= Fara e THE QUARTERLY JOURNAL OF THE GEOLOGICAL SOCIETY OF LONDON. EDITED BY THE ASSISTANT-SECRETARY OF THE GEOLOGICAL SOCIETY. Quod si cui mortalium cordi et cure sit non tantum inventis herere, atque iis uti, sed ad ulteriora penetrare ; atque non disputando adversarium, sed opere naturam vincere ; denique non belle et probabiliter -opinari, sed certo et ostensive scire ; tales, tanquam veri scientiarum filii, nobis (si videbitur) se adjun ant, —Novum Organum, Prefatio. VOLUME THE SIXTY-NINTH. 1915. LONDON : LONGMANS, GREEN, AND CO. PARIS: CHARLES KLINCKSIECK, 11 RUE DE LILLE, SOLD ALSO AT THE APARTMENTS OF THE SOCIETY. ie. rs ea g MCMXIII. : List OFFICERS Or TIL GEOLOGICAL SOCTETY OF LONDON. Busine Aubrey Strahan, LL.D., Sc.D., F.R.S. Wice-Prestvents, Prof. Ediwund Johnston Garwood, M.A. | Clement Reid. F.R.S., F.L.S. Richard Dixon Oldham, F.R.S. | Prof. W. W. Watts, Sc.D., LL.D.. F.B.S. Secretaries. Arthur Smith Woodward, LL.D., F.R.S. | Herbert Henry Thomas, M.A., B.Sc. SForetqn Secretary. Treasurer. Sir Archibald Geikie, O.M., K.C.B., D.C.L., | Bedford McNeill, Assec.R.S.M. LL.D., 8c.D., FBS. | COUNCIL. Henry A. Allen. | Edwin Tully Newton, F.R.S. Henry Howe Bemrose, J.P., Se.D. | Richard Dixon Oldham, F.R.S. Prof. Thomas George Bonney, Sc.D., | George Thurland Prior, M.A., D.Sc, LL.D., F.R.S. F.R.S. James Vincent Hlsden, D.Se. ' Clement Reid, F.R.S., F.L.S.° John William Evans, D.Se., LL.B. Aubrey Strahan, LL.D., Se.D., F.R.S. Prof. William George Fearnsides, M.A. Herbert Henry Thomas, M.A., B.Sc. Prof. Edmund Johnston Garwood, M.A. | Arthur Vaughan, M.A., D.Se. Sir Archibald Geikie,O.M., K.C.B., D.C.L., | Prof. William Whitehead Watts, LL.D... LL.D., Sc.D., F.R.S. | Se.D:, M.Se.; EB:S: Prof. Owen Thomas Jones, M.A., D.Sc. William Whitaker, B.A., F.R.S. Herbert Lapworth, D.Se., M.Inst.C.E. | The Rev. Henry Hoyte Winwood, M.A. ° Bedford McNeill, Assoc.R.S.M. Arthur Smith Woodward, LL.D., F.R.S., Horace Woollaston Monckton, Treas.L.S. | E.L.S. Assistant-Hecvetary, Clerk, and Librarian. L. L. Belinfante, M.Sc. Asststant-Ltbrartan. Assistant-Clerk. C. P. Chatwin. M. St. John Hope. Assistant tn Offtce and Library. Arthur Greig. STANDING PUBLICATION COMMITTEE, Dr. A. Strahan, President. Dr. A. Smith Woodward, | hae Mr. Herbert H. Thomas, J ZEB ARS Mr. H. A. Allen. | Mr. H. W. Monckton. Dr. J. V. Elsden. Mr. EH. T. Newton. Prof. W. G. Fearnsides. Dr. G. T. Prior. H Dr. G. J. Hinde. | Mr. Clement Reid. Dr. H. Lapworth. Dr. A. Vaughan. Mr. Bedford McNeill. Prof. W. W. Watts. TABLE OF CONTENTS. ArsBrer, Epwarpd ALEXANDER Newe.t, On the Structure of Dadoxylon kayt, sp. nov., from the Halesowen Sandstone at Natal cw ONVOLGESLCESMINE) = cies cists qnle aime eietniaw cium ates wd kaiae ale Baitey, Enpwarp Barrerssy. The Loch Awe Syncline, Arcyll- Slnnive,, We (eden O.O.G Bra. ©. G4) ) EU nee anaemia eai BosweEii, Percy Grorcr Hamnary. On the Age of the Suffolk Valleys: with Notes on the Buried Channels of Drift. (Plates NPC E) pseet een ct aks A er Aya twes LPN A auntie kod sho int Gia wD tga eae i Buckman, 8.8. The ‘ Kelloway Rock’ of Scarborough ........ Connopd, Epear StertineG. The Trilobite Fauna of the Comley Breecia-bed, shropshire. (Plates I & WN) 2d ee cs ——. Two Species of Paradoaides from Neve’s Castle, Shropshire. (Teleiidiss IEW) 2 BURG aT PTR aSTRI A eeu aeaane MI wet Ge Pn ae Davies, AntHuR Moriey (& J. Prinere). On Two Deep Borings at Calvert Station (North Buckinghamshire), and on the Paleozoic Fioer North of the Thames. (Plates XXXITI RU NONONGLIN AN eco AeA ie) ue Sy goles ehhh auat tho’ aa SIE Sti Dawson, Cuarues (& Dr. A. S. Woopwarp). On the Discovery of a Paleolithic Human Skull and Mandible in a Flint-bearing Gravel overlying the Wealden (Hastings Beds) at Piltdown, etching. Sussex.) (Plates MV—X VID) 6) a ols Furerr, Joun Smirn. [The Petrography of Bardsey Island.] .... Frost, Groree Atian. The Internal Cranial Elements and Fora- mina of Dapedius granulatus, irom a Specimen recently found MG Me Mast OharmMomthy iy pe ecm seek eee ee Ae seine Goopr, Racinaup H. On the Fossil Flora of the Pembrokeshire Portion of the South Wales Coalfield. (Plates XX VII-XXX). a2 on Page 454 280 508 252 iv TABLE OF CONTENTS. Page Hoorry, Reernatp WattTER. On the Skeleton of Ornithodesmus Tonite an Ornithosaur from the Wealden Shales of Atherfield, peslevoteWirht:) (Plates XXX Vil) ne pee ee eee ene 372 JOWETT, ALBERT. The Volcanic Rocks of the Forfarshire Coast and the Associated Sediments. (Plates XLV & XLVI)..,... 459 Kay. Henry. On the Halesowen Sandstone Series of the South Statfordshire Coalfield, and the Petrified Wood found therein at the Witley Colliery, Halesowen, Worcestershire. (Plates SOUT & KGW) te recs eget eae le ee eee 433 LANE, GEORGE JoHN. Notes on the Stratigraphy of the Marske Qua Try. a ye ea al dhe diepialeteucee tans Renee ee ee ee ee 249 Marr, Jonn Epwarp. The Lower Paleozoic Rocks of the Cautley District ( Workeshire,) favs tyen ce aan Nene Bar see once pn e aneenaa if Matitey, CHaRLtes ALFRED. The Geology of Bardsey Island. (Plates TEN Ga) ieccbet ch cis ts elehetiee ae sts eae a ee 514 Monckton, Horack fy OTIZONM eas. z sub-brongniarti, pl. xxvii) | earalone teat: RARE He aCe i Tt Oe ete | J Marattiopsis anglica, fig. 1 © pl. xxiii, figs 1-5 ............| Lower Oolite...| Marske ....... Matonidium 9 gepperti, fig. 2c) \ ( Wolo, Baily, thes Gh“ eeAadBenoee | | Fairlight....... Onychiopsis MANTLE ... 020.0000 | | Pelleticria EES gen.etsp.| } Fairlight Clay . 4 Fairlight & nov., figs. 24, 5, 4 & pl. xii, Hack figs. 12 a—-12 4, pl. xiv, fig. 5.| | poise hae Ruffordia gepperti, fig. 2a ...|) | \ Fairlight....... Sagenopteris acutifolia, pl. xi, . fig. + — mantelli, pl. xi, Be Un ceaanet bak Fs oe phillipsi, var. major, pl. xxv, fig. 2 Sphenopteris schillingsi, pl. xxx, \ TER 4 Ci mee ADO eA Teilhardia valdensis, gen. et sp. nov., pl. xi, figs. 7 a-9 d. Todites williamsoni, pl. xxiii, HOM OM eertoataceaesack iat ohne. Lower Oolite...| Marske ....... CycaDoPHyTA. Ctenis sp., pl. xii, figs. 1 a, 1 4,) | CO A UNL EB Ae | Wealden Beds...| Sussex.......... Dictyozamites hawelli ......... Lower Oolite ..... Marske ....... Hury-Cycadolepis,, fig, 6 &| pl. xii, figs. 8 a-4c, pl. xiv, HOME ea ackSecnlct oe ss sk ct Fairlight Clay . Fairlight....... Nilssonia mediana ..........2..4. ne orientalis, pl. xxiii, fig. 7 | & pl. xxv, fig. Ey Bsa Jopoonea aus Lame Oolite ... { Marske ....... Otozamites feistmanteli......... | | | ROPMICUS Tee eI ) ( Fairlight Clay Wealden Beds . Ashdown Sands. Lower Oolite .... Marske ‘ Millstone Monkstone Grit’ Point Ecclesbourne ... Fairlight....... .| Eeclesbourne ... | x1 Page 97 OL 101 238-39 101-1038 (239-40 | { 240-42 | 237-38 | (238 Xxll Formation Name of Species. ion. FOSSILS FIGURED AND DESCRIBED. Page Cycaporuyta (continued). Otozamites klipsteinii, fig. 5 ...| | Pseudoctenis lanei, sp. nov. pl. xxiv, fig. 4 & pl. xxvi ...| Ptilophyllum (Williamsonia)| pecien, figs. 3 & 4 ..........-.| Tentopterts Maj0r .........0..06. CURHIETED\: -naduondoogesoeeOnanee a ST aleccnergu nce Snoncune creer Wi ann la (Anomozamites )| DOSSOIIO. Sanaa nae OCR peBBORREAE Williamsonia carruthersi (2)...| —— spectabilis, fig. 2 & pl.) xxiv, figs. 1 a-3 whitbiensis Ss sp.. Zamites (Williamsonia) gigas., Baiera longifolia, fig. 5 & pl.) xxv, figs. 5-4 i setts certs scores Araucarites pippingjor -densis . sp., pl. xii, fig. 5 Dadoxylon kayi, sp. nov., figs. OR are vaca cieciaeen ees Hllatides setos@ .......2.0....005- IPANLUES) SOUS even ee ecnce eee = sp. ef. dunkeri, pl. xii, HSS MOV Ty erecenwc eee ncslciett Sphenolepidium kurrianwn, pl. xii, figs. 10a &100...... Tawites zamioides ............4. Plante incerte sedis « & B, pl. xii, figs. 8, 9, & 11 ercece Fairlight Clay . An \ Lower Oolite ... s\ GINKGOALES. Lower Oolite rel ConIFERALES. \ Fairlight Clay Halesowen Sandstone ... Lower Oolite ... Wealden Beds . Fairlight Clay . Wealden Beds . Lower Oolite ... Wealden Beds . Wealden Beds... | \ Lower Oolite ... PLANT INCERT& SEDIS. Conites berryt, sp. nov., pl. xii,| Vetacapsula minima, sp. nov.,| pl. xxx, fig. 3 Weaiden Beds . i Lower Coal Series SEMINA INCERTA SEDIs. Cardiocarpus acutus, pl. xxviii,| THE, (- esconosesoactoeoasboannpaas \ Pennant Grit (?)! horizon | Vance Cliff End, Hastings ...... 99-101 ( ( | 249-43, | | 934-35 4 Marske ..... ... 4 236 | | 235-36. | 237 : | L | 237 Fairlight......... 99 ( { | | 280-82: 4 Marske ......... 4 233 | | 2388 \ | \ 234 Marske ......... | 243-45. ae 6 104 Fairlight......... | (ero Watley cise. se= | 454-57 Marske ......... | 246 Sussex ............ | 104-105. Fairlight ......... | 105 Sussex ......000-.- 105-106. Miarsker 2.5... 22 | 245-46 Sussex. ...-...0s | 106 Snesex 2c ee | 108-104 Bridge Patch 265-67 Madoe’s Haven. 276 EXPLANATION OF THE PLATES. PLATE PAGE oe oF THE Rock-BaRRIpR AT THE SOUTHERN END ) or THE VeJTestranps Lake; and GorGE, wirtt | 7 BIG POTHOLE, AT THE SOUTIERN ENP OF THE SAME} 19 LAK, illustrating Mr. H. W. Monckton’s paper | { on the Hafslo Lake aud the Solvorn Valley ...... ) { Mippte CamBriAn TRILOBITES FROM CoMLEY ) Snrorsntre), illustrating Mr. EH. 8. Cobbold’s ion omic Je lls eee ( paper on the Trilobite Fauna of the Comley | Breccia-Bed ......... SESE Rca ister sitter ee nase . ParaDoxipes FRoM Never’s Casrit (SimrorSHIRe), | f 45 IV illustrating Mr. E. 8. Cobbold’s paper on those POSSTLSCH MEW. SAAS Ue ee cial aiencratee eect ne sinealgaenie sates | TRANSVERSE AND LONGITUDINAL SECTIONS OF VARIOUS VIX SPECIMENS OF AuzLopHYLLUM, illustrating Mr.} 51 Stanley Smith’s paper on that genus ............ .. Hotoprycuius AND BoTHRIOLEPIS FROM THESOUTH- i x ALL Borin, illustrating Dr. A. 8. Woodward’s notes on those fossils 81 ( Heviserites, Lycopropires, Lacenoprerirs, Dicuo- \ PTERIS, T'EILHARDIA, and Frurx incert. sed. ; ‘| | Crenrs,uRY-CYCADOLEPIS, ARAUCARITES, PINITES, XT_XIV SPHENOLEPIDIUM, PELLETIERIA, ConirTes, etc.; ! me 4 CLADOPHLEBIS BROWNIANA (Dunk.); and Hus- i | uaAnnrA, Maronipium, PriLerrerrsa, APHLEBIA, AnD Hury-Cycapocepzs, illustrating Prof. A. C. | | Seward’s paper on Wealden Floras ....... obese at } (Ee BEARING GRAVEL-BED OVERLYING THE Tun- ) Bripcge Wetts Sanps (Hastings Bens) at Pitrpown, Furrcnine (Sussex); PaLmouirus and ‘Hourrns’ from the same locality; Skunu AND ManpIBLe or HosnrTHROPUS DAWSONI; and a OLT Maymantan Remains found with the nee: Li illustrating the paper by Mr. C. Dawson & Dr. A. S. Woodward on the Discovery of a Paleolithic Skull and Mandible at the above- mentioned locality..................0.0.-020- deere Mat Aa) — (Mare or tHE Harriepoon AREA, SHOWING THE ) Positron or THE ANHYDRITE AND THE Maanustan | XXII{ = Limesrons, illustrating Mr. OC. T. Trechmann’s } 185 paper on a Mass of Anhydrite in the Magnesian | Limestone at Hartlepool .................. Fee Catia) —— XIV EXPLANATION OF THE PLATES, PuaTE Jurassic Puants From Marsxz, illustrating Mr. H. Hamshaw Thomas’s paper on the Fossil Ficra of the Marske: @uerniy: Gsnes bens se cee acreet a aen XXAITIEXXVI R. H. Goode’s paper on the Fossil Flora of the Pembrokeshire Portion of the South Wales Woal field hye ee MRO US ee a XXVII-XXX | cane Coat-Mpasure Puants, Ree Pitow-Lava, An Arrp (weEsTERN coAsT or TAy- VALLICH Puyinsuna) ; ; and Marv or rue Locn Awe Syncnineg, illustrating Mr. EK. B. Bailey's pee on that syncline............... ea aia t eat ee eae eae eee XXXI & XXXIT (Micrornorograrus or Rocks rrom tHE CaLyert | | Bories; and Mar or part or Soura-Cunrratu | XXNITI&XXXIV{ = anv Sourn-Hastrrn Eneuanp, illustrating the + | paper by Dr. A. M. Davies & Mr. J. Pringle on |} ( ] the above-mentioned borings .....................-+- ) ( Sxerco-Mapr or run Maxay Penrysuna, illustrating | XK Mr. J. B. Scrivenor’s paper on the Geological iHnstoryottbatmesonheeeseessrey sess eee eee ORNITHODESMUS LATIDENS, illustrating Mr. R. W. } AON TXT Hooley’s paper on that fossil Ornithosaur......... f u ( PERISPHINCTES EASTLECOTTENSIS, Sp. noy., illus- XLI & XLII trating Dr. H. Salfeld’s paper on certain Upper | Jurassic Strata of Hmeland)......--..-...-......ss8-e: ( Pemurm Log EMBEDDED IN FrRrucinous Cat- ) cCAREOUS SanpDstonn, Wirtny Couiinry, & LARGE Perriiep Log ww Wrrney Connery Rarway- | MGM & XLIV2 courting ; and Grotoarcan Map or tire Hares- \ F OWEN SANDSTONE AREA OF THE SoutH STAFFORD- { | SHIRE Coanrisnp, illustrating Mr. H. Kay’s | paper on the Halesowen Sandstone Series el that coalfield............ Saas ou ls EAR an ) ( Lavas anD Sanpstroyus or THE Forrarsmire Coast; \ | and Micrornorocrarus or Rocks FRom TAT | XLV & XLVI4 ~ Coasz, illustrating Dr. A. Jowett’s paper on the } Volcanic Rocks end Associated Sediments of | {. the Forfarshire Coast .......... sot Watlsuis Renae Hanan ) ( View or Upper Green Hit Quarry (HASTERN END) | & or Lowrr Green Hirn Quarry; and Micro- | ALVIL& XLVITi{ = Pevnorograrus or Rocks & Annuwip (?) TUBES } | Rom THE Oxrorp Barnontay, illustrating Mr. | M. Odling’s paper on that formation............... ) (IyrerBeppmp Bayps passing Into Crusu-Con- | | GLOMERATE & Quartz-KNOB ON THE WESTERN XLIX & L{ srorn or Mynypp Enurt; and Gronoarcan Map \ | oF Barpsry Isnanp, illustrating Dr. C. A. | {| Matley’s paper on the Geology of that island ... ) PAGE 252 280 438 459 514 Urrrer Stour Vauinys, illustrating Mr. P. G. f H. Boswell’s paper on the Age of the Suffolk | Gu Vialleve ebea Wccte vec SP OANS day ee aE tH Marea m2 te ) EXPLANATION OF THE PLATES, XV PLATE Paar Scuists AND Gwyerss rrom Bririsn Hasr Arrica, LI illustrating Mr. J. Parkinson’s paper on a 534. Group of Metamorphosed Sediments situated : between Machakos and Lake Magadi............... AMMONITES FROM JeBEL ZaAcuvan, illustrating] - 4, ; ee Ds : 540) re LUI | Mr. L. F. Spath’s paper on those fossils ......... Je (Mar or SuFroLkK suowine tHE Rivur-Systeus & ) | THE Position OF THE ToP oF THE CHALK; and NTouRED Maps or Tum Guippinc, Bretr, AND{ - LIV & LV4 Contou APS OF THE GI @: t, \ 582 | (Mav or Borines, showing ContTour-LINEs ON THE ) | PAtmozorc PLatrorm; Mar suowine Conrour- | LINES IN THE Basu or THE GAULT; and Map | A-C4 sHowInG Tun Conrour-Lines or THE Patmozorc + lxx PLATFORM, CORRECTED ror vost-Creracnous | Movements, illustrating Dr. A. Strahan’s Presi- (aidlentialicA ddressm.wsseeat on. Gs. cagunuacenem sehr aetacts PROCESS-BLOCKS AND OTHER ILLUSTRATIVE FIGURES BESIDES THOSE IN THE PLATES. PAGE fie. 1. Section in Backside Beck from the Ludlow Fault to Swemoa 2 sc aisesvaovoneias ols sae oBaeaus soma somm ase emesees 6 My Ikea Oe Seren ene LEW ATES coococucsoncqee sca cobroascaossa0 ca 9000" 10 1. Geological sketch-map of the neighbourhood of the Hafslo liakeyand ithe way ster MjOrd 9. .sessee esse eee ee eee eee 20 2, Diagrammatic section from the Hafslo Lake to the Lyster AOU Me Se asieciclsan sels auhincletaiat neeincte ceranetclstes ace oeee eect eee ceee 22 I, Alantoppiconiaaii,, MENTOR SVAS cococcosncqopaoncsnsaj0densuosesnanconeae: 58 Fies. 2-5. [Septal plans illustrating the growth of the corallum Min AUL Oph eyULWT oa. scos ~cuek sesianeeaaetteeoset ed eet e eee eee ee eeeee 60-61 Fig. 6. [Diagram illustrating changes in the structure of the Coralia invA ophey line neecnecees ce eee eee eae eee eee 63 (9) (Outline figure of Aulophayllmm)|) .c--s-bee-2essecee seer eee oae 65 8. Coral exhibiting effects of rejuvenescence ...............06.06+ 73 9. Vertical but tangential section cut through a coral, through the point of rejuvenescence R—R in fig. 8 ...... 74 1. Selaginellites dawsont, sp. NOV. .........c0ce..2e2seceeseecesneceee 87 2. Spores of Ruffordia gepperti, Pelletieria valdensis, and MMGLonidium) Ge ppertt s,s ccna. see eeeera eee eeeEeee eRe eee 91 Fies.3 & 4. Pelletieria valdensis [fronds and spore-masses]............... 92, 93 Fig. 5. Otozamites klipsteinii, natural size ..........0.e.eseseseeenseeees 100 6. Hury-Cycadolepis, casts of stems with scales ............2....- 102 1. Plan of the basin of the Sussex Ouse, showing the distri- bution of iron-stained flints and flint-bearing gravels ... 118 PROCESS-BLOCKS AND OTHER ILLUSTRATIVE FIGURES. ~ XYil Pace Diagrammatic section of the Weald, showing the low plateau on the south capped by flint-bearing gravels ... 120 Fie. to 3. Sagittal section of the Piltdown skull superposed on that Ofmanslulll strom Mewes Wlevels ecer--crsecess.cecsca tener seo: 126 4, Restoration of the Piltdown mandible compared with that of man and the young chimpanzee, in left side view...... 135 PRE ISANNG SMP VIEW, Won .jeceacsgesviotdevecnapentcdepenensse oddone 134 -35 Gaeethic same, NOW ELE VIG Was ssi tos ces eseieects ceeectae a oisa ub esineuts 136-37 7. Mandibular ramus from Piltdown superposed on that of LO TL Og CUDEVOET GO LUSTSI oy ee aaeats ante See een seer dasa sle'sceaiast Oa 138 Fires. 8-10, Outlines (left lateral view) of the skull and mandible of the young and adult chimpanzee, and of Hoanthropus dawsoni, also of the human skull and mandible from 1Deiy (Olniesollle enbb:< Sent altls\ oe Sosstinacnsecbocectinosnec condaadueasroctc 140-41 Fic. 11. Left norma lateralis of the internal cast of the skull from AP bal o wants. schjAatenesuae cen mcatinc ea cise es tciaetita ce pesielsparinn siete 145 I. Vertical sections of borings in the Hartlepool area ......... 192 2. Section from the sea-coast at Throston (Hartlepool) to Wiest lartlepoolyWiaterwonles\ouasseterss- seas stseteives acl 194 8. Ideal section of the Permian, from the shore at Blackhall Colliery to the Escarpment near Coxhoe .................. 200 1. Cranial foramina of Dapedius granulatus .......0.0200.0ec0ee 219 2. Cranium of Dapedius gramulatus .......0002.cceccscecnscscnsnese 220 Ils ISYBOIRES Olt AWGMenTOOSIS CUHOWTERD sacncadd=caone0 odosandnbencoo0ecGAbS 229 2. Restoration of an almost mature male flower of William- SOHO SIAC HOS INAWTOERN, scoonenaconssed Hob oocosoosnDde on CoDU: 231 Outlines of portions of two types of fronds referable to the ageregate species Piilophyllum (Williamsonia) pecten ... 234 oo 4, Another type of frond of Ptilophullum (Williamsonia) pecten, showing the basal lobes of the pinnee ............... 235 5. Epidermal cells of Baiera longifolia, showing the charac- teristic papillz and stomata on the lower side ............ 244 1. Geological map of the Pembrokeshire Coalfield............... 254 2. Calamites wndulatus Sternb.: external surface, showing root-scars below the node ........... Richa Mal a scae ie anu oat a 262 1. Pillow-lava, Rudha Barain, western shore of Loch Awe ... 285 9 Deformed pillow-lava, Rudha Cuillin, eastern shore of Tiuorgitl BGs added Aaa eo Pa Dae ee heen Ue ae tole Aan MeN aa Sie 286 3. Breccia containing epidiorite - fragments interbedded between fine-grained limestone and gritty limestone...... 288 yon. LXIX. b xviii Fia. Kies. 4&5. Fig. 5 o, 6&7. 8. wy or to PROCESS-BLOCKS AND OTHER ILLUSTRATIVE FIGURES. Volcanic section south of Port an Sgadain, western coast of Tayvallich Peninsula................. A aip biceps Renee ERE Vertical section of the eastern boring [Calvert]............... Orbiculoidea aff. holdent Tate .............s.seseeceeeeeeeeeeeeees Cnattelttes (CD) eurk, Sali VETO seseimecooemcccesancnsedactencsesco.07- Diagram illustrating the formation by faulting of the lime- Stoneyhnls im the shomita nV allleyyemeseee se hee cease ae aaa Section of the Tronoh opencast mine, looking north-north- TICSIDU/CUNG ISI arasnre seeBeDEACeHosanona adaccuscasos Ede Stes Beart Section through Cradley and Hasbury to Hunnington...... Section from Yewtree Farm to Mucklow Hill ............... Section from Wassel Grove to Witley Colliery ............... Sections from Wassel Grove to Oldenhall Colliery and from Oldenhall Colliery to Witley Colliery ............... Transverse & radial sections of Dadoxylon kavyt, sp. nov...- Greatly enlarged sketch of part of a tracheid of the same, NSS ECHO TUM LKOUEL RYE MOYO, soo ccuonecosoDee sduddssanacuasdasssocaco: Man sentially seetionkoty the Sane sees eee =eeee reese een eee eer eee Geological map of the coast, from Mentrose to Fishtown Ol Usa. Hein cca lenetestcn theme Genesee weeheenee eee eeaceee Plan of the junction between conglomerate and laya, north- eastiofHishtowmneots W sani. -ceestese esse eenee ease eee ee er eee Geological map of the coast, from near Fishtown of Usan (nfo) waver biiewMSl Bay REN ASIS).| Aoodencscbsecososeoocbasoceedsccsnsnon: Geological map of the coast, from the Lunan-Bay sands to thewRed Hie 2.25: occ cel ecsne tener se see rentonee cee eee eee Diagrammatic section along the coast, from the Red Head to Hthie Haven and the south-western corner of Lunan DB avy ioesaeice eis dediok dvnutiats atdiadce sore Giese See Re eee EC Re eee eee Beene Map showing the principal Bathonian exposures in the OxfordiGistrict /\vscy...<8esnesee sree science eee eee eee Section from Ardley to Fritwell Tunnel, G.W.R. (new Burning hamenaaimelin eos. ererese erence see eee ee nee eee erase ee View of the upper part of Gibraltar Quarry .........-........ Vertical sections illustrating the correlation of the principal exposures in Oxfordshire of Cornbrash and Forest Mia Dietetics sescccocsatstccssiaececas weenie eee ee Vertical sections illustrating the correlation of the principal exposures in Oxfordshire of Great Oolite and Fullonian . Pace 296 314 463 464 468 48x 497 p08 509 PROCESS-BLOCKS AND OTHER ILLUSTRATIVE FIGURES. P0616 Pct Fre. 1. Section on the northern coast of Bardsey .................000 OT 2. Section from the south-eastern coast of Bardsey to the Oe Wy CSTE LM COMMEM sen ets 0h ec we cidctis ana ee iee da caleidembawccs 520 3. Section along the south-western coast of Bardsey............ 520 4, Sigmoidal fold on the ridge of Mynydd Enlli, at the 300- Loop contour, lookimaimorthy {sen sesccnsuses-cMe-terece tsetse. 522 5. Overfolding in quartzite-bands interbedded with slates ; clittiwestiol:Pemy Onistine 52 yeseyse se etoccecns sce sooedewenec ack 523 6. ‘Crush-conglomerate’ in the cliff at Pen Cristin ............ 524 Geological sketch-map of part of the district between the Uganda Railway and Lake Magadi ...................0.:0.06 536 Fras. 1-4 [illustrating typical radial lines in Protogrammoceras)...... 581 Fie. 1. General section across the Gipping (Orwell) Valley at swe hlibtrssmctineaes wa iene Wvaase da s\smaccedueentdale decease 588 Figs.2&3. Longitudinal sections down the Brett and Gipping Walley sh-gtema team Schade tac lagtavcttalestanekagaateeatse acces te 600 BiGa mm Ketch -ma pot Ms WwiIChs.f.cc. is oodhewe sac docisachawerccctcsevactseaes 602 5. Cross-sections of various Suffolk river-valleys ............... 614 1. Hornblende-fels, G.S.M. 8140, Ravensthorpe.................. 639 2. ‘Archipelago’ of quartz in quartz-dolerite-greenstone, Hevea oe GME ve eeee sc see- oboe So aucooab=or deetene ead uarmelodsc 649 3. Albitized porphyrite, Power-House Reserve .................- 56 CORRIGENDA, P. lxxxvili, in the List of Borings, seventh column, opposite ‘ Meux’s Brewery,’ for ‘ Lower Greensand, 64’ read ‘ Great Oolite Series, 64.’ P. 200, last line of the footnote, for ‘ Whitby’ read ‘ Whitley,’ Dates of Issue of the Quarterly Journal for 1913. No. 278—April 25th, 1913. No. 274—July 29th, 1913. 25 » No. 275—October 29tn, 1913. i i ‘ No. 276—January 20th, 1914. nan LOL DODO OOOO OOOO aoaOOY Vol. LXIX. MARCH 1918. No. 273. Parr 1. THH QUARTERLY JOURNAL OF TIS GEOLOGICAL SOCIETY. EDITED BY THE ASSISTANT-SECRETARY. [With Twenty-one Plates, illustrating Papers by Mr. H. W. Monckton, Mr. E. S. Cobbold, Mr. Stanley Smith, Dr. A. S. Woodward, Prof. A.C. Seward, and Mr. C. Dawson & Dr. A. 8. Woodward. | LONDON: f LONGMANS, GREEN, AND CO, /y,,. lonal | PARIS:—CHARLES KLINCKSIECK, 11 RUE DE LILLE: ~~~ SOLD ALSO AT THE APARTMENTS OF THE SOCIETY. Price Five Shillings. Oo PPI [Issued April 25th, 1913. ] LIST OF THE OFFICERS AND COUNCIL OF THE GEOLOGICAL SOCIETY OF LONDON. nn Ao eet Elected February 21st, 1913. LOS President. Aubrey Strahan, Sc.D., F.B.S. Wice-PrestVents. Prof. Edmund Johnston Garwood, M.A. Richard Dixon Oldham, F.R.8. Clement Reid, F.B.S., F.L.8 Prof. W. W. Watts, LD, SeD., E.R.S. Secretaries. Arthur Smith Woodward, LL.D., F.B.S8. PHoveign Secretary. Sir Archibald Geikie,K.C.B.,D.0.L.,LL.D., Sc.D., Pres.R.8. | Herbert Henry Thomas, M.A., B.Sc. Greasurer. | Bedford McNeill, Assoc.R.S.M. COUNGIL. Henry A. Allen. Henry Howe Bemrose, J.P., Se.D. Pr of aes George Bonney, Se.D., LL.D., James Vincent Elsden, D.Sc. John William Evans, D.Sc., LL.B. William George Fearnsides, M.A. Prof. Edmund Johnston Garwood, M.A. Sir Archibald Geikie, K.0.B.,D.C.L., LL.D.., Se.D., Pres.R.S. Prof. Owen Thomas Jones, M.A., D.Sc. Herbert Lapworth, D.Sc., M.Inst.C.E. Bedford McNeill, Assoc.R.S.M. Horace Wollaston Monckton, Treas.L.8. Edwin Tully Newton, F.R.8. Richard Dixon Oldham, F.R.S George Thurland Prior, M. wNG, D. Sc., F.B.8. Clement Reid, F.R.S. FE. L. S. Aubrey Strahan, Sc. 1 E.R.S. Herbert Henry imine! M.A., B.Sc. Arthur Vaughan, M.A., D.Se. Prof. William Whitehead Watts, LL.D., Se.D., M.Sc., F.R.S. William Whitaker, B.A., F.R.S. The Rey. Henry Hoyte Winwood, M.A. Arthur Smith Woodward, LL.D., F.R.5., ELS. Assistant=-PHecretarp, Clerk, and Librarian. L. L. Belinfante, M.Sc. Assistant-Librarian. C. P. Chatwin. Assistant-Clerk. M. St. John Hope. Assistant tr @ffice and Library. Arthur Greig. STANDING PUBLICATION COMMITTEE. Dr. A. Strahan, President. Dr. A. Smith Woodward, Herbert H. Thomas, Mr. Mr. H. A. Allen. Dr. J. V. Elsden. Mr. W. G. Fearnsides. Dr. G. J. Hinde. Dr. H. Lapworth. Mr. Bedford McNeill. z Secretaries. Mr. H. W. Monckton. Mr. EH. T. Newton. Dr. G. T. Prior. Mr. Clement Reid. Dr. A. Vaughan, Prof. W. W. Watts. EVENING MEETINGS OF THE GEOLOGICAL SOCIETY TO BE HELD AT BURLINGTON HOUSE. Session 1912-1913. 1913. Wednesday, May . June Coe sen coneseedusessesese Cee leer cara sscrsercesess [Business will commence at Hight o Clock precisely.| The asterisks denote the dates on which the Council will meet. THE QUARTERLY JOURNAL OF THE GEOLOGICAL SOCIETY OF LONDON. WiOGs EX Xe 1. The Lower Patmozoic Rocks of the Cavrney Disrricr (YorxK- sHIRE). By Joun Epwarp Marr, Sc.D., F.R.S., F.G.S. (Read December 4th, 1912.) Tue object of this paper is to establish a more detailed successiom for the Ordovician rocks of the district, and to offer some notes upon the faunas of the Silurian rocks, the detailed succession of which) has already been established. I wish to thank the members of a party who accompanied me on: an excursion, for much help in collecting. They were Messrs. A. W. R. Don, W. B. R. King, R. U. E. Knox, T. C. Nicholas,, J. Romanes, and Bernard Smith. My son, F. A. Marr, has also: rendered much assistance on several occasions. Fossils were collected on Sally Brow many years ago by Prof. McKenny Hughes, and Mr. Fearnsides has also supplied several specimens. I would especially thank Mr. J. Middlebrook, who placed his valuable local collection at my disposal, and ultimately presented it to the Sedgwick Museum. I am greatly indebted to Miss G. L. Elles, D.Sc., for her kindness: in identifying the Ordovician graptolites. The Geological Survey Memoir, ‘The Geology of the Country around Mallerstang....,’ explanatory of Quarter-Sheet 97 N.W.. (n. s. Sheet 40), has naturally been of great use. In this memoir a: bibliography of the geology of the area up to the time of its publi- cation (1891) is given; this renders it) unnecessary to append one: here. Q.J.G.8. No. 273 2 DR. J. E. MARR ON THE LOWER {March 1913, Some brief notes on the rocks by myself and Mr. W. G. Fearn- sides were published in the Report of the British Association (Sheffield) 1910, p. 603. Tt will be well to give here a table of the strata as developed in the Cautley district :— Bannisdale Slates. Coniston Grits (in a re- stricted sense). | coldwell Beds. SILURIAN ...... 4 Wenlock -......-- Brathay Flags. lee Ludlow (Salopian.. f Tarannon! sess. ( Valentian | Stockdale Shales. \ Llandovery , Ashgillian. Caradocian. ORDOVICIAN... A. THE ORDOVICIAN STRATA. A reference to the Geological Survey map shows that these strata are developed in three elliptical patches in the form of an inverted L, with a strip running southwards from the end of the north-westerly mass. As these ellipses are denuded domes, the Caradocian rocks, on the whole, form the central portions, and the Ashgillian beds their peripheries ; but, as there is much folding and faulting, there are naturally exceptions to this general statement. One of the most satisfactory exposures is developed in Backside Beck, which cuts through the north-westerly dome in a general north-and-south direction. As the south-eastern side of this dome is faulted out, there is an ascending sequence as one proceeds up stream. This section will constitute the type-section, and after- wards other sections will be described, which are confirmatory of the succession established in the beds of Backside Beck. No attempt will be made to estimate the thickness of the rocks. They certainly include several hundreds of feet of strata. A very detailed account of the section is given in the Geological Survey Memoir (pp. 20-26). Fig. 1 (p. 6) shows the subdivisions which I propose to make. The lowest beds are blackish shales, with impure blue-black limestones, which extend from the south-eastern end of the dome for a considerable distance up stream. The exact junction of these beds with those that succeed them has not been determined in this beck; but the lower beds extend at least as far as a point a few yards south of a ruined footbridge mentioned in the Survey Memoir. This bridge is 350 yards south-south-west of Mountain-View Farm. Up to a point near the footbridge the beds yielded a Caradocian assemblage of fossils. The following have been obtained :— Trinucleus seticornis His.? (common). | Calymene planimarginata Reed (com- Remopleurides sp. (rare). mon). Illenus bowmanni Salt. ? Orthis calligramma Dalm. Cybele verrucosa Dalm. Plectambonites sericea Dalm. Vol. 69. | PALAIOZOIC ROCKS OF THE CAUTLEY DISTRICT. 3 The most abundant fossil here, as elsewhere in these beds of the district, is the Calymene. The form is that recorded by Salter as C. senaria Conrad in the Sleddale Beds of the Lake District. Mr. F. k. C. Reed has, however, shown that the form is not Conrad’s species, and has given it a new name, C. planimarginata.' From its abundance, the beds will be referred to as the Calymene Beds. I have hitherto found no form of this or any other species of the genus in higher Ordovician deposits of the Cautley neighbour- hood; it is, therefore, a particularly characteristic fossil. Above the highest exposure with Calymene a considerable thick- ness of similar strata occurs, which has yielded, so far, neither the Calymene nor any characteristic fossil of the succeeding beds; and in Backside Beck, therefore, one cannot, within a limit of 100 feet or more, draw a line of demarcation between the Calymene Beds and the succeeding strata, to be next described. In other words, it is not at present possible to indicate here the exact line of sepa- ration between the Caradocian and the Ashgillian strata. The first characteristic assemblage of Ashgillian forms has been found about - 300 yards higher up the stream than the point yielding the last Calymene; as, however, the strike is, for some distance, nearly parallel to the stream, and a considerable stretch is occupied by a felsite sill, the thickness is not very great. The evidence, on the whole, is in favour of the beds immediately above the ruined foot- bridge belonging to the lowest Ashgillian group. Impure limestones and calcareous shales immediately above the bridge have yielded Turrilepas ; and a little higher up, just below the felsite sill, a specimen of Strophomena corrugatella occurred. Lithologically, the beds suggest rather Ashgillian than Caradocian deposits, but one cannot lay much stress upon this point. Where the northern wall of a pasture west of the beck comes down to the stream, beds occur with Remopleurides and Phacops robertsi, striking generally along the stream to the junction of Watley Gill, where they form a cliff on the right bank of Backside Beck. These beds are lithologically similar, on the whole, to those of the Caly- mene Group. Like the latter, they consist of shales and impure limestones. ‘The shales, however, are generally lighter in colour, grey rather than black, and have an unctuous feel ; but individual bands are quite similar to some of the Calymene Beds. Similar as are the lithological characters of the two groups, their faunas are markedly different, and the fossils of the upper group have a distinctly Ashgillian facies. Jtemoplewrides and Phacops robertsi occur throughout, the latter being most abundant near the base. I shall speak of these beds as the Phacops-roberts? Beds. Fossils occur in the limestones as well as in the shales, and, although in the former they are usually fragmentary, the details of structure and ornament are beautifully preserved. The following is a list of forms found in the Phacops-robertsi Beds of the beck :— 1 See ‘Lower Paleozoic Trilobites of Girvan’ pt. 3, Monogr. Palzont. Soc. (1906) p. 187. B2 + DR. J. E. MARR ON THE LOWER [March 1913, Monticuliporoids. Menus. Dicellograptus anceps Nich. Phillipsinella parabola Barr. (fre- Turrilepas. quent}. Trinucleus seticornis (2). Lichas. Ampyx tumidus Korbes ? Cybele rugosa var. attenuata Reed ? Remopleurides (Caphyra) radians Phacops (Dalmannites) robertst Reed Barr. (one specimen). (very: common). R. (Caphyra) sp. 1 (very abundant). Phacops (Pterygometopus ?) sp. (rare). Remopleurides (sensu stricto) sp. 2 | Phacops (Acaste) cf. downingie (two specimens). Murch. (common). The succeeding beds will be spoken of as the Staurocephalus Beds, although the index-genus has not hitherto been detected below the contemporaneous volcanic rocks which occur near the middle of the division so named. A few yards above the mouth of Watley Gill the main beck shows a passage from the Phacops-robertsi Beds into hard, blue, flaggy mudstones which extend up stream to the point where the beck leaves the moorland above to enter the highest part of the enclosed ground up which we have been tracing it. On reaching the moorland, we note that calcareous beds become important ; and a thick white limestone, with fragmentary fossils, recalls, as regards lithological characters, the Keisley Limestone. I shall speak of the strata from the top of the Phacops-roberts: Beds to the base of the voleanic group as the ‘beds below the voleanic group.’ They have yielded here :— Dicellograptus anceps. Ateleocystites (2). Climacograptus normalis Lapw. Trinucleus. Glyptograptus persculptus Salt. Tlleniis. Tentaculites anglicus Salt. Orthis. Above the beds just described comes the contemporaneous vol- canic group, of which a full description is given by Dr. Strahan in the Geological Survey Memoir. It is associated with fine ashy calcareous shales, which weather olive-green. Similar ashy shales weathering green, among which are inter- calated thin calcareous bands, extend above the lavas and coarser voleanie ashes to a point about, 200 yards below the junction of the upper tributaries of Backside Beck, namely, Spengill and Stock- less Gill. They are succeeded by grey-blue pencil slates, the normal Ashgill Shales. The beds between the volcanic group and the Ashgill Shales will be spoken of as the ‘ beds above the volcanic group.’ In Backside Beck they have yielded the following fossils :— Dicellograptus anceps. Agnostus trinodus Salt. Dicellograptus sp. Trinucleus seticornis (2). Climacograptus normalis. Ampyz. * Orthograptus truncatus var. abbrevi- Dindymene hughesie Roberts ? atus Elles & Wood. Spherocoryphe thompsont Reed. Mesograptus modestus Lapw.? Staurocephalus globiceps Portl. ? Nymphograptus (?). Skenidium. Retiolitid. Conularia. Just below the Ashgill Shales, and forming the very top of the beds above the volcanic series, about 10 feet of argillaceous limestone Vol. 69.] PALHOZOIC ROCKS OF THE CAUTLEY DISTRICT. 5 is seen in the stream-bed. It is unweathered, and I could find no fossils in it; but it probably represents an important band in Watley Gill and Oddgill, described elsewhere. The Ashgill Shales of Backside Beck are not very fossiliferous, save the bands with Phyllopora hisingert and Myelodactylus near the top. Strophomena siluriana Day., with other brachiopods, and Phacops mucronatus Brongn., are not infrequent. I believe that all records of Trinucleus from the Ashgill Shales of this stream refer to specimens obtained from lower beds, which have hitherto been partly referred to the Ashgill Shales. Before leaving the beck, I may say that I doubt the identification of Phacops brongniarti which I previously made. The specimen is unfortunately lost. To sum up, the Backside-Beck section gives us the following sequence :— ( Upper: Ashgill Shales (with Phy/lopora Beds near the top). {Beds above the volcanic | group. 2 | Contemporaneous voleani ASHGILLIAN ...4 Middle: Stawrocephalus Beds 4 Soe sce | 5 : : | Beds below the volcanic \ group. | Lower: Phacops-robertsi Beds. Carapocian ... Calymene Beds. Confirmatory Sections. Watley Gill.—Starting from the junction with Backside Beck, the Phacops-roberts: Beds are exposed for a few yards up the tribu- tary in its wooded portion, and pass up into blue flags, which are well seen opposite the sheepfold, and continue for many yards up stream. ‘I'hese are the beds below the volcanic group. They have ylelded Climacograptus normalis, with crushed brachiopods, lamelli- branehs, and phyllocarida. The contemporaneous volcanic group follows, succeeded by cal- careous shales weathering olive-green, as in Backside Beck. The latter are much penetrated by lamprophyres, and fossils are ill- preserved, with one important exception to be noted immediately. The beds do not appear to be so thick as in Backside Beck, and some are probably faulted out. At the extreme summit of these beds, above the volcanic group and immediately below the ordinary ‘ pencil-slate’ Ashgill Shales, are calcareous beds with Phacops mucronatus and abundant Cystidea. The following were found :— Caryocystites davisti M‘Coy. Phacops mucronatus. Hemicosmites sguamosus Korbes. Leptena. Hchinospherites aurantiun Forbes? Orthis. Turrilepas. Conularia (2). This deposit may be referred to as ‘the mucronatus band of the Staurocephalus Group.’ It is marked by the first appearance of “SOPIS[OF OATSN.QUT = yp ‘(URIDOpeRaep) speg auauwhjyn7g = O at "Spagy 287.ag0l-sdoony , = x7 a *9tl0}s = aie ‘SPOT DLUBITOA SNOdUBAOdINOZUOD at[} MOTEG Spog~E = ‘G"T] = ) -OWIT UBLINTIG peseq = g = sped ‘SyPOT OLuBI[OA SNOsUBAOde}UOD = °° a ‘SaTVYG eTepyooqg = 4g a0} snpnydar0unnpy 1 pe 0 @) = Hat || AMELIE ‘SYOOL O1MBOTOA snovuRdod ula}u0d ay} eACge Spag = “s'q A \'speq MoTpnyT aamoy = 7 < \ ‘d 9 spog viodopp hy YIM ‘sopeyg TpLsysy = y | ] ISueds ID $$9]349035 THD e727 aspliqyo04 qne iy O pue [[Isueds jo ynoyy poumny Ss N jo uolzoUNn (ayiu [ = sayour + + aqnos ppuozwof7) "pprbuady 0, ynng moppny oy) Mol yoagy aprsyong ur u0rp99Ig¥— J “817 Vol. 69.] LoWsR PALAOZOIC ROCKS OF THE CAUTLEY DISTRICT. 7 Phacops mucronatus, a form which extends upwards into the Ashgill Shales, and also into the Stockdale Shales. It is probably the same band as that mentioned just below the Ashgill Shales of Backside Beck: its significance will be noted later. The succeeding ‘ pencil-slate’ Ashgill Shales are quite like those of Backside Beck and other localities in the district, and contain the usual fossils. Near the top is more than one band with Phyllopora hisingeri, as in Backside Beck. Above these come several feet of normal Ashgill Shales, with Platystrophia biforata Schloth. and other brachiopods, and also several Phyllocarida. In the shales is: a calcareous grit, or possibly more than one, containing brachio- pods, and resembling the grit described by Prof. Hughes at the junction of Spengill and Stockless Gill. At that place the bed seems to be now covered up. The north-eastern dome.—The beds of this dome are much faulted, but the Caradocian strata, as a whole, occur in the centre, and are well developed in Sally Beck and its valley-sides. The beds. -are generally similar to those of Backside Beck; but, as many exposures are seen where the rocks are weathered, the fossils. here are more easily extracted. The principal localities are at. the bottom of Green Lane, east of Murthwaite, on the left banix of the beck ; and Sally Brow, near Murthwaite, on the right bank. The following fossils have been obtained, those from Green Lane being numbered 1, and those from Sally Brow 2 :— Lindstremia. 2. Proetus. 1, 2. FHleliolites tuhulata Lonsd. 2. Homalonotus sedqwicki Salt. 2 (com- Cystidea. 2. mon), Trinucleus seticornis (%). Chetrurus octolobatus M‘Coy? 2. Ampyx. 1. Phacops robertsi. 2 (two specimens). Acidaspis cf. dalecarlica Vornq. 1. Lingula. 2. Acidaspis sp. 2. Platystrophia biforata. 2. Stygina. 1. Orthis elegantula Dalm, 1, 2. Mlenus. 1, 2. Orthis vespertilio Sow. 1, 2. Cybele rugosa Portl. 1. Orthis porcata M‘Coy? 1. Cybele verrucosa Dalm. 1, 2. Plectambonites sericea. 1, 2. Calymene planimarginata. 1,2 (very | Triplesia insularis Wichw. 2. common), Tentaculites anglicus. 2. Encrinurusmultisegmentatus Portl. 2. These beds undoubtedly yield the fauna of the Calyimene Beds, but the presence of Phacops roberts: suggests that the beds of Sally Brow are high up in that group. Farther down stream the section has not been entirely unravelled. The beds begin to dip down stream, and continue with this general southerly dip until near Rawthey Bridge, where they turn over and dip north-westwards. It would, therefore, seem that, apart from complications, we are dealing with a syncline. In the southern limb, to be presently described, the succession is clear and continuous; but in the northern limb it is obscure, and we have only fossils from one locality, namely, the footbridge across Sally Beck, over which is the path to Murthwaite. Fossils were found here by Mr. Middlebrook. The 8 DR. J, E. MARR ON THE LOWER [March 1913, beds are of doubtful age, as no characteristic forms of either Ash- gillian or Caradocian strata have been found; but the lithological characters and the general nature of the fauna suggest that the beds are Ashgillian, and belong to the Stawrocephalus division. The rock is a grey encrinital limestone, weathering to an ashy-looking olive-green and brown rottenstone. It yielded :— Remopleurides. Cybele verrucosa. Phillipsinella parabola. | Phacops (Chasmops ?) sp. Lichas laxatus. Orthis (several species). Lllenus bowmanni (2). | Strophomena corrugatella (7). If the beds on Sally Brow are high up in the Calyimene Group, as suggested, the newer age of these footbridge strata is rendered still more probable. We will pass now to the southern limb of this syncline, where the ‘beds are well developed in the Rawthey, above and below the mouth of Saliy Beck. Above Rawthey Bridge, the section in the neighbourhood of the fault which lets down the Carboniferous rocks is obscure, but there is a general ascending succession down stream. Phacops roberts: was found in a cliff 100 yards above the bridge, in unctuous grey shales associated with light-coloured limestones, and the same fossil occurred under the bridge itself. About 30 yards lower down the stream, a small cliff on the left bank shows the beds in a weathered condition, and here fossils are plentiful. We found :— Turrilepas. Phacops. Two other species. Remopleurides (Caphyra) sp. 1. Orthis. Phacops robertsi (very abundant). | It is doubtful whether any of the beds up stream belong to the Calymene Group, but the fossiliferous beds just described are un- doubtediy the Phacops-robertsi Beds. Continuing down stream, on its left bank we observe a continuous exposure for a long distance. ‘The beds above described pass into blue flags, which are penetrated by a lamprophyre. These, from their position and characters, are the lower division of the Stauro- cephalus Group, but have here yielded no fossils. Nosign of the con- temporaneous volcanic rocks was seen here, apart from the general ashy appearance of the calcareous shales, and Dr. Strahan has shown that the volcanic rocks die out southwards. Above the blue flags are olive-green ashy-looking mudstones resembling the beds above the volcanic group of Backside Beck. They set in near the eastern end of the wood which skirts the right bank of the stream, aud are continued: down stream until near the western end of the wood. ‘The following fossils were found in these, the upper division of the Staurocephalus Beds (beds above the voleanic group) :— Dicellograptus anceps. Cybele rugosa var. attenuata (2). Glyptograptus persculptus. Orthis. Chimacograptus normalis. Leptend. Trinucteus bucklandi Bary. (?). Tentaculites anglicus. Dindymene hughesie (?). Vol.°69. |] PALZOZOIC ROCKS OF THE CAUTLEY DISTRICT. 9 Below the wood there is a short interval with no exposure, and then the Stockdale Shales are seen. ‘he interval seems too small to allow of a full development of the Ashgill Shales, and there is probably a fault at the base of the Silurian strata. Another development of Ashgillian rocks is found in this dome in Oddgill, a tributary of Wandale Beck north of Murthwaite. The beds here are separated from those last described by a fault, as ‘noted in the Geological Survey Memoir. | The lower part of Wandale seems to be in Caradocian strata, but no fossils have been tound. The first fossils met with were in rocks developed in Wandale Beck, 75 yards below the mouth of Oddgill. These are of the same nature as those exposed in Backside Beck and the Rawthey, and yielded :— Dicellograptus anceps. Trinucleus. Orthograptus truncatus yar. abbre- Phacops robertsi. viatus. Lingula. These deposits belong to the beds below the volcanic group. At the mouth of Oddgill, as noted in the Survey Memoir, the contempo- raneous volcanic group is seen, and higher beds are observed in passing up this gill. ‘These have the lithological characters of the beds above the volcanic group, but we obtained no fossils from them. ‘They occur in the wooded portion of the gill, where they are broken through by a large felsite sill, and continue upwards on to the moorland. Where a little stream enters Oddgill trom the north, the mucronatus band at the top of the Staurocephalus Beds is seen, having the same characters as at Watley Gill. It yielded :— Hemicosmites squamosus. Cheirurus, Kchinospherites arachnoideus (2). Phacops mucronatus, Turrilepas. Phacops (Acaste) apiculatus Salt. Above these beds, in the little tributary, is a poor exposure of leaden-blue shales, which are almost certainly Ashgill Shales. beyond this, the section is covered by drift. The south-eastern dome.—In this dome important sections are seen in aythes Gill and its tributaries. The lower part of the gill (known as Ecker Secker Beck) certainly contains Ashgillian rocks; but, before entering the moorland, Caradocian Beds are seen. These occupy the core of thedome. ‘The accompanying sketch-plan (fig. 2, p. 10) of that part of Taythes Gill and its tributaries which lies around Taythes House shows the relationship of the Caradocian and Ashgillian strata. On the right bank of the gill, just opposite the bridge leading to Taythes House, are weathered Calymene Beds containing abundantly the index-fossil. Farther down stream is a thick sill of felsite, and immediately below this are unctuous grey shales and limestones with Phacops robertst. There is not room for more than a few feet of strata between the highest beds with Caly- mene and the lowest Ph.-robertsi Beds; and so here we are able to draw a fairly sharp line between the Caradocian and the Ashgillian. 10 DR. J. E. MARR ON THE LOWER {March 1913, The Phacops-robertsi Beds are well exposed in Wraymire Gill, immediately before it joins Taythes Gill, and are here fairly fossiliferous. Hence they strike westwards to a point in Taythes Gill above a footbridge on the west side of Fairy Gill, and eastwards into Splinter Gill, where they are again seen. In all these localities they are very fossiliferous, and the following forms have been found :— Dicellograptus anceps. 2, 3. Phacops roberist. 1, 2, 3 (very Glyptograptus persculptus. 3. common). Ampyx. 3. Phacops apiculatus (/). 2. Trinucleus seticornis (2). 1, 2, 3. Phacops cf. downingie. 2. Dionide euglypta Barr.? 2. Turrilepas. 1. Remopleurides (Caphyra) sp. 1. 1,2, | Lingula. 2. 3 (very common). Orthis. 1, 2, 3. Illenus. 2. Leptena. 2. Lichas. 3. Conularia, 1. 1=Wraymire Gill; 2=Taythes Gill, west of Fairy Gill; 3=Splinter Gill. No Staurocephalus Beds or Ashgill Shales are seen in the upper part of Taythes Gill, where the Calymene Beds are faulted against Stockdale Shales; nor in Wraymire and Splinter Gills, the heads of which are filled with drift. Drift also covers the lower part of Fig. 2.—Plan of streams at Taythes, on the scale of 6 inches to the mile. A= Ashgill Shales. F=Felsite. [The letters A, P, C are placed P= Phacops-robertsi Beds. T=Taythes House. alongside arrows showing C= Calymene Beds. localities where fossils were found. | Fairy Gill, and doubtless conceals the Stwurocephalus Beds : for the well-known sections of Ashgill Shales of Fairy Gill are dipping away from the Phacops-robertsi Beds which are above described. Hence no continuous section of Ashgillian strata, like that found in Backside Beck, has been detected in Taythes Gill. Vol. 69.| PALHOZOIC ROCKS OF THE CAUTLEY DISTRICT. el B. Tue Srmurian Srrata. Stockdale Shales.—In a paper on these beds by the late Prof, Alleyne Nicholson and myself, a limestone 6 inches thick was described as occurring at the base of these shales in Backside Beck. There the Ashgill Shales are seen immediately below it; we have now found fossils in the limstone itself, and they are :— Enerinurus punctatus var. arenaceus | Leptena ef. quinquecostata. Marr & Nich, 7 Orthis, two spp. Cheivurus bimucronatus Murch. var. ? Strophomena, two spp. Phacops mucronatus. | Hypolithes. In the note communicated by Mr. Fearnsides and myself to the British Association at Sheffield in 1910, it was stated that an im- portant section of the Skelgill beds of the Stockdale Shales occurs in Watley Gill. Of this I propose to give some further details. The basal limestone just noticed is here seen badly exposed on both banks immediately above the Ashgill Shales. From it we obtained :-— Cyphaspis cf. rastritum Tornq. Phacops mucronatus. Acidaspis. Hyolithes. Above it are the shales of the Dimorphograptus Zone with badly- preserved graptolites, which, however, are sufficiently determinable to indicate the zone. ‘This is succeeded by the shales of the Monograptus-fimbriatus Zone with that fossil, JZ. cyperoides Tornq., and Diplograptus mutabilis Elles & Wood ? Above this come the hard mudstones of the Encrinurus Zone, followed by the shales of the Monograptus-argenteus Zone. The latter is much crushed, but a little thinner than in the Lake District. It contains the ‘ green streak,’ also shghtly thinner than in that district. The fossils obtained from this zone are :— Monograptus argenteus Nich. Monograptus gregarius Lapw. ? M. leptotheca Lapw. Rastrites hybridus Lapw. M. convolutus His. Climacograptus hughesi Nich. M, nicolt Harkn. Diplograptus sinuatus Nich. M. limatulus Torng. Diplograptus bellulus Tornq. M. communis Lapw. It is succeeded by the Phacops-glaber Zone, from which my son obtained a tail of that form; and above the beds of that zone are the shales of the Monograptus-convolutus Zone, from which we extracted the index-species and some of its usual accompaniments. A fault here brings up the Dimorphograptus Beds once more, and above this there is no further exposure in the gill. In the south-eastern dome the basal limestone of the Stockdale Skales occurs in Birks-Wood Gill, a little distance above the road. It here resembles the same limestone as seen in the Lake District, and contains brachiopods ; but no specimens sufficiently perfect for determination have been found. 12 DR. J. E. MARR ON THE LOWER [March 1913, Wenlock Beds.—The graptolitic succession of these beds has recently been described by Miss Watney & Miss Welch,’ and no further remarks are necessary concerning the graptolites. Other fossils are rare, save some obscure brachiopods and cephalopods ; but my son discovered the head of an Arethusina in an exposure of the Cyrtograptus-murchisoni Zone of Middle Gill. (See Appendix, _p- 16.) Lower Ludlow Beds.—Here again, the graptolitic succession has been described by the above-named authors, who note the occurrence of the Phacops-obtusicaudatus Beds. In these beds a fairly rich fauna has been discovered, including the following fossils :— Acidaspis. 1, 2. Phacops sy. 1. 1, 2. Encrinurus variolaris Brongn. yar.? | Phacops sp. 2. 1. 2. Leptena. 1, 2. Proétus. 1, 2. Orthis. 1. 2 Phacops obtusicaudatus Salt. (common | Orthoceras, various species (frequent). wherever the beds are exposed). 1=North-north-west of Narthwaite. 2=River Rawthey, below the entrance of Backside Beck. These beds are the Middle Coldwell Beds of the Lake District. It is doubtful whether the Lower Coldwell Beds are developed at Cautley. The Upper Coldwell Beds form, at any rate, part of the Mono- graptus-nilssoni Lone. They contain other fossils, such as Cardiola, but no important collection has been made from them. The Bannisdale Shales with Monograptus leintwardinensis also contain numerous fossils other than graptolites, but I have nothing to add to the lists given in the Geological Survey Memoir. There is much work yet to be done in collecting fossils from all the Lower Ludlow rocks of the district. One deposit of Silurian age may be noted, although its exact horizon has not been established. In Screes Gill, on the south- western slopes of Yarlside, Mr. Middlebrook has found beds of gritty white limestone, much contorted, but certainly many feet thick. The fossils that have been obtained are poorly preserved and do not indicate the horizon of the limestone, which is probably, however, very low down in the Lower Ludlow succession. C. RetatronsHiv oF THE ASHGILLIAN BEDS TO THOSE OF OLHER AREAS. In the first place, it is evident that the Ashgillian Series is the zone of Dicellograptus anceps. his fossil appears in the Phacops- robertst Beds and passes into the Staurocephalus Beds, being found both above and below the contemporaneous volcanic rocks. No graptolites have occurred in the Ashgill Shales. 1Q.J.G.S. vol. Ixvii (1911) p. 215. Cab ml Vol. 69. ] PALHOZOIC ROCKS OF THE CAUTLEY DISTRICT. 13 The above-mentioned graptolite has been found in the Desert- creat Beds of Tyrone.' It has also been recorded by me in the beds at Norber Brow in the Settle District.* There is no doubt that these beds are Ashgillian, and represent the Staurocephalus Beds of the Cautley District. In the Lake District, I divided the Ashgillian Series into a lower group, Staurocephalus Limestone, and an upper, Ashgill Shales.* The identity of the Ashgill Shales in that and the Cautley districts is clear, but the Stawrocephalus Limestone of Lakeland presents the lithological characters and fauna of the uppermost division only of the Cautley Staurocephalus Beds (the Phacops-mucronatus Band). The fauna of the bulk of the Stawrocephalus Beds and of the Phacops-robertsi Beds appears to be wanting in Lakeland. This may be due to an unconformity (which occurs below the Ashgillian Series in South Wales), or some of the beds referred to the Sled- dale Group may be really Ashgillian. I suspect the former, but further work is required in Lakeland. In the Cross-Fell inlier it is more probable that some of the beds referred to the Sleddale Series are actually Ashgillian. It may be noted that the Sleddale (Calymene) Beds of Cautley lithologically resemble those of the Cross-Fell inlier more than those of Lakeland ; and I suspect, from the occurrence of certain fossils high up in the Dufton Shales of Swindale Beck, that the upper part of the Dufton Shales may have to be removed from the Sleddale Group (Cara- docian) and placed in the Ashgillian. The succession in South Wales can at present be more satis- factorily compared with that of Cautley. The Staurocephalus of Pelcombe Cross is unaccompanied by Phacops robertsi, and, con- versely, the former fossil is not recorded from the Ph.-robertsi Beds of Prendergast. It would seem that the beds termed ‘ Sholeshook Limestone Group’ by the late Mr. T. Roberts & myself,* which include the above-named deposits, may be divisible into a lower and an upper series characterized by the Phacops and the Stauwro- cephalus respectively. The similarity of the higher beds in the two areas has been noted by me,’ and needs no further remark. The notes in the paper just cited also render it needless to com- ment upon the relationship between the Ashgillian Series of Cautley and that of other areas. In conclusion, the development of the Ashgillian Series in the North of England is far more satisfactorily shown around Cautley than in the neighbouring areas of the Lake District and Edenside ; and I have described this Cautley succession as one which should be taken as the type for the Ashgillian Series of Northern England. 1 See W. G. Fearnsides & others, Proc. Roy. Irish Acad. vol. xxvi, sect. b (1907) p. 111. 2 Geol. Mag. dec. 3, vol. iv (1887) p. 36. 3 Tbid. dec. 3, vol. ix (1892) p. 97. * Q. J.G.S. vol. xli (1885) p. 480. ° Geol. Mag. dec. 5, vol. iv (1907) p. 69. 14 DR. J. E. MARR ON THE LOWER [March 1913, D. Apeenptx—Nores on tHe Fossits. In the lists given in the paper, a large number of forms are queried, or compared with forms to which they present near affinities. I have no doubt that many of these are ney; but, con- sidering the fragmentary nature of the material at my disposal, I do not feel inclined to create new species. The names of the brachiopods are chiefly names which in many cases cover several forms now included in one species. With regard to these brachiopods, it is noteworthy that the large Orthides and Strophomene occur in great profusion in the Cara- docian rocks, but are rare in Ashgillian strata below the Ashgill Shales, being replaced by much smaller, often minute forms. The vague determinations are given in the lists, in the hope of directing the attention of collectors to an area which will un- doubtedly yield a rich harvest. When this is reaped, the paleon- tology of the Ashgillian Series of the area can be elucidated in detail. The peculiarly rich and well-preserved fauna of the lime- stones of the Phacops-robertsi Beds will in particular well repay prolonged search. In the meantime, the lists here tabulated will suffice to indicate the dominant forms, and show the marked differences between the Caradocian and the Ashgillian faunas of the Cautley District ; they also enable us to correlate the beds with those of other areas. All the fossils referred to in the paper are preserved in the Sedgwick Museum, Cambridge. (1) Fossils of the Calymene Beds. EcHinosPH#RITES STELLULIFER Salt.—A specimen bearing this name is preserved in the Sedgwick Museum. It was probably col- lected by Sedgwick, and is from ‘ Ravenstonedale.’ It is probable that it came from the Calymene Beds, as the other specimens col- lected by Sedgwick from this tract are from these beds. The Sally Beck basin was included in Ravenstonedale by Sedgwick, and no Ordovician strata occur in Ravenstonedale proper. Isolated plates of Cystidea are not uncommon in the Calymene Beds. One from Sally Brow closely resembles the form described by M‘Coy! as Acanthalepis jamesti, which, as Edward Forbes suggests, is almost certainly cystidean. TrInucLEUs.—See p. 15. REMOPLEURIDES (sensu stricto?) sp.—Fragments of Remopleurides have been found in the Calymene Beds of Taythes Gill and Backside Beck. An external cast showing six of the body-segments and traces of two others comes from ‘l’aythes Gill. Axis and pleura alike are ornamented with wavy lines at right angles to the length of the 1 ‘Synopsis Silur. Foss. Ireland’ 1846, p. 7 & pl. i, figs. 1-2. * Mem. Geol. Surv. vol. ii (1848) p. 511. Vol. 69. | PALHOZOIC ROCKS OF THE CAUTLEY DISTRICT. 15 trilobite. A specimen from Backside Beck is a portion of a glabella well preserved in limestone. It shows no sign of glabellar furrows. A single pleuron from this locality differs from the pleura of the Taythes Gill specimen in the direction of the lines, which are parallel to the long axis of the animal. Two species may be indicated. Puacors ropurtst Reed.—The occurrence of two specimens in the Caradocian beds of Sally Brow marks the arrival of a form peculiarly abundant in the lowest Ashgillian strata. The species is, however, obviously very rare in the Calymene Beds, for much material has been broken up. (2) Fossils of the Phacops-robertsi Beds. Trinucteus (Terraspis)—The subgenus is abundant in the Calymene Beds of the Caradocian Series and in the Phacops- roberts: and Staurocephalus divisions of the Ashgillian. I have handed over the material to Mr. F. R. C. Reed, who is at present engaged in studying the genus, and need only remark here that the somewhat imperfect specimens from the Caradocian agree with forms usually referred to 7’. seticornis. This is also the case with those from the Phacops-robertsi Beds. In these forms the fringe ends near the posterior angle of the head, and a simple spine extends backwards. In the Staurocephalus Beds a form is common which has the fringe prolonged backwards sometimes as far as the pygidium, as in Barrande’s V’rinucleus bucklandi. RemopLevRipes (CapHyra) sp. 1.—This form apparently differs from any species hitherto described. The anterior tongue is much longer than that of the form figured by Barrande, but agrees fairly with the tongues figured by Lin- narsson’ and Olin.’ The ornamentation is quite different from that on Barrande’s specimens, and also from that in pl. i, fig. 21 of Linnarsson’s paper. Head, body-rings, and tail alike are marked by wavy transverse lines; similar lines are seen in LR. portlocki, figured by Mr. F. R. C. Reed from the Tramore Limestone of Water- ford,’ and in &. latus Olin*; the other characters of the species here described are different from those of these forms. Three pygidia have been found, which, apart from the ornamen- tation, are too imperfect to show the characters. This species is extraordinarily abundant in the Phacops-robertsi Beds. \ " K. Svensk. Vetensk.-Akad. Handl. vol. viii (1869) No. 2, p. 67 & pl. i, fies. 21-22. “2 Meddelande fran Lunds Geol. Faltklubb, sect. B (1906) p. 54 & pl. ii, figs. 1-2. 3 Q.J.G.S. vol. lv (1899) p. 746 & pl. xlix, fig. 4. ep cit. pl. ii, figs. 6, 8, & 9. 16 DR. J. E, MARR ON THE LOWER [March 1913, LEMOPLEURIDES (sensu stricto) sp. 2.—Two fragments of heads from the limestone of Backside Beck, at its junction with Watley Gill, belong to this subgenus. They are marked by a very broad neck-ring. They are also marked by transverse wavy lines like those of the last form. Remoprevripges sp.—A large form occurs in beds of doubtful age, at the footbridge to Murthwaite over Sally Beck. One has eight body-segments preserved, the other nine and a fragment of the pygidium. It is interesting to note that one of two specimens found has a broad, the other a narrow, axis, as is so frequently the case with species of this genus. litmus sp.—A pygidium from Taythes Gill does not appear to agree with that of any described british species. It closely re- sembles an unnamed form figured by Prof. Brégger from the Ordovician beds of Espehoug, in the Trondhjem district.’ (3) Fossil from the Cyrtograptus-murchisoni Zone (Wenlock). ARETHUSINA sp.—The discovery by my son of a head from the Cyriograptus-murchisoni Zone of Middle Gill adds another record for this rare British form. It had previously been recorded by Mr. F. R.C. Reed from the Balclatchie Beds of Girvan.* He refers this doubtfully to Barrande’s A. konincki. In addition to that species, we know A. nitida Barr. from the Ludlow Beds of Bohemia, a pygidium only being figured; A. sandbergeri, also described by Barrande from the Devonian beds of Hagen (Westphalia) *; a form referred to A. konincki from the Retiolites Beds of Dalecarlia* ; and one described by Prof. Frech under the name of A. haveri.’ This last is a Silurian form, but its exact horizon is a matter of dispute. It comes from an Orthoceras Limestone at Kok in the Eastern Alps, which is equivalent to part of our Wenlock or Lower Ludlow Beds. Prof. Térnquist notes some minor variations between his form and the typical Bohemian konincki. Prot. Frech’s species is stated to differ from konincki by its considerably arched glabella, its rounded cheeks, the transverse furrows on the further side of the glabella (which do not reach the eyes), and the smaller margin of the head-shield. Our form resembles Frech’s (and also Tornquist’s ?) in the arched glabella; but it differs from A. haverz in having the 1W. C. Brogger, ‘Om Trondjhemsfeldtets midlere Afdeling mellem Guldalen & Meldalen’ Vidensk.-Selsk. Forhandl. (Christiania) 1877. 2 «Lr. Paleozoic Trilobites of Girvan’ pt. 2, Monogr. Palxont. Soc. vol. lviii (1904) p. 84. 3 J. Barrande, ‘ Réapparition du Genre Arethusina Barr.’ Prague, 1868. 4 §. L. Térnquist, ‘Undersékn. ofver Siljansomradets Trilobitfauna’ Sver. Geol. Undersokn. ser. C, Nu. 66 (1884) p. 51. 5 F. Frech, Zeitschr. Deutsch. Geol. Gesellsch. vol. xxxix (1887) p. 736. Vol. 69.] PALHOZOIC ROCKS OF THE CAUTLEY DISTRICT. 17 cheeks prolonged into spines, and the transverse furrows reach the eyes. Until further specimens are discovered, it will be best to leave it unidentified. (4) Phacops-obtusicaudatus Beds. Several forms of Phacops (including Dalmannites) occur in these beds. In addition to the typical Ph. (D.) obtusicaudatus are the following :— Puacors (Darmannires?) sp. 1.—A pygidium and imperfect body-ring from north-east of Narthwaite evidently belong to one species; and, from the character of its ornamentation, a head from the left bank of the Rawthey probably belongs to the same form. It is noticed here on account of the character of the tail, the border of which is not entire. Each fused segment is prolonged into a denticulate extremity, very marked in the case of the two anterior segments, but obscure in the hinder segments. The axis and limb are ornamented with rows of elongated tubercles, which, judging from the cast, were short spines. A similar ornamentation is seen on the body-ring. The form approaches Cryphwus, which, according to J. W. Salter’s diagnosis,’ differs from Dalmannites only in the character of the tail. He later comments upon ‘the folly of classifying the Trilobites by such a character as the pattern of the tail.’ It is interesting to note that Prof. E. Kayser” describes, under the name of Vhysanopyge argentina, a tail from Didymograptus- bearing beds of South America, which carries somewhat similar ‘denticulate extensions, and, in addition, a long terminal mucro. Puacops (DALMANNITES) sp. 2.—A form was recorded by me * from the Obtusicaudatus Beds of Lakeland, under the name of Ph. torvus Wyatt-Edgell. This form is common at Narthwaite. I cannot find the specimen of Ph. torvus of Wyatt-Edgell which led me to make this identification. The fossil recorded by that name in the Museum of Practical Geology is a true obtusicaudatus. Discussion. Miss G. L. Errus drew attention to the unity of the Ashgillian as regards its graptolitic facies ; she pointed out that its graptolitic fauna, though in some respects of the nature of a passage-fauna between the Bala on the one hand and the Llandovery on the other, had some distinctive characters of its own. With the advent of this fauna the many-branched Plewrograptus, Leptograptus, and the large Diplograpti, so especially characteristic of the Bala, died away; while its upper limit was defined by the incoming of JZono- grapti. She also suggested that parallelism with the classic areas ' *Monoer. Brit. Trilob.’ Palzont. Soc. (1864) p. 15. * Zeitschr. Deutsch. Geol. Gesellsch. vol. 1 (1898) p. 425. * Geol. Mag. dee. 3, vol. ix (1892) p. 537. Q.J.G.8. No. 273. c 18 LOWER PALMOZOIC ROCKS OF THE CAUTLEY DistRict. | March 1913,, of the South of Scotland was not to be expected, because the con- ditions of deposition there, in early Ashgillian times at any rate, were unfavourable to life; hence the fauna was dwarfed or stunted,. and not typical. If the conditions had been favourable, the fauna of the Dicellograptus-anceps Zone might have been found at a lower horizon. Mr. Hersurr H. Tuomas felt sure that he was voicing the feelings of all workers on the Lower Paleozoic rocks in saying how grateful he was to the Author for, in the first place, giving to Geology his Ashgillian Series, and now for this piece of work which would add still more to the value of the Ashgillian Series as a geological division. The Presrpent (Dr. A. Srrawan) referred to the admirable pioneer work which had been done by Prof. 1. McKenny Hughes. in this region. The term Ashgillian suggested by the Author had proved convenient, and had been adopted in some of the Geological Survey publications relating to South Wales. The additional precision which had been given to it in this paper was of much value. Vol. 69. } THE HAFSLO LAKE AND THE SOLVORN VALLEY. 