERATION. 355 The rhodonite-bearing rocks indicate the same direction of change. Alteration of When the rhodonite is coarsely crystalline, a rhodonite. microscope section often shows lines of alteration extending along the cleavage planes of the mineral, and thence spreading out to form networks and patches of ore. The appearance seen is like that shown in figure 4, Plate 12, although this is actually a photo of a pyroxene from the Vizagapatam district. This can be taken as conclusive evidence that, in the case of the rhodonite also, the direction of change is from silicate to ore, and not the reverse. Time of Alteration of the Manganese-silicate-rocks into Manganese- ores. As there is, hence, little doubt about the direction of change in these rocks, we can now inquire when the alteration took place. On page 321 I have already mentioned a case of the inclusion of manga- nese-ore in Archean granite, and the possibility that this indicates that the alteration of silicate to ore took place, at least in part, in Archean times. It is of course not possible to say if this also apply to the Central Provinces. It is interesting to note, however, that many of the deposits, such as Mansar, showing spessartite-bearing rocks in every Hill deposits are Stage of alteration to manganese-ore, crop out in dry. the form of small hills, which on being quarried are found to be remarkably dry and free from water. From this consider- ation alone I should say that the alteration is not now taking place in such deposits, except, perhaps, for a certain amount of surface oxidation. In the case of the deposits that are buried in the alluvium it is difficult to say if the change is still going on or not. Probably it is to a small Highest points of a extent, considering that there is usually a free gondite band consist influx of water int, fhe deposit. It is a notice- Bane saeke-Ore- able point, howeve.,s chat if one traces a band of the gondite series along its strike it is usually found to reach its highest point in places where there are bodies of workable ore, the rock in between consisting of one of the varieties of manganese-silicate-rock, witn much less or practically no associated manganese-ore. This 1s weli seen in cases where the manganiferous band crops out continuously above the surface ; e.g. at Mansar, where the most valuable portion of the deposit also fortas the highest portions of the hill-range in which the band is situated ; or at Kandri where the rock forming the saddle between North and South hills is composed of gondite, whilst the hills them- selves contain fine bodies of workable ore; or at Ramdongri, II 12 356 MANGANESE DEPOSITS OF INDIA; GEOLOGY. [Part II: where the best ores seen 7m situ form the highest portions of hills 4 and 5 (see Plate 24). Now the deposits, the summits of which just reach the surface of the ground, such as several of those on the Dumri- Khandala line of strike, are shown by the quarrying operations to be small hills or hillocks, separated one from another by considerable thick- nesses of alluvium, which covers up the lower ground between the hiilocks. The character of the ore-bands on this lower ground has not been ascertained; but, on the analogy of the manganiferous bands exposed at the surface, it is not probable that it consists continuously of manganese-ore, but rather that it consists, at least in part, of quite fresh or only partially altered manganese-silicate-rock. Hence it seems probable that, with these deposits also, if the covering of alluvium could be removed, we should find the bodies of manganese-ore forming the hills and hillocks, with manganese-silicate-rocks on the necks between. So that we see that, judging from those deposits that form small hills projecting above tne present plains, and probably from those now buried in alluvium, it is necessary to suppose that the bodies of manganese-ore resist the agencies of denudation better than the majority of the mangan- ese-silicate-rocks ; the exceptions being the massive rhodonite-rocks, which seem to form just as marked hills as the masses of manganese- ore, as, for example, in the highest portions of Manegaon Hill. Hence these bodies of manganese-ore must have been formed before the present topography was carved out by the weathering agencies. I have already mentioned the probability that a portion of the man- ganese-ores was formed by the direct compression of original manganese- oxide sediments during the Dharwar folding. Hence it might be these bodies of ore that gave rise to the hills when the rocks were carved out by the weather; whilst the ores formed by alteration of the man- ganese-silicate-rocks might haye been formed subsequent to the pre- sent topography. That the g teer is probably not the case is shown by the Mansar deposit, where it is evident that the ores have been formed by the alteration of manganese-silicate-rocks, even though they give rise to the highest portion of the hill-range in which the deposit is situ- ted. Hence we arrived at the conclusion that even the ores formed Manganese-ore de. Py the alteration of the manganese-silicate-rocks posits formed before must have been formed largely, if not entirely, present topography. before the topography of the country assumed its present shape. This deduction agrees with the dry condition of the hill deposits, mentioned on page 355. This does not tell us, however, whetber the ores were all fomned in Archean times on the analogy of bey) Cuap, XVII.] GONDITE SERIES : ALTERATION, 357 those of Jothvad, or whether the alteration has continued in part almost down to recent times. But on page 363 the absence of any except rare open spaces in the Probably formed in OFe-bodies is taken as indicating that the larger part Archean times. of this alteration took place in Archean times towards the end of the Dharwar tectonic disturbances. The Way in which the Manganese-silieate-rocks alter to Manganese- ores. We can now consider the way in which the alteration of manganese silicate-rock to manganese-ore took place. From the consideration of the rock undergoing alteration and the products of the alteration, it is evident that, in the case of spessartite, the result of the alteration is a removal of :— (1) most of the alumina ; (2) a very large proportion of the silica, sufficient of this being left behind for the formation of braunite ; (3) a certain proportion of the small quantity of lime and magnesia present. As the manganese was to a large extent present in the garnet in b The formation of the form of protoxide, there must have also been raunite and _psilo- 4 cS hi : 5 aie melane. an introduction of oxygen in solution, this raising the state of oxidation of the manganese. We see from this that the reactions taking place must have been somewhat analogous to those hypothecated to explain the alteration of the kodurite rocks. The formation of braunite might be expressed thus :— 11 (3Mn0. Alz03.3Si02) + 170 =3(3Mnz203.MnSiOg) + 4Mn2MnO; + 11A 1203 + 30Si02. Spessartite, Oxygen, Braunite, Psilomelane, So that the equation should not be too complicated I have put the formule of spessartite, braunite, and psilomelane, in their simplest forms. The small amounts of lime and magnesia that enter into the RO group of the spessartite, partly found their way into the psilomelane, replacing a portion of the manganous manganese, and perhaps to a very small extent into the braunite. Any portion of these constituents left over must have been removed in solution. Any ferrous iron in the RO group of the spessartite was no doubt oxidized to the ferric condition. Any manganic manganese in the ROs group of the spessartite went to form a portion of the braunite or psilomelane, whilst any ferric iron in this group probably went mostly into the braunite and to a smaller 358 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Parr if: extent into the psilomelane. The psilomelane is represented in the equa- tion aS a manganate of manganese of the formula Mn jMnO;. The theoretically pure mineral of this composition has not yet been cer- tainly identified : for a portion of the basic manganese is always replaced by calcium, magnesium, iron, derived from the spessartite as explained above ; by hydrogen, derived no doubt from the waters that brought about the alteration ot these rocks; and by barium, which, in the ab- sence of any evidence of its existence in the original spessartite or gondite, must be supposed to have also been brought in by the attacking waters, though possibly only irom another part of the deposit ; for as mentioned on page 339, some of the rocks of the gondite series contain barytes, The amounts of alkalies in the Central Provinces psilomelanes are too small to be worth consideration. From the equation it will be seen that the chief constituents to be removed are the alumina and nearly all the silica. One result of the removal of the alumina and silica would be that The ores are not the residual mixture of braunite and psilomelane, porous. formed in accordance with the equation on page 357, would be very porous. For if the following specific gravities be assumed : spessartite, 4:2; braunite, 4°8; and psilomelane, 4:3; then according to the equation, 100 cc. of spessartite would give rise to 29-2 cc. of brau- nite and 17°6 cc. of psilomelane, so that the total volume of the braunite and psilomelane would be 46:8 cc., or not quite half the volume of the original spessartite. The fact that the masses of ore are no longer porous, except for occasional cavities found in almost all the deposits, can be explained in two ways. In the first place, if the alteration of the ores took place in Archean times, there may have been subsequent tectonic disturbances sufficiently intense to compact the porous and cavernous masses of ore. I do not, however, think that this explanation would apply to the majority of cases, for the simple reason that I do not think the ores ever were in this porous condition. The The ores formed by ; : ; : combined replacement €Xamination of numerous microscope sections of and decomposition of gondite in process of alteration has convinced Pepa ei me that the alteration is of the nature of a replacement, in which the incoming solutions add a portion of manganese oxide to that liberated in accordance with the equation given on page 357. The best rock in which to study this replacement is gondite, or spessartite-quartz-rock ; because, in rocks made up entirely of spessartite, it is difficult to distinguish alteration from replacement. In the sections of gondite, it is often Cuap. XVII.] GONDITE SERIES ; ALTERATION. 359 seen that the quartz is being bodily replaced by manganese-ore, with- out the spessartite being appreciably affected. In other sections, in which the change has gone further, it is seen that the spessartite has also suffered replacement, with the production of solid masses of manganese- ore containing residual patches of spessartite. When it comes to the replacement ot the garnet the solution seems to have taken advantage of any cracks in the mineral to percolate into its inside and there deposit its manganese oxide, And from these cracks the replacement seems to have spread out in all directions, so that the final result is a mass of manganese-ore with very few or no residual patches of spessartite. * When there were no cracks the garnet has been attacked from its ex- terior, ragged projection of manganese-ore growing intoit. It is evident that this replacement-conversion of the garnet into manganese-ore must be a combined decomposition and replacement in which the attacking solutions break up the garnet somewhat on the lines represent- ed in the equation on page 357, and at the same time deposit manganese oxide in the interspaces that would be left if the reaction only proceed- ed according to that equation ; the manganese oxide deposited being thus added to that already in the garnet. This formation of the ores by a combined replacement and breaking up of the garnet means of course that the incoming waters must contain manganese salts in solution. Meeeiet resample Such manganese was derived, in all probability, showing solution of from other parts of the deposit where solution was ce going on instead of deposition. Now in the masses of kodurite many examples are seen of rocks from which the manganese has passed into solution ; but in the case of the manganese- ore deposits of the gondite series it is very difficult to point to any particular example or case of gondite or other allied rock from which the manganese has been removed. In figure 1, Plate i2, is shown a photo-micrograph of gondite in which the garnets are each of them suffering alteration with the deposition or liberation of manganese oxide in the interior of each crystal, without the periphery of the crystal being affected. This is possibly a case in which replacement is not going on, for the quartz is practically unaffected. Hence it is possible that it is an example of gondite being attacked under conditions that will permit of the passage of the manganese into solution. The next point to be considered is the character of the solutions Carbon dioxide as that were able to dissolve the manganese of the the reagent producing garnet or rhodonite in one part of a mass of rock ekerargn: and deposit it in another part of the same mass 360 MANGANESE DEPOSITS OF INDIA: GEOLOGY, [Part Il: with the concomitant decomposition of the garnet and leaching out of the constituents not necessary for the formation of the manganese- ores. Two of the commonest reagents concerned in the formation of mineral deposits are carbon dioxide and sulphuric acid. Considermg first the carbon dioxide, we can suppose that in some parts of the mass of gondite or other rock it attacked the rock with the passage of the manganese into solution as bicarbonate, in a way similar to that supposed in the case of the decomposition of spandite (See page 266). This would mean the residual accumulation of the alumina as kaolin mixed with the quartz of the gondite. Kaolinic material is occasionally found in association with the deposits of the gondite series, but only rarely ; so that in this respect the theory is not supported by evidence. As in the case of the alteration of the kodurite masses, the solutions must have eventually become saturated with manganese bicarbonate. After this, on coming in contact with the other masses of gondite, the tendency would be for the solutions no longer to dissclve manganese but to deposit it instead, a replacement of the gondite being effected at the same time, with the passage into solution of its silica and alumina. The same difficulty arises as in the case of the kodurite series as to the removal of the alumina, which, according to the experience of the laboratory, would be precipitated in the presence of carbon dioxide or carbonates. As in the case of the kodurite series, we can suppose that under the conditions of the reaction in Nature alumina is slightly soluble in water containing carbon dioxide. Now let us consider the possibility of sulphuric acid as the reagent Sulphuric acid as hat brought about the various changes that the reagent producing have affected the gondite series. In the first gai place it would be able to remove the alumina in solution in the form of sulphate. Moreover, according to the experiments of Karsten [Comey’s ‘ Dictionary of Solubilities’, page 360, (1896) ], silica in the form of silicic acid is soluble in sulphuric acid. Further, it is well known that all the oxides of manganese are soluble in concentrated sulphuric acid with the formation of manganous sulphate, often with liberation of oxygen. Butin Nature the acid, if present, would probably be dilute, even very dilute. Now the action of dilute sulphuric acid on the various oxides differs. MnQOs is not attacked at all, whilst Mn,03 and MngOy, give up a portion of their manganese, so that in each case MnOg is left. Hence, during the decomposition of the garnet, if it took place in the presence of solutions of sulphuric acid, any manganous oxide in the RO group would go into solution as MnSQ,, whilst any Cuap. XVII] GONDITE SERIES: ALTERATION. 361 Mn, 03 in the R203 group would be attacked, with the solution of the MnO portion and the leaving behind of the MnOz portion. Hence the result of the attack of solutions carrying sulphuric acid would be to remove both the alumina and the silica, and also to remove all the manganese present in the protoxide condition, and a portion of that present in the sesquioxide condition, the residue being the peroxide of manganese. Since the pro- toxide portion of the spessartite is far more important in quantity than the sesquioxide portion, the result of the attack of sulphuric acid solu- tions would be the removal of the greater portion of the manganese as manganous sulphate. Such attack, with the solution of manganese as sulphate, might go on until the solution was saturated with the various substances dissolved. We must then suppose that on coming in contact with a fresh portion of the gondite or spessartite-rock the tendency would be for a further porticn of the alumina and silica of the garnet, and of the silica of the quartz, to pass into the solution, with the deposition of a corresponding quantity of manganese oxide, which would be added to the manganese oxide, and other constituents necessary for the formation of manganese-ore, already in the spessartite. In the presence of oxygen in the attacking: solutions the formation of the manganese-ores may have taken place according to the equation shown on page 270, in which the Al,03 and SiO, passed into solution, with the precipitation of an equivalent amount of MnO, which was converted into a higher state of oxidation by the oxygen. It might be objected that if the attacking solutions contained both manganous sulphate and oxygen, the manganese should have been deposited as oxide without the intervention of the garnet. It must be noticed, however, that the MnSO, was supposed to have passed into solution by the reverse reaction, which would not be undone except with a change in the conditions; and that the experiments of F. P. Dunnington’ show that the manganese of manganous sulphate is not precipitated by the action of oxygen alone, but that the presence of some such substance as CaCO; (which in Nature would probably be found in the form of limestone) is necessary, the deposition then taking place according to the following equation :— MnSOg + CaCO3 + O = CaSOs + Mn02+COdz. n this particular case the constituent to take the place of the manganese in the sulphate would be aluminium instead of calcium. 1 Amer, Jour. Sci., 3rd Series, XXXVI, p. 177, (1888). 362 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Parr II: For the alteration of rhodonite similar equations to those for Alteration of rhcdo- SpesSartite can be formed. Thus the formation nite. of braunite might be represented as follows :— 7MnSiO3 + 30 = 3Mn20z. MnSiOg3 + 6Si02; Rhodonite. Braunite, whilst a somewhat more complicated equation on the lines of that on page 357 could easily be constructed to show the formation of psilomelane. It is to be noticed that these equations are independent of whether the attacking solutions contain CO, or H2SO,. Thus it will be seen that either carbon dioxide or sulphuric acid would be able to produce the changes noticed, the sulphuric acid accounting for them more completely on account of its ability to remove alumina in solution ; but if the supposition that carbon dioxide can also dissolve alumina under the conditions prevailing in Nature be true, then either reagent would do equally well. Now there is no direct evidence pointing to one as the reagent more than the other. Still, we might look Carbon dioxide the for indirect evidence and see if possible sources more probable reagent. for either of these reagents exist in the other rocks forming the Archean complex in this area. Nowa most notice- able feature of this Archean complex is the rarity of any sulphides, either as constituents of the rocks or as vein-forming minerals,’ or of any rocks or minerals that may be supposed to have once contained sulphur. All that I have seen are barytes in the gondite series, copper sulphide minerals in basic dyke-rocks and in quartz, and pyrite ina chert vein, all of them being very rare. On the other hand crystalline limestones are found in great abundance and variety in this region. Hence we can suppose that it was carbon dioxide rather than sulphuric acid that brought about the alteration of the gondite series. It is to be noticed that the pyroxenic gneisses of this area are supposed to have been originally impure calcareous sediments ; and that in their formation carbon dioxide was liberated ; some of this converted portions of the gneisses into calciphyres and crystalline limestones (see page 299): the remainder may have brought about the alteration of the rocks of the gondite series. 1 Vein-forming sulphur-containing minerals, even if present in abundance, would probably have been deposited after the formation of the manganese-ores, if the fore- going theory as to the time of alteration of the gondite series be correct. Cuap. XVII] GONDITE SERIES: ALTERATION. 363 Whether the reagent was carbon dioxide or sulphuric acid, there Rarity of open should be loose or cavernous masses of rock left ae in the altered vherever the solvents attacked and dissolved with- out depositing something in return. But, except for occasional spaces in the ore-body, such cavities are not found. This may possibly mean that the changes took place prior to the last set of compressing earth movements that affected the rocks of this area. If the earth movements that faulted and folded the Gondwana rocks can be supposed to have affected the ancient crystalline rocks to any serious extent, then they would possibly have been sufficient to close up the spaces hypothecated above. But the probability is that these movements would have been insufficient to close up spaces formed in narrow bands of rock that formed but a very small proportion of the already highly com- pressed and therefore highly resistant rocks of the Archean complex. Hence if these spaces really did exist and have since been closed up by compression, it is necessary to go back to the series of earth movements that affected all the Archean rocks at the end of the Dharwar period. At first sight this may seem to be inconsistent, because these move- ments have been already called in to explain the metamorphism of the manganese-oxide sediments with the formation of the gondite series. It does not follow, however, that the folding that took place at the end of the Dharwar period of sedimentation, consisted of one prolonged compressive movement. We can imagine a period of compression during which the more deeply lying portions of the manganiferous ' sediments were metamorphosed to the condition of the gondite series, followed by a period in which the pressure was released. On referring to page 291 it will be seen that the formation of the manganese silicates, Further reasons for spessartite and rhodonite, involved the liberation Seiad (th age of oxygen. It is not necessary that this oxygen Archean times. should have been removed very far from the compressed rocks, and this may be the very oxygen that, aided by carbon dioxide or sulphuric acid, produced the conversion of a portion of the manganese silicates back into manganese-oxide ores, according to the equations given on pages 357 and 362. This period of diminished pressure may have been of some duration, giving time for the conver- sion of a considerable proportion of the manganese-silicate-rocks into manganese-ore. Any open spaces thus formed would be closed up by another period of compression, sufficient to close the spaces and yet not sufficient to again convert manganese oxides into silicates. If there be any truth in these considerations then we arrive at the 364 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [ Parr I: conclusion that the alteration of manganese silicates to manganese- ores took place in Archean times, this agreeing with the conclusions reached on page 357. Even if this explanation be true it does not follow that a certain further amount of alteration did not take place in post-Archean times. Indeed it is certain that it has taken place at the outcrops of the gondite series since these rocks were brought to the surface and eroded into their present shape ; and very probable that it is still going on at the outcrops ; but the product of this method of altera- tion is not a compact crystalline ore, but a softish more or less porous one. Depths to which the Manganese-ores extend. If the oxygen in the attacking solutions were really that which was expelled from the original manganese-oxide sediments at the time of their metamorphism into silicates, then it is quite evident that, even though the alteration is of the nature of an oxy-alteration, which is usually supposed to be especially characteristic of the surface, this alteration can have taken place at any depth to which the sediments were buried. It may be that in the deepest parts the pressure was not sufficiently ameliorated for the manganese silicates to have been reconverted into oxide. If so, then perhaps the very bottoms of the synclines have escaped this alteration and retained their silicate character. From this we see that when the bodies of manganese- ore are mined, those that were formed by the direct compression of original manganese oxides without any passage through the silicate stage may be expected to extend to as great a depth as the rocks of the gondite series, namely to the bottoms of the synclinal folds. Whilst those that were formed by the alteration of manganese silicates may also extend to as great a depth as the rocks of the gondite series, except that perhaps the very bottoms of the synclines escaped being converted either partially or completely into manganese-ores. Conclusions as to the Origin of the Gondite Series and the Associated Manganese-ores. The conclusions at which I have arrived in the foregoing pages are much more open to doubt than those regarding the origin of the ores of the kodurite series, the reason being the smaller amount of evidence obtained. The points that may be considered fairly certain are the following :— 1. The rocks of the gondite series are the product of the metamor- phism of the less pure manganiferous sediments of Dharwar Cuap. XVII] GONDITE SERIES : CONCLUSIONS. 365 age, the metamorphism of these sediments having taken place towards the end of the Dharwar period. 2. A portion of the ores has been formed directly by the compres- sion of the purest of the original manganese-oxide sediments. 3. Another portion of the ores has been formed by the subsequent alteration of the manganese-silicates produced by the above- mentioned metamorphism. The points that are to be considered as more doubtful are put forth below. Even if they do not express the whole truth, I believe that they form an approximation to it; anyway, together with the points given above, they form a working hypothesis that will suggest to a future geologist the evidence to look for in trying to put the theory as to the origin of these manganese-ore deposits on a surer footing. 4, The ores formed by the alteration of the rocks of the gondite series were formed by a combined decomposition and replacement of the gondite, spessartite-rock, or rhodonite-rock, as the case may be. 5. The alteration of manganese silicates to manganese-ores took place at the close of the Dharwar period of folding, and hence in Archean times. 6. The alteration took place at considerable depths, so that, taken in conjunction with the supposition that a portion of the ores are merely compressed manganese-oxide sediments, work- able manganese-ores may be expected to extend in some places to as great a depth as the rocks of the gondite series. 7. The alteration was due to the attack on the manganese-silicate- rocks by waters containing either carbon dioxide or sulphuric acid, more probably the former; and also oxygen. 8. The carbon dioxide may have been a portion of that liberated in the conversion of original impure calcareous sediments into the quartz-pyroxene-gneisses of this area; and the oxygen a portion of that liberated in the conversion of original impure manganiferous sediments into the manganese- silicate-rocks. 9. A small proportion of softish and more or less porous ore has been formed since the rocks of the gondite series were exposed at F the suriace, and is probably still being formed. CHAPTER XVIII, GEOLOGY—centinued. Manganese in the Purana, Paleozoic, and Mesozoic Formations. Manganese in the Purdna formations--In the Gondwanas—In the Lias—In the Lametas—In the Deccan Trap. Manganese in the Purana Formations. Manganese has been found in small quantities only in the rock groups classed as the Purana formations. In a few cases it may have been in- troduced into the rock in which it occurs at the time of deposition of that rock ; but in the majority of cases the manganese-ores found in these jormations are of secondary origin and have been formed by the percola- tion of manganiferous waters whilst the rocks lay at the surface, with the infilling of cavities and cracks, or the superficial replacement of rock. The writings of Newbold and Aytoun indicate the presence, in the Manganese in the limestones and quartzites of the Kaladgi series of Kaladgi formation, the Belgaum and Bijapur districts, of numerous veins of manganese-ore (see pages 633 and 640). But Foote referring to the Bijapur district states his inability to find these numerous occurrences of manganese-ore in the Kaladgi rocks (page 641); hence it must be regarded as doubtful if manganese-ores occur in this formation, except perhaps very rarely. Several occurrences of manganese-ores have been found in the rocks Manganese in the Of the Bijaéwar formation, apart from those that are Bijawar formation, obviously the result of replacement or impregnation at the surface outcrops. Thus at Sontulai in the Hoshangabad district there is an occurrence of what seems, although it is not properly exposed, to be a bed of manganese-ore (an inferior wad) intercalated between some quartzose and brecciate rocks that are apparently of Bijawar age. It is not certain, however, that this is a true bed formed at the time of deposition of the enclosing rocks; for this body of manganese-ore may equally have been the result of the replacement, along a line of porosity or brecciation, of the pre-existing Bijawar rocks (page 802). Unfortunately the occurrence is of no economic importance, so that it has not been opened up. A specimen of psilomelane brought from Behat in the Gwalior State came in all probability from this formation. Cuap. XVIII." PURANAS AND GONDWANAS. 367 No certain evidence of the existence of contemporaneously-deposited Manganese in the Manganese-ore in the rocks of the Vindhyan forma- Vindhyan formation. tion has yet been obtained. At Bunkuta near Gohugaon in the Nimar district, Central Provinces (see page 978), however, I have found small amounts of pyrolusite formed at the surface by thereplacement of shales of Vindhyan age. Mr. Datta has found manganiferous hematite of possible Vindhyan age in Rewah (page 690). Since this was sent to the press an occurrence of manganese-ore in the Lower Bhander Sandstone division of the Vindhyans has been discovered in Bhopal, near Konugion village, which is 2 miles west of the town of Bhopal. In the sandstone are numerous bands of conglo- merate, and in this and the sandstone psilomelane occurs in the form of irregular patches. It also occurs as dendroid films in the sandstone and, to a small extent. as a cementing material in the conglomerate. I am not aware if any of this manganese-ore is considered to have been deposited contemporaneously with the enclosing rock or whether it has all been secondarily introduced (see page 672). The occurrence mentioned by Marcadieu of crystals of marcellin Manganese in the (braunite) in a manganiferous and ferruginous lime- Krol formation. stone, near Dharmsdla in Kangra, probably refers to an occurrence of manganese in the Krol formation. Manganese in the Gondwdanas. Manganese in the form of impregnations and stains and even nodules has been several times recorded in the various Gondwana formations. Thus in the Ironstone Shale group in the Burdwan district the iron-ore is constantly manga- niferous, containing about 1} to 24 per cent. of this element (see page 615). In the Kamthi group nodules of psilomelane have been found in clays at Malagarh Hill in the Wun district (see page 979), whilst oxide of manganese is doubtfully recorded as occurring in sandstone of this formation at Silew4da in the Nagpur district’. In the Jabalpur division of the Gondwanas, psilomelane has been found in the form of nodules in clay in South Rewah (see page 690). 1 W. T. Blanford, Mem. G.S.I., 1X, p. 17, (1872). Tronstone shales. Kamthi group. Jabalpur group. 368 MANGANESE DEPOSITS OF INDIA; GEOLOGY, ff Part II: _ Manganese in the Lias, An occurrence is mentioned on page 613 of manganese-ore in a metalliferous vein traversing the Liassic rocks of Baluchistan at Shekhran in Jhalawan. Manganese in the Lametas. In the Dhar Forest and Indore State, Central India, and in the Nimar district in the Central Provinces, the sandstones and conglomerates of the Lameta formation rest on a peneplain of Bijawar, and metamorphic and crystalline, rocks. The former (Bijawars) appear to have undergone a sort of lateritization in pre-Lameta times on lines analogous to the process by which the post-trappean laterites have been formed. This pseudo-laterite has been designated ‘ porous breccia’ by Mr. Vredenburg, and is composed of angular fragments of quartz, hornstone, quartzite, etc., set in a soft porous, loamy, matrix. The lowest Lameta beds probably consist of this porous breccia rearranged by water, so that it is often impossible to decide where the latter ends and the Lametas begin. The argillaceous-sandy matrix of this breccia is often replaced by manga- nese oxides (pyrolusite or psilomelane) so as to yield a breccia of angular fragments of white quartz set in a black matrix of manganese oxide. The Lameta sandstones and conglomerates, where porous, have also often been impregnated by oxides of manganese, and where the sand grains and pebbles were originally set in an argillaceous matrix, the latter has often been replaced by psilomelane. No cases have yet been found of undoubted original manganese oxide in the Lameta rocks, except per- haps in the re-arranged manganiferous breccias sometimes forming the base of this formation; for they may have been rendered manganiferous either before or after the deposition of the Lametas. The ultimate source of the manganese that has brought about the impregnation and re- placement of Lameta rocks is probably to be looked for in the meta- morphic and crystalline rocks in the areas in which these rocks occur. For even if there are no manganese-silicate minerals, properly so called, in these rocks, the ferro-magnesian silicates always contain small quan- tities of this element. As to when the Lametas and porous breccias became impregnated with manganese oxide it is impossible to speak with certainty, but it seems likely that this took place in pre-Trappean times, when the metamorphic and crystalline rocks were uncovered and freely exposed to the action of meteoric waters. For details of Cuap. XVIII. ] DECOAN TRAP. 369 the occurrences of manganese in the Lametas and porous breccias see the accounts given under the headings of the States and districts of Dhar, Indore, and Nimar. Manganese in the Deccan Trap. It is probable that small quantities of manganese are fairly uniformly distributed through the lavas of this formation, these rocks being usually basic. No analyses of these lavas have, however, ever been published, so that it is not possible to say what this quantity will average ; but probably, as is usual in basalts and dolerites, only a few tenths of one per cent. Manganese-ores have been reported to occur in the districts of Amrdoti, Belgaum, Dharwar, Ratnagiri, and Satara, but nothing further has been heard of any of these ores except those of the Satara district. At Mahabaleshwar in this district, where the Deccan Trap formation reaches almost its highest elevation above sea-level, there are several occurrences of concretionary or nodular psilomelane, usually in a red- dish clayey soil. The interesting feature of this occurrence is that the higher parts of the Mahabaleshwar plateau are covered with laterite, in which I was not able to find a trace of visible manganese oxide, the ores always occurring in the above-mentioned soil where it overlies the decomposed trap at the edges of the laterite cap. From the fact that the manganese-ores are sometimes found to contain remains of substances probably once contained in the trap it is probable that the concretions of manganese-ore, and the soil in which they occur, have been formed by the decomposition 7 situ of the trap rocks with the concentration of the manganese. Since, however, the laterite covering most of the higher parts of the plateau must also have been derived from the trap rocks by their chemical alteration, in a way that does not matter here, and since, as already mentioned, this laterite seems to be free from manganese, it is evident that a considerable amount of manganese must have been removed in solution from the trap rock from which the laterite has been produced. It may be that this manganese has also found a resting place in the soil resting on the decomposed surface of the trap. If this be the case then the manganese concretions in this soil may have derived their manganese from two distinct sources, namely (1) from the rocks by the decomposition of which the soil has been produced, and (2) from the masses of rock from which the laterite of the higher parts of the plateau has been formed. For further details about these occurrences of ore, see the account of the Satara district (pages 661— 668). 0 K CHAPTER XIX. " @HOLOGN-contnaed: Manganese in Laterite. General—Low-level late1ite—High-level laterite—Theories as to origin of high- level laterite—The Yeruli laterite—Lateritic manganese-ores—Lateritoid—The Talevadi occurrence—Jabalpur and Gua—List of localities—Economic value— Sandur—Distribution—Structure and working oi—Mineral composition—Chemical composition. General. In many parts of India the geology is obscured by an overlying cover- ing or cap of a curious rock characteristic of tropical climes. This rock A consists essentially of a mixture of hydrated Origin of the term. ; : : f 2 oxides of iron and alumina, with often a con- siderable percentage of titania. It is the rock known to Indian geolo- gists as laterite. This word and its latin equivalent, lateritis, both meaning literally brick-stone, were invented by F. Buchanan, F.R.S., being derived from the Latin word Jater, a brick, in allusion to the custom of cutting this rock into the form of bricks for building purposes ; this is on the analogy of several South Indian vernacular names also meaning brick-stone. Much attention has been devoted to the study of this rock by Indian Division into low and geologists, and it is evident from their writings, high-level laterites. that there are several varieties. Nevertheless, they can all be classed into two main divisions. These two divisions are the low-level laterite and the high-level laterite : and it was to the low-level varieties of the Malabar coast that the term laterite was first applied by Buchanan, the extension of the term to include the high-level varieties being due to subsequent writers. This classification depends solely on the elevation at which the rock is found and is quite independent of its origin. Nevertheless, it so happens that the larger proportion of the low-level laterite is partly of detrital origin, and the larger proportion of the high-level laterite of non-detrital origin. Low-level Laterite. The low-level laterite is found mainly in the low-lying coastal region on the east and west sides of the Peninsula. Perhaps the larger propor- tion of low-level laterite is of detrital origin and formed by the mechanical 1 «4 Journey from Madras through the countries of Mysore, Canara, and Malabar,’ II, p, 441. London, (1807), Cuap. XIX.] HIGH LEVEL LATERITE, 371 disintegration and transportation of laterite from higher levels by the agency of water, to be deposited at lower levels as low-level laterite. As a consequence of its mode of formation, materials derived from the mechanical disintegration of other rocks than laterite get mixed with the detrital lateritic materials in the formation of low-level laterite. Hence, low-level laterite may contain many other substances besides those men- tioned above as characteristic of laterite, and of these extraneous substances fragments of quartz are perhaps the commonest; in any case the low- level laterite on analysis would usually be found to contain a considerable amount of silica, whilst the true high-level laterites are usually compara- tively free from silica, either free or combined. The whole is cemented together by segregative and chemical changes taking place in the ferruginous materials of the deposit, probably with the addition of a certain amount of ferric oxide deposited by percolating waters. The best account of low-level laterite that has been published is contained in P. Lake’s paper on the geology of South Malabar!. From this it appears that there is a considerable amount of low-level laterite of non- detrital origin, formed, according to Lake, by the decomposition in situ of Manganese-ore in the underlying gneiss witha certain amount of re- low-level lnterite. arrangement by rain, etc. No account of the laterite of Goa seems to have been published ; but I have recently been able to examine it in several places, and think that practically all that I saw was of non-detrital origin and formed at least in part by the replacement of the underlying rocks. In some places it is free from visible manga- nese-ore, in others it contains spots and patches of manganese-oxide of no value, whilst at quite a number of localities it is highly manga- niferous and worked as asource of manganese-ore. The laterite seemed very similar to the high-level laterite of Talevddi in Belgaum. High-level Laterite. The high-level laterite is found best developed on the plateau known as the Deccan, and further north in the Central Provinces and Central India. It seldom occurs at levels lower than 2,000 feet and never at elevations greater than about 7,000 feet?. A small portion of it is 1 Mem. Geol. Surv. Ind., XXIV, pp. 217-233, (1891). 2 This figure is given on the assumption that true laterite exists in the Nilgiri Hills and Palni Hills. If, however, Medlicott and Blanford are correct in their statement that no true laterite occurs in these places, then the upper limit must be given as about 5,000 feet. Since this was written I have been able to visit the Nilgiris. I found the surface rocks to bhe—where not the gneisses of the charnockite series—lithomarges and clays of various colours, sometimes with associated ochres. Where I happened to go laterite was rare ; but in one or two places | found rocks to which it seemed to me this term could fairly be applied. II K 2 372 MANGANESE DEPOSITS OF INDIA: GEOLOGY. f Part II: of detrital origin, having been formed by the denudation and reconsoli- dation of the typical rock ; but there is no need to consider this detrital variety of high-level laterite here, except to say that it is often litholo- gically indistinguishable from the true low-level laterites. The origin of the high-level laterites is a much debated question, con- cerning which many hypotheses have been advanced. This divergence of opinion is partly due to the fact that this rock is eminently susceptible of segregative changes, which produce a constant rearrange- ment of its constituents with the obliteration of all original structures ; and partly due to what seems to be a fact, namely that two distinct South Indian types of rock have been designated by the term variety of high-level ‘ high-level laterite’. With regard to one of these laterite. Medlicott and Blanford remark !:— ‘ ferruginous clays, with but little of the true character of luterite, and due solely to the decomposition of gneissic rocks, have b2en ocecasionily described under the name. uch is certainly the case with the Nilgiris, one of the localities mentioned by several geologists. No well-authenticated occurrence of laterite is known at an elevation exceeding 5,000 feet ubove the sea’. Dr. Holland 2, however, whilst aware of this passage, prefers to regard this rock as laterite. Such laterite, as might have been anticipated from its mode of derivation, often contains a considerable amount of silica, both free and combined. It seems to prevail in the areas occupied by the gneissose and crystalline rocks in the southern parts of the Peninsula, and often preserves the original structures of the underlying rock, pisolitic or concretionary structures being rare 3, The second type of high-level laterite is that which occurs in the The Deccan variety form of horizontal caps, resting usually on rocks of high-level laterite. of the Deccan Trap formation, but not infrequently on older rocks, especially the Dhérwars. Those patches not actually on the Deccan Trap are usually situated near, but sometimes at great distances from, the present edge of this formation. This type of laterite does not show any structures that can be compared with corresponding structures in the underlying rock, and is not infrequently markedly pisolitic. The impression conveyed by the appearance of the often vertical scarps of this rock, particularly when the underlying rock is trap, is that there is not a gradual downward passage from completely-formed laterite into 1 «Manual of the Geology of India’ (1879), p. 356. 2 Geol. Mag., Dec. IV, Vol. X, p. 63, (1903). 3 I did not myself happen to notice any laterite in the Nilgiris that preserved the Original structure of the gneissic rocks. ‘The materials that did show this were the ferruginous clays (and lithomarges) referred to by Medlicott and Blanford, Cuap. XIX.] ORIGIN OF LATERITE, 373 the fresh underlying rock, with an intermediate stage of rock in a state of partial decomposition ; but that the laterite is a distinct formation resting on the underlying rock with no necessary connection between the two. This is the type of laterite that is often so aluminous as to be bauxite. It is also very free from siliceous matter, either free or com- bined. The best account of the structure and appearance of this type of high-level laterite is the account of the laterite of Bidar by Newbold !. Theories as to the Origin of High-level Laterite. The following is a list of some of the many theories that have been propounded to account for the formation of high-level laterite :— 1. H. B. Medlicott and W. T. Blanford 2 in discussing this subject consider two possible methods of derivation : namely, ‘that the high-level laterite is simply the result of the alteration an situ of various forms of rock, and especially of basalt, by the action of atmospheric changes’; and that it may be a sedimentary deposit. They conclude that in spite of the large amount of work that has been done on the subject, it is im- possible to say that either of these is the true theory, as there are objections to them both. 2. F. R. Mallet 3 suggests the hypothesis that the high-level laterite may have been formed in lakes occupying shallow depressions formed on the surface of the Deccan Trap formation at the close of the period of its eruption ; during the decay of vege- table matter in contact with disintegrated ferruginous rocks, iron passes into solution as ferrous carbonate; partly in streamlets on the way to the lakes, and partly after reaching them, the ferrous carbonate is subjected to oxidizing influences with the precipitation of hydrated ferric oxide; whilst a further portion may be precipitated by the action of various organisms, especially alge, the pisolitic structure being due to deposition round a nucleus 4. The mode of formation 1 Jour, As. Soc. Beng., XIII, pp. 989-994, (1844). 2 « Manual of the Geology of India’, pp. 359-364, (1879). 3 Rec. G. S. I., XIV, pp. 145-148, (1881). 4 Or to subsequent segregative action. With regard to the part that alga may play in such a process it is interesting to note that according to G. Bertrand, Revue Générale de Chimie, VIII, p. 211, (1905), Jackson has described three sorts of Crenothrix, “C. Kiihniana (ou polyspora) qui sépare oxyde de fer ; C. ochracea, qui sépare V’alumi- nium avec un peu de fer ; et C. manganifera, qui sépare le manganése’. _To the original paper in Zettsch, Untersuch. Nanrungs-u. G. Mittel, VU, pp. 215-221, (1904), I have not been able to refer. 374 MANGANESE DEPOSITS OF INDIA; GEOLOGY, [ Part II: on this hypothesis is thus analogous to that of the Swedish lake ores in process of formation at the present day. 3. T. H. Holland !, writing from experience of the Southern Indian laterites, suggests that the rock is formed in situ, the energy necessary for the breaking up of the silicates being derived from the vital action of organisms, ordinary and special. He further explains the development of concretionary structures by suggesting that ‘in compounds where a constituent is loosely held, the “crystalline affinity” by which physical molecules tend to unite and form crystals may be more energetic than the chemical affinity’. 4. E. W. Wetherell 2, writing particularly of the Bangalore and Kolar districts in Mysore, supposes that the laterite of this area is of detrital origin and was formed by the washing of the decomposed surface detritus of the surrounding elevated ground into a lake, where it got mixed with non-lateritic material only to a small extent, and was subsequently cemen- ted by the action of segregative tendencies, due to the pre- sence of some organism in the lake, such as one allied to Gir- vanella. As Mallet also allows for the washing of detritus into his lakes, this theory is only a variant of Mallet’s, giving the preponderance to mechanical instead of to chemical deposition. 5. Lastly J. M. Maclaren has recently published a paper 3 in which, relying mainly on a very clear section at Talevadi in the Bel- gaum district, he advances the view that lateritic deposits are derived from mineralized solutions brought to the surface by capillarity, and, are essentially replacements (either mechanical or metasomatic) of soil, or of rock decomposed in situ, or of both; the contents of the solutions being derived from the rocks at and near the surface. The Laterite of the Yeruli Plateau. Leaving out of consideration the high-level laterite deposits of the first type, of which I have had no field experience, and also passing over 1 Geol, Mag., Dec. TV, Vol. X, pp. 68-69, (1903). 2 Mem. Mysore Geol. Dep., Ill, Pt. I, pp. 24-27, (1906). 3 Geol. Mag., Dec. V, Vol. III, p. 546, (1906). Cuap. XIX. ] ORIGIN OF LATERITE, 375 for the present the question of the source of the energy necessary to bring about the decomposition of the rocks from which laterite is either proximately or ultimately derived, it seems to me that the truth lies in a combination of the various theories mentioned. In the first place, judg- ing from my examination of the Yeruli plateau, in the Satara district, I do not think that Maclaren’s replacement theory can be by any means generally applicable. This plateau is composed of a sheet of laterite, which happens to be very alummous. At the north-eastern edge of the most easterly of the three caps into which the laterite has been cut, there is a conglomerate bed forming the topmost layer. It is composed of pebbles of pale buffish and pinkish bauxite set in a matrix of very ferruginous laterite, almost entirely pisolitic. This conglomeratic layer is about one foot thick, and rests on a layer of solid bauxite at least 2 feet thick, of precisely similar character to the pebbles contained in the topmost layer. This bauxite bed is not continuous for any great distance, but passes horizontally into ferruginous laterite. In other parts of the plateau some of the pebbles contained in this conglomerate are composed of the ferruginous laterite. From this occurrence there seems to be no doubt that before the end of the period during which the laterite of Yeruli was being formed, there was a break in which the already-formed laterite was subjected to denudation, with the production of the pebbles referred to above. It is difficult to imagine that these pebbles were cemented into the conglomerate by the process cf deposition of oxides of iron brought up from below by capillary forces stimulated by surface evaporation ; for, if so, how could the underlying bauxite have escaped being impregnated with, and partly replaced by, iron oxide, apart from the difficulty of imagining the actual way in which such cementaion could have taken place? It seems to me that the only The cenglomerate POSsible way of explaining the cementation of the formed beneath water, pebbles is to suppose that it took place beneath Sees es ne: water, such as at the bottom of a lake. After the pebbles of bauxite had been formed by the action of running water, such as in a river valley, it is easy to imagine the formation of a lake, with bauxite pebbles lying on its bottom. We can suppose that the waters entering the lake contained salts of iron in solution derived from the sur- rounding ferruginous basaltic rocks, and that hydrated ferric oxide was precipitated in the lake, where it formed a cement for the pebbles, the pisolitic structure of the cement being due, either to deposition in this way round a nucleus, or to concretionary action. If then this ferruginous A bauxite-conglomerate. 376 MANGANESE DEPOSITS OF INDIA’ GEOLOGY. [ Part II: cement was formed under water in a lake (or perhaps in a marsh orbog, why should not the remainder of the lateritic layers at Yeruli, which are usually non-pisolitic, have been formed in the same way? They may have been ; but that they were more probably not is indicated by the fact that there is apparently a gradual passage downwards from the laterite into the underlying rock, as will now be noticed. It so happens that a large number of pits were sunk on this plateau in former times by the natives of these parts, it is said in search of copper; but much more probably for the extraction of the iron, although for this purpose they seem to have chosen a particularly aluminous mass of laterite. One of these shafts had been cleaned up just before my visit and deepened a little. It went through 38 feet of laterite, both aluminous and ferru- ginous, and then passed into a soft lavender-grey rock. On account of the presence in this rock of soft white spots, resembling in size and Comipdaition: abundance those frequently seen in the amygdaloidal earthy traps of the region, we can suppose that it was derived from such an amygdaloidal earthy trap by some method of chemical alteration. The composition of this altered rock is shown by the following partial analysis carried out by 8. Sethu Rama Rau, Sub-Assistant in the Geological Survey :— Mahabaleshwar. Yeruli. Si02 5 : ‘ 3 : : 35°60 38:98 “i Al203 : mare re 35°51 | 35°05 Fe203 + TiO2 ; ; ; ‘ ; 16°91 | 15°81 Undetermined c 4 . . ‘ 11°98 10:16 a “100-00 | 10°00 The analysis shown in the first column was also made by Sethu Rama Rau, on a sample of very similar material obtained near the lake at Mahabaleshwar at its eastern end. The similarity of these two analyses is very fwiking. Cuap. XIX, ] ORIGIN OF LATERITE, | 377 The composition of the fresh rock is, of course, unknown ; but it can- not have been very different from that of a basalt (or andesite'). From the analyses of andesites and basalts given on pages 250, 251, 253, and 259 of Cole’s ‘ Aids to Practical Geology ’, 1898, I have extracted the following figures for the limits of composition of these rocks :— Andesites. Basalts. ot Sig . ; : R ; 5 : 56°2—69:0 44-2 54:0 i Ti0g . we, eee 08 15— 3:1 WR MNOa ts Se, : 14:3—16'9 96—18°5 Fe2.03 + FeO ee eS S7—152 11°6—15-4 MnO 2 F : 3 , trace — 0°5 0-3 ee ee ee a 32 70 8°6—10°4 egw! FL. 0'8— 4:8 3'8—10'1 eee ene ALA ey ln 0-9— 2:9 ae a lala ga ee ae 25— 50 1-1— 2-5 H20 MMOS Bap AST ts 0-3— 11 13— 25 Three specimens of the Yeruli bauxite, taken by the late Mr. L. C. H. Young (by whom I was accompanied on my visit to this locality) as duplicates of specimens collected by me, were analysed by Messrs. J. 1 T have considered the possibility of the rock being an andesite, because there are some ash-like layers in the traps of this region. Theircomposition has not been investi- gated. but they may be as acid as andesites; and if so, it is possible, though net very probable, that some of the earthy amygdaloidal beds, also, were, when fresh, andesites rather than basalts. 378 MANGANESE DEPOSITS OF INDIA: GEROLOGY, f Parr II; and H. 8. Pattinson of Newcastle-on-Tyne, on behalf of Messrs. C. H. B. Forbes & Co. of Bombay, with the following results! :— A.690 A.691 A.693 Siz ee eee AlgO3 - : 5 ; - 5 -| 46°32 | 54°10 57°48 Fe203 - : - : : ; elo 36 6:18 4-61 TiOz - 5 . - : : : : 5°60 | 6°50 6°55 Cr203 5 - - : - ‘ ; 0°63 trace | 013 CaO : ‘ « : - - . ; nil nil nil MgO 4 - : : 5 - : 2 0°29 | 024 =| 0-07 SO2 J F 3 P 4 $ x oor, | nil nil P205 : - ° . . 2 : 0°22 i 0715 0°08 H20 (combined) - : - - : : 2451 | 27°60 29°66 Moisture - ~ - - - “ : 040 0-10 0°40 =) 7 ) ; 10003 | 10007 ~~ 100708 vit. From the foregoing analyses it is at once evident that there is a sort of progressional change in composition from that of the original basalt (or andesite), through the decomposed lavender-grey rock. to that of baux- ite. This change takes the form of an increase in the amounts of alumina, titania, and water, with a decrease, amounting to almost total disap- pearance, in the quantity of silica, lime, magnesia, and alkalies. Had an analysis been given of one of the ferruginous varieties of laterite, it would have been seen that there is an increase in the quantity of iron oxide also. In this case, as with the bauxites, it probably would have been found that manganese was absent. It can be considered almost certain that the soft lavender-grey rock, judging from its structure and composition, is an altered amygdaloidal earthy trap, but it does not neces- sarily follow from the analyses given above that this altered rock passes gradually into laterite. In the pit mentioned above, however, there 1 Published by the kind permission of this firm. 9 Cuap. XIX.] ORIGIN OF LATERITE, 379 seems to be some such passage. Moreover, several other cases of apparent passage of underlying rock into laterite have been noticed by previous writers, an especially clear example being the one recently figured by Mr. Maclaren (see page 384). It is precisely with regard to the nature and reality of such passages that opinions differ. It is generally accepted that the materials com- posing the type of laterite now being discussed have been derived in some way from pre-existing rocks, usually basic lavas of the Deccan Trap formation. It is also generally recognized that the formation of this type of laterite involves the disappearance, probably in solution, of the silica, lime, magnesia, and alkalies, of the original rock, with the concentration of the oxides of aluminium, iron, titanium, and sometimes Origin of the Yeruli Manganese, to form laterite; this result of general laterite. experience agreeing with the particular case of Yeruli, as illustrated by the analyses given above. But, as can be seen from pages 374-5, there are many theories as to the method by which this result may have been produced. Each of these explanations may be true as applied to some particular deposit of laterite; but in “many cases a combination of them will probably be nearer the truth. In the particular case of Yeruli it seems necessary, as already explain- ed, to adopt Mallet’s explanation with regard to the uppermost layer of laterite, namely that containing pebbles of bauxite. But, because of the difficult of accounting for the alteration of the underlying rock, with- out hypothecating the downward percolation of mineralized solutions, of which there is no sign, this explanation cannot be extended to the whole mass of laterite. For exactly the same reason Wetherell’s theory is put out of court. This leaves the theories of Holland and Maclaren. It is very difficult to say which, if either of these theories applies to the case in question. Seeing, however, that the altered lavender-grey rock inter- vening between the laterite and the underlying trap is shown by analysis to be particularly aluminous and thus to correspond in chemical character with the prevailing nature of the overlying laterite, I am inclined to think that the rock was decomposed in situ with a gradual passage into the aluminous laterite. Had the laterite been formed in accordance with Maclaren’s theory, there is no reason why the aluminous laterite should have been deposited just where the underlying rock happens to be particularly aluminous. For the rocks of this area are at least as ferru- ginous as aluminous, and consequently the circulating solutions that formed the laterite cap by replacement of the decomposed rock would probably have deposited a more ferruginous type of laterite. Whether, 380 MANGANESE DEPOSITS OF INDIA: GEoLocy. [Part II: on the other hand, it is necessary to attribute this formation of laterite in situ to an organic agency, as suggested by Holland, instead of to the action of ordinary chemical processes due to weathering, asin the usual theory of formation by alteration im situ (as noticed by Medlicott and Blanford), I do not feel in a position to judge. Apart from this point, we arrive at the conclusion that the lower portion of the laterite of Yeruli was formed by the decomposition of basic lavas in situ, and the upper by deposition in lakes or bogs, after a period of denudation. I have discussed this case in such detail, partly to indicate the ex- Noccstity “of consilenngae home difficulty of the question of the origin of each occurrence of laterite laterite, and partly to indicate that, in all pro- Pepe ey: bability, no one explanation will apply to all varieties of high-level laterite, and that it is necessary to consider each case separately. Perhaps, after a considerable number of cases have been so discussed, we shall be in a position to form a truer idea as to which of the various theories here considered accounts for the greater proportion of the occurrences of high-level laterite. Lateritic Manganese-ores, But whatever the mode of formation of this high-level laterite may Result of formation of be, the result, already stated on page 370, is laterite. certain, namely the formation of masses of rock composed essentially of oxides of iron, aluminium, and titanium, usually associated with a large amount of combined water; the silica, lime, magnesia, and alkalies, of the rock from which the former constituents The destination of man- Were derived having been eliminated. Up to ganese when laterite is the present I have omitted to refer to what tone becomes, during the formation of laterite, of the small quantities of manganese that are contained in almost all the rocks of the earth’s crust. When, in the course of the decomposition of the rocks in the area where lateritization is going on, the oxides of iron and aluminium pass into solution!, it is probable that soluble salts of man- ganese are also formed and dissolved ; these salts being in all probability either the bicarbonate, or combinations with various organic acids such as are often found in soil where vegetable matter comes into play. As I have already noted in a paper? treating of the association of gibbsite 1Itis to be noticed that, even in the case of laterite formed by decomposition of rock in situ, the oxides of iron and aluminium must have passed into solution at least for a short while, as is evidenced by the fact that laterite seems always to have been reconsolidated throughout and chemically rearranged. 2 Rec. G. 8. I., XXXIV, p. 168, (1906). Cuap. XIX.] MANGANESE IN LATERITE. 381 with manganese-ore at Talevadi, manganese, when present in laterite, usually renders itself conspicuous by segregating into forms, as a rule black nodules or veins of psilomelane or pyrolusite, that one would with- out any hesitation call manganese-ore!. It rarely seems, except in very small quantity (or in proper manganese-ores), to become blended with the other constituents of laterite, so as to form intimate mixtures similar to those that the oxides of iron, aluminium, and titanium, so commonly form with one another. Indeed, many large masses of laterite can be found, as for example, at Mahabaleshwar and Yeruli (see page 375), that seem to be completely free from manganese. As it cannot be supposed that the rocks from which the iron and alumina of the laterite were derived contained no manganese, it is necessary to suppose that with solutions containing manganese, iron, and aluminium, a_ selective precipitation can take place in Nature, analogous to that by which iron and aluminium are precipitated together in the course of chemical analysis, whilst the manganese remains in solution. Nevertheless, in the two cases mentioned above (Mahabaleshwar and Yeruli), we can point to the possible destination of the missing manganese ; namely the concretions of psilomelane found in the ferruginous soil resting on the Deccan Trap lavas near the edges of, but at a lower level than, the base of the laterite caps (see page 369). In some cases, however, the manganese has remained in the laterite in the form of nodular concretions set in a matrix of ferruginous laterite. Of the many occurrences of lateritic manganese-ores that I have been able to examine, only three were in what would be called ‘ laterite ’, without any hesitation, by all geologists. These three were in the low-level laterite of Goa; in the high-level laterite of Talevaddi in Beigaum ; and near Gosalpur in the Jabalpur distrit in laterite that must, I suppose, be called ‘ high-level ’, although it is only at a level of about Lateritoid. 1 It was after Part II of this Memoir was sent to the press that I visited the manganese occurrences of Sandur, Mysore, Goa, and the Nilgiris. Hence I have found it necessary to modify this chapter considerably in places; should any apparent inconsistencies be detected they must be excused as due to alterations and additions made whilst this part was in the press. The statement made in the text relative to the separation of manganese from iron and aluminium still holds as regards the true high-level laterites. In the lateritoid occurrences noticed on pages 381—386, however, the separation of manganese and iron is not always so distinct, Thus I have found in Mysore manganiferous limonite with the manganese apparently uniformly distributed through the limenite so as not to be visible as a separate constituent; but it may still be stated that as a rule manganese, if present, renders itself conspicuous by segre- gating into veinlets and patches of some manganese-ore such as psilomelane or pyrolusite. 382 MANGANESE DEPOSITS OF INDIA; GEOLOGY. [Parr II: 1,300 to 1,400 feet. The remainder occ. in a rock that some geolo- gists would probably, designate ‘laterite’; but others would pro- bably object to the application of the term, The rock to which I refer has a lateritic aspect and usually consists of a cavernous mixture of various oxides ot iron, chiefly hard limonite, yellow ochre, and soft hematite, When no other constituents are present, the rock often resembles typical laterite in its structures and mineral composition so closely that when detached from its rock masses it could not be distinguished from pieces of ordinary ferruginous laterite (of non- detrital origin). Fairly often, however, it contains ores of manganese, either wad, psilomelane, or pyrolusite. The iron-ores and manganese- ores are mixed with one another in very irregular manner. Veins and patches of the manganese-ores sometimes occur in the iron-ores, whilst in other places veins and patches of iron-ores occur in a mass consisting chiefly of manganese-ores. Owing to the cavernous charac- ter of the rock the limonite and psilomelane have often been able to develop marked concretionary structures, such as botryoidal or stalac- titic, whilst the pyrolusite is often in small crystalline aggregates. This rock does not always consist entirely of iron and manganese- ores. It often contains patches of quartz, quartzite, slate, or phyllite. Examination with the microscope shows that these rock patches are residual pieces of rock set in a matrix of ore, and that the latter has evidently been formed by their replacement. Examination of the masses of rock in the field, especially as revealed in the workings for manganese confirms this deduction, and shows that there is a down- ward passage from the lateritic mass of iron- and manganese-ore at the surface through rock containing more and more quartzite, slate, or other rock, and less and less ore, to a rock that is free from all signs of ore The junction between the overlying lateritic mass of rock and the rock on which it rests is consequently an extremely irregular one. There is, in my opinion, no doubt that these lateritic masses have been formed by the metasomatic replacement of the quartzite, slate or phyllite, accompanied by segregative changes. And as these rocks do not usually contain more than a very small proportion of, and often no, manganese, it is evident that the manganese must have been largely brought in from outside by percolating waters, with the resultant repla ement from the surface downwards of the particular rock that happened to be at the surface where the replacement wook place, These lateritic replacement deposits nearly always occur as cappings to small hills, the actual rugged surface of the rock (often spotted CHap. XIX.] MANGANESE IN LATERITE, 383 with lichens) being approximately horizontal. These caps do not, however, show signs that they are the remains of a horizontal sheet, for they occur at different elevations on neighbouring hills, and as noticed above have a very irregular base. And although there are doubtless many cases where such a cap has been cut into two by erosion, yet most of the occurrences suggest that they have been formed independently of other masses of this lateritic rock. On account of the limited extent of each of these masses of rock, their different elevation, their want of horizontal bases, and the numerous cases in which the rock contains residual angular fragments of other rocks, most geologists would probably prefer to consider these occur- rences as distinct from the masses of typical laterite occurring in horizontal sheets, often of considerable extension, and free from included fragments of rock different in character from the laterite. For this reason I propose to refer to these occurrences under the name of Jateritoid, to indicate their similarity to laterite. It is to be noted that, were they to be designated ‘ laterite ’, they would by their position come into the high-level laterite division. From what I have written above it is evident that my view of the origin of these masses of lateritoid and their included manganese-ores is practically identical with Maclaren’s theory of the origin of laterite in general. He bases his theory particularly on the occurrence at Talevadi in Belyaum, I have visited this occurrence myself, and although the sections were no longer so good as when Maclaren went, yet I saw sufficient to make me agree with his description of the occurrence. Although the occurrence was in an area where the laterite seemed to occur as a large spread, yet I could not see any difference between the mode of occurrence of the manganese-ores here and those in the lateritoid deposits. From this it will be seen that the Talevddi occurrence may be regarded as a connecting link between the lateritoid caps containing manganese-ores and the large spreads of high-level laterite usually free from manganese-ore. I think, however, it is more closely related to the lateritoid occurrences than to the large spreads of high-level laterite in which bauxite is so often found. In fig, 22 I have reproduced the Talevddi section given by Maclaren, and cannot do better than quote here his description of it!:—— The Talevadi occurrence. ‘ There, pits in search of manganese expose the laterite in process of formation and give sections of some 30-40 feet in depth. The bottom of a typical section PR ean a Sir ae Sve ee 7 ee ee 1 Geol. Mag., Dec. V, Vol. III, pp. 527, 538 (1906). 384 MANGANESE DEPOSITS OF INDIA; GEOLOGY, [ Part II: shows a white decomposed friable sandy rock which, from exposures elsewhere, is regarded as a decomposed biotite-quartz schist. This passes upward without any abrupt change through a buff sandy clay toa reddish buff, soft rock containing small indistinct ferruginous secretions and minute manganese nodules. As the surface is approached the rock gradually acquires depth of colour, while the con- tained manganese secretions become larger and better defined until, at the surface, they are 2 to 3 feet across with @ like depth. With increase of ferruginous content, the rock becomes so hard that, at the surface, it is often necessary to use explosives to disintegrate it. A few feet below it can be cut with a spade. Through the manganese secretions there ramify veinlets of gibbsite....” . . - - ° MPO’ 55e ie) 8 . WSS ra v°q Fic. 22.—Typical Section of Laterite, Talevadi, Belgaum. (1) Psilomelare with gibbsite veinlets. It is interesting to note that in the Jabalpur district, the main portion of the ores has been formed by superficial replacement of slates and quartzites, and is to be classed as lateritoid ; but there is also some laterite (at Gusalpur) in which pyrolusite is in places found. In Goa some of the manganese-ore is in the laterite itself ; but the quarries for manganese also show that the manganese extends into the under- lying Dharwar rocks, where it has evidently beer formed by the same process of superficial replacement. There seems, moreover, to be a passage upwards from the quartzite or slate through the mixture of manganese-ores or iron-ores, and residual quartzite or slate, to the overlying laterite. This overlying laterite, which is Jabalpur and Goa. Cuap. XIX.] MANGANESE IN LATERITE, 385 spread over many square miles of country, has thus, although from its position low-level, probably been formed, at least in part, by replacement of the underlying rocks accompanied by the usual segre- gative changes. From this we see that this low-level laterite is of the same origin as the rock I have called lateritoid. In the following list, I classify the occurrences of manganese-ore List of occurrences of found in association with lateritic rocks :— lateritic manganese -ores. TABLE 23. Classification of the deposits of lateritue manganese-ores. I.—In low-level laterite :-- 1, Goa. 2. Chengalput. I.—In high-level laterite :—— (a) On the Deccan Trap :— 1, Bidar. 2. Bijapur (Ingleswara), (b) On the Dharwars :— 1, Talevadi in Belgaum, - I[I.—In lateritoid (always on the Dharwars) :— 1, Bengal :—Singhbhum. 2. Bombay :—Dharwar, North Kanara, 3. Central Provinces :-—Jabalpur. 4. Goa. Madras :—Bellary, Sandur. 6. Mysore :—Chiialdrug, Kadur, Shimoga, Tumkur. IV.—In lateritic soil resting on the Deccan Trap :— 1, Satara, V.—Exact mode of occurrence unknown :— 1, Morbhanj. The Talevadi occurrence should really be classified with the lateritoid. The Satara occurrences are noticed under the heading of ‘ Deccan Trap ’ (page 369). All the occurrences of manganese-ore in lateritoid noticed above have been made the object of prospecting operations. In all these areas the work has revealed the presence of deposits that Economie value of the are of value when the price of manganese is deposits. as high as it was in 1906 and 1907; but under ordinary circumstances most of these deposits are of too irregu- lar occurrence and too low grade to be of much value, unless a demand for manganiferous iron-ores can be found at the same time. OU II L 386 MANGANESE DEPOSITS OF INDIA; GEOLOGY. [Part IT: The only lateritoid deposits that it may pay to work at times of low prices are those of Sandur, and some of those of Mysore (particularly Kumsi), The names given in italics show the areas from which ore has been exported. The inclusion of the Sandur deposits amongst the lateritoid ones may give rise to some surprise, consider- ing their enormous size as compared with the majority of the late itoid deposits, It is my opinion, however, that the Sandur deposits—certainly those of the Ramandrug area, and pro- bably those of the Kamétaru area—have been formed by the same process of superficial replacement of rocks containing but little manganese, I do not propose to go further into the mode of origin of those and other lateritoid deposits in this portion of the Memoir ; but for further details I would refer the reader particularly to the accounts of the Sandur deposits given in Part IV of this Memoir, and also to the accounts of the Mysore and Jabalpur deposits. Some of those who may object to the deposits I have termed eae lateritoid being regarded as a variety of imitation of the term : ; C ‘jateriforde: laterite may say that, if superficial replace- ment deposits of iron and manganese are to be called lateritoid, it will be necessary to extend the term to ores of other metals that have been furmed by similar processes, such as may occur in fissure veins, near the surface. This may be avoided by restricting the term to replacement deposits of the oxides of iron, manganese, aluminium, and titanium, the four constituents character- istic of the true high-level laterite, Although, as mentioned above, many masses of laterite are apparent- ly quite free from manganese ; and although the manganese when present has probably been concentrated by segregative processes, so that the manganese froma considerable area of ground has been formed into Distribution of mangani- Concretions distributed overa much smaller ferous laterites, and lateritoid. area of laterite : yet one would expect the man- ganiferous laterites (and lateritoid) to bear in general mode of occurrerce some relation to the nature of the underlying rocks, and hence to be found in those areas where the older rocks are the most highly manganiferous. Such is found to be the case. Laterite found on the Deccan Trap, the rocks of which contain only a com- paratively small amount of manganese, is, as far as is known, fairly free from any manganese-ores, the Bidar occurrence being the most notable exception ; whilst laterite and lateritoid found on the outcrops of rocks The Sandur deposits. Cuap. XIX.] MANGANESE IN LATERITE 387 of the Dharwar series, which is the manganese-ore bearing series of India par excellence, is often very rich in this mineral. The similarity between deposits of manganese-ore in the true laterites, as in Goa and Belgaum, and those in lateritoid, as in Mysore, is so great, that the remaining paragraphs of this chapter can be taken as applying to both, bearing in mind that the Sandur deposits, and that of Kumsi in the Shimoga district of Mysore, are not typical of the whole. Since the manganese-ores found in laterite usually take the form The structure and work. Of boulders, nodules, and other concretions, set ing of the lateritic manga- jn a matrix of ordinary ferruginous laterite, it “Ses a follows that in working them there will be a much larger proportion of waste per ton of ore extracted than in the case of solid bodies of ore, such as some of those of the Dharwar type being worked in the Central Provinces. But this disadvantage is to a certain extent neutralized by the fact that the lateritic ores, owing to the comparative softness of the matrix in which they are set, can usually be quarried with greater ease than the massive ores of the Central Provinces. The lateritic deposits are further distinguished from those of the Dharwar type by the fact that laterites and lateritoid, the rocks in which they occur, are only found at the surface, where they are disposed in more or less horizontal masses tending to be bed-like; these, as mentioned on a previous page, are rarely of a greater thickness than 100 feet, and usually much less. The distribution of the concretions of manganese-ore is, moveover, very irregular, so that a given mass of laterite or lateritoid may be very rich in ore at one point, and close by contain insufficient ore for the deposit to be worth working. The consequence is that the lateritic deposits are of much more uncertain character than the deposits of the bedded type, as exemplified by the Dharwar deposits of the Central Provinces; and hence of much less value. The manganese-ores found in laterite and lateritoid usually consist either of psilomelane, or of pyrolusite, or of mixtures of the two. With The mineral composition these, limonite and ochreous hematite are often of the lateritic ores. intimately associated ; and, when the iron-ores cannot be readily cleaned away, the manganese-ores are rendered valueless, unless a market can be found for manganiferous iron-ores containing a comparatively small amount of manganese. The. psil- omelane is often concretionary in shape, being either reniform, botryoidal, or mammillated. Sometimes it is compact and at other times caver- nous. The cavities in the latter type of ore are sometimes lined with Tienes 388 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [ Part II: smooth botryoidal crusts of the same mineral and at other times with radiate crusts of a mineral that has not yet been critically examined, but which is in all probability altered manganitel. The pyrolusite may also be either compact or cavernous, the cavities usually being lined with crystals of the same mineral. At other times the ores are indefinite soft varieties that can only be designated wad. There is also a hard light grey crystalline mineral found associated with the other ores, particularly in Mysore and Sandur; this has not yet been identified, and is not certainly always the same mineral, In some cases it seems to be probably polianite. Of the various ores mentioned, psilomelane is undoubtedly the commonest. The nodules of this, when broken open, are frequently found to exhibit concentric structures, bearing witness to the way in which they were formed, namely by the deposition or growth of the manganese oxide in layers round a nucleus of already-deposited ore. The mixed psilomelane-wad ores of Ramandrug in Sandur are interest- ing because they are often laminated, the lamination being a relic of the parallel structures of the slates or phyllites by the replacement of which they have been formed. Both in these ores and in those of Mysore it seems as if the wad is first formed aud afterwards passes into psilomelane. Another variety of ore, which is not common, except Pisolitic {aluminous) man- 1 Mysore, is oolitic and made up of numerous ganese-o1 es. small rounded bodies, usually composed of psilomelane, and averaging 0°02 to 0:05 of an inchin diameter ; these bodies are set in a soft brownish-black matrix, which gives a chocolate- coloured streak, and to which no definite mineralogical name can be given. Such ore is very high in iron, and a specimen of it, analysed by Mr. C. Fawcitt of Shimoga, showed 33°58 per cent. of manganese peroxide and 44:16 per cent. of ferric oxide, corresponding to 21°23 per cent. Mn and 30°91 per cent. Fe respectively. But the chief interest of this analysis, which is given in full on page 1138, lies in the large percentage of alumina, namely 13-04 per cent. ; here, in fact, we seem to have a case in which the manganese has not been deposited separately from the alumina. These lateritic ores differ greatly in quality from those obtained from. the manganese-ore deposits of the Dharwar facies in the Central Prov- Chemical composition of inces and elsewhere. When the ore consists of the lateritic ores. pyrolusite the composition is fairly definite. corresponding approximately to the formula MnO,. But when the 1 See ‘ pseudomanganite ’ in Part I. Cuap. XIX.] MANGANESE IN LATERITE, 389 ore is a variety of psilomelane its composition may lie anywhere between certain fairly wide limits ; for it seems that a piece of psilomelane may contain as much as 29 per cent. of iron without showing any visible difference from an ore containing only 5 per cent. of iron and a corres- pendingly greater amount of manganese. This leads to a great vari- ability in the composition of the ores despatched, unless they are carefully assayed, and judiciously blended or mixed so as to keep the output up toa certain standard. The average percentage of iron in these ores is considerably higher than in the Central Provinces ores, with a correspondingly lower figure for the manganese. On the other hand, the lateritic ores, as a consequence of their mode of formation, are usually much lower in silica than the Central Provinces ores. The phosphorus also seems to be consistently lower. These features of the lateritic ores are well shown by the following figures, which should be compared with the figures for the Central Provinces and Vizagapatam ores given on pages 510 to 513 :— TABLE 24, Analyses of lateritic ores. Shimoga.2 | | Belgaum.1 | Sandur.! Higher grade | Lower grade | ores, eres, -- Manganese. . | 31:2 —60°8 44 —56 cae eed —54'39 Weegee || OT —18,"4 10) | 10. ~ =20 ee —19°40 | | Siles) =. - | 06 — 2°5 1—3 2 —6 | 0°43 — 1:00 Phosphorus. .| 0°01 —0°12 |0°015 — 0060 0°01 — 0°6 | 0°016— 0°33 a ET 1 From figures supplied by Mr. C. Aubert. 2 From figures supplied by Mr. C. Fawcitt. CHAPTER XxX. GEOLOGY —concluded. Manganese in the Tertiary and Recent Formations. Lateritic gravel or manganese-ore pisolites—Manganese in the Tertiary—In the post-tertiary—In recent deposits—In ponds and rivers—In deep-sea deposits—In manganiferous sands and soils—In fault-rock of various ages. Lateritic Gravel (Manganese-ore Pisolites). In many areas where manganese-ore deposits occur one finds, scat- tered over the surface of the ground, numerous small rounded bodies of very uniform size, namely about that of a lentil or small pea. They are brownish-black in colour and, when fractured, are seen to be black inside and to consist of manganese-ore. These bodies can therefore be designated manganese-ore pisolites. A good example of their occurrence in considerable abundance is to be found at Kurmura in the Bhandara district. Here, on the low ground on the south side of the ore-ridge, they lie scattered in great abundance. When fractured they are found to be of two lands. Some of them are undoubtedly of detrital origin, consisting of rolled fragments of the manganese- ores occurring on the ore-ridge above. Such pisolites are, of course, very variable in character, on account of the variety of manganese-ores from which they have been formed; many of them are seen to be com- posed of the hard grey braunite-psilomelane mixture. The pisolites of the other sort show a concentric structure when broken and are much softer than the generality of the pisolites of detrital origin. Their streak is usually not pure black, as it would be if the material of which they are composed were almost entirely manganese oxide; but a brownish black, probably denoting the presence of a considerable proportion of oxide of iron intimately associated with the manganese oxide. In another mode of occurrence these pisolites are scattered through clay, either thickly or thinly. As before these pisolites are found, when broken open, to be some detrital and some concretion- ary in origin. The clay in which they occur is usually either resting on or not far from a manganese-ore deposit. In the Central Provinces, the Manganese-ore pisolites. Detrital pisolites. Concretionary pisolites. Modes of occurrence. Cuar. XX.] MANGANESE-ORE PISOLITES, 391 ordinary succession, as seen in a section of a deposit being quarried in the alluvium, is an overburden of alluvial clay resting on a detrital accumulation of fragments of manganese-ore mixed with pieces of the accompanying rocks. The fragments in these detrital accumulations vary from very small dimensions up to pieces several inches in diameter, the tendency being for the fragments to increase in size as the ore in situ. is approached. It is these detrital accumulations that are designated in various parts of this memoir as the talus-ore deposits. Sometimes these talus-ore deposits rest directly on the ore-body, but as often as not they are separated from the ore-body by a certain thickness of the pisolitic gravel. Thus at Kandri such an intervening layer of manganese-ore pisolites, about one foot thick, is to be seen in many of the pits in the talus-ore deposits. When the pisolites are broken open they are found, as before, to be some of them of detrital origin and some of concretionary origin. The origin of the detrital fragments in all these different cases is easy Oricin of the detrital to follow. Thus, in the case of Kurmura, the pisolites. rolling of small fragments down the hillside and subsequent movement in every heavy shower of rain over the surface where they now lie is sufficient to account for their present rounded condition. It is easy, moreover, to conceive of such mechanically rounded fragments becoming enclosed in alluvial clay. In the cases in which these pisolites are found between the ore-body and the talus-ore deposits, it is necessary to suppose that first the pisolites collected on the surface of the ground in the same way as they are now found at Kurmura, and that later the talus-ores covered them up. Many of these pisolites, both detrital and concretionary, are also found between the fragments of manganese-ore composing the talus-ore deposits ; as before the origin of the detrital pisolites is easy to understand. The origin of the concretionary pisolites in these different cases Origin of the concretion- 18 not so simple. Briefly stated, however, ary pisolites. it is probable that circulating surface waters dissolved a certain quantity of manganese from the manganese-ore bodies or their detritus and subsequently deposited this manganese wherever the conditions were favourable. All that would be necessary for this process to take place would be for the ground waters to contain either carbon dioxide or organic acids in solution. Such waters, on coming in contact with manganese-ore, would take certain quantities of manganese into solution. This might be deposited in 392 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [ Part II: various ways. If the manganese were held in solution by carbon dioxide as the bicarbonate, and the carbon dioxide should be released, either by the rapid motion of the solvent waters, or by their coming within range of evaporating agencies, as they would at the surface, the manganese would, in the absence of oxidizing influences, be deposited as carbonate, only to be oxidized later; or, if subject to oxidation at the same time as the carbon dioxide was released, it would be deposited directly as oxide. Another way in which the manganese might be removed from solution is by the waters coming m contact with the atmosphere, or with air entangled between the particles of soil and rock a little below the surface. In this case, whether the carbon dioxide were released or not, the manganese salts would probably be oxidized with deposition of manganese in either the sesquioxide or peroxide form; whilst, if the solvent for the manganese were organic acids, the deposition of the manganese might easily take place if the oxidizing influences were stronger than the dissolving tendencies of the organic acids, which, indeed, might themselves be broken up under the same conditions. The manganese carbonate or oxide liberated in one of these ways would by preference deposit itself against already deposited manganese carbonate or oxide, and the tendency would be for this deposition to take place in concentric layers, any carbonate deposited becoming in all probability oxidized almost as soon as depo- sited. The method of deposition is thus easy to understand. The only point requiring elucidation is where did this deposition take place? The answer is supplied by two sections. One of these, seen Sections at Mansar and at Mansar, is figured on page 884, and shows Beldongri. that pisolites of manganese oxide have been formed in the mica-schist along the junction of this rock, both with the manganese-ore im situ, and with the overlying talus deposits. From this it seems certain that these particular pisolites were deposited after the accumulation of these talus deposits and are probably still in process of formation ; especially as the mica-schists, even in the dry weather, are wet, showing that probably the junction of the ore and schist acts as a directing influence for circulating waters. The other case was seen in the Beldongri quarry (see page 910), where mica-schist was again seen to contain numerous scattered pisolites of concretionary origin, the schist being overlain by pisolites set in a ferruginous clay, and this by a pisolitic gravel of which the separate pisolites were apparently mostly of detrital origin. Hence it is probable that a portion of the concretionary pisolites is formed in the mica-schist so often Cuap. XX, ] MANGANESE-ORE PISOLITES. 393 forming the ‘ country’ of a deposit, along narrow zones traversed by circulating surface waters. Inall probability pisolites of concretionary origin are also formed directly in the interstices of the talus-ore accu- mulations and in any porous soils. Thus the mixed accumulations of pisolites must have often been formed by the denudation of the rock, such as mica-schist, in which the concretionary pisolites were formed, with the separation of these pisolites from their matrix, and their subse- quent admixture with pisolites of detrital origin, only those detrital pisolites of approximately the same size as the average size of the con- cretionary pisolites being deposited by water along with the latter. Hence, of the different occurrences of pisolites mentioned above, the ones in clay are in all probability often entirely of derivative origin, both concretionary and detrital pisolites having been washed into the clay. In the pisolitic deposits underlying the talus-ore accumulations the concretionary pisolites may have been in part rolled into the deposits along with the detrital pisolites, at the time of the formation of these deposits, and may have been in part subsequently deposited by manganiferous solutions ‘percolating through these porous deposits. The pisolites, such as those of Kurmura, that are found lying loosely scattered on the surface of the ground, have probably all, even when concretionary in origin, been mechanically carried to their present position; for it does not seem probable that such concretions would form actually on the surface of the ground. Were such an accumulation as that of Kurmura to be now covered up by talus-ores derived from the hill above, we should get an exact parallel to the talus-ore deposits at present being worked ; for the talus accumulations would be separated from the underlying rock by a layer of manganese-ore pisolites, of which a certain number would doubtless get mixed up with the fragments of ore in the talus-ore deposits. Summary of origin. Although all the examples quoted above are in the Central Pro- vinces, yet such pisolitic deposits are equally common in association with the manganese-ore deposits of Vizagapatam and other parts of India, and will probably be found to be of common _ occurrence wherever manganese-ore deposits are found. As an example of abundant pisolites scattered through sandy soil mention may be made of the occurrence at Gudhidri in ue Ganjam district (page 1036). 394 MANGANESE DEPOSITS OF INDIA: GEOLOGY, [Parr II: Manganese in the Tertiary. Excluding the laterite, which probably ranges in age from lower tertiary to recent, manganese-ores have been but sparingly found in the tertiary formations. In the Subathu division of the Siwaliks in Afghanistan there is a record of a black substance that may possibly be manganese-ore, although supposed to be graphite!. An occurrence of manganese-ore, Manganese in the Fossil. possibly in the Fossil-wood group in the wood group. Magwe district of Burma, is mentioned on page 669; whilst a certain occurrence in this formation of masses and nodules of ores of this mineral in the Taung-gnu district is noticed on page 671. This occurrence is of no economic importance. Manganese in the Siwaliks. Manganese in the Post-Tertiary. An occurrence of manganiferous iron-ore in the post-tertiary rocks ef the Hanthawadi district in Lower Burma is noticed on page 669. Recent Deposits of Manganese, General. Under the influence of the various meteoric agencies, such as rain, frost, and heat, the rocks of the earth’s crust are constantly being broken up. Some of the constituents of the rocks pass into solution in the surface and ground waters and are eventually deposited in ponds and lakes, as incrustations on rocks in rivers, possibly as infillings to mineral veins, and also as efflorescences on the surface of the ground. Those portions of the materials taken into solution that are not thus deposited are eventually carried to the sea in the waters of the rivers draining into it. Whilst a certain proportion of the constituents of rocks thus passes into solution and thus is disposed of, a considerable, and probably by far the larger, proportion is transported mechani- cally by water to be deposited in river valleys, lake basins, or the sea. The manganese contained in the various geological formations may be subjected to any of the influences mentioned above. Conse- quently the recent deposits of manganese-ore can be divided into four groups, as follows :— 1. Manganese taken into solution by the meteoric waters and de- posited on the land areas, either in lakes, ponds, or rivers. 2. Manganese that escapes deposition on the land areas and.is car- ried to the sea, where it gets deposited on the ocean bottoms, 1.4. B. Wynne, Re>. G@. 8. 1., XII, p. 111, (1879), Cuap. XX] POND AND RIVER DEPOSITS. 395 3. Manganese that is transported mechanically and deposited on the land areas, such as in lake and river bottoms, as for example in the form of sands. 4. Manganese that is transported mechanically to the sea and there deposited. No case of the last-named sort of recent deposit has yet been recorded within the limits of the Indian Empire. The known recent deposits of manganese-ore in the Indian Empire can thus be divided into three groups :— 1. Deposits in ponds and rivers; and on the surfaces and in the cracks, bedding and joint planes, of rocks, as dendrites. 2. Deep-sea deposits. 3. Manganiferous sands and soils. Deposits in Ponds and Rivers, ete. As has already been mentioned, the rocks of the earth’s crust nearly all contain manganese in smaller or larger proportions. Although the percentage of manganese in most rocks is very small, yet when such rocks are exposed at the surface and subjected to the influences of the weather this small amount of manganese often passes into solution under the solvent action of water containing either organic acids or carbon dioxide. Such water usually finds its way into the drainage system of the country. The tendency is for the manganese to be redeposited at the earliest possible opportunity. The condition for this to take place is usually that the water should be subjected to oxid- izing influences, although it is sometimes deposited under reducing conditions. Rapid motion of the water, as at a waterfall or rapids, will sometimes bring about a deposition of the dissolved manganese as oxide!. A good example of this is to be seen in the fine exposure of Psilomelane deposited at Crystalline limestones that occurs in the Pench a waterfall on the Pench. river at Ghogara in the Nagpur district (see page 961). In one place the river forms a small waterfall down a cleft in the limestone, which consists partly of the brownish black manga- niferous variety and partly of light-coloured varieties. The mangani- ferous limestone is coated with a layer of psilomelane, which has been deposited in concentric layers so as to follow all the curves into which the limestone had been previously carved by the water of the river. 1 For foreign examples of this, on the Orinoco, Congo, and Nile, see G. Bertrand, Revue Générale de Chimie, VIII, pp. 209, 210, (1905). 396 MANGANESE DEPOSITS OF INDIA: GEOLOGY, [Parr II: This layer is usually about half an inch thick, but in places as much as one inch thick. It has’an iron-black polished surface, with in places a sort of mammillated appearance. In some places there are thin layers of radiated pyrolusite in the psilomelane, and the underlying limestone contains quite a quantity of secondary pyrolusite, which is most abundant near the coating of psilomelane. This occurrence probably illustrates the following points :— 1. The waters of the Pench river contain salts of manganese in solution. 2. The dissolved manganese is most easily deposited as oxide where the water containing it comes in rapid contact with the air, namely at the waterfall. 3. This manganese oxide is deposited on the manganiferous lime- stones in preference to the non-manganiferous ones. This psilomelane was undoubtedly deposited comparatively recently ; for it follows all the carvings of the limestone and was therefore deposit- ed after the river carved the limestone to its present shape. It seemed, however, as if the psilomelane was actually being denuded away by the river at the time of my visit ; not, of course, by solution, but by the wearing action of the waters. In a pond near Rambha in Ganjam, I found in January 1905 that the Manganese deposited in a Water on evaporating had left a deposit of pond near Rambha. manganese oxide on the gravelly sides of the pond, each piece of stone being so coated. Another interesting example is a deposit of pyrolusite found on the surface of Bijawar limestone in a nala at a point about three-quarters of a mile S. 8. W. of the camping place in the Dhar Forest known as Pan Kuan. In one place the limestone surface had been corroded and coated with a deposit of frag- ments of pyrolusite cemented by calcareous tufa. Close by was a steeply sloping surface of limestone with a coating of almost pure pyro- lusite, containing in places patches of dark brown crystalline calcite, and showing at the junction with the limestone a gradual passage into it, indicating that the pyrolusite was formed by the replacement of the limestone. When I saw this occurrence the ndl&é was quite dry ; but in the rainy season it must often carry a large quantity of water. This must have taken into solution a portion of the manganese that is so widely distributed in the Lameta rocks of this area; and coming in Pyrolusite at Pan Kuan. z ‘3ZIS TVYUNLYN f *(1LH9DIT) V4NL SNOTYVOTNVO GNV (WYVG) 3LISMIOYAd “VIGNI IVWYLN3O ‘LS3YO4s YWHG ‘NYNY NVd WONG * *JOUeD "MM ‘A *H Aq ‘ojogg "0D aghgzozoyg vjjnI1v7 Std TAXXX ‘9A ‘suowsyy VIGNI 4O AGZALAS TVITIOTODI Cuap, XX.] POND AND RIVER DEPOSITS 397 contact with the limestone must have given up a portion of its mangan- ese in return for a portion of the calcium carbonate of the limestone. The above explanation is given on the supposition that the pyrolusite is of recent formation. This, however, cannot be considered as quite certain in a region where denudation has in so many places just worked its way down to the old land surface of pre-Lameta times. But even if the pyrolusite date back to this pre-Lameta time it will probably have been formed in much the same way—except as regards the source of the manganese—as if, as is almost certain, it has been deposited in recent times (see Plate 15). The foregoing are examples of manganese-ores deposited recently at the surface. There may also be places at small distances Dendrites of manganese beneath the surface at which the conditions are oxides. favourable for the deposition of manganese oxides from percolating waters. Thus dendritic growths of black manganese oxide are often found on the surfaces of joint and bedding planes of rocks when they are uncovered in the course of quarrying or mining operations. As would be expected this phenomenon is parti- _ cularly common in manganese quarries. Thus I have seen beautiful examples at the Mansar mine on the surface of the fine-grained gneiss underlying the ore-body. Equally good examples were seen in the manganese-ore quarry at AsalpéniII or Karli. Here the den- drites were also on the surface of the bedding planes of the underlying rock, a fine-grained schistose quartzite. Such dendrites may also be found on the surface of rocks in almost any formation. Thus very fine examples have been found on the bedding planes of slabs of Vindhyan sandstone quarried at Panna for building purposes. Some fine specimens from this locality are exhibited in the Museum of the Geological Survey of India, the fern-like growths being as much as 22 inches in length (see Plate 4). In sinking wells for the foundations of the new railway bridge across Mice. Gade th the Ganges at Allahabad some fossil mam- pleistocene mammalian malian remains were found embedded in a remains at Allahabad. calcareous conglomerate 80 to 100 feet below low water mark!, On examination it was found that these mam: malian remains were impregnated with oxide of manganese?. This manganese oxide must have been deposited, long after the sealing 1 Ree. Geol. Sur. Ind., XXXII, p. 136, (1905). 2 Ree. Geol. Sur. Ind., XX XIII, p. 157, (1906). 398 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [ Parr II: up of these remains in their concrete matrix, by percolating waters, not necessarily derived from those of the present river, but more probably consisting of ground waters circulating before the Ganges happened to flow in its present channel. In the same way stains of manganese oxide may be found in almost Manvdnsse- as dene en rock near the surface. Thus some speci- in asbestos from Tumkhera mens obtained in opening up an asbestos Khord.- deposit at Tumkhera Khurd in the Bhandara district were brought to the Geological Survey Office and were found to be composed of a mixture of asbestos and talc, with black stains of oxide of manganese in the fissures. Deep-sea Deposits. It is a well-known fact that the rivers draining off the land into the seas and oceans contain a certain amount of manganese salts in solution. The quantity, although a very small proportion of the total salts in solu- tion, isin the aggregate so large that, if the figures given by Sir John Murray be anything like correct, the amount of dissolved manganese salts annually carried into the sea must be equivalent to about 37,000,000 tons of manganese sesquioxide, Mng03, or 26,000,000 tons of metallic man- ganesel. Before discussing the formation of the deep-sea deposits of manga- nese-ore I want to show that it is probable that the whole, and perhaps the larger part, of this manganese has not remained in solution in the sea-water. Murray gives the amount of manganese in river-water as equivalent to 5,703 tons of Mng03 per cubic mile”, and the number of cubic miles of river-water entering the sea every year as 6.5243. Now 10,000,000 years is probably a very conservative estimate of the time during which oceans must have existed, with accompanying land areas from which rivers were draining and supplying water to the ocean to take the place of that removed by evaporation4. The present volume of the water in the oceans and seas of the world is given by Murray as 323,722,150 cubic miles® or, say, approximately 324,000,000 cubic eee Min. Geol. Inst. Ind., I, p. 73, (1906), 2 Scottish Geog. Mag., III, p. 77, (1887). 3 Op. cit., IV, p. 41, (1888). 4 We can neglect the question of the permanence of the oceans; for if they have not had something like their present distribution during the whole of this time, the water occupying formes oceans must have passed from old to new ocean are;s on the formation of the latter. 5 Loc. cit., p. 39. Cuap. XX.! DEEP-SEA DEPOSITS. 399 miles. If we can assume that this represents roughly the average volume of the oceans during the whole of this period of ten million years, and that the average annual amount of river-water flowing into the sea during the same time is 6,500 cubic miles, we see that the whole of the water P : : 324,000,000 of the ocean could have been supplied by the rivers in ST REOO Et 50,000 years approximately. The supply of river-water is of course kept up by the evaporation of sea-water and its precipitation on the land in the form of rain. In this process the dissolved salts are of course left behind in the sea ; hence, as in 10,000,000 years the rivers must have contributed the amount of . 10,000,000 , water in the oceans a nd —=200 times over, sea-water should contain 200 times as much manganese per unit volume of water as average river- water. This means that a cubic mile of sea-water should contain man- ganese equivalent to 5,703 xX 200 = 1,140,600 tons of manganese sesquioxide, supposing that all the manganese that has entered the sea during this 10,000,000 years has remained in solution in the sea-water. Now the figures given by Murray! for the dissolved matter in sea-water in terms of tons per cubic mile are as follows :— Tons per cubic mile. Magnesium carbonate (MgeCO3) - “ : : : 438,000 Calcium carbonate (CaCO3) . ; ; ; : - : 6,147,000 Potassium sulphate (K2S0O4) . : : . : : 2 3,723,000 Sod‘zm chloride (NaCl) : : : : : : - 117,441,000 Magnesium chloride (MgClg) . : ‘ : ‘ : ; 16,419,000 Magnesium sulphate (MgSO) : : : 5 : : 6,529,000 Magnesium bromide (MgBrg) : ‘ : - - : 328,000 ToraL 5 151,025,000 From these figures of Murray it will be seen that haa all the man- ganese remained in solution in sea-water it would have formed 0°7% of the total salts and hence have been quite an important constituent?. It is of course known to be present in sea-water in small amounts ; thus, according to Forchhammer, as summarized by Dittmar3, manganese is readily detected in the residue left on re-dissolving sea-water solids in water. But the quantity is apparently so small that, as far as I know, 1 Op. cit., III, p. 77. 2 Had we considered a period of only 1,000,000 years, the value of the MngQg, 114,060 tons per cubic mile, would still be too small to neglect, namely 0:07°/, of the total sea salts. 3 Challenger Reports, Physics and Chemistry, Vol. I, p. 2, (1884). 400 MANGANESE DEPOSITS OF INDIA: GEOLOGY. [Parr, II: it has never been determined ; chemists seem to have considered it unne- cessary to take it into account, even in analyses carried to six figures! The question then arises as to what has become of that portion of the manganese that should be present in the sea-water, and is not. The obvious answer is that it must have given rise to at least a portion of the manganese-ores known to occur at the bottom of the sea. For, during deep-sea exploration work, nodules of manganese-ore are frequently dredged up from the sea floor. In fact, in some places, according to Murray, the sea bottom and everything on it is coated with manganese oxide—shark’s teeth, shells, corals, sponges, and other remains, both organic and inorganic, being encrusted with this substance. The way in which the manganese is deposited, and also its source, is a matter of some doubt, and for a full discussion of this subject the reader may be referred to the excellent work of R. A. F. Penrose, Jr.?, and to the Challenger Reports, Volume on Deep-sea Deposits, pp. 372-8, (1891), by John Murray and A. F. Renard. The various views held on each of these points can be seen from the following list? of the opinions of different authorities as to the mode of origin of manganese nodules :— «1. The manganese of the nodules is chiefly derived from the decomposition of the more basic volcanic rocks and minerals with which the nodules are nearly always associated in deep-sea deposits. The manganese and iron of these rocks and minerals are at first transformed into carbonates, and subsequently into oxides, which, on depositing from solution in the watery ooze, take a concre- tionary form around various kinds of nuclei (Murray)s. 2. They are formed under the reducing influence of organic matters on the sulphates of sea-water, sulphides being produced and subsequently oxidised (Buchanan). 3. They arise from the precipitation of manganese contained in the waters of submarine springs at the bottom of the ocean (Giimbel). 4. They are formed from the compounds of manganese dissolved in sea- water in the form of bicarbonates, and transformed at the surface of the sea’ into oxides, which are precipitated in a permanent form on the bottom of the ocean (Boussingault, Dieulafait)’. Penrose further considers the possibilities that marine plants suchas sea-weeds may segregate manganese in their tissues, this being deposited 1 Thorpe’s Inorganic Chemistry, I, p. 208, (1902). An. Rep. Geol. Surv. Arkansas for 1890, Vol. I, pp. 559-569. 3 Taken from the above-mentioned volume of the Chall. Rep., p. 373. 4 In a footnote at this point Renard says:— ‘While admitting ‘hat a part of the manganese accumulated at the bottom of the ocean may be derived from the decomposition of voleanic rocks, in the manner described above (No. 1), it appears to me that the greater part must have been derived from the manganese in solution in the sea-water ’, is] CHap. XX. ] DEEP-SEA DEPOSITS. 401 on the death of the plant ; and also that the precipitation may have been brought about by the action of calcareous sediments, when on the sea floor, or when passing through the water on the way to the bottom, the process being one of substitution by which calcium carbonate passes into solution with the precipitation of a corresponding amount of manga- nese oxide. He does not, however, regard either of these, or any other theories that have been advanced, as adequately explaining the formation of these submarine manganese-ores. I do not intend to discuss here the various theories outlined above ; but I will give what seems to me a fairly satisfactory explanation, for the consideration of those who have had practical acquaintance with deep-sea deposits of manganese-ores. Now according to the researches of Dittmar!, the waters of the ocean contain both dissolved oxygen and carbon dioxide. Even at the greatest depths there is a small quantity of oxygen in solution”, though the amount is much smaller than in the surface layers. Dittmar takes the presence of this small amount of oxy- gen in the depths of the ocean as a proof that the water is not absolutely stagnant3, but subject to a slow circulation. The amount of carbon dioxide in sea-water seems to be greater than that of the oxygen; but it is usually less than is required to keep all the carbonate of calcium present in sea-water in the form of bicarbonatet+. Now calcareous sediments are of frequent occurrence on the sea-bottom, and in such cases it may be supposed that the manganese-ores contained in the sediment have at least in part been formed by the replacement method considered by Penrose. But it must be remembered that a large proportion of the sea-bottom is covered with red clay containing abundance of manganese-ores, both in the form of concretions and as incrustations on the remains of marine organisms. A certain proportion of the manganese-ore in these red clays may have been formed by the replacement by calcareous matter of the manganese salts contained in the adjacent water; for these red clays do contain a certain amount of calcareous matter, this being in the form of such corals and thick shells as either live at, or have been able to reach, the great depths at which these red clays are found, without suffering the fate of the thinner- shelled organisms of being dissolved on the way down. But the amount 1 Challenger Reports, Physics and Chemistry, I, (1884). 2 Loe. cit., p. 226. 3 Loc. cit., p. 225. * Loc. cit., p. 220. TI M 402 MANGANESE DEPOSITS OF INDIA: GEOLOGY, { Part Il: of calcareous matter thus available does not seem to be adequate to account for the deposition of all the manganese-ore; although it must be remembered that the greater the amount of replacement of calcareous matter that has taken place, the smaller will be the amount of this material now left to be dredged up. The paucity of calcareous matter in these red clays, however, is probably due not to its having been nearly all used upin precipitating manganese oxide, but to the solution on their way to the bottom of the thin-shelled or calcareous organisms that in places where the ocean is less deep give rise to calcare- ous oozes. Now considering the fact that there is as a rule no excess of carbon dioxide in sea-water over that required to hold all the calcium carbonate in solution in the form of bicarbonate, it seems probable that when this solution of calcium carbonate takes place corresponding amounts of oxides of manganese and iron are thrown out of solution, according, in the case of manganese, to the following equation :— MnHo2(CO3)2 + 2CaCO3 + 2H20 + O = 2CaHo(CO3)2 + HeMnOsz. Any such precipitated particles of hydrated peroxide of manganese and iron would gradually sink to the bottom, which they would probably reach without solution owing to the absence of free carbon dioxide; even if they suffered solution before reaching the bottom their precipitation would lead to the transference of a portion of the manganese to a lower stratum of the sea, and, if larger calcareous organisms passing this point did not bring about another precipitation of this dissolved manganese and iron, the slow circulation of the sea-water would finally bring it within reach of the sea-bottom. The falling particles, on reaching the bottom, would act as nuclei round which further portions of manganese oxide would be deposited by concretionary action ; whilst if no particles actually reached the bottom in this way, but only water with manganese in solu. tion, then the oxygen dissolved in the water would lead to the deposition of the dissolved manganese round any already-deposited portions of manganese oxide, and round other nuclei. I have given the foregoing brief outline of a possible way in which these deep-sea deposits may have been formed, and are still forming, to show that it is not necessary to suppose that all the manganese, or even the larger portion of it, has been derived from volcanic rocks or cosmic dust, as some previous writers have imagined. It has, moreover, the advantage of accounting for the disappearance of the large amounts of manganese salts that are constantly being carried “CHap. XX. j DEEP-SEA DEPOSITS. 403 ito the sea by rivers. My ideas as to the origin of the manganese Summary of origin of and its method of precipitation can be summed deep-sea nodules. up as follows :— 1. The manganese, although probably partly derived from cosmic dust and volcanic débris, has been mostly precipitated from solution in the sea-water, the manganese salts having been originally brought into the sea by rivers. 2. The manganese oxide, although possibly partly precipitated as a result of the action of the vital processes of organisms, both vegetable and animal, has been mainly precipitated by cal- cium carbonate aided by the obscure process of segregation from solution round a nucleus!. 3. Where the sea-bottom consists largely of calcareous sediments, the precipitation may have been mainly brought about by the solution of some of this calcium carbonate with the deposition of an equivalent amount of manganese oxide owing to the presence of free oxygen. 4. Where the sea-bottom consists of red clay, it does so because the depths are there so great that the tests of thin-shelled organ- isms are completely dissolved by the sea-water before they reach the bottom. The calcareous matter in being dissolved deposits an equivalent amount of manganese oxide, which descends to the bottom, and there acts as a nucleus for the segregative extraction of manganese from the waters at the sea-bottom. The deposition of manganese oxide by means of calcium carbonate associated with the red clays probably also occurs to asubordinate extent, for the shells of thick-shelled organisms may reach the bottom before being entirely dis- solved. There is at least one record of the occurrence of nodules of manganese- Detesee! ieduies OTe in Indian waters. This is the one, noticed on from the Maldive page 1116, in the channels between the composite Islands. atolls in the Maldive Islands. The depths given for -soundings in such channels range from 100 to 769 fathoms, so that this occurrence can hardly be regarded as a deep-sea one. 1 Probably to be explained as due to the supersaturation of the solution as regards >the substances being deposited, here oxides of manganese and iron. 404 MANGANESE DEPOSITS OF INDIA: GEOLOGY. | Part II: Manganiferous Sands and Soils. It might be expected shat in areas where manganese-ore deposits exist, the sands and other mecnanical detritus of the streams draining therefrom would often contain particles of manganese-ore. I have occasionally noticed small particles of manganese-ore in the sands of the Indian rivers, but have never specially looked for manganiferous sands. Nevertheless, it may be considered as fairly certain that such sands exist. And a black sand should not always be taken to be an iron sand, but should be tested for manganese ; for if it contained this element in considerable proportion it could be taken as a good prospecting indication of the proximity of a manganese-ore deposit. The old observers, however, seem to have noticed such sands. Thus there are records of ‘iron and steel sands with manganese’ in the Nizim’s dominions (page 989), of ‘ black sand’ containing manganese in the Coimbatore district (page 1032), and of ‘jet black sand containing iron and manganese ’ in the Nellore district (page 1040). Soils may also be highly manganiferous owing to the pre- sence of numerous particles of manganese oxide scattered through the other material composing the soil. These may have found their way into the soil mechanically, or may have been deposited in it by percolating water; but in the latter case the fact that the manganese oxide had been deposited from solution would probably be easily detected by noticing that it tended to form segregations. A good example of manganiferous soil has been found in the Chitaldrug district of Mysore (see page 1125), where extensive areas are said to be covered toa depth of 2 to 3 feet witha dark manganiferous earth yielding on analysis 9 per cent. manganese. My attention was also called to some very manganiferous black soil near Kumsi in the Shimoga district of Mysore. Manganese in Fault-rock of Various Ages. In the outlying portion of the Dhar State known as the Dhar Forest or Manganese-ore in Nimanpur, situated on the north bank of the Narbada Lee 5 ao See river, and in the adjoining portions of the State of Provinces. Indore lying to the west, as well as in the neighbour. ing parts of the district of Nimdr lying on the south side of the same river, the rocks of the BijA4war system are traversed by dyke-like bands of a breccia composed of angular fragments of quartz, quartzite, chert, and hornstone, set in a hornstone-like siliceous matrix. These rocks are usually known as hornstone-breccia or chert-breccia. Not only do they traverse~ Cuap. XX, ] MANGANESE IN FAULT-ROCK. 405. rocks of Bijawar age, but also rocks of Vindhyan age, in which case they also contain fragments of Vindhyan sandstone. The age of these dykes must therefore be post-Vindhyan ; and Mr. E. Vredenburg, who has made a careful study of these breccia dykes, is inclined to regard them as of Gondwana age and as having been formed at the time of great tectonic disturbance by which the Gondwana basins were faulted. In many cases the matrix of these dykes has been replaced by black manganese oxide, the result being a rock composed of the angular fragments of the breccia, usually quartz, set in a black matrix of manganese oxide. The time at which this replacement of the matrix of the breccia by manganese oxide took place is, of course, not known ; but if the time of the formation of the breccias be really the end of the Gondwana period, then this replacement is probably post-Gondwana and _pre- Lameta. I will not give here an account of particular occurrences. These will be found under the headings of the respective areas. C. A. Hacket has found veins of manganese oxide in /ault-rock near Manganese-ore in Datunda in Bundi State. The age of this fault- fault-rock, BundiState. rock is, of course, not known. But if it belong to the great boundary fault separating the Aravallis and Upper Vindhyans in this part of India, then it is post-Vindhyan in age. CALCUTTA SUPERINTENDENT GOVERNMENT PRINTING, INDIA 8, HASTINGS STREET RVEY OF INDIA. iol, Wetman: COE CREO E TS URVEE : Memoirs, Vol. XXXVII,Pt. 2, Pl. 16 Kalas yl — MAP OF THE CHIEF OCCURRENCES of MANGANESE-ORE IN INDIA. 100 Miles INDEX TO NUMBERS. (Manganese-ore deposits of proved economic value are found in the Districts and States underlined.) PaLar “nial | 8) \ m) : { k i a We j a enapusra onda Yodiay Tao Veber { CHAAR | Sang Sang Giado Te mt dc Bl | 5 1 ham To | Mi ifs aye ank ( BrEnGaL 1. Kalahandi 2. Singhbhum Bomnay 3. Belgawm and North Kanara 4. Bijapur 5. Dharwar (Sangli State) 6. Ndrukot and Panch Mahals 7. Sdtdra all Burma 8. Mergui Centrat Inpia 9. Dhar and Indore 10. Gwalior 11. Jhabua Ganeal PROVINCKS Ke ic. 12. Baldghit ( ata Ay) ; Se 13. Bhandéra te (iz \ | 14. Chhindwara f ir, 15. Hoshangabad re saith OPT UG wn Vs elon Zs y 16. Jabalpur Baa) thal eect * z : Sr i: Néapur eee a : eT : 18. Wun Deancel L = North Seniipist \\ ftvrt Blair c a ir Fintan 1 : j Zo Harparabad cendive 2 RS Sa a ae i pee SL = | Diweae 19. Bidar Telands Mapnas seabhas £5 sadhaté Bar : | i Sam Niosiaie : + ; lee aT : 20. Bellary (Sandur Hills) ’ ee taco mental 21. Ganjam Z iY 5 ne | 22. Vizagapatam GE Farant 2 Mysore SSS 23. Chitaldrug 24. Shimoga sy Minions f Heawands' {holo Awa - Fillasturmati Atot counny uniler Leitials adnviniatretion, Tinks Tint, Moleotm| Atoll —\ Miladamads Atoll Yellow REFERENCE a : Maldive Islauds n wf Georges under Hvitish: control Hurnt Sienna, North Maloomatin Atoll: PIASre Teles g = amend Pe Penang ©) Radidiphote Ato, Lught Blue Green. Vorabusyh Atoll & Renter — The numecata denote He he ye acu level in: feet Coral Bare Tike Mays vx inte dy to it the prxnespul places oO " Hog I Niet reverw: Wea Tilo CST aly 9\G° Litho, 8 I O, Calcutta No 231, Geol Survey of India — July 06 —800. Published under the direction of Coloncl H R-Thuillier, © 1 EB. RE, Surveyor General of India a - Reg NE 383~S Additiona te 1904 ‘ September, 1394. MEMOIRS OF THE GEOLOGICAL SURVEY OF INDIA. Se an | aa aoe - We a a _ = . i yi 4 a) es MEMOIRS OF THE GEOLOGICAL SURVEY OF INDIA. VOLUME XXXVII. THe Maneanese-Ore Deposits or Innis, dy L. Leicn Fermor, A.R.S.M., B.Sc. (London), F.G.S., Assistant Superintendent, Geological Survey of India. Part III: Economtcs anp MINING. Published by order of the Goverament of India. CALCUTTA : SOLD AT THE OFFICE OF THE GEOLOGICAL SURVEY, 27, CHOWRINGHEE ROAD, LONDON : MESSRS. KEGAN PAUL, TRENCH, TRUBNER & CO. BERLIN : MESSRS. FRIEDLANDER UND SOHN. 1909. » Nh ere THE MANGANESE-ORE DEPOSITS OF INDIA. PART III ECONOMICS AND MINING, LEIS ABRIDGED CONTENTS OF PART III, PAGE CHAPTER XXI. History of the Indian Manganese Industry . . 411 XXII. Statistics of Production of Manganese-ore in India . 431 > XXIII. Labour and Costs of Production . A . . 467 s- XXIV. Valuation and Chemical Composition of Menganese- ores i ; 5 : 5 . 404 ~ XXV. Value of the Indian Manganese-ore Production . 529 5 XXVI. Miring or Quarrying of Manganese-ores . : . 544 XXVII. Ditto ditto Cont ound - XXVIII. Uses of Manganese ' A 4 F F . 581 APPENDIX to Parts J, II and III THE MANGANESE-ORE DEPOSITS OF INDIA PART Ill ECONOMICS AND MINING CHAPTER XX], ECONOMICS & MINING History of the Indian Manganese Industry. The working of manganese-ores by the natives of India—Vernacular names for manganese-ore. The fluctuations in the price of manganese-ore. History of the modern manganese industry in India—Madras—Central Provinces —Central India—Bengal—Bombay—Mysore. Although, as far as I am aware, there are no ancient records on BReretiing "of manpe: the subject, it seems probable that nese-ores by the natives of the existence of manganese-ores in India as has been recognized by the natives of the country from time immemorial. They probably regarded them as a sort of iron-ore and made some use of them both in iron- smelting, and for colouring glasses and ename!s, as well as occasionally confounding them with swrma or antimony sulphide, then using them for colouring the eye-brows black. Thus, as noted on page 595, I found, when at Mahabaleshwar in the Western Ghats, that the Dhavads or local iron-smelters had a separate word—waral—for manganese-ore ; they said they used to put a certain amount of it into the charge when smelting iron. Further, an anonymous writer! states that there is a tradition amongst these Dhadvads that the Phoenicians used to carry away manganese-ore. The use at the present day of manganiferous iron- ( 1The Indo-European Commercial Intelligence and Trade Register, TaD de 1907) Wz A 2 412 MANGANESE DEPOSITS OF INDIA: Economics. [Parr IIT: ores and manganese-ores at Ghogra in the Jaba'pur district in the production of a steely iron known as kheri is noticed on page 595, and of the ores of Gosalpur in the same district by local glass-blowers on page 600. Uses of this sort have doubtless given rise to the several names that the ores of this mineral are at one time or another said to have possessed among the inha- bitants of various parts. The following is a: Veraacular names for manganese-ore. list -— TABLE 25. List of vernacular names for manganese-ore. a Locality or : woe : Tanpucee Authority. Kolsa-ka-patthar : i : . | Dharwar. Newbold.1 Ingani, Injani, Injni . : ; . | Punjab. Powell.2 Jugni : 3 : ; F =| 53 cs Nijni " A ‘ : ; 35 ts Missi siyéh : : 2 ; S| of, e Tddali kallu ‘ : : : . | Kanarese. Balfour. Ukkina kallu ‘ ; , : . | Sandur. Fermor. Sudda . : : : . . | Vizagapatam. Carmichael.4 Surma - - : - : + | “ Crozier.5 Waral : ‘ : : ‘ . | Mahabaleshwar. Fermor. * When Newbold visited the manganese-ore deposit of Chik-Vadvati in the Kappatgudda range in Sangli State, somewhere about 18406, he went in the expectation of finding coal; for the inhabitants said there was kolsd-kd-patthar, or ‘ charcoal-stone,’ at this place. Instead he found manganese-ore. He says :— ‘The guides pointed out some partially obliterated excavations which the old inhabitants of the village stated to me had been made by the agents of Hyder & Tippoo.’ He suggests that the report of the existence of ‘charcoal-stone ’ must have led the agents of these Mysorean princes to this spot, doubt- less with as much disappointment as in hisown case. Hence the term 1 Jour. Roy. As. Soc., VII, p. 212, (1848). 2*Punjab Products’, I, pp. 25, 100, 113, (1868). 3 Cyclopedia of India, II, p. 845, 3rd edition, (1885). 4 Vizagapatam District Manual, p. 155, (1869). 5 * On the iron ores, etc., of the Madras Presidency’, Madras, (1855), pp. 239, 240. 6 Jour. Roy. As. Soc,, VII, pp. 212—214, (1842). Cuap. XXI.] VERNACULAR NAMES. 413 kolsd-kd-patthar as applied to manganese-ore is a misnomer. Most o! the Punjab terms are evidently variants of one word, and together with miss¢ siydh are the names under which the mineral is sold in the Lahore bazar; the ore so sold being the peroxide. Missi is the Hindustani word for a certain powder used for colouring the teeth ; and the addition of the adjective siydéh in the case of peroxide of manganese refers of course to the black colour of this substance, in contradistinction to the ordinary greyish brown of miss?. The use of manganese peroxide for the eyes is indicated by the application to it of the term surma, The true surma, however, is antimony sulphide, and the merchants in the Vizagapatam district who applied this term to manganese-ore said that the latter was an inferior kind. Another example of the use of the word swrma in this sense is seen in the Central Provinces Gazetteer !, where C. Grant refers to the occurrence of large quantities of ‘ surma (sulphide of antimony)’ a few mi'es to the east of Burha (the old name for Balaghat town). As no antimony sulphide has yet been found in the Balaghat district, it is to be assumed that this passage refers to the large deposit of manganese-ore situated some 3 miles north-east of Balaghat town. The term sudda 2 is perhaps the Telugu form of ‘surma’; whilst 2ddali kallu, meaning charcoal. stone, may be regarded as the Kanarese form of ‘ kols4-kd-patthar ’, and like it a misnomer. In the Sandur Hills I found that some of the inhabitants distinguished between kabbane kallu (iron stone) and ukkine kallu (steel stone), applying the latter to manganese-ore. The use of the term waral by the Dhavads of Mahabaleshwar has already been mentioned. From the foregoing, especially the number of vernacu'ar names, it will be seen that ores of manganese must long have been known to, and worked by, the natives of India. But for whatever purpose worked, the total amount of ore extracted at any one place can never have been very large. Before considering the history of the discovery and working of this Pieisq of the. fluctua, mineral! in India by Huropeans, it will be tions in the price of man- convenient to notice briefly the fluctua- See tions in the price of manganese-ore since 1 1870, page 18. 2 Mr, R. Morris, Collector of the Kistna district, tells me that sudda is more correctly written suddha, and is a Telugu word taken from the Sanskrit; it is used to designate a white pipe clay used for painting walls and also for caste marks. It is a distinct word to swrma and hence its use to describe manganese-ore must be a mistake, 414 MANGANESE DEPOSITS OF INDIA: EcoNomics. [Part III: about 1845. Until this date manganese-ore was chiefly used as a deco- lourizer in glass-making and for the manufacture of bleaching powder. The chief sources of supply to English glass houses and chemical works were Tavistock in Devon and Launceston in Cornwall, with some ore from the Harz in Germany, and Piedmont in Italy. Prices then ruled high. Then the discovery of manganese-ore deposits in Germany caused the English mines to close. After the cessation of mining in Great Britain the price rose to £8 a tonagain for an ore with70 per cent. of peroxide. The discovery of extensive deposits in Spain then again reduced the price, till in 1865 it was only £3 for ore containing 70 per cent. peroxide, and all but three of the British and German mines were closed. The Spanish ores, being pockety, became exhausted, whilst there was a reduced supply from Germany; and at the same time a demand for manganese for steel-making sprang up, due to the start of the manufacture of ferro-manganese in 1865. As the mines then working could not supply the increased demand, manganese deposits were searched for all over the world, whilst the price of man- ganese-ore again went up. With the increased demand new deposits were found, but new economies also introduced. Thus whilst formerly manganese-ore was used but once in the manufacture of chlorine, it is now recovered with a loss possibly not exceeding 10 per cent. Hence, notwithstanding the increased demand, the above cause and the increased production caused a gradual fall in price to about £3-10-0 in 1881 for 70 per cent. (peroxide) ore, with 2s. 6d. per additional unit, and £3-5-0 in 1886 with 2s. 3d. per additional unit. The price of manganese- ore delivered at the works of Carnegie Bros. & Co,, Ltd., at Bessemer, near Pittsburgh, Pennsylvania, United States of America, which prac- tically ruled the United States market was as follows in 1886 :— TABLE 26. Price of manganese-ore per long ton in 1886. Percentage of Mn. Tron per unit. Manganese per unit. Below 44 10 cents 22 cents 44—47 Ls De 47—50 LI Ys 24 50—53 Me 5 2555 Above 53 ohh ee 26) Cuap. XXI.] PRICES. 415 The foregoing rates are for ore with 0:17 to 0:18 per cent. phosphorus. With 0°14 to 0:17 per cent, phosphorus the price was 1 cent per unit of manganese higher; and below 0:14 per cent. phosphorus 2 cents per unit of manganese higher, With 0:18 to 0-20 per cent. phosphorus the price per unit of manganese was | cent lower than the foregoing prices. The analyses were made on a sample dried at 212° F., and the mois. ture in the sample deducted from weights. The foregoing information is taken from the section on manganese by J. D. Weeks in the Mineral Resources of the United States for 1886, page 208. It will be seen from this that in 1886 ore containing 50 per cent. manganese and only 0:10 per cent. phosphorus would have fetched 27 cents or 135 pence per unit. In the following table and dagram (fig. 23) are given the quota- tions—ifrom the Mining Journal, London—for the price per unit of manganese, for the first week in January and July of each year since 1890, for the three grades into which manganese-ores are usually divided :— TABLE 27. Variation in the price of manganese-ore c.i.f. at United Kingdom ports. First-GRADE SECOND-GRADE | THIRD-GRADE ORE. ORE. ORE. Date. 50 per cent. Mn. | 47—50 percent. | 40—47 per cent. and upwards. Mn. Mn, Pence per unit. Pence per unit. | Pence per unit. January 1890 : . : 18—20 16—17 14—15 July 1890. : ° : 16—18 14—15 | 12—13 January1891 . . . i) i ae ia es July 1891, oa 2 ' 15—16 | 12—15 | 10—12 January 1892 - eis 14—16 12—14 9—12 July 1892. 5 5 > t43—15 | 1le4—14 | 9—12 January 1893 . * c 143—15 | 133—14 9—1" July 1893. 5 : . 14—14} | 11—13 | 9—11 January 1894 . wl, hig 12 in | S10 July 1894. 3 : ; 103—113_ | 93—104 | 8—10 January 1895 : . : 103—113 9—10 8—9 July 1895 . 5 . 10—11 9—10 74—9 January 1896 : C ' . I1—13 ; 1O—12 | 9—11 July 1896. = “ . l1—13 10—12 | 9—l1 416 TABLE 27—contd. MANGANESE DEPOSITS OF INDIA: ECONoMIcS. [Part IIT: Variation in the price of manganese-ore c.i.f. at United Kingdom ports—contd Date. Eee January 1897 FIRST-GRADE ORE. 50 per cent. Mn. and upwards. July 1897 January 1898 duly 1898 January 1899 July 1899 January 1900 July 1900 January 1901 July 1901 January 1902 July 1902 January 1903 July 1903 January 1904 July 1904 January 1905 July 1905 January 1906 July 1906 January 1907 July 1907 — January 1908 July 1908 SECOND-GRADE | ORE. 47—50 per cent. | Min. Pence per unit. THRIRD-GRADE ORE. 40—47 per cent. Mn. ————$—— renee 417 PRICES. Cuap. XX1.j 536 68 | — =} | 1890 1900 ‘0681 Sours sz10d WopsuLy poy 4e o1o-osourSuvu Jo soold oY} UI UONeTIeA 04} SuIMOYS WeIsIC —"e% “BLT he a0 aM 418 MANGANESE DEPOSITS OF INDIA: Economics. [Part IIT: Considering only first-grade ore, it will be seen that at the beginning of 1890 the mean price was 19 pence per unit, and that from this time there was a gradual decrease to a minimum of 103 pence in July 1895. The price then rose to 12} pence in January 1897 ; sank to 104 in 1898 ; rose to another maximum, of 143 pence, in July 1900; sank to 10 pence in 1902; rose slightly to 101 pence, in 1903; and then, at the end of 1904, declined to a minimum of 8} pence, the lowest point reached during the whole of the period from 1890 to 1907. Then came a con- tinuous rise to a maximum of 15} pence at the end of 1906 and beginning of 1907. During 1907 the quotations have fluctuated between 153 and 14} pence, up till the beginning of September, when the prices be- gan to fall, until by February the price for first-grade ere had sunk to 10 pence, and by August, 1908, te 9 pence. The details of the vari- ations since the last minimum, December 3, 1904, are shown in the following diagram :— 419 PRICES. Cuap. XXI.] eyriai er id ey “SET ~- ~~ +++ + = =~ --1907--=*-- "FOBT O4WIa00q cours Sjzod WopSury poyuA 4v e10-asouvZurM fo soofid oy} UT WONCAeA oT} SarMoys MeIseiq—' pZ “BLT 420 MANGANESE DEPOSITS OF INDIA: ECoNoMics. [Parr III: History of the Modern Manganese Industry in India. We can now deal with the modern history of the discovery and working of manganese-ore in India. The first definite record of the occurrence of manganese-ores in India seems to be the account given by Captain F. Jenkins ! in 1829 of the ores found in crystalline limestone in the Pench river, and to the north of Kumari. Both these localities are in the Nagpur district, Central Provinces, the latter being doubtless the Junawani ore-band. In the ensuing years many fresh discoveries were made in various parts of India, and the knowledge so obtained up to 1881 is summarized in Ball’s Economic Geology ; whilst the Mineralogy of the deposits is discussed in Mallet’s Mineralogy, issued in 1887. The first attempt by a European to work any of the Indian deposits was made by Mr. C. W. McMinn, when Deputy Commissioner of Jabalpur, Central Provinces, In 1884 he sank a number of pits at Gosalpur in the Jabalpur district in order to ascertain the extent of the deposits of this locality. After the careful prospecting of the deposits of this area by Mr. P. N. Bose, then of the Geological Survey, however, the matter was dropped 2. This practically carries us to the end of the eighties. With the advent of the nineties the period of mere prospecting of the Indian manganese-ore deposits may be said to have ended, and the manganese industry proper, in which mining has been com- bined with further prospecting, to have commenced. In the following account of the development of this industry the subject is treated by provinces, in the order in which work commenced in each province. In reading this account comparison should be made with the figures and curves of prices given in the preceding portion of this chapter, so as to notice the effect of prices on this development. Madras. The existence of manganese-ores in the Vizagapatam district of Vizagapatam : Madras- was known as long ago as 18523; ee G. Turner and the hut it was not till 1891 that Mr. H. G. Turner, izianagram Mining Co., : ae Limited. previously Collector of this district, formed a syndicate to work the deposits now known as the Kodur mines, The 1 Asiatic Researches, XVII, pp. 207, 208, 210, (1833); abstract in Gleanings in Seience, I, pp. 226, 227, (1829). 2 Rec. G. §. I., XXI, p. 71, (1888); also op. cit., XXII, p. 216, (1889) 8 A. J. Scott, Hdin. New Phi. Jour., LIII, pp. 278, 279. Cuar. XXI.] HISTORY: MADRAS. 421 original discovery was made, according to Mr. Turner !, by noticing that railway contractors were breaking up the blocks of manganese- ore for ballast. The first export was of 674 tons in 1892, although this has not been recorded in the mineral statistics. In 1895 the syn- dicate was converted into the Vizianagram Mining Company, Ltd., with a capital of £30,600, and Messrs. Arbuthnot and Company of Madras as agents. About this time also the Garbhdm deposit 2, the largest yet found in the district, was discovered, and from an output of 15,816 tons in 1895 the output of the district jumped to 56,869 in 1896, and then rose to a maximum of 92,458 tons in 1900. This corre- sponded with the maximum of price. Then, pari passu with the price, the output decreased to 53,699 tons in 1904, and from 63,679 tons in 1905 leapt up to 104,600 tons in 1906. This last increase was largely due to the fact that the sudden increase of prices during 1906 allowed of the export of ferruginous manganese-ores (manganiferous iron-oreg), of which 39,186 tons, containing less than about 40 per cent. manganese, are included in the total for this year given above. The present Manager of the Vizianagram Mining Company’s mines is Mr, Tom Caplen. The success of the Vizianagram Mining Company naturally brought Gordon, Woodroffe & Others into the field. In 1898 Messrs. Co., Kovocri Basivireddy, Gordon, Woodroffe and Company and Kovoori ae Basivireddy, both of Coconada, jointly acquired various deposits in this district and extracted a certain amount of ore. After about 2 years, however, they were compelled to stop work on account of law suits with the Vizianagram Samasthanam. Messrs. A. S. N. & Co. (A. Subha Naidu), mica-mine owners of Indu- kurpet, Nellore, also secured some deposits—at Sivaram and other places—and worked them for one year during 1900 to 1901, and again in 1906, up till when, however, no ore had been exported. During 1905 and 1906, the Madras Manganese Company, with Mr. S. Crawshaw of Vizianagram as manager, started work on several The Madras Mangan. 4ePposits situated within reach of Chipurupalli and ese Company and Bohbili Garividistations. Some of these, such as Garividi, Mining Co., Ltd. Devada, and Garbham, must be extensions of the deposits of the same name worked by the Vizianagram Mining Company. Others, such as Gadabavalsa and Lakshmipuram, are new discoveries. During 1906, fifteen deposits were worked, with an output of 4,366 tons 1 Jour. Iron Steel Inst., No. II for 1396, p- 156. 2 [bid., p. 157. 422 MANGANESE DEPOSITS OF INDIA: ECoNoMIcs. [Part III: of ore ; and during 1907, 36 deposits, with an output of 21,878 tons. On the 1st January, 1908, the properties were transferred to a new company, the Bobbili Mining Co., Ltd., registered in Madras. The capital is Rs, 10,00,000 in shares of Rs, 100 each. Of this about Rs, 6,00,000 were allotted fully paid up to vendors. The managing agents are Messrs. W. A. Beardsell & Co, of Madras. The existence of manganese-ores in the Sandur Hills, forming the Sandur State. Messrs, State of Sandur in the Bellary district of Mad- A. Ghose and Jambonand ras, was recorded as long ago as 1839 by New- Cie., and the General : Sandur Mining Company, bold!; a few of the occurrences were noticed Limited. by Mr. R. Bruce Foote, in his report on the geology of the Bellary district, published in 1895 2. It was not, how- ever, till 1905 that any attempt was made to ascertain the true value of the deposits, and open them up. In this year Mr. A. Ghose visited these hills on behalf of Messrs. Jambon and Cie, of Calcutta, and started to open up the Ramandrug deposit in the same year 3. During the next two years he discovered and mapped a large number of deposits, finding some of them to be of large size. During 1905 and 1906, 1,200 and 3,208 tons of ore, respectively, were shipped, the quantity being small owing to transport difficulties. At the end of 1906 Sir Vincent Caillard joined Mr, Jambon, and in the middle of 1907 the business was con- verted into a company entitled The General Sandur Mining Company, Limited, with a capital of £320,000 ; this company has secured the monopoly of the manganese- and iron-ores of this State for 25 years (see page 99). The Central Provinces. Up till 1899, Vizagapatam was the only district in India producing manganese-ore. In this year, however, Mr. W. H. Clark, and in 1900, Mr. Harvey Dodd, both of the Vizianagram Mining Company, Limited, prospected in the Nagpur district, following up the references given in Ball’s Economic Geology. To the already-known deposits of Mansar and Kodegaon they W. H. Clark, H. Dodd, added Gumgdon, Ramdongri, Kandri, Beldongri, and the Central Provin- §4tak, and Lohdongri. The Central Provin- ces Prospecting Syndicate ; d (Nagpur, Balaghét, and ces Prospecting Syndicate was formed to work Bhandara). these deposits, the members of the Syndicate being Messrs. J. H. Glass, P. Macfayden, and H. G. Turner, with Mr. Clark 1 Mad. Jour. Lit. Sci., X., p. 125, (1839) ; XI., p. 46, (1840). 2 Mem. G.S.I., XXV, pp. 98, 100, 125, 194, 195. 3 Date of first prospecting license—15th March, 1905. Cnar. XXI.] HISTORY : CENTRAL PROVINCES. 423 as manager in India ; the first prospecting license was applied for on 21st September 1899. Work was started on the Mansar deposit towards the end of 1899, and the first shipment took place in the spring of 1900,when the price of manganese-ore was 14 pence per unit. From an output of 47,257 tons! in 1900, the output of the Central Provinces Prospecting Syndicate from this district has risen to 93,032 tons in 1906. In Sep- tember 1901 this same syndicate started work on a very large deposit near Balaghat town in the district of the same name, and has since then extended its operations to other deposits in the same district ; in 1903 the syndicate started work in the Bhandara district on the Chikhla (I) and Kurmura deposits 2. Starting with 47,257 tons in 1900 (from the Nagpur district only), the total production of this syndicate from these three districts in the Central Provinces has so increased that it reached the enormous total of 223,823 tons in 1906, this being more than 2 of the total output of the world for that year. The syndicate has now been registered as a limited liability company. The success of this syndicate soon led others to prospect the same areag H. D. Coggan, Jambon in the Central Provinces forfurther deposits, ee een On asy, with the resultant discovery of a large number Limited (Nagpur and previously unknown. In the beginning of 1902 3 Bhandara). Messrs. Charles Jambon and Cie., of Calcutta, started work on several deposits discovered through the agency of Mr. H. D. Coggan, and during 1902 and 1903 opened up the following deposits in the Nagpur district :—Sadtak, Parsoda, Mandri, Manegaon, Waregdon, Kacharwahi, and Pali. The output for the first year, 1902, was 15,423 tons. In January 1904 a company styled The Central India Manganese Company, Limited, was formed to continue the work of Jambon and Cie, Messrs. Killick, Nixon & Co., of Bombay, being the agents and Mr. Coggan continuing as general manager. The nominal capital of this company is Rs. 4,600,000, of which 2 lakhs were paid to the vendors and 1 lakh to the promoter’s syndicate. In 1905 this company started to open up various properties in the Bhandara district, namely Kosumbah, Sukli, Hatora, and Miragpur. The out- put of this company for 1906 was 83,964 tons. 1 This is the figure given me by the manager of the C. P. P. S. The figure returned in the mineral statistics is 35,356 tons. 2 Several of the Bhandara deposits, namely Sitapathur, Miragpur, Kurmura, Chikhla I, Sitasdongi, and Asalpani I, were discovered by Mr P. N. Datta, of the Geological Survey, in 1892-94 ; but the results were not made public. 3 Date of first application for a prospecting license—2nd December, 1901. 424 MANGANESE DEPOSITS OF INDIA: ECoNoMIcS. [Part III: In 1902, the late Mr. A. M. Gow Smith, on coming to the Central A. M. Gow Smith and the Provinces to prospect for coal in the Chhind- Beem are and Wara district, was led by the active export of Chhindwara). manganese-ore taking place from Nagpur and Kamthi to prospect for this mineral as well. He took up the Kodegdon! deposit in the Nagpur district, rejected by the Central Provinces Prospecting Syndicate on account of the small size of its outcrop, compared with the very fine deposits they had secured in other parts of the district ; and continuing into the Chhindwara district, discovered several previously unknown deposits?, some of them, especially Kachi Dhana, Sitapar, and Gowari Warhona, being very fine deposits. The Kodegdon deposits were opened up by a syndicate styled Messrs. Gow Smith, Dundas Whiffin, & Co., and some 8,000 tons despatched during 1903. After a report by Mr. H. Kilburn Scottin 1903 a limited company designated The Indian Manganese Company, Limited, was formed to work Gow Smith’s deposits. The capital of the company is £50,000, of which only 39,000 £1 shares have been issued, the amount paid up being £35,400 ; the amount paid for the acquisition of the mining property and rights was £25,000. Owing to the distance of the Chhindwara properties from the railway Kodegdon was the only one of this company’s deposits worked up to the end of 1905. During 1906, however, under the stimulus of higher prices, Kachi Dhana, Sitapar, and Gowari Warhona, in the Chhindwara district, were also opened up, the ore of the two former properties being carted to Chhindwara, and that of the last-named to Nagpur. ‘The output from the deposits of this company in 1906 was 16,543 tons. The mines manager is Mr. H. M. Hance, and the English agents of the company are Messrs. Everitt & Co., of Liverpool. The Indian agents were Messrs. Shrager Bros., of Calcutta, up till the autumn of 1905, and are now Messrs. Martin & Co., of Calcutta. In addition to those already mentioned, there are several other firms and individuals working in the Central Provinces, though on a less important scale. Messrs. Jessop and Co. of Calcutta own de- posits at Guguldoho and Bhandarbori in the Nagpur district, and Pacharé in the Bhandara district. The Nagpur deposits were Jessop & Co. (Nagpur and Bhandara). 1 Date of first application for a prospecting license—6th January, 1902. 2 Mr. P. N. Datta of the Geological Survey discovered Kachi Dhana and indica- tions of Gowari Warhona in the field season of 1893-94; but the discovery had not heen made public. CuaP. XXI.] HISTORY ; CENTRAL PROVINCES. 425 opened up in 1903 !, but no ore was despatched up till 1906, on account of the low prices previously obtaining. In this year the output from these two deposits was 4,721 tons 2, whilst 1,300 tons were obtained from the Pachara deposit during 1905 and 1906. In 1903, Mr. Cooverjee Bhoja of Calcutta secured prospecting GReees 2 licenses 3 over the Mandvi Bir, Junawani, jee Bhoja and the 7 : : Madhu Lall Doogar Mining Junapani, and Borda, deposits in the Nagpur Syndicate (Nagpur). district, and opened them up a little, with- out despatching any ore. As the result of various reports on these and other properties held by Cooverjee Bhoj , it seems to have been decided that they could not be worked under the economic conditions prevailing up to 1905. In 1906, however, a syndicate known as the Madhu Lall Doogar Mining Syndicate was formed to work the various deposits held by Cooverjee Bhoja. And under the influence of the enhanced prices of this year a beginning in the ] _. export of ore was made in March 1906, Setiecic pvaeear) Mining the quantity despatched up to the end of the year being 4,258 tons. Another syndicate holding deposits in the Nagpur district is the Bansi Lall Mining Syndi- cate, concerning which, however, I have no details. During 1904, Mr. P. C. Dutt 4 of Jabalpur acquired rights over Messrs, P. C. Dutt anq ‘2 _ Samnapur-Ukua-Gudma ore-band 5 in Burn &Co., the Carnegie the Balaghdt district. Later he was joined by See are a ae Messrs. Burn & Co. of Calcutta in his mining je enterprises, and together they secured several other deposits in the same district during 1905 and 1906. During 1907 Messrs. Dutt and Burn & Co. have disposed of most of their manganese properties. The Samnapur-Ukua-Gudma band has been sold to the Carnegie Steel Company of Pittsburg, United States of America, repre- sented in India by Mr. J. Kellerschon of Nagpur, the purchase price being, I believe, £12,000. Of the remainder of their deposits Shodan Hurki (Katangjheri I), Katangjheri II, Bhui Hurki (one of the deposits of this name), Kochawiéhi, Botajheri, and part of Ramrama, have been acquired by Messrs. Tata, Sons & Co. of Bombay, and are being opened up 1 Date of first application for a prospecting license—6th August, 1902. 2 This includes the ore extracted in 1903. 3 Date of first application for a prospecting license—12th January, 1903. 4 Date of first application for a prospecting license for manganese-ore—24th December, 1903, in the Jabalpur district. 5 Originally discovered by Mr. P. N. Bose in 1888-89, IT B 426 MANGANESE DEPOSITS OF INDIA: ECoNOMIcS. [Part III: by Mr. H. C. McNeill, late of the Central Provinces Prospecting Syndicate ; whilst Messrs. Dutt and Burn & Co. retain Ponia, Arjoni, Jém, and Ghondi, In the Chhindwara district, in addition to the deposits held by the Indian Manganese Co., there are one or two gree ae held by Rai Sahib Mathura Prasad of Chhindwara, the best of these being Devi, discovered in 19031. A certain amount of ore has been extracted from this deposit, but it is of low grade, and, as far as I know, none has been despatched to the railhead. During 1906 2 Mr. D. Laxminarayan of Kadmthi commenced to D. Laxminarayan Nagpur, open up various deposits in the Nagpur, Bhandara, and Baléghat). § Bhandara and Bélaghét districts, some of the properties secured being the ends of already-known deposits secured by other workers who were earlier in the field. But Parsioni in Nagpur, Karli (Asalpani II) in Bhandara, and Gaéraghat, Chikmara, and Chaukhandi, in the Balaghat district, are deposits not previously opened up. Laxminarayan claims to have extracted some 36,000 tons of ore from these deposits during 1906. Central India. After the Central Provinces the next area to which attention was 4 ’ directed was Jhabua State in Central India. awreee ete & Co. The occurrence of manganese-ores in this State seems to have been known at least as long ago as 1896. The original discoverers were apparently the local native officials who sent the mineral to the Political Agent for the Bhopawar Agency to find out what it was. A prospecting license was eventually granted to Messrs. Kiddle, Reeve & Co. of Bombay in May 1902, anda mining lease over the Kajlidongri deposit was taken out by this firm in May 1904, The first despatch of ore was in 1903, the amount being 6,800 tons. This has increased yearly up to 50,073 tons in 1906, the ore being derived almost entirely from the Kajlidongri deposit. Several other deposits have been discovered in this State, but most of them are of little value. The manager of Kiddle, Reeve & Co.’s properties is Mr. H. J. Winch. Cuap. XXI.] HISTORY: BENGAL. 427 Bengal. The deposits of manganese-ores and manganiferous iron-ores situated nH an , to the south of Chaibadsa in Singhbhum have oare, iller and Co, . - : ae ae sea ae aS ee nis arse 1880 Hae S$ by V. Ball. In 1904 prospecting licenses were a oe taken out by Messrs. Hoare, Miller & Co.!, and Mr. C. Aubert of Jambon and Cie. 2, both of Calcutta, over portions of these areas. A considerable amount of development was undertaken without any satisfactory results, so that both these firms abandoned their rights, which have since been assumed by the Madhu Lall Doogar Mining Syndicate. During 1906 this syndicate has accu- mulated about 1,000 tons, but has not yet been able to despatch it to the railway on account of transport difficulties. During 1907 deposits have been discovered in other parts of Singhbhum, notably at Leda Hill, but nothing has yet been done on them. Deposits have also been recently discovered in Gangpur ; one of these, Gariajhor, is of consider- able value. Bombay. In 1904, manganese-ores were discovered by Mr. T. B. Kantharia of > a ae Bombay at Talevddi in the Belgaum district, & Cie, & C. P. Boyce. hey were opened up by Mr. T. R. Frizoni on (Belgaum). behalf of Messrs. Jambon & Cie.* and in the middle of 1905 sold to Mr. C. P. Boyce of Belgaum. Although a fair amount of ore had been extracted, none of it had got further than Mormugao up to the end of 1907, Karly in 1905, Mr. T. B. Kantharia, followmg up an occurrence noticed by the late Dr. W.T. Blanford 4, T. B. Kantharia & the prospected the country round Sivardjpur in Cae the Panch Mahals district of eas The deposits discovered were taken up in the name of Mr. F. A. H. East 5 of Bombay and were later taken over by a company formed for the purpose, called The Shivrajpur Syndicate, Limited. The original capital was Rs. 1,00,000 in shares of Rs. 10 each. This was increased in August 1906 to Rs. 2,50,000 of which 20,000 shares had been issued at the end of this year. In February 1908 it was proposed to increase the capital to Rs. 5,00,000 by the creation of 1 Date of application for first prospecting license—7th January 1904. 