19 2. On the Harsto Lake and the Sotvorn Vauuny (Norway). By Horace Wootnaston Moncxrron, Treas.L.S., F.G.8S. (Read November 20th, 1912.) [Puate I.] Tue district dealt with in the present. communication is situated in the North Bergenhus Amt, in Western Norway. It lies north of the main part of the Sogne Fjord and west of its innermost branch, the Lyster Fjord. An account of the locality, under the heading ‘ Lysterfjorden og Hafslo,’ will be found in the admirable paper by Dr. Reusch entitied ‘ Nogle Bidrag til Forstaaelsen af hvor- ledes Norges dale og fjelde er blevne til,’ which is provided with a summary in English." A geological map of Southern Norway by Dr. K. O. Bjérlykke will be found in his work ‘ Det centrale Norges Fjeldbygning ;’ * and another geological map, on a larger scale, which takes in the present district, has been published by Dr. Reusch.2 The map which I give (fig. 1, p. 20) is merely a sketch-map, founded on the Topographical Map of Norway, Sheet 29 B (Sogndal), with the geology sketched in from the above-mentioned geological maps. If we look at Dr. Bjorlykke’s map, we shall see a great mass of igneous rock marked at the head of the Sogne Fjord with a diagonal boundary running north-east and sonth-west. Along this boundary there is a narrow belt of Silurian and associated strata, dividing the igneous rock from a vast area of Archean gneiss, etc., which extends outwards from it to the western coast. On the Archean -area 1s a great plateau covered with perpetual snow, Jostedalsbraen, associated with many smaller snow-covered plateaux; and they have also a north-eastern and south-western trend, parallel with the Silurian belt at a distance of some 18 miles. On the south-eastern side of the snowfields we find a series of valleys with a tendency to run in a south-easterly direction at right angles to the Silurian belt. They are Morkereidsdal, Jostedal, the valley of the Vejtestrands Lake, and Sogndal. Then we find other valleys running at right angles to the above, and parallel with the Silurian belt: they are the upper part of the Lyster Fjord and the Sogudals Fjord with its allies. The Haftslo Lake at once impresses one as being of interest, for it is placed at a point where two of these lines intersect, and I will briefly trace the course of its drainage-line from the snowfield ; but first I would remark that the valleys in question are, in fact, “1 Norges Geol. Undersék. No. 32 (1901) pp. 124 & 146-152. 2 Ibid. No. 39 (1905). 3 Ibid. No. 47 (1908). 2 of hood hbowr the Hafslo Lake and the Lyster Fjord. v [ 20 ] ketch-map of the ne ls Geologica ] ao 1 4 O00 50 SHOLO.00 OD Oo” Schist Series. ry 1 ‘ly PEK XXX Cel x xxx Ix x x | mK x Seale of Miles. BE Gfx OLA fe) ii Xxx % xX Xx X XXX x % XXX xxx xX Se Te Gabbro and Various Rocks, Labradorite. eae Meanee: than Schists. x yx : xx ; el DE XEXEXEE Yi oe Xay x XA LL oan Vol. 69.] THE HAFSLO LAKE AND THE SOLVORN VALLEY. 21 each a series of depressions or hollows, many of which are partly filled with water. One of the larger Norwegian glaciers, Austerdalsbrae, descends from the great snowfield in a southerly direction into a deep valley, and other glaciers descend into a branch valley, Langedalen. Some 7 miles from the foot of Austerdalsbre, we come to a lake, Vejte- strand, which has a length of nearly 11 miles. It is, however, almost divided by two small islands at a point 3 miles fromgits outlet. The southern end of the lake is formed by a low barrier of rock which crosses the valley, a view of which is given in Pl. I, fig. 1, looking northwards: the lake being on the opposite side of the rock, which (it will be observed) is greatly rounded by ice. At one time there has been a flow of water over the western side of this barrier (left side of the view); but now the outlet from the Vejtestrands Lake is through a deep and narrow gorge cut in the rock and seen in the centre of the view. Near its lower end the road from Hafslo crosses the gorge by a bridge shown in the view, and the river flows out on the left into the sheet of water seen in the foreground. Fig. 2 in Pl. I is a view of the gorge taken from a point on the rock-barrier above the bridge just mentioned, and nearer to the Vejtestrands Lake, a part of which is seen in the distance. A large kettle-hole will be noticed on the western side of the gorge, and also a track, much out of repair, made for the use of fishermen, which gives an idea of the scale. I would point out that this gorge, with its large kettle-hole and other signs of great water-erosion, is at the outlet of a long lake; and I assume that much sand, gravel, or stones must have been used to assist the water in the erosion. Now, such material cannot have been brought down the lake by water alone; so I take it that the gorge must have been eroded when the lake was filled with ice, and probably by a river flowing under a glacier. The length of the next section of the valley is nearly a mile and a half. It extends from the rock-barrier at the end of Vejtestrand to a conspicuous mound standing in the middle of the valley. The valley of the Vejtestrands Lake runs southwards, but in the section with which we are now dealing the valley shows a tendency to turn eastwards. On its northern side are steep cliffs of granitic gneiss, and the rock is greatly ice-worn: it has also been water- worn to a considerable height above the present water-level. In this rock we find a large giants’ kettle, with a circular opening at its top. In the lower part of the kettle the rock is schistose, and there is a large hole through which one can enter the kettle. The present floor of the kettle is 12 feet below the lowest part of its lip; but, the bottom being filled with earth and stones, it may be much deeper. Internally the kettle measures 17 by 12 feet: its present floor is some height above the nearest water. It should be noted that this waterworn rock and its giants’ kettle are not in a gorge, but on the side of a valley half a mile 22 MR. H. W. MONCKTON ON THE [March 1913, wide, the opposite flank of which is by no means precipitous; and I suggest that this waterworn rock and the kettle date from a time Fig. 2.— Diagrammatic section from the Hafslo Lake to the Lyster Hjord. partly valley. S a) meee eS VSS S SiS Om 6 15 SH op Ee eet Van ood fe) Solvorn Solvorn Church Lower Cliff 00 0 S = a | Lyster Fjord eu d | | n | | The Col. il 8 furlongs a Hafslo 546 ft. Lake ein Gneilss 2 | Sea Level Seale of One Mile. 3 4 OT S when a glacier filled this part of the valley, and are due to a river which, in a more confined space than the present wide valley, either flowed through, or under the ice, or bet ween it and the rock. On the side of the valley in which we find the giants’ kettle there have been great post-Glacial landslips: masses of rock, angular and unwaterworn, now lying at the foot of the cliff and in the water beforeit. Possibly the glacier left this steep wall in an unstable condition, and when the ice melted it gave way. It is possible that the part of the valley with which I am dealing may be a deep hollow in the rock ; but, if so, it is largely filled with gravel and sand spread out like an alluvial flat and covered with peat, and, for the rest, the river which keeps to the western side of the valley for the most part, spreads out in places into sheets of water. Mounds of rock project here and there. In any case, there is a great accumulation of material which must, I think, have come down the Vejtestrands Lake when it was occupied by a glacier; it is pro- bable, indeed, that the foot of the ice stood for a time near the rock- barrier at the end of the lake, and that the alluvial flat is composed of moraine-material spread out by water in front of the ice. The end of the section of the valley that we are now consider- ing is, as I have said, a big mound which stands out in the middle of the valley. ‘The river passes round the right side of the mound, and enters the Hafslo Lake. The mound, which is partly rock and moraine, joins the land on the left or northern side of the I suggest that the glacier of which I have been speaking er Poe 23 Vol. 69. | HAPFSLO LAKE AND THE SOLVORN VALLEY. halted here, and that we have a terminal moraine piled against the rock which forms the eastern end of this section of the valley. The next hollow in the valley is that of the Hafslo Lake, which has a length of 3 miles, from west to east, and a breadth of 1 mile, from north to south. As I have said, the valley is now showing a tendency to turn eastwards; and in the mountains east of the lake there is a valley in continuity with that of the lake crossing the line of strike of the Silurian rocks and running out to the Lyster Fjord at Solvorn. As I shall show, there has formerly been a drainage from the lake in that direction; but the present outlet is in the middle of the southern shore of the lake, from which the water flows into a line of depressions parallel with the Silurian belt. (See the map, fig. 1, p. 20.) At the outlet of the Hafslo Lake the rock is augen-gneiss. The road from Hillestad to Sogndal here crosses the river flowing out of the lake, and the rock on the left side has been cut in making the road; but on the right one can see waterworn rock rising to a considerable height above the present water-level, probably produced when the Hafslo Lake was filled by ice. The lake is 546 feet above the sea, and the river from it reaches sea-level in less than 2 miles. The road follows the course of the river (the Aaroj), and the scenery is very fine. ‘The river flows into a depression or hollow 2 miles long, named Barsnees Fjord. It then passes into an almost circular depression which forms the topmost part of the Sogndals Fjord. At Sogndal we enter, through a narrow opening, the main part of the same fjord, which passes into the Norums Fjord, and then into the Nordnzs Sund opening into the Sogne Fjord 4 miles east of Lekanger. ‘This openitig into the Sogne Fjord is 14 miles from the Hafslo Lake, and the course for that distance may be said (speaking generally) to lie along the line of the Silurian belt; though, for the most part, the erosive agents have cut the valley down into the underlying gneiss. Having now dealt with the existing line of drainage from the Jake, I proceed to describe the disused line of drainage from the lake to the Lyster Fjord, which crosses the line of the Silurian belt at right angles; although the valley from the lake to Solvorn has been wholly cut down into the gneiss. Fig. 2 (p. 22) is a diagrammatic section from the lake to Solvorn.! The eastern side of the Hafslo Lake is formed by a rock-barrier, in which there is a notch or col: this col is about 100 feet above the lake, and at the head of the Solvorn Valley. The rock is much rounded and iceworn, and if it be examined on the Solvorn side evidence will be found that a river flowing from the lake has passed over it. This is at the point where the Solvorn road leaves the Hillestad—Sogndal road. 1 Dr. Reusch gives an ideal view of the locality in Norges Geol. Undersok. No. 32 (1901) p. 147. 24 MR. H. W. MONCKTON ON THE [March 1913. If we look at the col from the Solvorn side, looking towards the lake, we see a high cliff with a flat marshy field at its foot. On the face of this cliff there are marks of the former existence of a large waterfall; but no water flows there now, nor can it do so again unless the ice should advance and once more fill the Hafslo Lake, up to at least the level of the col. A littie nearer Solvorn we come to another big step downwards (marked ‘ Lower Cliff’ in fig. 2, p. 22), and here once more recur signs of a big waterfall. Again we see a flat at the foot of the cliff with fields and woodland ; and I may mention that in one of the woods there is a small standing stone or bautasten, with ome stones around it, a relic of early times. The iceworn rock shows clearly that a glacier has flowed once or possibly often down this valley; but up to now we have seen very little moraine-material. We soon, however, find it in plenty ; in fact, a vast mass of sand, gravel, and stones large and small occupies the lower part of the Solvorn Valley almost to the edge of the fjord. I suggest that the foot of the ice halted for a considerable time in the space between the ‘Lower Cliff’ and Solvorn (see fig. 2, p- 22) and that the sand and gravel, as well as some big boulders which are seen here and there, are in fact the terminal moraine of this glacier. ‘This sand and gravel form a terrace, the surface of which is for the most part cultivated, and Solvorn Church and many houses stand upon it. It slopes rather steeply towards the fjord, with small level flats in places. The new road from Solvorn to Hafslo at first follows a rather deep valley, cut in this terrace by an existing stream which has a drainage-area independent of the Hafslo Lake, from which we are now at some distance. Half a mile from the fjord the road ascends the side of the rock-valley by a series of zigzags; and on the north of the road opposite these zigzags there is a pit in the terrace which affords a good section, showing sand and small gravel, well and evenly stratified, with a high dip towards the fjord. This stratification proves deposit in water which must have been the water of the fjord; and, if I am right in thinking that the terrace-deposit is a terminal moraine, the evidence shows that the foot of the ice rested here at a time when the sea stood at a level of at least the top of the terrace, estimated by Dr. Reusch as being 426 feet above the sea. I know little to show the date of the rock-valleys of which I have been speaking, but am inclined to think that the Solvorn Valley,. which belongs to the series at right angles to the Silurian belt, is probably older than the valley which runs from the Hafslo Lake to Sogndal, etc., along the line of the Silurian rocks. However . that may be, it is Clear that the moraine-material at Solvorn was. brought across the Hafslo Lake by ice, and was placed in its present position at the time when the sea-level stood 426 feet higher than now. The topmost marine limit shown by the terraces increases as we go inland from the mouth of the Sogne Fjord; that is, from west Quart. Journ. Geox. Soc. Vor. LXIX, PL. |. Fig. |. WiEW OF THE ROCK-BARRIER AT THE SOUTHERN END OF THE VEJTESTRANDS LAKE, LOOKING NORTHWARDS. H.W.M., Photo. Fig. 2. GORGE WITH BIG POTHOLE AT THE SOUTHERN END OF THE VEJTESTRANDS LAKE, LOOKING NORTHWARDS. H.W. M PF Ph oto. Bemrose, Colo. Derby. Vol. 69.] HAFSLO LAKE AND THE SOLVORN VALLEY. 25: to east. In the map given by Dr. Rekstad’ he marks the height as 328 feet a little to the west of Balestrand. In a later work” he places the late-glacial marine limit at 377 feet at Vik, on the south of the Sogne Fjord; and in another paper’ he says that the highest terrace at Hovland on the Aardals Fjord (449 feet) apparently represents the highest marine limit after the Ice-Age. Hovland (Natviken) is 15 miles south-east of Solvorn, so this agrees very - well with the 426-foot terrace at the latter place, and it clearly belongs to this late-glacial series. This late date for the Solvorn terrace, together with other evidence, makes it difficult to believe that the outlet of the Hafslo Lake to Sogndal did not exist at the time of the deposition of the Solvorn moraine. Thus there isa series of ice-markings on the rock by the new road from Marifjeren to Hillestad, a little north of the latter place, and they point in a south-westerly direction : that is, towards the present outlet of the lake and not towards the: Solvorn col. Moreover, there is evidence that a vast mass of ice passed down the series of fjords from Sogndal to the Sogne Fjord, for there are deep glacial groovings on Nordnes, south of Norum Church. I would suggest that, the Hafslo Lake being full of ice, the main glacier coming down the Vejtestrands Lake and a tributary down from the mountains north of Hillestad, and the main mass of ice moving down to Sogndal and the Sogne Fjord, there was an over- flow of ice and water from the left side of the glacier over the Solvorn col and down towards that place. This view is supported by the presence of masses of moraine-material on the mountain- side above the shore of the Hafslo Lake, between the Solvorn col and the Sogndal outlet. There is no reason why more than one stream should not flow simultaneously from a single glacier; in fact, that is precisely what happens in the case of small recent glaciers, and the fact that the Solvorn col is 100 feet above the Sogndal outlet does not, I think, make a serious difficulty: for one river may have flowed in or over the ice, and the other beneath it. In any case, I think it more probable that both outlets were used during the late-glacial period and possibly simultaneously, than that the Sogndal outlet has been deepened as much as 100 feet since the deposition of the Solvorn mass of sand and gravel. EXPLANATION OF PLATE I. Fig. 1. View of the rock-barrier at the southern end of the Vejtestrands Lake, and of the gorge in it through which the river issuing from the lake- flows; looking northwards. . Gorge, with a big pothole, at the coulhesa end of the Vejtestrands. Lake ; looking northwards. 1 Bergens Museums Aarbog (1906) No. 1. 2 Norges Geol. Undersék. No. 53 (1910). * Ibid. No. 43 (1905) p. 48. 26 THE HAFSLO LAKE AND THE SOLVORN VALLEY. [March 1913, Discussion. Dr. J. W. Evans congratulated the Author, not only on the excellence of the photographs that he had shown, but also on the clearness with which he had placed before his audience the problems in glacial geology presented by the district. The Author's sug- gestion that some of the lake-basins had been eroded by sub-glacial streams was similar to that brought forward by Werth to explain the formation of the depressions in morainic material. These depressions, which are now filled by the sea, are, according to Werth, known in Schleswig-Holstein as fohrden, in Sweden as fjiirde, and in Denmark as fjorde, which are not to be con- founded, of course, with the fiords of Western Norway. ‘The traces of a former waterfall in the disused outlet appeared to the speaker to be such as would be caused by a merely temporary out- flow in that directlon. Dr. A. P. Youne thought that the possible action of waterfalls issuing from the glaciers themselves should be borne in mind, when considering the erosion which has taken place at the end of a glacier. Mr. G. W. Youne asked whether the Author considered the transverse or the longitudinal set of valleys to be the older, and also what were the causes that he suggested to account for the diversion of the drainage into its present course. The AvrHor, in reply, stated that those valleys which ran at right angles to the strike of the sedimentary rocks were the older, and that he attached greater importance to the action of water flowing under the ice than was usually attributed to it. Vol. 69.] |‘ LRILOBITE FAUNA OF THE COMLEY BRECCIA-BED. 27 3. The Tritosite Fauna of the Comtey Breccra-Bep (SHROPSHIRE). By Enear Srerztine Copsorp, F.G.S. (Read December 4th, 1912.) [Puares II & III.] ConTENTS. Page iielin rode tiqmaseit teenilestee thease cicsaeaaar ete aeetese nee te 27 il. Recapitulation of Previous Observations ............ Pat MED eseription- of thevErilobites!..2..2s2-0-+seses.s0+0-+= 28 IV. The Stratigraphical Horizon of the Breccia-bed... 39 Weslinterencess ra yetn.is arcane ususte caseeatbssedelensedenaselns 40 Wali @onclusionspesss-avecaicaucsesescn aenseeeciee ooieecisascncs 4] I. Introduction. In a report to the Dundee Meeting of the British Association (1912) upon the excavations made in the Cambrian rocks at Comley during 1911, I called attention to a Paradoawides fauna, which appears to be new to the district, and is found in the matrix of a remarkable breccia near Comley Brook. The objects of the present paper are :— (1) To figure the trilobites of this breecia-bed, and to describe those species which appear to be new ; (2) To discuss the paleontological horizon in the Cambrian System which they indicate; and (3) To consider some inferences that may be drawn from the occurrence of this fauna in its present position among the rocks of Comley. II. Recapitulation of Previous Observations. In order to make clear the special significance of the fossiliferous Breccia-Bed, it is necessary to recapitulate some of the observations already published. In the section of the Quarry Ridge,’ the Giroomit Fauna is found in the matrix of a conglomeratic grit which rests upon the Lower Cambrian limestones that yield the Protolenus-Callavia Fauna.” A similar conglomeratic grit is found at Robin’s 'ump* with some of the same fossils; but in this case it rests, with visible unconformity, on bedded green sandstones, which are regarded as lower in the Cambrian sequence than the Protolenus-Callavia Limestones. The conglomeratie nature of the grit is easily recognized, for the matrix consists largely of rounded quartz-grains with a liberal sprinkling of glauconite, and the included blocks are either pieces ? Rep. Brit. Assoc. 1908 (Dublin) 1909, pp. 254, 256: Excavations Nos. 1 & 2. 2 E. 8. Cobbold, Q. J. G. S. vol. Ixvii (1911) p. 297. 3 Rep. Brit. Assoc, 1910 (Sheffield) 1911, p. 117 ; cb¢d. 1911 (Portsmouth) 1912, p. 111 & fig. 1, p. 112. 28 MR. E. S. COBBOLD ON THE TRILOBITE FAUNA [March 1913, of green sandstone of much finer grain or of limestone containing fossils of the Protolenus-Callavia Fauna. In most cases these fossils belong to the Bellimarginatus group. of that fauna, although sometimes they may belong to the Helena group.’ At a point near Comley Brook,’ within 300 yards of the Quarry Ridge, the Breccia-Bed, the trilobites of which are described in the present paper, rests upon solid and regularly-bedded green sand- stones of the Lower Cambrian. The breccia is composed of blocks and chips of green sand- tone (both fossiliferous and barren) and of pinkish limestone, the fossils including many of the species of the ‘ Helena group’ of the Protolenus-Callavia Fauna, and, apparently, of no other group. The matrix of this breccia consists of comminuted fragments of the same materials, and has consolidated to a green sandstone ot very much the same aspect as the parent rock. ‘This matrix varies a little from point to point in the bed, in places becoming some- what coarser and having some admixture of quartz-grains, in other places becoming more calcareous and sometimes fine-grained. It is from this matrix that the new Paradowxides fauna has been collected. Fortunately, before the Breccia-Bed was opened up, many fossils of the Helena group, embedded in a band of the Lower Cambrian green sandstones, had been found at Excavation No. 47 in the bed of Comley Brook,’ and it is abundantly evident that the breccia is largely made up of fragments of these fossiliferous green sand- stones. Previously, the fossils of the Helena group had been found only in the well-known red Olenellus Limestone of Comley Quarry ; now they have been found in the green sandstone, which forms the main body of the Lower Cambrian of the district, but there is no evidence available at present indicating to what depth below the Olenellus Limestone they descend. The thickness of the Breccia-Bed is about 5 feet; it rests immediately upor the well-bedded Lower Comley green sandstone, without any sign of faulting along the surface of junction; its upper limit, however, is probably a faulted one. It is succeeded above by brownish shale, which apparently belongs to another horizon of the Middle Cambrian. III. Description of the Trilobites. Paradoxides Brongniart. The matrix of the Breccia-Bed is plentifully charged with fragments of Paradoxides, which indicate an undescribed form, possessing characters in common with several well-known species. ' K. 8. Cobbold, Q. J. G.S. vol. Ixvii (1911) pp. 297, 298. = Rep. Brit. Assoc. 1912 (Dundee) (in the press), Excavation No. 49. 3 Tbid. Vol. 69. | OF THE COMLEY BRECCIA-BED. 29 PaRaDOXIDES INTERMEDIUS, sp. noy. (Pl. II, figs. la-le, 3 & (?) figs. 2, 4-11 c.) Paradowides cf. hicksiit Salter & sjégreni Linnarsson, and Paradowides ct. rugulosus Cobbold, Rep. Brit. Assoc. (Dundee) 1912. The type-specimens are numbered |[ 1828, 1832].’ Cranivium: Pl. II, figs. 1, 3, and 4. Dimensions in millimetres :— TONGUE NY ab dotsotide anes epaciac ese cRnees cores Aan eeaara aman nee ae 24 Width across anterior angles ................e0.0.ceceee ee eee 28 Width across eye-lobes .............00pecsceenceeeceeeeeeeeees 29 Width across posterior angles............s.cc.ceececceeeveeees 28 Length of chord of eye-lobe.............0.:sceceecececeneseneee 10 Length of do. do. and ocular ridge together... 123 General form.—Quadrate, with deep notches in front of the “eye-lobes. General convexity.*—About 1: 4. Glabella.—Moderately convex; circularly rounded in front ; widest at about a third of its own length from the front; narrowing to about two-thirds of this width at the occipital ring with four pairs of furrows, of which the anterior is situated at the widest part and is short and rather indefinite, the second is some- what longer (but also weak), the third is strong at the sides, but is rarely traceable across the axial line: all three pairs are disconnected from the axial furrow, while the fourth pair connects with it, is strong at the sides, and is continued across the axial line as an ill-defined shallow hollow. Occipital furrow.—Straight and well-marked, except in the middle third, where it is somewhat ill-defined. Occipital ring.—Wider in the middle than at the sides, so that the border projects strongly backwards. Axial furrow.—Very little impressed. Fixed cheeks.—Convex ; highest near the glabella; marked diagonally, from the end of the occipital furrow towards the middle of the eye-lobe, by a change of curvature. ‘his diagonal mark is ‘seen in two specimens, but may be due to accidental damage before fossilization. Eye-lobe and ocular ridge.—Long and wide; extending from the postero-lateral furrow to the glabella; gently convex; separated from the fixed cheek by a distinet but lightly-impressed ihne. Postero-lateral border.—Furrow narrow, straight, and but little impressed ; marginal fold wide and gently convex. Front.—A gently convex fold curves round the front of the glabella, and is separated from it by a shallow groove; both become -gradually less marked as they are followed towards the facial suture, 1 The numbers in square brackets are those attached to the specimens in my collection for the Excavations Committee of the British Association. 2 That is, the ratio of the maximum height of the glabella to the maximum avidth of the shield, 30 MR. E.S. COBBOLD ON THE TRILOBITE FAUNA [March 1913, where the fold increases to about double its original width ; between this, the glabella, the facial suture, and the ocular ridge i is a rhomboidal flat space. Facial suture.—Anterior branch curving rapidly outwards from the eye-lobe to take a course almost exactly at right angles to the axial line, until it reaches the marginal fold : here it turns abruptly forwards, and passes to the front border parallel with the axial line. Posterior branch short, sigmoidal, and extending outwards to about the same distance as the eye- lobe. Doublure.—In one specimen the upper part of the marginal fold is broken away, disclosing the cast of the doublure; it is as. wide as the maximum width cf the upper part of the fold, and is distinctly more convex. Test.—The specimens on which this description is based are internal and external casts in sandstone that is too coarse to preserve any fine surface-markings. One or two fragments. associated in the same rock, and probably belonging to the same species, have parts, at least, of the surface covered with fine granu- lations set well apart one from the other (see PI. II, fig. 10 e,-which, however, is taken from the axis of a pygidium). The doublure is furnished with a number of raised lines sub-parallel to the margin, and slight traces of similar lines have been detected on the upper part of ‘the marginal fold. The free ghieele [1435] (Pl. II, fig. 2) and the hypostoma [1449] (fig. 5) were found in the same rock-bed; the latter is of the type of that of P. bohemicus Boeck and P. tessini Brongn., but seems proportionately narrower, and the border between the two. posterior hooks is strongly curved. ‘The width shown in the figure is necessarily an approximation. THorax: (?) Pl. II, figs. 6-8. The thoracic segment (fig. 7) has unfortunately been broken up. It is remarkable for the narrowness of the axial portion in pro- portion to the spread of the pleurz (it apparently occupies only a fifth of the total width), and also for the curved hook-like termination similar to that of Paradoaides bohenvicus var. salopiensis Cobbold, from Neve’s Castle. The fragment [1455] fig. 8 appears to be part of one of the most posterior pleure. Pyerpium: (?) Pl. II, figs. 9-11.—Up to the present only one form of pygidium has been found in the same rock-bed as that which has yielded the cranidia ; there is little doubt that it belongs to the same species. It varies a little in contour, but is always nearly circular. In general form it is like that of P. hickszi from South Wales, but shows only one feebly-marked annulation of the axis (apart from the articulating facet). Linnarsson’s figure of the pygidium of P. sjogreni is very like the Comley form, but it is more quadrate. The surface-characters, shown in one specimen [1445], consist of very fine raised lines near the border (fig. 10d) and minute granules standing well apart one from the other on the axial lobe (fig. 10). Vol. 69.| OF THE COMLEY BRECCIA-BED. 3h Comparisons with other Species. Paradoxides intermedius simulates the three forms P. hicksit, its variety palpebrosus Linnarsson, and P. sjégreni, in the weakness of the glabellar furrows along the axial line, but differs in the course of the facial suture, and consequently in the general form of the cranidium, and also in the outline of the glabella. In both these characters and in the length of the eye-lobe it approaches P. rugulosus and the American allies of that species : namely, P. eteminicus Matthew and P. acadicus Matthew ; but the transverse course of the facial suture and the obsolescence of the elabellar furrows on the middle line at once differentiate it, as also does the shape of the pygidium, if the examples figured really belong to the same species as the cr anidia. The proximity of Excavation No. 49 to Comley Quarry, where P, groomvi Lapworth is found, and the proportion of 1:5 that obtains equally in the thoracic segment assigned’ to that species and in the segment now figured (PI. II, fig. 7), necessitate a comparison between the two species. Both have glabellar grooves that are weak and almost evanescent on the axial lines, and the domes of the glabellas were probably of the same rounded form ; but P. groomi of the Quarry is much larger, it hasa very markedly smooth test, a wider hypostoma with the posterior border straight for the greater part of its length, and a very characteristic nether surface to the free cheek. Fragments of this characteristic surface are abundant in the fossiliferous clots of the Quarry-Ridge Grits, and it would indeed be remarkable that they should be absent from the Breccia-Bed, if the two species were identical. The form which I have figured” as Paradowides sp. indet. No. 2 resembles P. intermedius in the long and wide eye-lobe, and in the short posterior branch of the facial suture; the surface-characters of the pygidia are akin though not identical, but their external forms are quite different. Locality and horizon.—Excavation No. 49, near Comley Brook: from the matrix of the Breccia-Bed. Agyaulos Corda. AGRAvLos sp., cf. ARIONELLUS QUADRANGULARIS Whitfield. (PI. I, figs. 15 a-15 c.) R. P. Whitfield, Bull. Amer. Mus. Nat. Hist. vol. i (1881-86) p. 147 & pl. xiv, fig. 8. C. D. Walcott, U.S. Geol. Surv. Bull. No. 10 (1884) p. 48 & pl. vii, fig. 1. A. ae Grabau, Occasional Papers, Boston Soc. Nat. Hist. vol. i (1900) No. 4. t. 3, p. 674, pl. xxxiv, figs. 9-10 & pl. xxxy, fig. 1. E.S. Pckiela, Q. J.G.8. vol. Ixvii (1911) p. 292, pl. xxv, figs. 13, 14, & ? 15. Two fragmentary specimens [1395, 1397] are very like the form figured * from the Davidis Zone of Comley. 1 EH. S. Cobbold, Q. J. G. S. vol. Ixvii (1911) p. 284 & pl. xxiii, fig. 6. 2 Id. ibid. pl. xxiv, figs. 3-6. 3 Id. ibid. pl. xxv, figs. 18, 14, & ? 15. 2 MR. B.S. COBBOLD ON THE TRILOBITE FAUNA | March 1913, Subgenus Strenuella Matthew ? AGRAULOS (STRENUELLA ?), spp. det. (PI. II, figs. 12 a—-14c.) Several fragments of cranidia [1398, 1847, 1878 c], with strongly- marked features, a large and prominent glabella, but with only a medium-sized eye-lobe, suggest a reference to Matthew’s subgenus ; in two specimens a strong nuchal spine, projecting horizontally - backwards, may be noted. Conocoryphe Corda. Subgenus Conocoryphe, sensu stricto, Gronwall, 1902. ConocoryeHe (C.) quatis Linnarsson. (PI. III, figs. 18 a-18c.) G. Linnarsson, Sver. Geol. Undersékn. ser. C, No. 54 (1888) p. 25 & pl. iv, figs. 12-15. K. A. Grénwall, Danmarks Geol. Underség. ser. 2, No. 13 (1902) p. 92 & pl. i, fig. 22. Six cranidia [1393, 1838, 1842, 1843, 1868, 1869] from the Breccia-Bed are apparently identical with Linnarsson’s species. They are in very close agreement with his figures and descriptions, but the matrix of the bed is too coarse to preserve any delicate markings on the surfaces of the casts. In the specimen figured the missing parts, shown in outline, are restored from the external impression: but one pair of glabellar furrows is visible; the ‘ ocular ridge’ is faintly traceable for a short distance only across the cheek; and in the view from above the facial sutures appear to be nearly straight. The convexity ratio is 1; 3:7. ‘ConocoryPHE (C.) Buro Hicks. (PI. III, figs. 17 a-17c.) 1865. J. W. Salter, Rep. Brit. Assoc. (Birmingham) p. 285. 1868. J. Me ae & H. Hicks, Q. J. G.S. vol. xxv (1869) p. 52 & pl. ii, Four specimens of cranidia [1388, 1391, 1844, 1845] from the Breccia-Bed are referable to this species. They are preserved as internal and external casts, but the latter are the more fragmentary. One specimen [1391] is so much distorted that its proportions cannot be made out; but the external cast is valuable, as giving indications that the surface was strongly granular or tuberculate. The figured specimen [1388], which is practically complete, differs a little from the type as described and figured by Hicks. It has a proportionately larger and less tapering glabella, the triangular boss of the anterior margin does, not reach so far back, and the glabellar furrows are not very clearly marked. The length of the head-shield is about 13 millimetres and the convexity ratio is about 1:4. Other specimens measure 10 and 4:5 mm. in length of head-shield. The shield figured in Pl. IIT has suffered a curious distortion before fossilization, parts of the left cheek and posterior margin u ” Vol. 60. OF THE COMLEY BRECCIA-BED. Oo 9 having been sharply buckled, but without actual] fracture. A somewhat similar distortion is indicated in Linnarsson’s figure of Conocoryphe exsulans.. In both instances the test appears to have possessed a considerable amount of flexibility. Subgenus Liocephalus Gronwall, 1902. Conocorypue (L.) imerussa Linnarsson. (PI. IIT, figs. 16 a—16 c.) 1879. G. Linnarsson, Sver. Geol. Undersékn. ser. C, No. 35, p. 20 & pl. ii, figs. 29-30. 1902. K. A. Grénwall, Danmarks Geol. Underség. ser. 2, No. 18, p. 101 & pl. i, go, 25, g. A single cranidium, which is practically complete [1384], is closely in agreement with Linnarsson’s description and figure, and may confidently be referred to his species from the Hxsulans Limestone of Andrarum. The specimen is preserved as an internal cast, with portions of the test adhering. ‘There are very faint traces of the ocular ridge and the associated radiating lines, but no indication of the oval tubercle on the line of the axial furrow, which is mentioned by Linnarsson ; otherwise his description applies well to the Comley specimen. Its convexity ratio is about 1:4. Linnarsson compares his species with C’. lyelli Hicks ~ (as figured, not as described). The South Wales species has, apparently, very distinct glabellar furrows and a strongly-marked ocular ridge; in these respects it differs from the Comley specimen. The form C. emarginata var. longifrons * seems to be somewhat intermediate in character between the Comley form of C. impressa and the Swedish C. emarginata Linnarsson. The specimen in question is one of the few Middle Cambrian fossils from Comley that arein a state of preservation similar to that of the majority of fragments of the Lower Cambrian Callavia and its associates. The test is partly weathered to a soft chalky- white substance that is easily removed, although in the portions lying deeper in the rock-fragment it is sufficiently hard to preserve the surface-characters. Dorypyge Dames. DoryryGeE REricuLata, sp. noy. (PI. III, figs. 1 a-15.) Dorypyge sp. with reticulate test, Cobbold, Rep. Brit. Assoc. 1912 (Dundee). Some twenty head-shields and seventeen pygidia from the Breccia-Bed, with four hypostomas, form the material to hand illustrating this species. The specimens taken as the types are as follows :— Cranidia [1407, 1411, 1882, and 1886]; hypostomas [1535, 1812, and 1814]; pleura [1419 and 1472]; pygidia [1454, 1472, 1819, and 1819]. ’ Sver. Geol. Undersékn. ser. C, No. 35 (1879) pl. ii, fig. 21. 2 H. Hicks, Q. J. G. 8. vol. xxvii (1871) pl. xvi, figs. 1-7. 3 B.S. Cobbold, Q. J. G. 8. vol. lxvii (1911) p. 286 & pl. xxiv, figs. 8-13. See G. s. NO. 273. D 34 MR. E. S. COBBOLD ON THE TRILOBITE FAUNA [March 1913, Cranipium: General form.—Irregularly pentagenal, with the front angle rounded, the base somewhat three-lobed, and the sides contiguous to it a little irregular. General convexity.—In the smaller specimen [1886] (fig. 3) the ratio is 1: 2°7, Size.—Varying from 2°5 to 20 millimetres in length. DIMENSIONS OF TIRED SPECIMENS IN MILLIMETRES, { | es | | Number of specimen ......+0.... [1407] | [1411] | [1886] | Length, omitting the spine ...... ........ 19 ca, 15 6 Width across posterior angles ............ 28 ca, 22 8&5 Width across eye-lobes ..........00.00...05- 25 ca. 19 i | Width across anterior angles ............... 22 ca. 17 65 | { A comparison of these three sets of measurements proyes that the crushed specimen [1407] has given way vertically, and has not been materially widened by pressure, except possibly at the anterior angles. Glabella.—Strongly convex; highest at about the middle of its length, widest at a point somewhat in advance of this; with sides nearly straight posteriorly ; apex well rounded and reaching the front marginal fold ; without actual furrows, but their positions are indicated by the absence of rugosities on the exterior (see . 39). : Occipital furrow.—Wide and rather deep. Occipital ring.— About an eighth of the length of the shield, exclusive of the spine; armed with a rather short spine rising from the upper surface of the ring, and directed upwards and backwards. The specimen [1882] (Pl. III, fig. 2), from which the spine came away during development, shows the impression of the doublure or nether side of the ring. Axial furrow.—Very strongly marked in the internal casts [1407, 1886] (Pl. ITI, figs. 1 & 3); but narrow and only slightly impressed on the exterior [1411] (fig. 5). Fixed cheek.—Trapezoidal; about half as wide as the glabella at a point opposite to the eye-lobe; highest close to the axial furrow; moderately convex towards the eye-lobe, strongly convex both forwards and backwards. Ocular ridge.—Absent. ; Eye-lobe.—Situated so that the anterior end is opposite the middle of the length of the cranidium ; about a quarter as long as the glabella; with a depressed crescentic area and a decidedly raised and rounded margin (PI. IT], fig. 5). Postero-lateral border.—Consisting of a strong marginal fold and a wide groove, both of which lose force towards the facial suture; strongly convex downwards, almost geniculate, from a Vol. 69.] OF THE COMLEY BRECCIA-BED. 30 point about two-thirds out from the glabella; extended laterally to a greater distance than the eye-lobe. _ Front.—Rounded at the apex of the glabella, but almost straight from it to the sutures; consisting of a narrow marginal fold, separated from the glabella and cheeks by a sharp and narrow groove; towards the sutures both fold and groove widen and tend to die away. Facial suture.—Anterior branch, as seen from above, almost parallel to the axial line, but curved inwards at its termination to join the anterior margin tangentially. Posterior branch strongly divergent, but also curving inwards at its termination to join the posterior margin tangentially. Free cheek.—When attached to the cranidium, the free cheek would be foreshortened in width, and show but a small area in the view from above (PI. III, fig. 1 a); but, as seen lying in the rock (figs. 6 & 7), it is nearly as wide, opposite the eye, as the fixed eheek. It consists of two parts sub-equal in width: (i) an inner convex area concentric with the eye, and (i1) a wide, convex mar- ginal fold, which is the continuation in an expanded condition of the front marginal fold of the cranidium; the two parts of the free cheek are separated by a wide but ill-defined hollow, which connects the anterior and posterior marginal grooves of the crani- dium ; the genal angle is produced to form a rather short spine, about half the length of the outer border of the cheek ; in conse- quence of the curved course of the posterior termination of the facial suture, a sharp point is left on the cheek between the suture and the base of the spine, Test.—The surfaces of the glabella and cheeks are covered with .a bold pattern of reticulate, raised lines, beautifully shown in the specimens retaining the test [1882, 1411] (Pl. III, figs.2 & 5), No trace of this is seen on the internal casts, but on the external casts the same pattern is often traceable as a network of impressed lines, enclosing roughly hexagonal, or rounded prominences (fig. 1 ¢). On the sides of the glabella the reticulations tend to become parallel with its margin, and are interrupted at the places where the glabellar furrows might be expected to occur (fig. 2). On the marginal fold the reticulations are elongated, and give rise to a system of -anastomosing raised lines (fig. 5). The furrows appear to be smooth. Hypostoma (PI. III, figs. 8, 9a, & 96).—Four fragmentary examples of hypostomas from the same rock-bed may be referred to this species [1535, 1812, 1813 and 1816, 1814 and 1815]. In general form the hypostoma is rather closely comparable to that of Olenoides ellsi Walcott?; but the points of the wings are set farther back. The body of the hypostoma is very convex and of an elongated oval form, about twice as long as wide, and a little narrower 1 10th Ann, Rep. U.S. Geol. Surv. 1888-89 (1890) pp. 643, 644 & text- fig. 669. Dp 2 36 MR. E. S. COBBOLD ON THE TRILOBITE FAUNA {March 1913, posteriorly than anteriorly! ; the oval is surrounded by a convex border, which expands at the sides into pointed and somewhat flattened wings. The width across the points is nearly or quite as great as the total length of the hypostoma. The border is traceable forwards as a narrow rim reaching the anterior end, where it appears, from the specimens, to be bent upwards at the margin. The postero-lateral angles are damaged in all the specimens: it is, therefore, impossible to say whether they were furnished with hooks. About half-way between these angles and the points of the wings there is a little projection on each side. The convex body is covered with a close-set network of raised lines, which are modified on the border and wings to linear rugosities, parallel to the margins. No maculee have been detected, nor any division of the convex body, such as is shown and described by Walcott for Olenoides ells?. Trorax (Pl. ILI, figs. 10-12 & 15).—Only detached pleure, and one complete but small thoracic segment, have been found. A xis.——Convex, probably spinose, or haying a pointed node. Pleurz.——-Short and wide; abruptly bent downwards about half— way out; with a wide groove and strong anterior and posterior: ribs ; the anterior rib is prolonged to form a short rounded spine, which is directed rather strongly backwards; the posterior rib curves forward at its termination to join the anterior at the base of the spine. The spines of some pleurs (the anterior?) are shorter than those of others; in front of the outer part of the anterior rib there is a flattened shoulder-like expansion, or facet for enrolment. Pyeiprum (PI. III, figs. 18-15).—-The pygidia vary much in size, one being but 2°5 millimetres long, others measure 4 to 5 mm., and yet other fragments indicate a length of 16 mm. General form.—-Approaching a semicircle; convex: the con- vexity ratio of one small specimen being about 1: 4. Axial lobe.—Very convex; about a third of the total width of the shield anteriorly, but tapering backwards to the rounded ex- tremity; reaching to the inner margin of the border; divided by six” grooves into—the anterior articulating facet, four subequal divisions, one shorter division, and the somewhat bulbous and rather longer terminal division; the last groove is much less distinct than the others; the descent to the border is but mode- rately steep; there are no spines or nodes on any of the divisions. Lateral lobes.—-Sub-triangular ; moderately convex ; marked by four distinct furrows, with intermediate flattened ribs between them ; sometimes there are traces of fifth and sixth furrows pos— terior to these; the anterior rib is narrow and well rounded, and is traceable across the border. Border.—Continuous round the sides and end of the pygidium ; 1 The terms anterior and posterior are used here in accordance with the actual position of the plate when attached to the head-shield. 2 In the restoration (Pl. III, fig. 15) one of these grooves has been omitted. Q= Vol. 69. ] OF THE COMLEY BRECCIA-BED. 37 flat, and having a width equal to about a seventh of the length of the shield, omitting the spines; armed on each side with six spines, which are somewhat hooked at their terminations, and decrease in size from front to rear: in front of the anterior rib of the lateral lobe where it crosses the border there is a shoulder- like expansion or facet; posteriorly, and immediately upon the axial line, the border is crossed in the smaller specimen (PI. III, fig. 15) by a slightly raised riblet, a very faint trace of which is also to be detected on the largest [1819] (fig. 15). Test._-No specimen of the pygidium is sufficiently well pre- served to show the surface-characters. The species differs from the other form of the genus from Comley (Dorypyge lakei Cobbold)*: (1) in having arather longer eye-lobe ; (2) in being proportionately wider across the posterior angles of the cranidium ; (3) in the surtace-characters; (+) in the proportionate length of the spines; (5) in the presence of pleural facets, no traces of which have been detected in D. lakei; (6) in the more tapering axis of the pygidium ; (7) in the absence of spines on that axis; and (8) in the diminution backwards in the length of the marginal ‘spines, No trace of a pit on the line of the axial furrow, such as that which is so noticeable in D. lakei, has been detected in D. reticulata. The cranidia of the two species are very much alike, but the thorax and pygidia are decidedly different, and the reticulate character of the test, when it can be observed, is very distinctive. Microdiscus. Mricropiscus PuNcTArus Salter. J. W. Salter, Q. J. G. S. vol. xx (1864) p. 237 & pl. xiii, fig. 11. P. Lake, ‘ British Cambrian Trilobites’ Monogr. Pal. Soc. vol. Ix (1907) pt. 2, p- 36 (where full references are given) & pl. i, figs. 11-17. Of this form, only one specimen has been found [1471] in the Breccia-Bed. It consists of the concave interior of a cranidium, with some of the calcareous rock-matrix adherent in places. Those portions of the interior of the test which are clear of this matrix show distinctly a regular series of punctations, apparently deep enough to pass quite through the test. Mr. Philip Lake, who kindly examined the specimen, observes (in litt.) that ‘the crenulation of the margin does not look so fine and regular as is usual in M. punctatus. But possibly the nature of the matrix may have something to do with the difference in the appearance.’ 1Q. J. G. S. vol. Ixvii (1911) p. 287 & pl. xxv, figs. 1-8. 38 MR. E.S. COBBOLD ON THE TRILOBITE FAUNA [March 1913, Ptychoparia Corda. Subgenus Liostracus Angelin. PrycHoparta (Liosrracus) Lata, sp.nov. (PI. II, figs. 16 a-17 c.) Ptychoparia (Liostracus), sp. allied to Pt. (L.) pulehella Cobbold, Rep. Brit. Assoc. 1912 (Dundee). Of the seven or eight casts of cranidia in the collection from the Breccia-Bed the internal cast [1403] is selected as the type for the species. It is the only one that seems to retain the natural convexity without distortion. Cranipium: General form.—Trapezoidal, with front well rounded, so as to be a segment of a circle; features in strong relief. Size.—Length, exclusive of occipital spine, = 8 mm.; width across eye-lobe = 10 millimetres. General convexity.—UConsiderable ; ratio, about 1 : 3-2. Glabella.—Convex and wide ; tapering slightly forwards ; apex bluntly rounded; bent down strongly forwards; highest in the posterior third of the length ; widest at the base, where it is very little less than the length; two pairs of the lateral furrows are just discernible on the internal cast. Occipital furrow.—Wide and well-marked ; a little shallower in the middle than at the sides. Occipital ring.—Almost entirely merged in the base of a strong, but rather short, spine, which projects upwards to a height distinctly greater than that of the glabella, and backwards to a distance from the occipital furrow a little more than half the fength of the glabella. Axial furrow.—Continuous round the sides and apex of the glabella ; wide and well-marked, but not deep, except. when the head-shield has been compressed vertically. Fixed cheeks.—Scarcely half the width of the glabella; gently convex in the middle; descending steeply to the eye-lobe and towards the postero-lateral furrow, but more gently forwards; continuous by a narrow convex space round the apex of the glabella ; highest opposite the posterior third of the glabella. Eye-lobe.—Conyex and raised as compared with the slope of the cheek, from which it is separated by a distinct groove ; situated about half-way along the course of the facial suture, and having a length approximately equal to half that of the glabella. Postero-lateral border.—A rather flat: fold, widening a little outwards; separated from the fixed cheek by a wide and shallow furrow, with which the occipital furrow makes one straight line across the head-shield. Front.—Extending forwards for a distance nearly equal to half the length of the glabella, and consisting of three sub-equal parts : (1) a convex space, connecting the fixed cheeks; (2) a shallow hollow ; and (3) a convex marginal fold. - Vol. 69.] OF THE COMLEY BRECCIA-BED. 39 Facial suture.—Slightly convergent in front of the eye, more strongly divergent behind it. Test.—The external casts invariably show a granular surface ; but, as this varies in agreement with the coarseness or fineness of the matrix, it is probable that the external surface of the cranidium was smooth. This form has many points in common with Plychoparia (Lio- stracus) pulchella from the Davidis Fauna at Comley. It diflers, however, in the greater width of the glabella, the concurrent narrowness of the fixed cheeks, the absence of the ocular ridge, and in the shorter and more erect occipital spine. Also the eye- lobe appears to be somewhat larger and situated rather more forward. Through the above-mentioned species, Pt. (L.) lata is related to Pt. (L.) valida Matthew and Pt. (L.) linnarssoni Brogger. Prycgoranrta (L.) ? posta Cobbold. (Pl. ILI, figs. 19 a & 190.) Q. J. G.S. vol. Ixvii (1911) p. 295 & pl. xxv, figs. 19-21. Two small cranidia from the Breccia-Bed agree with this species, so far as they go. It is obviously quite possible, however, that they are immature individuals of the form Pz. (L.) lata. IV. The Stratigraphical Horizon of the Breccia-Bed. So many of the trilobites are either indifferently preserved, or belong to species hitherto undescribed, that any correlation of the Breccia-Bed with a well-defined Cambrian horizon elsewhere must be somewhat hypothetical. The two Welsh species, Conocoryphe bufo Hicks and Microdiscus punctatus Salter, are quoted from the Menevian of St. David’s, the former from the grey beds at the base of the group.’ M. punctatus is also found in Scandinavia, but was described by Linnarsson under the two names M. scanicus and M. eucentius.* Both at Andrarum* and at Bornholm®* it occurs in the P.-tessine Zone, and also, at the latter locality, in the P.-davidis Zone. Conocoryphe equalis Linnarsson marks a definite sub-zone near the top of the Scandinavian P.-tessint Beds, while C. impressa Linnarsson occurs in the lowest sub-zone of the same group. The two species are found at Andrarum (Moberg, op. cit.) and at Born- holm (Grénwall, op. cit. pp. 92, 101, & 168) in the same relative positions. 1 J. W. Salter & H. Hicks, Q. J. G. S. vol. xxv (1869) p. 53. be. Lake, ‘ Brit. Camb. Trilob.’ Monogr. Palzont. Soe. vol. xi (1907) pt. 2, a J.C. Moberg, Geol. Foren. Stockholm Forhandl. vol. xxxii (1910) pt. 1, pp. 57-59. ie ee A. Grénwall, Danmarks Geol. Underség. ser. 2, No. 13 (1902) pp. 79-81 we 10d. 40 MR. E. S. COBBOLD ON THE TRILOBITE FAUNA [ March 1913, Ptychoparia (Liostracus) lata appears to be closely related to Lnostracus linnarssont Brogger, which is found at Andrarum and Bornholm throughout the same Zessini Zone. The two forms Pt. (L.) dubia and Agraulos cf. quadrangularis are rather poorly preserved, but appear to be the same forms as those quoted from the Davidis Fauna of the Shoot-Rough-Road beds of Comley. A comparison of the fauna of the matrix of the Breccia-Bed with that of the Quarry-Ridge Grits shows a considerable contrast, the species of trilobites, so far as they are known, being all different. TABLE ILLUSTRATING THE CONTRAST BETWEEN THE TRILOBITES OF TIE Groomir FAUNA AND TIIOSE OF THE Breccri-Bep. | Species recognized up to the present. Genera. From the Quarry- ;From the Breccia- Ridge Grits. | Bed. Paradoxides .....0....0.06- groom Lapworth! ......... | intermedius, sp. nov. AGROB oc5s06c0000089000 INOME VOUINE! sonoedaccossenvese ef. A. quadrangularis (Whitfield). Agraulos (Strenuella)?...) None found ..................) Two species indeter- minate. Conocoryphe ......1...0000- emarginata Linnarsson, | | ah cr ee var. longifrons Cobbold § , SE aaa COMOGUPYWLG Soroncseocaccese| «—~—~=«s aoe 08000 _bufo Hicks. Comocand pe va cnceccewsn-il) ie ns yeeeeenes _ tnupressa Linnarsson. IDOPUFOUTO ranscocanacsonseo lakei Cobbold ............... reticulata, sp. nov. Microdiscus .......0.00000 | None found °..................| punctatus Salter. Ptychoparia (Liostracus}| None found ...............++- lata, sp. nov. Ptychoparia(Liostracus)?| None found ..............-+- | dubia Cobbold ? So far as they go, the species recognized indicate the presence at Comley of the Paradoaides-tessint Fauna, and it seems probable that the Breccia-Bed of Comley Brook represents part, if not the whole, of the P.-tessint Zone of Scandinavia. Fnrther, it seems clear that the Groom Fauna of the Quarry-Ridge Grits of Comley is quite distinct. V. Inferences. (1) Recalling to the reader’s recollection the fact stated above that the fossils found in the component blocks of the Breccia-Bed belong to the Helena group of the Protolenus-Callavia Fauna, while 1 Fragmentary remains indicate that there are two, or perhaps three, other species of Paradoxides which cannot at present be identified in the Quarry- Ridge Grits. Vol. 69. ] OF THE COMLEY BRECCIA-BED. 41 the matrix contains fossils of the Zessint Fauna, it would appear that, during the period represented by this latter fauna, a ridge of Lower Cambrian sandstones, from which the superincumbent Lower Cambrian limestones had been previously removed, was exposed to denudation, and that it was broken down, with little or no transportation of material, to form a sandy reef or shoal, which quite locally became a basal deposit of the Middle Cambrian. (2) 'The fact that the Groom Fauna of the Quarry-Ridge Grits (also a basal deposit) is quite distinct from the fauna of the Breccia- Bed, indicates that they are not contemporaneous, although both belong to Middle Cambrian time. We have, therefore, within the little district of Comley two basal deposits, separated in time by a sufficient interval to allow of a definite change of faunas. (3) The exact horizon of the Groomti Fauna in the general Cambrian succession cannot at present be stated definitely, but that it is older than the fauna of the Breccia-Bed appears probable from three considerations :—(1) The Conocoryphe which it contains is allied to C. emarginata Linnarsson, which is, so far as known, confined to the @landicus Zone of Scandinavia. qi) The fauna of the Breccia-Bed is more nearly related to the Davidis Fauna of the Shoot-Rough-Road Beds of Comley than the Groonit Fauna seems to be. (111) ‘The majority of the Lower Cambrian fossils found in the included blocks of the basal conglomerate of the Quarry-Ridge Grits belong to a somewhat higher horizon than those found in the component blocks of the Breccia-Bed ; it may therefore be inferred that more time was required for the denuding forces to reach the parent rock of the latter, and the probability is that the Breccia- Bed is the younger of the two basal deposits. VI. Conclusions. The lthological resemblance between the matrix of the Breccia- Bed, yielding Paradowides, and the beds of the Lower Cambrian sandstone, yielding Olenellus (sensu lato), is so close that, were it not for the presence of the fossils, it is doubtful whether I should have recognized its true nature. It was fortunate that this exposure was not discovered until after the local faunas of the Lower and Middle Cambrian had been fairly well established ; for it 1s easy to imagine how collections made from this spot near Comley Brook might have been held to prove that Paradowides and Olenellus were, in part at least, contemporaneous, in which case the Breccia- Bed would have been regarded as a passage-bed, where the two faunas overlapped. In view of the fact that a reticulate surface to the test of tri- lobites has hitherto, so far as known, only been found among Lower Cambrian forms, special attention may be called to that seen in Dorypyge reticulata, sp.nov. The resemblance to some parts of the tests of Callavia from Comley is very close. This reticulation is characteristic of the genera into which 42 MR. E. S. COBBOLD ON THE TRILOBITE FAUNA [ March 1913,. Olenellus (sensu lato) has been recently divided by Dr. Walcott.’ In only one species, Olenellus argentus Walcott, is it entirely replaced by another form of surface, a strongly granular one, and even this he regards* as but an extreme modification of original reticu- lation. ‘Two other species, Holmia rowei Walcott ® and Wanneria gracilis Walcott,’ have a granular surface on parts of the test, but this is accompanied by a set of fine raised lines. The same, or a very similar, reticulation is found in Bathynotus holopyge Hall, in Conocoryphe (Atops) reticulata Waleott, in a slightly modified form in Avalonia manuelensis Walcott, and in the Comley species Mohicana clavata Cobbold. If this character of test is a primitive feature, it seems inter- esting to find it in a Dorypyge of Middle Cambrian age. I cannot close this communication without expressing my in- debtedness to Prof. J. C. Moberg, who very kindly sent me copies. of the English translations of his Geological Guide to Andrarum, etc.” and of his ‘ Historical-Stratigraphical Review of the Silurian of Sweden,’ ® prepared on the occasion of the XIth International Geological Congress, 1910. They have been of great use, not only for the excellent bibliographies which they include, but also as giving a clear résumé of the work of previous authors. I am also indebted to Prof. K. A. Grénwall for gifts of publi- cations dealing with Swedish Cambrian horizons, and especially for his kindness in sending me a copy of his ‘ Bornholms Para- dowideslag* 1902. To Prof. Charles Lapworth I am again greatly indebted for continued help and encouragement. EXPLANATION OF PLATES II & III. Prate II. [All the figures are enlarged, except fig. 2, which is of the natural size. | Paradoxides intermedius, sp. nov. (See pp. 29-31.) . Internal cast of cranidium with left cheek flattened, and part of the external cast of the doublure visible on the right [1832]: @, view from above; 0, side view; c, view from behind, with the convexity of the left cheek restored ; all x 2. Fragmentary free cheek of a much larger individual with test partly preserved [1435]: referred with doubt to the species; natural size. . Internal cast of cranidium [1828]: the left front and side are bent down, and buried in the rock; X 2. Internal cast of fragmentary glabella [1440], referred with reserve to P. rugulosus Corda in Rep. Brit. Assoc. 1912 (Dundee). 5. Internal cast of fragmentary hypostoma [1449], with some portions: restored from the counterpart [1450]; x 2. 6. Internal cast of termination of pleura [1454]; x 2. — Fig. bo = SS) 1 C.D. Waleott, Smithsonian Mise. Coll. vol. liii, no. 6, 1910. 2 [bid. p. 515. 3 Thid. p. 294. + Ibid. p. 299. 5 Geol. Foren. Stockholm Foérhandl. vol. xxxii (1910) pt. 1, pp. 49-194. 6 Syer. Geol. Undersdkn. ser. C, No. 229 (1910). ' ‘és id Quart. Journ. Geor. Soc. Vor. LXIX, Put. ES.C, Del. Bemrose, Collo, Derby. a MIDDLE CAMBRIAN TRILOBITES FROM COMLEY (SHROPSHIRE). Quart. Journ. Geor. Soc. Vor. LXIX, Pt. Ill. Bemrose, Collo,, Derby. MIDDLE CAMBRIAN TRILOBITES FROM COMLEY (SHROPSHIRE). S.C. Del. et Photo, Sap Wana Vol. 69.] OF THE COMLEY BRECCIA-BED. 45 Fig. 7. 8. 9. 10. 11. it? 13. 14. 15. 16. Fig. 1. to Cs Drawn from plasticine mould of part of an anterior thoracie segment ; X 2; [specimen not preserved ]. Fragment of a posterior pleura [1455], with the probable position of the pygidium indicated by dotted lines; x 2. Internal cast of pygidium [1445]; x 2. Exterior of pygidium [1443]: @, view from above: /, side view : both « 2; c, surface of axial lobe; d, surface of margin: both x about 7. Internal cast of pygidium with a proportionately shorter axis, but probably belonging to the species [1817]: @, view from above, showing also the external cast of the wide doublure; 4, side view ; ce, view from behind; all x 2. Agraulos sp. indet. No. 1. (See p. 32.) Internal cast of cranidium [1878¢]. The occipital spine, which is restored in outline, was destroyed during deyelopment of the fossil ; it was in close agreement with that shown in fig. 13: @, view from above; b, side view ; c, view from behind; all x 3. Fragment of glabella and occipital spine [1398]; x 5. Agraulos sp. indet. No, 2. (See p. 32.) Internal cast of cranidium [1847]: @, view from above; %, side view ; ¢, view from behind; all x 3. The three pairs of glabellar furrows, the contour of the glabella in the side view, and the absence of all trace of ocular ridge, differentiate this form from that shown in fig. 12. Agraulos ef. quadrangularis (Whitfield). (See p. 51.) Internal cast of cranidium [1595]: a, view from above; /, side view ; c, section between the eye-lobes; all x 3. Ptychoparia (Liostracus) lata, sp. noy. (See pp. 38-39.) Internal cast of cranidium [1403], showing traces of two pairs of glabellar furrows: a, view from above ; 4, side view; ¢, view from behind; all x 2. . Internal cast of cranidium [1599] without glabellar furrows: a, view from above.; 0, side view ; ¢, section between the eye-lobes; all x 2. Puave IIT. [All the figures are enlarged. | Dorypyge reticulata, sp. noy. (See pp. 35-87.) Internal cast of cranidium [1407]: a, view from above, with free cheek restored in outline, x 2; 4, part of the exterior of the test from specimen [1411], fig. 5, x 10; c, part of the external cast of the test [1408], which is the counterpart of [1407], x 10. . Partial internal cast of cranidium, with the test preserved on the right side of the glabella, where the rugosities are interrupted in. two places marked X [1882]: @, view from above; 4, longitudinal section; X 2. The spine was destroyed during the development of the fossil,. and the cast of the nether side of the occipital ring was then exposed. . Internal cast of cranidium [1886]: a, view from above; 0, side view ;. ¢, view from behind ; all x 2. . Glabella of the smallest individual found [1415]; x 2. . Photograph of exterior of fixed cheek and eye-lobe (with the postero-- lateral margin pushed out of place by a vein of. calespar), showing,. with a magnifier, the surface-characters [1411]; x 2. . Internal cast of free cheek [1410], as seen lying in the rock; x 2. . External cast of the same free cheek [1414]; x 2. Lo, 16. pt “I 19. TRILOBITES OF THE COMLEY BRECOCIA-BED. March ror 913, . External cast of hypostoma [1814]; x 2. , Internal cast of another hypostoma [1585]: 7, convex view; 4, cross- section ; both x 2. In both these hypostomas the posterior margin is defective, and consequently the presence or absence of spines or hooks at the posterior angles cannot be determined. Anterior (?) pleura [1419] ; Ay = . Posterior (7) pleura [1419] ; Posterior (2) pleura and part ae axis [1817]; x 2. 3. Restoration of pygidium, chiefly from specimens [1819, 1819 @] which illustrate the size and almost all the characteristic features. One transverse groove has been accidentally omitted from the axial lobe in this figure. . Internal cast of part of pygidium [1434], which in point of size com- pares with the oxavnidenann, fig. 3: a, view from above; J, side view; both x 2. Minute pygidiam, with one thoracic segment [1472]; x 4d. Conocoryphe tipressa Linnarsson. (See p, 33.) Cranidium with test partly preserved [1884]: «, view from above; h, side view ; c, view from behind; all x 3. Conocoryphe bufo Hicks. (See p. 32.) . Internal cast of cranidium, with left cheek buckled by unequal pres- sure [1388]: a, view from above; 0, side view ; c, view from behind; all x 2. Conocoryphe equalis Linnarsson. (See p. 32.) Internal cast of cranidium [1393], with the missing parts restored in outline from the counterpart [1394]: @, view from above; 4, side view; ¢, view from behind; all x 3. Ptychoparia (Liostracus) ? dubia Cobbold. (See p. 39.) Internal cast of cranidium, with occipital ring damaged [1457]: a, view from above; 0, side view; both x 3, |For the Discussion, see p. 49. | Vol. 60. | PARADOXIDES YROM NEVES CASTLE. 45) 4. Two Spescrus of Parapoxmes from Nave’s Castie (SHRropsuirn). By Enear Srertine Cossonp, F.G.8. (Read December 4th, 1912.) [Puate LV. | A number of trilobites, collected for H.M. Geological Survey by Mr. T. Rhodes in 1892 from Neve’s Castle and Comley (Shrop- shire) have been submitted to me for study and identification by Prof. Charles Lapworth, under whose direction they were obtained. Among these are two species of Paradowides, from a dark flagey limestone at Neve’s Castle, that seem of special interest as. representing forms well known elsewhere, but not hitherto noted from Shropshire. The material available for description consists of a number of fragments of head-shields, several free cheeks and pleure, a few hypostomas and two pygidia. Almost every specimen has been subjected to a certain amount of distortion, and some have been crushed to a mosaic of small pieces, so that the natural convexity is lost. But the specimens are otherwise beautifully preserved: the tests, where unweathered, are intensely black, and show the delicate surface-characters excellently. PaRAvoXIDES BoHEMICUS Boeck, var. satoprEnsis, nov. (Pl. IV,. figs. 6-17.) J. de Barrande, ‘Syst. Silur. Bohéme’ vol. i (1852) p. 867 & pl. x. The fragments on which this variety is founded, taken together, indicate a close agreement with Barrande’s description and figures, and with some Bohemian specimens which, through the kindness of the Keeper of the Geological Department of the British Museum (Natural History), [ have had the opportunity of studying. ‘There are, however, the following divergences, which are constant :— (1) The eye-lobe is proportionately longer. (2) The posterior branch of the facial suture is concurrently shorter, and its general course is less steeply inclined to the posterior border. (8) The free cheek is proportionately shorter and wider, and has a slight intra-marginal ridge. (4) The points of the pleura are more slender. (5) The pygidium is more quadrate in outline, and has only two. annulations on the axis apart from the articulating facet. The cranidia figured (Pl. LV, figs. 6, 8, 9, & 12) are from 13 to 26 mm. long, and the eye-lobes are about half these lengths. In Bohemian specimens the proportion is more nearly a third. The front of the glabella is always truncately rounded, and has about twelve lines of discontinuous hair-like rugosities (figs. 10 & 11). near the anterior border. Similar rugosities are seen on some of the 46 MR. E, 8. COBBOLD ON TWO SPECIES OF [March 1913, Bohemian specimens, but are not mentioned in the description. Rather stronger rugosities are seen on the anterior border itself, and these creep over the margin on to the doublure in their course towards the facial suture. The area of the free cheek (PI. LV, fig. 7) is flat and wide, its jateral border is gently but decidedly convex, and paraliel with it there is a slight rise in the surface forming the incipient intra- marginal ridge, which J have not seen indicated in any of the figures of the Bohemian specimens. The pleure (Pl. LV, figs. 13 & 14) have a rather narrow groove, terminating subcentrally in the anterior portion of the thorax (fig. 13) and close to the posterior margin in the more posterior segments (fig. 14). The point, which is directed strongly backwards, is connected with the body of the pleura by a bold curve, and is decidedly slender. In Barrande’s figures (op. cit. pl. x) the points are much wider. The pygidia figured here (Pl. LV, figs. 15 & 16) are rather small; but, on comparison with Barrande’s figure of the complete trilobite, are not smaller than might be expected to accompany the smaller cranidia (figs. 8 & 9). They both show a more quadrate outline than the Bohemian specimens, and have only two transverse furrows on the axis instead of three. Fig. 16 shows an approach to an oval form, but has fairly straight sides. The hypostoma (PI. IV, fig. 17) seems to be quite the same as the Bohemian form. Test.