2 Date of application for first prospecting license —6th February 1904. 3 Date of commencement of first prospecting license—3rd May 1905. # Mem, G. S. I., Vi, page 341, (1869). 5 Date of commencemens’ of prospecting license—5th July 1905. III B 2 428 MANGANESE DEPOSITS OF INDIA: ECoNoMIcS. [Part III: 25,000 new shares of Rs. 10 each. The managing agents are Messrs. Cory Brothers and Co., Ltd., of Bombay. The first shipment of ore from Sivardjpur took place during 1906, and the total amount of ore extracted up to the end of this year was 7,286 tons. In June 1907, a company styled ‘The Bamankua Manganese The Bkreaukun «Meee Company, Limited ’, was floated in Bombay nese Company, Limited. privately with a capital of Rs. 3,00,000, to (Eaneh Boba) work a deposit on Bamankua Hill, some 3 miles north of the deposit being worked by the Shivrajpur Syndicate. 2,428 tons of ore were extracted by this company up to the end of 1907. Mysore. On page 420 it is mentioned that the first definite account of the W. Ainslie, T. J.New. Occurrence of manganese-ores in India refers bold, and the Mysore to the find near Kumari in the Nagpur Geological Department. district of the Central Provinces, noticed by Jenkins in 1829. It is to be noticed, however, that Dr. W. Ainslie !, in 1813, says that this metal ‘ it is to be presumed, is not common in India. Captain Arthur, however, informs me that he found it in Mysore, massive, in an indurated ochre, combined with oxide of iron’. Newbold 2 also referred to the occurrence of ores of manganese in this State as early as 1840, whilst manganese-ores from Bangalore were exhibited at the Madras Exhibitions cf 1855 and 18573. There was no definite knowledge of the actual locality of any deposit of manganese-ore in Mysore State, however, until 1899, when Mr. H. Kelsall Slater, of the Mysore Geological Department, found some loose pieces of manganese- ore in the bed of a stream some 3 miles north-north-west of Kumsi in the Shimoga district 4. Mr. Slater also seems to have been the first to find manganese-ores at Shankargudda, Hoshalli, Shiddarhalli, Gangur, and near Shikarpur, in the same district ; and in the Kadur district, immediately to the east of Shiddarhalli >. In the Chitaldrug district manganese-ores seem to have been first discovered (also in 1899) by Dr. W. F. Smeeth and Mr. Sambasiva Iyer, in the Iplara Hills near Madadkere 6, and later by Mr. P. Sampat Iyengar 7 at several localities in the soft clays and lithomarges of the Chitaldrug belt of Dharwar rocks. 1 Mat. Med. of Hindoostan, p. 57. eee 2 Mad. Jour. Lit. Sci., XI, p. 45, (1840) : Jour. Roy. As. Sor., VII, p. 214, (1848) ; Op. cit., VIII, p. 155, (1846). 3 Jury Reports, 1855 & 1857. . 4 Rec. Mysore Geol. Dept., IV, p. 138, (1902-03). 5 Op. cit. V, pp. 45, 54, (1903-04) ; VI, p. 26, (1904-05). 6 Op. cit., II, p. 167, (1898-1899); IV, pp. 160,161, (1903-04). 7 Op. cit., VI, pp. 84, 92, (1904-05). Cuap. XXI.J HISTORY: MYSORE. 429 No attempt was made to open up these deposits until the end of 1904, Se eae ee a hc x when Messrs. W. T. Hamilton Holmes, J. and the Mysore Manganese Short, and Eardley Norton, took out prospect- Company, Limited. (Shi- jing licenses for some blocks situated near = Kumsi in the Shimoga district. In 1905 a syndicate, designated the Madras Mysore Mining Syndicate, was formed to take over these concessions. This syndicate obtained further concessions in this year. As the result of the opening up of these deposits, The Mysore Manganese Company, Limited, was formed and registered on the 9th March, 1906, with a capital of Rs. 10,00,000 divided into 10,000 shares of Rs. 100 each. Of this total Rs. 6,25,000 were paid up. In view of the fact that this company was the pioneer in the manganese industry in Mysore, it was granted a special concession. This took the form of an option over a reserved area with a radius of 13 miles from Ayanur in the Shimoga district ascentre. Within this area the Mysore Manganese Company are to have the first refusal of any concessions, for a period of three years up to the end of 1909, the Mysore Darbar reserving to itself the right to refuse any licenses that appear unnecessary or undesirable. Previous to the reservation of this area other licensees had taken out licenses over an area of 292 square miles situated within it. On the 31st January, 1907, a new company called The New Mysore The New Mysore Man- Manganese Company, Limited, was registered in ganese Company, Limited. London, with a capital of £150,000 in 150,000 Sa) shares of £1 each. Of these 50,000 shares were issued fully paid up to the Mysore Manganese Company, Limited, and the remainder allotted and fully paid up. The new company takes over all the mining interests and properties of the old company. It is proposed to raise a further £50,000 in the form of debentures to provide railway transport and open up the mines. The directors of the new company are nearly all interested in the Workington Iron and Steel Company, and the Moss Bay Hematite Iron and Steel Company of Workington; Mr. W. J. Eales of Madras is managing director and Mr. S. O. Stromquist, superintendent of the mines. During 1906 the Mysore Manganese Company raised 40,773 tonsof manganese-ore and exported about 37,000 tons to Mormugdo. The distance of the chief deposit of this company, namely Kumsi, from the Southern Mahratta Railway ter- minus at Shimoga is 29 miles, over which distance a light steam tramway of 2-foot gauge is under construction. Ofthisall but 1¢ 430 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part IIT: miles had been completed in September 1907, The chief deposits held by this company are those near Kumsi, Shankargudda, and Bikonhalli. The next company to be formed was‘ The Peninsular Minerals : __, .. Company of Mysore, Limited ’, which was regis- Grae a eee tered on 3rd September 1906, with 3, nomina! Figs and Chital- capital of Rs. 3,00,000, of which 250 shares ge of Rs.100 each were issued to vendors, whilst 2,000 shares of Rs, 100 each have been subscribed for, with Rs. 50 per share called up. This syndicate took over 15 prospecting licenses held by different individuals in the Tumkur and Chitaldrug districts. The chief deposits are round Karekurchi and Hoshalli in the Tumkur district, and reached from Bdanasandra Station, Southern Mahratta Railway ; and at Kenkere, Kittadhalli, and Madadkere, in the Chitaldrug district. This company produced 4,126 tons of ore during 1906. Another company called ‘ The Shimoga Manganese Company, Limit- ; ed’, with a nominal capital of Rs. 10,00,000; Miss A. E. Dawson and : * the Shimoga Manganese Was formed during 1907 to work various deposits Company, Limited. (Shi- secured by Miss A. E. Dawson of Bangalore. moe ene The deposits are situated round Shikarpur and Hoshalli in the Shimoga district, and in the Kadur district, just over the border of the Shimoga district to the east of Shiddarhalli. During the first half of 1907 some 4,000 tons of ore have been shipped by this com- pany. The agents are Messrs. Schréder, Smidt & Co. of Calcutta. The success of the Mysore Manganese Company lead to a regular rush for manganese concessions in Mysore and as a result enormous areas have been staked out by numerous prospectors, especially in the districts of Chitaldrug, Kadur, Shimoga, and Tumkur. A large number of these concessions doubtless contain no manganese-ore, and of those that do a large number must be of practically no value. Of those concessions known to contain manganese-ore may be mentioned Sédarhalliin the Chitaldrug district, held by Mr. W. W. Coen of Hubli ; Gangur and Kaginelli in the Shimoga district, and the Iplara and Nirugudda Hills in the Chitaldrug district, held by Mr. C. N. Surya Narayana Row of Bangalore ; and Sulekere in the Shimoga district, held by Mr. Subramania Moodaliar. There is also a syndicate—the Haji Prospecting Syndicate—holding concessions in the Holalkere taluk of the Chitaldrug district. Other concessionaires. CHAPTER XXII. ECONOMICS & MINING—continued. Statistics of Production of Manganese-ore in India. Sources of information—Detailed tables of production—Deposits that have yielded over 100,000 tons—Comparison of prices with production figures—Com- parison of Indian and foreign manganese-ore production—Exports of Indian man- ganese-ore—Distribution of Indian manganese-ore exports. Future prospects of the manganese industry in India. In the preceding paragraphs I have had occasion to make several references to the production or output from the deposits of the different operators working man- ganese-ore deposits in India. It will therefore be convenient to give here the detailed figures of production of manganese-ore in India. The only figures ordinarily accessible are those given in the Annual Reports of the Chief Inspector of Mines and the Annual Reviews and Statistics of Mineral Production in India. In the case of the Chief Inspector of Mines the figures are supplied direct by the local mine operators ; whilst in the case of the ‘ Mineral Production ’ the figures are obtained from the provincial governments,to whom they are supplied by the mine operators. The figures as published are not detailed, for although they show the output of each district and province, they do not show the output of each deposit, It is, however, a matter of considerable interest to know how the output is distributed among the various deposits. Hence I have obtained from the mine operators detailed figures of production, given separately for each deposit, as far as they have been kept. These are given in tables 28 to 34 on the following pages, whilst in table 36 are given the yearly totals for the producing provinces as they have appeared in the ‘ Mineral Production ’. Sources of information. It will be seen that my totals differ in many respects from those given in the ‘ Mineral Production’. This is due to various causes. In the first place, according to ‘The Indian Mines Act, 1901’, no working is officially regarded as a mine unless it has been worked to a depth of 20 feet, or extends beneath the superjacent ground. And unless a 452 MANGANESE DEPOSITS OF INDIA: ECONOMIcS. [Parr IIT: working is a mine in the official sense of the term, the operators are not required by the Mines Act to submit figures of output and labour for that particular working. Consequently, since many manganese quarries do not reach a depth of 20 feet until a year or two after the beginning of operations, the figures of production from some workings are liable for the first year or two to escape inclusion in the ‘ Mineral Production ’. This is not universally applicable, however, for many operators who have several deposits already officially declared to be mines, submit figures for the whole of their deposits. Another reason for the in- accuracy of the official figures of production is that some of the figures reported are not true figures of output or ‘ raisings ’, as they are often called ; but of the amount of ore despatched to the port of shipment, that is of the amount of ‘ despatches * or ‘ railings’. The figures I give in the following tables are fuller than those given in the ‘ Mineral Produc- tion’ because they include the output of several deposits not deep enough to be called mines. They are, however, only an approximation to the true output figures. For not only are there probably several small operators of whose existence Iam not aware, but some of the figures are, to my knowledge, ‘railings’. Thus the figures for Jhabua, which are the same as those given in the ‘ Mineral Production’, are entirely ‘despatches’ or ‘railings’. The reason of their return in this form is no doubt the greater convenience of the operators ; and, as the deposits are not in British India, the Mines Act does not apply, and consequently no objection can be taken to the return of the figures in this form. The chief reason for the difference between the figures I give for the output of the Central Provinces, and those given in the ‘ Mineral Production’, isa difference in the method of returning the output of the Mansar deposit in the Nagpur district. During 1900 and 1901 a large quantity of ore was quarried along the outcrop of this deposit, which lies along the top of a ridge. This ore was a considerable distance from the aérial ropeway that was constructed to tap another part of the deposit, and was therefore of no more use to the operators than if it had been left in the ground. Consequently it was not returned in the output figures for the years when it was ex- tracted. But the subsequent construction of gravity-inclines to tap this part of the ore-bed allowed of the shipment of the whole of this ore during 1905 and 1906, and it has probably appeared in the mineral pro- duction for those years. In the figures I give, supplied by the manager of the Central Provinces Prospecting Syndicate, this ore is entered up in its right place as regards date of quarrying. Cuar. XXII.] PRODUCTION FIGURES. 433 Table 28 gives in detail the production from each deposit in the Detailed tables of pro. Vizagapatam district, Madras, the district in duction. which manganese-ore was first worked in India. In tables 30 to 33 are given the detailed output figures for the four pro- ducing districts of the Central Provinces, the area in which work next started. The fluctuations in the output from these four districts are shown graphically in fig. 25. Table 34 gives the detailed output for all the re- maining districts and States, namely :—Singhbhum, Belgaum, Panch Mahals, Jhabua, Sandur, and Mysore. Table 35 summarizes the pre- ceding tables and shows the output for the whole of India by districts and States, whilst fig. 26 immediately following this table shows graphically the growth in the manganese industry in India, as regards output. Economics. 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XXII.] PRODUCTION FIGURES. 435 Since the preceding table was drawn up I have obtained information about the output of the Madras Manganese Company, which started operations on the first two of the deposits listed below in 1905, and on the remainder in 1906. It will be convenient to keep the detailed out- put figures for this Company separate from those previously given, which relate almost entirely to the Vizianagram Mining Company, Limited. It will be noticed that some of the deposits worked by the Madras Man- ganese Company have the same names as those given above. This means that this company has in these cases leased portions of the same villages as those in which the Vizianagram Mining Company is working. TABLE 29. Production of Madras Manganese Company (Vizagapatam district) during 1906. Deposit. Output 1. | Long tons. Devada2 F : . ‘ ‘ : é : a 1,642 Garividi . . : - 3 : + : 4 5 | 754 Gadabavalsa. ‘ ‘ : : ‘ . ; i 789 Lakshmipuram . - : : : . : : 5 603 Nimmalavalsa . ° : : - : - é | 165 Lingalavalsa . - : - : - - : : 32 Sarveswarapuram . 7 - 3 : - - - 87 Vijiarampuram . : - - : - 5 = 38 Bondapilli . . - - : : : . | 43 Batuva . “ : 4 , . : - 5 | 143 Viswanadhapuram . é ¢ ; : : : . 2 Challapuram . 5 o c : : : : 5 | 32 Garbham . : - : : : : . 5 st 36 Ravivalsa . | Chipurupalli | Toran 5 | 4,366 1 Figures supplied to the Deputy Commissioner of district. 2 Includes a certain amount of ore extracted in 1905. 436 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part IIT: TABLE 30. Detailed production of the Bdldghdt district in long tons. | | | Total for . | Total for | each 1901 1902 | 1903 1904 | 1905 1906 | each syndi- | deposit. |cate, etc. Central Provinces Prospecting Syndicite '. ( Thirori . F ce 361 ac An ae 2,088 3,449 | 2. , Ponia = = a a ne cme t we 4,742 4,742 | Lisameaea 5 2 on ste nb | 5c ea 4,059 4,059 | 6. Ramrama . - - os) eels ae - | AG 6,091 6,091 9. Balaghat . . - 3,839 41,614 7,898 10,323 16,246 78,499) 118,419 YEARLY TOTAIS . 3,839 1,975 |7,898 10,323 16,246 96,479 | 136,760 | 136,760 D, Laxminarayan 2, 2, Jamrapani . 2 - ate nt Fe ae ws 274 274 Garragh4t . ae ies se se ies 1,753} 1,7534 | & : Chikméra and Chaukhandi | ae 1 es 1,297 1,297 Sdonri . ; : Fo esses) cael | SE “i a2 339} 339} a | ee ie are | | YEARLY TOTALS Be ea he ac oo fw 3,418 3,418 | 3,418 P.C. Dutt and Burn & Co. Ukua (Samnapur, Gudma) . = 55 Nic 2,363 2,363 | YEARLY TOTALS : ce Be erat vate ae oe 2,363 ae 2,363 | GRAND YEARLY TOTALS . 3,839 |1,975 7,898 | 10,323 16,246 |102,260 | 142,541 | 142,541 Grand total for the whole district, 1GO1l—1; O6= 142,541 tons. ! Supplied by Mr. A. D. Sanders. 2 Supplied by Mr. D. Laxminarayan. ‘They are figures of railings. The total output from Laxminarayan’s deposits was given to me as approximately 23,000 tons, but as most of this was no despatched, it will probably be included in the output figures for 1907 and hence I have given the figures of railing, Cuar. X XIT.] PRODUCTION FIGURES. 437 TABLE 3], Detailed production of the Bhandara district in long tons. | | Total ; | Total | for each | 1901 1902 | 1903 | 1904 1905 1906 foreach | syndi- | deposit, |cate, ete. — ———— | __ — — Central Provinces Prospecting Syn- | | dicate \. 2. Sitapathur . “ =i 1,791 | 1,791 | 10, Kurmura (Ponw4rdongri) . | 248 Sor a 1,456 | 4,842 6,546 11. Chikhla I . . ° 499 | 5,112 | 4,998 | 8,559 14,791 : 27,678 61,637 | | | | = YEARty Torars . | 499 5,360 |4,998 | 8,559 | 16,247 | 34,311 | 69,974 | 69,974 | Central India Mining Co, 2 1, Kosumba F - : 8,105 | 17,682 25,787 3. Sukli % ° ° ° 3,519 , 16,529 20,048 4, Hatora ; ; P 113 2,509 2,622 5. Miragpur 5 - 5 | : ; 6,554 14,386 20,940 YEARLY TOTALS . 5 18,291 51,106 69,397 | 69,397 | Jessop & Co, 8 14, Pach4ra Sa Vane ‘ ; 700 600 1,800 YEARLY TOTALS . | .. i 700 + ~©=600~—-1,200 | 1,200 | | | a Tr pk Re le erie ere i | ery er D, Laxminarayan'. | Paraswdra Ghat . a : 16 16 13, AsalpénilI (Karli) . | y 11,873 | 11,873 hia SS eras ae = YEARLY TOTALS 5 | 11,889 . 11,889 | 11,889 So | alo ma <7 oer as cc GS GRAND YEARLY TOTALS e | 499 5,360 |4,998 8,559 35,238 l 97,906 152,560 Grand total for the whole district, 1901 — 1906 — 152,566 tons. rr re a ' Supplied by Mr. A. D. Sanders. 2 Supplied by Mr. H. D. Coggan, 8 Supplied by Mr. E. 8S. T. Davies ; evidently approximate. + Supplied by D, Laxminarayan; they are amounts of ore railed, 438 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Parr III: TABLE 32. Detailed production of the Chhindwara district in long tons. | | Total for Total for 1906 each each deposit. producer. ; | Indian Manganese Co.1 | 1, Kachi Dhana . ; = : - | 3357fS 3,713 3. Gaimukh 205 205 4, Sitapar 1,699 1,699 10. Gowari Warhona 1,269 1,269 TorTaL 6,886 6,886 6,886 Mathura Prasad. 7. Devi 600 600 Torar | 600 600 600 —————<—— a a GRAND TOTAL 7,486 7,486 7,486 Grana total for the whole district, 1903 = 7 486 tons. 1 Supplied by Mr. C. W. Walsh. Cuav. XXII.] PRODUCTION FIGURES. TABLE 33. Detailed production of the Néypur district in long tons. ! | | 439 | Total for | | Total \each syn- 1999.' 1901, 1902, 1903. 1904, 1905. | 1906, \foreach | dicate, deposit. | etc. Central Provinces Prospecting Syn- | | icate. ' 2. Gumg4on . af 3,117 1,731 | 1,981 220 | 2,409 | 3,222 | 12,680 3. RAmdongri ee 1,355 997 | 3,031 258 5,641 7. KAndri . | 20,940, 26,913 | 12,507 | 19,546 | 15,984 | 12,897 | 23,717 |132,504 8. Mansar 22,913, 27,031 | 15,924 13,523 13,293 16,497 | 18,731 | 127,912 14, Sétak 115 | 3,581 | 3,696 15. Beldongri . 3114) 4,004 | 5,347 | 1,585 | 1,344) 3,558 | 19,037 18. Lohdongri | 3,404) 15,395 | 19,140 7,207 1,331 | 20,922 | 39,970 | 107,369 YEARLY TOTALS | 47,257 76,925 | 53,396 48,601 32,413 57,215 | 93,032 | 408,839 | 408,839 Central India Min- e ing Co. 2- (50,437) 9. Mansar Ex- > al 835 637 | 1,472 tension. 1} | | 10. Parsoda . | | 160 494 654 | 14. SAtak 377 1,248 ' 3,193 | 4,818 | 19. Kacharwahi | | | 4 | 3,063 | 8,379) 5,340 16,782 Se 15,423 | 35,014; 4 i Bae, 20. Waregdon . | | 2,973 2,538 5,511 22. M4éndri | 11,745 12,769 4,471 28,985 | 224. Panchila, 1,791 | 1,791 | 23. M4neg4on . "| 5,576 | 8.297 | 15,525.| 29,328 YEARLY TOTALS re 15,423 | 35,014 | 24,729 | 3 ,754 | 32,858 139,778 |139,778 — —|—— = | Indian Manganese | Co. * | 1. Kodegéon . Ste | ais 11,434 9,000 11,094 9,657 | 41,187 ne ee ——— == a YEARLY TOTALS . oe | 11,436 9,000 11,094 9,657 41,187 | 41,187 u Supplied by Mr. A. D. ‘Sanders. The reason for the difference between these figures and those that have been incorporated in the Mineral Production is that the figures given here represent actual amounts raised, whilst those given in the Mineral Production are at least partly figures of despatch and not of output (See page 432.) 2 Supplied by Mr. H. D. Coggan. For the first two years the output figures of the various deposits were not keptseparately. Of the 50,437 tons of manganese-ore quarried in these two years, 1902 and 1903, probably 25,000 to 39,000 tons came from Waregaéon. 8 Supplied by Mr. C. W. Walsh for 1905 and 1906. Figures for 1903 and 1904 are of doubtful ac- curacy. No exact figures seem to be aVailable ; those given are pased on information from Various sources. “40 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part III: TABLE 33—~contd. Detailed production of the Nagpur district in long tons. } | | Total Total for 1900, | 1901. | 1902 1998. | 1904. | 1905. 1906, |for each each syn- | | deposit. | ‘icate, | = —___— Jessop and Co. } 24. Guguldoho re ee x Ve z Roe she 25. Bhandarbori Lvs ae | * is A is. 3,600 . —_———— (—— - | ——_- — YEARLY TOTALS. | ., be ae _ es Fone PAR 4,72! Mining Syndi- cate.2 } Madhu Lall Doogar | | | | | 29, 30, and 31. | MAndvi Bir, JunawAni, | and Junapé- | ni . : ee an eer ae Sealy) Goo -- | 4,258 | _——— YEARLY TOTALS . 4,258 4,258 4,258 D. Laxminarayan., * 7. Kandri 5 een ae or ee 5 Ae 849 12, Parsioni .| .. | .. he . hee of ; | | YEARLY TOTALS . a sy ete ws St Sc, 1,591 | 1,591 | 1,591 GRAND YEARLY TOTALS . . 47,257) 76,925 68,819 95,051 | 66,142 | 100,063 Rescage2! ee esc Grand total for the whole district, 1900— © 06=600,374 tons. a a FR FO RE A RR RR SR SE a 1 Supplied by Mr. E. S. T. Davies. As I saw a large quantity of ore stacked on the top of Gugul- doho Hill in 1904 and a smaller amount at Bhand4rbori, it is probable that the figures given here represent the amounts of ore despatched and not the amount quarried. I am not certain that the Guguldoho and Bhand4rbori of Jessop & Co. correspond exactly with the deposits that I have described under these names. 2 Supplied by Mr. Madhu Lall Doogar. Probably figures of ore despatched, and not of ore quarried and including ore raised in 1903-04. 3 Supplied by Mr. D. Laxminarayan, They are amounts despatched. 44) PRODUCTION FIGURES. Cuar. XX11.] TO $40,000) FOR 1907.7 * <— *SeOUT OI [VIJWOD OY} JO S}POLMYSIP JUOOYIP oy} JO WoNONposs os0-osouKsavUT jenuUe oy} SuLMoYs MeIseKT—~eg “Bur — 300 80 60 40 20 200 eo 100 “SNOL LO SANVSOOHL It 442 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Parr IIIT: TABLE 34. Detailed production of the remaining provinces, in long tons, | | Dis- \- Province. | District or State. Operator and Mine. 1903. 1904. 1905. 1906. trict fies , totals.) totals. fa eS ie PS os ee [VS | Bengal . | Singhbhum! . . Madhu Lall Doogar Min- ing Syndicate :— | South of Chaibfsa . .. he -. | 1,000 1,009! 1,000 Bombay . | Belgaum? P . C.P. Boyce :— Nersa ' 5 . a is 40; .. me Talevadi A 5 Ad A 600 234 874 | Panch Mahdls* . Shivrajpur Syndicate :— Sivar4jpur 5 = sc =: os 7,286 7,286 ToTaLs roR BoMBAY ee ” 640 7,520, .. 8,160 Central India| Jhabua* a . Kiddle, Reeve & Co, :— | Kéjlidongri . . 6,800 11,564 30,251 50,074 98,689 98,689 Madras . | Sandur® 5 . | Jambon & Cie. :-— Raémandrug . oi ates: ac 1,200! MAT) on Kannivihalli . : ete ae 34 2,762) .. TOTALS FOR SANDUR aC ac 1,200, 3,209 4,409 4 409 | | Mysore . | Chitaldrug’ . . | Peninsular MineralsCo. .. i Be 712 712 | ot Mysore é ' == == —- | Shimoga® ' . | Mysore Manganese Co. I | Short’sBlockk. .- .. = -. | 4,000 .. | Kumsi (Holmes’ Block) .. | .. | .. |36,773| .. | ToTaL FOR SHIMOGA aS ey -. [40,773 40,773) | [= ||. = ae | — ar ee ae a Tumkur’? . | Peninsular Minerals | Co. of Mysore . c Bi Ae of 4,827 4,827 hol a | TOTAL FOR MYSORE | ae se -- |46,812) .. |46,312 1 A rough estimate by Mr. I. Shrager. No ore despatched. 2 Supplied by Dr. C. P. Boyce. % Supplied by Mr. F. A. East. * Shipment figures, not production. 5 Supplied by Mr. C. Aubert and A. Ghose. ® Supplied by Dr. Smeeth, State Geologist for Mysore. 7 Supplied by Mr. R. T. Coggan. 443 EEE *su0} 1G°368'T= 9061 93 ZO6I L&3°868'T 193'868'T CGF TLS LEP‘ LES OeT OST T38°LLT O28 FFT 98L‘LaT 69368 Ga9'F8 086‘29 LOFEL 69896 91ST PRODUCTION FIGURES. OF ‘TT “vipuy JO 9JouM hte) Ioy IVIk YOR 1OF [epOT, ‘suoj Huo) ur ‘saouraord pun ‘saynjs ‘8702 ZIS"OF ZIS‘OF| LoS‘F | SLL‘OR|STL ZIS‘OF| L28'F SLL‘OF ZL “* oe * oe 4 2 |¢ ace ae TROL E 5 = | ee | a s | we “aU0sSAT ezo'ees | 9T9‘8es | GOFF | ZL0'TO6 OIL FTL | 686'F9 G09 84 FL0°S9 TLT‘89 SLE'OL 80026 Bo9'FS 086 ‘29 LOFFL 698'9¢ 9T8°ST OLF TL OS's “Te}0L \ Toe‘ IT 68L'89 ZC9'8S PL0‘89 TLT'89 GLP‘OL 800‘6 Zo9‘FS 086 ‘29 L9F ‘FL 6989S 98'S Olt TT OST’ tunjed ~VBUZIA *sVudval LL WOT VIPUL UI POSTBI a10 JO [BI0} PUBIN “quo, hon, 20106 | fae .. | 8,400 Ms | 22,758 1896-97 | 42,630/ .. ce 5. = .. | 4,700 | 47,330 1897-98 54,279 24,550 | 78,829 | | | 1898-99 51,931 10,944 | 62,875 ! | 1899-00 | 63,175 | 5,350 3 ot 8,350 | .. 18,350 Be 95,225 1900-01 86,269 | 13,300 5,850. 16,500 | 3,400 | 5,350 .. | 120,669 1901-02 | 65,150 | 11,300 15,000 | 41,720 133,170 1902-03 | 95,540 | 1,000 10,734 | 5,050 42,950 Italy, 4 155,274 } | | ewt. } Japan, i | | ewt. | 1903-04 | 110,506 | 19,288 | 2,050 9,985 3,500 .» | 35,880'| 25] edeeene 1904-05 64,705 | 25,015 | 10,800/ .. 5,300 10,750 | 64,375 _. | 180,945 1905-06 127,8563| 54,101 | 29,401 2 cwt. 2,400 3,900 | 96,835 10 cwts. 316,694 | Austria- | | Hungary 2,2 | | | | . 1906-07 | 219,607 | 98,581 | 33,485; — | 2,000! — 139,320 Austria- 492,993 } | Hungary | lcwt. | Total sent \ to each country. 1,001,0063/216,635 81,586 32,019 43,100 | 33,050 488,354 2,200} 1,897,951 Cuap. XXII.] prosPecTsS OF MANGANESE INDUSTRY. 457 The three great steel-producing countries—England, United States and Germany—take a large proportion of our manganese-ore ; the ex- ports to Holland and Belgium shown in the above table were in part for transmission to Germany, whilst the consignments sent to Egypt were booked to Port Said to await delivery to ports further west. Future Prospects of the Manganese Industry of India. On this subject I cannot do better than quote what I said in my paper * Manganese in India’, pages 121 to 124 :— * It will be noticed that no estimate has been given in this paper of the quantities of manganese-ore available in the deposits. This is not, however, because there is any need for pessimism on the subject. It is true that in the Vizagapatam district itis becoming more difficult to quarry the ore owing to the increasing depth at which it has to be worked; but in the Central Provinces there are several deposits con- cerning which it is easy to form estimates indicating the presence of millions of tons of ore easy to win. Owing, however. to the insufficient work which has been carried out in the way of cross-cuts and bore-holes . . . , these estimates are more or less of guesses, but there can be no desist wieiewee of their general correctness in pointing to the presence in the Central Provinces of vast quantities of easily quarried manganese-ore. * Nevertheless, at the present rate of output, with the rejection of all but first- grade ore, there does not seem to be much doubt that within a comparatively small ‘pericd of time, which one might guess at 30 to 50 years, the majority of the deposits at present known will have been worked out as far as the application of present methods of extraction are concerned. There will then still be left, both in the ground and on the dump-heaps, millions of tons of second- and third-grade ores and vast quantities cf manganese-silicate rock consisting largely of spessartite and rhodonite, and often carrying as much as 30 to 40 per cent of manganese. “This might be considered as rather an alarming prospect but for two counter- balancing considerations. One is that the deposits of manganese-oxide ores through- out the world are strictly limited in quantity, so that within a comparatively short time, which might be guessed as 100 years as a maximum, unless several fresh areas containing such deposits be discovered, all the easily won ores will have been removed from the earth. Long before that time, however, the price per unit of ese will rise sufficiently to enable the lower grade ores of the world, if not smelted on the spot, to be transported profitably to the smelting centres. Long before that time also the increasing difficulty and cost of getting manganese-oxide ores will probably compel metallurgists to turn their attention to the silicate-ores. * The second consideration is that long before that time, and let us hope in only a few years from the present, ferro-manganese smelting will probably have been introduced into India, thus rendering valuable the low-grade ores at present rejected, and so to a certain extent conserving the higher grade ores. * We are thus able to picture that within a comparatively smal] number of years, the easily-won high-grade Indian oxide-ores will become quite limited in quan- tity, and that, with the rising prices due to a similar state of affairs in other parts of the world, the manganese-miners will then find it just as profitable to work the lower grade ores and sort over their dump-heap3 as the tin-miners recently have in Cornwall to search their waste heaps for wolfram Following this, wil] come the time when spessartite and rhodonite will be regarded ss ores and just as eagerly sought as 50 per cent. oxide-ores now are. ir D 458 MANGANESE DEPOSITS OF INDIA: ECONOoMIcS. [Parr III: ‘Keeping in view these three stages of manganese-mining—high-grade oxide ores, low-grade oxide-ores, and silicate-ores, being each in turn the substance sought— it can confidently be predicted that manganese- “ quarrying,” and later on perhaps, manganese- “‘ mining,” has in India a long and prosperous future with possibly, however, bad times at intervals. « Nevertheless, it would not be out of place to draw attention to the desirability of stocking the low-grade and silicate-ores separately from the country-rock of quart- zite, mica-schist, gneiss or lithomarge, with which they are often indiscriminately mixed when consigned to the waste-heaps. ‘ Another aspect of the question has already been noticed by Mr. Holland1, namely the heavy loss which India, to all intents and purposes, suffers by exporting the raw ore. The average price that Indian manganese-ore fetches at its destination is about Rs. 30 per ton, and of this only about one-half goes to India, being divided between railways, carters, miners and land-owners. The remaining Rs. 15 goes mainly in freight charges. The mananese then comes back to India in the form of the steel it has helped to make, and In jia pays both the foreign manufacturer’s profits and the cost of return carriage. A recent quotation in the Enginecring and Mining Journal? gives the price per ton of 80% ferro-manganese as $85 to $175, equi- valent to about Rs. 265 to Rs. 546. It becomes obvious from this how desirable it is to manufacture ferro-manganese in India and thus keep in the country a proportion of the profits involved in its manufacture, even if the larger proportion of the ferro-manganese so made has still to be exported. The time must come, how ever, when the manufacture of iron and steel will be one of India’s most important industries, and then, of course, India will consume a large proportion of its own ferro-manganese.’ The foregoing needs no modification except as regards the estimate, which is of course only a guess, as to how long it will take to work out the deposits at present known by open-cast methods. The guess given is 30 to 50 years. Considering the sudden leap in the Indian production for 1906 and the fact that the production for 1907 is even larger, it seems as if India has captured a considerable proportion of the world’s market, so that even with the drop in prices recently experienced (end of 1907 and beginning of 1908) the production is not likely for the next few years to fall as low even as the figure for 1905. Bearing this in view I think that the 30 to 50 years is probably an over-estimate and that 20 to 30 would be a truer one for the number of years required for the working out of the ores at present in sight by open-cast methods, When I wrote the above, however, I had not seen the Sandur deposits. There can be no doubt as to existence of large quantities of manganese-ore—mostly second-grade, however—in the hills of this State. Making allowance for these I should be inclined to somewhat increase the estimate again, but not up to its former amount. With regard to the loss that India suffers by the export of manganese-ore in the raw condition see pages 541—3. : 1 Rec. Geol. Surv. Ind., XXXII, p. 62, (1905) _ 2 Jan. 27th, 1906, p. 212, Cuap. XXII] APPENDIX. 459 Appendix to Chapter XXII. I give below the output statistics in long tons of the mangancse industry in India for the year 1907 ; they were obtained too late to le incorporated in the tables given in this chapter. Tasie 43A. Totals District Prodac:| for Totals| Totals Province. or Operator. Deposit. te uC"! each |for each! for each State. Jon. | opera- | district.) province. | tor. 2a ee i: | Baluchi- Las Bela . Pabb ‘ 15 15 15 15 stan. | Syndicate. a ee ee 2 DY RETCAS | = | Bengal _—. | Singhbhum | Madhu Lalll 5. Gitilpi .| 1,804 | Doogar Mining Syndicate. | 7.Tutuguitn .| 2,229 3,533 Jambon &|6.Kalenda .| 400 400 | 3,933; 2,983! Cie. \ Bombay .| Belgaum .|C. P. Boyce} Talevadi t 500 500 500 Panch | Shivréjpur | Sivar4jpur .j; 19,689 | 19,689 Mahals. Syndicate. . Bamankua | Bémankua: .| 2,428 | 2,428 | 22,117 2,617 Manganese | | Co. { | Central Jhébua .| Kiddle Kajlidongri .| 35,7432] 35,743 | 35,743 | 35,743 India. Reeve & Co Central Balaghat .| Central { Thirori : 654 Provinces. Provinces i Pros pect- | 2.<~ Ponia .| 3,824 ing Syndi-| | cate. \ Jamrapani 2,064 6.Ramrama f| 2,114 9. Balaghét .| 92,182 /1,00,838 D. Laxmi- Tkirori -| 3,842 narayan. | 2. Jamrapani | 17,065 Gareghat. | 16,344 1,0°0 tons, retrvrned in tke 19(6 figures, deducted. Includes a small emcunt of ore won at Rambhapur. IyI D2 1 2 460 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part IIT: ee Totals District Produc-| for |_Totals Tota!s Province. or Operator. Deposit. ti a each |for each| for each State. ton. | opera- | district.) province. 4) tor. Central Balaghat— | D. Laxmi- Provinces—| contd. narayan. |Sdori . 812 | 37,563 contd. Indian Man- Langur e| 1,934 1,954 ganese Co. Tata,Sons Gudma . 4 5,000 5,000 & Co. | Caruegie Ukua . «| 14,400 | 14,400 | 179,785 | Steel Co z : ee Bhandara | Central 2. Sitapathur . 392 Provinces | Prospect- ing Syndi- cate. 10. Kurmura 337 11. ChikhlaI .| 38,840 | 39,569 Central 1. Kosumbah. | 29,397 India Min- ing Co. | 3. Sukli. 30,615 | | 4, Hatora | 2,121 5. Miragpor 34,300 Bhumian 2,794 Ramjitola .} 1,564 | 100,791 D. Laxmi- 10. Kurmura . 499 | narayan. | 13. Asalpdni II] 2,°44 | 3,848 | 143,703 Chbindwara |Indian Man- 1. Kachi 8,720 ganese Co. Dhana. | 8. Gaimukh 177 4. Sitapdr 9,869 10. Gowéri 11,952 | 30728 | 30,728 Warhona. Cuap. XXII.] APPENDIX. 461 a | | Totals | ; District Produc: for | Totals | Totals Province. or | Operator. | Deposit. eon 1 each jfor each for each State. * | opera- |district. province. | tor. | | | | a Central Jabalpur. | Carnegie . Mansakra 7,100 | 7,100 | 7,100 Provinces— Steel Co. | contd. i | ————— | | Nagpur .| Central 2. Gumgdon 12,860 | Provinces | | Prospect- | 3, Ramdongri 5,928 | | ing Syndi- | cate. 7. Kandri .| 30,307 | 8. Mansar .) 24,974 | 14, Satak 7,789 15. Beldongri .| 7,257 18. Lohdongri 40,418 1,29,533 peal = | Central 14. Sdtak 1,598 India Mining Co. | | | | 17, Nandapuri . 537 | 19. Kacharwéhi| 3,938 | 20. Waregdon . 528 22, Mandri 7,056 | 924. Panchéla | 536 | 23. Ménegdon .| 11,270 25,463 |Indian Man- 1. Kodegdon .| 7,527 | 7,527 ganese Co. ban: ie E Jessop& 24. Guguldoho.| 3,002 Co. | 25. Bhandarbori] 3,837 — Bhandachur 967 , 7,806 Madhu Lall| 29-31. Manavi_| 16,200 | 16,200 Doogar _—s Bir, Junawani Mining and Junapani Syndicate. a hi ee Ae ea D. Laxmi- 7. Kandri 12,066 | narayan. 12. Pérsioni . | 495 21. Khandala 221 | 12,782 | 199,311 540,577 ee 462 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [ParrIII: rn ne ie aie Tamra eS om Tia Province. Madras " ) Totals District ai eeLOE, Totals or Operator. Deposit. pres each eer | for each | State. = yee district. PP aaeae Sandur General 1. Rémandrug | 15,455 Sandur Mining Co. 2. Kannevi- 7,595 | halli. : 23,050 | 23,050 | 23,050 | x! | Vizaga- Vizinnagram| 1 to 5. The | 17,485 | patam. | Mining Co. Kodur Mines 7. Perapi 9,160 | 10. Govinda- 787 | | puram. | | 11, Garbh4am .| 56,262 | | | 13. Gadasim 459 14, Avagudem 7,929 15. Aitemyvalsa | 1,216 | | 18. Garuja 2,876 | 19. Perumali .| 2,709 20. Ramabha- 1,733 drapuram. Bajuvalsa. 32 Batuva 3 415 Boddam 2,378 | Chinna 27 Palavalsa. | Chipuru- £34 ! palli. | Dannanapeta &42 Devarapilli 419 | | Gadabavalsa 416 Jada . c 890 | Kottapetta 195 Lingalavalsa| 2,108 Naiduvalsa 54 Nellimarla. 3,942 Vedullavaisa 903 114,291 Cap. XXII eY APPENDIX. ] i} | District Province. or Operator. Deposit. |P rae State. ; eee se Sli. | | Madras— | Vizaga- Madras Baidapilli .| 1,155 contd. | patam— Manganese | contd. Company. Batuva -}| 1,070 | | Boddam 141 | Buthara- 61 | yavals:. Challapuram 440 | | Chinia 2,329 | Ranyam. | Chipurupalli 5038 Chok kara- 264 palem. | 4. Devéda 1,351 | Donnaya- 4, | | peta. Gadabavalsa 962 | 13, Gadasam . 54 lw Garbham . 3,961 | 1. Garividi .| 2,055 | 18. Garuja cH] 16 | a 16. Gotnandi 165 | | 10. Govinda- 1C0 | puram, | Gumadam . 586 | | | Gunpam 13 | Kondapalem| 40 | Kothavalsa 376 } Lakshmi- 3,672 puram. Lingalavalsa! 48 Mukkunara 5 Sannapeta, Totals for each opera- tor. Totals for each district. Totals for each province. 464 MANGANESE DEPOSITS OF INDIA: ECONoMIcS. [Part IIT: Totals District | Pict | ad Province. or Operator. Deposit. tion, 228 a5 for each State. OperTa- ai atrict, Province. tor. < Madras— Vizaga- Madras Nimmala: 754 coneld, patam— Manganese valsa. coneld. Company —coneld. 7. Perapi 2 19. Perumali . 640 Rayvivalea . ral Regati < Sarveswara- 81 ptram. | Sivandhora- 41 valsa. | Vedndavales 145 Viswanadhas 8 puram. | Viziaram- 2 21,878 | 136,169 159,219 puram. | Mysore Chitaldrug Peninsular | 691 Minerals | Co. of Mysore. Haji Prosp 1,000 | Synd. Various 1,434 | 3,125 licensees Shimoga . New Mysore 76,894 i Manganese | Co. Shimoga 15,72 Manganese i Co. Tata, Sons 1,427 i & Co. ) Jambon 816 & Cie. ' I i Various | i 1,725 | 96,591 | licensees. | | “a oa | | Tamkar Peninsular 13,091 | 13,091 | 112,807 Minerals Co. of Mysore. Cuar. XXII.] APPENDIX. 465 The figures of production for 1907 given above are summarized below :— Output for Output for ; District - Province. each district each or State. or State. province. Long tons. | Long tons. ie | : Baldewiciam. 0 =. 9 .~)bas Bela, . =. ». . 15 | 15 Bengal . See . | Singhbhum . : : ‘| 2,938 2,933 Bombay - ‘ Belgaum . + S : 500 Panck Mahéls ; . . «| 22,117 | 22,617 | Central India es . | Jhabua = - - 2 at 35,743 | 35,748 | Central Provinces .|Bélaghtt . . . . «| 159,735 | i) ee ae 143,703 | } Chhindwéra «Cw gts 30,728 | Jabalpur . 4 P = =| 7,100 fo en 199,311 | 540,577 Madras “ ; . | Sandur “ : 4 ; - 23,050 | Vizagapatam - - ° ° | 136,169 159,219 Mysore 2 - . | Chitaldrug . 2 : : 24 3,125 | Shine. stl ves yal 96,591 | | Siler # g Y oe a | 13,091 112,807 7 : ema ater | 873,911 GRAND TOTAL - ' The output recorded above shows that Kumsi—from which practically. all the ore mined by the New Mysore Manganese Co. is extracted— and Chikhla I are to be added to the list, given in table 38, of deposits 466 MANGANESE DEPOSITS OF INDIA: ECoNomics. [Part III: from which over 100,000 tons have been extracted. The list now stands as follows :— Se opt {eae Garbham . . . é : é : 553,149 46,095 Kodur : ; ; : : A ; 276,364 17,273 Balaghat . ; : ‘ s - 210,601 30,086 Kandri . . - : : : 175,726 21,966 Mansar?< \) 6S") A pees ee 154,358 19,295 Lohdongri 4 : : , j : el 147,787 18,473 Kajlidongri® . : ° c , = - | 134,431 26,886 Kumsi we bn ae cet mn Gey 56,833 Chikhla I : 5 : . 5 . ; 100,477 14,354 The total quantity of ore won from these deposits in 1907 was 425,121 tons; of this, 92,182 tons were obtained from the Balighat deposit, this being the largest output of any deposit in India in any year. The exports of manganese-ore for the year ending 81st March 1907 are shown below :— RR Port. Tons exported. Vizagapatam ’ . 121,735 Bombay : . : . . : . . ; 384,115 Calcutta c . . : . : c ‘ 42,569 Mormugio . ° : : “ : ; : : 99,962 § * Toran : 648,381 From this it will be seen that the production of manganegse-ore in India in 1907 exceeded the exports by over 200,000 tons. 1 Including the ore extracted by D. Laxminarayan. 2 Including Mansar Extension. 3 Including a little ore from Rambhapur. 4 Probably includes a smal] amount of ore won from other deposits. &’ Includes some 7,000 to 8,000 tons of ore mined in Goa. CHAPTER XXIII. ECONOMICS & MINING—continued. Labour and Costs of Production. Labour—Labour obtainable—Coolie wages—Contract and departmental labour —Absence of mining castes—Average daily number of workers—Benefits of the manganese jndustry. Costs of mining and transport—Cost of m‘ning—Of transport to railway—Of railway transport to port of shipment—Of handling at port of shipment—Of shipping to Europe and America—Insurance —Destination charges—Total costs of mining manganese-ore in India and putting it c.7. f. at foreign ports —Comparison of the cost of production of Indian, Russian, and Brazilian manganese-ores. Royalty, Labour. There is a considerable variation in the labour conditions obtaining in the different manganese-mining areas. The best miners I have seen are the Telugu-speaking natives of the Vizagapatam district,who seem to work considerably harder than the coolies employed in Central India and the Central Provinces. In Vizagapatam there seems to be no difficulty in obtaining a sufficiency of labour locally ; but in Central India and the Central Provinces there is often considerable difficulty in obtaining a sufficient number of coolies to keep the mines in full work. In Jhabua in Central India, the natives are Bhils, who, apart from being rather lazy and casual in attendance, cannot be obtained in sufficient numbers ; an additional supply of labour has therefore to be imported from other areas, such as Gujaratis from Ahmadabad. In the Central Provinces the labour locally obtainable con- sists of Hindus and the aboriginal Gonds. Here also the supply of labour is much less than the requirements, and consequently a further supply is imported from other parts of the Central Provinces, such as Raipur, and from other parts of India, such as Kachh in the Bombay Presidency. In Mysore the workers locally obtainable are Kanarese—mostly Lingdyats—, Waddas, and Lamb4dis; whilst Moplahs from Malabar, Waddas from Vellore in North Arcot, and coolies from the Western Ghats, are imported. In the Sandur Hills it seems that no labour is locally obtainable and that it has allto beimported. The imported coolies consist of Kanarese and Lambdadis from the districts of Bijapur, Dhérw4r, and Bellary. Labour obtainable. 468 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part III: ‘The wages paid to the ordinary coolies (men) and rezas (women) vary considerably from one area to another. The rates are shown in the following table as far as I have been able to ascertain them :— Coolie wages. TABLE 44, Rates foi coolie labour. rr DAILY WAGES. aa —_————— Men. | Women. | Children. —_— BENGAL :— = | Annas. | Annas. Annas. Siupubhun ~..- |. 20) ee eae 3 2 13 CenTRAL Iyp1a :— Jhabua “CA ru? ae oak ke a 1} 1} CENTRAL PROVINCES :— Balaghat 5 “ 5 : - 5 - | 3-6 | 2-3 | 1-2 Nagpur acy (S,.:-*9 uke A ee 24-34 1-2 MapRAS :— | Sandur . : - : 2 : : : 4-5 3 | 2-3 Vizagapatam . : : : : : . | 24-34 te ee 3-1 Mysore :— Shimoga 2 - : - : : - 5-6 3-4 2-3 Tamkur \. 5: Pies: ac" aati Gael Oe 2-3 1-3 It is only the ordinary unskilled coolies that are paid the above rates. Contract and depart. On account of the frequency with which the mental labour, coolies like to take holidays, owing to religious festivals or to the necessity of attending to crops, the mine managers find it preferable not to engage their coolies directly. The consequence is that most of the labour is supplied by contract, the contractor undertak - ing to extract and stack cleaned ore at agiven rate per 1,000 cubic feet Cnap. XXIII.) LABOUR. 469 measured as stacked, and to do dead-work at a given rate per 1,000 cubic feet of cavity made in the quarry in the case of soft ‘deads ’, or per 1,000 cubic feet of rock measured in tubs or stacks in case of hard ‘deads’. If the number of coolies employed by the contractor is small he pays them directly at about the rates given in the foregoing table ; but if he isa large employer of labour he sublets his contract to a petty or gang contractor, to whom the contractor pays asmaller rate per 1,000 cubic feet of ore and dead-work. The petty contractor pays his gang—with whom he himself works as a common coolie, for he is no more—at rates approxi- mating to those given in the table above. Some classes of work it is of course either impossible or undesirable to let out to contractors. Amongst such work is that of carpenters, blacksmiths, and men in charge of the winding gear at mines where ropeways or gravity inclines are in use, men engaged in supervising tram- ming, and men engaged in drilling and blasting. Such men are said to be engaged departmentally and are paid by the mine manager either daily or monthly wages, according to the nature of the work on which they are engaged. For the commoner classes of departmental work the rates of pay are the same as given in table 44; but a considerable portion of the work being of a more skilled nature than the contract work, much higher wages than the above are often paid. The difficulty of obtaining an abundant supply of good mining labour is partly due to the fact that the ancient mining industries of India have so long since decayed almost to the point of disappearance that there are very few people left whose caste work is mining. The consequence is that most of the coolies at present employed on the manganese mines have some other hereditary profession or trade, to which they like to revert at intervals. This particularly applies to the agriculturists, who have to absent themselves from the mines at certain times of the year so as to attend to the sowing and reaping of their crops. A further result of the coolies employed on the mines’ not being hereditary miners is that they have no hereditary mining skill to bring to their work. Never- theless, it often happens that whole families belonging to non-mining castes work on the manganese mines. Some of the children spend nearly the whole of their time on the mines practically from birth, and hence will grow up looking upon min: g as their legitimate and proper occupation ; from these, therefore, we may expect the evolution of a sort of mining caste during the course of the next generation or two. Absence of mining castes. 470 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Parr IIT: The following table ! shows the average daily number of workers— Average daily number’of men, women, and children—employed in the workers. manganese mines from 1895 to 1907 :— TABLE 45. Daily number of workers employed on the manganese-quarries from 1895 to 1907. A, | Year ending Bombay. Rey (Vase ae Mysore. ‘Total. | ° patam). | | | 30th June 1895 tei = 4c 600 to 1,100 600 to 1,100 30th June 1896 5k, e 1,200 | 1,200 31st December 1897 | 3s x2 | 2,750 | 2,750 31st December 1898 | ss hs 3,530 3,530 31st December 1899. - 4,780 | | “ase 31st December 1900. ee 4,242 | 4,242 3lst December 1901. 1,460 2,770 4,230 Sst Decombertg0o|) Al 2,081 | 3,966 | | 6,047 3lst December 1903... 4,003 2,939 (a) | | 6,942(b) 31st December 1904 125 2,010 1,980 (a) 4,115(6) 81st December 1905 48 2,566 2,508 876 (a) | 5,998(c) 31st December 1906 271 5,154 5,848 1,534 (a) | 12,607(d) 31st December 1907 1,099 9,23 | 8,419 (a) (a) |. ase) (a)—Figures not available. (b)—Exclusive of Central India ; the figures for 1903 and 1904 may be estimated at about 230 and 390, respectively, at 30 tons per person per year. (c)—Exclusive of Sandur and Mysore ; probably only a small number. (d)—FExclusive of Singhbhum (Bengal), Sandur (Madras) and Mysore, probably about 1,500 more persons. (c)—Exclusive of Singhbhum, Belgaum, Central India, Sandur, and Mysore. ? Compiled chiefly from the Annual Reporte of the Chief Inspector of Mines in Tndia, Crar. XXIII.] BENEFITS OF THE INDUSTRY. 471 The division of the labour in the districts of Bombay and the Central Provinces is shown in the following table :— TABLE 46, Daily number of workers employed in the manganese-quarries of Bombay and the Central Provinces, trom 1900 to 1907. BOMBAY. CENTRAL PROVINCES. Panch | Belgaum MahAls.| Total. Balagh4t. Bhand4ra. | Chhindwdra. Nagpur. | Total. 1900 (a) 1901 (a) (a) 1,460 1,460 1902 105 300 1,676 2,081 1903 = 385 75 2,543 4,003 Igo4 = 125 ze 125 | 295 64 os 1,651 2,010 do05 Sti 48 (a) | 48 | 362 300 cP 1,904 2,566 1906 = 48 223 271 | 1,836 973 | (a) 2,345 5,154 1907 ape | 1,099 1,099 2,663 2,230 | 416 3,924 | 9,233 (a)—Not returned, although work was progressing. From the figures given in table 46 it will be seen that some of the totals for the Central Provinces given in table 45 are defective, and one of those for Bombay. It is also to be noticed that the figures are in many cases returned only when a deposit comes under the Mines Act. Taking into consideration the fact that statistics for 1906 are not avail- able in the case of Bengal, Sandur, and Mysore, and are defective in the case of the Central Provinces, it is not improbable that the total average daily number of workers during this year was nearly 15,000. Taking the production totals for 1905 and 1906 as 245,627 and 513,488 respec- tively [including only Bombay, Central Provinces (except Chhindwara), Central India, and Vizagapatam, the areas for which labour statistics are available] the average number of tons extracted during the year by each worker is 40°95 for 1905 and 40°73 for 1906. Allowing for cases that have escaped inclusion in the Annual Report of the Chief Inspector of Mines for 1906 it is probable that the average Benefits of the man- daily number of workers engaged in manganese ganese industry. mining in British India was about 12,000. This is equivalent to nearly 10 per cent. of the total number of persons engaged 472 MANGANESE DEPOSTTS OF INDTA: ECoNOoMIcS. [Parr IIT: in mining of all descriptions during 1906 in British India. Itis, how- ever, an insignificant portion of the total population of India. Nevertheless, the influence of the manganese industry on the prosperity of the population of the areas where it exists is considerable. For in addition to coolies earning wages directly on the mines, a large number of the cultivators take up the work of carting manganese-ore, this often being a source of greater remuneration than actual working in the mines. Further, in areas, such as the Central Provinces, where there is a greater demand for labour on the mines than the available supply, the mines come into competition with the local Public Works Department and railway construction work, with the resultant forcing up the rates for coolie labour. That the manganese-mining industry has a beneficial effect on the population of the mining areas is shown by the fact that, during the last famine in the Central Provinces, the natives round Ramtek, finding constant employment and wages in the neighbouring manganese mines, to a large extent escaped the worst effects of the famine. But it must not be overlooked that the industry must often be regarded with disfavour by those not actually connected with it, or benefiting as coolies in the general rise of wages for coolie labour. Thus they may have to put up with the proximity of large coolie camps; the roads are often very badly cut up by the manganese-ore carting traffic; whilst those who want to employ labour find it more expensive. It has been suggested by one of the mining community that a portion of the royalties received by Goy- ernment from the manganese-ore industry might be applied in the manganese mining areas, either to reduce district cesses, or to improve communications, wells, schools, ete. Costs of Mining and Transport. The chief items in the cost of placing manganese-ore on the markets in Europe and America are the following :— 1. Cost of mining (labour, tools, plant, establishment). . Cost of transport to the railway. . Cost of transport to the port of shipment. . Cost of handling at the port of shipment. . Cost of shipping to Europe or America. 6, Destination charges. Cte OO bo 2 Cuap. XXIII] COST OF MINING. 473, The actual cost of winning the ore varies greatly from mine to mine, according to the characterof the deposit, the methods employed in working it, and the cost oi labour. The area concerning which I have the fullest information is the Central Provinces, to which the following remarks particularly apply, except where otherwise stated. In the sort of quarry that can be described as a hole in the ground the actual cost per ton is not very much greater than that paid to the contractor. The rate paid to the contractor per 1,000 cubic feet of stacked and cleaned ore varies from Rs. 30 to Rs. 60 (and sometimes as high as Rs. 75), according to the ease with which the ore can be won (the lower rates apply to detrital ore and the higher to ore in situ), the distance the waste has to be taken to the dumps, and the situation of the deposit with relation to labour centres. J am told that it is found by actual experiment that the volume occupied by one ton of stacked and cleaned ore ranges from about 15 to 19 cubic feet, the commonest values being 16 and 17 cubic feet. Taking 16} cubic feet as an average value, the weight of 1,000 cubic feet of ore is about 60 tons, so that the cost per ton of ore works out at 8 annas to 1 rupee according as the rate paid to the contractor is Rs. 30 or Rs. 60 per 1,000 cubic feet. To allow for the fact that the propor- tion of ore to waste is very variable even in one mine, it is customary on some mines to make a further payment of Rs. 5 to Rs. 6 per 1,000 cubic feet of the volume of the cavity made in extracting the ore. The addition to the cost per ton of ore due to this payment depends of course on what proportion of the cavity made was originally occupied by the manganese- ore. The most favourable case is that in which practically the whole of the mass of rock extracted is good ore. A good average value for the specific gravity of Central Provinces ore would be about 4:4 to 4:5. Allowing however for a certain amount of interspaces and friable ore which may be expected even in the most favourable circumstances, it will be preferable to take this figure as 4. One thousand cubic feet of solid ore of specific gravity 4 would weigh about 112 tons. Hence in this case the amount, if paid, for the volume of cavity made would be equivalent to about ? anna per ton of ore extracted. As the other extreme we might take a casein which only 1 ton of ore per 1,000 cubic feet of cavity was obtained. This would be equivalent to an addition of about Rs. 5 to Rs. 6 to the cost of extraction of ore per ton. Such ground would not of course be worked unless it were necessary as part of the deadwork of the mine. Five tons of ore per 1,000 cubic feet would be equivalent Cost of mining. It E 474 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part III: to an addition of about 1 rupee to the cost per ton of ore, and 10 tons per 1,000 cubic feet to an addition of about 8 annas. Since under certain circumstance s ground of this richness would be worked it will be seen that to the cost of 8 annas to | rupee paid per ton of stacked ore, there is another addition, ranging from 1 anna to 1 rupee per ton, to be made for the volume of cavity made in winning the ore. This gives a total of 9 annas to 2 rupees as the amount per ton of ore extracted actually paid to the contractor. This payment by volume of cavity made is more generally applied to detrital deposits where the proportion of ore to waste is very variable and the ground is soft so that the cavities can be squared up for measurement, than to solid ore-bodies, where blasting is necessary, and it is impossible to square up cavities fer measurement. In the latter case the ‘deads’ obtained from the ore-body are added to those obtained from the walls of the deposit and measured with them. At Kumsi in Mysore the payment made is Rs. 20 per 1,000 cubic feet of excavation in the ore-body. This includes breaking up the ore and removing the spoil, but not the ore from the working face ; no payment is made on stacked ore. There are however many other items that come into the cost of a ton of ore. Thus there is the cost of carrying out deadwork. This is sometimes paid on the size of cavity made. In one case in the Central Provinces it ranged from Rs. 35 to Rs. 60 per 1,000 cubic feet of cavity made, according to the nature of the rock to be quarried. In Sandur Rs. 20 per 1,000 cubic feet of cavity is paid for all-round earth-work. In many cases, however, the deadwork is paid for according to the volume as measured in tubs or stacks. The rates for this may be put at Rs. 6 to Rs. 50 per 1,000 cubic feet according to nature of rock being quarried, the lower rates (6—15) being the more usual. It is of course not possible for me to calculate what addition this makes to the cost per ton of ore. 't all depends on the amount of deadwork carried out. In cases when the working is carried out on the principle of taking out all the easily-won ore and neglecting all deadwork, except that absolutely necessary for the winning of the ore actually being extracted, this charge is very small. But when the management show any foresight and keep the future life of their deposits in view, doing a considerable amount of deadwork con- currently with the work of winning the ore, this addition may be considerable. There is also the cost of mining tools, such as drills, ham mers, crowbars, and shovels, and plant, such as ropeways, inclines, rails, and pumping machines, to be taken into account; and also the upkeep of the mining establishment and local offices. It is not possible for me Cuar. XXIII.] cost oF TRANSPORT TO RAILWAY. 475 to give the figure that should be added to the foregoing to give the true cost of putting a ton of ore on the stacks ready for despatch from the mine, The total costs af mimug (including establishment) are, however, placed by various men engaged in tle manganese-mining industry at Rs.1-8 to Rs. 3 per ton, and in exceptional cases as low as Rs.1 to Rs.1-4, or as high as Rs. 3-8 to Rs. 4, per ton. From these figures we can deduce that the cost of deadwork, mining plant and tools, and administration, is equi- valent to an average addition of about 1 rupee per ton, in some cases falling as low as about 8 annas and in others rising as high as_Rs.1-8. The figures given above apply only to the Central Provinces. I do not know what the total mining costs are for Jhabua, but I should think they are about equal to the lower value for the Central Provinces, say to about Rs.1-4 to Rs.1-8 per ton. In Vizagapatam on the other hand the costs of mining are probably sometimes about the same as in tiie Central Provinces ; but they must often be considerably greater, especially at such a mine as Kodur. For there, although labour is cheaper, such a large amount of deadwork has to be done per ton of ore won, and suck a lot of expensive pumping, apart from the distance the ore has to be carried up out of the pit, that I should not think the cost per ton can be less than Rs. 4 to Rs. 5. At some of the other deposits the cost may be a little less ; but probably the usual total cost per ton can be fairly put as ranging from Rs. 3 to Rs. 6. The actual rate paid to the contractors I ascertained, when in the district in 1904, to be Rs. 15 per 1,000 cubic feet of ore won, and Rs. 6 to Rs. 15 per 1,000 cubic feet of cavity made. Though these rates are considerably less than those paid in the Central Provinces, yet it must be remembered that the propor- tion of ore to cavity made is usually much less than in the Central Provinces. In Mysore the total costs of mining may be put at Rs. 2 to Rs. 3-8, averaging about Rs. 2-8. In Sandur they probably work out at about Rs. 3. All things considered, the cost of mining (including administration) Bist at femaport, to the noticed in the foregoing section is small in com- railway. parison with the total freight or transport charges incurred by the time the ore reaches the smelting centres. The first ireight charge is that of transporting the ore from the mine to the railway. When the industry first started ail this transport was effected by means of bullock-carts. These carry from 4 to ? of a ton, according to the size of the cart, and the extent to which the cartman likes to have his bullocks loaded up. The cost of bullock-cart transport varies consider- Ill E 2 476 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Parr IIT: ably in different parts of India, and, moreover, iseven in one district subject to considerable fluctuations, according to the season, the price rising whenever there is an increased demand for carts for agricultural purposes, such as for carrying country produce, e.g. cotton or grain. In addition to this there is a general tendency to an elevation of rates when- ever there are several companies operating in the same area, and a con- seguent competition to secure the means of transport. The following table gives a few rates obtaining between different mines and the rail- way. It must be remembered, however, that they only express general average values and that at certain times they may be somewhat wide of the true values :— TABLE 47. Rates per ton for carting manganese-ore. Average Deposit from |Railway sta- |Rates for whole dis- rates for | Distance | Annas per Area. which carted. |tion to which tance. whole dis- | in miles, mile of carted. tance. 4 distance. Bengall Gitilpi Chakardhar- | Rs. 3-12 Rs. 3-12 17 3°53 put. Tutugutu . Do. Rs. 6-4 Rs. 6-4 20 5°00 —_—. =! ee ——— —— Central Pro- | Beldongri . | Salwa 12 annas 12 annas 7 1°71 vinces. | Mansar Kamthi Rs. 2 to 2-8 Rs 2-8 15 | 267 Kandri Do. Rs. 2-8 to 4 Rs. 3 17 2°82 Kodegéon Nagpur Rs. 3-4 to 3-14 Rs. 3-8 22 =°54 Junawani . Do. Rs. 3-8 to5 Rs. 4 23 2°78 Kachj Dh4na | Chhindwara } Rs. 9 Rs. 9 30 4°30 Sandur Kannevihallj | Tornagallu | Rs. 3-8 Rs. 3-8 17 | 3°29 Vizag aataln’ Garbhém . | Garividi Rs. 1-4 to 2 Rs. 1-10 10 2° 602 miysore Kumsi Shimoga . | Rs. 6 Rs. 6 20 4°30 K4rkurchi | Bazasandra | Rs 1-6. Rs. 1-6 9} 2°32 1 These rates seem abnorma!ly high ; the cost of carting iron-ore from Turdmdih (44 miles) and Hakigora (9 miles) to. Kalimati station in quite another part of the Singhbhum district works out, however, at 4°5 annas per ton-mile. 2 Mr. Crawshaw tells me that the rates paid for carting work out at about 2 annas a ton-mile on Local Fund roads, and 2} annas on cross country tracks. Cuap. XXIII.] TRANSPORT TO RAILWAY. 477 From the foregoing table it will be seen that the most customary rate in the Central Provinces fcr the carting of manganese-ore is about 24 to 2? annas per ton-mile ; bit that in the case of deposits very near the station, like Beldongri, the tendency is for the rate to be lowered ; and that when the deposit is situated at a considerable distance from the railway. the tendency is for the rate to increase, as in the case of Kachi Dhana ; though it must be noted that a portion of the excessive rate in this case is due to the steep ascent up the ghdts on the way to Chhindwara, and to a steep descent and ascent in crossing the Kanhén river. The carting is usually done by contract in the Central Provinces, and the carting rates include the cost of loading the carts at the mines and the stacking of the ore at the railway station. In addition to this a charge of | to 1} annasis incurred in loading the ore into railway wagons. In the Central Provinces, however, bullock-cart transport is to a large extent being superseded by the construction of light tramways or railways. At present there are two such tramways constructed by the Central India Mining Co., Ltd. One of them, in the Nagpur district, joins the Manegaon, Mandri, Panchadla, Kacharwahi, and Lohdongri deposits _to the Bengal-Nagpur Railway at Tharsa, the total distance from Mane- gaon to Tharsa being 134 miles; the other, in the Bhandara district, connects the western Bhandara deposits. such as Chikhla, Kosumbah, and Sukli, to the Bengal-Nagpur Railway at Tumsar Road, the total distance from Kosumbah being about 34 miles. These two lines are of 2-foot gauge. On the Nagpur-district line the ore was at first carried by hand- tramming in trains of a few trucks each. But now this line, as well as the Bhandara line, has been converted to steam traction and the ore is hauled in trains of 25 to 30 trucks at a time, each truck holding 1 to 2 tons according to size. The Bdléghdt deposit has been con- nected directly to the 24-foot-gauge branch of the Bengal-Nagpur Rail- way known as the Sdatpura Railway, by a short line of 2 miles’ length. The last connection is the broad-gauge branch of the Bengal-Nagpur Railway running out to Ramtek, with a siding to Mansar and Kandri, a total distance of about 17 miles. This was competed and opened to traffic during 1908. Another line that would further decrease the need of bullock-cart transport is the proposed extension cf the Satpura Railway from Nagpur to Chhindwara ; another proposed branch of the Sdtpura system is a line from Mandla to Bilaspur, passing through Baihar in the Baldghat district, from which place a siding could be run out to Ulua. 478 MANGANESE DEPOSITS OF INDIA: EcoNoMIcS. [Part III: It is also proposed to run out a branch of the Bengal-Ndgpur Rail- way from Tumsar Road to Katangiin western Balaghdt, along the same route as the Central India Mining Company’s steam tramway : whilst there is also a desire for a line joining Katangi to Balaghat, but such a line has not yet been sanctioned. In Jhabua in Central India, Messrs. Kiddle, Reeve and Company have, nearly from the first, obviated the necessity of bullock-cart trans- port by the construction of a light 2-foot gauge line from Kajlidongri to Meghnagar on the Godhra-Ratlam Railway, a distance of 53 miles. This was at first worked by hand-tramming, but has, I believe, been now converted for steam traction. In the Sandur area a5} miles’ extension of the metre-gauge Southern Mahratta Railway has been constructed from Mariyamanhalli on the Hospet-Kottur Branch of the Southern Mah- ratta Railway to the unloading station of the aérial ropeway at the foot of the hill near Ramandrug ; whilst there is a proposition, now under consideration, of making further extension of about 20 miles’ length to Kamataru in the southern part of the Sandur Hills ; this will possibly be on the assisted -siding principle, by which the railway company supplies the permanent-way materia] and the mining company bears the entire cost of construction. The New Mysore Manganese Co., Ltd., is putting down a 2-foot gauge line for steam traction from the Kumsi mines to Shimoga Railway Station, a total distance of 20 miles, of which 10 miles had still to be constructed in September 1907. If this process conti- nues it is probable that in the course of the next five years most of the important deposits will be directly connected to the railway system of the country by some sort or other of light feeder line. This will of course set free a large number of bullock-carts, which, as before the start of the manganese industry, can be used in the fields, and for the carriage of country produce in cases where it is not also carried on the new railway lines. A large number of carts have been specially made for the manganese-ore traffic. But the owners of these will not have much cause of complaint at the disappearance of their lucrative occu- pation, ‘or their profits have in most cases probably paid several times over for tbe cost of the carts. This diminished demand for carts may have the advantage, as considered from the mine owner’s point of view, of causing the unemployed cartmen to take to mining, and so lessening the labour difficulty. As regards the cost per ton-mile of carrying ore on these mining lines I have little information. But I should think it would not average more than 4 an anna, inc.uding both the costs of working, interest on capital Cuar. XXIII.] cosT oF TRANSPORT TO PORT. 479 expenditure, and depreciation. In some cases it might rise as high as one anna, and in others be even as low as } anna (3 pies). But it is not probable that the lower figure will often be approached, for the rate charged on the broad-gauge line of the Bengai-Nagpur Railway is + pie per maund per mile, or 2:722 pies per ton-mile. The minimum rate that the railways are allowed to charge for the carriage of such freights as coa! and manganese- Se ore is of a pie per maund per mile, equi- valent to 2°722 pies per ton-mile.! The cost of railing the ore to the ports works out on this basis as follows :— TABLE 48. Rates for the carriage of manganese-ore to the ports over Indian railways. } | Mileage | a Freight Railway station to port. | Area tapped. Province. railway 8 station [Per tn. to port. R a. p. Champaner Road ) (| Panch Mahals | Bombay 270: | als 3 | || district. | | Meghnagar 5 || || Jhabua State. | CentralIndia | 361 |5 11! to Bombay . + | Balaghat . . | || Balaghat dis- >) (627 | 84 3 | trict. | | ee | iy Tumsar Road. J ) Bhandara and | | 570 |8 1 4 Balaghatdis-_ | tricts. | ricts i | Chhindwéra to Calew‘ta | Chhindwéra | | | yea Ue 7 . > district. | | | | Nagpur ‘ | 520 i 6 0 | oes Pro- J | Kamthi “ | || vinces. 29 ese 10 | | +tto Bombay .) | | | | Salwa =| | | Jp OSD iii Oe. } | | | { Nagpur dis- | | | Tharsa > =) | | trict. | 543 | 71 2 Nagpur. - | | 701 | 9 Lo) 0 to Calcutta .) | | Kamthi, : J _ 692 | 913 0 Garividi . - to Vizagapatam) Vizagapatam | Madras 5 56 {012 8 district. | | 1 One ton taken as equal to 27:22 maunds, 480 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Parr IIT: The Southern Mahratta Railway has not accepted the minimum rate of +th pie per maund per mile, and fixes the rates for each station separately. The rates quoted by this company consist of two portions, freight charges, and wharf dues at Mormugido, to which port all the ore carried by this railway is taken. The freight rates from the various exporting stations to the port of Mormugao are as follows :— TABLE 49. Rates for the carriage of manganese-ore to Mormugdo by the Southern Mahratta Railway. | Mileage from railway | Freight ailway Station. Area tapped. Province. station | per ton. to Mor- mugéo iz. = 1 a? 1 Rémanamalai (Ramandrug) 1) 253 | 5 12 3 Sandur Hills) Madras .< Tornagallu 5 L ia) lan ieee were 4) Harihar lh) 223) ude al eO | Chik Jajur .|$ Chitaldrug |> if 260 |5 5 6 | district. | | Holalkere . 3|[} | | 266 | 5° 7 9 i | | Tarikere ala) | | SLT” RO SLORNO | ‘Mysore. .4 Benkipura .| & Shimoga dis | | | 330 6 12se3 | Siaient. | | Shimoga a8 | | 340 | 512 3 | | Banasandra Tumkur dis | j Ll 300) 4) 68 sdan0 trict. At the rate of 1,th pie per maund per mile the freights from Rémandrug and Shimoga to Mormugio would be Rs. 3-9-5 and Rs, 4-13-1 respectively. On the Bengal-Nagpur Railway steel trucks are used for the c¢ar- riage of manganese-ore ; they hold from 14 to 16 tons of ore each. It used to be the custom to run each truck on to a weigh-bridge to ascertain the exact amount of ore loaded into it. But the traffic has now grown to such an extent that it is a matter of considerable inconvenience to do this for every truck. Consequen'y it has been decided to load by measurement. Experiments have been made in which a large number of wagons loaded up to a certain mark, so that the volume of loose ore Cuar. XXIII.) COST OF HANDLING AT PORT. 48% contained in each is known, have been weighed, and a figure fixed for the average relation between volume and weight of the ore. In the case of the Central Provinces Prospecting Syndicate it has been decided that the correct figure is 16 cubic feet to the ton. And to allow for any losses, they are allowed by the railway to load on the assumption that 164 cubic feet of ore go to the ton. For each company’s ore the figure has to be determined separately, but it is seldom that the figure exceeds 17 cubic feet to the ton. In cases of operators railing only small quan- tities of ore actual weighing is still resorted to. For loading by volume a horizontal chalk line is drawn round the inside of each wagon at the height above the bottom of the wagon to which it has to be loaded in order to take the amount of ore the truck is allowed to carry. This loading is done from the ore stacks at the station by men, women, and children. The cost of this is about | to 13 annas per ton, and is paid by the mine operators. In cases where the ore has to be transferred from wagons on the narrow gauge to wagons on the broad gauge, the transferment is done at the expense of the railway. Such is the case at Gondia, where ore carried from Balaghat and Chhindwara on the Sat- pura Railway (2}-foot gauge) has to be transferred to broad-gauge wagons. For the carriage of the Central Provinces ore to Bombay whole trains are usually employed. ; When the ore-train arrives at Bombay the ore is dumped and stacked on the storage ground at Malet Bandar ; or if a ship is waiting to be load - edthe oreis carted or trammed at once to the Cost of handling at the qdock side. Here it is dumped in heaps on the re Bomby: edge of the wharf and transferred to the ship by means of buckets attached to the ship’s slings or derricks. To obviate the delay and uncertainty involved in carting the ore from the storage ground to the dock, a dock tramway has been constructed from the storage ground at Malet Bandar to the dock. The dumping at the storage ground is usually necessary ; for it is necessary to have a stock of ore on hand so that there may be no shortage of ore when a ship is ready to be loaded. The charges per ton usually incurred at Bombay ! are as follows :— A. ». Unloading wagons and stacking on dump 5 2-0 Siding charge. : : : : : : : C 2-0 Railing to dock on dock tramway : 2 : 4 c = 10-6 Wharfage (including the loading into ships). é : é - 8-0 Rs. 1-6-6 1 Kindly supplied by the Secretary to the Bombay Port Trust. 482 MANGANESE DEPOSITS OF INDIA: Economics. [Parr III: When the ore is carted to the dock instead of being railed on the dock tramway, the cost varies from 6 to 10 annas, according to lead and other circumstances. Stacking ground rent at Rs. 7 per 500 square feet is also charged. The third item can sometimes he avoided by arranging to rail the original ore-train into dock a short distance from the vessel. The ore can then be unloaded by Dock Contractors and dumped along- side the vessel. The charges would then be as follows :— A. p- Unloading wagons and dumping by the side of the vessel . “ 1-6 Siding charge . : - : 2-0 Wharfage . 8-0 11-6 The charges incurred at Bombay vary therefore from 114 annas to Rs. 1-8, the latter limit being given to allow for the fact that there are often expenses incurred by the shippers that are not included in the foregoing figures. Rs. 1-4 can perhaps be taken as an average figure. Manganese-ore railed to Calcutta has to be ferried across the River Hughli from Shalimar to the Kidderpore Docks in the Bengal-Nagpur Railway steam ferry-boats, which carry 23 railway wagons each. This “charge is appar- ently included in the cost of railing the ore from the forwarding station to the docks. The charges per ton incurred at the Docks are! :-— Calcutta. A, p. Dumping on wharf pendine shipment . : : 5 : : 2-0 Shipping charge : : : : . : - : 6-6 River due . 5 : : ; . : : 5 : : 1-6 10-0 As extra charges there are :— If shipped at night . : : : : : : : ; 1-0 Removal if incurred . . : : ; 5 4-0 Rent, if incurred, Rs. 4 per cottah per month. The dumping charge may be avoided if the ore does not have to wait pending shipment. The Calcutta charges vary therefore from 8 to 15 annas, with an average figure of about 10 annas. At the Port of Vizagapatam the railway siding is on the beach, where the ore is dumped from the railway wagons; from there it is taken by a short lead to the surf boats and carried out in these to the steamer lying Vizagapatam. 1 Kindly supplied by the Secretary to the Commissioners of the Port of Calcutta. Cuap. XXIII.] cost oF SHIPPING TO MARKETS. 483 outside the surf. An occasional loss of ore is suffered in this process through the capsizing of a surf-boat. In the case of one company the shippers charge Rs. 1-2 per ton from railway wagons to ship; in addition to this there are port dues of 2 annas a ton to be paid. At the port of Mormugao the Southern Mahratta Railway! has charge of the shipping arrangements. Conse- quently the Railway Company quotes not only freight rates from the forwarding station, but also the charges incurred at the Port, grouping the latter under the heading of wharf dues. The total of freight rates plus wharf dues include the loading of the ore into trucks at the forwarding station, unloading it at the stacking ground at Mormu- gao Harbour, loading again into trucks and putting the ore into trays alongside the steamers ; they do not include, however, the cost of hauling on board or distributing the ore in the holds of the steamers. The cost of hauling on board comes to 1 anna per ton, and the trimming in the hold is included in the steamer freight rates. The wharf dues charged by the Southern Mahratta Railway are now Rs. 1-2, but were formerly only 9 annas per ton. Including the 1 anna for loading on board the total charges now incurred at the Port of Mormugao are Rs, 1-3. The ocean freight rates charged for carrying manganese-ore from Indian ports to those of England, the Continent, Cost of shipping to Europe and America, depend on whether itis shipped and America. : : as whole cargo, or as dead weight forming only a portion of the cargo. From Bombay whole cargoes are often sent, but part cargoes only are shipped from Calcutta. The rates from Bombay to England and the Continent, are stated 2 to have been, in August 1906, 16 shillings for whole cargoes and 14 to 15 shillings for part cargoes; whilstt he ordinary variation in freight rates for manganese-ore from Bombay is between 15 and 20 shil- lings per ton to England and the Continent, and 164 to 20 shillings to America. A fair average rate is probably about 16 shillings or Rs. 12 to England and the Continent, and 18 shillings or Rs. 13-8 to America, At present (September 1907), however, the rates are up and are stated to be 174 shillings for part cargoes and 19 for full cargoes to the United Kingdom, and 20 shillings for full cargoes to America. In Calcutta there isa liner’ s conference, which has fixed the minimum rate of freight on ore Mormugao. Hi I am jndebied to the Traffic Manager, 8. M. R., ise the following cafoemeons 2 C. E. Low, Gazetteer of the Balaghat District, page 231, (1907). 484 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part III: to English and Continental ports at 15 shillings a ton, though it has been as low as 10 shillings for part cargoes. It is said, however, that this rate (15s.) is not often obtainable unless steamers are short of other cargo, and that 17 shillings and 6 pence is a fair average rate. This is equi- valent to Rs. 13-2 per ton. The rates from the port of Vizagapatam are usually about the same as those from Calcutta. They.are now (September 1907) up and said to be as high even as 22 shillings for full cargoes, and a little less for part cargoes when such are obtainable. These rates probably apply to ore shipped to America, however, and would be less for United Kingdom and Continental ports. The rates from Mormugao vary from 12 to 20 shillings according to the state of the freight market and were stated to be 184 to 20 shillings in August 1907, for full cargoes to United Kingdom ports. It is also customary to insure the cargo against loss. This is reckoned by adding 10 per cent. to the c.7.f. sale price of Engurenee. the ore, and taking 3 per cent, of this value, On a 50 per cent, ore the marine insurance would therefore vary from 33 annas to 63 annas per ton, according as the c.7./. value of the ore varied from 9 to 16 pence per unit. In the estimate (page 486) of the total cost of putting the ore c.7.f. on the market I have included this charge in the ocean freight. When the ore arrives at the port of destination there are various | A 0 4 0 | amo 8. Royalty to proprietor | Lo Cems. | vyc.t |. ease 9. Rent to state . ° aa ay oraz i ee oa 10. Agent's s commission er BOTTI Total cost f. 0. b. at port 2911/25 310/16 710/19 8 3/14 0 0| 815 0 P | 11. Ocean freight to Toudon, = —; ; ‘ 9 0 O(c)/ 9 0 O(c)| 10 1 2(c)) 913 9| 12 0 0] 18 8 O 12. Destination charges | Ome ON cien Gin 0) Nace () | VE) Total cost ¢.i.f. at Lon- | | | don. 22: 15 1 | 35 910/26 9 O | PHY Oe (ei) ca LY (0) | egy all, (4) 1 Annales des mines de Belgique, X, p. 848, (1905). (a) Included in item 2, _ 2 Loc cit, p. 886. (b) Probably included jn item 1. 3 Trans. Am. Inst. Min, Eng., XXVIII, p. 207, (1898). (ec) Limits Rs. 6 to Rs, 15, * Includes taxes. Royalty. In the foregoing figures of the cost of delivering manganese-ore at the ports of the countries where it is to be used, I have not included Ill F 490 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part IIT: royalty (except in table 52). According to a resolution of the Gov- ernment of India—Department of Revenue and Agriculture, Geology and Minerals, No. 18—17-2, dated Simla, 20th May 1899—grantees of prospecting licenses and mining leases shall pay a royalty on all minerals won, at the rates specified in Schedule C attached thereto. Manganese-ore comes under the following section of this Schedule :— ‘Copper, tin, lead, or other metals . 24 per cent. on the sale value at the pit’s mouth or on the surface, of the dressed ore or metal, convertible at the option of the lessee to an equivalent charge per ton to be fixed annually for a term.’ This resolution applies to the grant of licenses and leases only in British India. In the Native States a fixed royalty irrespective of market price of the ore is usually arranged when a prospecting license or mining lease is granted. The rates prevailing in various States are as follows :— TABLE 53. Royalty, in annas per ton, levied in certain Native States and Zamindari Lands. Annas. Jhabua State, Central India a! ie ib Mysore State .. se a Sc 6+24°% on pro- fits over 10% of capital.! Sandur State, Madras 5 “ts os 6 The Vizianagram Samasthanum, Madras ee 4 In the Central Provinces, however, where the deposits are all in Bri- tish India, the rates are levied on the principle of 24 per cent. on the wholesale value of the ore at the pit’s mouth. In 1903 the rate levied was 1} annas per ton. This was decreased to | anna per ton in 1904 when the price of manganese-ore was rapidly approaching its minimum value. During 1906 the rate was again raised to 2 annas, and later in the year to 4 annas per ton, this rise of royalty corresponding with a rise in the price per unit of manganese-ore. It is obvious, however, that the elevation of the royalty in 1906 was not nearly enough, even on the 2} per cent. basis, if it was to have kept pace with the rise in the price of the mineral. When the price of manganese-ore per unit rises above 11 pence, then the profits of the operators increase enormous- 1 There is a proposal on toot to consolidate this to a royalty of 10 annas per ton. Cuap. XXITI.] ROYALTIES. 49] ly, and it is certain that a substantial increase in the royalty levied by Government would still leave a very handsome profit to the operators. [The royalty levied in the Panch Mahals district of Bombay is 14 annas a ton.| In any case, however, a sliding scale of royalties should be drawn up, so as to admit of the alteration of the royalty from time to time according to the price of manganese-ore per unit, the royalty levied being on a basis of 23 per cent, of the pit’s mouth value of the mineral. In con- structing this scale of roya!mes it might seem as first sight as if it should beso drawn up as to take into account the differences in the quality of the ores from different deposits, the different distances of the deposits from the rail, the differences in the cost of winning the ores, and the fact that contracts for the supply of ore are often made a year or two ahead. This would, however, be so exceedingly complicaied and so difficult of application, and would lead to so many disputes, and also to invidious distinctions between different firms, that it is desirable to avoid it, The average percentage of manganese in the ores exported from the Central Provinces can be taken as about 52. Hence if the royalty be fixed on the assumption that all ores are 50 per cent. ores, it would on the average be in favour of the operators. Hence, for the construction of what I think would be a fair schedule of royalties, I have taken a basis of 50 per cent, of manganese in the ores, and the quotations of the price per unit of first-grade ore as given in the Mining Journal, London. For the calculation of this table of rates it is necessary first to cal- culate what would be the pit’s mouth value of the ore at the various prices per unit. Judging from the figures given in table 50 on page 486, a very fair average value for the cost of delivering the manganese-ore at the ports of des‘ination would be Rs. 26-14, this being the value for the Central Provinces ore exported wid Bombay. For the purposes of calculation Rs. 27 can be taken. Now the difference between this value and the price per ton the ore will fetch at the contract price when landed at the port of destination is the actual profit made by the operators. The true value at the pit’s mouth is obtained by adding to this profit the cost per ton of quarrying or mining the ore and stacking it onthe mine. The average value for this is Rs. 2-12. Now at a price of 10 pence per unit, the price received per ton of ore is Rs. 31-4. Taking the average cost of delivery c.7.f. at the port of destination as Rs. 27, then the profit per ton at this price is Rs. 4-4. Adding to this the cost of mining, Rs. 2-12, the pit’s mouth value works out at Rs.7. The lll F 2 492 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part IIT: royalty on this at 2} per cent. is 2°8 annas or, to the nearest half anna, 3 annas. On this basis 1 have drawn up the following table :— TABLE 54. Royalties in annas per ton leviable on Central Provinces manganese-ore at 24% on pit’s mouth value. 1 4 3 4 5 6 7 Pit’s mouth | Price per | Yalunet st’ | Prost per | value (ig “aly levi | levtble ae | Rovelly Jove fatade cif. at Eng- | uresincol- umn 3 plus ee en oie wee to 12 pence a ore. | tinental ports. | Hy)’ | eoatofmm- | mouth | |” estlhalt |) Que mag ee ing). value, anna). Dene Pence. Rs. a. Rs. a. Re: «ae Annas. Annas. Annas, 8 25—0 Nil. 2—12 1°10 | 1 1 9 28—2 1—2 3—14 1°55 14 14 10 31—4 4—4 7—0 2°80 3 3 1 345) | 9 72g 10—2 4°05 4 4 12 37—8 10—8 13—4 5°30 5h 53 13 40-10 | 13-10 16—6 6°55 64 13 14 2319 ee =a. 19—8 7°80 g 16 15 46—14 | 19--14 | 22—10 9°05 9 18 16 50—0O | 23—0 25—12 10°30 103 | 21 17 ss—2 | 26-2 28—14 11°55 1; | 28 18 56—4 29—4 32—0 12°80 13 | 26 It seems to me that the best way of levying royalty according to this schedule would be to fix it on the first of January every year, on the basis of the true mean of the prices quoted in the Mining Journai during the preceding year. As, however, the average price of first grade ore during one year may be considerably higher or lower than during the previous year, it would be necessary to bring about an adjustment at the end of the year between the royalties actually paid by the operators and the amounts payable on the basis of the average price during the year under consideration. Thus if the rate had been fixed at the beginning of a given year on the basis of an average price of 11 pence per unit during the previous year, and at the end of this given year it was found that the average rate had risen to 13 pence, then the mine operators should be required to pay to the local government an amount per ton equal Cuap. XXIII. ] ROYALTIES. 493 to the difference between the royalties that would have been leviable at the two different average prices per unitof manganese-ore ; whilst if the average rate had fallen during the year to 10 pence, then it would be necessary for the Government to make a refund of the difference per ton between the royalties leviable at the two different rates. This might be actually returned by the Government in cases where the operators had actually ceased to work, or set aside towards the payment of the royalties leviable during the ensuing year. This sounds rather compli- cated, but in practice it would probably prove easy of application, and satisfactory to the mine operators. CHAPTER XXIV. ECONOMICS & MINING—continued. Valuation and Chemical Composition of Manganese- ores. Valuation of manganese-ores—Mining Journal prices—Schedule of the Carnegie Steel Company—Requirements made less stringent during 1£06—Special prices— Valuation of ores for chemical purposes—Nomenclature of manganese-ores and manganiferous iron-ores—Ferruginous manganese-ores. Tables of analyses of Indian ores—Summary of tables of analyses—Analyses of Indian ores expected by buyers. Analyses of manganese-ores of the World—Analyses of cargoes of Indian and foreign ores tanded at Middlesborough—Analyses of the manganese-ores of the world. The less important constituents of Indian manganeése-ores—Alumina—Baryta— Lime—Magnesia—Potash—Soda—Arsenic—Sulphur—Cobalt and nickel—Copper— Lead—Zine—Titanium—Combined water—Carbon dioxide. Valuation of Manganese-ores. As has been explained on a previous page, the price per ton of man- ganese-ore obtained on its delivery c.2.f. at the port of destination is subject to great variations according to the price per unit of manganese. On pages 415-6 is given a table showing the fluctuations in the price per unit of manganese for ores of different grades since 1890, as quoted in the Mining Journal. The variations are illustrated by a diagram (fig, 23) on page 417. On pages 447-9 I have considered the relation between the prices of man- ganese-ore at different times and the Indian output Mining Journal prices. The prices given in these tables are for the three grades into which manganese-ores are, for commercial purposes, classified :— Ist grade sis ae 50% Mn. and upwards 2nd grade ms 5S 47—50% Mn. 3rd grade Lys 58 40—47% Mn. As an example of the way in which the schedule of prices is applied we can take the case of a 52% ore from the Central Provinces in January 1907. The average price at this time was 154 pence per unit. The price then per ton paid or this ore would be 52x 15467 shillings and 2 pence per ton=£3-7-2. Cuap. XXIV.|] vVaLUATION OF MANGANESE-ORES. 495 In order that an ore should be subject to the application of the scale of prices given in table 27 on page 415 it was formerly necessary that it should not contain more than 10% of silica and 0°10% of phos- phorus. [These rates may be considered as those applied to ore delivered in the United Kingdom. ] In the United States, according to the * Mineral Industry ’ for 1905, : _ published in 1906, the schedule is fixed by the cia ees Carnegie Steel Company. The ore must not ' contain more than 0°1% of phosphorus, nor over 8% of silica ; deductions are made from the price of the ore of 15c. per ton for each 1% of silica in excess of 8% and of lc. per unit of manganese for each 0°02% of phosphorus in excess of 0°1%. The price per unit of manganese given in this publication is as follows :— Over 49°% of Mn. af 28 cents. 46—49% of Mn. ye tity anata 43—46% of Mn. ae O60. 40—43°% of Mn. 25) "55 Ore containing less than 40° of manganese, or phosphorus or silics in excess of the above limits, is sometimes subject to acceptance or refusal at the buyer’s option. An additional price per unit of iron present in the ore is sometimes paid by the steel-makers ; but the practice as regards this constituent varies. In the ‘ Mineral Industry’ for 1903, issued in 1904, where the price per unit of manganese for ores containing over 49% of this constituent is given as 25c., the price paid by the Carnegie Steel Company for each unit of iron is given as 5c. Owing, however, to the rise in prices during 1906, and the great difficul- ties steel-makers are said to have encountered during this year in obtaining the full amounts of ore required, there seems to be a tendency for a slacken- ing in the stringency of the requirements of the steel-makers, especially as regards manganese and phosphorus contents. It is probable that a consi- derable proportion of these restrictions are not always closely connected with any metallurgical difficulties in the treatment of the ores, but with the desire of the steel-makers to obtain their supplies of manganese-ore at as favourable a price as possible, and to be able to cut down the prices paid whenever possible by levying fines for the presence of a small per- centage of a given constituent in excess of what is stated in their schedule of prices. That this is probably the true interpretation of the situation is shown by the fact that during 1906, under the influence of the great Requirements made less stringent during 1906. 496 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part III: demand for Indian ores, it seems to have been possible to find a market for almost every variety of ore that could be obtained, except the very siliceous ones. There has for some years been a steady demand for the ores of Vizagapatam, ranging in phosphorus from 0°25 to 0°45, and for the Jhabua ores averaging 0°20% of phosphorus. During 1905 and 1906 a market was also found for Vizagapatam ores containing between 30 and 40% of manganese ; and I understand that during 1907 some of the ores from Shimoga in Mysore for which a market was found ran as low as 30% in manganese. The constituent that seems to be of much more importance than the phosphorus as a deleterious constituent is the silica and I do not know of any cases of contracts made for the supply of Indian manganese-ores containing over 10% of this constituent. According to John Birkinbine! the requirements of the steel manu- facturers, particularly with regard to the permissible phosphorus, were altered in a schedule issued in the latter part of December 1905. This schedule applies to the Carnegie Steel Company and the Illinois Steel Company. ‘ Prices are placed on ores delivered in the Pittsburg, Pa., and Chicago, Ill., dis- tricts, per long ton, containing not more than 8 per cent silica and not more than 0°25 per cent phosphorus, and are subject to deductions as follows: ‘For each 1 per cent in excess of 8 per cent silica there shall be a deduction of 15 cents per ton, fractions in proportion ; for each 0-02 per cent or fraction thereof in excess of 0:25 per cent phosphorus there shall be a deduction of 2 cents per unit of manganese per ton. Prices per unit. Iron. Manganese. Metallic manganese-ore containing above— Cents. Cents. 49 per cent. r A = ‘ - 6 | 30 46 to 49 per cent. ; 5 - 4 6 | 29 43 to 46 per cent. é . : ; 6 28 40 to 43 per cent. - - : : 6 27 * + Mineral Resources of the United States’ for 19%, published in 1906. led Cuap. XXIV.] VALUATION OF MANGANESE-ORES. 49% ‘ Norz.—Ore containing less than 40 per cent manganese or more than 12’ per cent silica or 0-27 per cent phosphorus, subject to acceptance or refusal, buyer’s option. © Settlements are based on analysis of sample dried at 212°F., the percentage of moisture in the sample as taken being deducted from the weight. ‘ Prices subject to change without notice, unless otherwise specially agreed upon.’ The Indian ores containing in excess of 0°27 per cent. of phosphorus are those of Vizagapatam. These are sent to the Continent, where they are said to be used in smelting the minette ores of Luxemburg and Lorraine, being mixed with the iron ores in the blast-furnace burden in order to produce a pig low in sulphur, but high in manganese and phosphorus, for use in the basic Bessemer process of steel manufacture. Use of the Vizagapatam ores. As there are in many parts of the world manganese-ores that do not come within the limits of the schedules for the purchase of manganese-ores, it is often necessary to arrange special prices to suit special cases. Thus, according to the ‘Mineral Industry’ for 1905: Special prices. - © Russian ore of ordinary grades, during the five years 1898—1902, sold at an average price of $11:54 per ton. More recently, however, prices, particularly of high-grade ore, have advanced strongly. The price is based on 50 per cent. man- ganese, with phosphorus not to exceed 0°17 per cent., nor silica9 percent. Samples are dried at 100°C., and humidity is deducted. Such ore sells at European ports for 16 to 28c. per unit of manganese ; from 5 to 10c. per ton is deducted for each per cent. of silica. ‘On Turkish ore, the base is 45 per cent. manganese, with limits of 0:03 for phos- phorus and 11 per cent. for silica. * Japanese brown ore sells at Hamburg at from $12 per ton for 65 per cent. MnOz ore (41 per cent. Mn.) to $27:60 for 87 per cent. MnOz ore (55 per cent. Mn.) * For German ore, the price is calculated on a basis of 50 per cent. MnOg at $4-80 per ton, with an increase of 24c. for each unit of dioxide above 50. “French ore, calcined, with 35 to 40 per cent. manganese, in 1904 brought 30c. per unit.’ The prices noticed in the preceding pages are those obtaining for manganese-ores destined for use in the iron ane Leda oe and steel industry. For chemical purposes, however, it is not the percentage of manga- nese that is of importance, but the oxygen in the form of peroxide of manganese, MnOos, this oxygen being known as available oxygen, , be- cause it can be liberated from the ore on treating it with acid. The prices obtained for ores fitted for chemical purposes are often much 498 MANGANESE DEPOSITS OF INDIA: economics. [Parr IT1: higher than those given above for ores used for the iron and steel industry. This question I have discussed in the chapter on the uses of manganese, where (page 599) the prices will be found, as well as the points that have to be taken into account in valuing an ore for chemical pur- poses. It will be interesting to discuss the question of the nomenclature of Nomenclature of man- Manganese-ores for commercial purposes, deal- ganese-ores and mangani- jing only with those used in the metallurgical ferous iron-ores. . : industry ; for these form by far the larger pro- portion of the whole. Itis customary todivide the ores containing manganese into manganese-ores proper, and manganiferous wion- ores. There is every gradation in composition between iron-ores practically free from manganese, through iron-ores containing larger and larger quantities of manganese, to manganese-ores containing large quantities of iron, and from these, through manganese-ores con- taining smaller and smaller quantities of iron, to manganese-ores practically free from this constituent. All these grades of ore are of use in the iron and steel industry. It is customary to divide them into iron-ores, manganiferous iron-ores, and manganese-ores. The dif_i- culty is to decide what is the minimum percentage of manganese inan iron-ore that shall necessitate the prefixing of the adjective ‘ manganiferous ’, and what is the minimum percentage cf man- ganese that shall necessitate calling an ore * manganese-ore’ instead of ‘ manganiferous iron-ore’. I understand that the least percentage of manganese in an iron-ore that is usually paid for is 8%. And it hardly seems necessary to call an iron-ore ‘ manganiferous iron-ore ° if it contain a smaller percentage of manganese than 5. It was formerly the custom in the United States to call an ore a manganiferous iron-ore if it contained less than 449% manganese (equivalent to 70% MnOg). Later, ores with as little as 4094 Mn have been termed manganese-ores, and those below this limit manganiferous iron-ores. According to this method one often sees an ore referred to as a manganiferous iron-ore that contains more manganese than iron. This seems to me to be irrational!, and easily to be avoided by creating a class of ferruginous manganese-ores. Suppose the total of manganese plus iron in the ores of Ferruginous manganese- ores. 1 The commercial nomenclature arises from the buyers and sellers calling manganese- ore all ore from which rich ferro-manganese alloys can be made, and mang in ferous iron-ore such ores as are Suitable for making low grade ferro-manganese, and _ spiegel- eisen. Cnar. XXIV.] NoMENCLATURE OF MANGANESE-OBES. 499 a given area to be usually somewhere about 60%. Then the following classification would seem to be a rational one :— aa _ Mn. per cent. Fe per cent. Manganese-ores : ; : - - | 45-60 0-15 Ferruginous manganese-ores_ . : : 30-45 15-30 Manganiferous iron-ores . : : - 15-30 30-45 lron-ores : ¢ = - - sel 0-15 45-60 Although the sum of the Mn and Fe in the ores of the Central Provinces is usually nearly 60°, yet there are many cases where the sum of these two constituents is considerably less than this amount. A reference to the table on page 512 will show that the sum of these two constituents in the average ore of different areas in India varies from 46°77 (Singh- bhum) to 59°80% (Chhindwara). For ores in which the sum amounts to 52% the nomenclature would be as fol:ows :— ———— Mn. per cent. | Fe per cent. s pe hl ve al wee pe is SS | Manganese-ores - - ; : : 3 £- 52 | 0-13 Ferruginous manganese-ores. : : 2€-3 9 | 13-26 Manganiferous iron-ores . : : : 13-26 26-39 Iron-ores . : : : : : 0-13 39-52 Similar sets of figures could be drawn up for any other value of Mn + Fe, by dividing the Mn and Fe percentages into four equal sections. In the tables of analyses of Indian ores given on pages 501 to 513, I have used this principle in classifying the ores, extending, however, the class of manganiferous iron-ores in accordance with the next paragraph. For commercial purposes, however, one table for all ores woald pro- bably be considered desirable. Hence to allow for the facts, (1) that ores 500 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Parr TI: from different sources show a different average value for Mn+Fe, and (2) that iron-ores. containing 5 to 15°94 Mn, which in the fore going classifications would be designated iron-ores without any qualify- ing adjective, would yet command a special price on account of the manganese present, and (3) that ores containing more than 10 °% iron or possibly more than 8 %) had better be classed az ferruginous manga- nese-ores, and (4) that some iron-ores give nearly 70 % Fe. on bulk analyses, I propose the following, ’or something very close to it, as a more rational classification than the one at present in use :— Ne TE OAS CAC: CAN sates Mn. per cent. Fe per cent. Manganese-ores : . : . : 40-63 0-10 Ferruginous manganese-ores’. - : 25-50 10-30 Manganiferous iron-ores . F 3 s 5-30 30-65 Tron-ores 3 : - : : 5 0-5 45-70 This table is applicable to all ores with over 50 % of Mn+Fe. It will also be found to apply to many with less than 50 % of Mn+Fe. For ores with Ma+Fe less than 50 it would be easy to construct another table. The classification of ores in this way is roughly conformable with the product to be manufactured from each. The four divisions ccrres- pond roughly to higher grade ferro-manganese, low-grade ferro-manga- nese, spiegel-eisen, and pig-iron. Analyses of Indian Manganese-ores. In the following tables I group together for convenient reference the analyses that have been made of bulk samples collected by myself either from the outcrops, or from the ore-stacks, of the different Indian manganese-ore deposits. In cases where I have not taken samples I give analyses kindly supplied to me by the companies or individuals working the deposits. These analyses are also scattered throughout the text of the descriptive portion of this Memoir under the headings of the respective deposits. A Tables of analyses. Cuap. XXIV.] ANALYSES. 501 few of the analyses represent hand-specimens ; whenever this is the case it is so stated. TABLE 55. Analyses of manganese-ores and manganiferous iron-ores from Singhbhum, Bengal.' I lity |Matkam- Matkam-| Tekra- Bistam- Tekra- | Tekra- Tekra- HOEAUy | hatu, hatu, | sai. Gitilpi. | Gitilpi. pur. | sai2 | sai.2 | sai.2 | eo etre abl ral = =a Psilo- Manga- | yy melane niferous | Manga- | ee Nature of the | and limon- | Psilo- niferous Psilo- with Psilo- Psilo- _ Psilo- ore, limon- ite and | melane, limon- melane, pyro- melane. melane. melane. ite. hema- ite. lusite. | tite. | Number :f ‘ | er | | : ; sampl, ‘AS obr |PAL, 37 A. 38 A. 34 A 35 A. 38 A. 380 | A. 381 | J. 917 Manganese . | 20°66 | 4°23 | 48°08 10°62 | 48°01 | 46°89 | 50°66 | 55°61 | 57-14 Iron . . | 25°60 | 41°30 1°22 | 38:00 | 6°10 1°37 Silica . | 16°58 | 18710 | | 8 Phosphorus . 0°701 1177 | 07416 Moisture . | 1°00 4005 10 TABLE 56. Analyses of manganese-ores from the Panch Mahdls, Bombay.! Locality. i Sivar4jpur. ee - a a = Number of sample. A. 44 A. 45 A.4 A. 47 A. 607 | Se a i | Manganese. , ; 4 38°77 48°41 49°35 | 30°20 51°40 tron ; : : ‘ 3°40 3°60 6°25 305 | 4°20 Silica p + . ef 25°80 7°20 2°80 | 40°65 6°90 Phosphorus . 4 F 0°223 07158 0°253 07174 | 0°160 Moisture : 5 c oy 0°30 0°25 0°35 0°40 0°60 1 By Messrs. J. & H. S. Pattinson, of Newcastle-on-Tyne, ? Analyses of hand-specimens, not samples, 502 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [ParrIII: TABLE 57. Analyses of manganese-ores trom the Satara District , Bombay.’ Locality. Lingméla, | Bhekowli. Chikhli, | Yeruli. Number of sample. ; A. aed A. 50 A. a vr eee JJ hess = asereeAlhs S : Manganese. 9c) (4.0 toe 37°58 41°89 | 45°62 38°08 fron. ‘ : . ‘ : 9°25 4°40 | 5:00 9°10 Silica . : c ; : ans 3°45 2°90 | 3°90 4°75 Phosphorus . ‘ 4 : 0°036 0072 | 0°060 | 0°098 Mottaret ee ink | © ae LT Fane | 4-70 | 1°75 TABLE D8. Analyses of manganese-ores from Jhdbua State, Central India.' Locality. K4jlidongri. | Rambh4pur. : 5 Number of Sample. | A. 39 | A. 40 Bo AV ine Wie Bi AD ce | A seh A. 467 Manganese . . . | 47°77 =| 48°40 | 48-25 | 44-29 | 45-92 | 50-02 Iron - + + | 8°60 | 10-40 -| 9-45 | 7°90 | 5°86 | 6°75, Silica ; 5 eo) OCD. | Seg | 8°60 | 5°85 aes 5°60 | | Phosphorus , . | 0°165 | 0°24 | 0-27 | 0-18 0°17 | 0°05 Moisture . . .| 0°20 | 0*20 | 0-45 | 0-75 | 0°55 | 020 1 By Measrs. J. & H. S. Pattinson of Newcastle-on-Tyne. 2 Analyses of hand-specimeng, not samples. KAjlidongri.2 lee 505 | ee | 58°53 57°85 3°30 3°00 4°25 | 8°70 0°06 | 0°07 0°20 0°40 “odes v 4ou ‘Mouloods-pury g Dr) MOST} "§ “HY ‘fc SIssoW AT ie aa | B | i=- G 5 5 =] =} < : m BASES 8, = 5 5 bP) | ae 8 Si g gs FE] *AN[BOOT BR | ae "hl ves I= 08 oi) | 7 ie at 3 2 3 * oak oF ° o 5 : { | =} eae ay 5. = 5 . saounnong jouuay ‘prysrip wybypg ay, wor saso-asaunbunu fo sashjvuy ‘6G ATA], 504 TABLE 61. MANGANESE DEPOSITS OF INDIA: Economics. [Part III: Analyses of manganese-ores from the Chhindwdra district, Central Provinces.' | é al ees a ole 3 £ S a 5 g 8 paemies® ae eee ; ; A 2 2 |e = 5 =| gs & : & |-ai| A bese 3 FI a es 2 & SSDEpM I a ye 3a i eee eee eee amps) 2) ss s S| Ss B ay a S reagan eae Number of sample. 9 11 | 12 10 10A 13 14 8 7 | 797 752 | ale | Manganese . 54°73 50°41) 54°98 54°97] 54°57) 48°95) 49°55) 29°08 53°59 54°60 55°94 Jron . 5°00 11°77) 6°19 6°89! 7°03) 7°03] 7°71) 6°88) 5°00; 4°69 98°44 Silica . . | 6°99 4°86) 10°63 6°95| 7°90) 4°98] 8°74] 36°68 onal Sb TT Phosphorus 0°07, 0°20; 0°04) 0°06} 0°12} 0°28) 0°28) 0°15) 0°07; 0°01 0°03 Moisture 0°17 0°39] 0°32) 0°00] 0°04; 1°27] 0°52} 0°86] 0°31) 0°09 o-07 DE ET 1 By the Imperial Institute, Londen. 2 Hand-specimen, not a sample. % Hand-specime, not a sample. By Messrs. J. & H. S. Pattinson. By the Imperial Institute. 505 ANALYSES. Cuar. XXIV.] *910 JO soigiquend oie] quosoides Ay, eqvolpudg Supjoadsoig svoUlAord [e1qUaN oY J° JosvurW “AIelO “A “AM “IW Aq polddns A[pury (p) ‘dopu TJ ‘e4yngysuy [ebodury on} AT 1 i | { { | _ eee ob ez.0 | 8.0 | tz-0 | eo | ze.z | $9.0 | 9.0 | g¢.6 | OL. | 67.0 | 69.0 | ¢9.0 | 86.0 | 06.0 |M2z-0_ |." ~~ omgstoly ¢0.0 ; F1.0 #0.0 90.0 60.0 81.0 ST.0 60.0 | IL.0 60-0 | 80.0 | 020.0 80.0 40.0 | 60.0 * snioydsoyd eg.9 | 00.6 | zo.ot| sr.et| ¢%.¢. | 06.2 | 66.9 | Te.g | 88.8 | 09.¢ | 84.9 | 96.¢ | €6.4 | THF | STG | ~ ~*~ OMS gz.¢ | os. | ze.6 | 60.c | o2r.¢ | se.0r| 2¢.8 | 9z-0r]| 14.9 | Te.9 | g¢.2 | 6.2 | 09.4 | 03-2 | 2-9 | °° oly 6.e9 | 12.59 | 9z.2b| 8.8h | 82.09 | 2.97 | @F.TS | ST.6F | 08-2F | IT.IS | 9z.TS | 4.09} 82.29 | £2-6F | 20.TS | asousueye Se | a | ire ee a |e a ee | ee i) _————— [a a &% IZ gt 91 eI 98 eg #8 8 ze | 18 og 6z | 82 14g adres yo 1aquinny | —— |} —— ~-—~— —— = —— - —_—- oo, So Q ' as) Ss | <= & Z E 5 = S & S es a S ry ry s al So © 5 5 are) a me | ogg | 5 =| 3 =I | ic =e ae ae wo & a Ve e | = Ei = w s 3 & | *AytTe00'T o> a. os | = = | > | = Ee e A z 5 =| i} =f = S 5 8 © sl 8 5 S = # ) ° . | | : = | Los o— : 88.0 | 21-1 | 91.0 | 11-0 | 09.0 s ub abe ++ { g9.0 | 98.0 | 98.0 | 26.0 | @e.0 | 82-0 | * * emsIOW | | 90-0 | 90.0 | 990.0 | $9.0 | zt.o0 | 60.0 | ¢0.0 | 20.0 | 60.0 | ¢t.0 | 90.0 | of.o | 80-0 | @I-0 | of-0 * smoydsoud | | | og.F | 80.9 | 69.9 | 86.8 | s2.9f| 62.6 | 46-9 | ST-8 | 44.8 | 90-2 | 9.9 | 80-9 | Zh. | Lh-F | 80.7 | © * ROTTS | | | yc | oeo.¢ | 88.6 | 22.8 | 20.9 “3 zee | 62.6 | v8 | 00-2 | 10.9 | z6.¢ | 22.8 s99.9 | 09.2 | ° ” worl 9z.ro | IT.6S) 28.29 / GI.s¢ | 22.29 | 00.49 | £6.59 | 96.59 | 9.99 | Te-TE | LT.9] 40.69 | FERS 0.89) FE.zo ” esoURSUe]Y [eed Nach (es eee ee | eer | ee | ed a ae ae a ee 9% dg || ize 0z 6I D D D Dopo iis f ¢ Zz T _-ajdures yo Joquinyy o re cp ae S. So eo et eee |) 5 B al g a e et mR g BO ee sew See th ae F E E Z E E E 2 a 3 8 7 |) eee 8 8 5 cy 5 ae ee 5 S | & * Le007y R q | 2 n : ' Sa ee 5 5 Seatac: 7 a | ae 3 3 (ees | ' | | 5 | s | o - | pseunorg jouay youjsrp indbp x ay, mor; aso-osaunbuvw fo sajdwuos Jo soshjpup Il ‘G9. HAV, 506 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part III: | | young, a] | oO ie) a 4 TUEMeUNE 2 i) a rc) a ¢ a ap pus SepewoH 9" = io x x ° ° ‘/ 307 pee (a Sip i sx cx i Se \ Stee eS Wed ~oyIsnpoIAg S : $ 3 : : a 4 |he= = i oe) Ne} 19 i eS AUS ‘Ss “oyopynsny oULTOULOTIST = r = 2 SI > bol = Len o 9S = ar AY “pea pur auejoul eS rst m 19 9 19 = -oyoprnany -opisd ‘(2) 0919 6 a a or) 3S 1S 3S -oUSvULUeSURTL 4 a a —) r=) ° ~ | =~ N ~ ! _ 5 — == An ——— =* = = t LY SoS o 1D S 3 =) i) ‘Tygareppyy, | “Testo ot mag | & B % g eS 2 = Sl S Co) oe) ) i) ~— S _— 2 : eS ‘'~ S “S ana oe) bel bs + a icy oe TYRMILIR “OUST g ~ = 3S a oO S % pur ayraneig S oo os to S S itn} S = oo ~ = > } 19 a oO bed S “"BUOPyOT ‘ouvomonel a) 1) cee en I 2 puv aytuneig = © & = S Sy S | nN o> ia > [o') = “TIsUOplEg “apIDINQuaepelA eS © ri ~ a 4 s = | cd | Ht i=} onl oO Oo eo § [eee on 5 = — ae Me ; — = ~ & — a a oD boil oO a = = e “LsuOpleg ‘oysuoppg | 5 = a el S cS isa S a g 19 S r) a g | | 1 , 19 | 19 rt Re} & “puyy suvjetorisd | g 16 3 % S = ae pue oytuneig | % a cs SS : SS = LS = LE = S : es RS e “apa imma | 2 | 8 og g ag @g — apr pur oymmerig an : : S : Se cs] i") ° o D = a 2 |- SF ee =4% = 2 a | for} oO “f @ Lae} iO => “upUey Onn SH. Bote 0 eh peta wees s pue orang, ix = 3 ee be! eo ar ; —S == a 3 | ‘ : > a S q © a 2 we a D 3 a=] oo r= | v 8 © 3 | qs & P| q i=) pA! oO s , =| o 3 Bo op 2 5 4 s ya | 8 =| S) B Q e i s g tl a g i | a] - nM 4 al ANALYSES. Cuap. XXIV. | ‘(81 "V—9 *V ‘son) WOsuI}}Cd'S “H PUL "f “SIssoJT pue ‘(69—gg *sON) 0yNgGySUT [eed oyy Aq sossjeay | 09.0 Gt-0 | #€.0 6&.0 | | 70-0 | 8.0 | o%-0 | ae.o. | gg.0 | 20-0 | Gst.0 | 2.0 | 62-0 | cet.o | 90.0 | €0.0 | | 08-9 | OF.0¢ | 89-01 14-G | OLS | 62.6 9.61 | OF.F ¢8.11 0-21 | OF.Ez | 64-% | | | | 06-69 | 06. gf 80.¢F et. i¢ OL. Lt L1.93 OL.#2 | LF. 1E 06.9% #9.92 LT.61 LE.G | | | | | 91.0 OL.1 {2.0 6¢-1 | 02.9 | 16.91 8.22 | 00.6% | 09.9% G9.F2 | F1.ce | e9.48 OV | ay 29 *9 8'V 69 LUV 9 9v 89 | 99 19 SS Ras oe. il % Ye ess ee | | | | “oue] *(910-980U | -ouroyisd -eSUeUL | ‘ouRTauL pur 0919 ond | | snoul3 “ayy | ‘optget | -OTTSd yo| aytsnq | ‘ogyuoury -euloy | -Ruley (*‘oqyruoUny Scare ‘outs -nijoeq) -eulay | “a SNo | SJouI9A | -o1fd Jo} snoro0y SOIT SnOey | pur oqis a a - ao | e[bys “‘pRAL “OOBOTIT | TITAN O91 |sqsou pree|*luesuey) -aesarypy -luesuRyW| -njorIdg I i | SnoJley “UOT | sutoa | -luesueul YGIM 991 | /pux oury | “WOW T -OULOISd - ee ie Z 4 Mick ¥ 1 3 iz . | "eyo! ; ‘ van 1H ‘ ‘ “wind “el Mic) PON elle ‘mop Wet) -ueyy WARS -Yesueyy| mysey NABS -WeIeyd| -Yesuey| -uepy | -oryqeg | NABS -By9ud *(snosoyluesueut A] 481s) $010-U01T “8010-UOdT SNOJO;.U CSUR, SAQUMOL ‘ind | -[es0p 8l'¥ *eUe] -OulOyIsd “wind -UlRIVyd *s010-9800RSTB SS SSS nr “OINYSIOW gs snzoydsoyg volIS uo] esouvsueyy a[dures JO Joquinyy “910 844 JO 104 ~OBIBYO [BOISO]RIOTIYY “AqIpBo0"} “a10 JO sseIp 1p.qMay “rysyp ndyoqn pf 24) Woxf ‘saso-Wo0.d pup ‘saLo-uow snosafrunbunu ‘saso-asaunbunu fo soshjpup ‘79 ATAV I, Til . ° Economics. [Part III . MANGANESE DEPOSITS OF INDIA *00¢ odvd uo posodoid ornye[ouswOU OYy 04 Zurpiodgse *,se1o0-osouUvTUBUL SHOULDNT , « “UOsulyyed “S “H pure “f¢ ‘sissoy Ag 1 60.4% OL-0 c¢.1 cE.F 0z.0 0€.0 6z.0 cZ-0 0Z-0 3-0 . . OINysloyy 9Fs-0 cog. 0 980-0 FIL-O F1T.0 12-0 L1t-0 $20.0 Z10-0 160-0 * snaoydsoud cF-.0 00.6 66.01 OF-€ OL-F 00.2@ 0¢-.0 1.8 | 02-0 cZ-8 é fl * BoTTls 00. OL-@L cP. O1l-F 02-6 09. ¢0-.0 OL-OL 06.12 06-6 . 3 ji uoly 8L.6P 19. &F 66. 6§ 6¢.1F 0S. 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LF £6. 9F gSoULSULIY , ; ; | 4 sore Pie . “ayd 93° V « 96°V *43°V *Z6°V | «02°V “06'V 12 V | «18'V 66° V 08° V LOW | 83° V¥ -Tues JO JaquinN a0 \S0s'.) et Mees | at 4 a ae * | | “BSTBA yd | | “ule -nhinyueg | - prey ‘ureinduog) | -indepue | ‘epgaed ‘Inpoy *IPIALIVy . . . . | . -uepue | WpnsvAay) VLIVYCIOH | Upyqiny | “wyqqiey | 1dvi9dg pues | Shanes a = gh eo cet | ~ v = “WVUNIVUCVHAVAV YL | | *SANIW UNGOY aH a rs rspupp yy qousyp unpdvbo2, ay) Worf saso-asounbunu snourbnasaf pun sa.o-asounbuou fo sadwuns fo sashjouy ‘Gg W1dv Cuap. XXIV. ANALYSES. 509 TABLE 67. Average analyses of the manganese-ores! of the Vizagapatam district, Madras, as supplied by the Vizianagram Mining Company. ! r arividi mare Sandananda- Itakerla- Locality. Sa Perapi. pilli. |Garbh4am. Avagudem.| Garuja. a a SS ; ——— } Manganese . 43°02 | 49°69 48°14 41°63 43°00 | 45°39 42°41 | 41°45 jIron . . | 10°02 7°41 2°35 11°52 8°74 | 9°99 12°90 | 11-70 = | | Silica . i} 5°03 3°20 3°05 4°30 5°70 4°43 3°85 | 3°63 | Phosphorus .! 0°259 0-297 0°262 0°286 ae 07450 0°375 | 0°298 } | | TABLE 68. Average analyses of the ferruginous manganese-ores* of the Vizagapatam district, as supplied by the Vizianagram Mining Company. Locality. | Perapi. | Garbh4m. Avagudem.|Aitemvalsa, Bondapilli.. Garuja. pps | Manganese . . 36°17 | 35°43 35°75 35°77 38°48 38°51 37°11 | | | | | | } Tron . - = 15°69 19°32 | 16°89 12°87 14°22 13°20 14°22 | | | Silica lene |. 5°40 6°90 5°95 ee 4°93. | 5°50 5°65, | Phosphoru:. . 0°204 0°423 0°439 0°222 0°332 0°269 0°455 | | It will be convenient to summarize the figures given in the foregoing tables. In table 691 have given the range, and Summary of tables in table 70 the mean, of the various consti tu- of analyses. : : ents of the ores of each area as given in the tables on the preceding pages. The Belgaum, Dharwar, Sandur, and Mysore, figures I have summarized from analyses kindly supplied by the firms concerned, but not reproduced in detail here. 1 They include some ferruginous manganese-ores. 2 Designated manganifercus non-ores by the Vizianagram Mining Compaay. [Parr III ECONOMICS. MANGANESE DEPOSITS OF INDIA DLO 4Z-1 —00-0 82-0 —90.0 9.01—86.F ZL.11—00.9 16.4 9—6.8F 00.£ —60.0 | ¢8-0 ——0Z.08) 8F-88—SF.61 $8.21 —FE-8 | OFT —00-T | 88.0 —ee.0 ZL-0 —10.0 | 8T-1 —¢¢.0 | 24-0 26.0 | 0.3 —99.0 | OL-8I—OL-FI 0&8 —€F-2 | 8&-8I—01-0 | 08. 1509.0, 01-9 — 22-1 $8.09—02. 18) 99-06—EZ.F | 80-8F—68.9F “910 -aSouRsuURyy ‘VUYLYS t ot z ot | g g ‘10 | Lesousituwar |“ax0-tost sno (MEE SuIOB)) —— CaTO, ‘210 ~osouRsueN snoulsnaua 7 pe AC NN -osoURsUNN ~JoyluvsuEyy Be egal oe ee phayvetag ‘WOHAHONIS “AVANO “TVONGA * aanqstoyy *snsoydsoyg * osouvsuviy ‘sosApvun yO Jequiny ‘al0 JO ssvio “\LOIMLSIG “HONTAOUd ‘Dipuy fo santraosd pun sporagsrp quasafjrp ay)? wou sa1o-wor snowafrunbunu pun s2.10-asounbunu fo sashjnun fo abuny “69 BTA I, 511 ANALYSES. Hap. XXIV.] 1 4 ( “mOsMeg “Wf *V ssty Aq porddns ‘s}stueyo snorea Aq ‘sosdjeur wo ¢ “qqloued “g "9 “IT Aq soInay poyeulysa g “qaeqny *O “IW Aq ponddns ‘sesArvur woiy ; ) | | es [ gnoqe T ynoqe | re ae | ¢8.T —0¢.0 cf, C6.6 8€-0 —6z-0 ¢9-0 —ZI-0 | 06.0 —6E.0 | ZE.1 —TT.O | * oINgstoyy | | ¥I-0 —10.0 | 90.0—10.0] 90:0—ST-0} ¢¥.0 —0Z-0 | o.0 —9z.0 | 8F-0 —€1-0 | 80-0 —Z0-0 | 12.0 | 8F.0 —F0.0 | $8.0 —Z0-0 | 9%-0.—£0-0 | ¢9.0 —F0.0 |snsoydsoud | | | | ¢L.G —2z.0 9—<4 €—T | 06-9 —€6. | 04-4 —GO0-€ | 0€-01--OT.T | 00.1 —€F-0 | ¢Z.0T | OF.0Z—Tz.¢ | OF-E3—OF-F | 6L-— —OF-I | SF-81—06.4 | ° volts | | | $¢.4I—10.F | 0z—OT OI—G | - ZE.61—28.21| 06-ZI—GE-Z | OL-GI—08.F OF-6I—8E- | OL-6T | 06-6¢—80.cF OT-LF—LI-6T| O-01—09.1 | F&-91—60-2 | * ui] | ¥6.SS—TS.48] +¥—08 9S—FPh | 1g.8E—€F.SE| 69.6F—SF-1F| G0-6F—T2.2E 6E.F9—LF.6&| FF-82 | 04-1 —9T.O | 09.¢c—0z-9 | 08-9S—ES-F&) GE.99—8G.GF| esouvsuLyy | | | “SosA[vue 6 J) i 8 ZI 9 mY t L € 0g yo | JaqwuuN ——————— | | = eal ae = =. ae Ss Es “310 (snom | *910 | “o10 “210 -asoueSu eur Bet ‘oped | -osourSueut | “910 | -osourSueur -esetedueut | -a10-asou | snoulsniJey oe fi IaystTH | snoursnise,g | -asoursueyy AX SNOUTSNIIoF snoulsniiey | -esueor EFOMIGR *910-TO1I SNO *g10 “310 | “310 E@) ets | pl 8 a10 pue 910 snou Ee q -loyluesueyy | -osouesuryy | -asoursueyy Jo ssvQ ~osomedue yy | | | -osoursuryy -asoueSuryy | -1snas9y *910-as0uRsUR]y “Aueduiog Sumi | tmeiseueiztA Aq peyddng 2 Aueduo, z ll mi | odeiashe : ey aso ; eBourys “083.8 SIOSATY MON —— “WVLVdVOVZIA | ,UMaNVY |WYLNVH "aNd TVaVe *andDYN TLOMMISIG “YOONIHS ) =— Se ee —— | mut 4 | “*HONTA “HUMOSAW “SVUGVA “pjv0I— SAO NTAOUd TVULNGAD .-OWd “‘pyuwoa—GQ AAV J, economics. [Part III MANGANESE DEPOSITS OF INDIA d12 LLL | OF-19 40.69 98.09 LLL 08-69 13-69 82.69 88-99 EL-Lb 9L.9P GE-BP 80-09 OL-o¢ j44°0F 99-09 | ° oly | + osouvsuvyT £80 18.0 99.0 86F-0 88-0 PPO 18-0 SP-0 66-1 8-0 ne a s* jLT-T 189-0 * 9ngstowt Gb.0 3-0 S130 11-0 P1-0 PLO | [L-0 02-0 40-0 0z-0 B £20-0 80.0 ‘¥L.0 8-0 *snioydsoyg 9401 | 66.21 | 89.3 OBL OL 69-8 PLB 1-8 G18 11-61 L61 LGB | OFT |OFOL 89-F BOILIS 09.09 84.83 62-6 $863.9 | KO'L LBL | OF PF-8 ¥6.9 10. 8.91 | So 6F | 88-01 [86-78 |06-2 ' uol1y | | 96-0 92.0% 99.9 £4.19 2L.29 £6.19 88.19 ¥6-9F 61-06 89.1P 29-1 | SPOT) LL-bF PB1T 99-26 | * osouvsunyy aot — | es | - el 4 ——— ~ _ | | *Sosd[vue ¥ ZL g 0g 8 81 | ST ] ¥ p or 3 or | 8 8 jo soquiny | | oe = ———— = ————-] — ——|} ———. by 2 wo] ah] 6 | Ue | ae) ES) eB OF 5 3 3 g5 3 i “010 “940 | ‘0x0 ‘010 ‘010 “010 “910 g re) S36 | 5 = 33 - : #3 | i 8 -osounsunyy] SSoUsUnyy -osoULT UL py)-OSPUUTUL}Y -OSsoUvsIY A -osouvsunyy/-osouvsuer) 5 re. Ee Poe S e a10 Jo Ssvid 3 5 E I 2 | snoujsnieg) S| 2) FTE o 4 aa oO Dot 7] ' ‘7 U ae Sait a = = Ba Seis, : : |- ne a , : ‘vuyM |. . . : “STYHVWW | “(ITONYS) “ry ‘HOHAHONIG | “LOUIS! wndivave WAddyN ean VUVONVAG) \“tyHpytyg) “Vadyur vuy Lys HONVG | UYAUYHC | WaoTIg | Wa 8 ith ‘SHONTAOWA TWHENLO | avian “AVANOW | “IVONEG | ‘ONTAOWd a “pypuy fo saouraord pun sprysyp snoruna ay) Worf saso-wou sno.efrunbunu pun saio-asounbunu fo sashynun fo unayy ‘OL LIAVL, Cuap. XXIV. ] PROVINCE. ANALYSES. TABLE 70—conid. on ee ee ee ee ee ee MADRAS. MYSORE, 513 DIstTRicr, | GansAm. SANDUR. VIZAGAPATAM, Class of ore, Number of analyses, Manganese . Tron Silica . Phosphorus, Moisture Manganese + Tron SHIMOGA. New Mysore Ma - | Shimoga | os Co. ngon Meneesucse | Suppliedby Viziana- Ferruginous 7 | gram Mining Co. manganese-ore. Ferrugin- Ferrugin-| Ferrugin- ae FTES |) 2 ous Man-|OUsS Man-} ous Man- Ferrugi- Manganese gahese- | ganese- jganese-ore. |Manganese-|nous man Higher Lower ore. ore. ore, ore, ganes e- grade, grade. ore. 1 6 12 | Half the S U 3 | timits. 9 28°44 47°75 42°96 44°34 36°75 46°75 37 49°10 19°70 11°45 11°22 9°08 15°20 10°06 15 7°74 | | 10°25 0°61 4°29 4°15 5728 stiden | 4 2°62 | 0°71 | 0030 0°27 0°32 0°335 003i | 0°035 0°085 | 2°56 | 0°90 : 0°95 1 — — — | | | 48°14 | 59°20 54°18 53°42 51°95 56:81 | 52 56°84 For comparison with the figures given in table 69 I give below in table 71 figures, obtained trom a reliable source, show- Analyses of Indian ores expected _by buyers. profitable to work. ing the range in the composition of the ores that buyers expect to obtain when contracting for the purchase of various Indian ores. It will be seen that they agree very well, with one or two exceptions, with my figures given in table 69. The most marked exception is the Panch Mahals. My figures are probably lower than would be obtained in practice, because I took average samples from the outcrop without any selection, such as would naturally take place when the ores came to be worked. Some of these samples are, moreover, probably from parts of the outcrop that it has not been found Economics. [Parr Til MANGANESE DEPOSITS OF INDIA 514 £0-0—#0-0 | §€.0—92-0 90-0—¢0.0 | PLO—I1.0 i—¢ t¢ 72 | 8-9 OI—6 FI—Z1 9I—s— | 9—3 L¥—9F Li—St 94 —4h 6e—0¢ | ‘oyeorpusg Sulu svipey ‘pT “ap “PT oy} puv “pT “op Summ = yY uoquier | “op osoues “oo ssoues | wreldeueiziA -ueyy UeIpuy -Ue o10sATT “YDONTHS Pan ‘anaNvg | ‘unaoyN ‘AWUOSAW | “SVUavi | ‘sjon.yuos burynu wuayn ayyndys ssahing yorym sof sa.o-asaunbunw unrvpuz fo sashjoup ‘TL Ta, | L4T.0—€ 0 TT-0O—60.0 80-0—L0.0 9[-0—€1L0 | 81-0 —ZT.0 a * snioydsoyq (Ea) 8—L L£—9 6—8 9—¢ - ‘ * Bors | | 8—9 L£—9 9--F LF 8 —9 . - wooly 8t—9F es—Ig¢ 4S—@S 8h—9F oco—Ts ‘ * gsouvsuryy ‘opela pug ‘apels 4s] | LI ~ ‘oy80Ip 00 ® ‘PT -udg Sulgoad loacay ‘oyppry| ‘eyeorpudg “sum Surddiyg 17 | -SOIqd SOOUTA ind{giatyg “op BuVUT wIpUT peayag | “ONE WH9UPO. *Vuy aNVHG | ‘VUYONVAG GNVYMEOYN | syovevg | ‘VOEYHE Poa “LOraisIa | ‘anapyN “‘SHONIAOWd TVWINGO Teen 5 | AVaOT ‘SHONTAOWA Cuap. XXIV.] ANALYSES. 515 Analyses of the Manganese-ores of the World. In tables 72 and 73 I give the limits and averages, respectively, of figures of analysis of cargoes of manganese-ores Analyses of cargoes : : 3 of Indian and foreign | and manganiferous iron-ores landed during the cliaats at Mid- years 1897—1906 at Middlesborough. The , figures were obtained by Dr. T, H. Holland in 1906 and represent not only Indian manganese-ore, but also the man- ganese-ores of the Caucasus, Brazil, and Chile, and the manganiferous iron-ores of Greece and Spain (vd Carthagena). From these figures it will be seen that the Indian ores contain less moisture than those of the other countries. Some of the latter contain such large quantities of moisture—Caucasus, 8°67% ; Brazil, 11°35% ; and Spain, 8°44°4—that it is necessary to reduce the analyses to their condition when dried at 100°C. before any fair comparison can be made. This has been done by assuming that the constituents of the ores not given in the ‘as received’ columns would if determined make the analyses add up exactly to 100. From the figures representing the dried ores it will be seen that the Indian ores stand first as regards manganese contents, with Brazil a close second : as regards silica, Brazil stands first, with India second : as regards phos- phorus, however, India stands last but one, the only ores containing more phosphorus being those of Russia : the Indian ores contain much less iron than the manganiferous iron-ores cf other countries; but of the true manganese-ores they contain the highest amounts of iron, in spite of the fact that they also contain the highest amounts of manganese. This feature of the Indian ores as regards iron contents may be regarded as a point in their favour, or otherwise, according to the use to which the ores are to be applied It is true that the high iron contents makes it more difficult to manufacture the very highest grades of ferro- manganese from the Indian ores ; but on the other hand if the very highest grades are not required then the iron is of considerable value. Both manganese and iron are of use in this case, and the buyer obtains the following totals of Mn + Fe when he buys the ores of the different countries :— Mn + Fe % India . . 4 : j : ; : P ; 57:17 Brazil . ‘ ‘ ‘ : é - : : : 54:09 Russia . ° F : : ; i : ‘ ‘ 50°41 Chile. : : ‘ : P 7 ; ; : 48°40 Greece . ‘ : : Z , : ‘ : : 47:99 Spain. é 2 - é A ‘ : é A 44°27 516 MANGANESE DEPOSITS OF INDIA: ECoNOMIcS. [Parr II]: As regards phosphorus, the figures for the Indian ores are rather mis- leading ; for an examination of the analyses from which these figures have been taken shows that the ores consist of two different varieties, The majority of analyses are typical of the ores of the Central Provinces, whilst four of them probably represent ores from the Vizagapatam district. I have accordingly separated them into two groups, of which the limits and averages are given in tables 74 and 75. From these figures it will be seen that the Central Provinces ores average 0°096% and the Vizagapatam ones 0°291% in phosphorus. ee eee 517 ANALYSBS. Cuar. XXIV.| ] 22.61—81.9 08.01--02.9 SLZI—FL-Z || LF-8T—Z6-TT 82-81—L0.% zs ¥L-3 —96.0 ; €L-% —#S-0 %20-0—200.0 8£0-0 —¢T0.0 +#0-0 —Z10.0 | 810.9 —600-0 16.L1—06.9 02-6 —Ge.¢ ZG.11—68-6 | 91-6 —ZT.9 GL.0F—88-9T GL-EF—G6.96 | 9L.26—96-8T | %¢.0 —oz.0 8L-1G -G8-L 1Z-€6—TF-OT FF-FC—E9-8 | 9°.66—FF.9F ae ; ; é | “G06T-L68T £06T-L68T 9061-L68T €061-868T ¥G 8 ee #S . : 6 ‘dase paunw) | any | snoleyiuesuey pt) NIvdg (‘VNaNV HEavO *so010-WOIl SnoIoyTUesURT bic fc &¢ 6:69) —| *e10-asouesUR yy 08.21—Z6.0 L¢.61— 69.6 01-0 —ZLT0.0 824.4 —08.0 92-8 —G¢.6 FI-8F—CO. LE 9061-8681 *910-asoues ue 8¢.cI— 26.8 €.G1—L9.¢ LT.0 —60-0 90-61—T6.9 £60 —8&-0 86-84—¥L.-0F | *ATIHO *TIZVU 9061-8681 | *(sas -voaVvo) Yissay | | ———————————— 81-€1—€9.€ $9.4 —16.0 T&E-0 —9¢0.0 66.6 —9.6 69- 1I— 8-8 €¢.F°—E1.GF 9061-0061 9@ ‘O40 S19}4VUL SNOdOTIIS ‘eUIUUNT PY 9IN4STOP, snioydsoyg : a eons uoly osouesueyy “poled *s9021v0 JO JequINN *a10 JO sse[D *VIGNT *AUINOOD ee a ee burinp ybnosogsyppryy yw papun) sa1o-uod snosafrunbunu pun saio- (‘poataoar sy) ‘906I—L68T sHvh oT ay) "GL ATEV L, asaunbunu fo saobao Jo sashyoun fo spun] Economics. [Part III MANGANESE DEPOSITS OF INDIA 518 £9-GL cé.8 | 40-8 G9.¢1 | Z&.2L 80-6 €L.2 LL-6L | 99.11 08-9 cL.9 ‘oye “10}4RUI snovoT|is ‘euruINyy | | | ay FF.8 sad gees | 6L-F <* tout i ce. U0 on 19.8 rae ZL-0 3 ‘ c * aI 4STOyy | | ! | 310.0 €10.0 €20-0 | $20.0 220-0 ¢10.0 ¢10.0 660.0 90.0 {91.0 | L¥T.0 Lé1.0 921.0 : J i snioydsoyg | YZ.Z1 SLU €¢.4 eld | 18.1 &€.2 92.2 F0-6 18. LT.OF 62.6 Th9 | 296 > ‘ i y vols | | | | FL-8G 61.12 C&8.1F | $€0-18| 9.62 [F-0 1¥-0 8L-E 8. €8.0 92.0 1-9 92.9 ; : * y dol] €L-12 C$.61 10.61 96.91 CL.9T 66.24 (¢. LF TE.0¢ 09.4% 89. 6F | 82. oF 98-06 6F.0¢ : o ‘ OSOUVSUE IY — = } : — | “9.001 |*peataoar “0.001 ‘00001 |*P9ATe00IT) “H.001 |"P9ATVI01) “9,001 |‘ peateded) “9,001 |\*paAteood | ‘9.001 |*paateoer| , : ye pod) sy wpouq |yepea) sv | yepera| sy |qepouq| sy |4e poud| sV¥ yepouq| s¥ Sjs4yeue Suyyodex Jo pouyeK = -— || ——= =| = eS ar = es £061—2L681 £061—Z2681) 9061—Z2681 | £061—8681 9061—8681 9061—868T 906I—O06L “polled ¥Z 8 £5 6 CZ LL 9% *s2031v0 JO JequUINN *910-WOIl “paunopny, “Md sNoLa LSU = = ae | ‘e10-esoursue yy *910-9SouRsURy “910-asoURsURy *910-asouvsuRyy *a10 JO sseID *910-T01I SNOIapIURSURIY *( VNEDVHL “(sas “4VO p20) NIVag “Hoaday “HTIHD “TIZVU -YooVO) VIssay “AUINNOD —_—_——X—X——_):9:. __— ___———a—X—snvooe ‘906I—ZL68T sivah oT ayn buranp ybnosogsayppryy 7 papun saso-uos snosafrunbunu pun sato-asaunbunw fo saobiva fo sashyoun fo unayy ‘GL, HIGV, Cuap. XXIV. | ANALYSES. 519 TABLE 74. Limits of analyses of Indian ores in Table 72 arranged according to probable source. eT | | Central Provinces, | and possibly Jhabua | Vizagapatam. and Panch Mahdals. Source oi ore. | Number of cargoes. | 22 4 Manganese : : : . : | 47°25 —54'53 42:13 —47 53 Tron . A - : “ ° . 3°85 — 7:98 9714 —11°69 Silica - ‘ = ; : : 3°33 — 9:99 2°63 — 3-66 Phosphorus : A : : : 0-056— 0163 0:235— 9°331 Mositure . : : : : , 0-21 — 2°64 064 — 0:95 TABLE 75. Mean of analyses of Indian ores in Table 73 arranged according to probable source. | Central Provinces, Source of ore. | and possibly Jhabua Vizagapatam. and Panch Mahals. Number of cargoes. 22 4 Manganese , 5 : ° : : 51°31 45°95 Tron . . = ; S| 5°53 10°29 Silica : 5 : 2 - : 61S 310 Phosphorus ; : : 5 A 0-096 0-291 Moisture . . A : , a 0-71 | 0°76 Since the figures given in tables 72 and 73 represent a few only of the manganese-ore producing countries of the world a ot wae worla, - give in table 76 a further set of figures taken from W. Venator’s paper entitled the ‘Die Deckung des Bedarfs an Manganerzen’, and published in Stahl und Eisen, XXVI, pp. 146-148 (1906). 520 TABLE 76. Analyses of the manganese-ores of the world. Source of Ore. Mn. BOSNiA : Cevljanovic, dressed ore 46°0) Do. do. 50°42 BRAZIL : | Miguel Burnier . 55°00 Carlos Wigg 6 - | 44°43 , 2°99 0°94 Dried ore . ° 53°18 3°58 £1°13 | Average ore | 54°08 0°90 1°05 English shipments, 1900 51°9—53"4 — 1°0—1 United States shipments, 1900 “ 151°9—53°5 — 1‘1—1 CHILE : Santiago 53°00 —_ —_ Coquimbo . 2 ; 52°66 — — Coquimbo . : . | 49°79 —- = FRANCE : Vieille Aure, Hautes- Pyrénées ‘ 46°00 — 37°00 Las Cabesses, raw . | 40°42 1°5—2 6—7 Do. roasted . 50—56 2°00 8—9 Saint-Giron 45°68 — 5°94 Ose : . | 56°48 —_ 6°48 Ral el Maden, Algiers . | 5°89 45°16 12°29 | GREECE : Milos 2 . | 32°16 3°32 19°76 Average Milos ; , | 34°73 3°00 22-92 Manganiferous iron-ore | 17°37 31°10 Micah HUNGARY : Kolozvar . 5 E 56°51 3°10 3°10 INDIA : Gosalpur . A - 54°29 1°41 3527. Average ore z. 51°43 5°6 9°52 ITALY : Monte Porcile : 48°75 = Monte Zenone 5 42°52 - 19°89 Island of St. Pietro, Sar- dinia 3 | 37-00 = = JAPAN : | No.1 : ; Sie — (ha No.5 . of || 44 “09 a 16°1 Average ore - | 48°871 --- 10°4 PANAMA : | Soledad mine ., | 60°60 0°2 4°67 Average of 3,500 tons . | 57<5 = 4°18 Average of 23,000 tons | 53°74 —- 8°68 Low-grade, siliceous ore 47°00 — 30°00 Conception, average of 6 ores | P 52°18 1 76( s) 4°36 “65 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part III: Reference or Hs Analyst. ( Vogel, Jahrbuch =, f.d, Eisenhiit- = tenwesen, 1900, Delite = Demaret-Freson, p. 6. 0°03 4°01 J. W. Westmore- land. = — J. W. Westmore- land ; 16°45 % moisture. 0°03 — 0°033) |15°8—18-2 J A £. Riley and Von E.tGottig. 0°037 |13°0—16°7 cee — |0 3.aD. Weeks, 0-02 x { 1894, p. 442. 0-04 cy bg ogel, ibid, p. 0°05 = 0°43 — Weeks, ibid, p. 0°47 445. 0°09 a Von E. Gottig. 0-04 — } . 0°06 — » Von E. Gottig. 0:04 5:9 \ 0°06 _ Vogel, op. cit., 1902, p. 226. 0°16 2°81 J. D. Weeks. 1895, p. 40. 0-09 — Von E, Géottig. = — _ |) Vogels sea ps \ 224, 0°06 = ‘ 0°06 = , Von E, Géttig. 0°08 — 0°01 1°70 J. Birkinbine, ea 2°78 1902, pp. 25 — = & 28, = J. Birkinbine, 1902, p. 80. ne ee eet Cuar. XXIV. ] ANALYSES. 521 TABLE 76—conceld. cl of the manganese-ores i the world—concld. | | Be Reference or Source of Ore. Mn. Fe, SiO.. iz. | H,0. Analyst. | 1 RUSSIA : | | ee Caucasus, range of5 ana- 45 °5—58 -2 0-4—1°35| 0°9—7-4 0-13—0° 48/0 “61—5 -78 on E. Géttig lyses : = ety u. | asen sas Do. average alee | 53°98 o-7ol 3) 4°62 0-34 2 -34( 9) 521. Pp ie eee), average | | 51°01 1-05 9°86 iL id See Von E. Géttig. Niko} ol (Ekaterinoslav) | 29°5 = - 0°24 — Do. do. 34°6 = 27-00 Oscs: i yee E. Gattig. Ekaterinenburg (Perm) 53°7 0°36 8-10 Tr. | tahl u. Kisen, Do. do. .| 51:2 1°33 9-33 CN 1891, p. 521. SPAIN : : Huelva Carbonate ore 4 28-26 6°58 4°95 = — 0. do. Cg (met: 3 on I 0°77 14°10 — — bs Santo Domingo 6 38°87 1°37 22-50 = = Vogel, ibid., p, Manganese Carbonate, 227. average from a cargo 38°33 Doo 10°85 0°10 | 1°54 Roasted ore . . | 49°6 = _ _ = ee Huelva : - : 43°70 2°51 17°10 0-22 2°19 Do. : : - | ° 49°35 os 13-0 0-10 = = = ee Cartagena, mangani- on E. Gottig. ferous iron-ore. ; 6°33 | 42°7 9°53 0°035 9°30 Las Rozas, do. 3 7°40 48°45 4°10 0°02 5°72 y UNITED STATES : - Arkansas, Batesville, 1 range of 5 analyses 50°4—56'°9|} —3-°66 0°7—2°1 0°10—0°29' —2-28 Do do. aver- age of 5 ana- ( = Ponte ) J. Pe eee lyses 54°90 pe says} nts ia 2°28(% 1895, p- 3, Do. do. Key- 3°66( 4) 1°36. :) ( ( et seq. stone mine . 57°30 1°75 2°31 0°12 — Do. Martin mine 60°50 1°61 1-0 O17 10°45 California, Corral Hollow 47°58 2°28 1°98 = oe Do. Red Rock .| 27°95 | 3:72 35-32 0-61 =e Mey Xs Georgia, Cartersville . 60°61 1°45 — 0-05 — \ J. Birkinbine, Do. do. 2°30 52°02 “= 0-24 = | 1902, p. 15, Do. do. aver- } SiO, rarely over ageoi7 .| 41-47 15°41 — 0-14 = 110 % Pete Jo on ave ° Do. Cave Spring, aa Birkinbine, pure ore . 53-44 1°98 7°79 0°06 1°56 1902, p. 16. Do Dobbins mine 52°72 4°49 4°30 0°19 = > Do. do. - 48°83 5°40 5°05 = = Do. Dademine . 30°32 23 °9 6°37 071 >= | Do. do. . : 43°45 4°26 16°45 0°10 = Do. do. . 42°93 8°53 12°30 O-ll = | Indian Territory Lehigh, | average of Fe 38-90 7°06 1°45 0°06 4°37 $J. D. Weeks, Lake Superior, high. 12°02 47-93 — 0°05 a | 1895, p. 403, et Do. low e 4°39 56°35 — 0°05 — seq. Virginia, Crimora mine 57°29 0°37 - 0°075 — Do. do. average ore " 49°08 2°83 | 10°21 0°10 — Do. Kendall «& J Flick’s mine . 48°25 2°70 | 10°50 — 4°00 | | The Rarer Constituents of Indian Manganese-ores. From the preceding tables of analyses a good idea can be obtained of the proportions in which the constituents that are taken into account 11 H 522 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part IIT: in the valuation of manganese-ores are present in the Indian ores. I now propose to notice in turn the various constituents found in the Indian ores that are not taken into account in the commercial valuation of ores, ‘Except where I state otherwise I shall confine myself to the analyses made by the Imperial Institute and Messrs. J. and H. S. Pattinson of samples collected and specimens selected by myself. I have 20 complete analyses and 62 partial analyses by the Imperial Institute, and 25 com- plete and 34 partial analyses by J. and H. S. Pattinson, from which to draw conclusions. Though all the partial analyses were of great use in the compilation of the preceding tables they mostly do not show any of the constituents to be considered here. Hence, except in the case of baryta and arsenic I have to rely almost entirely on the complete analy- ses. The analyses by the Imperial Institute represent the Central Provinces only ; those by J. and H. 8. Pattinson represent specimens and samples from Vizagapatam, Jhabua, Singhbhum, Panch Mahals, Satara, Ganjam, and a few from the Central Provinces a'so. Alumina is invariably present in the Indian manganese-ores, though usually to a small extent only. In 45 complete analyses the amount of this constituent ranges between 0°03 (Lohdongri) and 6°84% (Kodur), the average of the whole number being 1°33%. The form in which the alumina is present is a matter of speculation. In the case of psilomelane and hollandite I have found that it can usually be caleu- lated into the formula of the mineral as Al4(MnO;)3. ‘It is doubtless often present as an impurity mechanically included in the mineral. however. There is one variety of ore found in Mysore that seems, as far as can be judged from a single analysis by Mr. C. 8. Fawcitt, to be particularly aluminous. This is a dull oolitic to pisolitic ore. The specimen analysed came from Kumsi and yielded 13-04 per cent. AlgO3. » Alumina in manganese- ores. Baryta is an almost invariable constituent of manganese-ores. For this constituent I can refer not only to the 45 complete analyses, but also to a large number of the partial analyses carried out by J. and H.S. Pattinson. In 78 analyses the amount of baryta ranges from 0°00% in samples and specimens of mixed hbraunite and psilomelane, with braunite usually predominant, from Kodegéon, Kachi Dhéna. Kandri, and Kacharwghi, to 13°76 per cent. in a sample of psilomelane with pyrolusite from Bislampur, and 15:08°% in a specimen of psilomelane from Baryta in manganese- ores, Cuarp. XXIV.] RARER CONSTITUENTS OF ORES. 523 Tekrasai, both localities being in Singhbhum. A specimen of hollandite from Kajlidongri analysed by Mr. Winch showed 17-59% BaO. The baryta seems to be present in all or nearly ali of these ores in the form of barium manganate, Ba,MnO,, in the psilomelane or hollandite. It may also replace manganese in braunite as the molecule BaMnQy, The average amount in the 78 samples and specimens noticed above is 1-88%. Lime is almost invariably present in Indian manganese- ores. The 45 complete analyses show a maxi- mum of 5-60° in a sample of mixed psilomelane and braunite from Lohdongri, and a minimum of 0-00% in a picked specimen of pyrolusite from Pah. The average of the 45 is 1:07%. In many cases the lime is probably present as a manganate, CagyMnO;, as a part of the psilomelane or hollandite; but in some cases it probably replaces a portion of the manganese in braunite, e.g., in the specimen of this mineral from Sitapdr analysed by Mr, Blyth, and found to contain 4-28% CaO. Magnesia is another of the almost invariable constituents of Indian manganese-ores, only one analysis out of 45 ee in manganese- showing it absent. This is a specimen of mixed hollandite and braunite from Junawéni. The maximum amongst these 45 analyses is 3°15% in a specimen from Kachi Dhana consisting almost entirely of braunite. The average amount in the 45 analyses is 0°539% MgO. The magnesia probably plays a similar part in manganese-ores to the lime. Lime in manganese-ores. Alkalies sometimes form quite an important part of the Indian man- ganese-ores, potash being much more important shes otash in manganese- than soda. In 25 analyses by J. and H. 8S. Pattinson the lowest amount of K,0 is 0-05% in specimens from Guguldoho and Kajhidongri. In 19 cases the percentage of K,0 is over 1, the highest amounts being 3-75% in psilomelane con- taining braunite from Kodur, 3-31% in hollandite with braunite from Balaghét, 3-25% in lead-like psilomelane from Avagudem, 3-10% in psilomelane from Guguldoho, and 2:63% in psilomelane from Tekrasai. The average amount of KO in these 25 analyses is 11794. In 21 analyses by the Imperial Institute the amount of K,O ranges from a trace in four cases—namely, braunite with a little psilomelane from Kachi Dhana, pyrolusite from Pali, vredenburgite from Beldongri, and braunite containing a little psilomelane from Kacharwahi—to 0:82% in a samrle Il H 2 524 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Parr IIT: of mixed psilomelane and braunite from Kodegdon, and 0:50% ina specimen of braunite with psilomelane from Kandri. The average of these 21 is 0:175% KO. The average of the whole 46 analyses is 0°71% K,0. ‘The results obtained by the two sets of analysts seem at first sight to be very discrepant. But it must be remembered that the specimens analysed by the Imperal Institute did not include any specimens of psilomelane unmixed with braunite; whilst amongst the specimens analysed by J. and H. 8. Pattinson there were several pieces of pure psilomelane, which is the manganese-ore that contains the largest quanti- ties of alkahes. The potash and soda in this mineral probably occur as K,MnO; and NayMnO;, respectively. In the case of the soda, which is present in much smaller amount than the potash, the two sets of analyses agree very well. 21 analyses by the Imperial Institute show soda present in every case, the smallest amount being 0-13%, and the largest 0-50°, this latter being found in a specimen of braunite mixed with a certain proportion of psilomelane, from Kandri. The 25 analyses by J. and H. 8. Pattinson show from as little as 0-02% Na,O ina specimen of the lead-like psilomelane of Avagudem, to 0-57% in the hollandite of Baélaghdét. The average amount in the total of 46 analyses is 0-24%, which is one-third of the average amount of K,0. Soda in manganese-ores. An unexpected constituent of the Indian manganese-ores is arsenic. The finding of three different species of arsenates associated with the Indian manganese-ore deposits is noticed on page 218 in the section of mineralogy. It was the detection of the Sitapdér arsenate that led to the testing of the Indian ores generally for this constituent. A sample of the Sitapaér ore was cleaned into two samples, one free from visible arsenate—which is practi- cally white and hence easily separated—and the other containing all the visible arsenate, The amounts of arsenic oxide, As,O;, were found to be 0-003% and 0-095% in the two cases. Fifty-nine samples and specimens of Indian manganese-ores were tested for this constituent. Of these, all tested by the Imperial Institute have been found to contain arsenic, whilst of those tested by Messrs. J. and H. 8. Pattinson, 15 have been found to be free from arsenic, and 24 to contain it. The maximum was 0-3059% As,O; found in a sample of mixed psilomelane, braunite, and pyrolusite, from Kajlidongri, one of the arsenate localities. Other results of 0-050 or over are: 0-214%, 0-055%, and 0-050%, in other samples from Kajlidongri, 0-066% in a sample of mixed psilomelane, Arsenic in manganese- ores. Cuar. XXIV.| RARER CONSTITUENTS OF ORES. 525 braunite, and soft oxide, from Méndni; and 0-055% in a sample of psilomelane containing some pyrolusite from Sivardjpur. The average of the 59 determinations is 0-023°%. This is fortunately too small an amount to affect the commercial value of the ores. Manganese-ores could probably stand the presence of a considerably larger amount of arsenic than the above without the market value being affected ; for such amounts of arsenic would probably be volatilized off in the blast furnace. Every one of 25 analyses by J. and H. 8S. Pattinson shows a small amount of sulphur. There is remarkable uni- formity between the amounts present, the largest being 0-060°%, in a sample from Kajli- dongri, and the smallest 0-014°% in a specimen from Garbham. The average of the whole 25 is 0-029%. The sulphur may be suspected to be present in the form of minute quantities of barytes, especially as the maximum figure, 0-060, applies to K4jlidongri, in the ores of which I have recognized barytes. Such small amounts of sulphur do no harm. Indeed manganese-ores could probably stand the presence of a consider- _ able quantity of sulphur, without their commercial value being reduced, except in so far as the sulphur took the place of manganese-ore ; for manganese acts as a remover of sulphur in the furnace. Sulphur in manganese- ores. There seems to be considerable difference between the results of tests _ made by different chemists on Indian manga- Cobalt and nickel in : manganese-ores. nese-ores for the presence of cobalt and nickel. In many cases the chemists attached to the mining companies have been unable to prove the presence of these con- stituents ; whilst in other cases they have detected them. In some analyses that I once made of some Indian ores I found 0°48% of CoO + NiO ina picked specimen of mixed psilomelane-braunite ore from Kodegdon ; 0°17 of CoO and 0°38 of NiO in a specimen of wad from Sontulai in the Hoshangdbdd district of the Central Provinces ; and 0:27 of CoO and 0°56 of NiO in a specimen of conglomerate cemented by psilomelane from Pola Khal in the Dhar Forest, Central India. Dr. T. L. Walker found 0°82% of CoO in a specimen of wad from Olatura in the Kalahandi State. In the samples sent to the Imperial Institute the oxides of cobalt, nickel, and copper, were all determined together. The amounts of these constituents in 19 analyses vary from nil to 0°08, the average being 0°022%. These analyeges all represented specimens and samples from the Nagpur-Balaghat 526 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part IIT: area of the Central Provinces. In 25 analyses by Messrs, J. and H. 8, Pattinson, cobalt is absent from 3 analyses of Kajlidongri samples, and from one of a sample from Mandri. It is shewn as traces only in two analyses of specimens from Kajlidongri. In the remaining analyses it is given as present, the highest amounts being 0°35%, 0°25%, and 0-20%, in three specimens of psilomelane from Tekrasai. and 0°20% in a specimen of braunite crystals from Kacharwahi. The average of the whole 25 is 0°090%, and of the 19 analyses in which it is estimated, 0°120°%. Nickel oxide is returned as absent in 18 out of these 25 analyses, and present in the remainder. The highest amounts are 0°20°( and 0°15° in specimens of psilomelane from Tekrasai. The average for the whole 25 analyses is 0°027% and for the 7 in which it is present is 0°0959%,. Copper is sometimes found in the Indian manganese-ores, though, ; as in the case of cobalt and nickel, always in Copper in manganese- ofc ores. small quantities. The largest amount found was in the sample of wad from Sontulai already mentioned, the amount being 0°47. In the samples and specimens analysed at the Imperial Institute, the copper was returned with the nickel and cobalt, for which see the preceding paragraph. In the 25 analyses by J. and H. 8S. Pattinson copper was found to be present in every case, although in three cases, Guguldoho, Balaghat, and Mandri, all in the Central Provinces, the amount returned was only a trace. The highest amount of CuO is 0°15°% found im a sample from Kajlidongri. 0°034% isthe average amount in the 25 analyses. It is mteresting to note that a specimen of gondite from Wagora showed 002%: a specimen of opalized kodurite from Kotakarra 0°02% ; and one of opalized kodurite from Boirani in Ganjam, a trace of CuO. Gondite and kodurite are of course the rocks from which at least a portion of the manganese-ores of the Central Provinces and Vizagapatam, respectively, have been derived. Itis also of interest to notice that the analyses of these rocks do not show the presence of oxides of cobalt and nickel. Out of 4 samples and 21 specimens in which lead was looked for by J. and H. 8. Pattinson, this constituent was found in three samples only, all from Kajlidongri. The amounts were 0°01, 0°02, and 0°02%. An analysis made by James EK. Furguson of London, of a sample taken by Mr. J. H. Goodchild to represent the whole of the Mandvi Bir-Junawani ore-band showed 0°013% PbO, Lead in manganese-ores. Cuarp. XXIV.| RARER CONS'TITUENTS OF ORES. 527 In the 25 analyses of specimens and samples by J. and H. 8S. Pattirn- son zinc oxide is returned as absent in 9 eases, as a trace in one, and is determined in the remaining cases. The maximum amount of ZnO is 0°55%, found in a specimen of psilomelane from Tekrasai. Amounts of 0°40% and 0°30% ZnO were found in two other specimens of the same mineral from the same locality. The average amount in the whole 25 analyses is 0° 102% ZnO. The analysis of the Junawdni sample taken by Mr. Goodchild, noticed in the preceding paragraph, shows 0°070% ZnO. An analysis by Messrs. Pattinson and Stead of a 300-ton cargo of Kodegdon ore shows a trace of this constituent. Zine in manganese-ores. It is noticeable that all the rare metallic constituents, cobalt, nickel, copper, lead, and zinc, found in the Indian manganese-ores, tend to occur in greatest amount in specimens of wad and psilomelane. The most noticeable examples are the wad-like psilomelanes of Sontulai and Tekrasai. It is probable that these constituents tend to take the form of manganates of the general formula RyMnO; in the ores in which they are found, though they might also occur in braunite in molecules of the general formula RMnOs. In the 25 analyses by J. and H. 8. Pattinson titanic oxide is returned as absent in four cases, as a trace in one, and is determined in the remaining analyses, The maximum amounts are 0°14% in a specimen of vredenburgite from Garividi, 0°14% and 0°12% in two samples of mixed psilomelane-braunite ores from Kajlidongri, and 0°13% in a specimen of speckled ore (psilomelane, braunite, and soft oxides) from Guguldoho. The average in the whole 25 analyses is 0°0589% TiOg. Titanium in manganese- ores. The amount of combined water in Indian manganese-ores varies greatly with the nature of the ore. It is never nil. In 45 analyses the highest amounts are 7°30% in wad from Garbhim; 6°16% in beldongrite, a variety of psilomelane from Beldongri; 5°50°4 in wad from Kodur ; and 4:40% in material mtermediate in physical appearance between wad and psilomelane, from Garbham. The average amount in the 45 analyses is 2°01%. It may be stated as a rough rule that the larger the amount of psilomelane in an ore the larger is likely to be the amount of combined water ; and the larger the amount of braunite the smaller the amount of combined water; whilst wad contains an even Combined water in man- gamese-ores. 528 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Parr III: larger proportion of combined water than psilomelane. In the psilomelane the water is probably present as HyMnO;. Manganese-ores, if free from rhodochrosite, should not contain any carbon dioxide. In 28 analyses by the Imperial Institute, however, COg is returned as present in every case but one. The highest amounts are 3°49 in a sample from Ghogara in the Pench River; 1:14% in a sample of nodule ore from Pali; and 0°41% in a sample of ore, largely braunite, from Gaimukh. In the first two cases the presence of the carbon dioxide is to be ascribed to calcite; for the ores were obtained from crystalline limestones; and in the third case rhodochrosite was seen to be present in the ore. In all the other examples the highest amount of COg is 0°35%; and the average of these 25, excluding the foregoing 3, is 0°106%; and as there seems to be no way of accounting for the presence of this COg by means of visible calcite or rhodochrosite, it seems necessary to suppose that there may be microscopic amounts of one or other of these minerals disseminated through the ores, the calcite having perhaps been introduced by percolating waters. Another hypothesis is that these small amounts are the result of experimental errors connected with the determination of such small amounts of a gas. In 25 analyses by Messrs. J. and H. S. Pattinson this constituent is returned as absent in every case. Carbon dioxide in manganese-ores. et CHAPTER XXV. ECONOMICS & MINING—contonued. Value of the Indian Manganese-ore Production. Official statistices—The f.0.b. or export value, the true value to India—Tables of export values—The c.i.f. or true market values—Comparison of the value of India’s manganese-ore production with that of other minerals—The ferro- manganese value of the Indian manganese-ore production—Prices of ferro- manganese—Taking the ferro-manganese value, the Indian manganese-ore production for 1906 is ab»ut equal in value to that of coal—Enormous loss to India through not manufacturing ferro-manganese. It will be interesting to see what is the total value of the manganese ore exported every year from India. There are of course several ways of stating the value. Manganese-ore possesses one value per ton as stacked at the pit’s mouth, another as delivered f.o.r. at the railhead, a third as delivered f.0.b. on board the ship at the port of shipment, a fourth as delivered c.7.f. at the port of destination, and a fifth after _it has been converted into ferro-manganese. With the price at fourteen pence per unit the average value of Central Provinces’ ore may be taken as :— Rs, a. 19 10 at the pit’s mouth. Bll A OE 30) 2) f.0:0: 43° 12 cit.f: The question arises us to which of these values should be made use of in the compilation of the mineral statistics of India. The figures for the exports of manganese-ore for every year ending 31st March are given in the Annual Statements of Trade and Navigation of British India, and the export values of the ore are given also. These figures of values are much below the true export (or f.0.b.) values. In the Statistics of Mineral Production in India, issued annually, the export values of the ores are also given ; and as in the preceding case these are usually considerably less than the true export values. I do not know the exact way in which these figures are obtained, but I expect they are based on figures supplied by the mining companies exporting the ore. In the following table I give the values, stated both in rupees and in sterling, that have been given in the Statistics of Mineral Production in India from year to year. Official Indian statistics. 530 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Parr III]: TABLE 77. Value of the I ndian manganese-ore production as reported in the Sta- tistics of Mineral Production. | TOTAL VALUE IN RUPEES. | VALUE PER TON. Year. | Value in [ = <1 oe Central Pro- naka Tots Sterling. Central Ee. vinces. | Madras. Total. | | Provinces. | Madras. | Average. Ma, + & ore EP ee | ee na Rs | Rs Rs. £ ral Rs. Rs. 1893 | 21,301 21,301 1,420 | 6°80 6°80 1894 | 77,651 77,651 5,177 6°80 6°80 1895 | 1,07,636 1,07,636 7,176 6°80 6°80 1896 | 3,87, 022 —-3,87,022 25,801 6°80 6°80 1897 | | 5,01,429 | 5,01,429 33,429 6°80 6°80 1898 ry 11, 386 4,11,386 27,426 | 6°80 6°80 1899 5,92,936 5,92,936 39,529 6°80 6°80 1900 5,30,340 6,29, 223 11,59,563 77,304 15°00 6°80 9°07 1901 676,420 | 5,20,369 11,86,789 79,119 15°00 6°80 9°81 1902 1394135! | 4,63,938 18,58,072 123,872 15:00 | 6°80 11°77 1903 15,23.310 4, 67,807 49,91,1172 132,741 15-00 | 7°37 12-06 1904 | (3) ' 19344,480 129,632 | 12°94 1905 (3) | 37,24,635 248,309 | | 14°67 1906 | () | 65,29,020 435,268 | Massa, | ‘ | ' Totals : ; : ; . | 2,04,93,038 1,366,203 veer eaees ae eee ee oe 2 ee ee es Seen It is a difficult question to decide which of the values noticed on page 529 should be taken as the true value of the Indian manganese-ore. The true market value is of course the c.7.f. value. But the proportion of this value that is made up of ocean freight and destination charges cannot be regarded, except in an indirect way, as of value to India. Hence I think the true value of the ore to India is the export or f.0.b. value ; for all the expenses incurred in placing the ore at a port have Benen ed some one in India. The difference be- tween the /.o.b. value and the cost of putting the ore /.0.b. a vessel at one of the ports is of course the profit to the mine owner. And this profit goes to companies or individuals working in India; and although it is true that a considerable proportion of these profits finds its way when distributed as dividends to people living out of India, yet it increases the capital of people interested in India, and so may be regarded as increasing the stock of capital available for use in this country. For these reasons, in the following tables, in which I have made an attempt to arrive at the approximate value 1 The figure reported is 13,44,135, due to an error in cain Sint: tie meine at Rs, 15 per ton, 2 This total does not include Jhabua in Central India, which began to produce in this year. * Values for the different provinces not reported separately, and only in sterling. The f.c.b. or export value the true value to India. Cuar. XXV.] EXPORT VALUES. 531 of the manganese-ore mined in India from the beginning of the industry in 1892 to the end of 1906, Ihave given the export values as being those that give the truest expression of the value of the manganese industry to India. The calculation of these figures has. of course, been largely a matter of guess-work or estimation. For I have little information as to the prices mine owners have received from their ores from time to time, nor as to the average com- position of the ores exported from year to year. I have consequently had to take the quotations given in the Mining Journal and assume that these are the prices that have been obtained by the Indian manganese workers, modifying them where it seemed necessary : I have also had to assign to the ores of each area an average value for the manganese—and in the case of the lower grade ores for the iron—contents, this value being based on what I know of the composition of the ores cf each area; but this figure is not necessarily the same as, though close to, the figures for each year on which the mine operator: have been paid. Still I think that the errors are not as a rule serious. and that probably they more or less balance one another. Thus itis possible that I have sometimes allowed slightly higher prices for the Vizagapatam ores than have been obtained ; whilst I know that in the case of the Central Provinces contracts have sometimes been made a long way ahead at times of low prices, so that it has not been possible for full advantage to be taken of the prices when they have risen. Other operators, on the other hand, have held back their stocks and never sold far ahead, so that they have been able to take a full advantage of the rises im price, as for example during 1906. Then, again. in some cases, ores that according to their manganese percentage should be graded as second or third grade ores, have been able at times of high prices and comparative famine in manganese-ore to fetch prices corresponding to the grade of ore above. I have allowed as far as possible for all these pomts ; [have also allowed a price of 5 cents or 24 pence per unit of iron, this being the American pay- ment, in cases where I think that the price according to the grade of the ore. for manganese alore, is lower than the ore probably fetched ; but I do not know that any payment for iron has actually been obtained in these cases. I do not think it will be possible to compile such figures with greater accuracy unless the companies concerned are willing to divulge the average prices and percentages of manganese obtained on their cargoes irom year to vear. It is also to be noted that I have Tables of export value. 532 MANGANESE DEPOSITS OF INDIA: ECoNoMIcs. [Parr ITI: assigned values to ores from Belgaum and Singhbhum although, as far as | am aware, none of the ore extracted in these two districts had been exported up to the end of 1906. The amounts of ore extracted in these two districts is, however small, so that the values of these «res do not make much difference in the totals. It is better to include the values of these ores under the years in which they were extracted, rather than when they were exported, so as to prevent confusion in the statistics. It will be seen from the tables that the total export value of the ore mined in the Vizagapatam district during the 15 vears 1892 to 1906 is Rs. 1,24,19,012 or £827,934, giving an average annual value of Rs. 8,.27.934 or £55,196 ; whilst the total export value of the ore mined in the four districts of Balaghat, Bhandara, Chhindwara, and Nagpur, in the Central Provinces, during the 7 years 1900 to 1906, is Rs. 2,13,16,282 or £1,421,086, giving an average annual value of Rs. 30,45,183 or £203,012. The total export value of the Indian Production during these 15 years is Rs. 3,65,61,913 or £2,437,462. It has risen from Rs. 15,755 or £1,050 in 1892 to Rs.1,45,36,131 or £969,078 in 1906, with an average annual value for the whole 15 years of Rs. 24,37,462 or £162,497, and for the 7 years 1900 to 1906 of Rs. 45,26,276 or £301,752. Cuap. XXV.| EXPORT VALUES. 533 TABLE,78 . Export values of the manganese-ore produced in the Madras Presidency from 1892 to 1906. TOTAL EXPORT (f. 0. b, Value VaLUE. co) | |Assumed Assumed 7.0.6. Production | priceper per cent. Value Year. District. | unit of of Mn. c. t. f, at for year fo ad tog Ne ore. (°)| anil 34. Ginn In sterling. —_—__}— ——_— | | Pence. Rs. a. Rs. a. | Long tons. | Rs. £ 1892 Vizagapatam.) 