—Apart from the rugosities already mentioned, the surface ‘is smooth. Comparison with the Allied Species. In P. tessint Brongniart the front of the glabella is pointed, the glabellar furrows, though curved, are more direct; the length of the eye-lobe is less than a third of that of the head-shield; the posterior branch of the facial suture is relatively longer and inclined at a more acute angle to the margin; the pygidium is distinctly spatulate, being wider behind than in front, and it has three or four furrows across the axial lobe; the curve joining the body of the pleura to its point is of comparatively short radius. The Shrop- shire form approaches P. tessii in having*the points of the pleura slender. In P. harlant Green the front of the glabella is well rounded ; the glabellar furrows are nearly direct; the length of the eye-lobe is less than a third of that of the head-shield; the facial suture behind the eye is relatively longer, and inclined more acutely to the margin; the pygidium is almost circular, and has but one furrow across tne axial lobe; the pleural points are comparatively wide ; and there is a tubercle cn the occipital ring. The cranidium of P. abenacus Matthew has a general form very similar to that of the Shropshire variety ; the eye-lobe is as large -or larger; the glabella is truncately rounded in front, and traversed Vol. 69. | P1RADOXIDES ¥ROM NEVW’S CASTLE. 47 ‘by two well-marked continuous furrows posteriorly, but has in addition two pairs of faint lateral furrows on the anterior portion ; and there is a tubercle on the goatee ring. Locality and horizon.—Neve’ s Castle (Shropshire), near the southern end of the Wrekin. Middle Cambrian. Parapoxipes wicks Salter. (PI. IV, figs. 1-5.) 1865. J. W. Salter, Rep. Brit. Assoc. (Birmingham) p. 285. 1868. J. We So & H. Hicks, Q. J. G.S. vol. xxv (1869) p. 55 & pl. iii, 1883. Gin tee tcais Sver. Geol. Undersékn, ser. C, No. 54, p. 14 & pl. iii, figs. 1-5. Five of the cranidia from Neve’s Castle, with two free cheeks and a few other fragments, seem to indicate the presence of Salter’s species in Shropshire ; but the state of preservation of the specimens is very different from that of the specimens obtained at St. David’s. Four of the cranidia, with lengths varying from 15 to 25 mm., have the characters of adult individuals, but do not exhibit the very pronounced enlargement of the glabella bey on ae anterior margin ‘that is shown in Salter’s figures (op. cit. pl. ii, figs. 1 & 2). The fifth cranidium (Pl. LV, fig. 4)is 12 mm. long, ao shows characters attributed to immature forms. The glabella is strongly convex, widest at about two-fifths of its length from the front, and has the anterior of the four pairs of furrows just behind this point, not in advance of it, as shown by Salter. In the immature form, however, this furrow lies farther forward, and in agreement with the figures of the St. Dayid’s ‘specimens. The posterior furrows cross the axial line, but the others are interrupted towards the middle; all, except the anterior pair, are connected with the axial furrow. The occipital furrow is bent a little forwards in the middle; and the occipital ring is decidedly broader than the posterior glabellar lobes. The fixed cheek is but slightly convex, and the eye-lobe is separated from it by a strongly marked parallel hollow. In the largest specimen (fig. 2a) the length of the eye-lobe is a third of that of the cranidium ; in the amnesia sized specimens (fig. 3) the length of the eye-lobe is rather greater; and in the immature form (fig. 4) it is more nearly a half. The anterior border is narrow, nearly straight on either side, and somewhat obscured in front by ithe overhanging glabella; but in the smallest head-shield the fold stands clear of the glabella by a distance equal to about half its width. The characters of the test are very well shown on specimen No, 2376, from which fiz. 2 was drawn. ‘The glabella is quite smooth on the frontal lobe, but granular on the centrai and pos- terior portions. On the cheeks (tig. 2) the granulations become ‘coarser, but are not so much elongated as is indicated in Salter’s figures (op. cit. figs. 1 & 2); on the occipital ring they are, however, elongated, and arranged more or less concentrically round a node -or low tubercle in tiie middle of the ring (PI. IV, fig. 2¢). 43 MR. E. S. COBBOLD ON TWO SPECIES OF [March 1913, The two free cheeks which may be referred with little hesi- tation to the species (figs. 1 & 5) belong to larger individuals. The area 1s decidedly wide, particularly near the posterior margin, but in both specimens it is crushed to a mosaic, and its original form cannot be accurately determined; the marginal fold is fairly convex, and is continued to form a long and sharp spine, the length of which is about equal to that of the cheek itself. The upper surface of the fold shows a few raised lines, which creep over the margin on to the doublure, where they become more plentiful. In Salter’s. description the margin is said to be smooth. On specimen No. 2422 (Pl. LV, fig. 1) a few similar lines are to be seen on the under side to the area of the cheek, where they run in a direction sub-parallel of the curve of the eye. Locality and horizon.—Neve’s Castle (Shropshire), near the southern end of the Wrekin. Middle Cambrian. Conclusions. The rock-specimens, in which the two species of Paradoxides are found, contain a few other fossils, among which the following have been recognized :— Agnostus sp., ef. A. fallax Linnarsson. | Agraulos sp., ef. A. quadrangularis Agnostus sp., of the type of A. cicer (Whitfield). Tullberg. Hypolithus sp. Ptychoparia (Liostracus) sp., compare | Hyolithellus sp., ef. H. fistula Hall. ‘the forms from Coimley. | Acrotreta sp. Until further specimens of the smaller trilobites are forthcoming, it is impossible to say definitely which horizon of the Middle Cambrian is represented. Paradoxides hicksi, the two above-named species of Agnostus, and a similar form of Liostracus are found in the Yessini Zone of Scandinavia. For preyiously-published references to the Neve’s Castle locality see :— 1877. C. Callaway, Q. J. GS. vol. xxxiii, p. 662. 1894. C. Lapworth & W. W. Watts, Proc. Geol. Assoc. vol. xiii, p. 310. 1910. C. Lapworth & W. W. Watts, Geol. Assoc. Jubilee vol. pt. 4, p. 790. 1911. E. S. Cobbold, Q. J. G. 8. vol. Ixvii, p. 285. EXPLANATION OF PLATE IV. [All figures are of the natural size, except 2c & 2d. The letters and numbers in square brackets are those attached to the specimens. | Paradoxides hicksi Salter. (See p. 47.) Fig. 1. Free cheek [R.R. 2422]. ; . Nearly complete cranidium, somewhat flattened [R.R. 25876]: a, seen from above; 6, seen from the side; ¢, enlargement of the median part of the occipital ring; d, enlargement of part of a fixed cheek. . Incomplete cranidium, somewhat flattened [R.R. 2394]. . Nearly complete cranidium of immature individual [R.R. 2380]. . Free cheek of a comparatively large individual, much crushed [R.R. 2422]. bo Our co Quart. Journ. Geot. Soc. Vor. LXIX, PL.IV. ES: G, Del. Bemrose, Collo., Derby. PARADOXIDES FROM NEVES CASTLE (SHROPSHIRE). Vol. 69. ] PARADOXIDES FROM NEVE’S CASTLE. 49 Paradowxides bohemicus Boeck, var. salopiensis, noy. (See p. 45.) Fig. 6. Cranidium, somewhat flattened [R.R. 2385]. 7. Free cheek, referred with reserve to this species and yariety [R.R. 2435] 8. Cranidium, somewhat flattened and crushed [R.R. 2485]. 9. Fragmentary cranidium, less flattened [2415]. 10. Dome of glabella, showing rugosities [R.R. 2429]. 11. Dome of glabella and part of margin, showing rugosities [R.R. 2388]. 12. Part of cranidium of larger individual, showing the posterior braach of the facial suture [R.R. 2416]. 13. Part of one of the anterior (?) pleurse [R.R, 2425]. 14. Coinplete pleura, from the posterior (?) part of the thorax [ R.R. 2587 Figs. 15 & 16. Pygidia, seen from above and from the side [R.R. 2382 & 242 Fig. 16. Hypostoma and doublure [R.R. 2427]. 0 |. |. DIscUssioN ON THE TWO FOREGOING PAPERs, Mr. W.G. Frarnsripes congratulated the Author on his palzonto- logical discoveries, and on the close parallelism which he had been able to prove between the Middle Cambrian rocks of Shropshire and the Paradowides-tessint Zone ot Sweden. As bearing upon the mode of accumulation of the fossiliferous breccias described, he drew attention to the following points :— (1) The fossiliferous matrix of the breccia contains glauconite, (2) The enclosed fragments of the Lower Cambrian rocks are quite unweathered; they too are glauconite-bearing, while the fossils which they contain are preserved unaltered and consist largely of calcite, (3) All the included fragments are markedly angular, and many of them have bounding-surfaces which meet at acute angles, On this evidence the speaker would conclude that the erosion which broke up the Lower Cambrian sandstone into fragments took place in situ, and was not a subaérial but a submarine process. He suggested that the Lower and Middle Cambrian rocks of Shropshire, like the contemporaneous rocks of Northern Ciland, are the record of a condition when sedimentation and submarine erosion were nicely balanced ; when only the larger fragments, and the interstitial sand sheltered between them, remained unmoved by the currents, and were preserved as sedimentary rock. The occurrence of phosphatic nodules in beds interstratified with glauconitic sandstones also pointed to the same conclusion. Mr. G. W. Lamptuen remarked that marine sedimentation was often a discontinuous process, and that gaps in a stratigraphical sequence, even when accompanied by erosion, did not necessarily imply elevation above sa level, Among the Mesozoic rocks it was not unusual to find glauconitic and phosphatic deposits of little thickness, which evidently represented long periods of arrested sedimentation, and sometimes of submarine erosion. It was also know that the floors of cur present seas were being scoured and eroded in many places. OFd.G.s. No, 272. E 50 MIDDLE CAMBRIAN TRILOBITES. [March 1913, Prof. W. W. Warrs pointed out that phenomena of brecciation like those described by the Author were being recognized as of frequent occurrence, especially in limestones. They were especially well known in cornstones and in limestones of tufaceous character, but they were also found in such well-bedded marine limestones as those of the Carboniferous System. Hitherto, no general explanation of the phenomena had been given. Mr. E. Grerniy, while admitting the possibility of con- temporaneous erosion, thought that an unconformity was to be expected at the horizon mentioned. Despite the thickness of the Cambrian deposits of Carnaryonshire, the zone of Olenellus had not yet been detected. Cleavage, it was true, was strong; but the evidence now brought forward by the Author tended to confirm the suspicion that the Olenellus Zone might have been overlapped, or even removed, by erosion along the slope of the old land, ata very early period. The AvurHor, in reply, said that there were phosphatic beds among the Cambrian rocks of Comley which might mark pauses in the sedimentation, but these were distinct from the breccias or conglomerates. The breccias and conglomerates he regarded as representing detritus from cliffs or islets, rather than as the result of what was formerly called ‘ contemporaneous erosion. The older fossils found in them were furnished by the angular blocks, and belonged to the Protolenus-Callavia Fauna, which, on the analogy of American sections, occurred well down in the Lower Cambrian ; Dr. Walcott had shown that the telson-bearing Olenelli, which had not as yet been found in Shropshire, marked a higher horizon than that of the Protolenus Fauna. The paleontological break between the Lower and the Middle Cambrian of Comley, as described by the Author in a previous communication to the Society, was very great, and was matched by the physical unconformity which the excavations had proved to exist in the district. This unconformity appeared to be just what was required for the elucidation of the hiatus mentioned by Mr. Greenly. In conclusion, the Author thanked the Fellows for their kindly reception of his papers. Vol. 69. } THE GENUS AULOPHYLLUM. dL 5. On the Genus AuLorayritum. By Srancey Suirn, B.A., M.Sc., F.G.8., Clare College, Cambridge. (Read November 20th, 1912.) [Puarns V-IX.] ConTENTS. Page eM PROGUICEON Sere tener n se U eh tee cncor coe acer ene dl TPRBTG teat ume ress esc a serracasiciciersaG rosette ciclgc ee ra Se ceReeiecee 52 iE Sources of Material Studied <.........-..-...-------0.--0- 56 IV. General Description of the Genus ..................... 58 WW Onto menionis itis: teste sesh an aed a tasecavent i checchea cece: 60 Wil, Siremneivorall \WEyPRUPOMS Josdsonbobocods scodseboaceaconeceooeone 66 VII. Classification and Consideration of Time-Variants... 69 VIII. Local Characteristics and Variations .................. 70 XEN Stereo plasmic yRhiekenitlow cress -rereee scenes seeeae tees 72 PNEPBIUG|MIVEHESCONCE:* sts) voracnuasempenel eee saancussen seat ce 02 I. Iyrropucrion. AULOPHYLLUM occurs in the higher horizons (the Dibunophyllumn Zone) of the Lower Carboniferous of Great Britain, and is particu- larly abundant in Scotland and the North of England. Mr. J. A. Douglas has recorded ‘ Cyclophyllum sp. from the Carboniferous Limestone (D) of County Clare (Ireland),* and Dr. A. Vaughan * Cyclophylla’ from the equivalent horizon at Visé (Belgium) ? ; while Kunth reported its occurrence at Hausdorf, near Glatz, on the south-western border of Silesia.* Mr. R. G. Carruthers has described a specimen from Novaya Zemlya,* which proved its existence at as high a latitude as 70° 49’ N. Dr. G. H. Girty, on the other hand, believes that the genus has not been recorded from the United States.’ The corals studied were partly collected by myself, but for a large portion of the material I am indebted to the generosity of Mr. John Bishop, Mr. R. G. Carruthers, Mr. John Dunn, Prof. E.J. Garwood, Dr. W. T. Gordon, Mr. Leonard Gill, Mr. Thomas Herdman, Dr. Wheelton Hind, Mr. W. B. R. King, Dr. F. L. Kitchin, Mr. A. ©. Sandys, Dr. T. F. Sibly, Mr. C. T. Trechmann, Dr. Arthur Vaughan, Mr. F. H. Walker, Mr. Geoffrey Weyman, and Dr. Albert Wilmore. The preparation of material, its examination, and the literary 1 «The Carboniferous Limestone of County Clare (Ireland)’ Q. J.G.S. vol. Ixv (1909) p. 550. 2 ¢Faunal Succession in the Lower Carboniferous (Avonian) of the British Isles’ Rep. Brit. Assoc. 1910 (Sheffield) table facing p. 108. 3 See Bibliography, § II [11]. + Ibid. {14}. ° Private communication. 52 MR, STANLEY SMITH ON [March 1913, research have been carried out at the Sedgwick Museum, Cambridge ; and I take this opportunity of expressing my thanks to Prof. T. McKenny Hughes, F.R.S., for these privileges and for the kindly interest that he has shown in my work. My thanks are also cordially tendered to all those who have aided me with suggestions and criticism, especially to Mr. R. G. Car- ruthers, Mr. W. D. Lang, Mr. Henry Woods, and Dr. Arthur Vaughan. Lastly, | thank Mr. Frederick Phillips for his assistance in the preparation of sections. Il. Lireratvre. (1) Synonymy. Only the more important works bearing upon the coral are here enumerated. (W793) Rungites. eee) UR DS he Mostory, of Ruthercler & East Kulbride’ pp. 327-28 & pl. xx, fig. 6. (2] 1828. Turbinolia fungites ........ Furmine, J. ‘A History of British é Animals’ p. 510. [3] 1830. Lurbinolia fungites .......... Woopwarp, 8. ‘A Synoptical Table of British Organic Remains’ p. 7. [4] 1834. Durbinolia fungites ......... De Buarnvittz, H.M.D.pr. ‘ Manuel F d’Actinologie ou de Zoophytologie’ p. 342. [5] 1846. Cyathophyllum fungites ... Gurtyitz, H. B. *Grundriss der Ver- steinerungskunde’ p. 571. [6] 1849. Clisiophyllum prolapsum ... M‘Coy, F. ‘On some New Genera & Species of Palzeozoic Corals & Forami- nifera’ Ann. Mag. Nat. Hist. ser. 2, vol. iii, p. 3. [7] 1850-54, Aulophyllam ................ Minne HEpwarps, A., & Hare, J. ‘A Monograph of the British Fossil Corals’ pp. Ixx & 188-89, pl. xxxvii, fig. 3, pl. xxxviul. fig. 1 (Pal. Soc.). [8] 1851. Aulophyllum ..................__ Idd. ‘Monographie des Polypiers Fos- siles des Terrains Paléozoiques ” pp. 413-14. [9] 1854. Clisiophyllam prolapsum ... M‘Coy, F. ‘ A Systematic Description ° of the British Palgeozoic Fossils in the Geological Museum of the Uni- versity of Cambridge’ pp. 95-96 & ~ wan pl. 1 ¢, figs. 5-5 a. [10] 1867. ee net wee. DUNCAN, PMS Lnomwsons Jb Om UCT TIGL) Cyclophyllum, a New Genus of the Cyathophyllide, with Remarks on the Genus Aulophyllum’ Q. J. G. S. vol. xxiii, pp. 327-30 & pl. xii. [11] 1869. Awlophyllum .................. unto, A. ‘Beitrage zur Kenntniss fossiler Korallen’ Zeitschr. Deutsch. Geol. Gesellsch. vol. xxi, pp. 201-205 & pl. iu, figs. 2a-2b. Tuomson, J. ‘Ona New Family of Rugose Corals, including the Genera Cyclophyllum, Aulophyllum, & on the Genus Clisiophyllum’ Proc. Glasgow Phil. Soe. vol. xiii, pp. 471-516 & pls. 1-1v. 112] 1882. Cyclophyllum. ) Aulophylluin., § Vol. 69. ] THE GENUS 4ULOPHYLLUM. 53 [13]21906. Cyclophyllum ................ Vauewan, A. ‘The Carboniferous Limestone Series (Avonian) of the Avon Gorge’ Proc. Bristol Nat. Soc. ser. 4, vol. i, p. 146. [14] 1909. Awlophyllum .................. CaRRuTHERS, R.G. ‘A Carboniterous Fauna from Novaya Zemlya collected by Dr. W.S. Bruce, by G. W. Lee; with Notes on the Corals by R. G. Carruthers’ Trans. Roy. Soc. Edin. vol. xlvii, p. 149. Non 1808. Fungites ......... cscs. Parxkrnson, J. ‘Organic Remains of a Former World’ vol. 1i,]. 120. 1836. Turbinolia fungites ......... Purnrtrps, J. ‘Illustrations of the Geology of Yorkshire’ pt. 2, p. 203 & pl. ui, fig. 23. 1842-44. Cyathophyllum fungites. Wontnex, L. G. pr. ‘Description des Animaux Fossiles qui se trouvent dans le Terrain Carbonifére de Bel- gique’ p. 24.& pl. D, fig. 2. 1843. Cyathophyllum fungites...... PortiocK, J. EK. “ Report on the Geology of Londonderry, & of parts of Tyrone & Fermanagh’ p. 328. (2) Summary of the Work of Previous Authors. The genotype of Auwlophyllum was figured and described by David Ure in 1793 as Fungites |1]." The name Fungites was originally given by Martini to a Halysites-like form, Mwigites catenulatus, in 1765. 2 In 1828 Fleming assigned Ure’s form to the genus Twi _binolia [2] of Lamarck’ (an aporose form), and used ‘ Fungites’ : in the specific sense ; hence to him must be credited the authorship of the species fungites. Geinitz, in 1846, transferred the species to the genus Cyathophylluin [5] of Goldfuss.* M‘Coy, in 1849, de- scribed some specimens of the coral in the Woodwardian Museum, Cambridge, and referred them to Dana’s’ genus Clisiophyllum, naming them Clisiophyllum prolapsum [6]. Milne Edwards & Haime took M‘Coy’s species as the genotype of their new genus Aulophyllum [7] in 1850, and described it as follows, [7] p. lxx:— ‘Corallum simple. Septa well developed. A double mural investment; the interior wall dividing the visceral chamber into two portions—one central and columnar, the other exterior and annular. No columella. Tabule but little developed,’ M‘Coy objected to the establishment of the new genus in his next publication (1854) [9] on the grounds that its characters were * Numerals in square brackets refer to the papers enumerated in the fore- going bibliography. “2 BH W. Martini, Berl. Mag. vol. i, p. 268 & pl. i, fig. 4. a B. P. A. de M. Lamarck, enstaime Naturelle des Animaux sans Vertébres’ vol. ii (1816) p. 230. * A. Goldfuss, ‘ Petrefacta Germaniz’ (1826) p. 54. ° J. D. Dana, ‘Zoophytes: U.S. Exploring Expedition’ vol. vii (1846) pp. 361-62 & pl. xxvi, figs, 6-7. ot MR. STANLEY SMITH ON (March 1913, insufficient to justify this generic separation. He stated, [9] pp. 95 & 96, that ‘This species forms the type of the genus Awlophyllwin of MM. Milne- Edwards and Haime, from the definite tubular boundary to the inner area or axis ; this, however, is merely a question of degree, serving to distinguish a well-marked species, but scarcely applicable as grounds of generic division ; for this inner area or axis is more or less defined in all [ Clisiophylla|, and different parts or ages of the same specimen show variation in this respect.’ In his figure, however, M‘Coy represents the ‘boundary to the inner area’ as being much thicker and more solid than it really is ; while he shows the tissue within this wall as thin and crowded, dome-like tabule, and does not emphasize its true composite nature. In criticizing the statements and conclusions of the earlier authors, it must not be forgotten that their researches were made without the aid of thin sections. M‘Coy’s observation that the wall is a character common to all members of his accepted genus Clisiophyllum is correct, in so far as the term merely defines the limit of the central column. His objection to the generic separation of the species prolapsum, merely upon the more pronounced nature of the boundary of the inner area, is scientifically sound and reasonable. Were the division of Aulo- phyllum from Clisiophyllum solely dependent upon that feature, his views regarding the generic identity of the two would be mnassailable. In addition to the accentuated boundary, the central portion of Chistophyllum prolapsum exhibits other and more important dif- ferences which distinguish it from the other species of the genus described by M‘Coy. It has no columella or mesial plate, and the central tissue consists of small, irregular tabulee, concave towards the calyx, surrounded by plates bent sharply towards the proximal end of the corallum; while in Clisiophyllum proper, simpler tabule slope at a more gentle angle from the trabeculate columella. he vertical lamelle of the central column are far more numerous in Aulophyllum than in Clisiophyllum and its allies. Although the distinctive features of Aulophyllum separate it from the latter, yet the possession of a distinct central column con- taining lamelle, groups these into a well-marked sub-group of the Cyathophyllidee—the Clisiophyllidze. Milne Edwards & Haime replied to M‘Coy’s criticism in a later part of their monograph, maintaining that their reasons for generic separation were valid. They described two species, dulophyllum fungites and A. bowerbanki,' the specific differences between these being that the former had more numerous septa, and an inner wall wider in proportion to the diameter of the corallum than the latter. Duncan & Thomson, in 1867 [10], expressed the opinion that A. fungites and A. bowerbanki could not remain in the genus Aulophyllum as defined by the French authors, maintaining that 1 A, bowerbanki is described in Milne Edwards's & Haime’s monograph as having been found in Ireland. ‘The type-specimen preserved in the British Museum is labelled ‘ Oswestry.’ Vol. 69.] THE GENUS AULOPHYLLUM. 5) these forms did possess a columella. On this ground they created a new genus, Cyclophyllum, and restricted Aulophyllum to forms in which the middle portion of the central column is occupied by tabulz only, and not invaded by the septal lamelle. Their description of Cyclophyllum was as follows (op. cit. p. 328) :— ‘The corallum is simple, tall, cornute, or more or less cylindrical. ‘The wall is very thin, and is formed of epithecee. The calice is deep, and its margin sharp ; there is a central projection at the bottom of the fossa, separated from the ends of the larger septa by a deep groove. This central mass consists of an endothecal covering, with numerous septa attached to it internally, and coalescing to form some large septa, which ramify over the central depression which represents the top of the columella. ‘The columella is essential, and is made up of laminz which arise from the base of the corallum, and trom the dissepiments which unite them, The endo- theca is largely developed, and the septa are very numerous. There isa fossula with three small septa in it, and a process of the endotheca of the central mass projects into it.’ The separation appears, at first sight, a very reasonable and desirable one. Closer investigation, however, discloses serious objections. The authors state that a columella is essential; but, after a careful study of Thomson's figures published in his’second paper and also of many actual specimens, [ am convinced that no columella occurs, not even a pseudo-columella. It is true that the lamella within the ‘central mass’ (defined by Thomson [12] as ‘septa’) do coalesce ‘ to form some large septa, which ramify over the central depression,’ the result being a network of tissue weakening towards the centre. In most specimens some of the lamelle reach the centre of this inner area; but in a few cases they all fail to do so, and the Aulophylloid character is produced. This may happen at different parts of the same individual. I am, therefore, compelled to reject the genus Cyclophyllum, and to refer all forms of Thomson’s ‘Diplocyathophyllide’ to Aulophyllum. Kunth included a description of the genus as Aulophyllum fungites in his paper on fossil corals (1869) [11], and identified with it Ludwig’s species Cyathodactylia undosa and OC. stellata’; but neither the definition nor the figures of these are convincing. The latter, in fact, bear little resemblance to Aulophyllum. In 1882 Thomson published a second paper [12] dealing with Cyclophyllum and Aulophyllum at some length. He embodied in it the conclusions drawn from the examination of over eight hundred sections of Cyclophyllum and twenty sections of Aulophyllum trom the Carboniferous Limestone of Scotland. He acknowledged the close relationship existing between his two genera by placing them in anew family, which he called Diplocyathophyllide. He, further, cut the original specimen of Ure’s Fungites preserved in the collec- tion of the Royal Society of Edinburgh, giving illustrations of the sections (op. cit. pl. ii, figs. 1, 1a, & 1 6), and described it as Cyclo- phyllum fungites, maintaining that it had ‘no generic relationship 1 R. Ludwig, ‘ Corallen aus Paliolithischen Formationen’ Palzontographica, vol. xiv (1865-66) pp. 160-61 & pl. xxxvi, figs. 1-2. o6 MR. STANLEY SMITH ON [March 1913, to the genus Aulophyllum’ (pp. 480-81), his reasons being the presence of what he considered the columella. The following species were described by him :— CYCLOPHYLLUM : C. fungites, C. urcanuin, C. bowerbanki. C. biacuminatum, C. pachy- endothecum, C. obovatum, C. scoulerianum, C. duncanianum, C. ellipticum, C. orhiculum, C. carpenterianum, C. bennicanum, C. m‘kendrickianum, C. curvilineare,* C. concentricum, C. cylindricum, C. frondicum,* C. tor- tuosum, C. paradoxacum,* C.intermedium, C. radianum,* C. moseleyanum, C. vesicularuin. AULOPHYLLUM : A. patrichianum,* A. fungites, A. edwardsianum, Vol. 69 US AULOPHYLL bi The minor constrictions of the corallum, shown in text-fig. 1 (p. 58), which are so marked a feature in most Rugose corals, are very similar to those resulting from rejuvenescence ; but they are much less pronounced. They do not appear, however, to be accompanied by any changes in the internal structure of the coral, except in the width of the dissepimental zone: unless the irregu- larities observed (p. 59) in the width of the central column bear some relationship to them, but this connexion is not at all obvious. Nevertheless, the contractions of the dissepimental zone probably originated from the same zone as rejuvenescence—possibly con- traction on the part of the polyp itself. It may be suggested that, if the contraction of the polyp was carried beyond a certain point, it resulted in the structural changes in the corallum just described. Such extreme cases, it would seem, are comparatively rare. This suggestion is not necessarily antagonistic to Bernard’s theory. The reduction in the width of the corallum, the central column, and the dissepimental zones, and in the number of the septal lamella, also the straightening-out of the pericentral vesicles, recapitulate the characters of the younger stages of growth. EXPLANATION OF PLATES V-IX. [The sections are now preserved in the British Museum (Natural History), South Kensington. | Puate V. Aulophylium fungites (Flem.), Sections illustrating ontogenesis and phylogenesis. All! from Peterhill Quarry, Bathgate. Wig. 1. Transverse section at the conclusion of Stage A. The six primary septa have been inserted ; and the first two of the secondary septa are appearing at the alar fossule A and A’, and marking the commencement of the Zaphrentoid Stage. (C=cardinal septum; A and A'=alar fossule; K=counter-septum.) x 4. 2, ‘Transverse section at the conclusion of Stage B. The separation of the septa at the centre and the presence of a rudimentary central column indicate the passage into Stage C. x 4. 3. Transverse section, Stage C, early phase. Septa penetrating the central column. Large cardinal fossula. x 4. 4, ‘Transverse section, Stage C, later phase. Most of the septa are free from the central column, and the cardinal fossula is not so prominent as in fig. 3. x 4. 5a. Transverse section, Stage D. The central column has the character of mut. redesdalense. X 1:5. b. Transverse section, Stage EH. x 1:5. ce, Transverse section, Stage F, showing the characters of mut. pachy- endothecum. X 1d. 6. Transverse section, mut. redesdalensc. Fourlaws Limestone, Water- falls Quarry, near Redesdale (Northumberland). x 1:5. 7 0. Transverse section, ‘tortuous’ type. Mut. pachyendothecwin. 7a. Harlier transverse section of the same individual at Stage E, showing the subquadrate aspect of the central column. Figs. 8 & 9. Transverse sections, mut. pachyendothecum, showing different rates of growth. Fig. 8 is cut at 5 ems. and Fig. 9 at 8 cms. from the proximal end of the coral. Both figuresare of the natural size. 5 5 76 MR. STANLEY SMITH ON [March 1913, Pruatze VI. Aulophyllum fungites (Flem.). Sections illustrating the variability _ of the species. All from Peterhill Quarry, Bathgate. [The magnifi- cation in every case is 1°5.] Fig. 1. Transverse section, ‘ radial’ type. Mut. towards pachyendothecum. 2. ‘Transverse section, ‘radial’ type. Mut. pachyendothecum. 3. ‘Transverse section, ‘rose’ type. Mut. towards pachyendothecum. 4a. Transverse section, ‘rose’ type. Mut. pachyendothecum. 4. Vertical section of the last-figured specimen. ‘The section passes through the middle of the central column in the upper part of the coral, but approaches the margin of the same in the lower part. Contrast this figure with Pl. VEI, fig. 30. Puate VII. Aulophyllum fungites (Flem.). Forms from Northumberland and Durham. [The magnification in every case is 1°5.| Fig. 1. Transverse section. Mut. towards pachyendothecum, but little advanced upon Stage E. Central column of the ‘radial’ type. Thornbrough Limestone, Thornbrough Quarry, near Corbridge (Northumberland). 2. ‘Transverse section. Mut. towards pachycndothecum. Small variety from the Thornbrough Limestone, Stanton (Northumberland). Apparently a dwarfed form of fig. 1. 3a, Transverse section of a smaller example of fig. 4. Columella of the ‘rose’ type. 3 0. Vertical section of fig. 3a. Note the numerous and compacted vesicles in the central column and the small regular outer dissepiments. 4, ‘Transverse section. Mut. pachyendothecum. A variety especially characteristic of the Great Limestone, Weardale (County Durham). Also common in other beds in the Weardale and Alston district. Note the small but densely-packed central column. From the Great Limestone, Stanhope-in-Weardale.. 5. ‘Transverse section. Mut. towards pachyendothecum, showing a ‘rose’ type, and a very wide space between the ends of the septa and the central column. Great Limestone, Black Pasture Quarry, near Chollerford (Northumberland). Prare VIII. Aulophyllum fungites (Flem.). Forms from Cumberland and Wales. The magnification in every case is 1°5.| gs. | & 2. Transverse sections. Mut. cumbricnse, Humphrey Head (More- cambe Bay). 3. ‘Transverse section. Mut. tenbiense, Lydstep (Tenby). 4. ‘Transverse section of another specimen from Humphrey Head, cut through Stage D, showing the characters of mut. tenbiense. 5. Transverse section. Mut. towards pachyendothecum, not much advanced upon Stage D; variety from Gleaston, near Barrow-in- Furness. 6a. Transverse section of the last at Stage D, showing characters similar to those of mut. tenbiense. 6}. Transverse section. Mut. near pachyendothecum. Craignant, near Oswestry. Puate 1X. Aulophyllum fungites (Flem.). Sections illustrating rejuvenescence, ete. Figs. 1a—Ic. Transverse sections of a coral displaying rejuvenescence; la & 1b are cut below the point of rejuvenescence, and 1¢ about that point (at a, b, & cin text-fig. 8, p. 73). x 1d. Fig. 2. Vertical section of another coral showing the same phenomena. X 1°5. Quart. Journ. Geot. Soc. Vor. LXIX, Pr.V. W. Ta ms, Photo. Bemrose, Collo., Derby. AULOPHYLLUM. Quart. Journ. Geot. Soc. Vor. LXIX, Pt. VI. ae y 4 ie RS KY ty gas ay AN cy) “i eat Fes Bemrose, Collo., Derby. W. Tams, Photo. AULOPHYLLUM. L All figures magnified by |.5.] 5 Sea Quart. Journ. GEoL. Soc. VoL. LXIX, PL. VII. q e eX Bat =] + eRe ip - A) rf ls a Cy v¢ C\a XN W.Tams, Photo. Bemrose, Collo., Derby. AULOPHYLLUM. a [ All figures magnified by 1.5. ] Quart. Journ. Geor. Soc. Vor. LXIX, PL.VIII. ALT) MES 4 i A fi; bi Bemrose, Coilo., Derby. W. Tams, Photo, AULOPHYLLUM. L All figures magnified by |.5.] Quart. Journ. Geor. Soc. Vor. LXIX, PL.IX. le.x 1.5 SX : ‘i et “4 a Np man ins. 3b. xi.5 Bemrose, Collo., Derby. W. Tams, Photo. AULOPHYLLUM. WelGo.)) ) THE GENUS AULOPHYLLUM. a Figs. 3a & 3. Transverse sections of a third specimen in which rejuvenescence has taken place. Fig. 30 is cut through the point corresponding to R..R in text-fig. 8 (p. 73), and 3a is cut about 3 mm. below that point. Between 3a and 3 6 considerable reduction, both in number and in length of the septal lamelle, has taken place. Xx 1°5. Section illustrating stereoplasmic thickening. Fig. 4. Vertical section through septa, showing the ster eoplasmic thickening of the septa and dissepiments i in the cardinal quadrant. xX 5. All from Peterhill Quarry, Bathgate. Discussion. Dr. A. VaveHan complimented the Author upon the detailed manner in which he had studied a group of highly-specialized Clisiophyllids, and felt sure that the paper would assist materially in the elucidation of many obscure points in coral-development. From the excellent figures shown by the Author it appeared that, as soon as any definite septal plan could be asserted, the coral already possessed the essential characters of the genus. He thought that the conspicuous irregularity of the very earliest stages might equally well be attributed to imperfect reminiscence of ancestral characters, or to mere youthful plasticity ; and he considered that a great number of Aulophylla must be cut through their earliest stages before the truth is arrived at. With regard to the structure of the coral, from the fact that the tabulx rise at the Aulophyllum wall, he thought that it would be impossible to demonstrate the continuity of the septa across that wall by hori- zontal sections alone. He considered that the structures shown in one figure, and said to illustrate reyuvenescence, might be explained as a case of breakage followed by subsequent mending. Finally, he enquired whether the Awlophylia could be employed to deter- mine levels within the Yoredalian, which was a long period and had as yet resisted faunal subdivision. The AvrHor, in reply, stated that he was able to recognize forms from D, as distinct from those which were found in the Upper Dibunophyllum Zone, but could not differentiate between those characteristic of D, and D,; hence he was unable to use them for the purpose of subdividing the Yoredales. He wished to point out that he termed the stage of development B, the ‘ Zaphrentoid Stage’ and not ‘ Zaphientis Stage,’ and said that he had not found any stage which corresponded to Cyathophyllum. He was certain, however, that the septa entered the central column in Stage C. With regard to Dr. Vaughan’s question concerning the possibility of the corallum having been broken and then repaired, he thought that the evidence pointed more strongly to the erection of a newer upon an older structure. In conclusion, he expressed his obligations to all those who had so generously placed material at his disposal, and also thanked the many friends who had aided him with information and suggestions, especially Mr. R. G.Carruthers, Mr. W. D. Lang, and Dr. A, Vaughan. 78 MR, E, PROCTOR ON FOSSILIFEROUS OLD RED [March 1913, 6. Nores on the Discovery of Fosstimerous Orn Rep SanpstonE Rocks mm a@ Borine at Sourwary, near Eatine. By Ernest Procror, A.R.C.S. (Communicated by Prof. W. W. Warts, Se.D., F.R.S., V.P.G.8. Read November 6th, 1912.) Introduction. In 1911 my attention was called to a boring at the works of Messrs. Otto Monsted & Co. at Southall. The work was carried out by Messrs. Isler & Co., and I wish to express my indebtedness to the firms in question for the facilities granted for the examina- tion of cores, and for permission to publish my conclusions thereon. The examination of the rocks was carried out in the Geological Laboratories of the Imperial College of Science & Technology, and the determination of the bulk of the fish-remains was made by Dr. A. Smith Woodward, who has added an appendix on them to this paper. I am also indebted to Dr. D. H. Scott and to Mr. A. J. Maslen for examining certain problematical fossils, which are probably of vegetable origin. Southall is on the Great Western Railway, about midway hetween Paddington and Windsor. ‘The position of Messrs. Otto Monsted & Co.’s factory is about 100 yards south of Southall Station (G.W.R.). The purpose of the well was to obtain water from the Lower Greensand, which had been struck and yielded copious supplies of water at Slough, 9 or 10 miles farther west. As will be seen; the well was a failure from this point of view, as the boring passed from the Gault directly into Paleozoic rocks. But to the geologist the result is of considerable interest, because of the new light thrown by it on the age of the Paleozoic rocks of the London area. Particular reference is made in this paper to Prof. Judd’s memoir ‘ On the Nature & Relations of the Jurassic Deposits which underlie London.’! Copious references to the literature, as well as an admirable summary of the conclusions reached, are to be found in Mr. Whitaker’s ‘ Geology of London’ Mem. Geol. Surv. (1889). In the ‘Report of the Royal Commission on Coal- Supplies’’ Dr. A. Strahan & Prof. O. T. Jones give a table and map (Appendix iv) of ‘the more important borings, throwing light on the possible occurrence of concealed coalfields, with references to published accounts. It is, therefore, needless to go any further into the bibliography of deep borings. 1Q. J. G. 8. vol. xl (1884) p. 724. 2 Final Report, pt. ix (1905) pp. 36-45. 7 Vol. 69.] SANDSTONE IN A BORING AT SOUTHALL. 79 The Tertiary and Secondary Rocks. Unfortunately, my attention was not called to the boring until Paleozoic rocks had been reached, and all the cores of the super- incumbent rocks had been removed. Messrs. Isler, however, have kindly supplied a record of the rocks passed through, and also allowed me to examine small samples of the cores kept by them. In the absence of fossils it is, of course, impossible to draw the exact limits of the various formations passed through. The engineer’s record is therefore printed in the sequel, and approxi- mate lines of demarcation are drawn on the evidence that exists. Mr. Mears, the engineer, informed me that there was only about 6 inches of what might represent the Upper Greensand ; while, from my own observation, I can confirm the entire absence of the Lower Greensand. The Gault, with a layer of. phosphatic nodules at its base, rested directly upon the red rocks to be immediately described. As the thickness of Chalk given in the journal is about 100 feet less than at the Richmond boring, it is practically certain that some of the rock marked ‘Blue Gault’ is in reality part of the Chalk, The Paleozoic Rocks. These rocks were struck at a depth of 1130 feet, and continued with slight variations down to 1261 feet, the final depth of the -boring. There is so close a resemblance between them and the ‘red rocks’ of the Richmond borehole that Prof. Judd’s description of the latter holds for the former. They consist of red and green mottled clays and sandstones, with occasional bands of fine con- glomerate. Mica is a very abundant constituent; particles of ‘galena occur; and, upon microscopic examination, minute rhombo- hedra of dolomite proved to be fairly abundant. Large quantities of the core were broken up, with the result that fossils were found. ‘These were present in a marked type of rock, which occurs in bands varying from about | inch to an eighth of an inch in thickness. It consists almost wholly of organic remains, associated with rounded and subangular pebbles of quartz. The principal fossils are the remains of fishes, which are fortunately preserved in sufficient perfection to enable Dr. Smith Woodward to make generic determinations of them. They consist of scales and teeth of Holoptychius, and plates of Bothriolepis. Both these genera are characteristic of the Upper Devonian or Old, Red Sandstone. The appendix by Dr. Smith Woodward (p. 81) gives a description of the more important of these remains. Other fossils were found, but for the most part they are of too fragmentary a nature for determination. In the microscopic slides, however, minute bodies which are probably plant-remains are to be seen. These were submitted to Dr. D. H. Scott and Mr. A. J. Maslen. Dr. Scott remarks that they are unlike any Deyonian plants with which he is acquainted, and suggests that 80 MR. E, PROCTOR ON FOSSILIFEROUS OLD RED _—‘[ March 1913, some of them may be sections of calcareous alge built up of a number of fine tubes. Calcareous Siphonie are certainly known from as far back as the Devonian Period. Record of Rocks passed through. The record of the boring given by Messrs. Isler is as follows :— Thickness Depth in feet. in feet. Made ground /f Brown clay ........... -..cecss0e+-0+- 6 6 and 4 Creanyell aiaGl sNC! coocoaeesscpeaseeanes 20 26 alluvium. (@Brownielayaeeeese eee eee eee eeereee 1 27 IoOmE@m Olay coo IBNe Cla? so000s20000seseconcnceos0s00s2 196 223 (eBlacks pebbles meses seeesseeeeee eee eee 1 224 ! IMIOAIEC| CIENT con002000002002 0300n00000° 16 240 . nu im ti woes ©” | Yellow mottled Claygate eee 10 250 te RES 4 Mottled clay and pebbles............ 12 262 Thanet Sands, | Sandy mottled CLAY petecneccosesteee 22 284 ? || Dares gemchy CIA socscasocdoconsennsce 3 287 { Loamy green sand .................- 8 295 Gree (@ Walleye Mee cmtaaaee cnssece 5: ae pene eaecs 107 402 ata Grae garteniens | Grey chalk ........... Pras tte, ee 466 868 (Cre WNs \ ceccoascedos IBGE erullinas aeoodasonucoucesasacsencoae 262 1180 Devonian ...... Redmar) soi, sto bas cosesneen cee re 97 1227 [This record would appear to have been made when the boring had only reached 1227 feet. A record of the boring, with a slight variation in the figures for the Chalk and Gault, has been published by the Geological Survey since the reading of this paper: see ‘ Records of London Wells’ Mem. Geol. Surv. 1913.] Conclusions. (1) The absence of anything corresponding to the Lower Green- sand might perhaps have been anticipated. In his Presidential Address to the Geological Society in 12V0' Mr. W. Whitaker pointed out that, while this formation is present in all the borings east of the River Darent in Kent, it is thinning towards the west. It is present at Crossness, and is only 10 feet thick at Richmond. As the Lower Greensand is absent at Southali, it appears strange that it is present at Slough in sufficient thickness to yield large quantities of water. In this connexion, it is interesting to notice that Sir Joseph Prestwich * held the view that the old Palseozoic land was of the nature of a ridge, with breaks in it at intervals. He wrote :— ‘I cannot imagine but that, from the very peculiar mineral character of the mass in Bedfordshire and Surrey, there must have been, in places, continuity between these areas, and I therefore infer that the Lower Greensand may yet be found under the Chalk at many places, and that, although not immediately under the north of London, it yet will be found at no great distance both to the north and south of that spot.’ 1 Q. J.G.S. vol. lvi (1900) pp. Ixxviii-lxxix. 2 Jbid. vol. xiv (1858) pp. 251-52. Vol. 69. | SANDSTONE IN A BORING AT SOUTHALL, 81 The presence of the Lower Greensand at Slough seems to indicate that here we have a break, perhaps of the nature of a bay or other inlet, into the Paleozoic land. .On the other hand, it may be that the Paleozoic mass, instead of continuing in an east-and-west direction as generally assumed, may here swing round to the north and join up with the Charnian axis. (2) The determination of the ‘red rocks’ at Southall as un- doubtedly of Old Red Sandstone age throws new light on similar rocks recorded from other localities in the London district. In the absence of fossils, all the evidence brought forward by Prof. Judd for the post-Carboniferous age of the ‘red rocks’ of the Richmond boring would apply equally to the Southall rocks; and this con- clusion would have been strengthened by the discovery of dolomite rhombs from the latter locality, an occurrence hitherto best known from Keuper beds. As no fossils were found at Richmond, Cross- ness, or Kentish Town, Prof. Judd was driven to make the utmost of a careful lithological comparison with both Old Red and New Red rocks, on the Continent as well as in this country. The result of tlfis comparison, confirmed by eminent foreign geologists, was that there seemed to be a closer resemblance to post-Carbon- iferous than to pre-Carboniferous rocks. Prestwich, however, preferred to consider that the ‘red rocks’ were of Devonian age, and many later geologists have consistently spoken of them as Old Red Sandstone, despite the difficulty created by the presence of undoubtedly marine Devonian rocks in other borings under London. Thus in the Royal Coal Commission’s Report, already cited, these rocks are referred to as ‘Old Red Sandstone?’ or ‘[Old Red Sandstone ?].’ But such determinations always failed to com- mand complete confidence, because of the want of paleontological evidence. Now that all doubt is removed in this one instance, it may very well be considered that the rest of the ‘red rocks’ are also of Old Red Sandstone age. (3) The occurrence of particles of galena in both the Southall and the Richmond rocks, together with the occurrence of dolomite crystals in the former and sodium chloride in the latter, indicate that the waters in which they were deposited were fairly con- centrated. Again, the Southall rocks bear little resemblance to the undoubted Devonian rocks from the Tottenham-Court Road and Turnford borings, nor have they yielded any of the marine fossils found at the other two localities. Apprnpix.—Note on the Fisu-RemaiIns from the Upper Devonian. By Arraur Suirx Woopward, LL.D., F.R.S., F.LS., Sec.G.8. [PuarE X.] Tur red sandy clay contains abundant fragments of the bony dermal armour of fishes, but most of these are too small for determination. When examined with an ordinary lens, a few Q.3.G.8. No. 273. G 82 DR, A, Ss WOODWARD ON FISH-REMAINS [March 1913, smooth granular pieces appear to resemble the tubercles of Thelodus ; but in section under the microscope all the specimens distinetly exhibit bone-cells, and so belong only to higher types of fishes. In all cases the bone-cells occur between parallel lamine, not arranged in haversian systems, the bony tissue being thus of the primitive type described by Pander as isopedin. A few fragments are larger than the others, and among these, as already recognized by Mr. Proctor, there are characteristic remains of Holoptychius and Bothriolepis. One elongate ovoid scale nearly 3 em. in length (Pl. X, fig. 1) shows in impression the typical external ornament of Holoptychius. The longitudinal ridges are large and few, thick and rounded as in H. nobilissimus, not so thin and sharp as in H. flemingi. They are rarely bifurcated and intercalated, and none are subdivided into tubercles. Their arrangement corresponds closely with that of the ridges on some ventral caudal scales in the type-specimen of H., nobilissimus from Clashbennie (Perthshire). Part of the inner face of the same scale is preserved, exhibiting a peculiar pitted and reticulated structure, which is seen again on the inner face of a second scale of smaller size and more nearly circular shape (Pl. X, fig. 2). It may also be added that twe or three fragments in microscope-sections of the rock display the curious chevron-pattern formed by the constituent laming, which has already been observed by M. Lohest* in a section of a thick scale of Holoptychius from the Devonian of Belgium. Part of the impression of a Holoptychian tooth, about 1 em. in height, bears marks of its fine longitudinal ridges, with the inter- calated more delicate ridges, extending nearly to the smooth blunt apex. Mr. Proctor made a transverse section of part of this tooth, and observed its dendrodont structure; but the specimen was unfortunately too fragile for preservation. Two portions of dermal plates clearly belong to Bothriolepis, as shown by their pitted external ornament and their cancellous structure (Pl. X, fig. 3). Equally thick plates of Holoptychius would be densely laminated, without any conspicuous cavities. In one specimen the superficial pits are smaller and more sharply defined than in the other, but similar variations may be noticed in different parts of the shield of one and the same species of this genus. An internal impression of another piece of dermal armour also seems to be referable to Bothriolepis, and may almost certainly be interpreted as a right posterior ventro-lateral plate. It is bent along its longer axis at an angle somewhat greater than a right angle; and the margin of the excavated hinder end shows the. impression of a wide rounded thickening on the inner face, which would strengthen this part. Traces of the bone itself are seen, and they bear the characteristic pitted ornament. 1 Ann. Soc. Géol. Belg. vol. xv (1888) Mém. p. 128 & pl. ii, fig. 4. Quart. Journ. Geor. Soc. Vor. LXIX, PL. X. Fig. IL, x 3 diameters. Fig. S), x 3 diameters. Raa? Bemrose, Collo.. Derby. E.Proctor, Photo. HOLOPTYCHIUS & BOTHRIOLEPIS from the SOUTHALL Boring. Vol. 69.] FROM A BORING AT SOUTHALL. 83. Holoptychius and Bothriolepis occur together in the Upper Old Red Sandstone of Morayshire and Fifeshire; in a corresponding formation north of St. Petersburg (Russia); and in the Catskill Formation of Pennsylvania (U.S.A.). Holoptychius is also met with in the Upper Devonian of Belgium, while Bothriolepis is know from a yellow sandstone just below the Carboniferous Limestone of Farlow (Shropshire). The remains found in the red sandstone ir the Southall boring, therefore, although so fragmentary, are enough to indicate its Upper Devonian or Upper Old Red Sandstone age. EXPLANATION OF PLATE X. [All the figures are magnified 3 diameters. | Fig. 1. Scale of Holoptychius sp., from within, the exposed portion shown irr impression on the matrix. 2. Scale of Holoptychius sp., mner face. 3. Dermal plate of Bothriolepis sp., the ornament shown in impression on the matrix. Discussion. The Prusipenr (Dr. A. Srrawan) commented on the difficulty of the search for fossils which had been brought to so successful an issue by the Author. He had himself always been of opinion that the red strata present in the borings at Richmond, Streatham, Crossness, Willesden, Chiswick, and Southall were of Old Red Sandstone age, and had so classed them in the table of borings published by the Royal Commission on Coal-Supplies. This, however, was merely an opinion, founded on a lithological resem- blance with the rocks of South Wales. The definite proof of the: existence at Southall of those upper beds of the Old Red Sandstone: which pass up into the Carboniferous was of great value. Dr. J. W. Evans congratulated the Author on the excellent use: that he had made of the opportunity afforded by the boring, which. he only heard of by a happy chance. He suggested that the law: should require that full information with regard to borings should: be given to the Geological Survey. He thought that the association of Old Red Sandstone and Devonian types could hardly be described as a new fact in the geology of this country. It occurred in the South of Ireland, in Pembrokeshire, and, above all, in North Devon, where three: separate occurrences of typical Old Red Sandstone were succeeded. by marine Devonian. The two are also associated in the Psam- mites de Condroz in Belgium, where some beds contain Holoptychius: and Asterolepis, and others a fauna allied to that of the Lower Pilton Beds. The Southall cores were compared with the Pickwell-Down. Sandstone, in which obscure fish-remains have been found = and itr was suggested that they were probably younger than the Frasnian of the Tottenham-Court Road boring and older than the cores of the Turnford bore, which contained a Lower Pilton fauna, 6 2 84 THE OLD RED SANDSIONE AT SOUTHALL. _[ March 1913, An important feature of the Devonian rocks below the Thames Valley was that all the three fossiliferous localities were of Upper Devonian age: this might have been expected. The Upper Devonian rocks of West Somerset were believed by the speaker to overlap the Devonian rocks below them, and in the Mendips and at Tortworth the Upper Old Red Sandstone rested on the Silurian ; while in the Bassin de Namur and the Boulonnais the Stringo- cephalus Beds at the summit of the Middle Devonian, succeeded by the Upper Devonian, rested with a conglomeratic base on much older rocks. He also alluded to the serious loss that geologists would suffer from the substitution of the chisel-drill for the diamond-drill, which appeared probable in borings for water and other purposes. Dr. H. Lapworts said that the suggestion of the previous speaker, that records of all British borings should be lodged at the Geological Survey Office, was a good one; but it would be necessary to carry the matter a good deal farther than this, if the records were to be depended upon. The journals of borings were kept by men who were often more or less uneducated, and possessed little or no knowledge of geology. In his own experience he had found that such records were not satisfactory. A Government control of boring records could only be efficiently maintained if the Geological Survey were notified before every boring was begun, in order that the journal should be made under geological supervision. The occasional use of the chisel in the process of boring was to be regretted by geologists ; but the borer himself was concerned solely with the cost, and in cases where cores are not demanded, the chisel, being cheaper in many materials than the rotary pro- cesses, was often largely employed. Mr. C. E. N. Bromeneap remarked that,according to Messrs. Isler’s account, the Gault was divided into two parts, the upper 125 feet {should be 121] being separated from the remainder by beds of sand. The suggestion was that this sand was Upper Greensand, and the upper part of the ‘Gault’ part of the Chalk. The total thickness of Chalk then amounted to 700 feet [should be 702]. It was most important that geologists should see the cores, and not be dependent on the well-sinkers’ accounts, which were a fruitful cause of scientific immorality. On a@ priori grounds he would have expected at least 700 feet of Chalk at Southall; he therefore interpreted Messrs. Isler’s record in the lght of a theory, and quoted the resultant reading as evidence in support of that theory. Vol. 69. ] PROF, A. C, SEWARD ON WEALDEN FLORAS. 85. 7. A Conrrizution to our KNowLepGE of WraLven Fuoras, with especial reference to a Cottection of Puants from Sussex. By Axserr Cuartes Sewarp, F.R.S., F.G.8., Professor of Botany in the University of Cambridge. (Read November 6th, 1912.) [Piares XI-XTV.] I. Introductory Remarks. In November of last year (1911) Mr. Charles Dawson, F.S.A., F.G.8., submitted to me for examination a small collection of plants obtained by him, with the able assistance of Father Teilhard de Chardin and Father Félix Pelletier, from the Wealden Beds of Sussex, for the most part from the neighbourhood of Fairlight. Several of the specimens, although specifically identical with. previously recorded types, are better preserved or larger than any hitherto found, and furnish new facts of importance. The collection includes also several new species. In accordance with Mr. Dawson’s wish, the specimens have been handed to Dr. Smith Woodward as a gift to the Geological Department of the British Museum (Natural History). With the exception of the example of Sagenopteris mantelli shown in Pl. XI, fig. 8, which is from the Ashdown Sands, the fossils in the Dawson Collection were obtained from the Fairlight Clay. In the descriptive section of this paper are included a few speci- mens from the Rufford Collection (collected at Ecclesbourne, near Hastings), acquired by the Museum subsequent to the publication of the Catalogue of Wealden Plants.! II. Description of the Specimens. EQUISETALES. Haoursetires LyELLI (Mant.). (Pl. XI, figs. 1a & 16.) (Near Fairlight, Wadhurst Clay ; Dawson Collection.) _ 1833. Mantell, ‘Geology of the South-East of England’ p. 245 & figs. 1-3. The specimen represented in Pl. XI, fig. la, though smaller than some previously figured from the Wealden Beds of Sussex, exhibits certain features worthy of notice. The incomplete inter- node has a length of 4 cm. and a breadth of 7 mm. A portion of a leaf-sheath is seen at the upper end with linear lanceolate teeth (fig. 16) showing a ragged carbonized border, which may be the remains of torn, transversely elongated cells, such as form the com- missural tissue in the leaf-sheaths of recent species. On the linear divisions of the sheath and on the free acuminate teeth the outlines ' Seward (94) & (95). These numerals in parentheses refer to the Biblio- graphy, § IV, pp. 112-15. £6 PROF, A. C. SEWARD: CONTRIBUTION TO [March 1913, ot elongated rectangular cells are clearly preserved (Pl. XI, fig. 1 6). The internode is longer than in previously-recorded specimens referred to this species. In its slender dimensions, and in the form of the leaf-sheath, the fossil agrees generally with Mantell’s species; but it differs in the greater elongation of the internode from the majority of specimens recorded from America,' Germany,’ and elsewhere. It is essentially similar in form to the shoots of existing members of the genus, and of narrower diameter than the common Jurassic species, Hquisetites columnaris Brongn. A very similar type is represented by #. vir- geuacum Font.,* which Mr. Berry believes to be identical with Dunker’s species, H. burchardti : while expressing some doubt as to the correctness of this view, I must admit that the line of demar- cation between H. lyelli and £. burchardti is not very clearly defined. Some specimens described by Dr. Neumann* from Peru as E. lyelli, whether or not correctly determined, appear to be of the same general type as that species. LYCOPODIALES. LycoPpopiITEs TEILHARDI, sp. nov. (Pl. XI, figs. 2a & 26.) (Fairlight Clay, Fairlight; Dawson Coll.) The fragment shown in fig. 2 a consists of a slender forked axis bearing two rows of alternate oval leaves, 8 mm. long, with a median vein. Superposed on the axis there appears to be a row of rather smaller leaves, a few of which are seen in fig. 26. The faint stain on the rock made by the short and broad leaves suggests comparison with the thin lamina of many species of Selaginella, and the apparent occurrence of dimorphic foliage points in the same direction. Despite the probability that the specimen is more closely related to Selaginella than to the genus Lycopodium, the generic name Lycopodites is adopted in preference to Selaginellites, in con- formity with Prof. Zeiller’s suggestion® that the latter designation should be reserved for plants in which heterospory has been demonstrated. An American species, originally recorded by Fontaine * and more recently described by Mr. Berry’ from the Patapsco Formation (Potomac) of Maryland as Selaginella marylandica, agrees closely with /. tedhardi, except in the absence of any indication of heterophylly. Berry (112) p. 311 & pl. xli, figs. 7-8. Scherk (71) p. 207 & pl. xxii, figs. 10-13. Fontaine (89) pls. i & ii; Berry (11°) p. 310. Neumann (07) p. 77, & pl. i, fig. 2. Zeiller (06) p. 141. Fontaine in Ward (05) pl. exv, figs. 9 & 10. Berry (11*) p. 3807 & pl. xli, figs. 1-2. RA Qi © eS Vol. 69.] OUR KNOWLEDGE OF WEALDEN FLORAS. 87 SELAGINELLITES DAWSONI, sp. nov. (Text-fig. 1, below.) (Fairlight Clay, Ecclesbourne ; Rufford Coll.) The specimen on which this species is founded occurs on a piece of ironstone, in close association with a sterile repeatiedly-branched shoot, identical with the impression represented in pl. 1, fig. 8, of the first part of the ‘ Wealden Flora’,’ and described as Planta incerte sedis. The fertile shoot consists of a ribbon-like axis 3 cm. long and approximately 2 mm. broad: at the edges of the axis are faint broadly-triangular impressions of sporophylls, and the median region bears numerous spherical sporangia. From the sporangia both megaspores and microspores have Fig. 1.—Selaginellites been obtained in an exceptionally good dawsoni, sp. nov., state of preservation: the spores have a (natural size). tuberculate outer wall. The microspores, which often occur in tetrads, are approx- imately ‘04 mm., and the megaspores *35 mm.,in diameter. Both spores closely resemble those of some recent species of Selaginella. In addition to the larger piece of fertile axis there is another fragment, the lower part of which is sterile and identical with the vegetative shoot pre- viously figured.2 The discovery of the spores, while confirming the former com- parison of the sterile specimen with a lycopodiaceous plant, demonstrates a closer affinity to Selaginella than to Lycopodium. It is proposed to publish an illustrated account of this species, which I have named after Mr. Charles Dawson, whose labours have materially added to our knowledge of the Wealden flora, in a forthcoming number of the ‘ New Phytologist.’ FILICALES. ? HypRopruriDEz. SAGENOPTERIS MANTELLI (Dunk.). (PI. XI, figs. 3 & 5.) (Ashdown Sands, near Fairlight ; Dawson Coll.) 1846. W. Dunker, ‘Monographie der Norddeutschen Wealdenbildung’ p. 10 & pl. ix, figs. 4-5. The British specimens of this species previously figured are rather smaller than those in the Dawson Collection. Fig. 5 shows portions of two relatively broad leaflets, with clearly-preserved anastomosing veins and a fairly definite midrib in the proximal part of the lamina, attached to a common petiole. Some of the leaflets figured by Dunker are identical in form with the Fairlight specimens, and similar examples occur in the Rufford Collection * Seward (94) p. 20. 2 Seward (94) pl. i, fig. 8. 88 PROF, A. C. SEWARD: CONTRIBUTION To [March 1913, (Natural History Museum). The fact that in the Jurassic species Sagenopteris phillips: (Brongn.) there is clear evidence of con- siderable variation in the size of the leaflets and in the extent and distinctness of the midrib, lends support to the view that a similar variability characterizes the Wealden type, of which there is less available material. In all probability, the larger leaflet shown in Pl. XI, fig. 3, which reached, when complete, a length of 7 cm. and has a much more distinct midrib than the shorter leafiets, is not specifically distinct from the example represented in fig. 5 of the same plate. The long and narrow meshes formed by the anastomosing veins are approximately 0-7 mm. in breadth. The close agreement between S. mantelli and S. phillips: is such as to render impossible a satisfactory separation in all cases; but, having regard to the average form of the leaflets, it would seem that in S. mantelli the lamina is usually shorter and broader than in the older form. A comparison of some specimens, recently described from the Kimmeridge Beds of Sutherland! as S. phillips’, with that represented in P]. XI, fig. 3 illustrates the difficulty of accurate determination. The specimens described by Fontaine and Berry* as S. elliptica from the Potomac Group, and compared by the latter with S. man- telli, agree very closely with the leaflet shown in fig. 3. The examples figured by Fontaine as S. elliptica,® from the Shasta Formation of California, are in all probability referable to S. man- telli. The imperfect fossils from South-Eastern Scania, probably of Middle Liassic age, compared by Dr. Halle * with S. mantelli, are too incomplete to be referred to that type with any degree ot certainty. SAGENOPTERIS ACULIFOLIA Sew. (PI. XI, fig. 4.) (Ecclesbourne, Rufford Coll.) 1895. A. C. Seward, ‘ Wealden Flora’ pt. 2, p. 228. The narrow leaflet represented in fig. 4 is characterized by a distinct midrib ; the lateral veins are obscure, but there are indi- cations of anastomosis. This specimen is similar in size and shape to one from the Hastings neighbourhood originally described as Phyllopteris acutifolia,? and afterwards, as the result of a re- examination of the impression, referred to the genus Sagenopteris. These narrow leaflets resemble the smaller forms of S. undulata Nath.,° and are very similar to some of the specimens from Suther- land included in S. phillipsi.” It is by no means unlikely that the leaflet reproduced in Pl. XJ, fig. 4 is specifically identical with the large examples shown in figs. 3 & 5 of the same plate. 1 Seward (11) pl. 1, fig. 1. ® Berry (11°) pp. 287-89. ° Fontaine in Ward (05) p. 286 & pl. lxv, figs. 59-40. 4 Halle (10) p. 8 & pl. i, figs. 18-21. ° Seward (94) p. 143 & pl. is, fig. 6. ® Halle (10) pl. i, fig. 3. 7 Seward (11) p. 656 & pl. i, fig. 4. Vol. 69.] OUR KNOWLEDGE OF WEALDEN FLORAS, 89 EUFILICINE. Matoninee. Maronrpium ce@rpertr (Ett.). (Pl. XIV, fig. 3a; text-fig. 2C, pe ol.) (Fairlight, Dawson Coll.) 1843. Cycadites althausii Dunker, Progr. d. h. Gewerbsch. Cassel, p. 7. 1852. Alethopteris gepperti Ettingshausen, Abh. k.-k. Geol. Reichsanst. vol. i, pt. 3, No. 2, p. 16 & pl. v. The older specific name althausii has been revived by Lester Ward,’ and this unfamikar designation is adopted also by Mr. Berry.” The latter author has recently instituted a new genus, Anowlton- ella,® for some fronds from the Potomac Group of Maryland, cha- racterized by a ‘ pseudo-dichotomous’ habit, a strong rachis, and linear-lanceolate pinnules, which he assigns to the Matoniacee ; but, in the absence of satisfactory fertile specimens, there would seem to be no adequate reason for this reference. The portions of fronds on which the genus Knowltonella is founded bear a close resemblance to Phlebomeris spectanda Sap. from the Albian of Portugal.