13 | 46 Mn | 37 6 23 6 674 | 15,755 1,050 1393 | Do. ' 12} ts 35 15 | 21 6 3,130 66,904 4,460 1894 Do. 10 9 28 12 | 14 12 11,410 1,68,297 11,220 1895 Do. 93 SS 27 5 13.5 15,816 2,10,550 14,037 1896 Do. ll ra 31 10 17 10 56,869 10,02,316 66,821 1897 Do. 103 “ 30 3 | 16 3 74,467 12,05,435 80,362 1398 Do. 94 2 27 5 135 62,980 8,38,421 35,895 1g99 Do. | 10% _ 2005) | 16. s 84,652 13,70,304 91,354 1900 Do. / 12 # 34.8 20 8 92,008 | 18,86,164 125,744 i901 Do. 10} a 30 3 16 3 76,473 12,37,907 82,527 1902 De: || 9} . 26 9 112 9 68,171 8,56,398 57,093 1903 Do. 8} 2 2% 7 110 7 63,074 6,58,335 43,889 1904 Do. 8k a 24 7 j 10 7 53,602 5,59,471 37,298 1905 Sandur 8} 2 23 11 911 1,200 11,525 775 * Vizagapatam| 8} » |2311 | ont 63,789 —«6,17,956 aay rane 1906 Sandur 11 a) ese 10 17 10 3,209 56,559 pad Visegapetam | 11 fe | 31:10 17 10 72,315 12,74,552 | 84,970 }—114,212 Do. 9} (3rd 37Mn. 23 12 9 12 39,186 3,82,063 Eel grade) +45 Fe. ie Ee Se a ee es — Rs Totals and averages. 9°96d, | 28 12 1412 843,025tons *,24,19,012 £827,934 a * 46%Mn. puts the Vizagapatam ores as 3rd grade. But they have often been much over 46 %, and probably always fetch 2nd grade prices, except the ferruginous ores entered separately under 1906. 2 For the ferruginous manganese-ores—3rd grade—I have added on 5 cents=24 annas per toa for each unit of iron. 3 Obtained by subtracting Rs. 14 from the ¢.#./. figures. In table 50 thefcost of landing the ore c. i. f. at its destination is given as Rs. 14-12-0. But the average figure given for ocean freight is ee bably too high when applied to all the past years, . MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Parr IIT: TABLE 79. Export values of the manganese-ores produced in the Central Provinces from 1960 to 1906. Year, 1900 1901 1902 1904 1905 1906 Totals a TR RY I A 2 Calculated from the ec. %. f. value by subtracting Rs. 14. ocean freight plus destination charges (Rs. 13-4) as given in table 50, and may be considered to allow for the fact that some of the ore goes to America, whilst a liltle is exported through Calcutta, Assum- | ed Value | Value | price Assum- per per Output per ed ton ¢.i.f. ton f.0.b.| for year District. unit |per cent. at | at from of Ist | of Mn. | U.K. | Indian table grade ports. | ports.! | No. 35. ore, ahi L eel eS a | | | Pence. Rs. a | Rs. a Long tons. | } | N4gpur. lees 52 45 15 | 31 15 47,257 Balaghat . ; | | (| 3,839 Bhandara . : 11g 52 | 38810 | 24 10) | 499 N&gpur 76,925 | | | Balaghét . : | | || 1,075 Bhandara . 7 io 52 BPA Ah wl Pals} 8 5,360 Nagpur | 68,819 | | Béléghét . . |) | | 7,898 Bhandara . - | 2104 52 335 | 19 5 4,998 Nagpur. acy | 95,051 Baélaghat . 4 G 10,323 Bhandara . A 9} 52 30 1 16 =) 8,559 Nagpur 66,142 | Balaghat | 16,246 Bhandara 9} D2 Smee LO 35,238 N4gpur : | 100,063 i} | | Baléghét ( oe 260 Bhandara . o | 5 “5 i lo ; Chhindwara |, ea DES aerate alec ee 7,486 Nagpur | . 146,117 average average) average 901,072 Rs. a. | Rs a. and averages. 11°58d, 37 10 23 10 tons. TOTAL EXPORT (f.0.0.) VALUE. In Indian | . currency. In sterling. ! Rs. = 15,09,270 | 100,618 94,535 12,288 } 138,407 18,94,278 36,538 | 99,160 2 93,923 12,73.152 |) 1,52,530 | 96,524 | °138,982 18,35,672 | | 1,65,813 1,37,479 ; > 91,047 10,62,406 | 2,60,951 5,66,010 }ro2,28 16,07,262 28,68,508 2,238,644 \ 30,55,017 ? 700,828 43,65,245 Rs.213,16,282] £1,421,086 en a a This is a little more than the cost of Cap. XXV. 1] EXPORT VALUES. 535 TABLE 80. Export values ‘of the manganese-ores produced in Bengal, Bombay, Centra! India, and Mysore, from 1903 to 1906. Assumed price ToTaL EXPORT per unit of Mn. Value (7.0.6.) VALUE. per inore » PS | | —.— Assumed) P& ton : : ee : er 3 ton duction 2 Province. Soe = = = ems ef. 7 y for year 3 | Z = S andFe. vu K Indian 770™ In In = 2 Ss . . ports. lable Indjai sterl- = 5 = ports. *"; 24. currency.| ing. — — s m Ss = } — Nn oo Pence. Pence. Pence. Rs. a. Rs. a. Long Rs, £ | tons. 1903] CentralIndia | Jhaébua . -- 9 < 47Mn. 267 #127 6,800 84,575 | 5,638 1904 u Here: iy 9 . 47Mn. | 267 | 12 7 | 11,564 1,43:827 | 91588 1905] Bombay Bataan ot 7 doMn-+ | 214) 7 4 40 290 19 10Fe 1906| Central India| Jhébua. Shi ey | 27Mn|23'8h) (9/8 30,251 /2,87,384 | 19,159 Bengal LSingei=! .. 12 .. | 47Mm. | 35 4) 21 4! 1,000 | 21-250 | 1,417 bhum ay } Eombay Ta io Of | 45Mn + | 279/189) 234 | 3,174 | 212 _10Fe 4 |Panch Ma- 133 ES .. 50Mn. | 42 3 | 28 3 | 7,286 (2,05,374 (13,692 hals. Central India ThAbua . - 12 =- 47Mn. 35 4 | 21 4 50,074 10,64,072) 70,938 Mysore Shimoga. ae 12 = oe 379 239 40,773 9,60,714 64,048 | OFe Tener. 3 am 9} 45Mn.+ 279/139 4,126 55,959 | 3,731 10Fe. ' | 2 Obtained py subtracting Rs. 14 from c.i.7. values, as in preceding tables. TABLE 81. Export values in Rupees, f.o.b. at Indian ports, of the manganese-ore produced in the various Provinces of I ndia from 1892 to 1906. = SY } ] Bengal. Bombay. | alg le i Madras. | Mysore. Totals. | Se | ; Rs. | Rs. Rs. Rs. Rs Rs. | Rs 1892 | 15,755 15,755 1893 | 66,904 66,904 1894 } 1,68,297 1,68,297 1805 2,10,550 2,10,550 1896 10,02,316 | 10,02,316 1897 12,05,435 2.05 1898 | 8,38,421 1399 | 13,70,304 1900 | 15,09,270 | 18,86,164 1901 20,01,101 12,37,907 32,3 1902 } 14,08,850 | 8,56,398 39° 65; 248 1903 84,575 20,84,726 6,58,335 28/277 ,636 1904 1,43,827 | 13,65,698 5,59,471 a 68, 996 1905 290 2,87,384 24,34,223 »29,581 3s 1906 21,250 2,08,548 | 10,64,072 | 1,05,12,414 17,153,174 10,16.673 Totals 21,250 | 2.08,838 15,79,858 | 2,13,16,282 | 1,24,19,012 10,16,673 3,65,61,913 536 MANGANESE DEPOSITS OF INDIA: ECONOMIcS. [Parr III: TABLE 82. Export valves in Sterling, f.0.b. at Indian ports, of the manganese-ore produced in the various Provinces of India from 1892 to 1906. j Bengal. Bombay. | Soaeet Se Madras. Mysore. Totals. { | £ £ £ £ H £ £ £ 1892 1,050 1,050 1892 4,460 4,460 1894 11,220 11,220 1£95 14,037 14,037 1256 66,821 66,821 1897 80,362 80,362 139% | 55,895 55,895 1s¢9 | 91,354 91,354 1900 | 300,618 125,744 226,362 1901 | | 133,407 82,527 215,934 1902 93,923 57,093 151,016 1903 5,638 138,982 43,889 188,509 1904 | 9,588 91,047 | 37,298 137,933 1905 19 | 19,159 162,281 41,972 223,431 1906 | 1,417 13,904 | 70,938 700,828 114,212 67,779 969,078 | ~. Totals’ 1,417 13,923 | 105,323 1,421,086 827,934 67,779 2,437,4 62 | The values given here are the export values. membered that the true value on the world’s The c.7./. or true market values. markets is the c.i.f. value. But it must be re- This can be ob- tained from the f.0.b. figures by the addition of Rs. 14 per ton. production for the last seven years shown below :— TABLE 83. This gives the total annual values of the Indian Values in sterling c.i.f. at destination of the manganese-ore produced in India from 1900 to 1906. Year. Rs. £ 1900 53,45,144 | 356,343 1901 54,47.312 363,154 1902 42,85,798 285,720 1303 53,17,130 354,475 1904 41,71,656 278,110 1985 68,15,456 454,364 1906 2,25,37,061 1.502,471 Average annual value 77,02,794 513,520 Total value for the 7 years 5,39,19,557 4,594,637 Cuar. XXV.j] VALUES OF CHIEF INDIAN MINERALS. 537 We can now compare the value of India’s manganese-ore production Gawpiamcon of India’s with that of her other mineral products. manganese-ore production Taking the export or /.0.b. values of the Indian with that of other minerals. ranganese-ore, and comparing them with the values for the other chief Indian minerals as given in the annval statistics of Mineral Production!, we see that in 1903, 1904, and 1905, manganese-ore was the sixth in value, being surpassed by gold, coal, petroleum, salt, and saltpetre, in the order named. But in 1906 manganese-ore jumped up to the third position, being surpassed only by gold and coal. The figures are shown in the following table :— TABLE 8&4. Values of the 8 chief mineral products of India for the years 1903 to 1906. 1903. 1904. 1905. | 1906. £ & | ia | an te Gold 2,303,144 | 2,366,079 (2,416,971 (2,230,284 Coal (a) 1,299,716 1.398 .826 141 9,443 (1,912,042 Manganese-ore ()) 188,509 137,933 | 223.431 969,078 Petroleum (a) 354,365 | 473,971 604,20° 574,238 Salt (a) 336,147 | 487,530 | 441,392 | 420,901 Saltpetre (b) 290.196 | 266,349 235,723 | 270,547 Mica (5) 86,296 | 97,932 | 142,008 | 259,544 Rubies 88,819 90,612 88.540 96,867 eeeasses oe (a) Spot prices ; (6) Export values. The above figures give roughly the relative values of the respective minerals to India ; but they do not give the true relative values cf these minerals on the world’s markets. The true values of the minerals are the values at the places where the minerals are to be used. The gold is, of course, appraised at its true market value. If the other substances 1 Ree. G. 8. I., XX XIII, p. 3, (1906); XXXIV, p.47, (1906); XXXVI, p. 65, 907). III [ 538 MANGANESE DEPOSITS OF INDIA: Economics. [Part III: were given their true market values where used, the true order of value of the first constituents would probably be found to be coal, petroleum, gold, manganese-ore, salt, and saltpetre. If we take the mineral pro- duction for 1906 and give the following values :—coal Rs. 7-8 per ton, petroleum 5 annas per gallon, salt spot price (avoiding duty), saltpetre 18s. 6d. per ewt. ¢.i.f. value ', manganese-ore its c.i.f. value, and mica its t.o.b, value 2, the following are the values of the eight chief mineral products :— £ Coal . - P - - - - - 4,891,625 Petroleum . - - : . ; 2 2,928,190 Gold : ~ - : - 2 = = 2,230,284 Manganese-ore . : - - : : : 1,502,471 Salt : P - : 3 s Z : 420,901 Saltpetre . = : . 5 ‘ 5 2 321,207 Mica : : ° : - “ Z - 258,782 Rubies 2 - 96,867 Even the comparison of the ¢.7./, value of manganese-ore with the thé -iAato eeipanee market values of the seven other mineral value of the Indian man- products noticed above, is not a fair one, Ganlese-ore production. for the reason that the c.z.f. value of man- ganese-ore is the value of the substance only before it is ready for use. Coal needs no working up, except when it is to be converted into coke, and is ready as soon as mined for the purpose for which it is used, namely as fuel. The petroleum is vaiued after it has been sufficiently refined and is ready for lighting purposes and as afuel. The salt and saltpetre are valued after being refined, so as to be ready for human consumption and the manufacture of gunpowder, respectively. The mica when valued has been separated from its matrix and cut into shapes and sizes and is ready for use, except in the case of the scrap from which micanite is manufactured. The rubies have been separated from their accompanying minerals and need no further treatment except cutting. The gold is only in the form of bullion; but it is given practically its full value and has been won from its ore after complex metallurgical treatment. For the value of the manganese-ore to be fairly comparable with that of the other constituents it should therefore be valued after it has been converted into ferro-manganese, 1 The mean of the prices quoted during 1906 for crude saltpetre in the Engineer- ing and Mining Journal. 2 I have given the j.0.0. value of the mica because I do not know the cost of sending itto Europe. This can form only a small portion of the total value of the naica, howev2t, so that the /.0.b. value is not much less than the ¢.1.7. value. Cuar. XXV.] FERRO-MANGANESE VALUES. 539 that is after the metallic manganese has been separated from its accom- panying constituents in the same way as the gold has been separated from its gangue. Of course, all the Indian manganese-ore is not converted into ferro- manganese ; but as itis not possible for me to say what proportion of it is converted into spiegeleisen, and what proportion is used in other ways ; and as it all could be converted into ferro-manganese we shall obtain the best idea of the potential value of the Indian manganese-ore, by supposing it all to be converted into ferro-manganese. In table 85 I give the weekly prices quoted in the Engineering and Mining Journal of New York from 1901 to 1907 ; the volumes of this journal for years previous to 1902 are not in the library of the Geological Survey of India, and so I cannot give the quotations previous to 1901. From the table it will be seen that the quotations vary between $41 in May 1904, and $150 in February 1906, with a mean for the whole period of $61°391. It will be noticed on comparing this table with table 27 on page 415 showing the variations in the price of manganese-ore from 1900 to 1907, that the price of ferro-manganese varies more or less in sympathy with that of manganese-ore, though the two are not strictly proportional, Hence as the prices for manganese-ore were on the average higher during the years 1892 to 1900 than in the succeeding years, we should probably not be over-estimating the average price of ferro- manganese during these years if we applied the same average as for the 7 years 1901 to 1907. But to be quite sure of not over-estimating let us take $50, or, say, £10 or Rs.150, as the average price per ton during the years before 1901. In table 86 I give (1) the annual totals for Indian manganese-ore production, (2) the number of tons of ferro- manganese they would give on the assumption that two tons of Indian manganese-ore would be required for the production of 1 ton of 80% ferro-manganese (allowing for a loss of 20% of the manganese in the smelting), (3) the average price of ferro-manganese per ton assumed for each year, and, finally, (4) the total value of the Indian ferro-man- ganese that could have been manufactured from the Indian manganese- ore produced each year. The fact that some of the Indian ore would not give as high grade ferro-manganese as 80% is more than neutralized by the fact that I have probably underestimated the price of ferro- manganese for the years previous to 1901. Prices of ferro-manganese. 1 In December 1905 one car-\ot was sold for $175. 11t 1 540 MANGANESE DEPOSITS OF INDIA: Economics. [Part IIT: TABLE 85. Average prices per ton, at Pittsburg, United States of America, of 80 per cent. ferro-manganese for the years 1901 to 1907. 1901 1902 1903 1904 1905 1906 1907 3 | $s. | s $ $ $ $ January : : 5 z -. | 62°50 | 52°50] 51 46 45 135 81 February = s : 62°50 | 52°50| 50 44 46 150 74 March : z 62°50 | 52°50) 50 43 47 140 75 April Z - | 58°50} 52°50] 50 42 51 125 7 aS 3 : 2 B . | 58°50] 52°50] 50 41 50 105 69 June . = A e 2 . | 58°50 |- 52°50 | 50 4 50 30 64 July .- E : : Z - | 53750 | 951750] 50 41 50 85 63 August . : : : B . | 53°50] 52°50] 49 41 50 85 62 September . 2 é : . | 53°50] 52°25 | 48 41 54 83 53 October : : ‘ ; .| 53°50] 51°25} 48 41 62 73 57 November . < 2 : : 53°50 52°50 48 42, 100 82 53 December é 4 . 2 2 52°50 51-00 7 422 125 83 52 Averageforyear 56°82 52°17 | 49°25 42-08 | 60°83 103-42 64°92 SS eee oTz.—Taken from the first number of the Engineering and Mining Journal of each year, Figures for 1902 compiled from the weekly quctaticns in this journal, the first number for this year being mis- sinz from the Geological Survey Library. Figures ior 1907 compiled in same way. In most cases the price represents ‘domestic’ ferro-manganese, t.c., made in United S‘ates of America ; but sometimes quotations ot English and German ferro-mangan>se have been used to fill up blank. They never vary greatly from the domestic quofation:. TABLE 8b. Value of the Indian manganese-ore production from 1892 to 1906, when converted to jerro-manganese. | | i } | ANNUAL VALUES OF FERRO-MANGANESE Tctalannual | Equivalent Average annual EQUIVALENTS OF THE MANGANESE-ORE Year. | [idian mangan- | amounts of 80% | price of ferro- ese-ore pro- | ferro-mangan- | ne per | duction. | ese. | ton. Se f i | | Teney. Tn sterling. 1 | Long tons. Long tons. = } Rs Zz 1392 | 674 337 nN 50,550 3,370 1893 3,130 1,563 2,34,750 15,650 1304 | 11,410 3,705 | 8,55,730 57,050 1295 | 15,816 7,908 | 1 1,86,200 79,080 1896 56,869 28,434 | 3 10 42,65,100 234.340 1897 74,467 37,234 | 55,85, 100 372.340 1898 62,930 31,490 47,23.500 314.900 i399 | «84,652 42,326 6348900 | po 1900 | - 139,265 69,632 | J £.04.44.800 696.320 1901 157,736 78,868 10°38 | -1,27,76,610 851.774 1902 144,325 72,163 10°3 1,11,49,185 743.979 1903 177,821 $3,910 | 9°55 1,27,36,350 349.090 1304 150,190 7 3,095 3 3 95.74.6053 638.307 1905 | 247,427 123,714 16°95 3.14.54.230 2.096.952 1906 571,495 285,747 | 17°4 7,45,79,970 4.971.993 Totals 1,898,257 949,128 13-06 18,59,85,650 12,397,710 (average) For the average annual price of ferro-manganese given in the fourth column, I have not taken the averages given in table 85; Cuar. XXV.] LOSS TO INDIA. 541 instead of this I have taken averages based on the last nine months of a given year and the three first months of the next. This is to allow for the fact that a certain time must elapse between the despatch of the ore from the mines and its conversion into ferro-manganese in America or Europe; so that ferro-manganese made from ore exported during a given year would come on to the market in time for the prices obtaining during the last nine months of that year Taking the ferro-man. Dd the first three of the next year. From this ganese value, the Indian table it will be seen that the value of the ferro- = Steak equal i ira ee manganese equivalent of the manganese-ore that of coal. produced in 1906 was nearly five million sterling or 74 crores of rupees. This valuation actually places manganese-ore at the head of the list of India’s mineral products for 1906. But the value given above for coal in this year is very little less than that of the manganese; and hence asboth valuations are based on assumptions it is better to say that the ferro-manganese value cf India’s 1906 production of manganese-ore is about equal to the true value of the coal. The chief interest of these figures does not, however. lie in the Enormous loss to India P0Sition they give to the Indian manganese-ore through not manufacturing production relative to that of the other Indian oo mineral products ; but in the enormous finan- cial loss they show that India suffers by the export of its manganes>- ore in the raw condition. Because the ore is exported in this condition the total value of the Indian manganese-ore production since 1892 to 1906 has been worth to India only 3 crores and 5 lakhs of rupees, or about £2,437,000. Whilst. if this ore had been con- verted into ferro-manganese in India, the least value to India would have been the export value of the ferro-manganese produced. The export value of the ferro-manganese is its market value where it is to be used minus the expenses incurred in getting it to those markets, on the assumption that none of it remains in India for home con- sumption. £1 or Rs. 15 may be taken as a fair average for the expenses that would be incurred in putting the ferro-manganese manu- factured in India on the European and American markets. Making this deduction per ton from the values given in table 86 _We see that the export value of the ferro-manganese for the whole period of 1s Years would have been Rs. 17,17.28,730 or £11,448,582. Instead of this 542 MANGANESE DEPOSITS OF INDIA: ECoNOMIcS. [Part III: the export value of the manganese-ore, since it was exported in the raw condition, was only Rs. 3,65,61,913 or £2,437,461; from which we see that India has suffered a loss of Rs. 13,51,66,817 or £9,011,119, or, say, roughly 135 crores of rupees or 9 millions sterling, during the 15 years 1892 to 1906, through not manufacturing ferro-manganese in the country. The loss for the year 1906 alone may be put at 6 crores of rupees or 4 millions sterling ; and for the present year (1907), in which prices for ferro-manganese rule lower, the loss calculated in this way will probably not be less than 14 to 2 millions sterling. The above potential losses considerably overstep the mark, however, for the reason that if all the manganese-ore mined in India were worked up in the country into ferro-manganese, the demand for the ferro pro- duced would not be as great as it is at present for the manganese-ore. For those countries in which there are furnaces set aside for the manu- facture of ferro-manganese would, if deprived of their Indian supplies of manganese-ore, do their best to obtain the ore required from other countries, such as Russia; for the steel companies naturally prefer to make their own manganese-ore and secure the profits on its manufacture, to buying the substance ready-made, when the profits go to some one else. There are, however, many steel manufacturers who do not manu- facture their own ferro-manganese, and these would no doubt be willing to buy Indian ferro-manganese if the price were favourable as compared to that of ferro from other sources. Hence we see that the true potential loss is less than given in the preceding paragraphs ; but how much it is impossible to say. In any case the potential loss to India through ferro-manganese not being made in the country is so large, that the enormous exports of man- ganese-ore year by year cannot be a matter of congratulation to the country. For although they mean employment to some 10,000 coolies, a considerable number of cartmen, a small number of skilled workmen and mining men, and a considerable income to the railways and mine owners, yet each ton of ore that goes out of the country means the loss of a certain amount of employment to men who might be employed in the smelting of the ore into ferro-manganese. Further, each ton of ore that goes out of the country means a smaller amount of ore left against the time when the iron and steel industry becomes a large and flourishing one in India. It would be a great pity, considering how excellently India has been endowed by Nature with many of the materials—iron-ore, manganese-ore, chrome-ore, and wolf- Cuar. XXV.] LOSS TO INDIA. 543 ram,—needed in the modern processes for the manufacture of iron and steel, if, when the time came for iron and steel to be manufactured in the country, it were found that all the subsidiary minerals—manganese- ore, chrome-ore, wolfram, etc.,—had been exported from the country, so that the manufacturer had to import these materials from other countries. I do not want to take up an alarmist position; for there can be no doubt that India has enormous supplies of manganese-ore. Still if the export of this commodity continues at the present rate, the next 20 to 3C years will see the exhaustion of a very large number of deposits, at least as regards high-grade ores. Some deposits already show signs of exhausticn and every year will see more deposits put on to the list of defunct. For- tunately, however, there are signs that the Indian iron and steel industry will get into full swing in the next 10 years, so that it may be in time to take advantage of the existence of manganese-ores in this country. But in the course of the next 20 or 30 years either metallurgical practice will have to be improved so that lower grade and more siliceous ores can be utilised; or, second y, mechanical processes for concentrating and improving these lower grade siliceous ores will have to be adopted ; or, thirdly, the continuity in depth of the high grade ores of the Central Provinces will have to be proved by boring or actual mining ; otherwise the Indian manganese industry will probably come to an end. In the third case the supply of high grade ores would be ensured for a consider- ably longer period than the 20 to 30 years—which is only a guess— mentioned above. With regard to the possibility of manufacturing ferro-manganese in India see page 585. One reason for not advccating at present any restrictions on the export of manganese-ore is that the metallurgy of iron and steel pro- gresses at such a rate that one cannot be certain that the use of manganese may not one day be discontinued in favour of some more efficient substance; or that steel may not be made by some new process in which there is no need for manganese or any substance per- forming similar functions, CHAPTER XXVI. ECONOMICS & MINING—continued. The Mining or Quarrying of Manganese-ores. General principles for deciding whether to mine or quarry a deposit—Mode of occurrence and structure of the deposit—Depths to which manganese-ore deposits extend—Relation of the outcrop of the deposit to the topography—-The value of the ores—Nature of the ‘country ’ of the deposits—The presence of water—Cost of timber, tools, and plant—Cost of labour—Cost of employing technically -trained managers. The way to prospect a manganese-ore deposit. The way to work a manganese-ore deposit—Four mistakes to be avoided—Thick ore-band of moderate dip forming a hill—Thick ore-band of steep dip forming a hill—Thin ore-band in a hill—Thick ore-band cropping out on low ground— Thin ore-band cropping out on low ground—Scattered ore-bodies in lithomarge— Lateritoid cappings—Deposits of detrital ore or talus-ore. To mining men the larger part of this chapter will probably seem trite and unnecessary and out of keeping with the character of the re- inainder of this Memoir, so that an apology for its introduction is perhaps desirable. Now it so happens that there are a large number of people engaged in the Indian manganese industry who have had no previous acquaintance with mining, and consequently in most cases do not recognize the complexity of the problem of working even such an apparently simple thing as a manganese-ore deposit ; according to popular notions, in fact, one has only to dig out the ore, send it to the markets, and draw in the profits. I hope the first section of this chapter will open the eyes of such people and show both them and any other laymen who contemplate taking a part in the Indian manganese industry that to get the best results, and indeed any that are not much below the best, it is necessary to employ men who by training are qualified to deal both with the considerations put forward in this section and with many others not mentioned here. In the section on the way to prospect a manganese-ore deposit, I propose to give a few hints as to the best way in which to obtain some idea of the value of a deposit when found. My object is that if a layman attempt to open up a deposit without proper advice, as is bound fre- quently to happen, his attempts shall be made on some reasonable basis Cuar. XXVI.] MINING V. QUARRYING. RAD so that these preliminary workings shall not be carried out to the detri- ment of the deposit, and force the technically-tramed man, when he comes on the scene, to spend a considerable portion of his time for some months in cleaning up the deposit before he can begin to work it in a systematic Way. In the third section—on the way to work a deposit—I propose to indicate roughly the outlines of the methods that it seems to me could be adopted with the best advantage when it comes to actually working the deposits. I have not gone into any details, both on account of the space it would take up and because each deposit is realiy a problem in itself with regard te details. ‘This section will, I hope, be of use even io the qualified miner ; for on coming to a new country he is not likely to be able to grasp at once the true structure and mode of occurrence of the deposits,and his employers are not asa rule likely tolet him sit down and find this out in a satisfactory way, unless he can contrive to do it in company with a large output of ore, and a small expenditure. The figures illustrating this section practically all represent, as regards mode of occurrence, deposits that actually exist. General Frinc.ples for Deciling whether to Mine or Quarry a Deposit. It may be laid down as an axiom that in working any given mineral deposit that method should be chosen that will give the maximum profit per ton of ore extracted ; the profit being of course, in the case of ores that are exported in a raw condition, the difference between the total costs of extracting the ore and putting it on the market, and the price it will fetch on that market; or, in the case of ores that are to be smelted or otherwise worked up on the spot, the difference between the total costs of extraction, smelting or preparing, and transporting to the market, and the price the treated product will fetch when it reaches the market. Tn calculating the maximum profit obtainable from a given deposit, however, it is necessary to consider the whole of the merchantable ore that the deposit may be known to contain, or that it 1s possible that future development may prove it to contain; that is, it is necessary to consider the life of the deposit. Now the chief factors that have to be considered in deciding in what way to open up a given deposit are the following :— (1) The mode of occurrence and structure of the deposit. (2) The relation of the deposit to the topography. 546 MANGANESE DEPOSITS OF INDIA: MINING. [ Part IIT: (3) The value of the average ores of the deposit, and of the best ores. (4) The character of the ‘country’ of the deposit, as regards both the soundness of the rock and the abundance of water. (5) The costs of mining materials, such as timber, tools and plant, when delivered at the mine. (6) The cost of labour, both local and imported. (7) The cost of employing men with knowledge sufficient to develop the deposit in the way proposed. The two chief methods of working a mineral deposit—leaving’ out of account detrital and alluvial deposits, which may be treated by dredging, hydraulicking, etc.,—are :— (a2) Opencast working, or quarrying. (>) Underground working, or true mining. We can now consider the influence of each of the above factors in determining the way in which manganese-ore deposits in general, and the Indian manganese-ore deposits in particular, should be worked. 1. It is obvious that if the body or bodies of ore lie at or close to the surface, with no or very little overburden, Pre ee Oy tet opencast work, or quarrying, is all that will be necessary. If, however, the ore-body, in the form of either bed, lenticle, vein, or irregular mass, extend to some considerable depth, it will be necessary to resort to the methods of underground mining to win, at any rate the deeper portions of, the ore. If it be decided that it will pay to win the ore lying below the depth to which opencast working can be carried, it will be necessary to decide whether the whole of the ore-body is to be mined, or whether the upper portion is to be quarried and the lower mined. It is also obvious that before any proper decision can be reached on these points it is necessary to know something about the structure of the deposit. This can of course be obtained only by testing the deposit, first by means of surface prospecting, involving the digging of surface cross-cuts or costeans, and trial pits ; and then, if the ore be found to go to as great a depth as can be conveniently reached by these methods, by putting down shafts or bore-holes. It has yet to be proved that deposits of manganese-ore extend to a greater depth from the surface than a few _Depths to which mangan- hundred feet, say 300 to 500 feet (many of course ese-ore deposits extend. do not extend to greater depths than 50 feet Cuar. XXVI.] MINING V. QUARRYING. 547 or Jess). In fact the mining and quarrying of manganese-ore deposits in different parts of the world has shown that the deposits of oxide-ores have been formed, in the majority of cases, at or close to the surface, and do not extend to any considerable depth, say beyond 50 to 500 feet. It is to be noted, however, that if any portions of the ores of the Central Provinces of India can be considered as the product of the direct compres- sion of original manganese-oxide sediments, then such portions may be found to continue to as great a depth as the associated rocks of the gondite series, and this may bein some cases considerably more than 300 to 500 feet. The same remarks apply to any other deposits, such as those of Sweden, that have been formed by the direct compres- sion and metamorphism of original manganese-oxide sediments, without any passage through a silicate stage with subsequent chemical alteration. (The franklinite deposits of New Jersey in America, in which the frank- linite, a manganese-zinc-iron mineral, is regarded by some as having been formed by the metamorphism of original sediments containing both manganese and zinc, and which has been proved by boring to continue to depths of over 1,000 feet, may be citedas an example of a man. ganese-oxide mineral proved to continue to a great depth.) Even on the assumption that none of the Indian deposits wili be proved to continue to a greater depth than 300 to 500 feet below the original outcrop, there is still plenty of scope for true mining ; namely, between the depths of 50 to 100 feet and 300 to 500 feet. Before passing on to the next section I will state the depths to which the Indian manganese- ore deposits have been proved, and may be expected to continue. TABLE 87. Depths to which Indian manganese-ore deposits extend. | Depth to which 5 ae Depth to which may be expected vent which aan proved. | in some cases to P y se rae cases continue. Feet Feet. Feet. Central Proyiaces : 2 20 | 150—290 200—500, or : more. Vizagapatam : : : 100 150—200 300—490 Sandur . : - ° 50 80 100 Mysore 2 : : = || 30 60 80 The figures given in the first column refer only to the larger deposits. Tu some cases in each area deposits have been found not to centinue even to the depths given in this column. Those in the second column 548 MANGANESE DEPOSITS OF INDIA: MINING. [Parr IIL: also apply to the larger deposits in each area, such as Kandri, Kodur, Durgémma Kolla, and Kumsi, typical of each of thefour areas men- tioned. The figures given in the third column may be regarded as the probable outside limits to which the most extensive deposits in each area may possibly extend. It must be remembered, however, that these figures are based on theoretical guesses, in the absence of any bore holes or shafts proving the deposits to continue to any greater depths than in the first column. 2. The position of the outcrop of the deposit with regard to the Relation.ofake outetp topography of the surface is also a matter of some of the deposit to the topo- importance. Thus it might be possible to work a braphy- deposit outcropping ona hill 200 feet high with reference to the surrounding plains, and proved by boring or other methods of prospecting to continue to a depth of 200 feet from the top of the outcrop, entirely by opencast work, given favourable cireum- stances as to the nature of the ‘country’: whilst a deposit, the top of which only just appears above the surface of plain country, and also proved to extend to a depth of 200° feet below the outcrop, could be worked by opencast work to adepth of some 100 feet only, except by carrying out an enormous amount of deadwork; in fact, except at enormous expense, or in most exceptional circumstances, it would be necessary to resort to mining to extract the second hundred feet of ore. 3. If an ore deposit extend to a considerable depth so that deep mining wil! be necessary to win all but say the top 100 feet of it, then the value of the deeper ore decides whether it will pay to follow it to thisdepth. It has already been noticed that in all probability deposits of manganese-oxide ores, with possibly a few rare exceptions, do not extend to greater depths than 50 to 500 feet. Andit is doubtful, considering the comparatively low market value of manganese-ore, whether it would pay to follow a manganese deposit below the depth of 300 to 500 feet, even if it continued. The necessary conditions for it to be workable below this depth would probably be that the deposit should be a thick, regular deposit of high- grade ore situated close to the smelting centres. But let us confine our- selves to ores lying at depths less than this 300 to 500 feet. It is obvious that the average quality of the ore would have a considerable bearing on the vossibility of extracting that portion lying at depths greater than 50 to 100 feet. Thus near the surface with favourable conditions it might easily be possible to extract ore of very low grade, say 20 to 30 per cent. of manganese, and treat it mechanically so as to concentrate The value of the ores. Cuar. XXVI.] MINING V. QUARRYING. 549 it up to a marketable grade ; whilst at depths below this 50 to 100 feet, but otherwise under the same conditions, it might not be possible to work cre that was not of fairly high grade, and required mechanical treatment to render it marketable. Some manganese-ore deposits contain bands of ore requiring mechanical treatment to render them fit for the market, alternating with bands of ore not requiring such mechanical treatment. In sucha case if an average sample of the whole width of the ore-body were taken at a depth of 100 feet, the assay result might indicate that the deposit could not be profitably worked at such a depth. Whilst if the poor and rich ore were analysed separately it might turn out that it would pay to work the deposit at this depth by rejecting the lower grade ore. It is possible to imagine the case of two manganese-ore deposits, the average ore of which taken from a depth of 100 feet assayed 35 per cent. manganese in each case. But on account of the ore of one being uniformly of 35 per cent. grade throughout, a considerable proportion of the remainder being quartz, it might be unprofitable to work it, on account of the cost of treating the ore mecha- nically in order to fit it for the market. On the other hand, the other deposit, being composed of bands of ore of variable composition, some as high as 50 per cent. manganese, and some as low as 20 to 30 per cent. manganese, might possibly be workable at a profit by saving only the higher grade ore, and rejecting the remainder, so as to avoid the cost of mechanical concentration. 4. The character of the ‘country’ or enclosing rock of the ore : _ deposit is also a matter of considerable import- Nature of the ‘country ae eiileeepent. “ance. In cases where it is extremely soft and wet, as in the case of the lithomargic ‘ country ’ of Kodur and other mines in the Vizagapatam district, it might be a matter of extreme difficulty and danger, with very high working costs, to mine the deeper portions of the deposit; whilst on account of the ex- treme softness of the ‘country’ it might be possible, by carrying out an enormous amount of deadwork, to work opencast to a much greater depth than would be possible with hard ‘country’, ata cost much lower than that of true mining ; the quarry would be very much wider than the width of the ore-body, and would have its sides stepped on account of the softness of the ‘country’; and the soft ‘country ’ would be removed in slices as the quarry was constantly deepened. Such is the practice that has been followed in the case of the Kodur quarry in Vizagapatam, which has now reached a depth of about 100 feet below the original surface of the plains. Such a method of work 550 MANGANESE DEPOSITS OF INDIA: MINING. [Part III: would, however, be prohibitive in cost and unnecessary, were the ‘country’ hard and sound. On the other hand, the soundness of the ground would reduce the cost of true mining on account of the smaller cost of timbering required, and might make mining cheaper than quarrying. The presence of water in a deposit is also of great importance. One of the reasons why it is possible to work to greater depths opencast on a deposit situated on a hill, than on a deposit the top of which is only at plains level, is that the former deposits are usually comparatively dry, and if not they can be easily rendered so by the construction of drainage adits driven into the side of the hill. Pumping, when necessary, may be a serious item in the total costs cf mining. 3. In cases where it is doubtful whether to quarry or mine a deposit the relative costs of the tools and plant required in the two cases, and the cost of the timbering that may be required in case underground mining is resorted to, have to be considered. 6. When labour is very cheap it may often be advisable to work a deposit ina simpler way and with less labour- saving apparatus than would be desirable in the case of dear labour. India is a country of cheap labour. But it must be remembered that besides the cheapness of labour, as measured by the wages per head paid, the efficiency and abundance of the labour has to be considered. Though the amount of ore or coal excavated per man per day is considerably less in India than with European labour in colder climes, yet the greater expense of the white labour probably overbalances the extra efficiency. [In coal mining it is probable that no country works more cheaply than India.] Further, if a supply of labour cannot be obtained sufficient to keep a mine in full swing, as often happens in some of the manganese-mining districts of India, then in spite of the relative cheapness of such labour as is obtainable it may still be desirable to make use of as much labour-saving apparatus as possible. In considering the respective merits of quarrying and mining in the case of a deposit extending to such a depth that it might be treated in either way, it has to be remembered that for underground work a greater proportion of skilled labour is necessary than for opencast work. It then usually happens that the labour for underground work has to be trained, or to be imported from elsewhere at a higher rate than would obtain for local labour employed for opencast work. The presence of water. Cost of timber, tools and plant. Cost of labour. CuaP. XXVI.] PROSPECTING a DEPOSIT. 551 7. A further point that has to be considered is that opencast work can be carried out with a smaller amount of skilled supervision than underground mining. In fact itis often the custom in India—though this is most undesirable from the point of view cf the life of the deposit, and therefore of the good both of the country and of the individual or com- pany to whom the country has entrusted the development of the deposit —to open up a deposit, extract the ore in large quantities, and export it, without having any technically-trained man or men to superintend and direct the work. Without the technically-trained men noticed under heading 7, it is of course impossible for the licensee or lessee of a property to ascertain anything accurate about the mode of occurrence of his deposit, and about its structure, and therefore impossible to work the deposit in the most advantageous way. Cost of employing tech- nically-trained managers. The Way to Prospect a Manganese-ore Deposit. Let us suppose that one has found a loose piece of manganese-ore either in a stream-bed or on a hill-side. One goes of course upstream, _or uphill, as the case may be, to see where the fragment has come from. As likely as not the prospector will be rewarded by finding other pieces of ore in increasing quantities, and will finally arrive at an outcrop of manganese-ore in situ. This outcrop may be an isolated one projecting through alluvium or soil, and showing no indications of strike or dip, €-9-, O in figure 28. The soil should then be removed to a depth SCALE:-9 0 20 30 40 SO 60 FEET Fig. 28.—Prospecting an o tcrop on low ground 552 MANGANESE DEPOSITS OF INDIA: MINING. [Part III: of a few feet, for a distance of some yards in all directions round the deposit, such as up to the circle in the figure. Further indications of ore will then probably be found, such as the cross-hatched areas in figure 28. These will probably show some signs of direction; in the figure they indicate a strike AB. A trench, CD, should then be dug at right angles to this supposed strike, and carried down to a depth sufficient to show both the full width of the ore-body, and its contact with the ‘ country ’ or enclosing rocks. From the boundaries of the ore- band as seen in the trench, it will probably be found that this first trench has not been dug exactly at right angles to the strike of the ore-body, but askew. Another trench, such as EF in the figure, should then be constructed in a direction at right angles to the supposed strike of the ore-body, and for the purpose of testing the extension of the ore-body in this direction. It will probably be found necessary to dig this trench deeper than CD in order to reach rock in situ, for, as likely as not, the original outcrop corresponds to a small hill or hillock submerged in the alluvium. With this second trench the true strike of the ore-body should be ascertained ; and the width of the deposit will now be known at two points. The extension in both directions should now be tested by further trenches both to the right and left of the original ones. Possibly, however, there may be several small outcrops ranged along a low ridge some 30 to 100 feet high, or along a higher range or hill from 100 to 300 or even 500 feet high. In this case the length of the ridge probably corresponds with the strike of the ore-body, at least roughly. Figure 29 may be taken to represent a ridge about 100 feet high, showing ee SCALE:- Fig 29.—Prospecting an outcrop along a ridge Cuap. XXVI.] WORKING A DEPOSIT. 553 several small outcrops (black) arranged along the crest of the ridge. Possibly the outcrops will show signs of a dip, if the ore-body be a sheet- like mass. Whether it does or not a series of trenches should be cut across the ridge at regular intervals. There is no necessity to carry them down to the level of the plain round the hill, but they should be carried down deep enough to reach rock everywhere. From this series of trenches it will be possible to ascertain the true strike of the ore-body, its dip—probably varying from point to point—, and the width at several points, from which an average of some value can be struck. Other trenches should be put across the assumed extension of the deposit on the plains at either end of the ridge to test the continuation of the deposit in both directions. One of the trenches on the hill itself might be cut down to a depth of at least 30 feet, in order to show that the deposit extends to at least this distance. It may be objected that the trenches shown in figure 29 are much too long, considering the width of the ore-band. It must be noticed, therefore, that both slopes of the ridge would probably be covered with talus-ore and these trenches would therefore indicate the quality and quantity of such ore available, and, moreover, reveal any subsidiary ore-bands, should such exist, as is not infrequently the case. It may happen that the outcrop takes the form of a more or less horizontal capping on the top of a hill, with the ore not extending down the sides. A trench or trial pit carried to a depth of 20 to 50 feet—or an adit driven into the edge of the capping some 30 feet below the top—will then probably show a passage down into rock that is too poor in manganese-ore to be workable; and in such a case, as is so common in Mysore, it will probably be useless to look for ore on the low ground surrounding the hill, or on its sides, except in the form of detritus derived from the ore in situ on the top. This case is illustrated in figure 35. The Way to Work a Deposit. It is not to be supposed that the information gained in the way ‘described above, valuable though it be, is necessarily all that is required before work can be started on rational lines. If it has revealed the existence of large bodies of ore near the surface, then there can be no doubt that the deposit should be opened up as a quarry. If the pros- pecting has revealed the fact that the deposits are of a superficial charac- ter, as in the case illustrated in figure 35, there is then also no doubt that the deposit is a quarrying proposition. But supposing that the opera- tions have shown the presence of a band of ore of good quality, but ot Ill K 554 MANGANESE DEPOSITS OF INDIA: MINING. [Part IIT: small width, say only 5 feet thick. Such a deposit could of course be opened up as a quarry. But it would be much better to ascertain if the deposit extend to any depth, either by a small prospecting shaft, calculated to strike the ore-band at 100 feet, by a small incline shaft on the ore, or by means of boreholes calculated to strike the deposit at depths up to 300 feet. For it would not be economically possible to follow such a thin band to a great depth by quarrying, on account of the enormous expense of the earthwork that would have to be done; and if mining were necessary it might be better to start straight away on it. This case is illustrated in figure 33, which might well be taken to represent the Gowari Warhona deposit in the Chhindwara district. There must also be many deposits of characters intermediate between the large bodies of ore referred to above, and the thin band found at Gowdri Warhona. Hence it is evident that in many cases it would be advisable to wait before opening up the deposit as a quarry, until it has been ascertained whether the ore go to any considerable depth or not, and then to decide if it would not be better to mine the deposit, instead of quarrying it. I suppose, however, it is useless to mention this point, because the owner of a manganese-ore deposit always wants money returns with the greatest possible speed, and can never wait to have the deposit properly developed. However, by following the ore on an inclined shaft it is possible to prove the ore and win ore at the same time. Having determined the character of the deposit, at least to the extent of finding out something about its width, strike, and dip, and whether any considerable amount of ore be available, the operator can think about opening it up. If quarrying be decided upon then there are four main points to be Four mistakes to be Observed if the deposit is to be properly avoided. worked. These are :— 1, The waste must not be dumped on the line of strike of the deposit. 2. The waste must not be dumped too near the sides of the deposit, assuming it to be longer in one direction than in the other; and by preference the waste should be dumped on the side away from which the ore is dipping and not on the dip side. The distance to which the waste should be carried depends on the angle of dip of the deposit, and on the depth to which it is likely to be worth while to follow it by opencast work. The flatter the dip, the wider will the quarry have to be for the ore to be extracted down to a given depth, say 100 feet ; and the Cuap. XXVI.] THICK ORE-BAND IN A HILL. 555 deeper to which it is worth while to follow the deposit, the wider will be the workings necessary for opencast work. C 3. The work of extracting the ore must be SEEDED Ces. by a suit- able amount of deadwork, i.e., extraction of the ‘country’ or wall-rock on either side of the deposit. Otherwise the workings will tend to take the shape of an ever-narrowing groove, from which it will be increasingly difficult and dangerous to extract the ore. 4, Care should be taken when constructing buildings or tramways not to put them in places from which it may afterwards be necessary to remove them; such as on top of an extension of the ore-body, or where they interfere with the proper working of the deposit. The above remarks may seem to be trite. But all the principles there mentioned have been broken again and again in the course of Indian manganese mining, usually through ignorance of the structure of the deposit being worked, and an eager attempt to obtein as much ore as possible without any regard for the future; but sometimes, in cases where a qualified man is employed, because the management of the syndicate or company will not provide the funds required for the rational development of the deposit. I now take a few typical cases and give roughly what seems to me the best method of opening up and working" the deposit in each. Figures 30 and 31 can be taken to represent cases found fairly é often in the Central Provinces, in which a bed- Thick ore-band of moder- . - - : : ate dip forming a hill. like ore-body gives rise to a small hill, of which it forms the backbone. We can suppose that in each case the ore-body has been shown by the preliminary cross trenches, _® so Ino 200 300 FEET Fig 30.— Quarrying a thick ore-band of moderate dip in a hill, ITt K 2 556 MANGANESE DEPOSITS OF INDIA: MINING. [Part III: constructed as illustrated in figure 29, to be of considerable thick- ness, say 50 feet. In figure 30 it is shown dipping at an angle of 40°, and in figure 3] at an angle of 80°, the slope of the hill on the dip side of the deposit being in each case about 30°. We can also suppose tnat the hill is in each case about 300 feet high as referred to the low ground at the base. The difference in the dip of the deposits may produce a radical difference between the methods of work to be adopted in each case. In the case illustrated in figure 30, there is little doubt that the deposit should be quarried, at least down to the level of the low ground. This quarrying could probably be most systematically carried out by working the deposit in horizontal slices of a convenient thickness, say 50 feet—AA’, BB’, CC’, etc., in figure 30. Work should be started at the summit of the hill with the removal of the overburden AA”O along the whole length of the ore-body down to the level of the bottom of the first 50-foot slice, AA’. On AA” a levelor bench should then be constructed parallel to the whole length of the ore-band, and tram lines laid down. Toremove the ore to the bottom of the hill on the dip side, gravity inclines (tramways) or aérial ropeways, one or more according to the length of level A, should be constructed, with the loading station just below level A, so that the ore in the trucks on this level could be tipped direct into the trucks or buckets of the incline or ropeway. With the slope of the hill given, inclines would probably be better than ropeways; an incline also has the advantage of a greater carrying capacity than a ropeway. From level A the waste should be run out on to the scarp side, OF’, of the deposit, through openings made by deepening the original prospecting cross-trenches down to the 50-foot level AA’. It would be advisable to start work on the out- crop, O, before the level A and the incline are finished, so as to have a supply of ore ready to despatch to the bottom of the hill at the earliest possible moment. With the level A constructed and the dip slope OA” of the ore-band exposed, it would be an easy thing to remove the ore down to the level A and transport it expeditiously to the foot of the hill. It would probably be advisable to remove the country on the foot- wall side also of the deposit down to the 50-foot level. It would be as well to arrange to work away the first slice of ore sooner at one end of the deposit than at the other, so as to allow the removal of the country AA” B’B and the preparation of level B at this end before the ore had been completely removed from the other end of level A. Arrangements would have to be made for moving the loading stations of the inclines down slice by slice as the work progressed. In this way work would be Cusp. XXVI.] | ~—s- THICK ORE-BAND IN A HILL. 537 carried down slice by slice as long as the work of removing the ‘ country ’ on the hanging-wall side of the deposit did not become too expensive. This would depend on the relation between the slope of the hill and the dip of the deposit as the base of the hill was reached. It might be neces- sary in case the slope of the hill became very small to extract the last slice or two by means of a trough-like quarry, instead of removing all the ‘country’ on the hanging-wall side at this level. As regards the ‘country’ on the foot-wall side, this would probably have to be removed only for a few feet back from the foot-wall of the deposit, in a stepped fashion as illustrated, the stepping being for safety’s sake, except in the case of very sound ‘country’. As regards the disposal of the waste, it would probably be too expensive to send it to the scarp side of the deposit, after the first two slices had been worked, unless there happened to be a neck somewhere along the ridge through which a level for the waste could be run. Further, those portions of the waste derived from the workings towards the ends of the ridge could be run round these ends to the scarp side. But the waste from the middle portions of the ridge would probably have to be taken down the inclines on to the low ground on the dip side of the deposit. The above is given as a method suitable for a big thick deposit. The Balaghat deposit is an example of a deposit that is being worked after this method, with the modifications necessary to adapt it to the configuration of the ground. In the case of smaller deposits suitable modifications would be introduced ; but the general plan should be based on the above. In figure 31 we have a case similar to the above, except that the deposit dips at a much steeper angle (80°) than that Cir talaga steep of the hill (30°). This should also be worked in slices ; but owing to the expense of removing the much increased amount of ‘ country ’ on the hanging-wall side of the Fig. 31.—Miningor quarrying a thick ore-band of steep dip in a hill. 558 MANGANESE DEPOSITS OF INDIA: MINING. [Parr ITI: deposit, it would probably not pay to remove more than one or two 50- foot slices in the way illustrated in figure 30. If the ‘ country’ were very sound and tough, it would probably be cheapest to remove the top 100 feet of the ore by means of an open quarry, as indicated in figure 31, but less wide, and then to drive in tunnels along the strike of the ore-band at the 200-foot and 300-foot levels respectively, and to first stope out the ore from the 200-foot level up to the 100-foot level, removing the ore through the 200-foot tunnel, and to treat the next slice in the same way, remoying it through the 300-foot tunnel. [During 1907 a beginning has been made to mine in this way the portions of the Mansar deposit lying below the 100-foot level.] These tunnels would also serve for drainage. In the excepticnal case of the ore-band not running the whole length of the hill so that it did not crop out at the two ends, it might be cheaper to drive the cross-cut tunnels B, C, and D, as in figure 31, instead of tunnels on the strike. If. however, the ground were very soft and decomposed it might be easier to continue the quarrying system as indicated by the stepped lines, representing successive stages, down to the base of the hill. Arrangements would have to be made for draining the quarry, probably through the two ends of the ridge. In fact the free drainage of the deposit could to a certain extent be secured by working the ends of the ridge quicker than the middle and so keeping them at a lower level. But whether the ore down to the base of the hill were quarried or mined there is no doubt that mining would have to be resorted to, in order to follow it any deeper, should it continue. It is, of course, only if the ore-band were fairly thick that it could pay to quarry the deposit by removing the whole six slices as in figure 30, or by making a wide quarry, as in figure 31. If the ore-band were thin, say only 5 to 10 feet thick, then it would probably be found that the only economical way of recovering all except the top 50 feet would be by mining the deposit like a mineral vein, as indicated in the previous paragraph for the case of asteeply dipping band of considerable thickness, with sound ‘country ’. Thin ore-band in a hill. We now come to the case illustrated in figure 32 of a fairly thick _ ore-band, the outcrop of which is on low ground. panes pane eps Fa: In this case it does not make much difference whether the angle of dip of the deposit is mode- rate, as represented in the figure, or whether it is steep, say from 70° to Cuap. XXVI.] THICK ORE-BAND ON LOW GROUND. 559 30° (vertical). In either case it would probably be better to open up the Fig. 32.—Quarrying a thick ore-band cropping out on low ground. o deposit as a quarry, with stepped sides as indicated in the figure, the stepped lines indicating the approximate positions of the sides of the quarries for different depths. The difference introduced by the different angles of dip is that with a shallow dip more ore can be won down to a given depth than with a steep dip, the most favourable condition as regards dip being the one in which the ore-band is folded so as to be kept at the surface for a considerable distance across the strike, as at Kajlidongri (Plate 19). The depth to which such an open quarry could be carried, supposing the ore to continue, depends on a variety of condi- tions, of which the chief is probably the character of the ‘country’ or wall-rock of the deposit. It might conceivably be carried to a depth of 150 to 200 feet ; but it is probable that before this, except under exceptional circumstances, such as great thickness of the ore-band, accompanied by very high quality, it would pay better to start mining the deposit, by the ordinary methods applicable to veins. It will be seen that if worked as illustrated in figure 30 in the case of a hill deposit, or as in figure 32 in the case of a plains deposit, the side of the quarry on the foot-wall side would keep moderately close to the foot-wall side of the deposit. In these cases it would be as well to drive one or two tunnels into the foot-wall side in order to ascertain whether a second ore-band be present, as might easily be the case, and as is illustrated in figure 32. Or of course the same could be tested by boring. In the case illustrated in figure 33, in which the ore-band is supposed mane Vo 1s. J) to be only 6 feet thick, and to crop out on low out on low ground. pps ground, there is little doubt that if the deposit continue to any considerable depth, and it be 560 MANGANESE DEPOSITS OF INDIA: MINING. [Part III: desired to win the ore down to this depth, the deposit should be treated Fig. 33.—A thin ore-band cropping out on low¥ground. like a mineral vein from the beginning, and worked by inclined shafts following the dip of the ore, and stoped right out. The deposit at Gowéri Warhona in the Chhindwara district, Central Provinces, is a case in point. The dip of the deposit is about 50° as seen in néla sections, and its width is 54 to 6 feet. The depth to which the ore extends is as usual unknown ; the proper way to treat this deposit would be first to bore it and see to what depth workable ore extends. It might only be tested to depths of 150 to 200 feet at first. Then, if the ore were found to extend to only 50 feet or a little more, calculation might show that it would be cheaper to quarry the deposit. But if the ore were proved to continue to 100 feet or more, then calculations would probably show it to be a case of either mining the deposit or leaving it alone altogether. It would not be a fair thing to extract what could be won by opencast work and abandon the remainder. The deposit should therefore either be mined, or let alone altogether until such time as animprovement of communications or prices allow the deposit to be mined. From figure 33 it can be seen how expensive it would be to quarry down to a depth of 100 feet. To win the ore DE between the 80-foot and 100-foot levels, it would be necessary to remove all the ‘country’ EE’ D’D; and the deeper the quarry became, the larger would be the amount of dead work necessary to win each 26 feet of ore measured on the dip. We can now consider the case represented in figure 34, which may be taken as a generalized expression of the condi- tions obtaining in some of the Vizagapatam deposits, although in these deposits there is usually some sign of arrangement of the manganese-ore bodies parallel to Scattered ore-bodies in lithomarges. Cuap. XXVI.] ORE-BODIES IN LITHOMARGE. 561 the boundaries of the rock in which they are situated. Let us suppose that workable ores continue to a depth of 300 feet as indicated and that they are scattered through soft lithomargic rocks. The original outcrop is shown at O. The ore-body of which this is part has been worked by 4 <-------~-~--300------------- Fig. 34.—Scattered ore-bodies in lithomarge. means of a large quarry, and found to terminate at a depth of about 100 feet. In quarrying this large mass, however, several small concretions and pockets of ore have been found scattered through the surrounding soit lithomarges. Now it is obvious that if the quarry be abandoned with the idea that the ore has come to an end a great mistake will be made, several times as much ore as that extracted being left in the ground. The obvious point is that the subsidiary concretions and pockets should be taken as a warning, and the surrounding rock explored. Mr. T. Caplen tells me that at Kodur he has found putting down small bore-holes with a percussion drill avery successful method of proving the existence of scattered bodies of ore. Tunnels driven horizontally from the sides of such a quarry wouldalso he of great value, as illustrated by B, C, and D, in the figure, two of them striking ore and one missing it. Having proved the existence of these scat- tered ore-bodies to a depth of 300 feet, it is a very difficult question to settle how to win this ore, considering the softness of the rocks in which it lies. It is obvious that to make sure of missing no body of any size it would be necessary either to remove the whole of the rock from 562 MANGANESE DEPOSITS OF INDIA: MINING. [Parr IIT: the ore-bearing area, forming an enormous quarry of great depth, or to mine the lower portions of the deposit, driving a large number of bore holes to find where the ore-bodies lie. Such a process of mining would need very expensive timbering on account of the softness of the ground, and would be very uncertain, with the probability of leaving undiscovered in the ground a considerable proportion of the ore. A similar problem has arisen at Crimora in Virginia, where the manganese-ore occurs as concretionary nodules and pockets scattered through clays occupying a basin over 200 feet deep. This occurrence has been tackled at different times by means of shafts and open pits ; the former method was found to be so uncertain that it has been lately decided to hydraulick the whole deposit, as described on page 575. The Vizagapatam deposits are not however suitable for this treatment, in the first case because it would rarely be possible to find lower ground close at hand on to which the water from the hydraulicking could run, and secondly because the proportion of small concretions in the lithomarge is small compared to the more massive ore-bodies, which are usually of much too large a size to be amenable to such treatment. It might be possible in rare cases to treat Indian deposits by hydraulicking, but I cannot point to any good example. Hence it is an alternative between mining such deposits as Kodur below the 100-foot level, this being uncertain as to finding all the ore, very expensive on account of timbering, and not improbably dan- gerous ; and continuing the quarrying to depths greater than 100 feet (a depth already reached at Kodur). It will probably be found neces- sary to continue the open quarry system to still greater depths than have at present been reached and then either to abandon the deposit or attempt to win as much as possible of the remaining ore by underground mining, at times when the market is high. The next case to be considered is that illustrated in figure 35. It represents a capping of mixed manganese- and iron-ores of lateritoid aspect,! such as is often found in Mysore. These deposits do not continue to any depth, for they have been formed by the superficial replacement of quartzites and phyllites and pass irregularly down into these rocks through a zone of decomposed and partly replaced rock. The thickness (7.e,, depth) of the deposits is Lateritoid cappings. 1 For the meaning of this word see page 382. Cuap. XXVI.] LATERITOID CAPPINGS. 563 in all probability rarely greater than 30 to 50 feet, and hence the problem Lithomarge and altered quartzite Fig. 35.—A lateritoid capping. of working them is a simple one. It consists in removing the whole ca p of the hill wherever it shows a sufficient proportion of manganese-ore. The waste can be thrown down the slopes in any direction, once the loose deposits of detrital ore, derived by denudation from the cap and lying on the slopes, have been worked over. When the underlying soft rocks have been reached, itis hopeless to expect any continuation of the deposit at greater depths, except perhaps for a few isolated pockets scattered through the soft ithomarges (or decomposed quartzites), the form usually taken by the decomposed rock immediately underlying the manganese-ore of the cap. The point then to be settled by the operator is whether it is worth his while to turn over this soft lithomarge in search of isolated pockets, or whether it is better to leave such pockets in the ground. To do the latter would not be a matter of much concern to the Government; for the quantity of ore so lost would be small; but it is probable that at times of high prices it might pay to work over these soft lithomarges in cases where the indications look favourable. The last type of deposit to be considered is that illustrated in figure 36, a ene namely the deposits of detrital ore, to which I Pas ae : have usually referred in this Memoir as detrital ore or talus-ore but which is usually termed boulder-ore or float-ore by the mining community. These detrital deposits are formed by the denudation of deposits in situ and are usually to be found on the slopes and at the foot of hills showing an outcrop of manganese-ore, being as a rule best on the scarpside. In the case, algo, 564 MANGANESE DEPOSITS OF INDIA: MINING. [Parr III: of deposits that crop out on low ground there is usually a covering of OPEN oi tee | oy "25 7. Os I Sea wd @ 2 DETRITUS Pipe as mee ato | TM - Fig. 36.—A detrital or talus-ore deposit. detrital ore a few feet thick. In many cases these detrital deposits have to be worked in the course of opening up the ore-body in situ. But this is not always the case. Thus, in the case shown in figure 30 on page 555, there would in all probability be a considerable quantity of detrital ore on the scarp slope OF’. Before throwing down this slope the waste from uncovering the ore-body in situ, all the detrital ore should be worked over. This is not a counsel of perfection ; for it often happens that considerable quantities of good merchantable ore may be quickly won at a small cost from the detrital deposits ; and the income derived from such may be a great help to the hard-pressed manager by allowing him to give his company an immediate output of ore, and leaving him some time to open up the deposit 2m situ in a rational way. It is also worth noticing that some in situ deposits, namely those formed at the surface, show a progressive deterioration with depth, the best ore being that immediately at the surface. From this it follows that in many cases the ore found in the detrital deposits, having been formed by the denu- dation of the uppermost portions of the ore-body in situ, must be of a better quality than that»found in the latter. Even in working over detrital deposits, in which the ore fragments occur in variable abundance, and usually in a matrix of clayey, loamy or gritty soil, it is well to employ some system. I had the difference well illustrated at the deposits situated near Shiddarhalli, in the Shimoga district. In both cases I am referring to detrital deposits consisting of loose fragments of ore scattered through a clayey or loamy soil to depths up to 10 feet or a little more, and lying on comparatively level ground at the base of hills from which the ore had probably been derived. In the one case the deposits—those situated in the Kadur district, Hadikere village limits, just over the Shimoga boundary, and east of Shiddarhalli—had been worked anyhow. Pits had been dug here and there and the waste from the extraction Cuar. XXVI] TALUS-ORE DEPOSITS. 565 of the ore dumped immediately by the side of the pit, usually on ore- bearing ground not yet turned over, and the whole then abandoned, though it may be but temporarily. To win the ore now covered up will cost more than if the waste had been carried to a safe distance ; and in some cases the cost of removing this overburden will doubtless be considered too great to permit of the working of the ground under- neath. In the other case, in a deposit lying to the south-west of Bale- katte and north of Shiddarhalli village, the ground had been divided into strips 5 or 6 feet wide as illustrated in figure 37. Alternate strips A were being worked. The method adopted was to excavate the C end of the strip to as great a depth as was considered payable—some 5 or 6 feet in this case—and remove the waste from this to a safe distance. The remainder of the strip was worked over by men advancing from C towards A and pulling down with kodalis, into the cavity already made, the ground in front of them. In this way they worked along the whole strip, extracting the loose pieces of ore as they turned them > Fe A A ’ Y Fig. 37.—Systematic plan of working detrital deposits. up, and raking the loose soil behind them, women being employed to remove a certain proportion of this soil so as to keep the trench sufficiently open. When the A strips had been worked over, then the 8 strips were to be treated in the same way. The reason for working alternate strips was probably the convenient disposal of the ore won, and the convenient access of the coolie women who removed the ore and waste. It struck me that this was the best and most systematic method I had yet noticed of working detrital deposits. It must be observed that in this case the only object was to win the loose frag- ments of ore, for there was no reason for supposing that the detritus overlay manganese-ore im situ. In the latter case,it would have been necessary to remove all the soil to a distance. These detrital deposits, when of large extent, would seem to be admirably suited for treatment on the lines of the Northamptonshire iron-ore deposits, i.e., by working 566 MANGANESE DEPOSITS OF INDIA: MINING. [Part IIT: with a long working face and tramlines that are moved forward every time a slice of ore of given width has been removed from the whole length of the face. In the foregoing paragraphs I have attempted to indicate roughly the methods that seem to me to be most applicable to the working of the various types of manganese-ore deposit. There are many departures from the above types, and each departure introduces a modification in the precise method of tackling the deposit, CHAPTER XXVII. ECONOMICS & MINING—continued. The Mining or Quarrying of Manganese-ores—contd. The methods actually used in working the Indian manganese-ore deposits—Indian Manganese quarries legally mines—Classification of deposits—Brief description of method of working Indian deposits—Gravity-inclines and ropeways—Mining tram ways and railways—Sampling—Deposits often badly worked—Waste of smalls and dust—Waste of low grade and siliceous lump ores—Possibility of washing, concentrat- ing. and briquetting, smalls and fines. Methods of mining, concentrating, and briquetting manganese-ores used abroad—Bri- quetting in Brazil—Hydraulicking and washing in Virginia—Mining, washing, etc., in Panama—Mining of manganese deposits in other parts of the world. The grant of mineral concessions in India. The Methods Actually Used in Working the Indian Manganese-ore Deposits. ‘We can now consider the methods actually eniployed for the extrac- tion of the Indian manganese-ores. In the first place it must be remarked that owing to the occurrence of large bodies of cre at the surface, the ore of which can be won with little trouble, practically all Indian manganese extraction comes under the head of quarrying. In rare instances, such as at Kodur, Ramandrug, and Bikonhall, small tunnels have been driven into the quarryside or hillside, in order to extract ore, or test the extension of the deposit below the level at which work was actually being carried on. Such tunnels can be put under the head of mining ; but this is all that can be so described. There is of course no doubt that in India the conditions—chiefly the presence of large quantities of high-grade ore at or close to the surface, and the cheapness of the labour—greatly favour quarrying as compared with mining. But, there is also little doubt that considerable portions of the ore-bodies in some parts of India lie at such depths below the surface that they can be worked only by true mining methods. And to me it seems there is little doubt that in years to come, after the more-eagsily-won portions of the deposits lying near the surface have been removed, it will be found necessary to resort to mining And with a view to this some of the manganese companies and syndicates will probably find it desirable to test the extension of their deposits, below the depths at which they are at present working, by means of bore-holes, 568 MANGANESE DEPOSITS OF INDIA: MINING. [Part IIT: and of tunnels into hillsides, in the case of deposits forming compara- tively high hills, It is interesting to note here that although practically all the manga- : _. nese workings in India can be most accurately Indian manganese quarrieS ° - z legally mines. described as ‘quarries’, yet according to the Indian Mines Act, 1901, clause 3 (qd), the term ‘mine ’ applies to all workings made for commencing or opening any mine ; * but it does not include any pit, quarry or other excavation the depth of no part of which, measured from the level of the adjacent ground, exceeds twenty feet and no part of which extends beneath the superjacent ground’! Hence al] manganese workings deeper than 20 feet are legally mines, and as such subject to the operation of the Indian Mines Act, 1901. Hence, except in this chapter, I have not been strict in the use of the term ‘ mine’ as applied to the Indian manganese workings, and have often used it in lieu of the more correct term ‘ quarry ’. From the point of view of the extraction of ore the Indian manganese-ore eee _ deposits may be divided into two main groups, Classification of deposits. 65h with two sub-divisions, as follows :— A. Those occurring on hills, ranging in height usually from 50 to 500 feet ; divided into :-— (a2) Those that form a sort of backbone to the hills, often extending down to and below plain level. (5) Those that form cappings to the hills. B. Those lying on low ground so that their highest points are, or were before being worked, either just a few feet above the level of the low ground, just on a level with it, or even a little below, the presence of the deposit in the last case being indicated as a rule by the presence of detrital ore on the surface ; divided into :— (a2) Those extending to some considerable depth below the surface, either in the form of a sheet-like mass or bed, or in the form of an irregular mass or masses. (b) Those of purely superficial character, that do not as a rule extend to greater depths than 20 or 30 feet. 1 W. H. Pickering and W. Graham, ‘The Indian Mines Act, 1901’, p. 12 (1997), Caleutta. §. K. Lahiri and Co., Calcutta. Cusp. XXVII.] CLASSIFICATION OF DEPOSITS. 50y As examples of the foregoing divisions the following may be mentioned :— A. (a) The Kajlidongri deposit, Jhabua State ; many of those of the Central Provinces, such as Kéandri, Mansar, Bélaghat, Manegaon. A. (6) Nearly all the deposits of the Sandur Hills and Mysore, and most lateritic deposits. B. (a) Many of the deposits of the Central Provinces, such as Kode- géon and Waregdon ; alarge number of those of Vizagapa- tam, such as Kodur and Perapi. B. (6) Several of those of Mysore, such as those near K4rekurchi, in the Tumkur district. There are of course many deposits that do not fit conveniently into this classification. Thus Kumsi in the Shimoga district, Mysore, occurs on the slope of a hill. It can be put into A. (6), however. The chief difference caused by the situation of the deposit is that when working on a hill drainage troubles are avoided, if the work is done ration- ally, whilst the labour of transporting the ore to the stacking ground can be greatly facilitated by the erection of aérial ropeways and inclined planes, gravity being the motive power; see Kandri (Plate 28), Mansar (Plate 33), and Balaghat. In this way large quantities of ore often can be won for many years from the hill deposits before quarrying down to the level of the surrounding plains. On the other hand, in the case of a quarry commenced at the level of the plains, as soon as a depth of 20 to 40 feet is reached, water troubles usually begin, so that extensive pumping is required, as at Kodur (Plate 47) and Garbh4m in the Vizagapatam district, and Beldongri and Kacharwahi in the Central Provinces (Plate 41). Eventually a depth is reached at which it becomes a matter of great difficulty to quarry the ore, and it is then that proper mining operations become necessary if the deposit is not to be abandoned, as was done in the case of the Waregaon deposit, in the Nagpur district. But in the case of such a deposit as Waregdon, which is imagined to have given out at the same time as water troubles prevented further work, there seems to be no desire on the part of the miners to ascertain to what depth the ore continues, and determine whether it would be worth while to try and win the remainder of the deposit by mining it. The chief difference between the working of the deposits of groups A.(a) and A.(b) is that in the latter case the problem is simply one of removing a lil i. 570 MANGANESE DEPOSITS OF INDIA: MrnING. [Part IIT: capping of some 50 feet in thickness, or less, and separating the ore from the rock with which itis so often associated and intimately mixed, this admixture being due to the fact that these cappings are usually the result of the superficial, and often very irregular, replacement of some practically non-manganiferous rock ; whilst in the case of A. (a) provision has to be made for the probability that the ore-body extends into the hill as a sort of backbone, by carrying out a sufficient amount of deadwork to prevent the quarry becoming an ever-narrowing groove. The chief difference between the workings of the deposits of groups B. (a) and B. (6) lies in the fact that the deposits of group B. (b) do not extend to any depth ; so that it is not necessary to make the provision in the way of deadwork that is necessary in the case of the deposits of group B. (a) to prevent them becoming ever-narrowing grooves or pits. Whatever may be the situation of the deposit,a large propor- tion of the work is done by hand. When in very hard, compact masses the ore is first hand-drilled, two men usually working at each drill (see Plate 30), and then blasted. Otherwise it is simply prized out with crow- Seer ae ; bars, advantage being taken of the divisional rie escription oO methods of working Indian planes of the ore-body when such are present. manganese-ore deposits. The huge blocks thus detached are broken with heavy sledge-hammers to a manageable size and then, though with many exceptions, carried down the hill, or up out of the quarry, as the case may be, on the heads of women and children. At a number of quarries light rails have been put down to facilitate the disposal of both manganese-ore and waste. The ore is, if necessary, cleaned by women, children, and old men, with small cobbing-hammers, and finally piled into rectangular stacks ready for measurement. Where a chemist is employed the stacks are usually sampled (Plate 36), and assayed separately, and the ore then carted or trammed to the railway station, where the products of different quarries are often mixed or blended so as to yield a cargo of a certain standard (Plate 41). The foregoing represents the most general practice, to which there are of course, many variations. As already men- tioned the carriage of ore from the summits of hills to the foot has been in several cases facilita- ted by the construction of gravity-inclines (gravity tramways) and aérial ropeways. Gravity-inclines have been constructed at Kandri, Mansar, and Balaghat, all worked by the Central Provinces Prospecting Syndi- cate, and at Ramandrug, worked by the General Sandur Mining Gravity -inclines and aérial ropeways. Cuap. XXVII.1 METHODS OF WORK. 571 Company, Limited. Aérial ropeways have been erected at Kandri, Mansar, and Ramandrug. Of these the Mansar ropeway has been dis- mantled and replaced by agravity-incline. The Ramandrug one has a length of about 2,400 feet with seven supporting trestles, and lowers the ore about 750 feet. The details as to these ropeways and inclines wil! be found under the headings of the respective deposits. Occasionally ore-shoots have been constructed to facilitate the lowering of ore from one level to another, as at Manegaon, worked by the Central India Mining Company, Limited. The rails used on the mines are usually of 2-foot gauge, but are occasionally of 2’ 6” gauge, as on the mines ee of the Central Provinces Prospecting Syndicate. Mining tramways and ‘ : railways. In several cases light steam tramways or light railways have been constructed to connect up various mines to the railway systems of the country. An account of these is given on page 477. On the 2-foot gauge lines laid down by the mining companies, the trol- lies or trucks usually used hold from one to two tons, according to the size of truck. The New Mysore Manganese Company, however, is using some trucks that hold up to three tons of ore. On the 2’ 6” and metre- gauge lines constructed by the railway companies, wagons holding 6 to 16 tons are used. Samples for analysis are not always taken from ore stacked at the mine as mentioned on page 570; at some mines the ore is never stacked. Thus, at Balaghat, the ore receives what cleaning it needs near the working face and is then charged into mine trollies and conveyed by a series of tramways and inclines to the railway wagons. The ore is sampled by taking some ore out of each mine trolly as it passes the manager’s bungalow. At Kumsi the ore is railed part of the way and carted the remainder. The chemist takes his samples from the carts on arrival at Shimogal. Sampling. I do not propose to give here descriptions of how particular deposits are worked. For this I will refer the reader to the fourth part of this \emoir, There he will find, at the end of the description of each deposit, an account of the way in which it was being worked at the time of my visit. The description given on page 570 applies to most of the deposits. But in a few cases the work has been carried out on more elaborate lines ; for this attention may be directed to the descriptions of the way in which 1 For some remarks on sampling Indian manganese-ores see Trans. Min. Geol. Inst. Ind., II, pp. 95—98, TI L 2 572 MANGANESE DEPOSITS OF INDIA: MINING, [Part III: the Kandri, Mansar, and Baldghat deposits, are being worked, these being the best examples of deposits well worked. It will have been gleaned, however, from the earlier portions of this chapter, that many of the Indian manganese-ore Deposits often badly deposits have been very badly worked. In my worked. paper ‘ Manganese in India ’, p. 107, I wrote :— «ore has often been recklessly extracted to meet present demands and contracts without any regard either to geological considerations or the future working of the deposit. This has frequently resulted in the subsequent discovery, either that the waste or mati has been dumped on to the hidden extension of the ore-body, or that so much dead-work will be necessary before the miner can work ata slightly increased depth, that it becomes a matter of doubt if the deposit can any longer be profitably exploited ; such want of foresight and reckless working leads, of course, to a grievous waste of the country’s mineral resources.’ Since this was written | have been able to revisit some of the deposits in the Central Provinces. I was pleased to find a general improvement in the methods of work, although there were still some deposits left to which the foregoing was applicable. I have also since visited some of the Sandur deposits, and some of those of Mysore. The Sandur deposits were being worked with some care and forethought. So also were some of those of Mysore ; but not the majority. The majority were being worked in avery careless fashion; but, considering the fact that these deposits do not extend to any depth, this is not a matter of much consequence. In working loose detrital deposits, however, it must be very difficult to tell which ground has been worked over and which not, if the waste is dumped immediatety by the side of an excavation and on top of ground not worked over, as noticed on page 565. Ihave heard it remarked that working some of the Mysore deposits is like digging for potatoes. The simile was meant to apply to the irregular distribution of the ore in the lateritoid masses. But it is more aptly applied to the deposits of detrital ore, where fragments, pebbles, and boulders of ore he scattered through a clayey soil ; except that in some cases the workings are much less regular than digging for potatoes would be if the digger did not wish to leave a considerable proportion of his potatoes in the ground. Not only is there in India a strong tendency to work the manganese- ore deposits in a very wasteful way, especially at the beginning of work by a new operator, but there isalsoa tendency to waste a considerable proportion of the ore won. To begin with, all ore at all small in size, say below one inch jn diameter, is in most cases thrown away irrespective of quality, Waste of smalls and dust. Cuap. XXVII.] WasTE OF SMALLS AND DUST. 573 probably because some mechanical treatment might be necessary to Separate these small pieces from small pieces of foreign matter. It is to be noted that the worst offenders in this waste of smalls are those opera- tors who can obtain large quantities of ore in large pieces. Operators with properties that turn out inferior grades of ore only, do often stack these smalls and seem to be able to find a market for them. Further, at many even of the best deposits, a certain proportion of the ore breaks down into powder during excavation. This applies particularly to those deposits in the Central Provinces in which there is any ore consisting entirely or almost entirely of granular braunite, without any psilomelane as cementing material. Kandri is a good example of a deposit in which a lot of the ore breaks down into powder on quarrying. All this is wasted. The same applies to deposits in which there is a con- siderable proportion of pyrolusite, such as some of those of Vizagapatam, and many of those of Mysore. In some cases pyrolusite has been bagged and sold, as at Kodur in Vizagapatam, and Hoshalli in Mysore. But in the majority of cases this pyrolusitic ore is stacked in such lumps ar can be obtained, all that breaks into powder during quarrying being - lost. Such ore if exported in the unbagged condition must then inevi- tably loose greatly in weight owing to powdering at every transhipment or dumping. My opinion is that such soft ore should be bagged at the mine, and that when a large amount of ore breaks down into powder, some attempt should be made to recover this by some means of washing the dust and concentrating it ; this applies especially to such a deposit as Kandri, whence there‘is a large outturn of lump ore bringing in a handsome profit to the operators, so that there can be no lack of the comparatively small capital required to provide the plant that would be needed for the treatment of smalls and dust. It is very pleasing to the miner to export the very best ore and make a sovereign a ton profit on it with a comparatively small amount,of trouble, and to neglect all ore that will not bring in profits at the same rate; but it is not gratifying to India, to see a portion of her mineral capital wasted. Similarly, of the ore that is obtained in lump size, only that of the very best quality is considered worth noticing Waste of low-grade and in some quarters in the Central Provinces, It ase, ton: tae is probably sometimes the case that a firm wishes to get a reputation for supplying ore only of a certain quality, although it could also work lower grade ore at a profit if it liked. To do this such firms throw away all ore of lower grade than their standard, 574 MANGANESE DEPOSITS OF INDIA: MINING. [Parr III: except what they can blend in with the highest grade ores without the product falling below the standard. But much of such ore as is rejected could probably, with a little trouble in cleaning it, be sold at a profit, at least at times of high prices. It seems moreover to be overlooked in India that much of the ore that is rejected because it is too high in silica, although it is not very much below marketable standards as regards manganese contents, could be worked up into a merchantable product by crushing and concentrating. Hach particular case would Pasaibility "GF washing need investigation to see if such a process concentrating, and briquet- could be commercially successful, considering cipro the distance of the markets. But I think that in many cases the treatment of this ore would pay, at least at times of high prices. And in the event of the ore being smelted in this country for the manufacture of ferro-manganese there could be little doubt of the financial possibility of such a project. It is probable, however, that, if the Indian manganese operators have considered any such project, they have rejected it because they can supply all demands from the easily- won lump-ore of high grade, and not because they have seriously determined that it would be financially impossible. In case then the Indian manganese operators are content to make use only of the high- grade lump-ores, I think they should recognize that they are probably throwing away large quantities of material that has a possible value in the present and a more probable value in the future, and that they should make some attempt to stack the lower grade and siliceous ores separately from the waste thrown on the dumps. Methods of Mining, Washing, Briquetting, etc., used'!Abroad. The reasons why I think that washing, and concentrating if necessary the fines, and crushing and concentrating the low-grade ores at present thrown away, and in either case either bagging or briquetting the product, could be made a commercial success, is that it has been done in several cases before in other parts of the world. Thus Mr. H. Kilburn Scott in some notes appended to a letter sent to me in February 1906 refers to the briquetting of manganese-ores in Brazil as follows :— Briquetting in Brazil. ‘The Usina Wigg, the principal mine operator in the Ouro Preto Branch Line deposits, commenced last year the erection of a plant for briquetting the finely divided ore after reducing its moisture contents. Cuap. XXVITI. ] METHODS USED ABROAD. 575 ‘The installation has been carefully designed, and will have a capacity of 100 tons of briquettes per day. The process has been evolved by Messrs.’ Zeitz & Co. of Saxony who are supplying the greater part of the machinery. The binding material will be furnished by a proportion of the moisture left in the ore after re- ducing to the size of 14 millimetres. The presses will work with a pressure of 10 tons per square inch and the briquettes will weigh 800 grammes each. * Experimental briquettes have been found to resist shock and high tempera- ture without disintegrating, so much is expected from the process.’ The Brazilian ores are very high in moisture (up to 20%) ; in bri- quetting soft Indian ores it might be necessary to add moisture. Further in an article in the Engineering and Mining Journal, 9th March 1907, p. 478, Mr. E. K. Judd gives an interesting account Hydieulickingandwash. ©! the way in which the manganese-ore deposit ing at Crimora in Vir- at Crimorain Virginia is worked by the Crimora Je Manganese Company, by hydraulicking and washing. In order to show with what elaborateness a manganese-ore deposit may be worked I quote extensively from this article :— * The Potsdam quartzite, forming the base of the district, has been eroded by some peculiar agency so as to form a bowl, perfectly inclosed on all sides, except, where, at the north, a stream has eroded a narrow gorge. This drains only a small part of the bowl, and the remainder has no natural drainage whatever. The bottom of this bowl has been filled to a depth of 212 ft., at the centre, with a stiff red clay, covered with a layer of gravel drift with an average depth of 15 ft. In this clay, manganese oxides are found in rounded concretions, and irregular pockets, seams and stringers, whose position follows absolutely no apparent rule. They are found at all depths, and in all shapes and sizes, from that of a pea to masses of several tons weight ‘The manganese-bearing portion of the bowl has been determined, by drill borings, to cover an area of a little over 100 acres. Method of Mining. ‘In the early days, when the ores first attracted the attention of the Carnegie steel interests, the clay was thoroughly honeycombed with shafts and drifts which required timbering of the most substantial nature. The lowest workings of that epoch reached a depth of about 100 ft, below the original surface, when the copious influx of water naturally gravitating to this spot and finding no outlet, forced aban- donment of the project. Although the old operators removed the choicest ore- bodies, the inefficiency of their methods is shown by the great quantity of valuable ore that is now recovered, by open working, from the close neighbourhood of the old openings, and even in among the very timbers of the disused drifts. “ The present system of mining may have been suggested by that so successfully practised among the largest gold gravel operators of the Sierras, but it is probably unique among manganese miners. The first step was to drivea drainage tunnel 5,800 ft. long through the quartziterim, tapping the bottom of the basin at its lowest point, and discharging into one of the small streams that flow into the south fork of the Shenandoah. A shaft 202 ft. deep then connected its inner end with 576 MANGANESE DEPOSITS OF INDIA: MINING. [Parr IIT: the surface. RIn{the neighbouring mountains, an extensive system of reservoirs and flumes was then constructed, ending in a small masonry tank above the mine, from which a steel pipe, crossing on a trestle the deep gulch above referred to, jeads the water to a nozzle in the working place. The tank is now 224 ft. higher than the nozzle, and the discharge is 640 gal. per minute. “ The wash from the clay banks thus attacked is allowed to settle in the bed of the working place, so that only the clay is carried off in the overflow down the drainage shaft. The sand and gravel, together with the big fragments of ore, are then collected in cars travelling on movable tracks, and carried to the washing plant, close to the edge of the pit. The area now under work covers 5} acres, and a depth of 56 feet below its present level will have to be gained before the untouched ore will become available. The entire output now comes from ground that was overlooked by the earlier workers. An ordinary section of clay bank, in which no especially heavy lumps are encountered, will carry around 10 per cent., by weight, of.manganese oxides. Wad, which is rather abundant in some spots, can not be saved in this way, and is lost. In any case it would require calcining to bring it up to shipping grade. * A steam shovel is used for removing the graveloverburden. Trains of dumping cars are brought around to it, on track laid clos> to the edge of the pit, loaded, and drawn off to a waste dump at some distance from the mine, at a total cost of about 6c. per cu. yd. Waste from the washery is disposed of in the same way - Washery Operations. * Th washery has a double-tracked incline extending from its top fioor to the bottom of the pit, and carrying a pair of self-dumping skips. ‘The loaded cars from the pit, whose contents still retain a lot of adherent clay, dump into a sump which is kept half full of water, so as to cause the material to flow easily. The mixture is then drawn off through gates into the skips and hoisted to the top of the washery. Here it passes into an inclined double logwasher fed abundantly with water, where most of the clay is washed off and discharged. The lumps then go through a crusher and into another, but horizontal logwasher, where the last clay is removed. ‘The discharge from this washer goes into a trommel with &-inch holes; the oversize passes to picking belts where waste is discarded and the ore becomes ready for market. The undersize goes to another trommel, which makes four sizes, and each size falls into a separate jig. The McClannahan jig has proved admirably suited for this work and makes a clean separation into heads and tails, with no middling product. The tails, carrying 3 or 4 per cent. of manganese, are sold to foundries and basic steel makers. The waste from the picking belt some- times carries as much as 20 per cent. manganese. A great deal of this waste is in the form of quartzite conglomerate, manganese oxide being the cementing agent, and, if crushed again, might yield some good ore; the management, however, is s toring this material until it can find a market, it being worth more than jig tailings. ‘No attempt is made to reduce the size of the ore, the management preferring to sell its product in lump form to the steel industry... . . It is probable that the small additional outlay for grinding equipment would prove a good investment, since the other consuming industries, the glass, the paint, and the storage battery manu- facturers, are accustomed to pay about-double the price allowed by the steel makers. ‘The lump ore shipped from the mine averages around 48 per cent. metallic manganese, and occasional lumps reach neariy to 60 per cent. Phosphorus rarely Cuar. XXVII.] METHODS USED ABROAD. 517 exceeds 0-10 per cent., but silica is rather high, ranging from 2 or 3 up to 15 per cent. The jig concentrates range in silica 2 or 3 per cent. higher than the lump ore produced at the same time.’ As a further example of the trouble that is thought worth while Seeded mitral in other parts of the world in working manga- ing, ete., employed in nese-ore deposits, so as to make use of all pos- ene. sible ore, I give the following abstract from a paper by Mr. E. G. Williams, entitled ‘The Manganese Industry of the Department of Panama, Republic of Columbia’, Trans. Amer. Inst. Min. Eng., X XXIII, pp. 214, 215 (1902). “The discovery outcrop is about 100 ft. below the summit of the hill, An open cut was begun about 20 ft. below the outcrop and carried in until the walls were 100 ft. high. The mountain, rising faster than the ore-body, gave a con- stantly increasing over-burden to remove ; and this, with the difficulty of holding the side-walls, led to the abandonment of open-cut work and the beginning of under- ground mining in 1898. A tunnel was driven into the ore-body from the open-cut level, and from the same level a shaft was sunk 110 ft. and two levels were opened. The mine is drained by a tunnel on the bottom level connecting with the shaft. “The ore is usually stoped for the entire width of the deposit, both heavy tim. bering and supplementary filling being required. At some points it is necessary to leave pillars of ore in place, to be extracted when the stope is about to be finally abandoned. The ground is difficult to hold, because of the decomposed rocks surrounding the ore and the large masses of clay associated with it. Occasionally a pocket of clay is opened which is under heavy pressure from the surrounding rock or ore. As soon as an outlet is furnished, the clay begins to flow into the stope in a plastic mass; and great difficulty is often experienced in checking this fow. The most satisfactory method of working—indeed, the only one by which the soft clay walls can be held—is to keep the stopes filled to within about 7 ft. of the roof. The ore-shoots and man-ways are built up from the level below, as the filling is carried up. The material for filling, apart from what is furnished from waste in the mine, is obtained outside, on the open-cut level. * Square-set timbering has been used in large stopes, but it has been found better and cheaper, where the filling system was employed, to support the roof with cribs of round logs, which accommodate themselves, without damage, to the shrinkage of the newly-filled material and the pressure from the ore. * The ore from the lower levels is hoisted to the open-cut level by a gasoline hoist, which was installed on account of the difficulty of obtaining a supply of water through the dry season. “The ore is hand-picked on the open-cut level, the large pieces going direct to the tramway which connects the mine with the railroad, while the small pieces and finely-powdered ore are transported separately, taken to the log-washer, and screened after washing. ‘The size above 0°5-in. mesh is hand-picked and shipped; the finer portion being reserved until a suitable concentrating-plant shall have been erected. This care in sorting the ore is rendered necessary by the presence of particles of jasper in the ore, which, if not removed, subject the ore to a penalty for silica. ‘The ore is stored on the upper level of a 50-ton bin at the loading terminal of a Bleichert tramway. This tramway, about one-third of a mile in length, has 578 MANGANESE DEPOSITS OF INDIA: MINING. [Part III: its upper terminal 420 ft. above the railroad to which it conveys the ore. At the railroad there is a 300-ton ore-bin, from which the railroad cars are loaded. The tramway is operated by gravity, the descending loaded buckets developing 6-H.P. All mine-supplies, timber, etc., are brought up to the mine on the tramway, which has a capacity of 25 tons per hour. ‘Hand-drilling was used until the present year, when, on account of the difficulty of obtaining labourers during the revolution in the country, an air-compressor was installed, driven by a 35-H.P. gasoline-engine, and power-drills are now used.’ From this account it will be seen that not only has it been found profitable to work the deposit (the Soledad deposit) by the methods of underground mining, but it has also been thought worth while to wash and screen the smalls, whilst it was intended to set up a concentrating plant for ore passing a 3-inch sieve. It is also interesting to note that power drills have been introduced in place of hand-drilling. The ores shipped from this deposit are of about the same grade as those of Kandri, The methods described have been no doubt largely adopted on account of the scarcity of labour. The same desire to save labour appears in the arrangements for the transport of the ore which are described as follows (loc. cit., p. 219) :-— ‘From the bins at the railroad the ore is loaded by gravity into small side-dump- ing cars, of about 3 tons’ capacity, and hauled to the shipping-port. Here it is dumped from a trestle upon the stock-pile. There is storage here, without re- handling, for about 3000 tons. The ore is shipped in steamers which are loaded alongside the Company’s wharf. It is loaded into tubs, holding about 1800 Ibs. each, which rest on small trucks running on a track of 0°5 meter gauge. There are two endless tracks, one on each side of the ore-pile, extending on to the wharf. The ore-trucks make a continuous circuit, the loaded tubs being hoisted and their contents dumped into the steamer’s hold, and replaced empty up on the truck which then returns to the ore-pile to reload. Each track serves a separate hatch on the steamer ; and the ore is loaded at the rate of 400 tons or more daily.’ This railroad is of 3 feet gauge, 9 miles in length, and connects up the Soledad and Concepcion mines of the Caribbean Manganese Company, by whom it was built, to the port of Nombre de Dios. Amongst other deposits at which true mining methods have been Mining of manganese-ore @dopted, or at which the ore is subjected to deposits in other partsof some sort of concentration, or other mechanical the sore: treatment, the following may be mentioned :— 1. The Miguel Burnier mines, Ouro Preto area, Minas Geraes State, Brazil!. Steeply-bedded deposit of average width of 2 metres. Levels driven into hill-side at vertical intervals of 30 metres, and ore stoped out. Briquetting of ores. 1H. K. Scott, Jour. Iron Steel Inst., No. 1 of 1900, pp. 190-195. Cuar. XXVII.] METHODS USED ABROAD. 579 2. Morro da Mina deposit, Queluz area, Brazil!. A vertically dipping deposit of great thickness, the ore being interbanded with clay. Tunnels driven into the hillside at depths up to 147 feet below original outcrop. 3. Ponupo deposits, Santiago de Cuba area, Cuba 2. Irregular pockets in clay and associated with jasper and porphyry at the surface. Some of the ores are washed and concen- trated. 4. Las Cabesses deposits, Ariége, France 3. An irregular carbonate deposit, altered to oxide at the surface, associated with Upper Devonian limestones. In 1894 a depth of 70 metres had been reached, and the deposit was worked by a series of 8 levels. The ore was treated by means of syringing and hand-picking, grizzlies being used to separate the smalls, and trommels to classify them. The ores are finally roasted. 5. Romaneche, Sadne et Loire, France 4. Veins, up to 8 metre? wide, and masses, of psilomelane and pyrolusite, associated with fault-junction between granite and Keuper, Liassic, and Tertiary, sediments. Worked by shafts. levels, stopes, etc., and gradually passes into iron-ore (hematite) at depths of 260—330 feet. 6. Island of San Pietro, Sardinia >, A seam of manganese-oxide ore, averaging 10 inches in thickness, associated with ochres, and interbedded with trachytic rocks. Average manganese percentage only 30%. Worked by galleries and cross-cuts with timbering. ~] . Rhiw Mines, Caernarvonshire, North Wales ®& The workings are in veins of ore from 4 to 30 feet thick. Ore averages 30 to 369% manganese, iron 7 to 10%, silica 18%, phos- phorus } to 34%. Worked by adits and shaft; a depth of 110 feet reached. i LS |. | Se ce 1 M. A. Lisboa, Reprint from Brazilian Engineering and Mining Review, UI, Nos. 6 & 7. eceived 1907. * a ae Trans. Amer. Inst. Min. Eng., XXXV, pp. 309-312, (1904). 3 ©. A. Moreing, Trans. Inst. Min. Met., I, pp. 250-264, (1894). 4 Fuchs’ & Launay, ‘ Gites Minéraux’, IT, pp. 13-16, (1893). ; 5 E. Halse, Trans. North Eng. Inst. Min. Mech. Eng., XXXIV, pp. 145-158, (1885). 6 Mining Journal, June 22nd, 1907, p. 828. 580 MANGANESE DEPOSITS OF INDIA: MINING. [Part IIL: Grant of Mineral Concessions in India. Originally it was my intention to give in this Part cf the Memoir an account of the regulations governing the grant of prospecting licenses and mining leases (1) in British India, (2) in Mysore, and (3) in Portuguese India. But unfortunately I have not had the time for this. Still I can indicate here the sources of information available. The regulations for British India are contained in Resolution No, 18—17-2, dated Simla, the 20th May 1899, of the Department of Revenue and Agriculture. Mr. C. KE. Lew, Director of Industrial Surveys, Central Provinces, has prepared a handbook explanatory of these regulations with regard to their bearing on the Central Provinces. The rules are, however, at present being revised. Mines in Pritish India are worked under the Mines Act, 1901, for which see a small book of this title by Messrs. W. H. Pickermg and W, Graham, pub- lished in Calcutta, in 1907, by Messrs. S. K. Lahiri & Co, The rules in force in Mysore are contained in ‘Notification by the Government of His Highness the Maharaja of Mysore, Geological Department, No. 555-8., dated 2nd March 1904’. These were modified in subsequent Notifications Nos. 2490, 2521, and 2759, dated Ist, 4th, and 13th June, 1906, respectively ; these have, I believe, been subsequently cancelled, leaving the Notification of 1904 still in force. The regulations appli- cable to the Portuguese territory of Goa are contained in ‘ Boletim Official do Governo General da Estada da India’, No. 84, dated October 23rd, 1906. A translation of this has been prepared by Mr, R. A. Becher, His Britannic Majesty’s Consul at Goa, and is for sale at the British Consulate at Mormugao. CHAPTER XXVIII. ECONOMICS & MINING—conétinued. The Uses of Manganese. Uses in metallurgy—List of uses—History of the application of manganese in the iron and steel industry—Spiegeleisen and ferro-manganese—Manufacture of spiegeleisen and ferro-manganese—Manufacture of ferro-manganese in India—Use of spiegeleisen and ferro-manganese—Quantity of manganese required in the manufac- ture of steel—Phosphorus and silicon in spiegeleisen and ferro-manganese—Use of the Indian phosphoric ores—Use of manganese-ore for de-sulphurizing—Manganese in foundry practice—Manganese-steel—Effects of manganese on iron and stee]— Other manganese alloys—Silicon-spiegel—Manganese-bronze—Metallic manganese. Smelting of manganese-ores by the natives of India—Kheri. Use of manganese ovide as an oxidizer—For the decolourization of glass—For bleaching powder, bullion smelting, and potassium permanganate. Use of manganese as a colowring material—For glasses and enamels—For pottery. Ornamental applications. It has already been shown how widespread is the element manganese in Nature (see pages 18-20). The following list! will give some idea of the numerous uses to which manganese and its compounds have been applied by man :-— TABLE 88, List of uses of manganese. ( Ferro-manganese. ) | Spiegel-eisen. Alloys of manganese and iron. | Manganese-steel. 5 | Silicon-spiegel. Alloy of manganese, iron, and silicon. 1.—Alloys 4 M " ¢ Alloy of manganese and copper with eee eee or without iron. | re Na ps ( ries cee a aluminium, zinc, | Alloys of manganese with aluminium, zinc, tin, lead, mag- nesium, titanium, gold, etc. (Manufacture of chlorine, bromine, and bleaching powder. | Decolourizer of glass. | Dryer in varnishes and paints. I].—Oxidizers + Leclanché’s cell. Preparation of oxygen on a small scale. Manufacture of disinfectants (manganates and permanga- iL nates). 1 Based on that of Penrose, An. Rep. of the Geol. Sury. of Arkansas for 1890, Vol. I. ‘ Manganese: its Uses, Ores and Deposits’, p. 7. 582 MANGANESE DEPOSITS OF INDIA: Economics. [Part IIT: I1I.—Colouring ate Colouring glass, pottery, tiles and bricks ne Green. Penn { Violet, IV.—Various lesser chemical, manufacturing and medical purposes. V.— Occasionally as a gem when in the form of rhodonite or spessartite, ViI.—Oceasionally as a flux in smelting silver-ores. {Coloring ls and dyeing. I do not propose to discuss here each of the applications of manganese mentioned in the preceding table. That will be found already accom- plished, as far as they had been discovered up to 1890, in the most interesting fashion in the work of Penrose just quoted. But I shall notice briefly the most important uses, namely;in the metallurgy of iron and steel, and a few of the others as applied to India. Uses in Metallurgy. In all probability at least 909% of the world’s output of manganese- History. of the lapphen eee is consumed in the manufacture of iron and tion of manganese in the steel. It will therefore be interesting to trace tron end steel Renee briefly the history of the use of manganese in the iron and steel industry. Between the years 1799 and 1837 various patents were taken for the use of manganese in metallurgy. In 1830 David Mushet even succeeded in making a low-grade ferro-manganese containing 309% of manganese. Josiah Marshall Heath, however, in . 1839, was the first to conduct experiments on a large scale and bring manganese into general use in the iron and steel industry. Heath was a Madras civilian who abandoned the Indian Civil Service to take up the development of the iron industry of Southern India. He attempted to make use of the low-grade iron-ores used by the natives of Porto Novo in the North Arcot district, in the manufacture of wooiz, a variety of steel produced by cementation in crucibles. According to Penrose! on whom this account is based, and for whose book see for the references to the literature of the subject :— ‘He not only succeeded in this, but also completely revolutionized the steel industry of England. His original object was to improve both malleable iron and cast steel. In the first case he mixed with the cast or plate-iron, while fused in the puddling furnace, from 1 to 5 per cent of pure oxide of manganese, the ses- quioxide being preferred. In the second case he mixed in the crucible, with the materials to be converted to steel, from 1 to 3 per cent of what he called carburet of manganese. The latter consisted of a manganese pig corresponding to white iron pig, and was composed of metallic manganese with a small proportion of carbor, 1 Loc, cil., p. 13. Cnap. XXVIII.| uses OF MANGANESE IN METALLURGY. 583 It was made by smelting an intimate mixture of oxide of manganese and coal-tar. - By the addition of this material, it was found that the low grade steel made from the Wootz ore could be converted into an excellent product, easily malleable and weldable.’ He later improved his process by moulding the manganese oxide and tar into bricks, drying them by heating in a closed vessel, and using them in their raw state. ‘In this form he soon found an extensive demand for this manganese compound among the steel manufacturers, who, after the first trial, realized the great advantage derived from it. Heretofore the best quality of steel in England had been made of high grade and expensive bar-iron from Sweden and Russia, but by the employ- ment of Heath’s process it was possible to make an equally good product from a comparatively low grade iron of English manufacture.’ Heath lost the benefit of his researches through neglecting to patent the use of his mixture in the raw state. D, Mushet calculated that the immediate result of Heath’s invention was a reduction of £30 to £40 in the price of good steel, with an aggregate saving up to 1855 of £2,000,000. The Bessemer process for making steel was made public in 1856 and perfected by 1858, the difficulties experienced in the early working of the process, owing to the burning off of all the carbon in the converter, being obviated by the introduction by Robert Mushet in 1856 of a ‘ triple compound ’ of iron, manganese, and carbon, an early form of the alloy later called spiegeleisen. This alloy was used in the Bessemer process for adding to the steel the requisite amount of carbon, the manga- nese performing various offices, then not properly understood. The need for an alloy containing a higher percentage of manganese than that in the aap then made (5 to 10% of manganese and some- times 6 to 79% of carbon) soon arose, and as eke ecules of some experi- ments cred out by W. Henderson of Glasgow, at the instigation of Bessemer, a ferro-manganese conta‘ning 25 to 30° of manganese was produced in 1865. A little previous to this, however, Dr. Prieger of Bonn seems to have already succeeded in making a high-grade ferro-manganese,. The process was taken up by the Terre Noire Company of France, and from about this date a greatly increased demand for manganese-ore sprang up (see account of fluctuations of price of manganese-ores given on page 414, Spiegelersen is an alloy of iron and manganese containing usually 5 to 27% of manganese and 4 to 5% of carbon. It atone mirror-like reflecting cies on frac- tures, and hence the name, which is the German Spiegeleisen and _ ferro- manganese. for mirror-iron, 584 MANGANESE DEPOSITS OF INDIA: Economics. [Part III: Ferro-manganese contains 27 to 86% (or sometimes even 90) of manga- nese and 6 to 7% of carbon. Standard ferro-manganese contains 80% manganese. [ According to O. Simmersbach!, on passing above 27% of manganese, the Fe—Mn. alloys loose their magnetic properties and assume different crystalline characters. ] According to Penrose? :— ‘ Spiegeleisen was formerly made by using a manganiferous iron ore in a blast- : " : furnace, or by inserting small quantities of manganese Saath tat ce Re in the iron ore charge. When the amount of man- ganese became large, however, great difficulties were experienced on account of the high temperatures required to smelt the metal and the loss due to the combination of the manganese with the slag. The more manga- nese contained in the charge the higher the temperature that is required, and a white heat is needed to reduce oxide of manganese alone. Consequently, in the early manufacture of ferro-manganese, the metal was reduced either in graphite crucibles as in Prieger’s method in Germany, or in a Siemen’s furnace as in the Henderson method in England, which was later improved by the Terre Noire Company of France. These processes were expensive, the loss was considerable, and the product limited. More modern appliances, however, and greater experience in the use of manganese-ores have considerably facilitated the reduction of the metal, and now ferro-manganese is readily made in any properly arranged blast-furnace, with a high temperature and a strong hot blast. Coke is the best fuel, as it admits of a sharper blast and gives a stronger heat, but charcoal can be used, and Wm. P. Blake describes the manufacture of ferro-manganese with that fuel from a highly siliceous ore at Reschitza, in Hungary.3 The other desirable features in the process besides those mentioned are: a highly basic slag, secured by large charges of lime ; an abundance of fuel ; and sufficient time. The basic character of the slag causes the saving of a considerable part of the manganese, which with a less basic, or an acid slag, would combine with the latter and be lost. If the slag is too basic, how- ever, other difficulties are met ; and even with all precautions, a loss of 4 to some- times over 15 per cent of manganese, the quantity varying according to the amount of the metal in the product to be obtained, is often sustained in smelting the ores’. According to O. Simmersbach, in the article already cited, while 100% (of the metal obtained) of coke is required for the reduction of iron, 250% is required for the reduction of manganese. The charge must be calculated so that the oxygen of the earthy bases, lime, magnesia, and alumina, is at least as great as the oxygen of the silica. A certain proportion of barytes or flour-spar is also necessary, according to some authorities. A practical rule for fluxing given by Phillips and Bauerman4 is to give twice as much lime (in the form of limestone) and $ as much 1 * Uber die Herstellung von Ferromangan’, Berg- und Hiittenmdnnische Rundschau, J, pp. 305-308, (1905) ; abstract in Trans. Min. & Geol. Inst. Ind., I, pp. 133-135, (1906). 2 Loe. cit., p. 11. 3 Trans. Amer. Inst. Min. Eng., 1V, p. 217. (1875-1876), 4 * Elements of Metallurgy,’ (1891), p. 286, Cuap. XXVIII.] ManuractuRE OF FERRO-MANGANESE. 585 barytes as there is silica present in the ore and fuel. An actual example of the charge used at Terre Noire is the following :— Huelva ores, pyrolusite, 9°6 cwts., with Fe= 2-91%. Mn= 52-50% Almeria do. do. 4:0 Fe= 15%, Mn= 509 "2 Tafna do. hematite, 0-4 Fe= 55%, Total :—14 ewts. ore, containing average of 4% Fe, and 50°28°% Mn. For this are required :— oO Limestone .. a a me ee 4:4 ewts. Barytes ae : - op a 1:2 ewts. Or more conveniently we can say that 1 ton of manganese-ore, aver- aging 50% Mn and 4% Fe, requires 6-3 cwts. limestone, and 1-7 ewts. barytes. The product was ferro-manganese containing— Manganese. . =e “3 3 a5 83-90 Jron ce se ae ae Ae 8°83 Carbon & silicon Fs an Es ae 7:26 99°99 and the loss of manganese was 25%. Judging from the amount of limestone used the average silica percent- age of the ores used must have been about 8%, assuming none to have been derived from the fuel. Consumption of coke was 54 ewts, per ton of ferro made. According to T. Turner !, in smelting spiegeleisen, the charges are calculated for a reduction of 75% of the manganese into the alloy, and with ferro-manganese for a reduction of 80% of the manganese. Accord- ing to Simmersbach good ferro-manganese slags contain 7 to 10% of manganese, according to the composition of the ferro-manganese, whilst up to 18 to 20% is not uncommonly found in the slag when easily fusible ores are smelted. Besides the loss of manganese that takes place by passage into the slag, there is also a considerable loss through volatiliza- tion in the blast- furnace ; this may range up to 17% and over of the ori- ginal manganese contents. When apdhae it is necessary to shut off the blast, as otherwise the composition of the metal might be seriously altered both by volatilization and oxidation. Owing to the corrosive action of the manganiferous fumes from the blast-furnace on stonework, it is advisable to pass the furnace gases through a washer or dust-catcher before letting them into the fire-brick stoves. If the ore is highly oxidized, eee a High percentage of nO2, the gases derived from the furnace aie Metallurgy of Tron ? 51) 150, (1895). it M 586 MANGANESE DEPOSITS OF INDIA: EcoNoMIcS. [Part III: have a low heating power owing to the surplus oxygen burning CO to CO9. In this case it may be necessary either to add bituminous coal to the charge to furnish gas for the boilers and stoves, or to calcine the ore beforehand to reduce the MnO, to MngQq4. Ferro-manganese has of recent years also been manufactured in the electric furnace. One of the drawbacks of ferro-manganese for some purposes is the large amount of carbon it contains. A recent paper by Messrs. E. G. L. Roberts and E. A. Wraight!, entitled ‘ The Preparation of Carbon-free Ferro-manganese ’, describes experiments carried out to determine the commercial possibility of refining ordinary ferro-manganese ; the authors consider that the most hopeful method consists in treating the molten alloy with manganese oxide. The paper is valuable for the review it gives of the attempts to make metallic manganese and to manu- facture and refine ferro-manganese. I have given the foregoing brief account of the manufacture of ferro- manganese, because the question of the manufacture of this alloy in India has already arisen, and because it is very difficult to get any definite information on the subject. The details of the manufacture seem to be more or less secret. From the figures given above, however, we can form a rough idea as to the possibility of manu- facturing ferro in India, Let us take the aver- age ore of the Central Provinces to contain :— Manufacture of ferro- manganese in India. Manganese... ac ste “te ee toe Tron ae Si a6 ne oe 7 Silica a ae Fi So .- 63 Phosphorus... did 0-10 Assuming that the loss of manganese in smelting this, without admixture with any other ores, would be 20%, then the composition of the ferro obtained would be :— Manganese... is a: ie oO Tron a Be e ae enlots Carbon and silicon a . a 7253 assuming the total of carbon and silicon to be that given in the last line. By picking out the less ferruginous ores the ferro-manganese could easily be raised to the 80% grade if this were desired. Assuming that for every ton of ferro-manganese 24 tons of Giridih coke would be required, then as this contains about 14 % of ash, which we can assume as equivalent to 6% of silica?, the total amount of limestone required for fluxing the 1 Jour. Iron Steel Inst., No. II for 1906, pp. 229.2886. 2 No analyses of the ash of Indian coals seem to be available. Cuap. XXVIII.] MANUFACTURE OF FERRO-MANGANESE. 587 silica in both the ore and fuel would be 0:98 ton for each ton of ferro- manganese made, Hence the total charge would be in the following proportions for every ton of 79% ferro made :— Manganese-ore Ap ae ee 1°9 tons Coke es 56 =F kee 275 Limestone XE é : : 1-0 Now the average price for first grade ore from 1901 to the beginning of 1908 has been 11-13 pence per unit of manganese. Let us take 1l pence. The c.2.f. value of 52% ore at United Kingdom ports would therefore be Rs. 35-12 per ton on the average; allowing Rs. 13-4 (see table 50) as the cost cf sending this cre from Bombay to England, the f. o. b. or export value at Bombay would be Rs. 22-8 per ton. Let us assume, for the sake of a concrete example, that it is proposed to make the ferro-manganese at Sini, Bengal-Nagpur Railway. As this place happens to be about the same distance (521 miles) from Kémthi as Bombay is (529 miles), Kamthi ore delivered at Sini would have to be paid for at the export value at Bombay, namely Rs. 22-8 per ton. The coke would probably not cost more than Rs. 16 per ton! in wagons at Sini. The cost of the limestone I do not know ; but it would probably not be more than Rs. 5 delivered at Sini, especially if the Bisra limestone should prove suitable. Hence the cost of the materials necessary for the production of one ton of ferro-manganese is as follows :— Rs. a 1-9 tons of manganese-ore . - : : : 42 12 2°5 tons of coke , s : es ‘ : 40 0 10 tons of limestone. : : : ° ; on 0) 87 12 Now the average market price of ferro-manganese at Pittsburg during 1901 to 1907 as quoted in the Engineering and Mining Journal is $6137 or Rs. 191-12. It would probably cost Rs. 18 to 20 to send the ferro-manganese from Sini to the European and American markets. Assuming the latter figure, the average value of the ferro at the works at Sini would be Rs. 171-12. The difference between this and Rs. 87-12, the cost of the materials, is Rs. 84. From this has to be deducted the costs of smelting the charge for the production of the ferro and all the other charges, such as depreciation on plant i The figure given me by Mr. H. Macleod, for 1907, when prices were high. ITI mM 2 ww 588 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Parr III: and interest on capital laid out. What is left after making this deduction is the approximate profit per ton of ferro-manganese manu- factured. I have no information as to costs of plant, smelting, etc., and consequently cannot give a figure for this deduction. The market price for pig iron in England in the early part of 1908 has ranged from 48 to 50 shillings ; this has of course to cover the manufacturer’s total costs of materials and smelting, interest on capital, etc., and his profit, though the latter may have been small at this time. Since ferro-manganese is smelted in a similar way to pig iron, even though the wear of the furnace is greater, and men who understand the manufacture of ferro may be able to command higher salaries, it is not probable that the deduction that has to be made from the figure of Rs. 84 given above is greater than Rs. 30, and not at all improbable that it is considerably less. Hence it will be seen that even though the figures I have given are very rough, yet there seems to be room for a handsome profit in manufacturing ferro-manganese in India; and it certainly looks as if it should be worth some one’s while to go seriously into the question. These two alloys, spiegeleisen and ferro-manganese, are used chiefly in the Bessemer and open-hearth processes for making both acid and basic mild steel. In all cases they are added at the end of the process. The alloy may either be charged direct into the furnace, orit may be put in the launder through which the molten metal runs on being tapped from the furnace into the casting ladle, or it may be put into the casting ladle itself. On account of the requisite time (5-12 minutes) and temperature conditions being obtained and a more thorough mixing being effected, with a consequent more uniform product, the first method is preferred by some.! The reason for the addition of the alloy is twofold :— Use of spiegeleisen and ferro-manganese. (1) To supply the carbon requisite to convert the metal, which has become decarburized in the furnace, into steel. (2) To remove the oxygen taken up by the bath of molten metal with the formation of oxide of iron. All the manganese concerned in this process of breaking up the iron ‘ car Meas : Quantity of manganese oxide passes into the slag as manganous oxide. required in the manufac- But, as will be seen from page 592, a certain pro- ture of steel. portion of manganese in the finished steel is 1 Jron and Steel Mag., 1X, May 1905, pp. 474—5. Cuap. XXVIII.] mManuractURE OF FERRO-MANGANESE. 589 beneficial ; hence it is necessary to add a quantity of alloy sufficient for some manganese to be left in the steel after the removal of the oxygen. Penrose says that the amount of the alloy added varies from 1 to 5% of the steel, according to its metallic contents, and according to the amount of manganese it is desired to leave in the steel. The amount left in ordinary mild steel, such as is used for rails, varies from less than 05% to over 2%, but is not as a rule much over 05%. As the man- ganese alloy always contains silicon and pligupliovens one other im- purities, the less of it that has to be added the better; also the less that has to be added the milder can the resulting steel be made. Hence high-grade ferro-manganese is usually preferred to the lower grade spiegeleisen. In paper on the covering of the demand for manganese-ores!, W. Venator takes an average consumption in the iron and steel industry of 1:3°/, of manganese as necessary per ton of steel nroduced, The 50,000,000 tons of steel produced by the world in 1906, would tkus account for a consumption of 650,000 tons of manganese, or 1,300,000 tons of 50°/, manganese-ore, out of the 1,445,000 tons of ore produced in that year. As regards the impurities permissible in the alloy used O. Simmers- Eieophamied and” silicon bach gives it as a rule that spiegeleisen with in spiegeleisen and ferro- 20° Mn should not contain more than 0:1% of _—o phosphorus, and for every 10% Mn above this the phosphorus contents should not increase by more than 0-02%, so that ferro- anaes with 80°, Mn should not contain more than 0-1+(6 x 0-02)—0-22% P. The standard for silicon is spiegeleisen containing 20% Mn Sait 1% Si with a permissible increase of 0-1% Si for every 10% increase in the manganese ; hence 80% ferro-manganese should not contain more than 1-:0+(6 x0-1)=1-6% silicon. From the above we see that ore of the composition given on page 586 should not, if it is to give 80°/, ferro, contain more than 0-116% or, say, 0-12% of phosphorus. The ave erage figure for phosphorus given there i is 0-10. This is possibly a trifle higher than that of the ore exported ; 0-08 to 0-09 would probably be a more accurate figure. The ores of the Central Provinces are therefore within the phosphorus limits necessary for high grade ferro. Of ores exported from other parts of India, those of Mysore and Sandur are well within the limits. But those of Jhabua (0°16-0:27% P) and the Panch Mahals (0°15-0:25% P) are over the limit, ane those of 1: Die Deckung des Bedarfs an Manganerzen °, ? Stahl. u. Eisen, XXvI, p. 66, (1906). 590 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Parr IIT: Vizagapatam (0°20-0°45% P) very much so. The question ther arises as to what use is made of these ores. Now for the preparation of 20% spiegel it would take “309 tons of manganese-ore of composition Manganese... 3 ce oe ecole p 140 tron eis ae as ss 2 10 assuming a loss of 25°% of manganese in smelting, to give one ton of 20% spiegel, the remainder of the charge being made up of iron-ore in requisite quantity (1°36 tons if containing 50% of iron, and the loss in smelting were nil), If the iron-ore were absolutely free from phosphorus then the maximum possible phosphorus in the manganese-ore, so that the spiegel should not contain more than 0:10% of phosphorus would be 0°18. Hence we see that some of the Jhdabua and Panch Mahals ores could be used for spiegel, but nut those of Vizagapatam. It is to be noted, however, that although Simmersbach gives 0:22 P as the upper limit that 80°% ferro-manganese should contain, he gives analyses of ferro-manganese from various localities showing 0:20-0°36% P with 76-85% Mn. Other analyses often show figures in excess of those given by Simmersbach as permissible. Thus Penrose gives analyses of spiegeleisen showing 0:002-0°196% P with 8-26% Mn; and analyses of ferro-manganese showing 0:005-0:-4719% P with 40-88% Mn. The above deductions as to the employment of the ores of Jhabua and the Panch Mahals should therefore be taken with reserve. I am told that a considerable proportion of the Indian phosphoric bbl, ae ' ores is used in the manufacture of basic mild Use of the Indian phos- : : phoric ores. steel] by the Thomas-Gilchrist process, and pro- bably in the basic open-hearth process as well ; but whether it is used in the manufacture of the pig required for this process or whether it is put into the charge in the steel furnace, I have not heard. In either case the excessive amount of phosphorus would pass into the slag along with the phosphorus derived from the iron-ores. For use in this way Indian phosphoric manganese-ores find their way to England, Germany, and America. Now manganese has a great affinity for sulphur and is consequently int __ used as a de-sulphurizer. I understand that a Use of manganese-ore for i E z Fs de-sulphurizing. considerable quantity of Indian phosphoric ore is used in the smelting of the highly phosphoric low-grade oolitic iron-ores (‘ minettes’) of Luxemburg and Lorraine, the manganese-ore being put into the blast-furnace charge ; the Cuar. XXVITI.] MANGANESE-STEEL. 59 product is a phosphoric nonsu!phurous pig, the manganese having com- bined with the sulphur, which I am told these ores contain in considerable quantity, and carried it into the slag. This pig is converted into steel by the basic process. There is also a process known as J. Massenez’ de-sulphurization process. In this the cast iron is tapped out of the furnace into a ladle or ‘mixer’ to which an iron-manganese alloy containing the required amount of manganese is added. On allowing to stand at rest for some time the manganese combines with the sulphur in the iron and floats to the surface, as manganese sulphide. The slag may be returned to the blast-furnace. when the greater part of the sulphur is eliminated and the manganese recovered.! Manganese is also sometimes used in foundry practice. The presence .... ., , ofmanganese in foundry pig, if not over 1 to 2%, mie pedo is beneficial, because it makes the pig harder and closer grained ; it is also indirectly useful because it prevents the absorption of su'phur from the coke during remelting. It may be added in the form of ferro-manganese or of ore.2 When added -in small quantities to the molten metal in a foundry ladle the immediate effect may be the softening of the iron, owing to the manganese elimina- ting the sulphur and counteracting the effect of silicon.? Manganese-steel contains a considerably higher percentage of man- ganese than is present in all ordinary steels. Proportions of manganese from 1 to 7% are said to render steel brittle ; but when the manganese is present in the pro- portions of 7 to 30% the steel becomes remarkably strong and ductile, both toughness and ductility being increased without loss of hardness, by heating to a yellow or white heat and quenching in water. Manganese- steel thus contrasts with carbon steel ; for in the latter great hardness is produced only on quenching and is accompanied by brittleness and less ductility. Besides combining great toughness with great hardness, manga- nese-steel is practically non-magnetic. It is also remarkable for its ex- tremely low electric conductivity, so that it might be used for resistance coils. It is also a very bad conductor of heat. These alloys were investi- gated by Hadfield, who patented steel with amounts of manganese between 7 and 20%. The well-known Hadfield = Steel is said to contain are Manganese-steel. 1 Turner, ‘ Metallurgy of. Tron ’, pp- 151- 2, , (1895). J 2 F. Wiist, Jour. Iron Steel Insk, 1903, No. IL, pp. 646-8. 3 Turner, loc. cit., p. 205 592 MANGANESE DEPOSITS OF INDIA: EcoNoMicS. [ Parr III: 13% of manganese and 1% carbon. Although, on account of its hardness, very difficult to work, manganese-steel is now being used extensively for many purposes where combined hardness, toughness, and consequent great ability to resist grinding wear, are required. Among such appli- cations may be mentioned all kinds of mining machinery, especially that used for crushing and milling, such as the jaws of rock-breakers, crusher- heads, rolls, etc., and also mine-car wheels, dredging machinery, and safes. Manganese-steel rails are used in America on the Boston Elevated Rail- way! wherever there are sharp curves,with consequent great wear of the rails. The manganese-steel rails are found to be more economical than either carbon-steel or nickel-steel rails, owing to their excessively slow rate of wear. Manganese-steel has also been used for tools, such as axes and razors. The above gives only a brief outline of the uses of manganese in the metallurgy of iron and steel. The effects of man- Effects of manganese on on aecel ganese on iron and steel have been summarized by H. M, Howe 2 as follows :— ‘It is easily removed from iron by oxidation, being oxidized even by silica, and partly in this way partly in others it restrains the oxidation of the iron, while some- times restraining sometimes permitting the oxidation of the other elements com- bined with it. It is also apparently removed from iron by volatilization. Its presence increases the power of carbon to combine with iron at very high tempera- tures (say 1400°C ), and restrains its separation as graphite at lower ones...... ee Baa ae By preventing ebullition during solidification and the formation of blow- holes, by reducing or removing oxide and silicate of iron, by bodily removing sulphur from cast-iron and probably from steel, by counteracting the effects of the sulphur which remains as well as of iron-oxide, phosphorus, copper, silica and silicates, and perhaps in other ways, it prevents hot-shortness, both red and yellow. (It does not however counteract the cold-shortness caused by phosphorus.) These effects are so valuable that it is to-day well nigh indispensable, though admirable steel was made before its use was introduced by Josiah Marshall Heath 3. It is thought to increase tensile strength slightly, hardness proper, and fluidity, to raise the elastic limit, and, at least when present in considerable quantity, to di- minish fusibility. It is generally thought to diminish ductility : evidence will be offered tending to show that its effects in this respect have been exaggerated. While 1°5 to 2°59 of manganese is nearly universally admitted to cause brittleness, steel with 8% of manganese is astonishingly ductile: with further increase of manganese the ductility again diminishes. Steel with 8 to 10° manganese, though extremely tough, is so hard as to be employed without quenching for cutting-tools. It is denied and asserted with equal positiveness that manganese confers the power of becoming harder when suddenly cooled, but it is generally thought to make steel crack when quenched.’ 1 [ron and Steel Mag., 1X, pp. 476-481, .May 1905. Abstracted from Railroad Gazelte, March 17, 1905. 2° The Metallurgy of Steel ’, I, p. 42, (1891). 3 Percy: Iron and Steel, p. 840. Cuar. XXVIII.] MANGANESE IN IRON AND STEEL. 593 Roberts-Austen explains the effect of manganese on steel in the following manner :— Manganese having a lower atomic volume (6-9) than iron (7-2) delays during cooling the change from the 8, or hard allotropic variety of iron into the a, or soft variety, as well as that of hardening carbon into carbide carbon. Hence with equal rates of cooling it tends to increase the pro- portion of B-iron present in cooled iron and steel, and consequently the hardness of the metal!. ‘Speaking generally, if the steel contains, in addition to carbon, a per cent. of manganese, each class of steel would be equivalent, as regards tenacity and hardening properties, to the one above it’, 7.e., it would be equivalent to a steel with more carbon 2. Above 7% of manganese appears to prevent entirely the passage of B-iron into q-iron, and since B-iron cannot be magnetized—the temperature of recalescence, at which iron in cooling down changes from the B to the a form, being also that at which iron on heating up looses the power of being magnetized and passes from the « to the 8 form-—--, steels with over 7% of manganese are non-magnetizable. Ewing concludes that ‘no magnetising force to which the metal is likely to be subjected, in any of its practical applications, would produce more than the most infini- tesimal degree of magnetisation ’ in Hadfield’s manganese-steel.? That high manganese may to a certain extent counteract the deleterious effects of phosphorus is explained by the fact that the manganese phosphide has the formula MngPs5, whilst that of the iron phosphide is FesP, so that the manganese can take up twice as much phosphorus as the iron. When in the phosphide condition the phosphorus is less injurious to the mechanical properties of the steel than when evenly disseminated through the steel.4 Hadfield® has recently patented a manganese-steel containing 10-40°/, manganese and less than 1% carbon. It is prepared by the addition to decarburized iron of ferro-manganese, made in the electric furnace, and containing only 2-3% of carbon. Owing to the compara- tively low percentage of carbon in the steel, it is less lable to fracture during treatment. It is also distinguished by its relatively strong magnetic characters. 1 ‘ Introduction to the Study of Metallurgy ’, p. 121, (1902). 2 Loc. cit., p. 176. 3 Loc cst., ps li. 4 J. A. Mathews, ‘ Mineral Industry ’, XI. p. 673. 5 Llectrochemical and Metallurgical Indusiry, July 1907, p. 283. 594 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part III: In addition to spiegeleisen and ferro-manganese there is a large number of other alloys containing manganese,! An interesting account of the alloys containing manganese is given by Penrose in his book on manganese, and to this reference may be made. Since this was written, however, much work has been done on alloys containing manganese. Attention may be drawn to Heusler’s magnetic alloy of copper, manganese, and aluminium2, and to Guillet’s work on nickel-manganese steels.3 The only alloys that can be mentioned here in addition to those already noticed are silicon-spiegel and manganese-bronze. Other manganese alloys: For some purposes alloys of iron rich in both manganese and silicon are required. Such alloys are known as sélicon- spregel and silicon-ferro-manganese. An example of silicon-spiegel is an alloy containing 10% silicon and 209% manga. nese. The name manganese-bronze is applied to alloys of manganese and copper, sometimes with iron as well. In commerce there are now two grades of metal. One is a mixture used for rolling into sheet, or drawing into wire or tubes, and also for forging. It contains no aluminium and cannot be cast in sand. The other grade contains aluminium, and is suitable for sand-casting, being largely used for the manufacture of ship’s propellers. Both these grades apparently also contain zinc.4 Manganese-bronze is distinguished by a remarkable strength, toughness, and hardness, and by a non-liability to corrosion by sea-water; hence its use for propellers. Silicon-spiegel. Manganese-bronze. Metallic manganese also is now manufactured on a commercial scale, namely at Essen in Germany, the Goldschmidt process of reduction by aluminium being used, Owing to its high cost as compared with ferro-manganese (about 10 to 1) its use is limited mainly to the manufacture of copper and other special alloys5. The price is quoted in the Engineering and Mining Journal for January 25th, 1908, page 239, as 75 cents per lb., at New York, for metal containing 98-99 °% Mn. Metallic manganese. 1 In the Jron and Coal Trades Review, June 29th, 1906, pp. 2316, 2317, there is an interesting article entitled ‘ Some Uses of Pure Manganese and its Alloys.’ 2 Eng. Mining Journal, 13th Jan. 1906, p. 84: B. V. Hill, Electrician, Nov. 24, 1905 ; A. D. Ross, Proc. Roy. Soc. Edin., XX VII, pp. 88-92, (1907). 3 Revue de Métallurgie, Nov. 1905. Abstract in Iron and Steel Mag., XI, April 1906, », 329. 4 Hng. Mining Jour., 8th Sept. 1906, p. 458. 5 ‘Mineral Industry ’, X, p. 441, (1901). Cuap. XXVIII.] sMeELTING MANGANESE-ORES IN INDIA. 595 Tron-ores occur in great abundance in many parts of India and have Wie een ck snange- been smelted from time immemorial by the nese-ores by the natives of natives. It is interesting to note that in some — cases the ores smelted have been mangani- ferous, sometimes highly so. Whether the use of manganiferous ores was dependent on local occurrence and hence merely accidental, it is difficult to say. But, judging from the fact that in some cases true manganese-ores have been mixed in with iron-ores in the furnace, it seems probable that in these cases at least the native smelters have recognized that the addition of this constituent has some beneficial effect on the quality of the iron produced. Thus | found that the Dhavads or iron-smelters of Mahdbaleshwar in the Western Ghats have a separate name—zaral—for manganese-ore, and that in former days, before smelting was stopped here on account of the damage done to the forests, some of the manganese-ore was used in the charge. This was on the authority of two Dhavads who had formerly smelted in the times when this industry was flourishing. A writer in the Indo- European Commercial Trade Register! refers to a tradition amongst the Dhavads that the Pheenicians used to carry away manganese-ores. Mr. H. G. Turner, taking as his evidence the occurrence of vestiges of furnaces close to Garbham Hill?, says that the manganese-ores of Garbham in the Vizagapatam district were formerly worked by the native smelters. The example best known in India is the smelting that at present goes on at Ghogra in the Jabalpur district. Here a manganiferous iron-ore is smelt- ed in small native iron-furnaces ; the product is a rather hard steely iron known as kheri, and is in great demand in the surrounding country, where the Johars or blacksmiths weld it on to ordinary country-made soft iron to form the edges of axes and scythes, the striking faces of hammers, and the heads of anvils. As an example of the demand for this metal I may mention that when I was at Ghogra I found some blacksmiths who had come all the way from Rewah simply to get a fresh stock of this kheri. The ore from which the iron is smelted is a manganiferous micaceous hematite, the manganese occurring as veinlets and films of psilomelane in the hematite, into which it has been secondarily introduced. Some of the ore I saw being selected for smelting was pure psilomelane, however. The shallow pits from which the ore is obtained are in Dhanwahi village limits. Mallet Kheri. I, p. 47, (1907). Jour. Iron Steel Inst.. No. I for 1896, p. 160. 1 2 596 MANGANESE DEPOSITS OF INDIA: EcoNoMIcs. [Parr III: some years ago took a sample from the whole of these pits and obtained the following result on analysis?:— Manganese 12-262 fron 46°43 Silica, ete. 9°55 Phosphorus 0-19 Sulphur trace When at Jauli, in the same districé, | took a sample of the soft hematite being smelted there for the production of the soft iron on to which the khert is welded. Newcastle, is given below :— The analysis, made by Messrs. J. & H. 8. Pattinson of Sample No. A. 10. Manganese 0-16 Iron 59°90 Silica . 5°80 Phosphorus ; 0-043 Samples taken from the rough blooms of kheri and soft iron produced from these ores were analysed by the same firm of analysts with the follow- ing results :— TABLE 89, Analyses of native-made trons. ra Kheri from Soft iron from Tron shot from Ghogra. Jauli. Jauli. Tron 98-253 99247 95-407 Manganese 0296 trace 0-086 Carbon 1-214 0°378 3°918 Silicon 0-095 0°327 0°235 Phosphorus | 07140 0-039 0°333 Sulphur 9002 | 0-009 0-021 | 100-000 100:000 | 100-000 The third sample represents some round shot found amongst the ashes and charcoal left after the bloom has been taken out of the furnace. From these analyses it will be seen that the superior hardness of the kheri over the soft iron can hardly be attributed to the 0-3% of mangan- ese it contains ; but must rather be attributed to the larger amount of carbon. The manganese has no doubt had a purifying effect on the kheri 1 Rec. G. S. I., XVI, p. 101, (1883). 2 Contains traces of cobalt. Cuap. XXVIII.] USE AS AN OXIDIZER. 597 in the same way as in the manufacture of mild steel, whilst the manganese left in the kheri may exert some effect in keeping the carbon in the com- bined condition. It is to be noted, however, that although the kheri is much superior in hardness to the soft iron, so that the faces of the hammers and anvils assume a smooth shining mirror-like appearance under the influence of constant impact, yet one of these shining surfaces was easily dented by the corner of my geological hammer. Of the man- ganese in the iron-ore from which the soft iron is manufactured, it will be seen that practically all has left the iron and has hence passed into the slag, except for a small portion found in the shot. TI did not see the use to which the shot are put, but I was told that they are made into plough-shares, the iron thus made being harder than the soft iron, but more liable to break. If the composition of the finished metal be like that of shown by the analysis, the ploughshare metal must be interme- diate between cast iron and steel. An account of the manufacture of kheri is given by P. N. Bosel. Use as an Oxidizer. We can now turn to the use of manganese-ore as an oxidizer. For this purpose the value of the ore does not depend on the amount of manganese it contains, but on the amount of available oxygen, i.e., oxygen that can be obtained from it by the action of acids. This available oxygen is usually stated in terms of manganese peroxide (MnO,). The mineral containing the largest amount of MnO, is of course pyrolusite, which when pure consists of 100% of MnQ,.2 Psilomelane, also, often contains a considerable quantity of MnOg. Psilomelane is, as noted in ChapterIV, amanganate corresponding to the general formula R,MnO;. If the R consisted entirely of manganese, giving a formula for the mineral of Mn MnO;, then the amount of MnO, present in the theoretically pure mineral would be 77:33%. Going to the other extreme, if the R consisted entirely of hydrogen, a condition not approached even nearly in Nature, then the formula of the compound would be H,MnO;, and the amount of MnOg in the theoretically pure compound would be only 62°579%. But it will be seen that after deducting 2H,0 | the radicle MnOz ig left; in this case, therefore, it would be misleading to state Use of manganese as an oxidizer. 1 Rec. G. 8. I., XXI, pp. 87, 88, (1888). 2 Polianite also has this formula, MnOg, but it is too rare to be considered commer- cially, 598 MANGANESE DEPOSITS OF INDIA: ECONOMICS. [Part ITI: the available oxygen in terms of MnQg, the amount of available oxygen being in fact equivalent to 2 x 62-57% of MnO,. On the assumption of R_ being entirely Ba, so that the formula would be Ba,MnO;, the MnO, works out at 21-23%, but the available oxygen is equivalent to 2X 21°23= 42-46% MnO». Hence it will be more convenient to state the available oxygen as such in the way given below :— TABLE 90. Available oxygen and manganese peroxide present in pyrolusite, psilo- melane, and hollandite. Pyrolusite. Psilomelane (and hollandite). Formula. 7 i - se MnOp2. | BaoMnO; Mn2Mn0O3. HgMn0Os. Available oxygen. - 18°39 7°81 13°06 23°01 MnO2 equivalent of avail- | able oxygen : . | 100°00 42-46 77°33 125714 MnOg present . 5 . 100-00 21-23 TPIS 62°57 From this it will be seen that in theoretically pure psilomelanes the amount of available oxygen should range between the limits of 7-81 and 23-01, Since in most psilomelanes the bulk of the R group is manganese, the majority of psilomelanes should range round 13% in their available oxygen, this corresponding to about 77% of MnO,. Allowing for the fact that most psilomelanes contain a little mechanically-included im- purity these figures would be in actual practice a little less than 13 and 77, respectively. The 5 analyses of psilomelane given in Chapter TV show 70-78 to 83-13% MnOoz, whilst the 12 calculated analyses show from 73-14 to 84-1294 MnO,. The four analyses of hollandite, to which the foregoing figures as to composition also apply, show 65°63 to 75°059% MnOp. As is shown below the other ores of manganese contain much smaller amounts of MnO;: °% MnOs. Manganite - ; : - ; : . 49-44 Braunite . : z E E 3 2 Z : : : 43-11 Hausmannite . . : é - - : : ; : 37°99 Rhodochrozite . r P > Nil. The standard ore for een purposes is that containing 70% MnO, equivalent to 44-259 manganese, and below this limit there i is not much demand for ores for these purposes. Hence we see that for chemical] Cuapr. XXVIII.) USE AS AN OXIDIZER. 599 purposes the best ore is pyrolusite, but that psilomelane is often good enough ; whilst the other ordinary ores of manganese are of little or no use, The chief chemical use of manganese-ore is for the manufacture of chlorine, and before the use of manganese in the metallurgy of iron and steel, this accounted for by far the larger proportion of the consumption of manganese-ore. (Of recent years, however, the demand for manganese- ores for the manufacture of chlorine has decreased owing to the manu- facture of chlorine electrolytically. For chlorine manufacture not only must the ore be as high in MnOg as possible, but the impurities making up the remainder of the ore shculd be such as are insoluble in hydro- chloric acid. Thus ore containing 75°, manganese peroxide would be of more value if the remaining 259% were quartz, than if it were iron oxide or carbonates. Owing to the fact that soft ores are more quickly attacked by acid than hard ones, pyrolusite is preferable to psilomelane, even when the two contain the same percentage of MnOy. There are many deposits in India where a fair quantity of pyrolusite, ranging over 70% of MnOg, can be obtained ; and at times Indian pyrolusitic ores have been sold for chemical purposes. Thus some of the Kodur pyrolusite is said to have been bagged and sold for this purpose, as also has some of the Mysore ores. The analysis of a picked specimen of Kodur pyrolusite given on page 82, shows 92-31% MnO,: whilst bulk samples of pyrolusitic ores from Bankuravalsa and Sandanandapuram in the same _ district show 71°64 and 72°03 MnO, respectively (see pages 1105 and 1076). And if it were specially required I believe that at several localities a product of over 80% of MnO, could be sorted. It must be remembered that ore sold for its MnO, contents fetches a much higher price than if sold for its manganese contents. In the following table the figures given in the first and second columns are taken from the Engineering and Mining Journal for August 3, 1907, page 236, and refer to crude powdered ore. In the third column I have converted the price in cents per pound into sterling per ton :— TABLE 9}. Prices of manganese-ores sold for peroride. Percentage of MnOz. Cents per pound. Sterling per ton. £s. d Er Rade 70-75 14-12 516 8to 7 0 0 75-85 14-2 70 0to 9 6 8 85-90 12-5 8 3 4to 23 6 § 90-95 63 worth £30 6 8 600 MANGANESE DEPOSITS OF INDIA: EcoNoMIcS. [Part III: When it is remembered that even if the ore contained 95% MnOs, which is equivalent to 60% of manganese, and were sold for its manganese at 16 pence per unit, it would fetch only £4 a ton, z.e., less than ore con- taining only 70% of MnO, equivalent to only 44% manganese, if sold for its MnOs, it will be seen that the extra cost of bagging the ore would be handsomely repaid ; and considering the great increase in the price for the higher grades, it would probably pay to concentrate the ore before shipping. Another use to which manganese-ore is put on account of its oxidizing power is the decolourization of glassl, from which it removes the green colour due to ferrous iron. Pyrolusite for this purpose must be extremely pure—iron being of course a very deleterious con- stituent—and fetches a very high price. The only pyrolusite sufficiently pure for this purpose, yet found in any quantity in India, is that of Pali in the Nagpur district. A picked specimen of this (see No. 932 on page 82) yielded on analysis 95-57% MnO, with only 0-06% Fe,03. Of ore similar to this, a sufficient quantity could probably be won to pay handsomely for the treuble of extracting it from the limestone in which it occurs in scattered pockets. A bulk sample of ore not specially selected for this purpose gave 72-71% MnOg, with still only 2-98% Fe,0s. A well-known region from which high-grade pyrolusite has long been * obtained suitable for use for chemical purposes and for the glass industry is Nova Scotia and New Brunswick. Some of the ores from this region are exceptionally high in MnO, and low in iron. The less pure ores are often prepared for the market by crushing, washing, and sizing with screens, To give an idea of the high prices that the Canadian ores fetch I give below a table showing the official statistics for the quantity and value of the Canadian production of manganese-ore from the years 1893 to 1905 ; the values per ton for each year are shown in the last column. It will be seen from this that the value of the Canadian ores has fluctuated during this period from a maximum of £19-12-3 per ton in 1893 to a minimum of £2-5-74 in 1901, the value for the last year for which I have Use of manganese for the decolourization of glass. 