* The specimens of Matonidium gepperti in the Dawson Collection show more clearly than any English examples so far described the habit of the frond and the arrangement of the comparatively large contiguous sori on the under surface of the pinnules. One of the few spores obtained is reproduced in text-fig. 2 C (p. 91); it is triangular in shape, with broadly rounded corners, and is approxi- mately -06 mm. in diameter; the wall is thick and smooth, and is often more or less: depressed along the sides. In the example figured the wall has separated along the three-rayed ridge, leaving a central space. ‘The spores agree closely with some obtained from a pinna of Matonidium from the Middle Jurassic beds of the Yorkshire coast, for which I am indebted to Mr. Hamshaw Thomas, and are of the same type as those figured by Schenk ® from the Wealden of Germany. Dipteridinez. HAUsMANNIA PELLFTIERI, sp. nov. (PI. XIV, figs. 1-3.) (Fairlight, Dawson Coll.) The genus Hausmannia, founded by Dunker ° on leaves from the Wealden Beds of North Germany, has not hitherto been recognized with certainty in the Wealden flora of England. It is owing to the zeal and skill of Fathers Pelletier & Teilhard de Chardin that I am now able to describe some particularly good specimens of ' Ward (99) p. 653. 2 Berry (112) passim. 3 Berry (11°) p. 253 & pls. xxv-xxvii. + Saporta (94) p. 168 & pl. xxx, fig. 1; Zeiller (08) p. 192, fig. 7. Schenk (76) pl. xxvii, figs. 9b & 9c. Dunker (46) p. 12. a o 90 PROF. A. C, SEWARD: CONTRIBUTION to [ March 1973, this interesting fern. The frequent association of Hausmannia and Matondium in the Fairlight Clay (Pl. XIV, fig. 3 a) bears striking testimony to the fact, that the association on Mount Ophir in the Malay Peninsula of the genera Dipteris and Matoma is a survival at the present day in the Southern Hemisphere of a sample of European Wealden and Jurassic vegetation. There can be little doubt as to the very close affinity of these two geographically - restricted existing genera to the fossil species of Hausmannia and Matonidium. The fronds of Hausmannia pelletieri vary in size from the deeply-bilobed form, 2 cm. broad, represented in PJ. XIV, fig. 2 (thrice the natural size), to the larger and more dissected type reproduced (natural size) in fig. 3 of the same plate. The lamina of the smaller leaf bears a close superficial resem- blance to asmall form of Ginkgo biloba L. or G. digitata (Brongn.): in the larger fronds (as, for example, fig. 3) the lamina is divided into obcuneate segments, characterized by a few strong ribs and a reticulum of finer veins. The forked main ribs spread from the summit of a fairly long petiole (fig. 2); from them numerous branches are given off at right angles, and the finer veins form an irregular reticulum with the ultimate branches ending blindly in the polygonal areas. The species Hausmannia kohlmanni, founded by the late Dr. Richter’ on material from the Lower Cretaceous strata of Strohberg, in Germany, differs from H. pelletieri in the less deeply- cut lamina and in the more entire margin. The smaller German species, H. sewardi Richt.* is distinguished by its entire and obovate lamina. The frond shown in Pl. XIV, fig. 3 closely resembles some forms of H. dichotoma*; but in that species the segments are usually narrower than in //. pelletiert, and the leaves reach larger dimensions. Comparison may also be made with Barthoiin’s Lower Jurassic species H. forchhammeri,* and with H. crenata Nath., as figured by Moller’?: both from Bornholm. The fragments described by Schenk from the German Wealden as Dictyophyllum remeri® are, in all probability, correctly referred to that genus rather than to Hausmannia: on the other hand, Heer’s Dictyophyllum dicksoni* from the Kome Beds of Greenland may be a piece of a Hausmaninia frond. It is also probable that some of the fragments described in Part I of the British ‘ Wealden Flora’ as Dictyophyllum reemeri should be removed to Hausmannia; andthe same statement applies to a specimen figured from the Wealden of Bernissart as Protorhipis roemer.” Richter (06) p. 21 & pls. i, ii, v. Ibid. p. 22 & pl. 1, fig, 12; pl. v, figs. 3-4. hoo Heer (74) pl. iii, fig. 9. Seward (00) p. 18 & pl. iui, fig. 34. 2 Seward (11) p. 657 & pl. i, figs. 14-17, 19; pl. ii, fig. 20. 4 Bartholin (92) pl. xi. > Moller (02) pl. v, figs. 5 & 6. 6 Schenk (71) pl. xxxi, fig. 3 & pl. xxxvi, figs. 7 a—7 0. — Vol. 69. ] OUR KNOWLEDGE OF WEALDEN FLORAS. 91 Schizeacez. RurFFoRDIA G@PPERTI (Dunk.). (Text-fig. 2 A, below.) (Fairlight, Dawson Coll.) 1846. Sphenopteris gepperti Wunker, ‘ Monographie der Norddeutschen Wealdenbildung’ p. 4 & pl. i, fig. 6 ; pl. ix, figs. 1-3. 1894. Ruffordia goepperti Seward, ‘ Wealden Flora’ pt. 1, p. 76. The Dawson Collection includes a piece of fertile frond of the same type as one prewiously figured from the Hastings district,' and from this a few spores were obtained by treatment with Schulze’s solution. The spores are ‘05 mm. in diameter, and have a rounded triangular form, the surface being characterized by the presence of numerous ridges (text-fig. 2 A): they agree in shape Fig. 2.—Spores of (A) Ruffordia gcepperti ; (2) Pelletieria valdensis; and (C’) Matonidium geepperti (all considerably enlarged). Cc and sculpturing with those of certain recent Schizeaceous ferns, and are similar to the spores of Mr. Berry’s Potomac fern Schize- opsis americana.” In his earlier paper in the ‘ Annals of Botany’ the fern which he afterwards named Schizwopsis americana was regarded as specifically identical with Bateropsis eapansa Font., and referred to as Schizewopsis expansa. The spores of the recent species Ancimia tomentosa Sw. and Mohria caffrorum Desv., which are of the same type as those of Auffordia, measure respectively Q-1 mm, and 0°8 mm. in breadth. No sporangia have been found ; but the structure of these spores supports the inference, based on the habit of the fertile and sterile lronds, as to a Schizzeaceous alliance. PELLETIERIA VALDENSIS, gen. et sp.nov. (PI. XII, figs. 12a & 126; Pl. XIV, fig. 5. Also text-figs. 2B, 3, & 4.) (Fairlight Clay, Dawson Coll.; near Hastings, Rufford Coll.) The specimens on which this new genus is founded do not afford sufficient data on which to base a complete diagnosis, nor do they 1 Seward (94) pl. v, fig. 5. ? Berry (11) pl. xii; éd. (11?) pl. xxii, figs. 4-9. 92 PROF, A. C. SEWARD : CONTRIBUTION TO [March 1913, supply such evidence as is needed to establish definitely the affinity of the plant. The specimens which first attracted my attention are those represented in Pl. XII, fig. 12 a and in text-fig. 4 (p. 93), and a search through the Rufford Collection led to the discovery of the larger specimens of the same type reproduced in text-fig. 3, below. As all the examples are clearly of the same type, a single diagnosis may serve for genus and species. Fertile fronds, with little or no sterile lamina, consisting of a slender main axis giving off lateral branches at an acute angle which bifurcate repeatedly, the ultimate ramifications being very thin aud divergent (text-fig. 3 B). At the tips of the fertile branches are borne more or less spherical carbonized bodies, approximately 2 mm. long, enclosing a very large number of tetrahedral spores 60 to 70 yw in diameter, and characterized by well-defined surface-ridges (Pl. XIV, fig. 5 & text- . 3.—Pelletieria valdensis: A, B, B’ =preces of fertile fronds ; C=two spore-masses. fig. 2 B), and a form of sculpturing met with in recent species of Schize- aceze and in the tropical water-fern Ceratopteris. There is no conclusive evidence in regard to the nature of the sterile pin- nules, but the juxtaposi- tion of some narrow cuneate segments’ (text- fig. 4 G, p. 93) may be an indication of their form. No sporangia have been recognized. The imperfect and bro- ken specimen represented of the natural size in text-fig. 3 B, affords the best example of the habit of the fertile frond; at the apices of a few of the branchlets are portions of the spore-masses. Berry (11?) p. 257. 96 PROF. A. C. SEWARD: CONTRIBUTION TO [March 1913, It is, however, hardly possible, at least in some cases, to dis- tinguish between the species Cladophlebis browniana and Klukia exilis (Phill.). Prof. Zeiller’ has recently recorded the occurrence of fertile pinne of a fern from the Wealden of Peru, which he regards as closely allied to Pecopteris browniana; and a fern from the same country figured by Dr. Salfeld? as Cladophlebis sp., cf. Coniopteris arguta Lind. & Hutt., appears to be identical with Cl. browniana. The same remark is applicable to this author’s Pilicites (? Aletho- pteris) ellensis. It is interesting, in view of the close agreement between Klukia evilis® and Cl. browmana, to find that Prof. Zeiller speaks of the fertile pinne of his Peruvian fern as possessing ovoid sporangia of the Schizzeaceous type. Polypodiacez. ONYCHIOPSIS MANTELLI (Brongn.). (Fairlight, Dawson Coll.) 1824. Hymenopteris psilotoides Stokes & Webb, Trans. Geol. Soc. ser. 2, vol. i, pt. 2, p. 424 & pl. xlvi, fig. 7. 1828. Sphenopteris mantelli Brongniart, ‘ Histoire des Végétaux Fossiles ’ p- 170 & pl. xlv, figs. 3-7. This species is represented by a clearly-defined impression, in which the ultimate segments are a little larger than in most of the previously recorded examples, but slightly smaller than the pinuules of specimens referred to Onychiopsis elongata (Geyl.) in Part I of the ‘ Wealden Flora.’ The American authors Ward * and Berry ’ have adopted for this species the name Onychiopsis psilotoides (Stokes & Webb); but, in view of the long usage of the designation mantelli and the frag- mentary nature of the fossil figured by Stokes & Webb, I retain the more familiar name. A re-examination of the English material led me to regard the forms previously assigned to the two species O. mantelli and O. elongata as one species. Mr. Berry has, however, examined some of the Japanese fossils described by Dr. Yokoyama as O. elongata, and his view is that they are not specifically identical with the Potomac plant referred to O. psilotoides. This author includes O. elongata in his synonymy of O. gepperts (Schenk). KUFILICINEH INCERT#® SEDIS. TEILHARDIA VALDENSIS, gen. et sp. nov. (PI. XI, figs. 7 a—9 6.) (Fairlight Clay, Keclesbourne, near Hastings; Rufford Coll.) The fertile impressions represented in Pl. XI, figs. 7 a—9 6, occur 1 Zeiller (10). 2 Salfeld (09) p. 214 & pl. iii, fig. 4. 3 For figures of Klukia, see Raciborski (94) pl. viii, figs. 1-3, 7-9; also Seward (12) pl. vi, fig. 81 & pl. vii, fig. 88. 4 Ward (05) p. 159. > Berry (11) p. 274. Vol. 69.] OUR KNOWLEDGE OF WEALDEN FLORAS. 97 together in some small pieces of ironstone from Ecclesbourne, and there is no doubt as to their specific identity ; the form of pinnule shown in Pl. XI, fig. 9 ais connected by transitional stages with that reproduced in figs. 7a & 8a, and the sori in both kinds of pinnules are the same. No sporangia or spores have been found. The longer and narrower type of fertile pinnule (fig. 7 ) reminds one of those of OCladophlebis browniana and Klukia exilis ; but the size of the elliptical patches on each side of the midrib suggests sori rather than the single sporangia of Alukia. Moreover, the pinnules are more erect in the Wealden specimens, and the segments seen in Pl. XI, fig. 96 are distinct from any observed in Cl. browniana and Klukia exilis. Although the data are inadequate for accurate determination of affinity, I venture to institute a new generic name, after Father Teilhard de Chardin, for this Wealden fern, which differs in certain respects from any known type. Frond tripinnate; pinne linear, alternate; pinnules on the smaller branches more or less deltoid, with obtuse apices; other pinnules linear and relatively narrower, entire, or crenulate (fig. 86), and attached almost at right angles to the pinna-axis. Venation very imperfectly preserved: as already stated,no sporangia or spores have been discovered. Frum incerte sedis. (Pl. XI, fig. 10.) (Near Hastings, Rufford Coll.) The specimen shown in fig. 10 is described in Part I of the ‘Wealden Flora’’ as probably a fragment of Sagenopteris mantelli accidentally associated with a rachis-like axis. A more careful examination leads me to regard the leaflets as pinnules of a fern, In association with a piece of rachis to which the lower leaflet is attached. There is a clearly-marked midrib, as also numerous secondary veins which are obscurely preserved : the lamina is con- tracted at the base, and agrees in shape with that of Neuropteris pinnules. Comparison may be made with a specimen figured by Schenk from the Wealden of Germany as Alethopteris huttom,? and with Cladophlebis constricta Font.’ It is possible that these pinnules were borne as Aphlebia-leaflets on the petiole of a fern which possessed pinnze with smaller pinnules ; but there is nothing to support this suggestion, except the analogy of some Paleozoic fronds. 1 Seward (94) p. 134. 2 Schenk (71) pl. xxix, fig. 1. [Since the above description was written, it has been pointed out by Herr Huth that Newropteris huttoni Dunk. (= Alethopteris huttoni) is a fragment of the Carboniferous species Mariopteris muricata: see Zobel (12) p. 262. Herr Zobel has identified the specimen figured by Schenk as Marsilidium speciosum, and included by him as a Wealden type, as Sphenophyllum thoni Mahr.] 3 Berry (11?) p. 246 & pl. xxix, fig. 3. Ae de Cin tsi) Noy Hes H 98 PROF. A. C. SEWARD : CONTRIBUTION To [March 1913, ApuiesBia sp. (Pl. XIV, fig. 4.) (Fairlight Clay, Ecclesbourne ; Rufford Coll.) The irregularly dissected leaf-like organ shown in fig. 4 (4 em. x 3°3 cm.) has no well-defined veins; but the surface is characterized by numerous spreading striations or wrinklings, which may be the result of contraction. A specimen described as Aphlebia from the Upper Jurassic beds of Sutherland* has been compared with the stipules of recent Marattiaceous ferns, and it is not unlikely that the Wealden fossil is of this nature. In size, as also in the uneven margin, the specimen agrees closely with the stipules of Marattia fraximea.* Some ovate entire leaves with forked and spreading veins, recently described by Dr. Halle* from the Middle Jurassie beds of Yorkshire under a new generic designation, Cloughtonia, may be closely allied to the Wealden fossil. Halle is inclined to regard Cloughtonia as bracteal, and possibly borne on some highly- developed Gymnosperm ; he also suggests comparison with large Angiospermous petals. One cannot speak with any confidence as to the nature of these detached scales, but I am inclined to think that the comparison with stipular or aphleboid organs is the more appropriate. Some Wealden specimens from South Africa, described as Cyca- dolepis jenkinstana (Tate),* may perhaps be of the same general type as the English example. Planta incerte sedis. (? EUFILICINE. ) DicHOPrERIS DELICATULA, sp. noy. (Pl. XI, figs. 6a & 60.) (Fairlight, Dawson Coll.) The specimen on which this species is founded exhibits the following characters :—Rachis and axes of pinne relatively stout and prominent; pinne alternate. Pinnules alternate, with a fairly thick lamina, a deltoid or broadly-linear blunt apex, attached by the whole base ; no veins shown. The form of the pinne reminds one of species of Gleichenites, or of the Sussex specimens previously described under the name Leckenbya valdensis,* and subsequently referred to Gleichenites cycadina (Schenk)°; but Dichopteris delicatula is distinguished by the form of the pinnules, which show no sign of a lobed base, and by the absence of the Cladophlebis type of venation. Super- ficially, there is a fairly close similarity to some of the Sussex fossils described as Sphenopteris fittoni Sew.”; but in that species the pinne are shorter, the pinnules more acute and often lobed. 1 Seward (11) p. 674, text-fig. 6. * Seward (10) p. 317, fig. 41 B. 3 Halle (11). 4 Seward (03) pl. iv, figs. 3 & 4. > Seward (95) p. 225. ° Seward (11) p. 664. Seward (94) p. 107, pl. vi, fig. 2 & pl. vil, fig. 1. Vol. 69. ] OUR KNOWLEDGE OF WEALDEN FLORAS. 99 The fronds figured by Saporta from the Kimmeridgian of Orba- gnoux (Ain), and from Pertugal, as Scleropteris zeilleri’ agree very closely with the English type; and an equally close resemblance is presented by S. pomeli Sap.,7 a type recently recorded from Sutherland under the generic name Dichopteris, which was adopted in preference to Saporta’s generic term Scleropteris.’ CYCADOPHYTA. BENNELTITALES, WILLLIAMSONIA CARRUTHERS! (?) Sew. (Fairlight, Rufford Coll.) 1895. A. C. Seward, ‘ Wealden Flora’ pt. 2, p. 157 & pls. x—xi. A specimen in the Rufford Collection (V 3766), acquired by the British Museum (Natural History) since the publication of the ‘Wealden Flora,’ is worthy of notice as being probably a peduncle of W. carruthersi. Itis the impression of an axis 13 cm. long, which, with the exception of some crowded leaf-scars at one end, is characterized by the occurrence of narrow and rather widely-separated scars, probably marking the position of linear bracts. These scars are 2 to 2°5 cm. apart in a vertical line; they agree In size and shape with the bracts of the fructification of W. carruthers:.* The specimen may be compared with peduncles of Williamsonia from the Jurassic rocks of Yorkshire.’ If the assumption that this Wealden peduncle bore an apical flower of W. carruthersi is correct, it affords an argument in support of the adoption of the generic name Williamsonia in preference to Bennettites. CYCADOPHYTA INCERTA SEDIS. OrToZAMITES KLIPSTEINII (Dunk.). (Text-fig. 5, p. 100.) (Fairlight Clay, near Cliff End, Hastings ; Rufford Coll.) 1846. Cyclopteris klipsteini, Dunker, ‘Monographie der Norddeutschen Wealdenbildung’ p. 11 & pl. ix, figs. 6-7. 1895. Otozamites klipsteinii Seward, ‘Wealden Flora’ pt. 2, p. 60 & pl. 1, figs. 83-4; pl. vu. In the‘ Wealden Flora’ some specimens were referred to Dunker’s species, although the size of the pinne greatly exceeds that of the type-specimen and the examples subsequently figured by Schenk.* The specimen reproduced in text-fig. 5 (V 3709) affords 1 Saporta (91) p. 434 & pl. cclxxxviii (or Ixii), fig. 1; id. (94) p. 46, pl. x, fig. 2; pl. xi, figs. 14-15; & pl. xii, fig. 1. 2 Saporta (73) pl. xlvi, fig. 1 & pl. xlvii, figs. 1-2. 3 Seward (11) p. 678, pl. iu, fig. 55 & pl. iv, fig. 71 ; see also Seward (10) p. 552. 4 Cf. Seward (95) pl. x, fig. 1 & pl. xv, fig. 3. ® Saporta (91) pls. xv-xvii ; Seward (97); Wieland (11). ® Schenk (71) pl. xxxi, fig. 6. (Natural size.) .—Otozamites klipsteinii (Dunk.). Vol. 69. ] PROF. A. C. SEWARD ON WEALDEN FLORAS. 101 confirmation of the extension of Dunker’s definition of the species, to include pinne considerably larger than any obtained by him from German strata. Specimens of Otozamites similar to O. klipsteinti have reeently been figured by Mr. Hamshaw Thomas’ from Jurassic beds in Southern Russia. Crenis sp. (PI. XII, figs. 1a, 1b, & 2.) (Rufford Coll.) The pieces of linear pinnce represented in figs. 1 & 2, although too small to be assigned to a species, afford evidence of the occurrence of the genus Ctenis in the Wealden flora. The enlarged drawing (fig. 1 6) shows very clearly the Ctenis type of venation. A frond previously figured from the Sussex coast as (?) Zamutes sp.” was compared with Ctenizs, which it closely resembles in habit ; but no anastomosing veins were discovered. In all probability, that specimen is specifically identical with fronds from the Kimmeridgian beds of Sutherland, for which a new generic name, Pseudoctenis,*® has been instituted. CycADEAN STEMs. The Dawson Collection includes a few pieces of Cycadean stems, which agree generally, in the form of the leaf-bases or persistent scale-leaves, with Bucklandia anomala Carr.‘ One of them has rhomboidal leaf-bases, 2 cm. deep by 2°2 cm, in breadth, which are very similar to those on Jurassic stems assigned to Williamsonia gigas.’ Another specimen represents a narrow and incomplete stem 39 cm. long, with a few imperfect leaf-bases like those of Bucklandia, Yatesia, and Fittonia, genera which are not distin- guishable by well-defined characters. This and other examples of stems from the Sussex coast show that some of the Cycadean plants of the Wealden flora possessed long and narrow stems like those of some recent species of Cycas and the genus Microcycas ; and the absence of any fertile lateral shoots of the Bennettitean type is an interesting feature, pointing to the occurrence of flowers either at the apex of the main stem, or on elongated peduncles of the Williamsonia type. Kury-Cycapotrpis. (Pl. XII, figs. 3a-4¢; Pl. XIV, fig. 6; and text-fig. 6, p. 102.) (Fairlight Clay, Fairlight ; Dawson Coll.) In Part II of -the ‘Wealden Flora’ several specimens were cescribed under Saporta’s generic term Cyycadolepis, the broader 1 Thomas (11) pl. v, fig. 11 & pl. vi, figs. 1-2. ? Seward (95) p. 89, fig. 5. 3 Seward (11) p. 692. * Carruthers (70) pl. liv, figs. 1-3. 5 Williamson (70) pl. liii, fig. 5. A similar stem has been recorded from the Uitenhage Series (Wealden) of Cape Colony: Seward (07) pl. xxi, fig. 9, 102 PROF, A. C. SEWARD: CONTRIBUTION To [March 1973, and larger examples being referred to a sub-genus Eury-Cycadolepis.* None were found in connexion with stems. Additional examples of these scales were figured in an account of the Uitenhage Flora of Cape Colony.” The Dawson Collection includes several specimens of Hury-Cycadolepis, which supply some fresh information as to these curious organs. Fig. 6.—Eury-Cycadolepis sp. A § B= Casts of stems with scales (8S). (Half of the natural size.) The following descriptions are given, in the hope that further search may lead to the discovery “of specimens which will afford more decisive evidence as to the morphology of the scales :— Pl. XII, fig. 3a. This small scale, superficially recalling the test of a Terebratula, is covered at the narrow end with a fairly thick layer of coal which on magnification (fig. 3b) shows numerous striations roughly parallel to its long axis. Below the coal (fig. 3¢) is a reticulate pattern on which are superposed longitudinal striations similar to those on the carbonized surface. 1 Seward (95) p. 96. 2 Seward (03) pp. 31-82. Wolb Go.) OUR KNOWLEDGE OF WEALDEN FLORAS. 103 Pl. XII, fig. 4a. The scale, shown half of the natural size in fig. 4a, measures 106 cm.; it is slightly convex, and rather sharply bent down at the left-hand edge, while at the upper margin it 1s in organic connexion with a piece of woody axis. The dark band encircling an area near the centre is due to the presence of carbonaceous matter, and has no significance. Over the whole surface is a raised reticulum with meshes varying in size and shape (Pl. XII, figs. 4b & 4c): towards the right-hand edge this reticulum passes into irregularly anastomosing ridges (fig. 4c). This surface-sculpturing may be due to the shrinkage of a thick scale originally covered by a felt of hairs, as are the scales of Dioon and some other Cycads. Text-fig. 6 A (p. 102). This specimen (half of the natural size) consists of a sandstone cast of a portion of a stem with imperfectly preserved attached scales, one of which is shown at 8, The irre- gular sinuous lines in the upper part of the stem indicate the presence of other scales lying on the stem. Text-fig. 6 B (p. 102). In this example there is similar evidence of the attachment of scales (S, S) to a stem; and the occurrence of ridges and striations oblique to the stem suggests the former presence of a complete covering of scales. Pl. XIV, fig. G6. An imperfectly-preserved carbonized scale, like those shown in text-fig. 6 B and in Pl. XII, fig. 4a, when treated with Schulze’s solution, yielded pieces of cuticle showing numerous stomata and the outlines of very thick-walled epidermal cells. The stomata agree in the form of the guard-cells with those of recent Cycads. The additional information supplied by these specimens, although not sufficient to scttle definitely the systematic position of the fossils, gives some support to the opinions expressed in Part II of the ‘ Wealden Flora.’ Planta incerte sedis. CoNITES BERRYI, sp. nov. (PI. XII, fig. 13.) (Rufford Coll.) 1895. Conites armatws Seward, ‘ Wealden Flora’ pt. 2, p. 222 & pl. ix. fig. 7. When the specific name armatus was given to this Wealden cone in 1895, the previous use of the designation Conites armatus by Sternberg * was unfortunately overlooked. The obscure fossil so named by Sternberg was subsequently transferred to Hquisetites priscus Gein. by Feistmantel,” in his account of the Radnitz flora. The new specific title is chosen in recognition of the valuable contributions to our knowledge of Potomac plants made by Mr. E. W. Berry. The portion of a cone shown in fig. 13 is less incomplete than the type-specimen : the cone-scales are oval or more or less poly- gonal, with a strong angular spine similar to that observed on the ? Sternberg (25) p. xxxix & pl. xlvi, fig. 1. 2 Feistmantel (75) p. 94. 104 PROF, A. C, SEWARD: CONTRIBUTION To ‘| March 1913, scales of Pinus coulteri Don and other recent species. There is, however, no evidence as to the nature of the seeds; and the taxonomic position of the species, whether a Conifer or a Cycad, is still in doubt. The close resemblance in the form of the scales to those of Androstrobus nathorsti Sew.’ is worthy of remark, although the habit of that species is a distinguishing feature. CONIFERALES. ARAUCARINE®. ARAUCARITES PIPPINGFORDENSIS (Ung.). (Fairlight Clay, Fairlight ; Dawson Coll.) 1836. ‘A Cone of an unknown Species ...... from Pippingford in Ashdown Forest’: Fitton, Trans. Geol. Soc. ser. 2, vol.iv, pt. 2, p. 181 & pl. xxu, fig. 10. 1850. Zamiostrobus pippingfordensis Unger, ‘ Gen. Spec. Plant. Foss.’ p. 300. A comparison of the well-preserved impression in the Dawson Collection with Unger’s type-specimen in the British Museum (Natural History) leads me to adopt his specific name. Mr. Car- ruthers* substituted the genus Araucarites for Zamiostrobus, in view of the very close resemblance of Unger’s species to the Jurassic A. sphwrocarpus Carr. and similar cones. This recently-acquired specimen is an impression of an almost spherical cone (6x5 cm.) consisting of woody scales with rhom- boidal distal ends, 9 mm. broad and 5 to 6 mm. deep, with a transverse ridge extending over the exposed surface immediately above a median oval scar or umbo. The Wealden cone previously described as A. (Conites) sp. is no doubt a very closely-allied, if not an identical, type.° Aravcarites sp. (PI. XII, fig. 5.) (Dawson Coll.) The cone-scale shown in Pl. XII, fig. 5, may belong to A. pip- pingfordensis, The form of the scale, which bears a single seed, is very similar to that of other Araucarian cone-scales described from American localities*; but it is futile to attempt an accurate specific identification of imperfectly-preserved specimens of this kind. - The specimen is figured, in illustration of the occurrence of an Araucarian scale rather larger than any hitherto recorded from British Wealden localities. ABIETINED. Pryires sormst Sew. (Rufford Coll.) 1895. A. C. Seward, ‘ Wealden Flora’ pt. 2, p.196 & pl. xviii, figs. 2-3; pl. xix. A specimen in the Rufford Collection (V 3695) is worthy of + Seward (95) pl. ix, fig. 1. 2 Carruthers (69) p. 3. * Seward (95) p. 191 & pl. xii, figs, 1-2. 4 Ward (99) pl. clxiii; Berry (11%) p. 399 & pl. Ixxvii, fig. 5. Vol. 69. | OUR KNOWLEDGE OF WHALDEN FLORAS, 105 mention, as illustrating more clearly than any examples hitherto described the alternation on a slender shoot of small crowded leaf- scars with more widely separated scars. This type of branch is fairly common, both in Wealden and in Jurassic floras ; and, in some cases at least, there can be no doubt as to the close affinity of such shoots to those of recent Abietinece. Pryires sp., cf. P. punxeri Carr. (Pl. XII, figs. 6 & 7.) (Fairlight Clay, Fairlight; Dawson Coll.) 1866. Pinites dunkeri Carruthers, Geol. Mag. vol. ii, p. 542. The imperfect scale shown in Pl. XII, fig. 6 is characterized by a broad and bluntly-rounded distal end, 8 mm. wide, with a terminal umbo. At the lower end is the faint impression of a seed, or probably two small contiguous seeds. In general appearance the specimen bears a close resemblance to the seminiferous scales of the Himalayan pine, Pinus excelsa Wall. At the base of the scale represented in Pl. XII, fig. 7 the presence of two seeds is clearly shown. It is impossible to speak with confidence as to the specific identification of these two scales; but a comparison with the scales of the large Wealden cone P. dunkeri Carr. leads me to suggest identity with that species. While it is hopeless to attempt a satis- factory diagnosis of the different forms of Lower Cretaceous cones, it 18S a significant fact that in the vegetation of this period the Abietinez play a prominent part. In addition to the species of Abietineous cones mentioned in the ‘ Wealden Flora,’ reference may be made to specimens described by American authors from the Shasta Formation of California and the Potomac Group as A bietites macrocarpus Font. and A. angusticarpus Font.,’ which are hardly distinguishable from Pinites dunkeri. Comparison may also be made with cones figured by Fliche from Lower Cretaceous beds in the Argonne, as, for example, P. andrwi Coem.* Some of the seed-bearing scales described by Prof. Nathorst as Pityolepis tolli® from Jurassic beds in Kotelny (New Siberian Islands) are similar to those reproduced in PJ. XII, figs. 6 & 7, but they differ in shape and are larger. Species Coniferarum incerte sedis. SPHENOLEPIDIUM KURRIANUM (Dunk.). (PI. XII, figs. 10 a & 10 5.) (Dawson Coll.) 1846. Thuites (Cupressites?) kurrianus Dunker, ‘Monographie der Nord- deutschen Wealdenbildung’ p. 20 & pl. vii, fig. 8. The small cone shown in fig. 10q@ occurs in association with slender shoots bearing spirally-disposed leaves, and agrees closely ' Fontaine (89) pl. cxxxii; Fontaine in Ward (05) pl. Ixviii, figs. 15-16, pl. exiv, fig. 10, & pl. exv, figs. 2-3. 2 Fliche (96) p. 115 &pl. x, figs. 3-4. * Nathorst (07) pl.ii, especially fig. 3. 106 PROF. A. C. SEWARD ON WEALDEN FLORAS. [ March 1913. with fertile shoots referred to Sphenolepidium kurrianum. Some of the seeds have a median distal process (fig. 104), a feature not hitherto noticed. Further information as to the structure of this common type is required before it can ‘be assigned to its position in the Coniferales: the use of such generic names as A throtaxopsis,” Taxodium, Glyptostrobus, and Widdringtonites is altogether un- justifiable. Planta incerte sedis, a. (Pl. XII, figs. 8 & 9.) (Dawson Coll.) The incomplete specimens shown in Pl. XII, figs. 8 & 9 are clearly of the same type. That represented in fig. 9 consists of a central region, with the remains of a thin torn membrane on each side characterized by numerous, spreading, vein-like impressions. In the lower part of the median region is a prominent convexity, measuring 7 x4 mm., possibly caused by a seed; beyond this the axial region is slightly depressed, and tapers gradually upwards. A similar seed-like prominence is seen in fig. 8, and the thin membrane appears to be attached along two obliquely-ascending lines, meeting in the apical region. An obvious comparison is with the cone-scales of Araucarites, of the type represented by recent species in the section Eutacta, but this resemblance may well be misleading. It is possible that these two fossils are the basal portions of petioles provided with stipular or winged appendages ; but more complete specimens are needed to establish the nature of these problematical organisms. Planta incerte sedis, 2. (Pl. XII, fig. 11.) (Dawson Coll.) This specimen consists of an approximately circular funnel-like body, 7 mm. in diameter, partly covered with a thick film of coal. The sides of the depression are longitudinally striated. The reverse (fig. 11) shows the striations radiating from the apex of the conical elevation. It is impossible to speak with confidence as to the nature of this fossil: it differs in form from Equisetaceous diaphragms, but it is similar to, though smaller than, the impressions described by Williamson : as the infundibuliform dise of Williamsonia [ Zamia]. A very obscure specimen from the Potomac Group, described as W. (?) gallinacea,' may also be compared with the fossil shown in Jel, SOUL, aie IO III. General Survey of the Wealden Floras. The following list includes both the British Wealden plants mentioned in the ‘ Wealden Flora’ and subsequent additions :— 1 For the most recent synonymy, see Berry (117) p. 432. 2 Fontaine (89) p. 239. $ Williamson (70) pl. lii, fig. 2. * Ward (05) pl. evii, fig. 4. THALLOPHYTA. ‘ Algites valdensis Sew. Algites catenelloides Sew. CHAROPHYTA. Chara knowltoni Sew. BRYOPHYTA. Marchantites zeilleri Sew. PTERIDOPHYTA. E.QUISETALES. Hquisetites lyelli Mant. Hquisetites burchardti Dunk. | Hquisetites yokoyame Sew. LYCOPODIALES. Lycopodites teilhardi, sp. nov. | Selaginellites dawsoni, sp.nov. [Planta incerte sedis, Seward (94) p. 20& pl. 1, figs. 8-9. | FILICALES. ? Hydropteridee. Sagenopteris mantelli (Dunk.). Sagenopteris acutifolia Sew. Hufilicinee. Matoninez. Matonidium goepperti (Ett.). Laccopteris dunkeri Schenk. Dipteridinez. _ Hausmannia pelletieri, sp.nov. Gleicheniacez. Gleichenites cycadina (Schenk) [= Nathorstia valdensis & Leckenbya valdensis, Seward (94) p. 145 & (95) p. 225.) Cyatheacez. Protopteris witteana Scheuk. Schizzeacee. Ruffordia gepperti (Dunk.). ? Schizeeaceze. Cladophlebis browniana (Dunk.). Tempskya schimperi Corda. Pelletieria valdensis, gen. et sp. noy. Polypodiacez. Onychiopsis mantelli (Brongn.) [including O. elongata (Gey].) Seward (94) p. 55]. Enufilicinese incerte sedis. Cladophlebis albertsii (Dunk,). Cladophlebis longipennis Sew. | Sphenopteris fontainet Sew. Sphenopteris fittoni Sew. Acrostichopteris ruffordi Sew. Teniopteris beyrichii Schenk. Teniopteris dawsoni Sew. Teilhardia valdensis, gen. et sp. Noy. ? Hufilicinee. Dichopteris delicatula, sp. nov. Dichopteris sp., cf. D.levigata (Phill.). | Weichselia mantelli (Brongn.). CYCADOPHYTA. | BENNETTITALES. Bennettites saxbyanus (Brown) Williamsonia carruthersi Sew. CYCADOPHYTA INCERTHX SEDIS. Androstrobus nathorsti Sew. Bucklandia anomala (Stokes & Webb). Fittonia ruffordi Sew. Fatesia morrisii Cary. Cycadolepis spp. (including Dory-Cycadolepis and Bury- Cycadolepis). Cycadites reemeri Schenk. Cycadites saporte Sew. Dioonitesdunkerianus (Goepp.) Dioonites brongniarti (Mant.). Nilssonia schawnburgensis (Dunk.). Anomozamites lyellianus (Dunk.). Otozamites klipsteinii(Dunk.). Otozamites gceppertianus (Dunk.). Zamites buchianus (Ett.). Zamites carruthersi Sew. Pseudoctenis eathiensis (Rich.) |?Zamites sp., Seward (95) p- 89, fig. 5]. Ctenis sp. CONIFERALES. Araucarines. Araucarites pippingfordensis (Ung.). Araucarites sp. Hlatides sternbergiana( Dunk.) [Sphenolepidium sternbergi- anum Seward (95), p. 205 }. Elatides curvifolia (Dunk.) { Pagiophyllum crassifolium Schenk, Seward (95) p. 212). Cupressinese. Thuites valdensis Sew. Abietiner. Pinites solmsi Sew. Pinites dunkeri Carr. Pinites carruthersi Gard. Pinites ruffordi Sew. Pityospermum sp. | Coniferales incerte sedis. Sphenolepidium kurrianum (Dunk.). Brachyphyllum spinosum Sew. Brachyphyllum obesum Heer. Nageiopsis sp., ct. N. hetero- phylla Font. GYMNOSPERM® INCERT® SEDIS. Conites berryi Sew. [=C. ar- matus Seward (95) p. 222). Becklesia anomala Sew. Benstedtia sp. [Seward (96) ]. Sewardia saporte (Sew.) '= Withamia saporte, Seward (95) p. 174. ] PLANT #® INCERT® SEDIS. Specimens described in the ‘Wealden Flora’ (94) p. 19 & pl. i, fig. 7, and on p. 106 of this paper. 