0-49%, of iron oxide, Cuar. XXVIII.| UsE As COLOURING MATERIAL. 601 obtained figures being £16-5-9. The violent fluctuations are probably due to great variations in the quality of the ore, rather than to vari- ations in price. And it must be remembered that the price for any given year is probably below that of tlie best ore, because the value is calculated on the whole of the ore produced. TABLE 92. Quantity and value of the Canadian manganese-ore production from 1893 to 1905. Quantity. Total value. | Value per ton. Tons. $ $ 1893 133 12,521 94-14 1894 56 } 3,120 55°71 1895 108-3 | 6,351 58-64 1896 123-5 | 3,975 32-19 1897 15+25 1,166 76-46 1898 1l 325 29-55 1899 70 2,410 34-43 1900 34 | 1,720 50°59 1901 440 | 4,820 10-95 1902 172 4,062 23-62 1903 135 1,889 13-99 1904 123 | 2,706 22-00 1905 22 | 1,720 78:18 Manganese-ore might also be used for the preparation of bleaching powder in India, for which there would pro- ee ese eee for bably be a demand from the India bleaching powder, bullion > n paper melting, and potassium mills. J also understand that manganese ia tcanaa peroxide has been used on the Kolar Gold Field to assist in the oxidation of the zinc when the auriferous preci- pitates obtained in the cyanide process from the zinc boxes are being converted into bullion. Large quantities of potassium permanganate are used in India as a disinfectant. It is a pity that this material should be imported when the material, namely manganese-ore, from which it is made, exists in such abundance in India. Use as a Colouring Material. From very early times there has probably been a small consumption at ee of manganese-ore by the natives of India colouring glasses and ena- for colouring glasses and enamels, it being mels. possible to impart green, violet, brown, and u N 602 MANGANESE DEPOSITS OF INDIA: Economics. [ParTIII: black tints by the use ofthis substance. According to Sir George Watt! the colours in the Indian enamels are invariably due to borates and silicates of the metals, manganese carbonate being used to produce violet. The pyrolusite of Gosalpur in the Jabalpur district is supposed to have been worked from ancient times for use by glass-workers as a colouring material, Watt2 gives an interesting account Use of manganese for of the ornamentation of the pottery of Pesha- pottery. war. He says; “The pottery of this northern town has been spoken of as resembling majolica. It is a rough “ fuience”. The reddish earth body or “ paste” is coated with a dressing in white earth—the “slip ” or “‘ engobe”’ which consists of a preparation of karia mitti or chalk, obtained from the Khaibar. It is then dipped into the glaze of which the basis is lead oxide. For the ordinary greenish white pottery, nothing else is needed. But when it is desired to ornament the plate or jar, the design is outlined on the un- burnt glaze, with a paint made of manganese, and the details are filled in with a preparation of copper. When burned, green leaves, outlined in brown, are produced on a dirty white. Sometimes the glaze is more thoroughly fused and the colours then run and the brown takes a purplish tint. Further colours are red, obtained from a red earth, and black, from a stone of dark colour—both procured from the Khaibar. ’ The dark ore last referred to may very well be an ore of manganese, At Raniganj, Messrs. Burn & Co. use manganese-ore to a small extent for imparting dark brown and black body colours to tiles and pottery, and also for imparting dark brown and black glazes to ordinary biscuit-ware. Formerly, inferior black tiles were produced without the use of manganese, the black colour being obtained by using disintegrated laterite with a little salt—not enough to glaze—added at a high heat, a reducing atmosphere being maintained. But about 20 years ago the use of manganese-ore was begun with the production of a very superior black colour. The mixture used by Messrs. Burn & Co. in 1904 for producing black tiles is the following :— Parts by measure. Black biscuit . - : - - ¢ : S < 3 Kankar 3 : : 5 0 < : - 2 Durgapur clay . : . c : : . . : 2 Manganese-ore . : ° . 5 ° . : F 3 Felspar . . ° ; : : ° : : ° 2 The material all passes a sieve of 40 holes to the linear inch. By using 2 Loc. cit., p. 89. 8 Really disintegrated laterite. Cuap. XXVIII.] usE as coLOURING MATERIAL. 603 The next recipe is that in use for a black body clay for plaster moulds and the potter’s wheel :— Recipe No. 63. Perts by measure. Black broken pipes : - : : : Uncalcined kankar 1 : - - - ; . Durgapur clay Giri mati (red ochreous clay) Manganese-ore . Then take of Recipe No. 63 : : : : - - - 3 Felspar and biscuit eed 1 The materials are all passed through a nitial yaaienall ail sieve of 120 holes to the linearinch. This latter recipe is used for producing statuary, vases, jeroboams, and other ornamental ware. When unglazed this ware is very similar in colour to psilomelaue, emits a heil-like sound when struck, and is extremely hard and tough. Just the merest trace of glazing changes the colour to slaty-black, and when adorned with silver monogram, or other silver ornamentation, articles of this ware are ex- ceedingly handsome. RSrmonwnw Manganese-ore is also used for glazing terra-cotta biscuit-ware, the colour produced varying, according to the proportion of ore used, from chocolate to pure black. The following recipe is one now in use for im- parting a deep brown glaze to such articles as teapots, chilams, and hookahs :— Parts by weight White lead. : : : - ; : ; : 124 Cornish stone 2 3 Calcined English flint 24 Manganese-ore . 24 Durgapur clay . 13 By increasing the proportion of manganese-ore a dee black colour is obtained. Articles—presented by Mr. A. Whyte of Messrs. Burn & Co., to whom I am indebted for the foregoing information—illustrating the foregoing recipes will be found in the Geological Museum. The ore used is all obtained from the neighbourhood of Sihora and Gosalpur in the Jabalpur district. The pyrolusite and psilomelane of this district are often mixed with quartz and clay ; but these foreign materials do not spoil the ore for pottery purposes, for which it need not be particularly pure. 1 Re ally disintegrated laterite. 2 Residue from Cornish kaolin. 604 MANGANESE DEPOSITS OF INDIA: Economics. [Part III: Ornamental applications. In addition to the manganese-ores proper, use might also be made of two of the Indian silicate minerals of manganese, In my paper ‘Manganese in India’, p. 1201, I wrote :— ‘ Moreover, I would draw attention to the fact that many of the manganese- ore deposits of the Central Provinces contain considerable quantities of rhodonite, at present being consigned to the dump-heap ; but that the rhodonite from other parts of the world, especially the Ural Mountains, is often used as an ornamental ston>. It would be difficult to find a more beautiful ornamental stone than the pink rhcdonite with delicate veins of black manganes2-oxide, such as occurs at Manegacn, Nagpur district, or than the rhodonite studded with orange spessartite, such es ‘s found at Chargaon, Nagpur district, and in the Chhindwara district. In the United States, moreover, spessartite when found clear and transparent is sometimes turned to account as a very beautiful gem-stone of orange and red colours. Ihave not seen any Indian spessartite, except very small crystals, sufficiently clear for this purpose, but it is as well to keep it in view’. Since this was written Mr. H. D. Coggan, Manager of the Central India Mining Company, has kindly tried to obtain some large specimens of the rhodonity found in the Manegdon deposit referred to above. He was not able to obtain anywhere pieces of rhodonite large enough for such purposes as the manufacture of small table-tops, because the rock was too much altered into manganese-ore. The specimens he obtained were nearly all of them interbanded with spessartite-rock, so that it would be difficult to select a piece of rhodonite more than 6 inches across. But it the banded rock could be used, fairly large pieces of rock might be obtained. As it is, however, a considerable supply of small pieces up to 5 inches across could easily be obtained, should anyone wish to start an industry for making small ornamental objects from rhodonite. And until some of the other deposits containing abundance of rhodonite have been carefully exploited, I shall not take it as demonstrated that it is impossible to obtain in India moderately large pieces of rhodonite suitable for ornamental work. 1 Trans. Min. Geol. Inst. Ind., 1, (1906). 2 Kunz; *‘ Gems and Precious Stones of North Ameriza’, p. 79, (1890). APPENDIX TO PARTS I, II, AND III. 605 APPENDIX TO PARTS I, Il, AND Ill. In this appendix I propose to give some figures that I have found extremely useful in making the calculation involved in turning analyses of minerals and ores into terms of their mineralogical composition, and in other calculations. The atomic weights used throughout this Memoir are shown below :— List of atomic weights. Aluminium s - 3 - : : , 2 204 Arsenic . 2 - - 2 - - 2 Ae FEL Barium . ~ : 2 ; : = - . 137°4 Calcium . = “ ~ : : - : - 40-0 Carbon . - : : : ; a =) 12-0 Chlorine . : - - : 5 . = . 30°45 Cobalt . 5 - - - Ps A . 59-0 Copper . = 2 - - - . - - 63°6 Fluorine . - - ‘ : i - A . 19°0 Hydrogen . : - - - F ; : 1-01 Tron . . . . . . ° . - 56:0 Lead ° ° ° 4 ° - “ 206-9 Magnesium - A - - : - : . 24°36 Manganese - 4 - 2 : - - - 55°0 Nickel . - = - - : - - - 58°7 Oxygen . . : ° . - : - ry ed GA, Phosphorus. - ° : . ° 4 - .oL0 Potassium - - - - - - ° ae SRT Silicon . . - : : - = - - 28°4 Sodium . 2 2 - 2 2 2 5 - 23°05 Zine A - ° - ° . ° - 65°4 606 MANGANESE DEPOSITS OF INDIA. Table showing the composition of certain manganese minerals. Name of mineral. Manganositej] . | Hausmannite (Manganese sesquioxide). Psilomelane ? . (Pyrolusite and polianite). Manganite (Manganic manga- nate). (Manganese trioxide) Braunite Rhodonite Rhodochrosite Spessartite Formula of mineral or compound, MnO Mn,0,4 . Mn,.03 Mn,0; (2Mn0.Mn0,) MnO, Mn,0;.H,0 2Mn,0,.3Mn0, MnO, $Mn,0,.MnSi0, MnsiO, MnCO, . 3Mn0.A1,03.35i0, . Log. of P ee per cent. Mn of r Mn. 77°46 | 1°8891 72°05 | 1°8576 69°62 | 1°8427 67°35 | 1°8283 63°22 | 1°8009 62°50 | 1°7959 61°60 | 1°7896 53°40 | 1°7275 63°59 | 1°8034 41°86 | 1°6218 47°83 | 1°6797 33°24 | 1°5217 | f Per cent. ot Log. of oxygen : Per cent. of oe ee eens other e : i a oxygen constituents. Mn. 22°54 | 1°3530 27°95 | 1°4464 30°38 | 1°4826 32°65 | 1°5139 36°78 | 1°5656 27°27 | 1°4357 | H,O = 10.23. 38°40 | 1°5843 46°60 | 1°6684 26°43 | 1°4221 | Si0,'= 9.95. 12°18 | 1:0856 | SiO, = 45.96. 13°91 | 1:1433 | CO, = 38.26. 9-67 | 0:9854 | SiO, = 36.50; Al,Qg = 20.59. List showing composition of certain manganese minerals in terms of oxides. Hausmannite (Mn,0,) 5 Manganese sesquioride (Mn,0,)] Psilomelane (*) or manganous manganate ° . (Mn,MnO,) MnO Mn,0, 2 MnO MnO, 31:00 or 2 MnO =) 62-01 69-00 MnO, =i oleae 100-00 100-00 ~ : MnO = 44:94 . MnO, 55°06 100-00 57°96 or 2 MnO = 28:98 42-04 MnO, = 702 100-00 100-00 APPENDIX TO PARTS I, HU, AND Il. Manganic manganate (2Mn,0, .3Mn0O,) Manganite . . . (Mn,0,.H,0) Braunite . - ° (3Mn,03.MnSi03) Rhodonite . = ° (MnSi0,) Rhodochrosite . 2 (MnCO.,) Spessartite (3Mn0.A1,0,.3Si0,) 2 Mn,O, 3 MnO3 50°56 or 49°44 100-00 89°76 or 10°24 100-00 718-29 11-73 9-98 100-00 54:03 45°97 100-00 61:74 38°26 100-00 or MnO MnO, SiO, 608 MANGANESE DEPOSITS OF INDIA. List of factors for psilomelane and hollandite. "multiplier. To form Fe(MnO,), 2 Fe,O,require 2x0-9656 MnO,. | — 1-9848 Fe,MnO, x FeO zX0-7153 ; 1°8545 Al,(Mn0,), z Al,O, ax1-512 : 0-1796 Ba,MnO, z BaO aX 0°3357 1-5260 Ca,MnO, x CaO xx0-9196 1°9636 Mg,MnO, a MgO xXx 1-276 : 01058 K,Mn0, z K,O zx 0°5461 ; 1°7373 Na,Mn0, a Na,O ax X 0°8293 ; 1°9187 Co,MnO, az CoO ax X 06867 1°8368 Ni,Mn0O, a NiO xX 06894 : 1°8385 Cu,Mn0O, x CuO xx 0°6470 $ 1°8109 Pb,MnO, x PbO aX 0°2310 : 13636 ZnMn0, x ZnO x X 0° 6327 - 1°8012 H,MnO, « H,O aX 2°858 : 0-4561 Mn,Mn0O, a MnO aX 0°7254 : 1°8606 Mn,(Mn0,), a Mn,O, x X0:9778 : 1-9903 a APPENDIX To PARTS I, II, AND III. 609 Figures for the conversion of phosphoric oxide into phosphorus. Ill 10) 610 MANGANESE DEPOSITS OF INDIA. Miscellaneous factors. Logarithm. For braunite, multiply combined SiO, by 4°320 fer the MnO, .. 6355 ” 9 4°700" .,,- pMBDT 6722 For apatite, 1 of P,O, requires 1°314 CaO (including as CaO the CaCl, or CaF,). To calculate chlorine or fluorine required multiply :— For Cl, For F. P.O, by 1664 -08929 - 1266 -06786 CaO by 5 ; - ° : ; For oxygen required to form Mn,MnO,, multiply % Mn by 2% = '4848, of which the logarithm is 1° 68556. Tons and Poods. 1 Longton = 2240 lbs. 1 Metric ton = 1000 kilogrammes = 2204: 62 lbs, 1 Short ton = 2000 Ibs. 1 Pood = 36°113 lbs. 1 Metric ton = 61°048 poods, To convert long tons to metric tops multiply by 1°01605 of which log is 0:0069151 as short tons ,, metric tons oF 0°90718 7 T°9576935 D poods s» metric tons ae 0°0163806 > 2 °2143272 poods » long tons as 0°0161219 ” 2° 2074163 CALCUTTA : PRINTED BY SUPDT. GOVT. PRINTING, INDIA, 8, HASTINGS STREET. Tir NEW YORK & ltt US te > e %.4 AC? t : ; Y C - S C2 RE NCES. MEMOIRS OF THE GEOLOGICAL SURVEY OF INDIA. VOLUME XXXVII. THE MANGANESE-ORE DEPOSITS, OF INDIA, dy L. LEIGH FERMOR, A.R.S.M., B.Sc. (LONDON), F.G.S., Asszstant Superintendent, Geological Survey of India. PART I: INTRODUCTION AND MINERALOGY. Published by order of the Government of India. 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IV.}—INDIAN PRE-TERTIARY VERTEBRATA. pp. vi, 137, pls. 26. 1865-85 Pt. 1 (1865); The Vertebrate Fossils from the Panchet rocks, by T. H. Huxtey. Pt. 2 (1878) ; The Vertebrate Fossils of the Kota-Maleri Group, by Sm P. pe M. Grey Ecerton, L. C. Mratt, and W. T. Branrorp. Pt. 3 (1879); Reptilia and Batrachia, by R. Lyprxker. Pt. 4 (1885); The Labyrinthodont from the Bijori group, by R. LypexKer. Pt. 5 (1885); The Reptilia and Amphibia of the Maleri and Denwa groups, by R. LypDEKKER. Vou. Lal ? (Sex. X.)—INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA, by R. LYDEKKER, except Vou. I, Pr. 1, by R. B. FOOTE. Vor. 1, pp. xxx, 300, pls. 50. 1874-80. Pt. 1; Rhinoceros deccanensis. Pt. 2; Molar teeth and other remains of Mammalia. Pt. 3; Crania of. Ruminants. Pt. 4; Supplement to Pt. 3. Pt. 5; Siwalik and Narbada Proboscidia. 4 ~ Vou. II, pp. xv, Ge pls. 45. 1881-84. Pt. 1; Siwalik Rhinocerotide. Pt. 2: Supple- ment to Siwalik and Narbada Proboscidia. Pt 3; Siwalik and Narbada Equide. Pt. 4; Siwalik Camelopardalide. Pt. 5; Siwalik Selenodont Suina, etc. Pt. 6; Siwalik and Narbada Carnivora. Vou. III, pp. xxiv, 264, pls. 38. 1884-86. Pt. 1; Additional Siwalik Perissodactyla ané Proboscidia. Pt. 2; Siwalik and Narbada Bunodont Suina. Pt. 3; Rodents and new Ruminants from the Siwaliks. Pt. 4; Siwalik Birds. Pt. 5; Mastodon Teeth from Perim Island. Pt. 6; Siwalik and Nar- bada Chelonia. Pt. 7; Siwalik Crocodilia, Lacertilia and Ophidia, Pt. 8; Tertiary Fishes. Vou, IV, pt. 1 (1886). Siwalik Mammalia (Supplement 1), pp. 18, pls. 6. ; VoL. IV; pt. 2 O58 yee ies of . Karnul caves : and addendum to pt. 1; pp. 49 » pls vii—xi Vou. IV, pt. 3, 1887. i) Eocene Chenolia from the Salt-range; pp. 7 (59—65), pls. 2 (xii— xili (Ser, VII, XIV.)—TERTIARY AND UPPER CRETACEOUS FAUNA OF WESTERN INDIA, 0 eae DUNCAN and W. PERCY SLADEN, except Pt. 1, by Vou. I, pp. 164+110+382+91—599, pls. 54-28+58+13=104. 1871—85. Pt. 1: Tertiary Crabs from Sind and Kach. Pt. 1 (new 2): Sind Fossil Corals and Alcyonaria; by P. Martin Duncan. Pt. 3: The Fossil Echinoidea o% Sind : Fas 1, The Cardita beaumonti beds; Fas. 2, The Ranikot Serie in Western Sind; Has. 3, ‘(he Khirthar Series; Vas. 4, The Nari (Oligocene) Series ; Fas 5, The Gaj (Miocene) Series; Mas. 6, The Makran (Pliocene) Series ; by Duncan and Sladen. Pt. 4: The Fossil Kchinoidea of Kach and Kattywar; by Duncan, Sladen and Blanford, (Ser. XIII.)—SALT-RANGE FOSSILS, by WILLIAM WAAGEN, Pu.D. Productus-Limestone Group : Vot. I, pt. 1 (1879). Pisces, Cephalopoda, pp. 72, pls. 6. cy “F “ », 2 (1880). Gastropoda and supplement to pt. 1, = 111 (73—183), pls. 10 (1 double), (vii— Xvi). - - re », 3 (1881). Pelecypoda, pp. 144 (185—328), pls. 8 (xvii—xxiv). 5 + 5 », 4 (1882—85). Brachiopoda, pp. 442 (329—770), pls. 62 (xxv—lxxxvi). - ~ >» 3» 5 (1885). Bryozoa—Annelide—EKchinodermata, pp. 64 (771—834), pls. 10 (Ixxxvii—xcvi). ie 55 ri 6 (1886). Coelenterata, pp. 90 (835-924), pls. 20 (xcevii—cxvi). Ris a oa 7 (1887). Coelenterata, Protozoa, pp. 74 (926— 908), pls. 12 (cxvii—cxxviii). Fossils ry the Ceratite Formation : Vol. II, pt. i (1885). Piscus—Ammonoidea, pp. 324, pls. Gana Re&ults : Vol. IV, pt. B (1889), pp. 1—88, pls. 4. ” ” ” ” 2 (18 91), p pp. 89—242, pls. 8. (Ser. XV.)—HIMALAYAN FOSSILS, Upper-triassic and liassic faune of the exotic blocks of Malla Johar in the Bhot Mahals of Kumaon : Vol. I, pt. I (1808), by Dr. C. Diener, pp. 100, pls. 16 (1 double). pulitaodlithic Fossils of Kashmir and Spiti : Vol. I, ‘vt. 2 (1899), by Dr. C. Diener, pp. 96, pls. 8. The Permocarboniferous Fauna of Chitichun No. I: Vol. I, pt. 3 (1897), by Dr. C. Diener, pp. 105, pls. 13 5 The Permian Fossils of the Bp Shales of Kumaon and Garhwal : Vol. I, pt. 4 (1897), y Dr. C. Diener, pp. 54, pls. 5. b> The Permian Fossils of the Central Himalayas: Vol. I, pt. 5 (1903), by Dr. C. Diener, pp. 204, pls. 10. ‘ The Cephalopoda of the Lower Trias: Vol. II, pt. 1 (1897), by Dr. C. Diener, pp. 182, pls. 23. ; The Copbelcred= of the Muschelkalk : Vol. II, pt. 2 (1895), by Dr. C. Diener, pp. 118, pls. 31. Upper Triassic Cephalopoda Faunz of the Himalaya: Vol. III, pt. 1 (1899), by Dr. E. von Mojsisovics, pp. 157, pls. 22. t Trias Brachiopoda and Lamellibranchiata : Vol. III, pt. 2 (1899), by Alexander Bittner, pp. 76, pls. 12 (2 double). : The Fauna of the Spiti Shales: Vol. IV, pt. 1 (1903), by Dr. V. Uhlig, pp. 132, pls. 18. The Fauna of the Tropites-Limestone of Byans: Vol. V, Memoir No. 1 (1906), by Dr. C. Diener, pp. 201, pls. 17 (1 double). ; The Fauna of the Himalayan Muschelkalk: Vol. V, Memoir No. 2 (1907), by Dr. C. Diener, pp. 140, pls. 17 (2 double). 5 Ladinic, Carnic and Noric faune of Spiti : Vol. V, Memoir No. 3 (1908), by Dr. C. Diener, . pp- 157, pls. 24 (3 double). The Cambrian Fossils of Spiti : Vol. V, Memoir No. 4 (in the Press), by F. R. C. Reed. Lower triassic Cephalopoda from Spiti, Malla Johar and Byans: Vol. VI, Memoir No. 1 (in the Press), by Drs. A. von Krafft and C. Diener. The Fauna of the Traumatocrinus Limestone of Painkhanda: Vol. VI, Memoir No. 2 (in the Press), by Dr. C. Diener. (Ser. XVI.)—BALUCHISTAN FOSSILS, by FRITZ NOETLING, Pu.D., F.G.S. The Fauna of the Kellaways of Mazar Drik: Vol. I, pt. 1 (1895), pp. 22, pls. 13. The Fauna of the (Neocomian) Belemnite Beds : Vol. I, pt. 2 (1897), pp»6, pls. 2. The Fauna of the Upper Cretaceous (Maéstrichtien) Beds of the Mari Hills: Vol. I, pt 3 (1897), pp. 79, pls. 23. (NEW SERIES.) The Cambrian Fauna of the Eastern Salt-range: Vol. I, Memoir 1 (1899), K. Redlich, pp. 14, pl. 1. Notes on ee Movpkoey of the Pelecypoda: Vol. I, Memoir 2 (1899), Fritz Noetling, pp. 58, pls. 4. Bauns of ais Miocene Beds of Burma: Vol. I, Memoir 3 (1901), Fritz Noetling, pp. 378, pls. 25. Observations sur ee Plantes Fossiles des Lower Gondwanas: Vol. II, Memoir 1 (1902), R. Zeiller, pp. 39, pls. 7. Permo-Carboniferous (Lower Gondwana) Plants and Vertebrates from Kashmir: (1) Plants, by A. C. Seward; (2} Fishes and Labyrinthodonts, by A. Smith Woodward : Vol. II, Memoir No. 2 (1905), pp. 13, pls. 3. The Lower Palzozoic Fossils of the Northern Shan States, Upper Burma : Vol. II, Memoir No. 3 (1906), by F. R. C. Reed, pp. 154, pls. 8. The Fauna of the Napeng Beds cr the Rhetic Beds of Upper Burma: Vol. II, Memoir No. 4 (1998), by Miss M. Healey, pp. 88, pls. 9 The Devonian Faunas of the Northern Shan States: Vol. 11, Memoir No. 5 (1908), by F. R. C. Reed, pp. 183, pls. 20. ft The Mollusca of the Ranikot Series: Vol. III, Memoir No. 1 (in the Press), by M. Cossmann and G. Pissarro. On Some Fish-remains from the Beds at Dongargaon. Central Provinces : Vol. III, Memoi No. 3 (1908), by A. Smith Woodward, pp. 6, pl. 1. mas Ato The price fixed for these publications is four annas ( 4 pence ing] : minimum charge of Re. ta ) per single plate, with a > RECORDS OF THE GEOLOGICAL SURVEY OF INDIA. “Vor. I, 1868. Part 1 (out of print).—Annual report for 1867. Coal-seams of Tawa valley. Coal in -Garrow Hills. Copper in Bundelkhand. Meteorites. f Part 2 (out of print).—Coal-seams of neighbourhood of Chanda. Coal near Nagpur. Geo- logical notes on Surat collectorate. Uephalopodous fauna of South Indian cretaceous deposits. Lead in Raipur district. Coal in Eastern Hemisphere. Meteorites. Part 3 (out of print).—Gastropodous fauna of South Indian cretaceous deposits. Notes on route from Poona to Nagpur vid Ahmednuggur, Jalna, Loonar, Yeotmahal, Mangali, and Hingunghat. Agate-flake in pliocene (7?) deposits of Upper Godavery. Boundary of Vindhyan series in Rajputana. Meteorites. Vou. II, 1869. Part 1 (out of print).—Valley of Poorna river, West Berar. Kuddapah and Kurnool formations. Geological sketch of Shillong plateau. Gold in Singhboom, etc. Wells at Hazareebagh. Meteorites. ; : Part 2.—Annual report for 1868. Pangshura tecta and other species of Chelonia from newer tertiary deposits of Nerbudda valley. Metamorphic rocks of Bengal. ; so of Kuch, Western India. Geology and physical geography of Nicobar slands. Part 4.—Beds containing silicified wood in Eastern Prome, British Burma. Mineralogical statistics of Kumaon division. Coal-field near Chanda. Lead in Raipur district. Meteorites. Vou. III, 1870. - Part 1.—Annual report for 1869. Geology of neighbourhood of Madras. Alluvial deposits of Irrawadi, contrasted with those of Ganges. Part 2 (out of print).—Geology of Gwalior and vicinity. Slates at Chiteli, Kumaon. Lead vein near Chicholi, Raipur district. Wardha river coal-fields, Berar and Cen- tral Provinces. Coal at Karba in Bilaspur district. Part 3 (out of print)—Mohpani coal-field. Lead-ore at Slimanabad, Jabalpur district. Coal east of Chhatisgarh between Bilaspur and Ranchi. Petroleum in Burma. Petro- leum locality of Sudkal, near Futtijung, west of Rawalpindi. Argentiferous galena and copper in Manbhum. Assays of iron ores. Part z Nest of print).—Geology of Mount ‘illa, Punjab. Copper deposits of Dalbhum and Singbhum : 1.—Copper mines of Singbhum : 2.—Copper of Dalbhum and Sing- bhum. Meteorites. Vou. IV, 1871. Part 1.—Annual report for 1870. Alleged discovery of coal near Gooty, and of indications of coal in Cuddapah district. Mineral statistics of Kumaon division. Part 2.—Axial group in Western Prome. Geological structure of Southern Konkan. Supposed occurrence of native antimony in the Straits Settlements. Deposit.in boilers of steam-engines at Raniganj. Plant-bearing sandstones of Godavari valley, on south- ern extensions of Kamthi group to neighbourhood of Ellore and Rajamandri, and on possible occurrence of coal in same direction. Part 3.—Borings for coal in Godavari valley near Dumagudem and Bhadrachalam. Narbada coal-basin. Geology of Central Provinces. Plant-bearing sandstones of Godavari valley. Part 4.—Ammonite fauna of Kutch. Haigur and Hengir (Gangpur) Coal-field. Sandstone = neighbourhood of first barrier on Godavari, and in ee between Godavari Be ore. Vou. V, 1872. Part 1.—Annual report for 1871. Relations of rocks near Murree (Mari), Punjab. Mineral- ogical notes on gneiss of South Mirzapur and adjoining country. Sandstones in Siegert of first barrier on Godavari, and in country between Godavari and re. 7 Part 2.—Coasts of Baluchistan and Persia from Karachi to head of Persian Gulf, and some of Gulf Islands. Parts of Kummummet and Hanamconda districts in Nizam’s Dominions. Geology of Orissa. New coal-field in south-eastern Hyderabad (Deccan) territory. Part 3.—Maskat and Massandim on east coast of Arabia. Example of local jointing, Axial group of Western Prome. Geology of Bombay Presidency. Part 4.—Coal in northern region of Satpura basin. Evidence afforded by raised oyster banks on coasts of India, in estimating amount of elevation indicated thereby. Possible field of coal-measures in Godavari district, Madras Presidency. Lameta or intra-trappean formation of Central India. Petroleum localities in Pegu. Supposed eozoonal limestone of Yellam Bile. ; Vo. VI, 1873. Part 1.—Annual report for 1872. Geology of North-West Provinces. Part 2.—Bisrampur coal-field. Mineralogical notes on gneiss of South Mirzapur and ad- joining country. Part 3.—Celt in ossiferous deposits of Narbada valley (Pliocene of Falconer) : on age of deposits, and on associated shells. Barakars (coal-measures) in Beddadanole field, pee district. Geology of parts of Upper Punjab. Coal in India. Salt-springs of Pegu. Part 4.—Iron deposits of Chanda (Central Provinces). Barren Islands and Narkondam. Metalliferous resources of British Burma. Vou. VII, 1874. Part 1 (out of print).—Annual report for 1873. Hill ranges between Indus valley in Ladak and Shah-i-Dula on frontier of Yarkand territory. Iron ores of Kumaon. Raw materials for iron-smelting in Raniganj field. -Elastic sandstone, or so-called Itaco- lumyte. Geological notes on part of Northern Hazaribagh. Part 2 (out of print).—Geological notes on route traversed by Yarkand Embassy from Shah-i-Dula to Yarkand and Kashgar. Jade in Karakas valley, ‘'urkistan. Notes from Eastern Himalaya. Petroleum in Assam. Coal in Garo Hills. Copper in Narbada valley. Potash-sa)+; from East India. Geology of neighbourhood of Mari hill station in Punjab. Part 3.—Geological observations made on a visit to Chaderkul, Thian Shan range. Former extensior of glaciers within Kangra district. Building and ornamental stones of India. Materials for iron manufacture in Raniganj coal-field. Manganese-ore in Wardha coal-field. Part 4 (out of print).—Auriferous rocks of Dhambal hills, Dharwar district. Antiquity of human race in India. Coal recently discovered in the country of Luni Pathans, south-east corner of Afghanistan. Progress of peclogieat investigation in Godavari district, Madras Presidency. Subsidiary materials for artificial fuel. Vor. VIII, 1875. . Part 1.—Annual report for 1874. The Altum-Artush considered from geological point of view. Evidences of ‘ ground-ice’ in tropical India, during Talchir period. Trials of Raniganj fire-bricks. Part 2 (out of print).—Gold-fields of south-east Wynaad, Madras Presidency. Geological notes on Khareean hills in Upper Punjab. Water-becring strata of Surat district. Geology of Scindia’s territories. Part 3 (out of print).—Shahpur coal-field, with notice of coal explorations in Narbada region. Coal recently found near Mofiong, Khasia Hills. 2 Part 4 {out of print).—Geology of Nepal. Raigarh and Hingir coal-fields. Vor. IX, 1876. Part 1 (out of print).—Annual report for 1875. Geology of Sind. Part 2.—Retirement of Dr. Oldham. Age of some fossil floras in India. Cranium of Stegodon Ganesa, with notes on sub-genus and allied forms. Sub-Himalayan series in Jamu (Jammoo) Hills. : Part 3.—Fossil floras in India. Geological age of certain groups comprised in Gondwana series of India, and on evidence they afford of distinct zoological and botanical terres- trial regions in ancient epochs. Relations of fossiliferous strata at Maleri and Kota, near Sironcha, C. P. Fossil mammalian faune of India and Burma. Part 4.—Yossil floras in India. Osteology of Merycopotamus dissimilis. Addenda and: Corrigenda to paper on tertiary mammalia. Plesiosaurus in India. Geology of Pir Panjal and neighbouring districts. 8 Vor. X, 1877. Part 1.—Annual report for 1876. Geological notes on Great Indian Desert between Sind and Rajputana. Cretaceous genus Omphalia near Nameho lake, Tibet, about 75 miles north of Lhassa. Estheria in Gondwana formation. Vertebrata from Indian tertiary and secondary rocks. New Emydine from the upper tertiaries of Northern Punjab. Observations on under-ground temperature. ’ Part 2.—Rocks of the Lower Godavari. ‘Atgarh Sandstones’ near Cuttack. Fossil floras _ in India. New or rare mammals from the Siwaliks. Arvali series in North-eastern Rajputana. Borings for coal in India. Geology of India. Part $.—Tertiary zone and underlying rocks in North-west Punjab. Fossil floras in India. Erratics in Potwar. Coal explorations in Darjiling district. Limestones in neighbour- hood of Barakar. Forms of blowing-machine used by smiths of Upper Assam. Analyses of Raniganj coals. Part 4.—Geology of Mahanadi basin and its vicinity. Diamonds, gold, and lead ores of Sambalpur district. ‘Eryon Comp. Barrovensis,’ McCoy, from Sripermatur group near Madras. Fossil floras in India. The Blaini group and ‘Central Gneiss’ in Simla Himalayas. Tertiaries of North-West Punjab. Genera Cheromeryx und Rhagatherium. : Vou. XI, 1878. Part 1.—Annual report for 1877. Geology of Upper Godavari basin, between_river Wardha and Godavari, near Sironcha. Geology of Kashmir, Kishtwar, and Pangi. ges mammals. Palzontological relations of Gondwana system. ‘Erratics im unjab.’ Part 2.—Geology of Sind (second notice). Origin of Kumaun lakes. Trip over Milam Pass, Kumaun. Mud volcanoes of Ramri and Cheduba. Mineral resources of Ramri, Cheduba and adjacent islands. Part $.—Gold industry in Wynaad. Upper Gondwana series in Trichinopoly and Nellore- Kistna districts. Senarmontite from Sarawak. Part 4.—Geographical distribution of fossil organisms in India. Submerged forest on Bombay Island. Vou. XII, 1879. Part 1.—Annual report for 1878. Geology of Kashmir (third notice). Siwalik mammalia. _ Siwalik birds. Tour through Hangrang and Spiti. Mud eruption in Ramri Island (Arakan). Braunite, with Rhodonite, from Nagpur, Central Provinces. cal notes from Satpura coal-basin. Coal importations into India. Part 2.—Mohpani coal-field. Pyrolnsite with Psilomelane at Gosalpur, Jabalpur district. Geological reconnaissance from Indus at Kushalgarh to Kurram at Thal on Afghan frontier. Geology of Upper Punjab. Part $.—Geological features of northern Madura, Pudukota State, and southern parts of Tanjore and Trichinopoly districts included within limits of sheet 80 of Indian Atlas. Cretaceous fossils from Trichinopoly district, collected in 1877-78. Sphenophyllum and other Equisetacee with reference to Indian form Trizygia Speciosa, Royle (Spheno- phyllum Trizygia, Ung.). Mysorin and Atacamite from Nellore district. Corundum from Khasi Hills. Joga neighbourhood and old mines on Nerbudda. Part 4.—‘ Attock Slates’ and their probable geological position. Marginal bone of unde- scribed tortoise, from Upper Siwaliks, near Nila, in Potwar, Punjab. Geology of North Arcot district. Road section from Murree to Abbottabad. Palzontologi- Vor. XIII, 1880. Part 1.—Annual report for 1879. Geology of Upper Godavari basin in neighb Sironcha. Geology of Ladak and neighbouring districts. Teeth of foseil age Ramri Island and Punjab. Fossil genera Néggerathia, Sthg., Noéggerathiopsis, Fstm. and ee ee Lear = Bevo A ark secondary rocks of Europe, Asia, and ralia. Foss: ants from Ka h i irguj i i 3 ota zal pl = ywar, Shekh Budin, and Sirgujah. Volanic foci art 2.—Geological notes. Palzontological notes on lower trias of Himal i ’ wells at Pondicherry, and possibility of finding sources of akan ores ue Part 3.—Kumaun lakes. Celt of palzolithic type in Punjab. Palxontological notes from Karharbari and South Rewa coal-fields. Correlation of Gondwana flora with other floras. Artesian wells at Pondicherry. Salt in Rajputana. Gas and mud eruption on Arakan coast on 12th March 1879 and in June 1843. P 9 Part 4.—Pleistocene deposits of Northern Punjab, and evidence they afford of extreme climate during portion of that period. Useful minerals of Arvali region. Correlation of Gondwana flora with that of Australian coal-bearing system. Reh or alkali soils and ae well waters. Reh soils of Upper India. Naini Tal landslip, 18th Septem- ber 1880. Vou. XIV, 1881. Part 1.—Annual report for 1880. Geology of part of Dardistan, Baltistan, and neighbour- ing districts. Siwalik carnivora. Siwalik group of Sub-Himalayan region. South Rewah Gondwana basin. Ferruginous beds associated with basaltic rocks of north- eastern Ulster, in relation to Indian laterite. Rajmahal plants. Travelled blocks of the Punjab. Appendix to ‘ Palzontological notes on lower trias of Himalayas.’ Mam- malian fossils from Perim Island. m Part 2.—Nahan-Siwalik unconformity in North-Western Himalaya. Gondwana verte- brates. Ossiferous beds of Hundes in Tibet. Mining records and mining record office of Great Britain; and Coal and Metalliferous Mines Act of 1872 (England). Cobaltite and danaite from Khetri mines, Rajputana; with remarks on Jaipurite (Syepoorite). Zinc-ore (Smithsonite and Blende) with barytes in Karnul district, Madras. Mud eruption in island of Cheduba. Part 3.—Artesian borings in India. Oligoclase granite at Wangtu on Sutlej, North-West Himalayas. Fish-palate from Siwaliks. Paleontological notes from Hazaribagh and Lohardagga districts. Fossil carnivora from Siwalik hills. Part 4.—Unification of geological nomenclature and cartography. Geology of Arvali region, central and eastern. Native antimony obtained at Pulo Obin, near Singapore. Tur- gite from Juggiapett, Kistnah district; and zinc carbonate from Karnul, Madras. Section from Dalhousie to Pangi, vid Sach Pass. South Rewah Gondwana basin. Submerged forest on Bombay Island. Vou. XV, 1882. Part 1.—Annual report for 1881. Geology of North-West Kashmir and Khagan. Gend- wana labyrinthodonts. Siwalik and Jamna mammals. Geology of Dalhousie, North- West Himalaya. Palm leaves from (tertiary) Murree and Kasauli beds in India. Iridosmine from Noa-Dihing river, Upper Assam, and Platinum from Chutia Nagpur. On (1) copper mine near Yongri hill, Darjiling district; (2) arsenical pyrites in same neighbourhood; (3) kaolin at Darjiling. Analyses of coal and fire-clay from Makum coal-field, Upper Assam. Experiments on coal of Pind Dadun Khan, Salt-range, with reference to production of gas, made April 29th, 1881. Proceedings of International Congress of Bologna. Part 2.—Geology of Travancore State. Warkilli beds and reported associated deposits at Quilon, in Travancore. Siwalik and Narbada fossils. Coal-bearing rocks of Upper Rer and Mand rivers in Western Chutia Nagpur. Pench river coal-field in Chhind- wara district, Central Provinces. Bovings for coal at Engsein, British Burma. Sap- phires in North-Western Himalaya. Eruption of mud volcanoes in Cheduba. Part 3.—Coal of Mach (Much) in Bolan Pass, and of Sharigh on Harnai route between Sibi and Quetta. Crystals of stilbite from Western Ghats, Bombay. Traps of Darang and Mandi in North-Western Himalayas. Connexion between Hazara and Kashmir series. Umaria coal-field (South Rewah Gondwana basin). Daranggiri coal-field, Garo Hills, Assam. Coal in Myanoung division, Henzada district. Part 4 (out of print).—Gold-fields of Mysore. SBorings for coal at Beddadanol, Godavari district, in 1874. Supposed occurrence of coal on Kistna. Vou. XVI, 1883. Part 7.—Annual report for 1882. Richthofenia, Kays (Anomia Lawrenciana, Koninck). Geology of South Travancore. Geology of Chamba. Basalts of Bombay. Part 2.—Synopsis of fossil vertebrata of India. Bijori Labyrinthodont. Skuli of Hippo. therium antilopinum. Iron ores, and subsidiary materials for manufacture of iron, in north-eastern part of Jabalpur district. Laterite and other manganese-ore occurring at Gosulpore, Jabalpur district. Umaria coal-field. Part 3.—Microscopic structure of some Dalhousie rocks. Lavas of Aden. Probable occur- rence of Siwalik strata in China and Japan. Mastodon angustidens in India. Traverse between Almora and Mussooree. Cretaceous coal-measures at Borsora, in Khasia Hills, near Laour, in Sylhet. 10 Part 4.—Palzontological notes from Daltonganj and Hutar coal-fields in Chota Nagpur. Altered basalts of Dalhousie region in North-Western Himalayas. Microscopic struc- ture of some Sub-Himalayan rocks of tertiary age. Geology of Jaunsar and Lower Himalayas. Traverse through Eastern Khasia, Jaintia, and North Cachar Hills. Native lead from Maulmain and chromite from the Andaman Islands. Fiery eruption from one of mud volcanoes of Cheduba Island, Arakan. Irrigation from wells in North-Western Provinces and Oudh. Vor. XVII, 1884. Part 1.—Annual report for 1883. Smooth-water anchorages or mud-banks of Narrakal and eppy on Travancore coast. Billa Surgam and other caves in Kurnool district. Geology of Chuari and Sihunta parganas of Chamba. Lyttonia, Waagen, in Kuling series of Kashmir. Part 2.—Karthquake of 31st December 1881 Microscopic structure of some Himalayan granites and gneissose granites. Choi coal exploration. Re-discovery of fossils in Siwalik beds. Mineral resources of the Andaman Islands in neighbourhood of Port Blair. Intertrappean beds in Deccan and Laramie group in Western North America. Part 3 (out of print).—Microscopic structure of some Arvali rocks. Section along Indus from Peshawar Valley to Salt-range. Sites for boring in Raigarh-Hingir coal-field (first notice). Lignite near Raipore, Central Provinces. Turquoise mines of Nishapir, Khorassan. Fiery eruption from Minbyin mud volcano of Cheduba Island, Arakan. Langrin coal-field, South-Western Khasia Hills. Umaria coal-field. Part 4.—Geology of part of Gangasulan pargana of British Garhwal. Slates and schists imbedded in gneissose granite of North-West Himalayas. Geology of Takht-i-Sulei- man. Smooth-water anchorages of Travancore coast. Auriferous sands of the Suban- siri river. Pondicherry lignite, and phosphatic rocks at Musuri. Billa Surgam caves. Vou. XVIII, 1885. Part 1.—Annual report for 1884. Country between Singareni coal-field and Kistna river. Geological sketch of country between Singareni coal-field and Hyderabad. Coal and limestone in Doigrung river near Golaghat, Assam. Homotaxis, as illustrated from Indian formations. Afghan field notes. Part 2.—Fossiliferous series in Lower Himalaya, Garhwal. Age of Mandhali series in Lower Himalaya. Siwalik camel (Camelus Antiquus, nobis ex Falc. and Caut. MS.). Geology of Chamba. Probability of obtaining water by means of artesian wells in plains of Upper India. Artesian sources in plains of Upper India. Geology of Aka Hills. Alleged tendency of Arakan mud volcanoes to burst into eruption most frequently during rains. Analyses of phosphatic nodules and rock from Mussooree. Part 3.—Geology of Andaman Islands. Third species of Merycopotamus. Percolation as affected by current. Pirthalla and Chandpur meteorites. Oil-wells and coal in Thayetmyo district, British Burma. Antimony deposits in Maulman district. Kash- mir earthquake of 30th May 1885. Bengal earthquake of 14th July 1885. Part 4.—Geological work in Chhattisgarh division of Central Provinces. Bengal earth- quake of 14th July 1885. Kashmir earthquake of 30th May 1885. Excavations in Billa Surgam caves. Nepaulite. Sabetmahet meteorite. Vou. XIX, 1886. Part 1.—Annual report for 1885. International Geological Congress of Berlin. Paleozoic Fossils in Olive group of Salt-range. Correlation of Indian and Australian coal- bearing beds. Afghan and Persian Field-notes. Section from Simla to Wangtu, and petrological character of Amphibolites and Quartz Diorites of Sutlej valley. Part 2.—Geology of parts of Bellary and Anantapur districts. Geology of Upper Dehing basin in Singpho Hills. Microscopic characters of eruntive rorks from Central Hima- layas. Mammalia of Karnul Caves. Prospects of finding coal in Western Rajputana. Olive group of Salt-range. Boulder-beds of Salt-range. Gondwana Homotaxis. Part $.—Geological sketch of Vizagapatam district. Madras. Geology of Northern Jesal- mer. Microscopic structure of Malaini rocks of Arvali region. Malanjkhandi copper- ore in Balaghat district, C. P. _ , Part 4.—Petroleum in India. Petroleum exploration at Khitan. Boring in Chhattisgarh coal-fields. Field-notes from Afghanistan: No, 3, Turkistan. Fiery eruption from one of mud volcanoes of Cheduba Island, Arakan. Nammianthal aerolite. Analysis of gold dust from Meza valley, Upper Burma. u Vou. XX, 1887. Part 1.—Annual report for 1886. Field-notes from Afghanistan: No. 4, from Turkistan to India. Physical geology of West British Garhwal; with notes on a route traversed through Jaunsar-Bawar and Tiri-Garhwal. Geology of Garo Hills. Indian image- stones. Soundings recently taken off Barren Island and Narcondam. Talchir boulder- beds. Analysis of khosphatic Nodules from Salt-range, Punjab. Part 2.—Fossil vertebrata of India. Echinoidea of cretaceous series of Lower Narbada Valley. Field-notes : No. 5—to accompany geological sketch map of Afghanistan and North-Eastern Khorassan. Microscopic structure of Rajmahal and Deccan traps. Dolerite of Chor. Identity of Olive series in east with speckled sandstone in west of Salt-range in Punjab. . Part 3.—Retirement of Mr. Medlicott. J. B. Mushketoff’s Geology of Russian Turkistan. Crystalline and metamorphic rocks of Lower Himalaya, Garhwal, and Kumaun, Sec- tion I. Geology of Simla and Jutogh. ‘ Lalitpur ’ meteorite. Part _4.—Points in Himalayan geology. Crystalline and metamorphic rocks of Lower Himalaya, Garhwal, and Kumaun, Section II. Iron industry of western portion of Raipur. Notes on Upper Burma. Boring exploration in Chhattisgarh coal-fields. (Second notice). Pressure Metamorphism, with reference to foliation of Himalayan Gneissose Granite. Papers on Himalayan Geology and Microscopic Petrology. Vor. XXI, 1888. Part 1.—Annual report for 1887. Crystalline and metamorphic rocks of Lower Himalaya, Garhwal, and Kumaun, Section III. Birds’-nest of Elephant Island, Mergui Archi- pelago. Exploration of Jessalmer, with a view to discovery of coal. Facetted pebble from boulder bed (‘speckled sandstone’) of Mount Chel in Salt-range, Punjab. Nodular stones obtained off Colombo. Part 2.—Award of Wollaston Gold Medal, Geological Society of London, 1888. Dharwar System in South India. Igneous rocks of Raipur and Balaghat, Central Provinces. Sangar Marg and Mehowgale coal-fields, Kashmir. ‘ Part 3.—Manganese Iron and Manganese Ores of Jabalpur. ‘ The Carboniferous Glacial Period.’ Pre-tertiary sedimentary formations of Simla region of Lower Himalayas. Part 4.—Indian fossil vertebrates. Geology of North-West Himalayas. Blown-sand rock sculpture. Nummulites in Zanskar. Mica traps from Barakar and Raniganj- Vout. XXII, 1889. Part 1.—Annual report for 1888. Dharwar System in South India. Wajra Karur diamonds, and M. Chaper’s alleged discovery of diamonds in pegmatite. Generic posi- tion of so-called Plesiosaurus Indicus. Flexible sandstone or Itacolumite, its nature, mode of occurrence in India, and cause of its flexibility. Siwalik and Narbada Chelonia. Part 2.Indian Steatite. Distorted pebbles in Siwalik conglomerate. ‘ Carboniferous Glacial Period.’ Oil-fields of Twingoung and Beme, Burma. Gypsum of Nehal Nadi, Kumaun. Materials for pottery in neighbourhood of Jabalpur and Umaria. Part 3.—Coal outcrops in Sharigh Valley, Baluchistan. Trilobites in Neobolus beds of Salt-range. Geological notes. Cherra Poonjee coal-field, in Khasia Hills. Cobalti- ferous Matt from Nepal. President of Geological Society of London on International Geological Congress of 1888. Tin-mining in Mergui district. Part 4.—Wand-tortoises of Siwaliks. Pelvis of a ruminant from Siwaliks. Assays from Sambhar Salt-Lake in Rajputana. Manganiferous iron and Manganese Ores of Jabal- pur. Palagonite-bearing traps of Rajmahal hills and Deccan. Tin-smelting in Mala Peninsula. Provisional Index of Local Distribution of Important Minerals, Miscel- laneous Minerals, Gem Stones and Quarry Stones in Indian Empire. Part 1. Vor. XXIII, 1890. Part 1.—Annual report for 1889. Lakadong coal-fields, Jaintia Hills. Pectoral and pelvic girdles and skull of Indian Dicynodonts. Vertebrate remains from Nagpur district (with description of fish-skull). Crystalline and metamorphic rocks of Lower Hima- layas, Garhwdl and Kumaun, Section IV. Vivalves of Olive-group, Salt-range. Mud-banks of Travancore coasts. Part 2.—Petroleum explorations in Harnai district, Baluchistan. Sapphire Mines of Kashmir. Supposed Matrix of Diamond at Wajra Karur, Madras. Sonapet Gold- field. Field notes from Shan Hills (Upper Baca New species of Syringospheride. 12 Part 3.—Geology and Economic Resources of Country adjoining Sind-Pishin Railway between Sharigh and Spintangi, and of country between it and Khattan. Journey through India in 1888-89, by Dr. Johannes Walther. Coal-fields of Lairungao, Mao- sandram, and Mao-belar-kar, in the Khasi Hills. Indian Steatite. Provisional Index of Local Distribution of Important Minerals, Miscellaneous Minerals, Gem Stones, and Quarry Stones in Indian Empire. sie! Wass Part 4.—Geological sketch of Naini Tal; with remarks on natural conditions governing mountain slopes. Fossil Indian Bird Bones. Darjiling Coal between Lisu and Ramthi rivers. Basic Eruptive Rocks of Kadapah Area. Deep Boring at Lucknow. Coal Seam of Dore Ravine, Hazara. Vor. XXIV, 189%. Part 1.—Annual report for 1890. Geology of Salt-range of Punjab, with re-considered theory of Origin and Age of Salt-Mart. Graphite in decomposed Gneiss (Laterite) in Ceylon. Glaciers of Kabru, Pandim, etc. Salts of Sambhar Lake in Rajputana, and ‘Reh’ from Aligarh in North-Western Provinces. Analysis of Dolomite from Salt- range, Punjab. Part 2.—Oil near Moghal Kot, in Sherdni country, Suleiman Hills. Mineral Oil from Suleiman Hills. Geology of Lushai Hills. Coal-fields in Northern Shan States. Reported Namséka Ruby-mine in Mainglén State. Tourmaline (Schorl) Mines in Mainglén State. Salt-spring near Bawgyo, Thibaw State. Part 3.—Boring in Daltongunj Coal-field, Palamow. Death of Dr. P. Martin Duncan. Pyroxenic varieties of Gneiss and Scapolite-bearing Rocks. Part 4.—Mammalian Bones from Mongolia. Darjiling Coal Exploration. Geology and Mineral Resources of Sikkim. Rocks from the Salt-range, Punjab. Vou. XXV, 1892. Part 1.—Annual report for 1891. Geology of Thal Chotiali and part of Mari country. Petrological Notes on Boulder-bed of Salt-range, Punjab. Sub-recent and Recent Deposits of valley plains of Quetta, Pishin, and Dasht-i-Bedaolat; with appendices on Chamans of Quetta; and Artesian water-supply of Quetta and Pishin. Part 2 (out of print).—Geology of Saféd Koh. Jherria Coal-field. Part 3.—Locality of Indian Tscheffkinite. Geological Sketch of country north of Bhamo. Economic resources of Amber and Jade mines area in Upper Burma. lIron-ores and Tron Industries of Salem District. Riebeckite in India. Coal on Great Tenasserim River, Lower Burma. Part 4.—Oil Springs at Moghal Kot in Shirani Hills. Mineral Oil from Suleiman Hills. New Amber-like Resin in Burma. ‘Triassic Deposits of Salt-range. Vor. XXVI, 1893. Part 1.—Annual report for 1892. Central Himalayas. Jadeite in Upper Burma. Bur- mite, new Fossil Resin from Upper Burma. Prospecting Operations, Mergui District, - Part 2.—Earthquake in Baluchistan on 20th December 1892. Burmite, new amber-like pe resin from Upper Burma. Alluvial deposits and Subterranean water-supply of Rangoon. : Part 3.—Geology of Sherani Hills. Carboniferous Fossils from Tenasserim. Boring at Chandernagore. Granite in Tavoy and Mergui. Part 4.—Geology of country between Chappar Rift and Harnai in Baluchistén. Geology of part of Tenasserim Valley with special reference to Tendau-Kamapying Coal-field. Magnetite containing Manganese and Alumina. Hislopite. Vou. XXVII, 1894. fart 1.—Annual report for 1893. Bhaganwala Coal-field, Salt-range, Punjab. Part 2.—Petroleum from Burma. Singareni Coal-field, Hyderabad (Deccan). Gohna Landslip, Garhwal. ; Part 3.—Cambrian Formation of Eastern Salt-range. Giridih (Karharbari) Coal-fields. Chipped (?) Flints in Upper Miocene of Burma. Velates Schmideliana, Chemn., and Provelates grandis, Sow. sp., in Tertiary Formation of India and Burma. | Part 4.—Geology of Wuntho in Upper Burma. Echinoids from Upper Cretaceous System of Baluchistan. Highly Phosphatic Mica Peridotites intrusive in Lower Gondwana Rocks of Bengal. Mica-Hypersthene-Hornblende-Peridotite in Bengal. Vou. XXVIII, 1895. Part 1.—Annual report for 1894. Cretaceous Formation of Pondicherry. Early allusion to Barren Island. Bibliography of Barren Island and Narcondam from 1884 to 1894. 13 Part 2.—Cretaceous Rocks of Southern India and geographical conditions during later cretaceous times. Experimental Boring for Petroleum at Sukkur from October 1893 to March 1895. Tertiary system in Burma. Part 3.—Jadeite and other rocks, from Tammaw in Upper Burma. Geology of Tochi Valley. Lower Gondwanas in Argentina. Part 4.—Igneous Rocks of Giridih (Kurhurbaree) Coal-field and their Contact Effects. Vindhyan system south of Sone and their relation to so-called Lower Vindhyans. Lower Vindhyan area of Sone Valley. Tertiary system in Burma. Vou. XXIX, 1896. Part 1.—Annual report for 1895. Acicular inclusions in Indian Garnets. Origin and Growth of Garnets and of their Micropegmatitic intergrowths in Pyroxenic rocks. Part 2.—Ultra-basic rocks and deiived minerals of Chalk (Magnesite) hills, and other localities near Salem, Madras. Corundum localities in Salem and Coimbatore districts, Madras. Corundum and Kyanite in Manbhum district, Bengal. Ancient Geography of ‘‘Gondwanaland.’’ Notes. Part 3.—Igneous Rocks from the Tochi Valley. Notes. Part 4.—Steatite mines, Minbu district, Burma. Lower Vindhyan (Sub-Kaimur) area of Sone Valley, Rewah. Notes. Vou. XXX, 1897. Part 1.—Annual report for 1896. Norite and associated Basic Dykes and Lava-flows in Southern India. Genus Vertebraria. On-~Glossopteris and Vertebraria. Part 2.—Cretaceous Deposits of Pondicherri. Notes. Part 3.—Flow structure in igneous dyke. Olivine-norite dykes at Coonoor. Excavations. for corundum near Palakod, Salem District. Occurrence of coal at Palana in Bikanir. Geological specimens collected by Afghan-Baluch Boundary Commission of 1896. Part 4.—Nemalite from Afghanistan. Quartz-barytes rock in Salem District, Madras Presidency. Worn femur of Hippopotamus irravadicus, Caut. and Falc., from Lower Pliocene of Burma. Supposed coal at Jaintia, Baxa Duars. Percussion Figures on micas. Notes. Vou. XXXI, 1904. Part 1 (out of print).—Prefatory Notice. Copper-ore near Komai, Darjeeling district. Zewan beds in Vihi district, Kashmir. Coal deposits of Isa Khel, Mianwali district, Punjab. Um-Rileng coal-beds, Assam. Sapphirine-bearing rock from Vizagapatam . district. Miscellaneous Notes. Assays. Part 2 (out of print).—Lt.-Genl. C. A. McMahon. Cyclobus Haydeni Diener. Auriferous- Occurrences of Chota Nagpur, Bengal. On the feasibility of introducing modern methods of Coke-making at East Indian Railway Collieries, with supplementary note by Director, Geological Survey of India. Miscellaneous Notes. Part 3 (out of print).—Upper Paleozoic formations of Eurasia. Glaciation and History of Sind Valley. Halorites in Trias of Baluchistan. Geology and Mineral Resources of Mayurbhanj. Miscellaneous Notes. : Part 4 (out of print).—Geology of Upper Assam. Auriferous Occurrences of Assam. Curious occurrence of Scapolite from Madras Presidency. Miscellaneous Notes. Index. Vor. XXXII, 1905. Part 1 (out of print).—Review of Mineral Production of India during 1898—1903. Part 2 (out of print).—General report, April 1903 to December 1904. Geoiogy of Pro- vinces of Tsang and U in Tibet. Bauxite in India. Miscellaneous Notes. Part 3 (out of print).—Anthracolithic Fauna from Subansri Gorge, Assam. Elephas- Antiquus (Namadicus) in Godavari Alluvium. Triassic Fauna of Tropites-Limestone of Byans. Amblygonite in Kashmir. Miscellaneous Notes. Part j.—Obituary notices of H. B. Medlicott and W. T. Blanford. Kangra Earthquake of 4th April 1905. Index to Volume XXXII. Vou. XXXIII, 1906. os Part 1 (out of print).—Mineral Production of India during 1904. Pleistocene Movement in Indian Peninsula. Recent Changes in Course of Nam-tu River, Northern Shan States. Natural Bridge in Gokteik Gorge. Geology and Mineral Resources of Narnaul Dis-. trict (Patiala State). Miscellaneous Notes. ‘ Part 2 (out of print).—General report for 1905. Lashio Coal-field, Northern Shan States. Namma, Mansang and Man-se-le Coal-fields, Northern Shan States,.Burma Mis- cellaneous Notes. 14 ‘ Part $.—Petrology and Manganese-Ore Deposits of Sausar Tahsil, Chhindwara district, Central Provinces. Geology of parts of valley of Kanhan River in Nagpur and Chhindwara districts, Central Provinces. Manganite from Sandur Hills. Miscella- neous Notes. Part 4 (out of print).—Composition and Quality of Indian Coals. Classification of the Vindhyan System. Geology of State of Panna with reference to the Diamond bearing Deposits. Index to Volume XXXIII. Vou. XXXIV, 1906. Part 1.—Fossils from Halorites Limestone of Bambanag Cliff, Kumaon. Upper-Triassic Fauna from Pishin District, Baluchistan. Geology of portion of Bhutan. Coal Occur- rences in Foot-hills of Bhutan. Dandli Coal-field : Coal outcrops in Kotli Tehsil of Jammu State. Miscellaneous Notes. Part 2.—Mineral Production of India during 1905. Nummulites Douvillei, with remarks on Zonal Distribution of Indian Nummulites. Auriferous Tracts in Southern India, Abandonment of Collieries at Warora, Central Provinces. Miscellaneous Notes. __ Part 3.—Explosion Craters in Lower Chindwin district, Burma. Lavas of Pavagad Hill. Gibbsite with Manganese-ore from Talevadi, Belgaum district, and Gibbsite from Bhekowli, Satara District. Classification of Tertiary System in Sind with reference to Zonal distribution of Eocene Echinoidea. Part 4 (out of print).—Jaipur and Nazira Coal-fields, Upper Assam. Makum Coal-field between Tirap and Namdang Streams. Kabat Anticline, near Seiktein, Myingyan district, Upper Burma. Asymmetry of Yenangyat-Singu Anticline, Upper Burma. Northern part of Gwegyo Anticline, Myingyan District, Upper Burma. Breynia Multituberculata, from Nari of Baluchistan and Sind. Index to Volume XXXIV. Vou. XXXV, 1907. Part 1.—General report for 1906. Orthophragmina and Lepidocyclina in Nummulitic sacs Meteoric Shower of 22nd October 1903 at Dokdchi and neighbourhood, Dacca istrict. Part 2.—Indian Aerolites. Brine-wells at Bawgyo, Northern Shan States. Gold-bearing Deposits of Loi Twang, Shan States. Physa Prinsepii in Maestrichtian strata of Baluchistan. Miscellaneous Notes. Part 3.—Preliminary survey of certain Glaciers in North-West Himalaya. A.—Notes on certain Glaciers in North-West Kashmir. Part 4.—Preliminary survey of certain Glaciers in North-West Himalaya. B.—Notes on certain Glaciers in Lahaul. C.—Notes on certain Glaciers in Kumaon. Index to Volume XXXV. f Vor. XXXVI, 1907-08. : Part 1.—Petrological Study of Rocks from hill tracts, Vizagapatam district, Madras Presidency. Nepheline Syenites from hill tracts, Vizagapatam district, Madras Presi- dency. Stratigraphical Position of Gangamopteris Beds of Kashmir. Volcanic out- burst of Late Tertiary Age in South Hsenwi, N. Shan States. New suide from Bugti Hills, Baluchistan. Permo-Carboniferous Plants from Kashmir. Part 2.—Mineral Production of India during 1906. Ammonites of Bagh Beds. Mis- cellaneous Notes. Part 3.—Marine fossils in Yenangyaung oil-field, Upper Burma. Fresh-water shells of genus Batissa in Yenangyaung oil-field, Upper Burma. New Species of Dendrophyllia from Upper Miocene of Burma. Structure and age of Taungtha hills, Myingyan dis- trict, Upper Burma. Fossils from Sedimentary rocks of Oman (Arabia). Rubies in Kachin hills, Upper Burma. Cretaceous Orbitoides of India. Two Calcutta Earth- quakes of 1906. Miscellaneous Notes. Part 4.—Pseudo-Fucoids from Pab sandstones at Fort Munro, and from Vindhyan series. Jadeite in Kachin Hills, Upper Burma. Wetchok-Yedwet Pegu outcrop, Magwe dis- trict, Upper Burma. Group of manganates, comprising Hollandite, Psilomelane and Coronadite. Occurrence of Wolfram in Nagpur district, Central Provinces. Mis- cellaneous Notes. Index to Volume XXXVI. : Vou. XXXVII, 1908-09. Part 1.—General report for 1907. Mineral Production of India during 1907. Striated boulders in the Blaini formation. Part 2.—Tertiary and Post-Tertiary Freshwater Deposits of Baluchistan and Sind. Geo- logy and Minerals of Rajpipla. Suitability of Rajmahal sands for glass-making. Vredenburgite, Sitaparite and Juddite. Laterites from the Central Provinces. Mis- cellaneous notes. The price fixed for these publications is 1 rupee (1s. 4d.) each part or 2 rupegr (23. 8d.) each volume of four parts. 18 PUBLICATIONS. The publications of the Departmert include~— PaLzZonToLocia InpIcA, arranged in series, and sold in parts which are priced at 4 annas (4 pence) per plate. Memorrs, Vols. I—XXXVI, including the larger papers on geological subjects. Recorps, Vols. [—XXXV1, including the shorter papers and Annual Reports from 1868 to 1908, sold in parts, price one rupee each. Manvats, GUIDES AND Maps. A compiete list of the contents of these publications can be obtained by application to the Registrar, Geological Survey of India, 27, Chowringhee Road, Calcutta. Indexes to the Genera and Species described in the Paleontologia Indica up to 1891, to the Memoirs, Vols. I—XX, and to the Records, Vols. I—XXX, have been printed for sale. GEOLOGICAL SURVEY OF INDIA. —_—_—>——___—_ Director. Sm Tomas H. Hotrann, K.C.1.E., D.Sc., F.R.S., AROS, E.G.S. Superintendents. T. H. D. LaToucue, B.A. (Cantab.), F.G.S. : C. S. Mrppnemiss, B.A. (Cantab.) F.G.S. § H. H. Haypen, B.A., R.E. (Dub.), F.G.S. Assistant Superintendents. P. N. Darta, B.Sc. (London) : E. W. Veepensure, B.L., B.Sc. (France), A.R.S.M., A.R.C.S., F.G.S. : L. Leigh Fermor, A.R.S.M., B.Sc. (London), F.G.S. : Guy E. Pitcri, B.Sc. (London), F.G.S.: G. H. Treper, B.A. (Cantab.) : H. Watxer, A.R.C.S., F.G.S., A.Inst.M.M. : E. H. Pascoz, M.A. (Cantab.), B.Sc. (London), F.G.S. : K, A. K. Hattowes, B.A. (Cantab.), A.R.S.M., F.G.S. : ; G. pe P. Correr, B.A. (Dub.) : J. Coaein Brown, B.Sc. (Dunelm), KG.S., F.C.S. : J. J. A. Pace, A.R.S.M., A.I.M.M. (London) : H. C. Jonzs, A.R.S.M., A.B.C.S., F.G.S.: A. M. Heron, B.Sc. (Edin.) : M. Sroart, B.Sc. (Birmingham), F.G.S. : N. D. Darv, B.A. (Bom.), B.Sc. (London), A.R.S.M., Bar.-at-Law. Chemist. W. A. K. Curistiz, B.Sc., Ph.D. Sub-Assistants. . S. Serv Rama Rav, B.A.: M. Vinayak Rao, B.A. Artist. Sh Assistant Curator. H. B. W. Garrick. T. R. Buys. Registrar. A. E. MacAvtay Aupstey, F.Z.S. Geological Museum, Library, and Office, Calcutta. 16 THE NEW YORK ACACLRY OF SQIZCNCESS. MEMOIRS OF THE GEOLOGICAL SURVEY OF INDIA. VOLUME XXXVII. THE MANGANESE-ORE DEPOSITS OF INDIA, by L. LEIGH FERMOR, A.R.S.M., B.Sc. (LONDON), F.G.S., - Assistant Superintendent, Geological Survey of India. PART Il: Geoocy. (MODE OF OCCURRENCE AND ORIGIN.) Published by order of the Government of India. CALCUTTA : SOLD AT THE OFFICE OF THE GEOLOGICAL SURVEY, 27, CHOWRINGHEE ROAD. LONDON : MESSRS. KEGAN PAUL, TRENCH, TRUBNER & CO. BERLIN : MESSRS. FRIEDLANDER UND SOHN. 1909. Srice : Barto 1, 20nd 3, Ro. 3 cach: Fart 4, Ro. 5 ; ov Ro. 8 per volume of 4 parte. MEMOIRS OF THE GEOLOGICAL SURVEY OF INDIA. Vou VoL. Vot. VoL. Vou. Voy I. Pt. 1, 1856 (out of print) : Coal and Iron, of Talchir.—Talchir Coal-field.— Gold-yielding deposits of Upper Assam.—Gold from Shué-gween. Pt. 2, 1858 (out of print) : Geological structure of a portion of Khasi Hills.— Geological structure of Nilgiri Hills (Madras). Pt. 3, 1859 (out of print) : Geological structure and physical features of districts of Bankura, Mid- napore, and Orissa.—Laterite of Orissa.—Fossil fish-teeth of genus Ceratodus, from Maledi, south of Nagpur. IE. Pt. 1, 1860 (out of print) : Vindhyan rocks, and their associates in Bundel- kand. Pt. 2, 1860 (out of print) : Geological structure of central portion of Nerbudda District.—Tertiary and alluvial deposits of central portion of Nerbudda Valley.—Geological relations and probable age of systems of rocks in Central India and Bengal. IIL. Pt. 1, 1863 (owt of print): Raniganj Coal-field.—Additional remarks on systems of rocks in Central India and Bengal.—Indian Mineral Statis- ~ tics, I. Coal. Pt. 2, 1864 (out of print): Sub-Himalayan Ranges between Ganges and Ravi. IV. Pt. 1, 1863 (out of print): Cretaceous Rocks of Trichinopoly District, Madras. Pt. 2, 1864 (out of print) : Districts of Trichinopoly, Salem, etc. Pt. 3, 1865 (out of print) : Coal of Assam, etc. V. Pt. 1, 1865 (out of print) : Sections across N.-W. Himalaya, from Sutlej to Indus.—Gypsum of Spiti. Pt. 2, 1866 (out of print) : oe of Bom- bay. Pt. 5, 1866 (out of print) : Jheria Coal-field.—Geological Observa- tions on Western Tibet. VI. Pt. 1, 1867 (out of print): Neighbourhood of Lynyan, etc., in Sind.— Geology of portion of Cutch. Pt. 2, 1867, Rep. 1908 (price 2 Rs.) : Bokaro Coal-field.—Ramgarh Coal-field.—Traps of Western and Central India. Pt. 3, 1869 (price 2 Rs. 8 As.) : Tapti and Nerbudda Valleys. — Frog-beds in Bombay.—Ozyglossus pusillus. VII. Pt. 1, 1869 (price 3 Rs.) : Vindhyan series.—Mineral Statistics.—Coal.— Shillong Plateau. Pt. 2, 1870 (price 1 Re.) : Karharbdri Coal-field.— Deoghar Coal-field. Pt. 3, 1871 (out of print): Aden water-supply.— Karanpura Coal-fields. VEEI. Pt. 1, 1872 (price 4 Rs.).: Kadapah and Karnul Formations in Madras © Presidency. Pt. 2, 1872 (price 1 Re.) : Itkhuri Coal-field.—Daltonganj Coal-field.—Chope Coal-field. IX. Pt. 1, 1872 (price 4 Rs.) : Geology of Kutch. Pt. 2, 1872 (price 1 Re.) : Geology of Nagputr.—Geology of Sirban Hill.—Carboniferous Am- monites. X. Pt. 1 (price 3 Rs.) : Geology of Madras.—Satpura Coal-basin. Pt. 2, 1874 (price 2 Rs.) : Geology of Pegu. XI. Pt. 1, 1874 (price 2 Rs.) : Geology of Darjiling and Western Duars. Pt. 2, 1876 (price 3 Rs.) : Salt-region of Kohat, Frans-Indus. XE. Pt. 1, 1877 (price Bee South Mahratta Country. Pt. 2, 1876 (price Rs.) : Coal-fields of Naga Hills. XIII. Pt. 1, 1877 (price 2 Rs. 8 As.) : Wardha Valley Coal-field. 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Pt. 3, 1883 (price 1 Re. ys Catalogue of Indian Earthquakes. Pt. 4, 1883 (out ‘of print) : Geology of parts of Manipur and Naga Hills. XX. Pt. 1, 1883 (owt of print) : Geology of Madura and Tinnevelly. Pt. 2, 1883 (out of print) ; Geological notes on Hills in neighbourhood of Sind and Punjab Frontier between Quetta and Dera Ghazi Khan. XXI. Pt. 1, 1884 (out of print) : Geology of Lower Narbada Valley. Pt. 2, 1884 (out of print) : Geology of Kathiawar. Pt. 3, 1885 (out of print) : Coal- field oi South Rewah. Pt. 4, 1885 (owt of print) : Barren Island. XXII. 1883 (price 5 Rs.) : Geology of Kashmir, Chamba, and Khagan. XXIII. 1891 ‘er 5 Rs.) : Geology of Central Himalayas. XXIV. Pt. ne 87 (out of print) : Southern Coal-fields of Sdtpura Gondwana basin. , 1890 (owt of print) : Geology of Sub-Himalaya of Garhwal and Ringun Pt. 3, 1890 (out of print): Geology of South Malabar, be- tween Beypore and Ponnani Rivers. XXY. 1896 (out of print) : Geology of Bellary District, Madras Presidency. XXVI. 1896 (out of print) : Geology of Hazara. XXXVITI. Pt. 1, 1895 (owt of print): Marine Fossil from Miocene of Upper Burma. Pt. 2, 1897 (owt of print) : Petroleum in Burma and its teckni- cal exploitation. XXVIII. Pt. 1, 1898 (price 2 Rs.) : Geological Structure of Chitichun region.— Allahbund in north-west of Rann of Kuchh. —Geology of parts of Myin gyan, Magwé and Pakokku Districts, Burma.—Geology of Mikir Hills in Assam.—Geology of Tirah and Bazdr valley. Pt. 2, 1900 (owt of print) : Charnockite Series, group of Archzan Hypersthenic Rocks in Peninsular India. XXIX. 1900 (price 5 Rs.) : Earthquake of 12th June 1897. ’ XXX. Pt. 1, 1900 (price 2 Rs.) : Aftershocks of Great Earthquake of 12th June 1897. Pt. 2, 1900 (price 1 Re.) : Geology of neighbourhood of Salem, ' Madras Presidency. Pt. 3, 1901 (price 1 Re.): Sivamalai Series of Elzolite-Syenites and Corundum Syenites. Pt. 4, 1901 (price 1 Re.): Geological Congress of Paris. XXXI. 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Pt. 4, 1908 (price ies J Geology of Persian Gulf and adjoining portions of Persia ané XXXV. Pi 1 P1002 (price 2 Rs.) : Geology of Western Rajputana. Pt. 2, 1903 (price 1 Re.) : Aftershocks of Great Earthquake of 12th June 1897. Pt. 3, 1904 (price 1 Re.) : Seismic phenomena in British India and their connection with its Geology. Pt. 4 (in the Press) : Geology of Andaman Islands, with references to Nicobars. XXXVI. Pt. 1, 1904 (price 4 Rs.) : Geology of Spiti. Pt. 2, 1907 (price 3 Rs.) : Geology of Provinces of Tsang and U in Central "Tibet. _ XXXVII. Manganese-Ore Deposits of India. Part 1 (price 3 Rs.) : Introduction and Mineralogy. Part 2 (price 3 Rs.) : Geology. Part 3 (price 3 Rs.) : Economics and Mining. Part 4 (price 5 Rs.) : Description of Deposits (in the Press’. . XXXVIII. (Jn the Press) : Kangra Earthquake of 4th April 1905. 3 PALA;ONTOLOGIA INDICA, (Ser. I, III, V, VI, VIII.)—CRETACEOUS FAUNA OF SOUTHERN INDIA, by ¥ S'TOLICZKA, except Vou. I, Pt. 1, by H. F. BLANFORD. Ser. I & III. yon I. The Cephalopoda (1861-65), pp. 216, pls. 94 (6 double). V.—Vot. 11. The Gastropoda (1867-68), pp. xiii, 500, a3 es Vi.—Vot. 111. The Pelecypoda (1870-71), pp. xxii, 537, p VIII.—Vot. IV. The Branchiopoda, Ciliopoda, irs eae hy Banik etc. (1872- 75), pp. v, 202, pls. 2Y. (Ser. II, XI, XII.}—THE FOSSIL FLORA OF THE GONDWANA SYSTEM, by O. FEISTMANTEL, except Vor. I, Pt. 1, by T. OLDHAM and J. MORRIS. Vou. I, pp. xviii, 233, pls. 72. 1863-79. Pt. 1; Rajmahal Group, Rajmahal Hills, Pt. 2; The same (continued). Pt. 3; Plants from Golapili. Pt. 4; Outliers on the Madras Coast. Vou. II, pp. xli, 115, pls. 26. 1876-78. Pt. 1; Jurassic Flora of Kach. Pt. 2; Flora of the Jabalpur Group. Vou. III, pp. xi, yee pls. 80 e double) (I-XXXI+IA—XLVIIA). 1879-81. Pt. 1; he Flora of the Talchir-Karharbari beds. Pt. 2; The Flora of the Dante and Panchet Divisions. Pt. 3; The same (concluded). Vou. IV, pp. xxvi, 25+66, pls. 35 (2 double) (I-XXV+IA—XLVA). Ft. 1 (1882); Fossil Flora of the South Rewah Gondwana basin. Pt. 2 (1886); Fossil Flora of some of the coal-fields in Western Bengal. (Ser. IX.)—JURASSIC FAUNA OF KACH. Vot. I (1873-76). The Cephalopoda, by W. WAAGEN, pp. i, 244, pls. “ (6 deste Vor. II, pt. 1 (1893). The Echinoidea of Kach, by J. W. Grecory, pp. 12, pls. Vou. II, pt. 2 (1900). The Corals, by J. W. Geamenees pp. 196, Toe. pi pls. 26. Vom III, pt. 1 (1900). The Brachiopoda, by F. L. Krrcur, pp. 87, pls. 15. Vou. III, pt. 2 (1903). raat tas ue : Genus Trigonia, by F. L. Krrcntn, pp. 122, pls. 10. (Ser. IV..—INDIAN PRE-TERTIARY VERTEBRATA. Vou. I, pp. vi, 137, pls. 26. 1865-85 Pt. 1 (1865); The Vertebrate Fossils from the Panchet rocks, by T. H. Huxtey. Pt. 2 (1878); The Vertebrate ae of the Kota-Maleri Group, by Simm P. pr M. GREY Ecerton, L. C. M1Att, and W. T. Branrorp. Pt. 3 (1879); Reptilia and Batrachia, by R. Lypexker. Pt. 4 (1885); The Labyrinthodont from the Bijori group, “by R. Lypexxer. Pt. 5 (1885); The Reptilia and Amphibia of the Maleri and Denwa groups, by R. LyprKKer. (Ser. X.)-INDIAN TERTIARY AND POST-TERTIARY ee by R. LYDEKKER, except Vot. I, Pr. 1, by R. B. FOOT Vou. I, pp. xxx, ae pls. 50. 1874-80. Pt. 1; Rhinoceros decom Pt. 2; Molar h and other remains of Mammalia. Pt. 3; Crania of Ruminants. Pt. ve Supplement to Pt. 3. Pt. 5; Siwalik A Narbada Proboscidia. 4 Vor. II, pp. xv, 563, pls. 45. 1881-84. Pt. 1; Siwalik Rhinocerotide. Pt. 2: Supple- ment to Siwalik and Narbada Proboscidia. Pt 3; Siwalik and Narbada Equide. Pt. 4; Siwalik Camelopardalide. Pt. 5; Siwalik Selenodont Suina, etc. Pe 6; Siwalik and Narbada Carnivora. Vou. III, pp. xxiv, 264, pls. 38. 1884-86. Pt. 1; Additional Siwalik Perissodactyla ane Proboscidia. Pt. 2; Siwalik and Narbada Bunodont Suina. Pt. 3; ? Rodents and new Ruminants from the Siwaliks. Pt. 4; Siwalik Birds. Pt. 5; Mastodon Teeth from Perim Island. Pt. 6; Siwalik and Nar- bada Chelonia. Pt. 7; Siwalik Crocodilia, Lacertilia and Ophidia, Pt. 8; Tertiary Fishes. Vor. IV, pt. 1 (1886). Siwalik Mammalia (Supplement 1), pp. 18, pls. 6. Vou. IV, pt. 4 (1886). The Fauna of the Karnul caves : and addendum to pt. 1; pp. 4 (19—58), pls. 5 (vii—xi). Vot. IV, pt. 3, 1887. ) Eocene Chenolia from the Salt-range; pp. 7 (59—65), pls. 2 (xii— xiii). _ - (Sex, VII, XIV.)—TERTIARY AND UPPER CRETACEOUS FAUNA OF WESTERN INDIA, > oral DUNCAN and W. PERCY SLADEN, except Pt. 1, by Vou. 1, pp. 16+4110+382+-91—599, pls. 5+28+4+58+13=104. 1871—85. Pt. 1: Tertiary Crabs from Sind and Kach. Pt. 1 (new 2): Sind Fossil Corals and Alcyonaria; by P. Martin Duncan. Pt. 3: The Fossil Echinoidea of Sind : Pas 1, The Cardita beaumonti beds; Fas. 2, The Ranikot Series in Western ‘Sind; Fas. 3, ‘Vhe Khirthar Series ; Fas. 4, The Nari (Oligocene) Series ; Fas 5, The Gaj (Miocene) Series; Vas. 6, The Makran (Pliocene) Series ; by Duncan and Sladen. Pt. 4: The Fossil Echinoidea of Kach and Kattywar; by Duncan, Sladen and Blanford. (Ser. XIII.)—SALT-RANGE FOSSILS, by WILLIAM WAAGEN, Pu.D. Productus-Limestone Group : Vot. I, pt. A (1879). Pisces, Cephalopoda, pp. 72, pls. 6. ne o of 3, 2 (1880). Gastropoda and supplement to pt. 1, ae (73—183), pls. 10 (1 double), (vii— By if - », 35 (1881). Pelecypoda, pp. 144 (185—328), pls. 8 (xvii—xxiy). ~ PA - »» 4 (1882—85). Brachiopoda, pp. 442 (329—770), pls. 62 (xxv—Ixxxvi). a o ns », © (1885). Bryozoa—Annelidea—EKEchinodermata, pp. 64 (771—834), pls. 10 (Ilxxxvii—xcvi). - S es », 6 (1886). Coelenterata, pp. 90 (835-924), pls. 20 (xevii—cxvi). er - a »» 7 (1887). Saat Protozoa, pp. 74 (926-- 998), pls. 12 (exvii—exxviii). Fossils from the Ceratite Formation : Vol. II, pt. 1 (1885). Piscus—Ammonoidea, pp. 324, pls. 40. Cfalogical Results : Vol. IV, pt. 1 (1889), pp. 1—88, pls. 4. ”? ” ” ” 2 (1 891), p pp- 89—242, pls. 8. (Ser. XV.)—HIMALAYAN FOSSILS. shia 2 and liassic faunz of the exotic blocks of Malla Johar in the Bhot Mahals of Kumaon : Vol. I, pt. I (1808), by Dr. C. Diener, pp. 100, pls. 16 (1 double). Anthracolithic Fossils of Kashmir and Spiti : Vol. I, pt. 2 (1899), by Dr. C. Diener, pp. 96, pls. 8. The eee choni?stons Fauna of Chitichun No. I: Vol. I, pt. 3 (1897), by Dr. C. Diener, pp. 105, pls. 13. The Permian Fossils of the ——— Shales of Kumaon and Garhwal : Vol. I, pt. 4 (1897), by Dr. C. Diener, pp. 54, : The aes Hoste of the eel Himalayas : Vol. I, pt. 5 (1903), by Dr. C. Diener, pp. 204, pls. 10. The ts shalannds of the Lower Trias: Vol. II, pt. 1 (1897), by Dr. C. Diener, pp. 182, pls. 23. The ‘Cephalopoda of the Muschelkalk : Vol. II, pt. 2 (1895), by Dr. C. Diener, pp. 118, 1 Wyse Triassic Cephalopoda Faunz of the Himalaya: Vol. III, pt. 1 (1899), by Dr. E. von Mojsisovics, pp. 157, pls. 22. Trias Brachiopoda and Lamellibranchiata : Vol. III, pt. 2 (1899), by Alexander Bittner, pp. 76, pls. 12 (2 double). The Fauna of the Spiti Shales : Vol. IV, pt. 1 (1903), by Dr. V. Uhlig, pp. 132, pls. 18. The Fauna of the Tropites-Limestone of "Byans : Vol. V, Memoir No. i mt 1906), by Dr. C. Diener, pp. 201, pls. 17 (1 double). The Fauna of the Himalayan Muschelkalk : Vol. V, Memoir No. 2 (1907), by Dr. Diener, pp. 140, pls. 17 (2 double). Ladinic, Carnic and Noric faunz of Spiti : Vol. V, Memoir No. 3 (1908), by Dr. C. Diener, pp. 157, pls. 24 (3 double). The Cambrian Fossils of Spiti : Vol. V, Memoir No. 4 (in the Press), by F. R. C. oak Lower triassic Cephalopoda from Spiti, Malla Johar and Byans : Vol. VI, Memoir No. 1 (in the Press), by Drs. A. von Krafft and C. Diener. The Fauna of the Traumatocrinus Limestone of Painkhanda: Vol. VI, Memoir No. 2 (in the Press), by Dr. C. Diener. C. (Ser. XVI.)—BALUCHISTAN FOSSILS, by FRITZ NOETLING, Pu.D., F.G.S. The Fauna of the Kellaways of Mazar Drik : Vol. I, pt. 1 (1895), pp. 22, pls. 13. The Fauna of the (Neocomian) Belemnite Beds : Vol. I, pt. 2 (1897), pp. 6, pls. 2. The Fauna of the Upper Cretaceous (Maéstrichtien) Beds of the Mari Hills : Vol. I, pt 3 (1897), pp. 79, pls. 23. (NEW SERIES.) The Cambrian Fauna of the Eastern Salt-range: Vol. I, Memoir 1 (1899), K. Redlich, pp- 14, pl. 1. Notes aioe Morphology of the Pelecypoda: Vol. I, Memoir 2 (1899), Fritz Noetling, pp Bam of ihe Tie Beds of Burma: Vol. I, Memoir 3 (1901), Fritz Noetling, pp. 378, pls. 25. Observations sur quelques Peete Fossiles des Lower Gondwanas: Vol. II, Memoir 1 (1902), R. Zeiller, pp. 39, pls. 7. Permo-Carboniferous (Lower Gondwana) Plants and Vertebrates from Kashmir: (1) Plants, by A. C. Seward; (2} Fishes and Labyrinthodonts, by A. Smith Woodward : Vol. II, Memoir No. 2 (1905), pp. 13, pls. 3. The Lower Palzxozoic Fossils of the Northern ong platen, Upper Burma : Vol. II, Memoir No. 3 (1906), by F. R. C. Reed, pp. 154, 8. The Fauna of the Napeng Beds cr ‘the Rhatic ‘Beds of Upper Burma: Vol. II, Memoir No. 4 (1998), by Miss M. Healey, pp. 88, pls. 9. The Devonian Faunas of the Northern Shan States : Vol. II, Memoir No. 5 (1908), by F. R. C. Reed, pp. 183, pls. 20. The Mollusca of the Ranikot Series: Vol. III, Memoir No. 1 (in the Press), by M. Cossmann and G. Pissarro. On Some Fish-remains from the Beds at Dongargaon. Central Provinces : Vol. III, Memoir No. 3 (1908), by A. Smith Woodward, pp. 6, pl. 1. The price fixed for these lucene is four annas 4 pence 1 minimum charge of 7 wv ) per- single plate, with a —— ss - - - RECORDS OF THE GEOLOGICAL SURVEY OF INDIA. Vou. I, 1868. Part 1 (out of print)—Annual report for 1867. Coal-seams of Tawa valley. Coal in Garrow Hills. Copper in Bundelkhand. Meteorites. Part 2 (out of print).—Coal-seams of neighbourhood of Chanda. Coal near Nagpur. Geo- logical notes on Surat collectorate. Cephalopodous fauna of South Indian cretaceous deposits. Lead in Raipur district. Coal in Eastern Hemisphere. Meteorites. Part 3 (out of print).—Gastropodous fauna of South Indian cretaceous deposits. Notes on route from Poona to Nagpur vid Ahmednuggur, Jalna, Loonar, Yeotmahal, Mangali, and Hingunghat. - Agate-tlake in pliocene (7) deposits of Upper Godavery. Boundary of Vindhyan series in Rajputana. Meteorites. Vou. II, 1869. Part 1 (out of print)—Valley of Poorna river, West Berar. Kuddapah and Kurnool formations. Geological sketch of Shillong plateau. Gold in Singhboom, etc. Wells at Hazareebagh. Meteorites. 5 f Part 2.—Annual report for 1868. Pangshura tecta and other species of Chelonia from newer tertiary deposits of Nerbudda valley. Metamorphic rocks of Bengal. : Part 3.—Geology of Kuch, Western India. Geology and physical geography of Nicobar Islands. Part 4.—Beds containing silicified wood in Eastern Prome, British Burma. Mineralogical statistics of Kumaon division. Coal-field near Chanda. Lead in Raipur district. Meteorites. : E Vou. III, 1870. Part 1.—Annual report for 1869. Geolo By. of neighbourhood of Madras. Alluvial deposits of Irrawadi, contrasted with those of Ganges. Part 2 (out of print).—Geology of Gwalior and vicinity. Slates at Chiteli, Kumaon. Lead vein near Chicholi, Raipur district. Wardha river coal-fields, Berar and Cen- tral Provinces. Coal at Karba in Bilaspur district. Part 3 (out of print)—Mohpani coal-field. Lead-ore at Slimanabad, Jabalpur district. Coal east of Chhatisgarh between Bilaspur and Ranchi. Petroleum in Burma. Petro- leum locality of Sudkal, near Futtijung, west of Rawalpindi. Argentiferous galena and copper in Manbhum. Assays of iron ores. Part 4 (out of print).—Geology of Mount Tilla, Punjab. Copper deposits of Dalbhum and Singbhum : 1.—Copper mines of Singbhum : 2.—Copper of Dalbhum and Sing- bhum. Meteorites. Vou. IV, 1871. Part 1.—Annual report for 1870. Alleged discovery of coal near Gooty, and of indications of coal in Cuddapah district. Mineral statistics of Kumaon division. Part 2.—Axial group in Western Prome. Geological structure of Southern Konkan. Supposed occurrence of native antimony in the Straits Settlements. Deposit in boilers of steam-engines at Raniganj. Plant-bearing sandstones of Godavari valley, on south- ern extensions of Kamthi group to neighbourhood of Ellore and Rajamandri, and on possible occurrence of coal in same direction. Part 3.—Borings for coal in Godavari valley near Dumagudem and Bhadrachalam. _ Narbada , coal-basin. Geology of Central Provinces. Plant-bearing sandstones of Godavari valley. Part 4.—Ammonite fauna of Kutch. Haigur and Hengir (Gangpur) Coal-field. Sandstones = neighbourhood of first barrier on Godavari, and in country between Godavari and ore. Vor. V, 1872. Part 1.—Annual report for 1871. Relations of rocks near Murree (Mari), Punjab. Mineral- ogical notes on gneiss of South Mirzapur and adjoining country. Sandstones in neighbourhood of first barrier on Godavari, and in country between Godavari and 7 Part .—Coasts of Baluchistan and Persia from Karachi to head of Persian Gulf, and some of Gulf Islands. Parts of Kummummet and Hanamconda districts in Nizam’s Dominions. Geology of Orissa. New coal-field in south-eastern Hyderabad (Deccan) territory. : Part 3.—Maskat and Massandim on east coast of Arabia. Example of local jointing. Axial group of Western Prome. Geology of Bombay Presidency. Part 4.—Coal in northern region of Satpura basin. Evidence afforded by raised oyster banks on coasts of India, in estimating amount of elevation indicated thereby. Possible field of coal-measures in Godavari district, Madras Presidency. Lameta cr intra-trappean formation of Central India. Petroleum localities in Pegu. Supposed eozoonal limestone of Yellam Bile. Vou. VI, 1873. Part 1.—Annual report for 1872. Geology of North-West Provinces. Part 2.—Bisrampur coal-field. Mineralogical notes on gneiss of South Mirzapur and ad- joining country. Part 3.—Celt in ossiferous deposits of Narbada valley (Pliocene of Falconer) : on age of deposits, and on associated shells. Barakars (eee) in Beddadanole field, Goda district. Geology of parts of Upper Punjab. Coal in India. Salt-springs of Pegu. ata Part 4.—Iron deposits of Chanda (Central Provinces). Barren Islands and Narkondam. Metalliferous resources of British Burma. Vou. VII, 1874. Part 1 (out of CO ee report for 1873. Hill ranges between Indus valley in Ladak and Shah-i-Dula on frontier of Yarkand territory. Iron ores of Kumaon. Raw materials for iron-smelting in Raniganj field. Elastic sandstone, or so-called Itaco- lumyte. Geological notes on part of Northern Hazaribagh. Part 2 (out of print).—Geological notes on route traversed by Yarkand Embassy from Shah-i-Dula to Yarkand and Kashgar. Jade in Karakas valley, ‘lurkistan. Notes from Eastern Himalaya. Petroleum in Assam. Coal in Garo Hills. Copper in Narbada valley. Potash-sa)+; from East India. Geology of neighbourhood of Mari hill station in Punjab. Part 3.—Geological observations made on a visit to Chaderkul, Thian Shan _ range. Former extension of glaciers within Kangra district. Building and ornamental stones of India. Materials for iron manufacture in Raniganj coal-field. Manganese-ore in Wardha coal-field. Part 4 (out of print).—Auriferous rocks of Dhambal hills, Dharwar district. Antiquity of human race in India. Coal recently discovered in the country of Luni Pathans, south-east corner of Afghanistan. Progress of geological investigation in Godavari district, Madras Presidency. Subsidiary materials for artificial fuel. Vou. VIII, 1875. Part 1.—Annual report for 1874. The Altum-Artush considered from geological point of view. Evidences of ‘ ground-ice’ in tropical India, during Talchir period. Trials of Raniganj fire-bricks. Part 2 (out of print).—Gold-fields of south-east Wynaad, Madras Presidency. Geological notes on Khareean hills in Upper Punjab. Water-becring strata of Surat district. Geology of Scindia’s territories. Part $ (out of print).—Shahpur coal-field, with notice of coal explorations in Narbada region. Coal recently found near Moflong, Khasia Hills. Part 4 (out of print).—Geology of Nepal. Raigarh and Hingir coal-fields. Vor. IX, 1876. Part 1 (out of print).—Annual report for 1875. Geology of Sind. Part 2.—Retirement of Dr. Oldham. Age of some fossil floras in India. Cranium of Stegodon Ganesa, with notes on sub-genus and allied forms. Sub-Himalayan series in Jamu (Jammoo) Hills. Part 3.—Fossil floras in India. Geological age of certain groups comprised in Gondwana series of India, and on evidence they afford of distinct zoological and botanical terres- trial regions in ancient epochs. Relations of fossiliferous strata at Maleri and Kota, near Sironcha, C. P. Fossil mammalian faune of India and Burma. Part 4.—Fossil floras in India. Osteology of Merycopotamus dissimilis. Addenda and Corrigenda to paper on tertiary mammalia. Plesiosaurus in India. Geology of Pir Panjal and neighbouring districts. 8 ° Vou. X, 1877. Part 1.—Annual report for 1876. Geological notes on Great Indian Desert between Sind and Rajputana. Cretaceous genus Omphalia near Nameho lake, Tibet, about 75 miles north of Lhassa. Estheria in Gondwana formation. Vertebrata from Indian tertiary and secondary rocks. New Emydine from the upper tertiaries of Northern Punjab. Observations on under-ground temperature. Part 2.—Rocks of the Lower Godavari. ‘ Atgarh Sandstones’ near Cuttack. Fossil floras jn India. New or rare mammals from the Siwaliks. Arvali series in North-eastern Rajputana. Borings for coal in India. Geology of India. Part 3.—Tertiary zone and underlying rocks in North-west Punjab. Fossil floras in India. Erratics in Potwar. Coal 2xplorations in Darjiling district. Limestones in neighbour- hood of Barakar. Forms of blowing-machine used by smiths of Upper Assam. Analyses of Raniganj coals. Part 4.—Geology of Mahanadi basin and its vicinity. Diamonds, gold, and lead ores of Sambalpur district. ‘Eryon Comp. Barrovensis,’ McCoy, from Sripermatur group near Madras. Fossil floras in India. The Blaini group and ‘Central Gneiss’ in Simla Himalayas. Tertiaries of North-West Punjab. Genera Cheromeryx und Rhagatherium. Vou. XI, 1878. Part 1.—Annual report for 1877. Geology of Upper Godavari basin, between river Wardha and Godavari, near Sironcha. Geology of Kashmir, Kishtwar, and Pangi. See mammals. Paleontological relations of Gondwana system. ‘Erratics in unjab.’ Part 2.—Geology of Sind (second notice). Origin of Kumaun lakes. Trip over Milam ass, Kumaun. Mud volcanoes of Ramri and Cheduba. Mineral resources of Ramri, Cheduba and adjacent islands. Part 3.—Gold industry in Wynaad. Upper Gondwana series in Trichinopoly and Nellore- Kistna districts. Senarmontite from Sarawak. Part. 4.—Geographical distribution of fossil organisms in India. Submerged forest on’ Bombay Island. Vor. XII, 1879. Part 1.—Annual report for 1878. Geology of Kashmir (third notice). Siwalik mammalia. Siwalik birds. Tour through Hangrang and Spiti. Mud eruption in Ramri Island (Arakan). Braunite, with Rhodonite, from Nagpur, Central Provinces. Palzontologi- cal notes from Satpura coal-basin. Coal importations into India. Part 2.—Mohpani coal-field. Pyrolusite with Psilomelane at Gosalpur, Jabalpur district. Geological reconnaissance from Indus at Kushalgarh to Kurram at Thal on Afghan frontier. Geology of Upper Punjab. Part 3.—Geological features of northern Madura, Pudukota State, and southern parts of Tanjore and Trichinopoly districts included within limits of sheet 80 of Indian Atlas. Cretaceous fossils from Trichinopoly district, collected in 1877-78. Sphenophyllum and other Equisetacee with reference to Indian form Trizygia Speciosa, Royle (Spheno- phyllum Trizygia, Ung.). Mysorin and Atacamite from Nellore district. Corundum from Khasi Hills.. Joga neighbourhood and old mines on Nerbudda. Part 4.— Attock Slates’ and their probable geological position. Marginal bone of unde- scribed tortoise, from Upper Siwaliks, near Nila, in Potwar, Punjab. Geology of North Arcot district. Road section from Murree to Abbottabad. Vox. XITI, 1880. Part 1.—Annual report for 1879" Geology of Upper Godavari basin in neighbourh Sironcha. Geology of Ladak and neighbouring districts. Teeth of fossil taken ae Ramri Island and Punjab. Fossil genera Noggerathia, Etbg., Noggerathiopsis, Fstm., Retna ee Schmalh., in palzozoic and secondary rocks of Europe, Asia, and : oy ras a ag from Kattywar, Shekh Budin, and Sirgujah. Volanic foci ‘art 2.—Geological notes. Palzontological notes on lower trias of Himalayas. Artesi wells at Pondicherry, and possibility of finding sources of water-supply EA Wate ar Part 3.—Kumaun lakes. Celt of paleolithic type in Punjab. Palzontological notes from Karharbari and South Rewa coal-fields. Correlation of Gondwana flora with other floras. - Artesian wells at Pondicherry. Salt in Rajputana. Gas and mud eruptions on Arakan coast on 12th March 1879 and in June 1845, 9 Part 4.—Pleistocene deposits of Northern Punjab, and evidence they afford of extreme climate during portion of that period. Useful minerals of Arvali region. Correlation of Gondwana flora with that of Australian coal-bearing system. Reh or alkali soils and on well waters. Reh soils of Upper India. Naini Tal landslip, 18th Septem- ber 1880. Z Vor. XIV, 1881. Part 1.—Annual report for 1880. Geology of part of Dardistan, Baltistan, and neighbour- ing districts. Siwalik carnivora. Siwalik group of Sub-Himalayan region. South Rewah Gondwana basin. Ferruginous beds associated with basaltic rocks ‘of north- eastern Ulster, in relation to Indian laterite. Rajmahal plants. Travelled blocks of the Punjab. Appendix to ‘ Palzontological notes on lower trias of Himalayas.’ Mam- malian fossils from Perim Island. Part 2.—Nahan-Siwalik unconformity in North-Western Himalaya. Gondwana verte- brates. Ossiferous beds of Hundes in Tibet. Mining records and mining record office of Great Britain; and Coal and Metalliferous Mines Act of 1872 (England). Cobaltite and danaite from Khetri mines, Rajputana; with remarks on Jaipurite (Syepoorite}. Zinc-ore (Smithsonite and Blende) with barytes in Karnul district, Madras. Mud eruption in island of Cheduba. Part 3.—Artesiarn borings in India. Oligoclase granite at Wangtu on Sutlej, North-West Himalayas. Fish-palate from Siwaliks. Paleontological notes from Hazaribagh and Lohardagga districts. Fossil carnivora from Siwalik hills. ~ < Part 4.—Unification of geological nomenclature and cartography. Geology of Arvali region, central and eastern. Native antimony obtained at Pulo Obin, near Singapore. Tur- gite from Juggiapett, Kistnah district, and zinc carbonate from Karnul, Madras. Section from Dalhousie to Pangi, vid Sach Pass. South Rewah Gondwana basin. Submerged forest on Bombay Island. Vou. XV, 1882. Part 1.—Annual report for 1881. Geology of North-West Kashmir and Khagan. Gond- wana labyrinthodonts. Siwalik and Jamna mammals. Geology of Dalhousie, North- West Himalaya. Palm leaves from (tertiary) Murree and Kasauli beds in India. Iridosmine from Noa-Dihing river, Upper Assam, and Platinum from Chutia Nagpur. On (1) copper mine near Yongri hill, Darjiling district; (2) arsenical pyrites in same neighbourhood; (3) kaolin at Darjiling. Analyses of coal and fire-clay from Makum coal-field, Upper Assam. Experiments on coal of Pind Dadun Khan, Salt-range, with reference to production of gas, made April 29th, 1881. Proceedings of International Congress of Bologna. Part 2.—Geology of Travancore State. Warkilli beds and reported associated deposits at Quilon, in Travancore. Siwalik and Narbada fossils. Coal-bearing rocks of Upper Rer and Mand rivers in Western Chutia Nagpur. Pench river coal-field in Chhind- wara district, Central Provinces. Berings for coal at Engsein, British Burma. Sap- phires in North-Western Himalaya. Eruption of mud volcanoes in Cheduba. Part 3.—Coal of Mach (Much) in Bolan Pass, and of Sharigh on Harnai route between Sibi and Quetta. Crystals of stilbite from Western Ghats, Bombay. Traps of Darang and Mandi in North-Western Himalayas. Connexion between Hazara and Kashmir - series. Umaria coal-field (Sonth Rewah Gondwana basin). Daranggiri coal-field, Garo Hills, Assam. Coal in Myanoung division, Henzada district. Part 4 (out of print).—Gold-fields of Mysore. Borings for coal at Beddadanol, Godavari district, in 1874. Supposed occurrence of coal on Kistna. Vor. XVI, 1883. * Part 1.—Annual report for 1882. Richthofenia, Kays (Anomia Lawrenciana, Koninck). Geology of South Travancore. Geology of Chamba. Basalts of Bombay. Part 2.—Synopsis of fossil vertebrata of India. Bijori Labyrinthodont. Skuli of Hippo. therium antilopinum. Iron ores, and subsidiary materials for manufacture of iron, in north-eastern part of Jabalpur district. Laterite and other manganese-ore occurring at Gosulpore, Jabalpur district. Umaria coal-field. Part 3.—Microscopic structure of some Dalhousie rocks. Lavas of Aden. Probable occur- rence of Siwalik strata in China and Japan. Mastodon angustidens in India. Traverse between Almora and Mussooree. Cretaceous coal-measures at Borsora, in Khasia Hills, near Laour, in Sylhet. 10 Part 4.—Palxontological notes from Daltonganj and Hutar coal-fields in Chota Nagpur. Altered basalts of Dalhousie region in North-Western Himalayas. Microscopic struc- ture of some Sub-Himalayan rocks of tertiary age. Geology of Jaunsar and Lower ee Traverse through Eastern Khasia, Jaintia, and North Cachar Hills. ative lead from Maulmain and chromite from the Andaman Islands. Fiery eruption from one of mud volcanoes of Cheduba Island, Arakan. Irrigation from wells in North-Western Provinces and Oudh. Vout. XVII, 1884. Part 1.—Annual report for 1883. Smooth-water anchorages or mud-banks of Narrakal and - Alleppy on Travancore coast. Billa Surgam and other caves in Kurnool district. Geology of Chuari and Sihunta parganas of Chamba. Lyttonia, Waagen, in Kuling series,of Kashmir. Part 2.—Earthquake of 3lst December 1681 Microscopic structure of some Himalayan granites and gneissose granites. Choi coal exploration. Re-discovery of fossils in Siwalik beds. Mineral resources of the Andaman Islands in neighbourhood of Port Blair. Intertrappean beds in Deccan and Laramie group in Western North America. Part 3 (out of print).—Microscopic structure of some Arvali rocks. Section along Indus from Peshawar Valley to Salt-range. Sites for boring in Raigarh-Hingir coal-field (first notice). Lignite near Raipore, Central Provinces. Turquoise mines of Nishapar, Khorassan. Fiery eruption from Minbyin mud volcano of Cheduba Island, Arakan. Langrin coal-field, South-Western Khasia Hills. Umaria coal-field. Part 4.—Geology of part of Gangasulan pargana of British Garhwal. Slates and schists imbedded in gneissose granite of North-West Himalayas. Geology of Takht-i-Sulei- man. Smooth-water anchorages of Travancore coast. Auriferous sands of the Suban- siri river. Pondicherry lignite, and phosphatic rocks at Musuri. Billa Surgam caves. Vor. XVIII, 1885. Part 1.—Annual report for 1884. Country between Singareni coal-field and Kistna river. Geological sketch of country between Singareni coal-field and Hyderabad. Coal and limestone in Doigrung river near Golaghat, Assam. Homotaxis, as illustrated from Indian formations. Afghan field notes. Part 2.—Fossiliferous series in Lower Himalaya, Garhwal. Age of Mandhali series in Lower Himalaya. Siwalik camel (Camelus Antiquus, nobis ex Falc. and Caut. MS.). Geology of Chamba. Probability of obtaining water by means of artesian wells in plains of Upper India. Artesian sources in plains of Upper India. Geology of Aka Hi Alleged tendency of Arakan mud volcanoes to burst into eruption most frequently during rains. Analyses of phosphatic nodules and rock from Mussooree. Part 3.—Geology of Andaman Islands. Third species of Merycopotamus. Percolation as affected by current. Pirthalla and Chandpur meteorites. Oil-wells and coal in Thayetmyo district, British Burma. Antimony deposits in Maulman district. Kash- mir earthquake of 30th May 1885. Bengal earthquake of 14th July 1885. Part 4.—Geological work in Chhattisgarh division of Central Provinces. Bengal earth- quake of 14th July 1885. Kashmir earthquake of 30th May 1885. Excavations in Billa Surgam caves. Nepaulite. Sabetmahet meteorite. Vor. XIX, 1886. Part 1.—Annual report for 1885. International Geological Congress of Berlin. Palzozoic Fossils in Olive group of Salt-range. Correlation of Indian and Australian coal- bearing beds. Afghan and Persian Field-notes. Section from Simla to Wangtu, and petrological character of Amphibolites and Quartz Diorites of Sutlej valley. d Part 2.—Geology of parts of Bellary and Anantapur districts. Geology of Upper Dehing basin in Singpho Hills. Microscopic characters of eruptive rocks from Central Hima- layas. Mammalia of Karnul Caves. Prospects of finding coal in Western Rajputana. Olive group of Salt-range. Boulder-beds of Salt-range. Gondwana Homotaxis. Part 8. ological sketch of Vizagapatam district, Madras. Geology of Northern Jesal- mer. Microscopic structure of Malaini rocks of Arvali region. Malanjkhandi copper- ore in Balaghat district, C. P. _ ; wy 2 f Part 4.—Petroleum in India. Petroleum exploration at Khatan. Boring in Chhattisgarh coal-fields. Field-notes from Afghanistan: No. 3, Turkistan. Fiery eruption from one of mud volcanoes of Cheduba Island, Arakan. Nammianthal aerolite. Analysis of gold dust from Meza valley, Upper Burma. 11 Voi. XX, 1887. ; Part 1.—Annual report for 1886. Field-notes from Afghanistan: No. 4, from Turkistan to India. Physical geology of West British Garhwal; with notes on a route traversed through Jaunsar-Bawar and Tiri-Garhwal. Geology of Garo Hills. Indian intage- stones. Soundings recently taken off Barren Island and Narcondam. Talchir boulder- beds. Analysis of Khosphatic Nodules from Salt-range, Punjab. Part 2.—Fossil vertebrata of India. Echinoidea of cretaceous series of Lower Narbada Valley. Field-notes : No. 5—to accompany geological sketch map of Afghanistan and North-Eastern Khorassan. Microscopic structure of Rajmahal and Deccan traps. Dolerite of Chor. Identity of Olive series in east with speckled sandstone in west of Salt-range in Punjab. : Part 3.—Retirement of Mr. Medlicott. J. B. Mushketoff’s Geology of Russian Turkistan. Crystalline and metamorphic rocks of Lower Himalaya, Garhwal, and Kumaun, Sec- tion I. Geology of Simla and Jutogh. ‘ Lalitpur ’ meteorite. : Part _4.—Points in Himalayan geology. Crystalline and metamorphic rocks of Lower Himalaya, Garhwal, and Kumaun, Section II. Iron industry of western portion of Raipur. Notes on Upper Burma. Boring exploration in Chhattisgarh coal-fields. (Second notice). Pressure Metamorphism, with reference to foliation of Himalayan Gneissose Granite. Papers on Himalayan Geology and Microscopic Petrology. Vou. XXI, 1888. Part 1.—Annual report for 1887. Crystalline and metamorphic rocks of Lower Himalaya, Garhwal, and Kumaun, Section III. Birds’-nest of Elephant Island, Mergui Archi- pelago. Exploration of Jessalmer, with a view to discovery of coal. Facetted pebble from boulder bed (‘speckled sandstone’) of Mount Chel in Salt-range, Punjab. Nodular stones obtained off Colombo. é Part 2.—Award of Wollaston Gold Medal, Geological Society of London, 1888. Dharwar System in South India. Igneous rocks of Raipur and Balaghat, Central Provinces. Sangar Marg and Mehowgale coal-fields, Kashmir. ; Part 3.—Manganese Iron and Manganese Ores of Jabalpur. ‘ The Carboniferous Glacial Period.’ Pre-tertiary sedimentary formations of Simla region of Lower Himalayas. Part 4.—Indian fossil vertebrates. Geology of North-West Himalayas. Blown-sand rock sculpture. Nummulitesin Zanskar. Mica traps from Barakar and Raniganj. Vou. XXII, 1889. Part _1.—Annual report for 1888. Dharwar System in South India. Wajra Karur diamonds, and M. Chaper’s alleged discovery of diamonds in pegmatite. Generic posi- tion of so-called Plesiosaurus Indicus. Flexible sandstone or Itacolumite, its nature, mode of occurrence in India, and cause of its flexibility. Siwalik and Narbada Chelonia. ES Part 2.—Indian Steatite. Distorted pebbles in Siwalik conglomerate. ‘ Carboniferous Glacial Period.’ Oil-fields of Twingoung and Beme, Burma. Gypsum of Nehal Nadi, Kumaun. Materials for pottery in neighbourhood of Jabalpur and Umaria. Part 3.—Coal outcrops in Sharigh Valley, Baluchistan. Trilobites in Neobolus beds of Salt-range. Geological notes. Cherra Poonjee coal-field, in Khasia Hills. Cobalti- ferous Matt from Nepal. President of Geological Society of London on International Geological Congress of 1888. Tin-mining in Mergui district. Part 4.—ULand-tortoises of Siwaliks. Pelvis of a ruminant from Siwaliks. Assays from Sambhar Salt-Lake in Rajputana. Manganiferous iron and Manganese Ores of Jabal- pur. Palagonite-bearing traps of Rajmahdal hills and Deccan. Tin-smelting in Mala Peninsula. Provisional Index of Local Distribution of Important Minerals, Miscel- laneous Minerals, Gem Stones and Quarry Stones in Indian Empire. Part 1. Vou. XXIII, 1890. Part 1.—Annual report for 1889. Lakadong coal-fields, Jaintia Hills. Pectoral and pelvic girdles and skull of Indian Dicynodonts. Vertebrate remains from Nagpur district (with description of fish-skull). Crystalline and metamorphic rocks of Lower Hima- layas, Garhwdl and Kumaun, Section IV. Vivalves of Olive-group, Salt-range. Mud-banks of Travancore coasts. ; Part 2.—Petroleum explorations in Harnai district, Baluchistan. Sapphire Mines of Kashmir. Supposed Matrix of Diamond at Wajra Karur, Madras. Sonapet Gold- field. Field notes from Shan Hills (Upper Burnal: New species of Syringospheride. 12 Part 3.—Geology and Economic Resources of Country adjoining Sind-Pishin Railway between Sharigh and Spintangi, and of country between it and Khattan. Journey . through India in 1888-89, by Dr. Johannes Walther. Coal-fields of Lairungao, Mao- sandram, and Mao-belar-kar, in the Khasi Hills. Indian Steatite. Provisional Index of Local Distribution of Important Minerals, Miscellaneous Minerals, Gem Stones, and Quarry Stones in Indian Empire. fag ; Part 4.—Geological sketch of Naini Tal; with remarks on natural conditions governing mountain slopes. Fossil Indian Bird Bones. Darjiling Coal between Lisu and Ramthi rivers. Basic Eruptive Rocks of Kadapah Area. Deep-Boring at Lucknow. Coal Seam of Dore Ravine, Hazara. Vou. XXIV, 1891. Part 1.—Annual report for 1890. Geology of Salt-range of Punjab, with re-considered theory of Origin and Age of Salt-Mart. Graphite in decomposed Gneiss (Laterite) in Ceylon. Glaciers of Kabru, Pandim, etc. Salts of Sambhar Lake in Rajputana, and ‘Reh’ from Aligarh in North-Western Provinces. Analysis of Dolomite from Salt- range, Punjab. Part 2.—Oil near Moghal Kot, in Sherdni country, Suleiman Hills. Mineral Oil from Suleiman Hills. Geology of Lushai Hills. Coal-fields in Northern Shan States. Reported Namséka Ruby-mine in Mainglén State. Tourmaline (Schorl) Mines in Mainglon State. Salt-spring near Bawgyo, Thibaw State. Part 3.—Boring in- Daltongunj Coal-field, Palamow. Death of Dr. P. Martin Duncan. Pyroxenic varieties of Gneiss and Scapolite-bearing Rocks. Part 4.—Mammalian Bones from Mongolia. Darjiling Coal Exploration. Geology and Mineral Resources of Sikkim. Rocks from the Salt-range, Punjab. Vou. XXV, 1892. Part 1.—Annual report for 1891. Geology of Thal Chotidli and part of Mari country. Petrological Notes on Boulder-bed of Salt-range, Punjab. Sub-recent and Recent Deposits of valley plains of Quetta, Pishin, and Dasht-i-Bedaolat; with appendices on Chamans of Quetta; and Artesian water-supply of Quetta and Pishin. Part 2 (out of print).—Geology of Saféd Koh. Jherria Coal-field. Part 3.—Locality of Indian Tscheffkinite. Geological Sketch of country north of Bhamo. Economic resources of Amber and Jade mines area in Upper Burma. [Iron-ores and Iron Industries of Salem District. Riebeckite in India. Coal on Great Tenasserim : River, Lower Burma. Part 4.—Oil Springs at Moghal Kot in Shirani Hills. Mineral Oil from Suleiman Hills. New Amber-like Resin in Burma. Triassic Deposits of Salt-range. Vor. XXVI, 1893. Part 1.—Annual report for 1892. Central Himalayas. Jadeite in Upper Burma. Bur- rg new Fossil Resin from Upper Burma. Prospecting Operations, Mergui District, Part 2.—Earthquake in Baluchistan on 20th December 1892. Burmite, new amber-like ma resin from Upper Burma. Alluvial deposits and Subterranean water-supply of ngoon. Part 3.—Geology of Sherani Hills. Carboniferous Fossils from Tenasserim. Boring at Chandernagore. Granite in Tavoy and Mergui. Part 4.—Geology of country between Chappar Rift and Harnai in Baluchistén. Geology of part of Tenasserim Valley with special reference to Tendau-Kamapying Coal-field. Magnetite containing Manganese and Alumina. Hislopite. *: : Vout. XXVII, 1894. ‘Part 1.—Annual report for 1893. Bhaganwala Coal-field, Salt-range, Punjab. Part 2.—Petroleum from Burma. Singareni Coal-field, Hyderabad (Deccan). Gohna Landslip, Garhwal. Part $.—Cambrian Formation of Eastern Salt-range. Giridih (Karharbari) Coal-fields. Chipped (?) Flints in Upper Miocene of Burma. Velates Schmideliana, Chemn., and Provelates grandis, Sow. sp., in Tertiary Formation of India and Burma. Part 4.—Geology of Wuntho in Upper Burma. Echinoids from Upper Cretaceous System of Baluchistan. Highly Phosphatic Mica Peridotites intrusive in Lower Gondwana Rocks of Bengal. Mica-Hypersthene-Hornblende-Peridotite in Bengal. ; Vor. XXVIII, 1895. art 1.—Annual report for 1894. Cretaceous Formation of Pondicherry. Early allusion to Barren Island. Bibliography of Barren Island and Narcondam from 1884 to 1894. 13 Part 2.—Cretaceous Rocks of Southern India and geographical conditions during later cretaceous times. Experimental Boring for Petroleum at Sukkur from October 1893 to March 1895. Tertiary system in Burma. : Part 3.—Jadeite and other rocks, from Tammaw in Upper Burma. Geology of Tochi Valley. Lower Gondwanas in Argentina. : ; Part 4.—Igneous Rocks of Giridih (Kurhurbaree) Coal-field and their Contact Effects. Vindhyan system south of Sone and their relation to so-called Lower Vindhyans. Lower Vindhyan area of Sone Valley. Tertiary system in Burma. Vout. XXIX, 1896. Part 1.—Annual report for 1895. Acicular inclusions in Indian Garnets. Origin and Growth of Garnets and of their Micropegmatitic intergrowths in Pyroxenic rocks. Part 2.—Ultra-basic rocks and derived minerals of Chalk (Magnesite) hills, and other localities near Salem, Madras. Corundum localities in Salem and Coimbatore districts,. Madras. Corundum and Kyanite in Manbhum district, Bengal. Ancient Geography of ‘‘Gondwanaland.’”’ Notes. Part 3.—Igneous Rocks from the Tochi Valley. Notes. Part 4.—Steatite mines, Minbu district, Burma. Lower Vindhyan (Sub-Kaimur) area of Sone Valley, Rewah. Notes. Vou. XXX, 1897. Part 1.—Annual report for 1896. Norite and associated Basic Dykes and Lava-flows in: Southern India. Genus Vertebraria. On Glossopteris and Vertebraria. Part 2.—Cretaceous Deposits of Pondicherri. Notes. Part 3.—Flow structure in igneous dyke. Olivine-norite dykes at Coonoor. Excavations. for corundum near Palakod, Salem District. Occurrence of coal at Palana in Bikanir. Geological specimens collected by Afghan-Baluch Boundary Commission of 1896. Part 4.—Nemalite from Afghanistan. Quartz-barytes rock in Salem District, Madras. Presidency. Worn femur of Hippopotamus irravadicus, Caut. and Falc., from Lower Pliocene of Burma. Supposed coal at Jaintia, Baxa Duars. Percussion Figures on micas. Notes. Vou. XXXI, 1904. Part 1 (out of print).—Prefatory Notice. Copper-ore near Komai, Darjeeling district. Zewan beds in Vihi district, Kashmir. Coal deposits of Isa Khel, Mianwali district, Punjab. Um-Rileng coal-beds, Assam. Sapphirine-bearing rock from Vizagapatam district. Miscellaneous Notes. Assays. Part 2 (out of print).—Lt.-Genl. C. A. McMahon. Cyclobus Haydeni Diener. Auriferous: . Occurrences of Chota Nagpur, Bengal. On the feasibility of introducing modern methods of Coke-making at East Indian Railway Collieries, with supplementary note- by Director, Geological Survey of India. Miscellaneous Notes. Part 3 (out of print).—Upper Paleozoic formations of Eurasia. Glaciation and History of Sind Valley. Halorites in Trias of Baluchistan. Geology and Mineral Resources. of Mayurbhanj. Miscellaneous Notes. f Part 4 (out of print).—Geology of Upper Assam. Auriferous Occurrences of Assam. Curious occurrence of Scapolite from Madras Presidency. Miscellaneous Notes. Index. Vou. XXXII, 1905. Part 1 (out of print).—Review of Mineral Production of India during 1898—1903. Part 2 (out of print).—General report, April 1903 to December 1904. Geoiogy of Pro- vinces of Tsang and U in Tibet. Bauxite in India. Miscellaneous Notes. Part 3 (out of print).—Anthracolithic Fauna from Subansri Gorge, Assam. Elephas ” Antiquus (Namadicus) in Godavari Alluvium. Triassic Fauna of Tropites-Limestone: of Byans. Amblygonite in Kashmir. Miscellaneous Notes. Part 4.—Obituary notices of H. B. Medlicott and W. T. Blanford. Kangra Earthquake of 4th April 1905. Index to Volume XXXII. Vou. XXXII, 1906. Part 1 (out of print).—Mineral Production of India during 1904. Pleistocene Movement in Indian Peninsula. Recent Changes in Course of Nam-tu River, Northern Shan States. Natural Bridge in Gokteik Gorge. Geology and Mineral Resources of Narnaul Dis- trict (Patiala State). Miscellaneous Notes. : : Part 2 (out of print).—General report for 1905. Lashio Coal-field, Northern Shan States. Namma, Mansang and Man-se-le Coal-fields, Northern Shan States, Burma Mis-~ cellaneous Notea 14 / Part 3.—Petrology and Manganese-Ore Deposits of Sausar Tahsil, Chhindwara district, Central Provinces. Geology of parts of valley of Kanhan River in Nagpur and Chhindwara districts, Central Provinces. Manganite from Sandur Hills. Miscella- neous Notes. — Part 4 (out of print).—Composition and Quality of Indian Coals.’ Classification of the indhyan System. Geology of State of Panna with reference to the Diamond g Deposits. Index to Volume XXXIII. Vou. XXXIV, 1906. Part 1.—Fossils from Halorites Limestone of Bambanag Cliff, Kumaon. Upper-Triassic Fauna from Pishin District, Baluchistan. Geology of portion of Bhutan. Coal Occur- rences in Foot-hills of Bhutan. Dandli Coal-field : Coal outcrops in Kotli Tehsil of Jammu State. Miscellaneous Notes. Part 2.—Mineral Production of India during 1905. Nummulites Donvillei, with remarks on Zonal Distribution of Indian Nummulites. Auriferous Tracts in Southern India. Abandonment of Collieries at Warora, Central Provinces. Miscellaneous Notes. Part 3.—Explosion Craters in Lower Chindwin district, Burma. Lavas of Pavagad Hill. Gibbsite with Manganese-ore from Talevadi, Belgaum district, and Gibbsite from Bhekowli, Satara District. Classification of Tertiary System in Sind with reference to Zonal distribution of Eocene Echinoidea. Part 4 (out of print).—Jaipur and Nazira Coal-fields, Upper Assam. Makum Coal-field between Tirap and Namdang Streams.. Kabat Anticline, near Seiktein, Myingyan district, Upper Burma. Asymmetry of Yenangyat-Singu Anticline, Upper Burma. Northern part of Gwegyo Anticline, Myingyan District, Upper Burma. Breynia Maultituberculata, from Nari of Baluchistan and Sind. Index to Volume XXXIV. Vout. XXXV, 1907. Part 1.—General report for 1906. Orthophragmina and Lepidocyclina in Nummulitic Series. Meteoric Shower of 22nd October 1903 at Dokdchi and neighbourhood, Dacca District. Part 2.—Indian Aerolites. Brine-wells at Bawgyo, Northern Shan States. Gold-bearing a of Loi Twang, Shan States. Physa Prinsepii in Maestrichtian strata of uchistan. Miscellaneous Notes. Part 3.—Preliminary survey of certain Glaciers in North-West Himalaya. A.—Notes on certain Glaciers in North-West Kashmir. Part 4.—Preliminary survey of certain Glaciers in North-West Himalaya. B.—Notes on certain Glaciers in Lahaul. C.—Notes on certain Glaciers in Kumaon. Index to Volume XXXY. Vor. XXXVI, 1907-08. Part 1.—Petrological Study of Rocks from hill tracts, Vizagapatam district, Madras Presidency. Nepheline Syenites from hill tracts, Vizagapatam district, Madras Presi- dency. Stratigraphical Position of Gangamopteris Beds of Kashmir. Volcanic out- burst of Late Tertiary Age in South Hsenwi, N. Shan States. New suide from Bugti Hills, Baluchistan. Permo-Carboniferous Plants*from Kashmir. Part 2.—Mineral Production of India during 1906. Ammonites of Bagh Beds. Mis- : eous Notes. Part 3.—Marine fossils in Yenangyaung oil-field, Upper Burma. Fresh-water shells of genus Batissa in Yenangyaung oil-field, Upper Burma. New Species of Dendrophyllia from Upper Miocene of Burma. Structure and age of Tayngtha hills, Myingyan dis- trict, Upper Burma. Fossils from Sedimentary rocks of Oman (Arabia). Rubies in Kachin hills, Upper Burma. Cretaceous Orbitoides of India. Two Calcutta Earth- of 1906. Miscellaneous Notes. | Part 4.—Pseudo-Fucoids from Pab sandstones at Fort Munro, and from Vindhyan series. Jadeite in Kachin Hills, Upper Burma. Wetchok-Yedwet Pegu outcrop, Magwe dis- trict, Upper Burma. Group of manganates, comprising Hollandite, Psilomelane and Coronadite. Occurrence of Wolfram in Nagpur district, Central Provinces. Mis- cellaneous Notes. Index to Volume XXXVI. Vor. XXXVII, 1908-09. Part 1.—General report for 1907. Mineral Production of India during 1907. Striated boulders in the Blaini formation. | Part 2.—Tertiary and Post-Tertiary Freshwater Deposits of Baluchistan and Sind. Geo- logy and Minerals of Rajpipla. Suitability of Rajmahal sands for glass-making. Vredenburgite, Sitaparite and Juddite. Laterites from the Central Provinces. Mis- cellaneous notes. The price fixed for these publications is 1 rupee (1s. 4d.) each part or 2 rupews (2s. 8d.) each volume of four parts. 15 PUBLICATIONS. The publications of the Department include— PaLZonToLocia Inpica, arranged in series, and sold in parts which are priced at 4 annas (4 pence) per plate. Memoirs, Vols. I—XX XVI, including the larger papers on geological subjects. Recorps, Vols. {—XXXV1I, including the shorter papers and Annual Reports from — 1868 to 1908, sold in parts, price one rupee each. MANUALS, GUIDES AND Maps. A compiete list of the contents of these publications can be obtained by application to the Registrar, Geological Survey of India, 27, Chowringhee Road, Calcutta. Indexes te the Genera and Species described in the Paleontologia Indica up to 1891, to the "ig hii Vols. I—XX, and to the Records, Vols. I—X XX, have been printed for sale. GEOLOGICAL SURVEY OF INDIA. os Director. Siz THomas H. Hottanp, K.C.1.E., D.Sc., F.R.S., A.R.C.8., F.G.S. Superintendents. T. H. D. 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E. MacAvtay Avpstey, F.Z.S. Geological Museum, Library, and Office, Calcutta. in THE Pw yoRK ACAD 227 Ge Sai NCES. MEMOIRS | OF - THE GEOLOGICAL SURVEY OF INDIA. VOLUME XXXVII. THE MANGANESE-ORE Deposits oF INDIA, by L. LeicH FERMOR, A.R.S.M., B.Sc. (LONDON), F.G.S., Ass7stant Superintendent, Geological Survey of India. PART III: ECONOMICS AND MINING. Published by order of the Government of India. CALCUTTA : SOLD AT THE OFFICE OF THE GEOLOGICAL SURVEY, 27, CHOWRINGHEE ROAD.: LONDON : MESSRS. KEGAN PAUL, TRENCH, TRUBNER & CO. BERLIN : MESSRS. FRIEDLANDER UND SOHN. 1909. Brice : Parts 1, 2 and 3, Ro. 3 cach: Sart 4, Rs. 5; ot Ro. 8 per volume of 4 parto, MEMOIRS OF THE GEOLOGICAL SURVEY OF INDIA. Vou. VoL. Vot. Vou. Vou. Vou. Vot. Vou. Voy I. Pt. 1, 1856 (out of print) : Coal and Iron of Talchir.—Talchir Coal-field-— Gold-yielding deposits of Upper Assam.—Gold from Shué-gween. 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XXXV. Pt. 1, 1902 (price 2 Rs.) : Geology of Western Rajputana. Pt. 2, 1903 (price 1 Re.) : Aftershocks of Great Earthquake of 12th June 1897. Pt. 3, 1904 (price 1 Re.) : Seismic phenomena in British India and their connection with its Geology. Pt. 4 (in the Press) : Geolegy of Andaman Islands, with references to Nicobars. XXXVI. Pt. 1, 1904 (price 4 Rs.) : Geology of Spiti. Pt. 2, 1907 (price 3 Rs.) : Geology of Provinces of Tsang and U in Central Tibet. XXXVII. Manganese-Ore Deposits of India. Part 1 (price 3 Rs.) : Introduction and Mineralogy. Part 2 (price 3 Rs.): Geology. Part 3 (price 3 Rs.) : Economics and Mining. Part 4 (price 5 Rs.) : Description of Deposits (in the Press’. . XXXVIII. (In the Press) : Kangra Earthquake of 4th April 1905. 3 PALASONTOLOGIA INDICA, (Ser. I, III, V, VI, VIII.)—CRETACEOUS FAUNA OF SOUTHERN INDIA, by HF, SLOLICZKA, except Vou. I, Pt. 1, by H. F. BLANFORD. Ser. I & mee I. The Cephalopoda (1861-65), pp. 216, pls. 94 (6 double). V.—Vot. 11. ‘The Gastropoda (1867-68), pp. xiii, 500, sok aA V1.—Vot. 111. The Pelecypoda (1870-71), pp. xxii, 537, pls VIII.—Vot. IV. The Branchiopoda, Dibopede, Echinodermata, Cora etc. eit 73), PP- v, 202, pls. 2Y. (SER. II, XI, XII.)—THE FOSSIL FLORA OF THE GONDWANA SYSTEM, by O. FEISTMANTEL, except Vou. I, Pt. 1, by T. OLDHAM and J. MORRIS. Vou. I, pp. xviii, 233, pls. 72. 1863-79. Pt. 1; Rajmahal Group, Rajmahdal Hills, Pt. 2; Lhe same (continued). Pt. 3; Plants from Golapili. Pt. 4; Outliers on the Madras Coast. Vor. + Il; pp: xii; i pls. 26. 1876-78. Pt. 1; Jurassic Flora of Kach. Pt. 2; Flora of the Jabalpur Group. Vou. III, pp. xi, 644149, pls. 80 (9 double) (I—XXXI+IA—XLVIIA). 1879. SL. oPt.ws The Flora of the Talchir-Karharbari beds. Pt. 2; The Flora of the Damuda and Panchet Divisions. Pt. 3; The same (concluded). Vou. IV, pp. xxvi, 25+66, pls. 35 (2 double) (I-XXV+IA—XLVA). Ft. 1 (1882); Fossil Flora of the South Rewah Gondwana basin. Pt. 2 (1886); Fossil Flora of some of the coal-fields in Western Bengal. ~~ (Ser. IX.)—JURASSIC FAUNA OF KACH. Vou. I (1873-76). The Cephalopoda, by W. WaaGEN, pp. i, 244, pls. 60 (6 double). ut. II, pt. 1 (1893). The Echinoidea of Kach, by J. W. Grecory, pp. 12, pls. 2. Vou. II, pt. 2 (1900). The Corals, by J. W. Gregory, pp. 196, I—IX, pls. 26. Vou. III, pt. 1 (1900). The Brachiopoda, by F. L. Kircur, pp. 87, pls. 15. Vou. III, pt. 2 (1903). Lene ee ae Genus Trigonia, by F. Lc em pp. 122, pls. 1 < rS) —_ (Ser. IV.)—INDIAN PRE-TERTIARY VERTEBRATA. pp. vi, 137, pls. 26. 1865-85 Pt. 1 (1865); rae i es Fossils from the Panchet rocks, by T. H. Huxtey. Pt. 2 (1878); The Vertebrate Fossils VoL. — ? of the Kota- Malevi Gerue by Se P. pr M. Grey Egerton, L. C. Mratt, . and W. T. BrLanrorp. 3 (1879); Reptilia and Batrachia, by R. LypEKKER. Pt. 4 (1885); Phe Labyrinthodont from the Bijori group, by R. Lyprexxer. Pt. 5 (1885); The Reptilia and Amphibia of the Maleri and Denwa groups, by R. LypreKxKer. {Ser. X.) INDIAN TERTIARY AND POST-TERTIARY eae by RR. LYDEKKER, except Vou. I, Pr. 1, by R. B. FOOT Vor. I, pp. xxx, 300, pls. 50. 1874-80. Pt. 1; Rhinoceros eae Pt. 2; Molar tecth and other remains of Mammalia. Pt. 3; Crania of Ruminants. Pt. 4; Supplement to Pt. 3. Pt. 5; Siwalik and Narbada Proboscidia. 4 Vor. II, pp. xv, 363, pls. 45. 1881-84. Pt. 1; Siwalik Rhinocerotide. Pt. 2: Supple- j ment to Siwalik and Narbada Proboscidia. Pt 3; Siwalik and Narbada Equide. Pt. 4; Siwalik Camelopardalide. Pt. 6; Siwalik Selenodont ; Suina, etc. Pt. 6; Siwalik and Narbada Carnivora. Vou. ut, pp. xxiv, 264, pls. 38. 1884-86. Pt. 1; Additional Siwalik Perissodactyla ane Proboscidia. Pt. 2; Siwalik and Narbada Bunodont Suina. Pt. 3; Rodents and new Ruminants from the Siwaliks. Pt. 4; Siwalik Birds. Pt. 5; Mastodon Teeth from Perim Island. Pt. 6; Siwalik and Nar- bada Chelonia. Pt. 7; Siwalik Crocodilia, Lacertilia and Ophidia, Pt. 8; Tertiary Fishes. Vou. ‘ty, pt. 1 (1886). Siwalik Mammalia (Supplement 1), pp. 18, pls. 6. ~ VoL. IV, pt. 4 (1886). The Fauna of the Karnul caves : and addendum to pt. 1; pp. 49 (19—58), pls. 5 (vii—xi). Vor. IV, pt. 3, 10) Eocene Chenolia from the Salt-range; pp. 7 (59—65), pls. 2 (xii— xii). (Sen, VIL, XIV.)—TERTIARY AND UPPER CRETACEOUS FAUNA OF WESTERN a eOnte OTe MARTIN DUNCAN and W. PERCY SLADEN, except Pt. 1, by Vo. I, PP. 1641104382491 — 599, pls. 54+28+458+13=104. 1871—85. Pt. 1: Tertiary Crabs from nes and Kach. Pt. 1 (new 2): Sind Fossil Corals and Alcyonaria; by P. Martin Duncan. Pt. 3: The Fossil Echinoidea of Sind : Fas 1, The ‘Cardita beauwmonti beds; Fas. 2, The Ranikot Series in Western Sind; #'as. 3, ‘lhe Khirthar Series; Mas. 4, The Nari (Oligocene) Series ; Fas 5, The Gaj (Miocene) Series; Mas. 6, The Makran (Pliocene) Series ; by Duncan and Sladen. Pt. 4: The Fossil Kchinoidea of Kach and Kattywar; by Duncan, Sladen and Blanford, ; (Ser. XIII.)—SALT-RANGE FOSSILS, by WILLIAM WAAGEN, Pu.D. Productus-Limestone Group : Vou. I, pt. 1 (1879). Pisces, Cephalopoda, pp. 72, pls. 6. ante A b's », 2 (1880). Gastropoda and supplement to pt. 1, PP: Ba (73-183), pls. 10 (1 double), (vii— af eS oe eee (1881). Pelecypoda, pp. 144 (185—328), pls. 8 (xvil—xxiv). i oy ece $A », 4 (1882—85). Brachiopoda, pp. 442 (329—770), pls. 62 (xxv—Ixxxvi). a AA + 0 (1885). Bryozoa—Annelide—Kchinodermata, pp. 64 (771—834), pls. 10 (Ixxxvii—xcvi). af pe % », © (1886). Coelenterata, pp. 90 (835-924), pls. 20 (xcvil—cxvi). 35 Ss is ee Celenterata, Protozoa, pp. 74 (926— 998), pls. 12 (cxvii—exxviii). Fossils from the Ceratite Formation : Vol. II, pt. i (1885). Piscus—Ammonoidea, pp. 324, pls. 40. Geological Results : Vol. IV, pt. (1889), pp. 1—88, pls. 4. ay) ” ”» » 2 (18 91), pp. g9—242, pls. 8. (Ser. XV.)—HIMALAYAN FOSSILS. Upper-triassic and liassic faunz of the exotic blocks of Malla Johar in the Bhot Mahals of Kumaon : Vol. I, pt. I (1808), by Dr. C. Diener, pp. 100, pls. 16 (1 double). Anthracolithic Fossils of Kashmir and Spiti: Vol. I, pt. 2 (1899), by Dr. C. Diener, pp. 96, pls. 8. The Permocarboniferous Fauna of Chitichun No. I: Vol. I, pt. 3 (1897), by Dr. C. Diener, pp. 105, pls. 13. The Permian Fossils of the Productus Shales of Kumaon and Garhwal : Vol. I, pt. 4 (1897), y Dr. C. Diener, pp. 54, pls. 5. The Permian ioe of the ‘Gentes Himalayas : Vol. I, pt. 5 (1903), by Dr. C. Diener, pp. 204, p. 0. ¢ The Gephalopoda of the Lower Trias: Vol. II, pt. 1 (1897), by Dr. C. Diener, pp. 182, 23 pis The i. ata of the Muschelkalk : Vol. II, pt. 2 (1895), by Dr. C. Diener, pp. 118, 31 pest Triassic Cephalopoda Faune of the Himalaya: Vol. III, pt. 1 (1899), by Dr. E. von Mojsisovics, pp. 157, pls. 22. Trias Brachiopoda and Lamellibranchiata : Vol. III, pt. 2 (1899), by Alexander ‘Bittner, pp. 76, pls. 12 (2 double). The Fauna of the Spiti Shales: Vol. IV, pt. 1 (1903), by Dr. V. ee pp. 132, pls. 18. The Fauna of the Tropites-Limestone of Byans: Vol. V, Memoir No. 1 (1906), by Dr. C. Diener, pp. 201, pls. 17 (1 double). The Fauna of the Himalayan Muschelkalk : Vol. V, Memoir No. 2 (1907), by Dr. C. Diener, pp. 140, pls. 17 (2 double). Ladinic, Carnic and Noric faune of Spiti : Vel: V, Memoir No. 3 (1908), by Dr. C. Diener, pp. 157, pls. 24 (3 double). The Cambrian Fossils of Spiti : Vol. V, Memoir No. 4 (in the Press), by F. R. C. Reed. Lower triassic Cephalopoda from Spiti, Malla Johar and Byans: Vol. VI, Memoir No. 1 (in the Press), by Drs. A. von Krafft and C. Diener. The Fauna of the Traumatocrinus Limestone of Painkhanda: Vol. VI, Memoir No. 2 (in the Press), by Dr. C. Diener. x (Ser. XVI.)\—BALUCHISTAN FOSSILS, by FRITZ pirate ee? Pu.D., F.G.S. The Fauna of the Kellaways of Mazar Drik: Vol. I, pt. 1 (1895), pp. 22, pls. 13. The Fauna of the (Neocomian) Belemnite Beds: Vol. I, pt. 2 (1897), pp. 6, pls. 2. The Fauna of the Upper Cretaceous (Maéstrichtien) Beds of the Mari Hills : Vol. I, pt 3 (1897), pp. 79, pls. 23. (NEW SERIES.) The ee Fauna of the Eastern Salt-range : Vol. I, Memoir 1 (1899), K. Redlich, pp. 14, p Notes on the Morphology of the Pelecypoda: Vol. I, Memoir 2 (1899), Fritz Noetling, pp » Pls eee 2S pbs Miocene Beds of Burma: Vol. I, Memoir 3 (1901), Fritz Noetling, pp. 378, pls. 25. Observations sur quelques Plantes Fossiles des Lower Gondwanas: Vol. II, Memoir 1 (1902), R. Zeiller, pp. 39, nls. 7. Permo-Carboniferous (Lower Gondwana) Plants and Vertebrates from Kashmir: (1 Plants, by A. C. Seward; (2} Fishes and Labyrinthodonts, by A. Smith Woodward : Vol. II, Memoir No. 2 (1905), pp. 13, pls. 3. The Lower Palzozoic Fossils of the Northern Shan Pieler; Upper Burma : Vol. II, Memoir No. 3 (1906), by F. R. C. Reed, pp. 154, pls. 8. The Fauna of the Napeng Beds cr ‘the Rhetic Bede of Upper Burma: Vol. II, Memoir No. 4 (1908), by Miss M. Healey, pp. 88, pls. 9 The Devonian Faunas of the Northern Shan States : Vol. II, Mena No. 5 (1908), by F. R. C. Reed, pp. 183, pls. 20. The Mollusca of the Ranikot Series: Vol. III, Memoir No. 1 (in the Press), by M. Cossmann and G. Pissarro. On Some Fish-remains from the Beds at pop aes peor Provinces : Vol. III, i No. 3 (1908), by A. Smith Woodward, pp. 6, pl. » Meni The price fixed for these publications is four annas ( 4 pence ingl ; minimum charge of Re. 1 ) per single plate, with a RECORDS OF THE GEOLOGICAL SURVEY OF INDIA. Vou. I, 1868. Part 1 (out of print).—Annual report for 1867. Coal-seams of Tawa valley. Coal in Garrow Hills. Copper in Bundelkhand. Meteorites. 4 Part 2 (out of print).—Coal-seams of neighbourhood of Chanda. Coal near Nagpur. Geo- logical notes on Surat collectorate. Cephalopodous fauna of South Indian cretaceous deposits. Lead in Raipur district. Coal in Kastern Hemisphere. Meteorites. Part 3 (out of print).—Gastropodous fauna of South Indian cretaceous deposits. Notes on route from Poona to Nagpur vid Ahmednuggur, Jalna, Loonar, Yeotmahal, Mangali, and Hingunghat. Agate-tlake in pliocene (7%) deposits of Upper Godavery. Boundary of Vindhyan series in Rajputana. Meteorites. Vou. II, 1869. Part 1 (out of print).—Valley of Poorna river, West Berar. Kuddapah and Kurnool formations. Geological sketch of Shillong plateau. Gold in Singhboom, etc. Wells at Hazareebagh. Meteorites. ¥ Part 2.—Annual report for 1868. Pangshura tecta and other species of Chelonia from newer tertiary deposits of Nerbudda valley. Metamorphic rocks of Bengal. ‘ Part Be gooey of Kuch, Western India. Geology and physical geography of Nicobar Islands. Part 4.—Beds containing silicified wood in Eastern Prome, British Burma. Mineralogical statistics of Kumaon division. Coal-field near Chanda. Lead in Raipur district. Meteorites. Vou. III, 1870. Part 1.—Annual report for 1869. Geology of neighbourhood of Madras. Alluvial deposits of Irrawadi, contrasted with those of Ganges. Part 2 (out of print).—Geology of Gwalior and vicinity. Slates at Chiteli, Kumaon. Lead vein near Chicholi, Raipur district. Wardha river coal-fields, Berar and Cen- tral Provinces. Coal at Karba in Bilaspur district. Part 3 (out of print)—Mohpani coal-field. Lead-ore at Slimanabad, Jabalpur district. Coal east of Chhatisgarh between Bilaspur and Ranchi. Petroleum in Burma. Petro- leum locality of Sudkal, near Futtijung, west of Kawalpindi. Argentiferous galena and copper in Manbhum. Assays of iron ores. Part 4 (out of print).—Geology of Mount ‘lilla, Punjab. Copper deposits of Dalbhum and Singbhum : 1.—Copper mines of Singbhum : 2.—Copper of Dalbhum and Sing- bhum. Meteorites. Vou. IV, 1871. — Part 1.—Annual report for 1870. Alleged discovery of coal near Gooty, and of indications of coal in Cuddapah district. Mineral statistics of Kumaon division. Part 2.—Axial grcap in Western Prome. Geological structure of Southern Konkar. Supposed occurrence of native antimony in the Straits Settlements. Deposit in boilers of steam-engines at Raniganj. Plant-bearing sandstones of Godavari valley, on south- ern extensions of Kamthi group to neighbourhood of Ellore and Rajamandri, and on possible occurrence of coal in same direction. Part 3.—Borings for coal in Godavari valley near Dumagudem and Bhadrachalam. Narbada coal-basin. Geology of Central Provinces. Plant-bearing sandstones of Godavari valley. Part 4.—Ammonite fauna of Kutch. HKaigur and Hengir (Gangpur) Coal-field. Sandstones Vee ee of first barrier on Godavari, and in country between Godavari and ore. , Vou. V, 1872. Part 1.—Annual report for 1871. Relations of rocks near Murree (Mari), Punjab. Mineral- ogical notes on gneiss of South Mirzapur and adjoining country. Sandstones in A anal of first barrier on Godavari, and in country between Godavari and ore. x 7 Part 2.—Coasts of Baluchistan and Persia from Karachi to head of Persian Gulf, and some of Gulf Islands. Parts of Kummummet and Hanamconda districts in Nizam’s Dominions. Geology of Orissa. New coal-field in south-eastern Hyderabad (Deccan) territory. ; Part 3.—Maskat and Massandim on east coast of Arabia. Example of local jointing. Axial group of Western Prome. Geology of Bombay Presidency. Part 4.—Coal in northern region of Satpura basin. Evidence afforded by raised oyster banks on coasts of India, in estimating amount of elevation indicated thereby. Possible field of coal-measures in Godavari district, Madras Presidency. Lameta or intra-trappean formation of Central India. Petroleum localities in Pegu. Supposed eozoonal limestone of Yellam Bile. Vou. VI, 1873. Part 1.—Annual report for 1872. Geology of North-West Provinces. Part 2.—Bisrampur coal-field. Mineralogical notes on gneiss of South Mirzapur and ad- joining country. Part 3.—Celt in ossiferous deposits of Narbada valley (Pliocene of Falconer) : on age of deposits, and on associated shells. Barakars (coal-measures) in Beddadanole field, Sa district. Geology of parts of Upper Punjab. Coal in India. Salt-springs of Pegu. Part 4.—Iron deposits of Chanda (Central Provinces). Barren Islands and Narkondam. Metalliferous resources of British Burma. Vout. VII, 1874. Part 1 (out of print).—Annual report for 1873. Hill ranges between Indus valley in Ladak and Shah-i-Dula on frontier of Yarkand territory. Iron ores of Kumaon. Raw materials for iron-smelting in Raniganj field. Elastic sandstone, or so-called Itaco- lumyte. Geological notes on part of Northern Hazaribagh. : Part 2 (out of print).—Geological notes on route traversed by Yarkand Embassy from Shah-i-Dula to Yarkand and Kashgar. Jade in Karakas valley, ‘lurkistan. Notes from Eastern Himalaya. Petroleum in Assam. Coal in Garo Hills. Copper in Narbada valley. Potash-sa)+ from East India. Geology of neighbourhood of Mari hill station in Punjab. Part $.—Geological observations made on a visit to Chaderkul, Thian Shan range. Former extension of glaciers-within Kangra district. Building and ornamental stones of India. Materials for iron manufacture in Raniganj coal-field. Manganese-ore in Wardha coal-field. Part 4 (out of print).—Auriferous rocks of Dhambal hills, Dharwar district. Antiquity of human race in India. Coal recently discovered in the country of Luni Pathans, south-east corner of Afghanistan. Progress of geological investigation in Godavari district, Madras Presidency. Subsidiary materials for artificial fuel. Vox. VIII, 1875. Part 1.—Annual report for 1874. The Altum-Artush considered from geological point of view. Evidences of ‘ ground-ice’ in tropical India, during Talchir period. Trials of Raniganj fire-bricks. : Part 2 (out of print).—Gold-fields of south-east Wynaad, Madras Presidency. Geological notes on Khareean hills in Upper Punjab. Water-becring strata of Surat district. Geology of Scindia’s territories. ; Part 3 (out of print).—Shahpur coal-field, with notice of coal explorations in Narbada region. Coal.recently found near Moflong, Khasia Hills. Part 4 {out of print).—Geology of Nepal. Raigarh and Hingir coal-fields. Vou. IX, 1876. Part 1 (out of print).—Annual report for 1875. Geology of Sind. Part 2.—Retirement of Dr. Oldham. Age of some fossil floras in India. Cranium of Stegodon Ganesa, with notes on sub-genus and allied forms. Sub-Himalayan series in Jamu (Jammoo) Hills. Part 3.—¥Fossil floras in India. Geological age of certain groups comprised in Gendwana series of India, and on evidence they afford of distinct zoological and botanical terres- trial regions in ancient epochs. Relations of fossiliferous strata at Maleri and Kota, near Sironcha, C. P. Fossil mammalian faunz of India and Burma. Part j.—¥ossil floras in India. Osteology of Merycopotamus dissimilis. Addenda and Corrigenda to paper on tertiary mammalia. Plesiosaurus in India. Geology of Pir Panjal and neighbouring districts. - 8 a & ad "-» Von. X, 1877. Part 1.—Annual report for 1876. Geological notes on Great Indian Desert between Sind and Rajputana. Cretaceous genus Omphalia near Nameho lake, Tibet, about 75 miles north of Lhassa. Estheria in Gondwana formation. Vertebrata from Indian tertiary and secondary rocks. New Emydine from the upper tertiaries of Northern Punjab. Observations on under-ground temperature. Part 2.—Rocks of the Lower Godavari. ‘ Atgarh Sandstones’ near Cuttack. Fossil floras in India. New or rare mammals from the Siwaliks. Arvali series in North-eastern Rajputana. Borings for coal in India. Geology of India. Part $.—Tertiary zone and underlying rocks in North-west Punjab. Fossil floras in India. Erratics in Potwar. Coal explorations in Darjiling district. Limestones in neighbour- hood of Barakar. Forms of blowing-machine used by smiths of Upper Assam. Analyses of Raniganj coals. = Part 4.—Geology of Mahanadi basin and its vicinity. Diamonds, gold, and lead ores of Sambalpur district. ‘Eryon Comp. Barrovensis,’ McCoy, from Sripermatur group near Madras. Fossil floras in India. The Blaini group and ‘Central Gneiss’ in Simla Himalayas. Tertiaries of North-West Punjab. Genera Cheromeryx snd Rhagatherium. Vou. XI, 1878. Part 1.—Annual report for 1877. Geology of Upper Godavari basin, between_river Wardha and Godavari, near Sironcha. Geology of Kashmir, Kishtwar, and Pangi. Siwalik mammals. Palzontological relations of Gondwana system. ‘Erratics in Punjab.’ Part 2.—Geology of Sind (second notice). Origin of Kumaun lakes. Trip over Milam Pass, Kumaun. Mud volcanoes of Ramri and Cheduba. Mineral resources of Ramri, Cheduba and adjacent islands. Part $.—Gold industry in Wynaad. Upper Gondwana series in Trichinopoly and Nellore- Kistna districts. Senarmontite from Sarawak. Part 4.—Geographical distribution of fossil organisms in India. Submerged forest on Bombay Island. Vou. XII, 1879. Part 1.—Annual report for 1878. Geology of Kashmir (third notice). Siwalik mammalia. Siwalik birds. Tour through Hangrang and Spiti. Mud eruption in Ramri Island (Arakan). Braunite, with Rhodonite, from Nagpur, Central Provinces. Palzontologi- cal notes from Satpura coal-basin. Coal importations into India. Part 2.—Mohpani coal-field. Pyrolusite with Psilomelane at Gosalpur, Jabalpur district. Geological reconnaissance from Indus at Kushalgarh to Kurram at Thal on Afghan frontier. Geology of Upper Punjab. . Part $.—Geological features of northern Madura, Pudukota State, and southern parts of Tanjore and Trichinopoly districts included within limits of sheet 80 of Indian Atlas. Cretaceous fossils from Trichinopoly district, collected in 1877-78. Sphenophyllum and other Equisetacee with reference to Indian form Trizygia Speciosa, Royle (Spheno- phyllum Trizygia, Ung.). Mysorin and Atacamite from Nellore district. Corundum from Khasi Hills. Joga neighbourhood and old mines on Nerbudda. Part 4.—‘ Attock Slates’ and their probable geological position. Marginal bone of unde- scribed tortoise, from Upper Siwaliks, near Nila, in Potwar, Punjab. Geology of North Arcot district. Road section from Murree to Abbottabad. Vor. XIII, 1880. Part 1.—Annual report for 1879. Geology of Upper Godavari basin in neighbourhood of Sironcha. Geology of Ladak and neighbouring districts. Teeth of foseil fishes fica Ramri Island and Punjab. Fossil genera Néggerathia, Stbg., Noggerathiopsis, Fstm., pe ee < ork remengg Roky secondary rocks of Europe, Asia, and ustralia. Foss ants from tt : sh Budin, irgujah. i i : of eruption in Ko p ; attywar e udin, and Sirgujah. Volanic foci ‘art 2.—Geological notes. Palzontological notes on lower trias of Himalayas. Artesi wells at Pondicherry, and possibility of finding sources of water-supply dee Part 3.—Kumaun lakes. Celt of palzolithic type in Punjab. Palzontological notes from Karharbari and South Rewa coal-fields. Correlation of Gondwana flors with other floras. Artesian wells at Pondicherry. Salt in Rajputana. Gas and mud eruptions on Arakan coast on 12th March 1879 and in June 1845, 9 Part 4.—Pleistocene deposits of Northern Punjab, and evid@hce they afford of*extreme climate during portion of that period. Useful minerals of Arvali region. Correlation of Gondwana flora with that of Australian coal-bearing system. Reh or alkali soils and saline well waters. Reh soils of Upper India. Naini Tal landslip, 18th Septem- . ber 1880. Vout. XIV, 1881. Part 1.—Annual report for 1880. Geology of part of Dardistan, Baltistan, and neighbour- ing districts. Siwalik carnivora. Siwalik group of Sub-Himalayan region. South Rewah Gondwana basin. Ferruginous beds associated with basaltic rocks of north- eastern Ulster, in relation to Indian laterite. Rajmahal plants. Travelled blocks of the Punjab. Appendix to ‘ Paleontological notes on lower trias of Himalayas.” Mam. malian fossils from Perim Island. Part 2.—Nahan-Siwalik unconformity in North-Western Himalaya. Gondwana _ verte- brates. Ossiferous beds of Hundes in Tibet. Mining records and mining record office of Great Britain; and Coal and Metalliferous Mines Act of 1872 (England). Cobaltite and danaite from Khetri mines, Rajputana; with remarks on Jaipurite (Syepoorite). Zinc-ore (Smithsonite and Blende) with barytes in Karnul district, Madras. Mud eruption in island of Cheduba. ; Part 3.—Artesian borings in India. Oligoclase granite at Wangtu on Sutlej, North-West Himalayas. Fish-palate from Siwaliks. Paleontological notes from Hazaribagh and Lohardagga districts. Fossil carnivora from Siwalik hills. Part 4.—Unification of geological nomenclature and cartography. Geology of Arvali region, central and eastern. Native antimony obtained at Pulo Obin, near Singapore. Tur- gite from Juggiapett, Kistnah district, and zine carbonate from Karnul, Madras. Section from Dalhousie to Pangi, vid Sach Pass. South Rewah Gondwana basin. Submerged forest on Bombay Island. s Vou. XV, 1882. Part 1.—Annual report for 1881. Geology of North-West Kashmir and Khagan. Gend- wana labyrinthodonts. Siwalik and Jamna mammals. Geology of Dalhousie, North- West Himalaya. Palm leaves from (tertiary) Murree and Kasauli beds in India. Iridosmine from Noa-Dihing river, Upper Assam, and Platinum from Chutia Nagpur. On (1) copper mine near Yongri hill, Darjiling district; (2) arsenical pyrites in same neighbourhood; (3) kaolin at Darjiling. Analyses of coal and fire-clay from Makum coal-field, Upper Assam. Experiments on coal of Pind Dadun Khan, Salt-range, with reference to production of gas, made April 29th, 1881. Proceedings of International Congress of Bologna. Part 2.—Geology of Travancore State. Warkilli beds and reported associated deposits at Quilon, in Travancore. Siwalik and Narbada fossils. Coal-bearing rocks of Upper Rer and Mand rivers in Western Chutia Nagpur. Pench river coal-field in Chhind- wara district, Central Provinces. Bovings for coal at Engsein, British Burma. Sap- phires in North-Western Himalaya. Eruption of mud volcanoes in Cheduba. Part 3.—Coal of Mach (Much) in Bolan Pass, and of Sharigh on Harnai route between Sibi and Quetta. Crystals of stilbite from Western Ghats, Bombay. Traps of Darang and Mandi in North-Western Himalayas. Connexion between Hazara and Kashmir series. Umaria coal-field (South Rewah Gondwana basin). Daranggiri coal-field, Garo Hills, Assam. Coal in Myanoung division, Henzada district. Part 4 (out of print).—Gold-fields of Mysore. Borings for coal at Beddadanol, Godavari district, in 1874. Supposed occurrence of coal on Kistna. Vout. XVI, 1883. Part 7.—Annual report for 1882. Richthofenia, Kays (Anomia Lawrenciana, Koninck). Geology of South Travancore. Geology of Chamba. Basalts of Bombay. Part 2.—Synopsis of fossil vertebrata of India. Bijori Labyrinthodont. Skuli of Hippo- therium antilopinum. Iron ores, and subsidiary materials for manufacture of iron, in north-eastern part of Jabalpur district. Laterite and other manganese-ore occurring at Gosulpore, Jabalpur district. Umaria coal-field. Part 3.—Microscopic structure of some Dalhousie rocks. Lavas of Aden. Probable occur- rence of Siwalik strata in China and Japan. Mastodon angustidens in India. Traverse between Almora and Mussooree. Cretaceous coal-measures at Borsora, in Khasia Hills, near Laour, in Sylhet, 10 Part 4.—Palzontological notes from Daltonganj and Hutar coal-fields in Chota Nagpur. Altered basalts of Dalhousie region in North-Western Himalayas. Microscopic struc- ture of some Sub-Himalayan rocks of tertiary age. Geology of Jaunsar and Lower Himalayas. Traverse through Eastern Khasia, Jaintia, and North Cachar Hills. Native lead from Maulmain and chromite from the Andaman Islands. Fiery eruption from one of mud volcanoes of Cheduba Island, Arakan. Irrigation from wells in North-Western Provinces and Oudh. “ Vou. XVII, 1884. Part 1.—Annual report for 1883. Smooth-water anchorages or mud-banks of Narrakal and Alleppy on Travancore coast. Billa Surgam and other caves in Kurnool district. Geology of Chuari and Sihunta parganas of Chamba. Lyttonia, Waagen, in Kuling series of Kashmir. Part 2.—Earthquake of 31st December 1881 Microscopic structure of some Himalayan granites and gneissose granites. Choi coal exploration. Re-discovery of fossils in Siwalik beds. Mineral resources of the Andaman Islands in neighbourhood of Port Blair. Intertrappean beds in Deccan and Laramie group in Western North America. Part 3 (out of print).—Microscopic structure of some Arvali rocks. Section along Indus from Peshawar Valley to Salt-range. Sites for boring in Raigarh-Hingir coal-field (first notice). Lignite near Raipore, Central Provinces. Turquoise mines of Nishapiar, Khorassan. Fiery eruption from Minbyin mud volcano of Cheduba Island, Arakan. Langrin coal-field, South-Western Khasia Hills. Umaria coal-field. Part 4.—Geology of part of Gangasulan pargana of British Garhwal. Slates and schists imbedded in gneissose granite of North-West Himalayas. Geology of Takht-i-Sulei- man. Smooth-water anchorages of Travancore coast. Auriferous sands of the Suban- siri river.~ Pondicherry lignite, and phosphatic rocks at Musuri. Billa Surgam caves. Vou. XVIII, 1885. Part 1.—Annual report for 1884. Country between Singareni coal-field and Kistna river. Geological sketch of country between Singareni coal-field and Hyderabad. Coal and limestone in Doigrung river near Golaghat, Assam. Homotaxis, as illustrated from Indian formations. Afghan field notes. Part 2.—Fossiliferous series in Lower Himalaya, Garhwal. Age of Mandhali series in Lower Himalaya. Siwalik camel (Camelus Antiquus, nobis ex Fale. and Caut. MS.). Geology of Chamba. Probability of obtaining water by means of artesian wells in plains of Upper India. Artesian sources in plains of Upper India. Geology of Aka Hills. Alleged tendency of Arakan mud volcanoes to burst into eruption most frequently during rains. Analyses of phosphatic nodules and rock from Mussooree. Part 3.—Geology of Andaman Islands. Third species of Merycopotamus. Percolation as affected by current. Pirthalla and Chandpur meteorites. Oil-wells and coal in Thayetmyo district, British Burma. Antimony deposits in Maulman district. Kash- mir earthquake of 30th May 1885. Bengal earthquake of 14th July 1885. Part 4.—Geological work in Chhattisgarh division of Central Provinces. -Bengal earth- quake of 14th July 1885. Kashmir earthquake of 30th May 1885. Excavations in Billa Surgam caves. Nepaulite. Sabetmahet meteorite. Vor. XIX, 1886. Part 1.—Annual report for 1885. International Geological Congress of Berlin. Paleozoic Fossils in Olive group of Salt-raage. Correlation of Indian and Australian coal- bearing beds. Afghan and Persian Field-notes. Section from Simla to Wangtu, and petrological character of Amphibolites and Quartz Diorites of Sutlej valley. ‘ Part 2.—Geology of parts of Bellary and Anantapur districts. Geology of Upper Dehing basin in Singpho Hills. Microscopic characters of eruptive rocks from Central Hima- layas. Mammalia of Karnul Caves. Prospects of oe coal in Western Rajputana. Olive group of Salt-range. Boulder-beds of Salt-range. Gondwana Homotaxis. Part F sedlecionl sketch of Vizagapatam district, Madras. Geology of Northern Jesal- mer. Microscopic structure of Malaini rocks of Arvali region. Malanjkhandi copper- ore in Balaghat district, C. P. _ ; ; ae ‘ Part j.—Petroleum in India. Petroleum exploration at Khatan. Boring in Chhattisgarh coal-fields. Field-notes from Afghanistan: No. 3, Turkistan. Fiery eruption from one of mud volcanoes of Cheduba Island, Arakan. . Nammianthal aerolite. Analysis of gold dust from Meza valley, Upper Burma. i] , Vou. XX, 1887. Part 1.—Annual report for 1886. Field-notes from Afghanistan: No. 4, from Turkistan to India. Physical geology of West British Garhwal; with notes on a route traversed through Jaunsar-Bawar and Tiri-Garhwal. Geology of Garo Hills. Indian image- stones. Soundings recently taken off Barren Island and Narcondam. Talchir boulder- beds. Analysis of khosphatic Nodules from Salt-range, Punjab. Part 2.—Fossil vertebrata of India. Echinoidea of cretaceous series of Lower Narbada Valley. Field-notes : No. 5—to accompany geological sketch map of Afghanistan and North-Eastern Khorassan. Microscopic structure of Rajmahal and Deccan traps. Dolerite of Chor. Identity of Olive series in east with speckled sandstone in west of Salt-range in Punjab. Part 3.—Retirement of Mr. Medlicott. J. B. Mushketoff’s Geology of Russian Turkistan. Crystalline and metamorphic rocks of Lower Himalaya, Cackeal; and Kumaun, Sec- tion I. Geology of Simla and Jutogh. ‘ Lalitpur ’ meteorite. Part_4.—Points in Himalayan geology. Crystalline and metamorphic rocks of Lower Himalaya, Garhwal, and Kumaun, Section II. Iron industry of western portion of Raipur. Notes on Upper Burma. Boring exploration in Chhattisgarh coal-fields. (Second notice). Pressure Metamorphism, with reference to foliation of Himalayan Gneissose Granite. Papers on Himalayan Geology and Microscopic Petrology. Vor. XXI, 1888. Part 1.—Annual report for 1887. Crystalline and metamorphic rocks of Lower Himalaya, Garhwal, and Kumaun, Section III. Birds’-nest of Elephant Island, Mergui Archi- pelago. Exploration of Jessalmer, with a view to discovery of coal. . Facetted pebble from boulder bed (‘speckled sandstone’) of Mount Chel in Salt-range, Punjab. Nodular stones obtained off Colombo. Part 2.—Award of Wollaston Gold Medal, Geological Society of London, 1888. Dharwar System in South India. Igneous rocks of Raipur and Balaghat, Central Provinces. Sangar Marg and Mehowgale coal-fields, Kashmir. Part 3.—Manganese Iron and Manganese Ores of Jabalpur. ‘ The Carboniferous Glacial Period.’ Pre-tertiary sedimentary formations of Simla region of Lower Himalayas. Part 4.—Indian fossil vertebrates. Geology of North-West Himalayas. Blown-sand rock sculpture. Nummulites in Zanskar. Mica traps from Barakar and Raniganj- Vout. XXII, 1889. Part 1.—Annual report for 1888. Dharwar System in South India. Wajra Karur diamonds, and M. Chaper’s alleged discovery of diamonds in pegmatite. Generic posi- - tion of so-called Plesiosaurus Indicus. Flexible sandstone or Itacolumite, its nature, mode of occurrence in India, and cause of its flexibility. Siwalik and Narbada Chelonia. Part 2.—Indian Steatite. Distorted pebbles in Siwalik conglomerate. ‘ Carboniferous Glacial Period.’ Oil-fields of Twingoung and Beme, Burma. Gypsum of Nehal Nadi, Kumaun. Materials for pottery in neighbourhood of Jabalpur and Umaria. Part 3.—Coal outcrops in Sharigh Valley, Baluchistan. Trilobites in Neobolus beds of Salt-range. Geological notes. Cherra Poonjee coal-field, in Khasia Hills. Cobalti- ferous Matt from Nepal. President of Geological Society of London on International Geological Congress of 1888. Tin-mining in Mergui district. Part 4.—WLand-tortoises of Siwaliks. Pelvis of a ruminant from Siwaliks. Assays from Sambhar Salt-Lake in Rajputana. Manganiferous iron and Manganese Ores of Jabal- pur. Palagonite-bearing traps of Rajmahal hills and Deccan. Tin-smelting in Mala: Peninsula. Provisional*Index of Local Distribution of Important Minerals, Miscel- laneous Minerals, Gem Stones and Quarry Stones in Indian Empire. Part 1. Vou. XXIII, 1890. Part 1.—Annual report for 1889. Lakadong coal-fields, Jaintia Hills. Pectoral and pelvic irdles and skull of Indian Dicynodonts. Vertebrate remains from Nagpur district with description of fish-skull). Crystalline and metamorphic rocks of Lower Hima- layas, Garhwdl and Kumaun, Section IV. Vivalves of Olive-group, Salt-range. Mud-banks of Travancore coasts. . Part 2.—Petroleum explorations in Harnai district, Baluchistan. Sapphire Mines of Kashmir. Supposed Matrix of Diamond at Wajra Karur, Madras. Sonapet Gold- field. Field notes from Shan Hills (Upper Burma). New species of Syringospheride. 12 Part 3.—Geology and Economic Resources of Country adjoining Sind-Pishin Railway between Sharigh and Spintangi, and of country between it and Khattan. Journey through India in 1888-89, by Dr. Johannes Walther. Coal-fields of Lairungao, Mao- sandram, and Mao-belar-kar, in the Khasi Hills. Indian Steatite. Provisional Index of Local Distribution of Important Minerals, Miscellaneous Minerals, Gem Stones, and Quarry Stones in Indian Empire. ; : A Part 4.—Geological sketch of Naini Tal; with remarks on natural conditions governing mountain slopes. Fossil Indian Bird Bones. Darjiling Coal between Lisu and Ramthi rivers. Basic Eruptive Rocks of Kadapah Area. Deep Boring at Lucknow. Coal Seam of Dore Ravine, Hazara. Vor. XXIV, 1891. Part 1.—Annual report for 1890. Geology of Salt-range of Punjab, with re-considered theory of Origin and Age of Salt-Mart. Graphite in decomposed Gneiss (Laterite) in Ceylon. Glaciers of Kabru, Pandim, etc. Salts of Sambhar Lake in Rajputana, and ‘Reh’ from Aligarh in North-Western Provinces. Analysis of Dolomite from Salt- range, Punjab. Part 2.—Oil near Moghal Kot, in Sherdni country, Suleiman Hills. Mineral Oil from Suleiman Hills. Geology of Lushai Hills. Coal-fields in Northern Shan States. Reported Namséka Ruby-mine in Mainglén State. Tourmaline (Schorl) Mines in Mainglén State. Salt-spring near Bawgyo, Thibaw State. Part 3.—Boring in Daltongunj Coal-field, Palamow. Death of Dr. P. Martin Duncan. Pyroxenic varieties of Gneiss and Scapolite-bearing Rocks. Part 4.—Mammalian Bones from Mongolia. Darjiling Coal Exploration. Geology and Mineral Resources of Sikkim. Rocks from the Salt-range, Punjab. Von. XXV, 1892. Part 1.—Annual report for 1891. Geology of Thal Chotidli and part of Mari country. Petrological Notes on Boulder-bed of Salt-range, Punjab. Sub-recent and Recent Deposits of valley plains of Quetta, Pishin, and Dasht-i-Bedaolat; with appendices on Chamans of Quetta; and Artesian water-supply of Quetta and Pishin. Part 2 (out of print).—Geology of Saféd Koh. Jherria Coal-field. Part 3.—Locality of Indian Tscheffkinite. Geological Sketch of country north of Bhamo. Economic resources of Amber and Jade mines area in Upper Burma. lIron-ores and Tron Industries of Salem District. Riebeckite in India. Coal on Great Tenasserim . River, Lower Burma. Part 4.—Oil Springs at Moghal Kot in Shirani Hills. Mineral Oil from Suleiman Hills. New Amber-like Resin in Burma. Triassic Deposits of Salt-range. Vor. XXVI, 1893. Part 1.—Annual report for 1892. Central Himalayas. Jadeite in Upper Burma. Bur- mite, new Fossil Resin from Upper Burma. Prospecting Operations, Mergui District, 891-92. Part 2.—Earthquake in Baluchistan on 20th December 1892. Burmite, new amber-like fossil resin from Upper Burma. Alluvial deposits and Subterranean water-supply of Rangoon. Part 3.—Geology of Sherani Hills. Carboniferous Fossils from Tenasserim. Boring at Chandernagore. Granite in Tavoy and Mergui. Part 4.—Geology of country between Chappar Rift and Harnai in Baluchistan. Geology ' of part of Tenasserim Valley with special reference to Tendau-Kamapying Coal-field. Magnetite containing Manganese and Alumina. Hislopite. Vout. XXVII, 1894. Part 1.—Annual report for 1893. Bhaganwala Coal-field, Salt-range, Punjab. Part 2.—Petroleum from Burma. Singareni Coal-field, Hyderabad (Deccan). Gohna Landslip, Garhwal. Part $.—Cambrian Formation of Eastern Salt-range. Giridih (Karharbari) Coal-fields. Chipped (?},Flints in Upper Miocene of Burma. Velates Schmideliana, Chemn., and Provelates grandis, Sow. sp., in Tertiary Formation of India and Burma. Part 4.—Geology of Wuntho in Upper Burma. Echinoids from Upper Cretaceous System of Baluchistan. Highly Phosphatic Mica Peridotites intrusive in Lower Gondwana Rocks of Bengal. Mica-Hypersthene-Hornblende-Peridotite in Bengal. Vor. XXVIII, 1895. ; Part 1.—Annual report for 1894. Cretaceous Formation of Pondicherry. Early allusion to Barren Island. Bibliography of Barren Island and Narcondam from 1884 to 1894. 13 Part 2.—Cretaceous Rocks of Southern India and geographical conditions during later cretaceous times. Experimental Boring for Petroleum at Sukkur from October 1893. to March 1895, Tertiary system in Burma. Part 3.—Jadeite and other rocks, from Tammaw in Upper Burma. Geology nf Tochi Valley. Lower Gondwanas in Argentina. Part 4.—Igneous Rocks of Giridih (Kurhurbaree) Coal-field and their Contact Effects. Vindhyan system south of Sone and their relation to so-called Lower Vindhyans. Lower Vindhyan area of Sone Valley. Tertiary system in Burma. Vor. XXIX, 1896. Part 1.—Annual report for 1895. Acicular inclusions in Indian Garnets. Origin and Growth of Garnets and of their Micropegmatitic intergrowths in Pyroxenic rocks. Part 2.—Ultra-basic rocks and deiived minerals of Chalk (Magnesite) hills, and other localities near Salem, Madras. Corundum localities in Salem and Coimbatore districts, Madras. Corundum and Kyanite in Manbhum district, Bengal. Ancient Geography of ‘‘Gondwanaland.” Notes. Part 3.—Igneous Rocks from the Tochi Valley. Notes. Part 4.—Steatite mines, Minbu district, Burma. Lower Vindhyan (Sub-Kaimur) area of Sone Valley, Rewah. Notes. Vout. XXX, 1897. r Part 1.—Annual report for 1896. Norite and associated Basic Dykes and Lava-flows in Southern India. Genus Vertebraria. On Glossopteris and Vertebraria. Part 2.—Cretaceous Deposits of Pondicherri. Notes. Part 3.—Flow structure in igneous dyke. Olivine-norite dykes at Coonoor. Excavations. for corundum near Palakod, Salem District. Occurrence of coal at Palana in Bikanir. - Geological specimens collected by, Afghan-Baluch Boundary Commission of 1896. Part 4.—Nemalite from Afghanistan. Quartz-barytes rock in Salem District, Madras Presidency. Worn femur of Hippopotamus irravadicus, Caut. and Falc., from Lower : Pliocene of Burma. Supposed coal at Jaintia, Baxa Duars. Percussion Figures on ‘4 micas. Notes. : : Vou. XXXI, 1904. ; Part 1 (out of print).—Prefatory Notice. Copper-ore near Komai, Darjeeling district. Zewan beds in Vihi district, Kashmir. Coal deposits of Isa Khel, Mianwali district, : Punjab. Um-Rileng coal-beds, Assam. Sapphirine-bearing rock from Vizagapatam q district. Miscellaneous Notes. Assays. Part 2 (out of print).—Lt.-Genl. C. A. McMahon. Cyclobus Haydeni Diener. Auriferous- Occurrences of Chota Nagpur, Bengal. On the feasibility of introducing modern methods of Coke-making at East Indian Railway Collieries, with supplementary note- hy Director, Geological Survey of India. Miscellaneous Notes. Part 3 (out of print).—Upper Palzozoic formations of Eurasia. * Glaciation and History of Sind Valley. Halorites in Trias of Baluchistan. Geology and Mineral Resources: of Mayurbhanj. Miscellaneous Notes. : Part 4 (out of print).—Geology of Upper Assam. Auriferous Occurrences of Assam. Curious occurrence of Scapolite from Madras Presidency. Miscellaneous Notes. Index. Vou. XXXII, 1905. Part 1 (out of print).—Review of Mineral Production of India during 1898—1903. Part 2 (out of print).—General report, April 1903 to December 1904. Geoiogy of Pro- vinces of Tsang and U in Tibet. Bauxite in India. Miscellaneous Notes. Part 3 (out of print).—Anthracolithic Fauna from Subansri Gorge, Assam. Elephas- Antiquus (Namadicus) in Godavari Alluvium. Triassic Fauna of Tropites-Limestone of Byans. Amblygonite in Kashmir. Miscellaneous Notes. Part 4.—Obituary notices of H. B. Medlicott and W. T. Blanford. Kangra Earthquake- of 4th April 1905. Index to Volume XXXII. ; Vou. XXXITI, 1906. : ae # Part 1 (out of print).-—Mineral Production of India during 1904. Ploistogtne Movementtin Indian Peninsula. Recent Changes in Course of Nam-tu River, Northern Shan Statés. Natural Bridge in Gokteik Gorge. Geology and Mineral Resources of Narnaul D: trict (Patiala State). Miscellaneous Notes. ; j Part 2 (out of print).—General report for 1905. Lashio Coal-field, Northern Shan State Namma, Mansang and Man-se-le Coal-fields, Northern Shan States, Burma Mis cellaneous Notes. 14 Part 3.—Petrology and Manganese-Ore Deposits of Sausar Tahsil, Chhindwara district, Central Provinces. Geology of parts of valley of Kanhan River in Nagpur and Chhindwara districts, Central Provinces. Manganite from Sandur Hills. Miscella- neous Notes. Part 4 (out of print).—Composition and Quality of Indian Coals. Classification of the Vindhyan System. Geology of State of Panna with reference to the Diamond bearing Deposits. Index to Volume XXXILI. Vou. XXXIV, 1906. Part 1.—Fossils from Halorites Limestone of Bambanag Cliff, Kumaon. Upper-Triassic Fauna from Pishin District, Baluchistan. Geology of portion of Bhutan. Coal Occur- rences in Foot-hills of Bhutan. Dandli Coal-field : Coal outcrops in Kotli Tehsil of Jammu State. Miscellaneous Notes. Part 2.—Mineral Production of India during 1905. Nummulites Douvillei, with remarks on Zonal Distribution of Indian Nummulites. Auriferous Tracts in Southern India. Abandonment of Collieries at Warora, Central Provinces. Miscellaneous Notes. Part 3.—Explosion Craters in Lower Chindwin district, Burma. Lavas of Pavagad Hill. Gibbsite with Manganese-ore from Talevadi, Belgaum district, and Gibbsite from Bhekowli, Satara District. Olassification of Tertiary System in Sind with reference to Zonal distribution of Eocene Echinoidea. Part 4 (out of print).—Jaipur and Nazira Coal-fields, Upper Assam. Makum Coal-field between Tirap and Namdang Streams. Kabat Anticline, near Seiktein, Myingyan district, Upper Burma. Asymmetry of Yenangyat-Singu Anticline, Upper Burma. Northern part of Gwegyo Anticline, Myingyan District, Upper Burma. Breynia » Maltituberculata, from Nari of Baluchistan and Sind. Index to Volume XXXIV. Vou. XXXV, 1907. Part 1.—General report for 1906. Orthophragmina and Lepidocyclina in Nummulitic a Meteoric Shower of 22nd October 1903 at Dokdchi and neighbourhood, Dacca istrict. Part 2.—Indian Aerolites. Brine-wells at Bawgyo, Northern Shan States. Gold-bearing Deposits of Loi Twang, Shan States. Physa Prinsepii in Maestrichtian strata of Baluchistan. Miscellaneous Notes. Part 3.—Preliminary survey of certain Glaciers in North-West Himalaya. A.—Notes on certain Glaciers in North-West Kashmir. Part 4.—Preliminary survey of certain Glaciers in North-West Himalaya. B.—Notes on certain Glaciers in Lahaul. C.—Notes on certain Glaciers in Kumaon. Index to Volume XXXV. Vor. XXXVI, 1907-08. ; Part 1.—Petrological Study of Rocks from hill tracts, Vizagapatam district, Madras Presidency. Nepheline Syenites from hill tracts, Vizagapatam district, Madras Presi- dency. Stratigraphical Position of Gangamopteris Beds of Kashmir. Volcanic out- burst of Late Tertiary Age in South Hsenwi, N. Shan States. New suide from Bugti Hills, Baluchistan. Permo-Carboniferous Plants from Kashmir. Part 2.—Mineral Production of India during 1906. Ammonites of Bagh Beds. Mis- cellaneous Notes. Part 3.—Marine fossils in Yenangyaung oil-field, Upper Burma. Fresh-water shells of genus Batissa in Yenangyaung oil-field, Upper Burma. New Species of Dendrophyllia from Upper Miocene of Burma. Structure and age of Taungtha hills, Myingyan dis- trict, Upper Burma. Fossils from Sedimentary rocks of Oman (Arabia). Rubies in Kachin hills, Upper Burma. Cretaceous Orbitoides of India. Two Calcutta Earth- quakes of 1906. Miscellaneous Notes. Part 4.—Pseudo-Fucoids from Pab sandstones at Fort Munro, and from Vindhyan series. Jadeite in Kachin Hills, Upper Burma. Wetchok-Yedwet Pegu outcrop, Magwe dis- trict, Upper Burma. Group of manganates, comprising Hollandite, Psilomelane and Coronadite. Occurrence of Wolfram in Nagpur district, Central Provinces. Mis- cellaneous Notes. Index to Volume XXXVI. Vor. XXXVII, 1908-09. Part 1.—General report for 1907. Mineral Production of India during 1907. Striated boulders in the Blaini formation. Part 2.—Tertiary and Post-Tertiary Freshwater Deposits of Baluchistan and Sind. Geo- logy and Minerals of Rajpipla. Suitability of Rajmahal sands for glass-making. Vredenburgite, Sitaparite and Juddite. Laterites from the Central Provinces. Mis- cellaneous notes. The price fixed for these publications is 1 rupee (ls. 4d.) each part or 2 rupews (2s. 8a.) each volume of four parts. 15 PUBLICATIONS. The publications of the Department include— PALZONTOLOGIA InpicA, arranged in series, and sold in parts which are priced at 4 annas (4 pence) per plate. Memoirs, Vols. I—XXXVI, including the larger papers on geological subjects. Recorps, Vols. [—XXXV1I, including the shorter papers and Annual Reports from 1868 to 1908, sold in parts, price one rupee each. MAnvALs, GuIDES AND Maps. A compiete list of the contents of these publications can be obtained by application to the Registrar, Geological Survey of India, 27, Chowringhee Road, Calcutta. Indexes to the Genera and Species described in the Paleontologia Indica up to 1891, to the Memoirs, Vols. I—XX, and to the Records, Vols. I—X XX, have been printed for sale. GEOLOGICAL SURVEY OF INDIA. —_—_—_—.——_—_ Director. Sir Tuomas H. Hotzanp, K.C.1.E., D.Sc., F.R.S,, A.R.C.S., F.G.S. Superintendents. T. H. D. LaToucus, B.A. (Cantab.),.F.G.S. : C. S. Mrppremiss, B.A. (Cantab.) F.G.S. ; H. H. Haypen, B.A., R.E. (Dub.), F.G.8. Assistant Superintendents. P. N. Darra, B.Sc. (London) : E. W. Veepenzsure, B.L., B.Sc. (France), A.R.S.M., A.R.C.5., F.G.S. : L. LeicH Frermor, A.R.S.M., B.Sc. (London), F.G.S. : Guy E. Puteri, B.Sc. (London), F.G.S.: G. H. Tierer, B.A. (Cantab.) : H. Watxer, A.R.C.S., F.G.S., A.Inst.M.M. : H. Pascoz, M.A. (Cantab.), B.Sc. (London), #.G.S. : A, K. Hattowgs, B.A. (Cantab.), A.R.S.M., F.G.S. : G. pe P. Corter, B.A. (Dub.) : J. Cocain Brown, B.Sc. (Dunelm), F.G.8., F.C.S. : J. J. A. Pacz, A.R.S.M., A.I.M.M. (London) : H. C. Jonzs, A.R.S.M., A.R.C.S., F.G.S.: A. M. Heron, B.Sc. (Edin.) ¢ M. Sruarr, B.Sc. (Birmingham), F.G.S. : N. D. Darv, B.A. (Bom.), B.Sc. (London), A.R.S.M., Bar.-at-Law. Chemist. W. A. K. Curistiz, B.Sc., Ph.D. Sub-Assistants. 8. Sernu Rama Rav, B.A. : M. Vinayar Rao, B.A. E. K. Artist. Assistant Curator. BH. B. W. Garrick. T. R. Biya. Registrar. A. E. MacAvtay Avpstry, F.Z.S. Geological Museum, Library, and Office, Calcutta. i f j thas , ais ¥ a her : f, ie " i) i a , 7 a ct ' ND peers ate wie oO OTE Me Nee 7". ag A pe mee Bur nan Soe ae, Beka a ; eA no Mt | AMIN 100212936