108 PROF. A. C. SEWARD: CONTRIBUTION TO [March 1913, Notes on the List of British Wealden Plants. Chara knowltoni Sew.—Fragments of Chara preserved in the Purbeck chert-beds, near Swanage, have also been referred to this species.! Tempskya schimperi Corda.—This species, with two others, is included provisionally in the family Schizeacez, on evidence which cannot be regarded as conclusive. Ina recent account of a Russian species of Tempskya Dr. Kidston & Prof. Gwynne-Vaughan * con® tribute important information with regard to the anatomy of the stem and petiole, and discuss the affinities of the genus. The presence of a solenostele in the stem, as the authors point out, while suggesting a comparison with certain recent Schizeacez, as with some.other ferns, is not in itself a conclusive criterion as to systematic position; but the discovery by Mr. Boodle® of ridged spores embedded in the tissues of the Wealden species is noted as a point in favour of, though not demonstrating, relationship to the Schizzeacee. Dichopteris.—The position of this genus is still undecided, and, though included in the above list in the Filicales, it has not been proved a fern. Weichseia mantelli (Brongn.)..—Dr. Bommer’ has recently published an interesting preliminary note on this characteristic Wealden plant, in which he describes some imperfectly-preserved reproductive organs, originally described from isolated specimens as Conites minutus*; he also throws fresh light on the morphology of the frond, and shows that the specimens hitherto regarded as portions of bipinnate fronds are large compound pinne borne in a fan-like cluster at the expanded summit of a thick petiole, the anatomy of which is described. Dr. Bommer compares Weichselra with the Matoninex and Marattiacesw, suggesting also the possibility of a Pteridosperm alliance. Dioonites dunkerianus (Gcepp.).— Prof. Nathorst* draws attention to a certain resemblance between the epidermal structure of this species and that of Pseudocycas insignis Nath., without suggesting specific or even generic identity. Elatides.—It should be pointed out that the reference of this genus to the Araucarinee is based on the structure of some cones,” and not only on a similarity in habit of vegetative shoots. The Araucarian affinity, although very probable, cannot be regarded as definitely established. 1 Seward (98) p. 224, fig. 45, A & B. 2 Kidston & Gwynne-Vaughan (11). > Boodle (95). 4 = Weichselia reticulata (Stokes & Webb). > Bommer (10). 6 Seward (00) p. 28 & pl. iv, figs. 60-62, 64. 7 Nathorst (07°) p. 6. ° Seward (11) p. 685; Nathorst (97) p. 58. Vol. 69.] OUR KNOWLEDGE OF WEALDEN FLORAS. 109 Pinites ruffordi Sew.—For a description, with illustrations, of this species, founded on petrified wood, see Seward (96°). Nageiopsis sp.—The specimens on which Fontaine founded his species JV, heterophylla are identified by Mr. Berry ' as NV. zamioides Font., and the genus is believed by him to be closely allied to the recent Conifer Podocarpus, an opinion which still lacks the support of reproductive shoots. Benstedtia.—Dr. Marie Stopes” has recently shown that in some of the casts placed by me in this genus the wood consists of tracheids like those of certain Conifers (not Araucarian), and she suggests that Fliche’s generic name Ooniferocaulon should be sub- stituted for Benstedtia. Sewardia saporte (Sew.).—Prof. Zeiller,’ who, despite my care- less employment in the ‘ Wealden Flora’ of a generic designation (Withamia) already in existence, instituted the present genus, places this plant among the Cycads. While this may be its true position, we have as yet no means of deciding whether it is a Cycad or a Conifer. The recent monograph by Mr. Berry* and other contributors published under the auspices of the Geological Survey of Maryland renders unnecessary a comprehensive review of the Wealden floras of the world. In this exceedingly useful and important volume Mr. Berry not only describes several new types of Potomac plants, but revises the work of previous writers and deals with the geographical distribution and geological sequence of Lower Cre- taceous floras generally. The subjoined table (p. 111) is drawn up with the view of illus- trating the geographical range of some of the more widespread and better-known Wealden plants; it does not profess to show the range of plants specifically identical with the British types selected, but to express in general terms the range of species believed to be closely allied to, and in some cases specifically identical with, these types. In endeavouring to form an opinion as to the degree of re- semblance between one flora, in this case a British flora, and floras of the same or approximately the same age in other regions, the most profitable and feasible pian would seem to be to regard the plants selected for our purpose as representative types equivalent not to single species in the ordinary sense, but, as a rule, to two or more closely-allied types. A few examples may serve to explain the nature of the basis on which the table is compiled. Hquisetites lyelli is used in a comprehensive sense, as including Equisetaceous 1 Berry (107) p. 191. 2 Stopes (11). See also Seward (96); id, (03) p. 35; Knowlton (11); Stopes (112). 3 Zeiller (00) p. 282. eo Berny, (Wl). 110 PROF. A. C. SEWARD ON WEALDEN FLORAS. [March 1913, plants agreeing generally with Mantell’s type, though by no means in all cases specifically identical with the species on which the records are founded. Similarly Araucarites pippingfordensis and Pinites solmsi* represent respectively Araucarian and Abietineous plants accredited to different regions, on evidence furnished by identical or closely-allied species. In addition to the regions named at the head of the table, there are a few others from which Neocomian species have been recorded ; but the number of such specimens is small, and the floras are not sufficiently important to be included in a general summary which is admittedly incomplete. A few plants have been described by Prof. Nathorst * from Neocomian rocks in Mexico, and it is possible that a few species recorded from New Zealand ’® are members of a Wealden flora. Neocomian species have been described from South- Western China,‘ and an imperfectly-preserved specimen from Egypt is compared with |Weichselia mantelli’ The age of the Spitsbergen and King-Charles-Land plants is considered by Prof. Nathorst to be Uppermost Jurassic, the term ‘Jurassic’ being understood to include Wealden floras.’ It is generally recognized that, botanically, the limit between Jurassic and Cretaceous floras, using the terms in the ordinary strati- graphical sense, is largely conventional.’ Prof. Nathorst also assigns the plants described by him from Franz Josef Land to the upper part of the Jurassic System.” From Bornholm afew plants have recently been described? as probably Wealden in age, although the great majority of species from that island are from a Liassic or even Rheetic horizon. The material described by Neumann, Zeiller, and Salfeld from Peru, though sma!l in amount, indicates the presence of a Wealden flora. In Eastern North America *’ the Potomac Group, or at least the older plant-beds, have afforded a particularly rich harvest of Lower Cretaceous or Cretaceo-Jurassic types. On the west side are the Kootanie plants (Montana), the Shasta flora (California), the plant- beds in the Queen Charlotte Islands, and other floras described by several authors. 1 The Middle Cretaceous species Prepinus statenensis Jeffrey from Kreisch- erville, New York, is probably a closely allied type. See Hollick & Jeffrey (09) p. 19. 2 Nathorst (907). ® See Seward (94) p. xxxiil. + Yokoyama (06). ° Seward (072). 6 Nathorst (97); zd. (10) p. 369. See also Gothan (07). 7 Van den Broeck (01) p. 199. On this subject, see an important note by Mr. Lamplugh (00). 8 Nathorst (99). 3 Bartholin (10). 10 Neumann (07); Zeiller (10); Salfeld (09). 11 For references, see Berry (117): also Knowlton (10); Chamberlin & Salisbury (06) vol. iii, chap. xiv. “E} ) | ‘watussardny og jo 4iqvy oyy oAvy 04 ein iyaediaon 4 + + + 23 ere eae wnsowds unpphydiyooi.g unpphydhyovig se Liag Wor ppayvg Aq paansg uaunoods ayy, ) ar eS Fae + 3F + a gael Ons | UnUDLLInY unyprdajouaydgy pe: etl eaters 4 geet Reise ee ISULJOS SORT + | + + + 4 fos yo fiainia sap) ip SEPIA) ACHE AKO) ON COAG PYON EAC (GLO). PY) ass | ee ||, pea oe ef noe | | wee oon 5 : ; ‘ : OPP ves “oottvtyy Ur satoads uvrieonncy JO GOUIINDDO Ot} Oy J os i i SISUED LIED Ese ona "897/U02030_ ang & ATquqoad st yt! (¢) S99 4u 208801) ) “Foe sp SE + Seger eared eUIOO snupryang saz,Unge wr [9 Sy ‘ur qd (60)] prayteg Aq paoetd st Le “By ‘It qd (Z0)] 6 + + = srupigsaddab sagvucwz0qc, sruniiaddoh sapwpzoj9 sv uuvutnay Aq painsy uautoods aug) Ef att earner a + es sryupijah) SaquUnZouLowpy + + 4 4 SIsUahINguUnDyYyIS DLUWOSS)UNT “yUjasyava ff ) Sie + | + ons SrUDIMAaYUNp $a7vUooUT sopqutosat ATasopo Aaar [TT “sy ‘taxy "pd (eo) pau Ad | quosdumoyp, » dt + | + + Pe 171AZUDUL MLIASYIVA Af -20Q)UE (7) vywayo1a7H sv ouivyuog Aq paimsy uauttoads aug) oF ats ae Dyngnorjap srvagdoyarg +} +t +/+ | + + ayar.thag srvagzdowma feoae ere 4 I ae bid pad-gndowecoodda0nd moziyl sragdouaydg iteeel ence ae eS eats ar oP os 189.4aq1) seqgazydopn)O + ete Mest leet tet + SEE [bce eee ee yjaqunu sisdovyohiuc (ct lie ec eclectic er ct ane + fo je paprumorg sigapydopniyp “payeays | StS PORN RO CTE EL alls =f gales eagle ea ysaddaob nupwo fing -MOWap Wea JOU SUIT suttas oY} JO aouatmMoII0 oq} Yuq “puoaz ) Tr . hae || a a oT ie eae ee purpnahs sa7vuayara7 9 DLUUDUSNYFT V OF GUOTOG ABUL TOM JUAUISBIT B UO papuNo; st \ a | a RELI IRS UREA TT [yp sy “Axy [Td (Go) paw Ay | quo Podofqmue (¢) vruunusnozy ) | | | "6B BGG “88g “xq Td (GO) prv Ay | | | UI OUIVIWOT “VAISNTOUOD suUBATA OU xq St YOM doUAapIAa WO - Z4 + 1 + rptaddabh wiuapw0po yy (VINIOFT[LD) WOTVULIO VISVYYG 9} WAZ Poplodat St wn2p2wWoPYTL |) hart + Ijaquvw sriagdouahvg +) + + }+ 1+] + | yak) sagrgasinbor = jest lnc} MN oy les| MN a) \e/ 8) 8) 21 o lgagioe |\e@ile | A215 12 lS lSeceg aoe l4 ie) 5 | eis | Ble i eae se & | Soy : B | de pes) [iS sts | i es ze : 3 a- |So8 ise || SP o BO) U4 ae ‘SINVId NAGTIVAM HSILIag ‘SHUVNAY ss ff Ee | We ial ie =I | = here BiQe.. 10 SHdA], CHLIATAG =) oO = © for) i) hails | | 5 iS] Sts A M Fea (Fess | SSE = ® | | a S loje} | 2 ls 112 PROF, A. C. SEWARD : CONTRIBUTION TO [March 1913, A glance at the table shows that, while there is a very close similarity between the Wealden flora of England and the corre- sponding floras in Eastern and Western North America, the number of cosmopolitan types is smaller than in the case of the Middle Jurassic floras. This may be due in part to the smaller number of records of Cretaceo-Jurassic plants, as compared with the richer and more numerous collections trom Middle Jurassic strata. The contrast between Wealden and Middle Jurassic floras is com- paratively small, and it is difficult to select species which in themselves are safe criteria as to the occurrence of a Wealden, as distinct from a true Jurassic, flora. Onychiopsis mantelli, Weichselia mantelli, and a few other types may be described as useful index- plants pointing to a Wealden age; but it is, as a rule, only by the examination of a fairly large number of species that any definite pronouncement is justifiable as to the value of paleeobotanical data in regard to age-determination. It must not be forgotten that there are several Wealden species recorded trom North-Western Germany, the Arctic regions, and elsewhere, which have not as yet been discovered in the English area. The Ginkgoales are a case in point: the genera Ginkgo and Baiera, both fairly abundant in the Jurassic vegetation of East Yorkshire, have not been found in the Wealden of England. The fact that these plants existed in the Kimmeridgian Epoch in Scotland, as also in the Wealden flora of Germany, favours the view that their absence from the list of English species (p. 107) is one of the many lacunze which further search may be expected to fill. IV. Bibliography. 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African Mus. vol. iv, pt. 1. Sewarp, A.C. (07). ‘Notes on Fossil Plants from South Africa’ Geol. Mag. dec. 5, vol. iv, p. 481. Sewarp, A. C. (077). ‘Fossil Plants from Egypt’ Geol. Mag. dec. 5, vol. iv, p. 253. Srwarp, A.C. (10). ‘ Fossil Plants’ vol. ii. Cambridge. SEwarp, A.C.(11). ‘The Jurassic Flora of Sutherland’ Trans. Roy. Soc. Edin. vol. xlvii, pt. iv, p. 643. Sewarp, A.C. (12). ‘Mesozoic Plants from Afghanistan & Afghan Turkestan” Mem. Geol. Surv. India (Pal. Indica) n.s. vol. iv, Mem. 4. STERNBERG, G. (25). ‘ Versuch einer geognostisch-botanischen Darstellung der Flora der Vorwelt’ Leipzig, 1820-38. Stokes & Wess (24). ‘Descriptions of some Fossil Vegetables of the Tilgate Forest in Sussex’ (Anon.) Trans. Geol. Soc. ser. 4%, vol. i, pt. 2, p. 421. Stopes, Marte C. (11). ‘The “ Dragon Tree” of the Kentish Rag, with Remarks on the Treatment of Imperfectly Petrified Woods’ Geol. Mag. dec. 5, vol. viii, p. 55. Stopes, M. C. (112). ‘The Name of the “ Dragon Tree” ’ Geol. Mag: dec. 5, vol. viii, p. 468. Stoprs, M. C., & K. Fusir (10). ‘Studies on the Structure & Affinities of Cretaceous Plants’ Phil. Trans. Roy. Soe. ser. B, vol. cci, p. 1. Tuomas, H. Hamsuaw (11). ‘The Jurassic Flora of Kamenka’ Mém. Com. Géol- Russie, n. s. No. 71. Uneerr, F. (50). ‘Genera & Species Plantarum fossilium’ Vienna. Van DER Brokck, E.(01). ‘A proposde la Présentation par M. P. Coorrat d’une Etude Régionale sur la Limite entre le Jurassique & le Crétacique’ Bull. Soc. belge Géol. vol. xv (Proc. Verb.) p. 190. Warp, L. F. (99). ‘The Cretaceous Formation of the Black Hills, as indicated by the Fossil Plants’ 19th Ann. Rep. U.S. Geol. Surv. p. 521. Warp, L. F., with the collaboration of W. M. Fontatne, A. Breprns, & G. R. Wie- LAND (05). ‘Status of the Mesozoic Floras of the United States. 2nd Paper’ Monogr. U.S. Geol. Surv. vol. xlviu. Wretanp, G. R. (11). ‘On the Williamsonian Tribe’ Amer. Journ. Sci. ser. 4, vol. xxxui, p. 433. Wittramson, W. C. (70). ‘Contributions towards the History of Zamia gigas Lind}. & Hutt.’ Trans. Linn. Soc. vol. xxvi, p. 663. Yass, H. (05). ‘Mesozoic Plants from Korea’ Journ. Coll. Sci. Tokio, vol. xx, No. 8. Yoxoyama, M. (94). ‘ Mesozoic Plants from Kozuke, &c.’ Journ. Coll. Sci. Tokio, vol. vii, pt. 3, p. 201. Yoxoyama, M. (06). ‘Mesozoic Plants from China’ Journ. Coll. Sci. Tokio, vol: xxi,,No.9. _ ZEILLER, R. (00). ‘ Hléments de Paléobotanique’ Paris. ZEILLER, R. (06). ‘Bassin Honiller & Permien de Blanzy & du Creusot, pt. 2 Flore Fossile’ Fitudes Gites Min. France (Minist. Trav. Publ.). ZEILLER, R. (08).’ ‘Les Progrés de la Paléobotanique de l’ Ere des Gymnospermes * Progressus Rei Botanic, vol. ii, p. 171. Jena. Quart. Journ. Geot. Soc. Vor. LXIX, Pt. XI. la. ays 2b. 3} 3 ioe @ } ‘ “— Nuret i { 8b ohh. sy s eens ene hg tobi. OR IR BA, y ~ Seay - “Wein, iat Ba eed raglan : ; TA Brock, Del Bemrose, Collo., Derby. EQUISETITES, LYCOPODITES, SAGENOPTERIS, DICHOPTERIS, TEILHARDIA, AND FILIX incert. Sed. 4 Quart. Journ. Geot. Soc. Vor. LXIX, Pc. XII. 3b. } Mh epee, behets VA T.A.Brock, Del. Bemrose. Collo,, Derby CTENIS, EURY- CYCADOLEPIS, ARAUCARITES, PINITES, SPHENOLEPIDIUM, PELLETIERIA, CONITES, ETC. iy a aT al \ ba Quart. Journ. Geox. Soc. Vor. LXIX, PL. XIII. W. Tam s, Photo. Bemrose, Collo., Derby. CLADOPHLEBIS BROWNIANA (DUNK.) Quart. Journ. Geo. Soc. Vor. LXIX, PL. XIV. W. Tams, Photo. Bemrose, Colla, Derby. HAUSMANNIA; MATONIDIUM; PELLETIERIA; APHLEBIA; AND EURY- CYCADOLEPIS. Vol. 69.] OUR KNOWLEDGE OF WEALDEN FLORAS. 115 ZEILLER, R. (10). ‘Sur quelques Plantes Wealdiennes du Pérou’ C. R. Acad. Sci. : Paris, vol. cl, p. 1488. ZoBEL, — (12). ‘[Ueber das sogenannte Marsilidium Schenk ]’ Zeitschr. Deutsch. Geol. Gesellsch. vol. lxiv, Monatsber. No. 5, p. 260. HXPLANATION OF PLATES XI-XIV, [The specimens are all in the British Museum (Natural History). In cases where the drawings are larger than natural size the magnification is stated. The numerals in parentheses are the Museum Register-numbers. | Puate XI. Figs. 1a & 1b, Hquisetites lycili (Mant.). (V 12303.) 1ox8. (See p. 85.) Figs. 2a & 26. Lycopodites teithardi, sp. nov. (V 12304.) 266. (See p. 86.) Figs. 3 & 5. Sagenopteris mantelli (Dunk.). (V 12305, V 12306.) - (See p. 87.) Fig. 4. Sagenopteris acutifolia Sew. (V 2344.) (See p. 88.) Figs.6a &606. Dichopteris delicatula, sp. nov. (V 12307.) 60x3. (See p. 98.) Figs. 7 a-9 db. Ththardia valdensis, gen, et sp.nov. (V 3748.) 76,8b, & 9d, allx3. (See p. 96.) Fig. 10. Filix incerte sedis. (V 2735.) (See p. 97.) Puate XII. Figs. 1 a-2. Ctenissp. (V 2814.) 16xX2. (Seep. 101.) | Figs. 3a-4c. Eury-Cycadolepis sp. (V 12308 & V 12309.) 34 & 3cx6; 4a half of the natural size; 46 & 4ex14. (See p. 101.) Fig. 5. Araucarites sp. (V 12310.) (See p. 104.) Figs. 6 & 7. Pinites sp., cf. P. dunkeri Carr. (V 12511 & 12312.) (See p. 105.) Figs. 8 & 9. Planta incerte sedis, w. (V 12313 & 12314.) (See p. 106.) Figs. 10a & 106. Sphenolepidium kurrianum (Dunk.). (V 12315.) 100x3. (See p. 105.) Fig. 11. Planta incerte sedis, B. (V 12514.) (See p. 106.) Figs. 12a & 120. Pelletieria valdensis, gen. et sp. nov. (V 23829.) 12bx4. (See p. 91.) Fig. 13. Conites berryi, sp. nov. (V 3747.) (See p. 103.) Prare XIII. Figs. 1 & 2. Cladophlebis browniana (Dunk.). (V 12322.) (See p. 95.) Puate XIV. Figs. 1-3. Hausmannia pelletiert, sp. wov. (V 12816—-V 12318.) 1x2; 2x3. (See p. 89.) Fig. 3a. Matonidium gepperti (Ktt.). (V 12816.) (See p. 89.) Fig. 4. Aphicbia sp. (V 3714.) (See p. 98.) Fig. 5. Pelletieria valdensis; spore highly magnified. (V 2329.) (See p. 92.) Fig. 6. Bg eun aco sp.; cuticle highly magnified. (V 12319.) (See p. 103.) Discusst0n. Mr. Cuartes Dawson thanked the Author on behalf of Father Félix Pelletier and Father P. Teilhard de Chardin for his kindness _ in undertaking the determination and description of the Wealden plants collected by them from the Fairlight Clays at Hastings. 12 116 PROF. A. C. SEWARD ON WEALDEN FLorAs. _[ March 1913, For the last four years these French gentlemen had been staying at the Jesuit College at Ore, Hastings, and had devoted nearly the whole of their spare time to the collection of fessils from the Hastings and Purbeck Beds. They had displayed an immense amount of industry and perception, and had brought together a most interesting and valuable collection. A chance meeting with them by the speaker had enabled him to assist them in the determination of many of their specimens by frequent reference to the British Museum, tq which Dr. A. Smith Woodward had given every encouragement. The speaker was glad to say that, at the conclusion of their visit to England, Fathers Pelletier and Teilhard de Chardin had most generously allowed Dr. Woodward to make a selection of any specimens which he wished to have for the British Museum (Natural History). The remainder of their specimens they presented to the Hastings Museum, which contains a collection of fossil Wealden plants only second in importance to the National collection. Mr. Dawson observed as to the fossil plants now described, that it was rather remarkable to find side by side on one piece of Wealden rock remains of fossil ferns, Matonidium and Hausmannia, genera which have long ceased to exist in the Northern Hemisphere, but are very closely allied to the modern Matonia and Dipteris respectively, which now grow side by side on Mount Ophir in the Malay Peninsula. The Author had very ably dealt with these comparisons in his recent work, ‘ Links with the Past in the Plant World.’ Dr. W. F. Hume remarked that Father Teilhard de Chardin first developed his geological enthusiasm in Egypt, and congratulated British geology on his transference to England, as also on the fact that his materials had been described by Prof. Seward. The Prusipent (Dr. A. SrraHan) congratulated the Society on having heard a brilliant exposition of a difficult and highly technical subject. Bearing in mind the -stratigraphical relationships of the Wealden, he was relieved to hear that there were some plants which served to distinguish that formation from the Jurassic. The AurHor expressed gratitude to the Fellows for their cordial reception of his paper; he thanked Mr. Dawson for the very great assistance which he had rendered both personally and through Father Pelletier and Father Teilhard de Chardin towards the investigation of the Wealden Flora. He adduced some additional statements in support of the view, with which he agreed, that in many instances Southern countries are the refuges of Mesozoic types which were gradually driven across the Equator. Vol. 69.] DISCOVERY OF A PALMOLITHIC HUMAN SKULL IN sussex. 117 8, On the Discovury of a Panmoriratc Human Sxuut and MAnvIBLe in @ PLINT-BEARING GRAVEL OVERLYING the WEALDEN (Hastines Berns) at Pirrpown, Fiercuine (Sussex). By Cuartus Dawson, F.S.A., F.G.S., and ArrHur Suira Woopwarp, LL.D., F.R.S., See.G.8. With an Appenprix by Prof. Grarron Eruior Surra, M.A., M.D., F.R.S.. (Read December 18th, 1912.) I. Grotoey anp Frint-Imptements. [C. D.] [Prares XV-XVII.]| SEVERAL years ago I was walking along a farm-road close to Piltdown Common, Fletching (Sussex), when I noticed that the road had been mended with some peculiar brown flints not usual in the district. On enquiry I was astonished to learn that they were dug from a gravel-bed on the farm, and shortly afterwards I visited the place, where two labourers were at work digging the gravel for small repairs to the roads. As this excavation was situated about 4 miles north of the limit where the occurrence of flints overlying the Wealden strata is resorded, I was much interested, and made a close examination of the bed. I asked the workmen if they had found bones or other fossils there. As they did not appear to have noticed anything of the sort, I urged them to preserve anything that they might find. Upon one of my sub- sequent visits to the pit, one of the men handed to me a small portion of an unusually thick human parietal bone. I immediately made a search, but could find nothing more, nor had the men noticed anything else. The bed is full of tabular pieces of iron- stone closely resembling this piece of skull in colour and thickness ; and, although I made many subsequent searches, I could not hear of any further find nor discover anything—in fact, the bed seemed to be quite unfossiliferous. It was not until some years later, in the autumn of 1911, on a visit to the spot, that I picked up, among the rain-washed spoil- heaps of the gravel-pit, another and larger piece belonging to the frontal region of the same skull, including a portion of the left superciliary ridge. As I had examined a cast of the Heidelberg jaw, it occurred to me that the proportions of this skull were similar to those of that specimen. I accordingly took it to Dr. A. Smith Woodward at the British Museum (Natural History) for comparison and determination. He was immediately impressed with the importance of the discovery, and we decided to employ labour and to make a systematic search among the spoil-heaps and gravel, as soon as the floods had abated; for the gravel-pit is more or less under water during five or six months of the year. We accordingly gave up as much time as we could spare since last spring (1912), and completely turned over and sifted what spoil- 118 MR. C. DAWSON ON THE DISCOVERY OF [March 1913, material remained; we also dug up and sifted such portions of the gravel as had been left undisturbed by the workmen.” - Fig. 1.—Plan of the basin of the Sussex Ouse, showing the distribution of tron-stained flints and flint-bearing gravels. coe :| Region of occasional [****! |ron-stained Flints. ty Gravel-Beds } paar known by Section. é ya) Ww Bealeeie ) ci ¥ Chelwood Wiveisiieldg ¢ 2s s52 0602 ie. : !qUckfield 7 SEGicham Hill v Sa ie eer teenies BE Bie S ah) 5 KI ° imac SS a ° dO cue SS ieee ene 5 Ml 33. /ifEBarcoimbe « SG eae FLower Rise f onan : uO) Kingston + @ ine ee Scale of 4 Miles For many years the harder layers of this gravel-bed have been intermittently worked for farm-road material, as shown by old excavations which are now overgrown, but are traceable over the adjoining fields; and there is known to exist a gravel-bed of appreciable thickness extending over several neighbouring acres. Where the beds have been naturally denuded, a large number of 1 These excavations were undertaken with the kind consent of the Lord of the Manor, Mr. G. M. Maryon-Wilson, and of Mr. Robert Kenward, tenant of the farm, to whom the Authors wish to record their grateful acknowledgments. Vol. 69. ] A PALA:OLITHIC HUMAN SKULL IN SUSSEX. 119 the brown and red flints and the ironstone gravel are to be seen ‘overlying the plough-lands in all directions. At Piltdown the gravel-bed occurs beneath a few inches of the -surface-soil, and varies in thickness from 3 to 5 feet ; it is deposited upon an uneven bottom, consisting of hard yellow sandstone of the Tunbridge Wells Sands (Hastings Beds). It is composed for the - most part of dark-brown Wealden ironstone pebbles, but is mixed, to the extent of about a sixth of the mass, with angular brown flints, a large proportion of which are tabular in form.' Occasional cherts and quartzite pebbles also occur, but there are no recognizable Eocene pebbles.2 The flints vary from 6 or 7 inches in length by 3 or 4 inches in width, down to a very fine gravel or sand. Portions of the bed are rather finely stratified, and the materials are usually cemented together by iron oxide, so that a pick is often needed to dislodge portions—more especially at one particular horizon near the base. It is in this last-mentioned stratum tbat all the fossil bones and teeth discovered in situ by us have occurred. The stratum is easily distinguished in the appended photograph (Pl. XV) by being of the darkest shade and just above the bed-rock. The gravel is situated on a well-defined plateau of large area, lying above the 100-foot contour-line, averaging about 120 feet at Piltdown, and lies about 80 feet above the level of the main stream of the Ouse. ‘The river has eut through the plateau, both with its main stream and its principal branch, which is called the Uckfield River. Speaking generally, the remains of this plateau, of which that at Piltdown is merely a part, can in places be traced along a line drawn through Lindfield, Sheffield Park, Buckham Hill, Uckfield, and Little Horsted and southwards, broadening outwards towards the Chalk Escarpment. In fact, the whole country lying between the base of the Wealden Anticline and the Chalk Escarpment presents the appearance of one large low plateau or former base- level plane dissected by the Ouse and its tributary streams. Remnants of the flint-gravels and drifts constantly occur above the 100-foot contour-line, and upon the slopes, down which they are trailing towards the river and streams. These flint-bearing gravels and drifts have not been mapped or otherwise recorded before in the Ouse Valley, north of the boundary between the Wealden Clay and the Hastings Beds, which runs immediately south of Isfield. Up to the latter point they are 1 There is a tendency among these tabular flints to weather into a prismatic or polyhedral form. One specimen shows a column 2 inches in length. The prismatic structure is well shown in figs. 2,6, 7, & 9 of Pl. XVII. Most of the nodular flints, formerly existing, appear to have disintegrated. 2 Dr. J, V. Elsden writes that Tertiary pebbles are found in the Ouse gravels on the south near Lewes. Eocene pebbles occur in a thin bed east of the Race Stand, on the hill above Lewes; and a similar band is to be seen about 15 feet down the cliff, near the Coastguard Station at Newhaven. See Q.J.G.S. vol. xliii (1887) pp. 646-47. rammatic section of the Weald, showing the low plateau on the south capped by flint-bearing gravels. 1ag ge, 2.—D i it POY 4s9I0.4 “Y APMp2TA Scale of 4 Miles 800 Feet Vertical. aspliquepy “a vepaA Level Bios ale preysdiury ITH weypo19 poompeyy HIE PIOWJOUS UMOPY Td IBA 9SuE Areynqiiy esuoO Areynqizy eso asug ‘aquioj1eg Ayo s Aet12uS ( + Axeqnqi1y asno ‘ TOARyMeN \, E==] Distribution of Flint on the dissected Plateau. [The thickness of the gravels is much exaggerated in the above section. | common, and they have been described by Mantell,' Top- ley,” and Dr. Elsden*®; but both Topley and _ those who have followed him use almost the same words, namely, that ‘on entering the Hastings Beds country, flints no longer occur either on the surface, or in the river-grayel,’# However, in the Tunbridge Wells Sands( Hastings Beds), out of a thousand fields of which I have a record, that have all been thrice tested by means of boreholes to the depth of 3 feet, fifty fields or more furnish abundant evidence of the presence of these brown and red flints. They are present over the Wadhurst Clay between Is- field and Buckham Hill, but the boundary of this stratum is faulted. I have only found them to occur as small | fragments, and seldom on the older Wealden Beds of the higher levels within the Ouse watershed. The field-borings go to show that in the greater part of the area over which the flint is distributed, the gravel seldom occurs within 3 feet of the surface in beds of appreciable thickness; but trial-borings along the slopes reveal considerable deposits of gravel, containing small 1 «Geology of the South-East of England ’ 1833, p. 28. 2 «Geology of the Weald’ Mem. Geol. Surv. 1875, pp. 202, 273, 287-88, 292. 3Q.J.G.8. vol. xliii (1887) p: wae 4 See also A. J. Jukes-Browne, ‘Building of the British Isles” 3rd ed. (1911) p. 426; and A.C. Ramsay, ‘ Physical Geology, &e.” 5th ed. (1878) p. 344. Vol. 69.] DISCOVERY OF A PALMOLITHIC HUMAN SKULL IN sussex. 121 fragments of iron-stained flint, 6 feet and more beneath the surface. Considering the amount of material excavated and sifted by us, the specimens discovered were numerically small and localized. * Apparently the whole or greater portion of the human skull had been shattered by the workmen, who had thrown away the pieces unnoticed. Of these we recovered, from the spoil-heaps, as many fragments as possible. In a somewhat deeper depression of the undisturbed gravel I found the right half of a human mandible. So far as I could judge, guiding myself by the position of a tree 3 or 4 yards away, the spot was identical with that upon which the men were at work when the first portion of the cranium was found several years ago. Dr. Woodward also dug up a small portion of the occipital bone of the skull from within a yard of the point where the jaw was discovered, and at precisely the same level. The jaw appeared to have been broken at the symphysis and abraded, perhaps when it lay fixed in the gravel, and before its complete deposition. The fragments of cranium show little or no sign of rolling or other abrasion, save an incision at the back of the parietal, probably caused by a workman’s pick. A small fragment of the skull has been weighed and tested by Mr. 8. A. Woodhead, M.Sce., F.1.C., Public Analyst for East Sussex & Hove, and Agricultural Analyst for Hast Sussex. He reports that the specific gravity of the bone (powdered) is 2°115 (water at 5° C. as standard). No gelatine or organic matter is present. ‘There is a large proportion of phosphates (originally present in the bone) and a considerable proportion of iron. Silica is absent. Besides the human remains, we found two small broken pieces of a molar tooth of a rather early Pliocene type of elephant,’ also a much-rolled cusp of a molar of Mastodon, portions of two teeth of Hippopotamus, and two molar teeth of a Pleistocene beaver. In the adjacent field to the west, on the surface close to the hedge dividing it from the gravel-bed, we found portions of a red deer’s antler and the tooth of a Pleistocene horse. These may have been thrown away by the workmen, or may have been turned up by a plough which traversed the upper strata of the continuation of this gravel-bed. Among the fragments of bone found in the spoil-heaps occurred part of a deer’s metatarsal, split longitudinally. This bone bears upon its surface certain small cuts and scratches, which appear to have been made by man. All the specimens are highly mineralized with iron oxide. 1 Tt is stated by R. A. C. Godwin-Austen (Q. J. G. S. vol. vii, 1851, p. 288) and E. Dixon (‘Geology of Sussex’ 2nd ed. 1878, p. 110, n.) that remains of ‘the large mammalia,’ including teeth of elephants, were found in the gravels at Barcombe, 6 or 7 miles south of Piltdown. It is not known to what genera or species these belonged; but, as they are referred to as ‘the Asiatic Elephant,’ they were probably the true form of Elephas and not Mastodon, though it is possibfe that some may have belonged to the species akin to i. meridionalis. Specimens from this bed are not known to have been preserved, but they probably belonged to the Pleistocene age. A 122 MR, C. DAWSON ON THE DISCOVERY OF [March 1913, Flint-Implements. The brown flints appear to be in every way similar to the plateau flints of Ightham (Kent), and generally to those of the High-Plateau gravels of the North and South Downs. ‘There is the same appearance of tabular and prismatic structure, ‘ frost fractures,’ thick iron-stained patina, and often the same tendency to assume the well-known ‘ Eolithic’ forms (Pl. XVII). There also occur more occasionally certain brilliantly-coloured iron-red flints, presumably more highly oxidized than the prevailing flints, which are of a brown colour. Among the flints we found several undoubted flint-implements,! besides numerous ‘ Eoliths.’ The workmanship of the former (Pl. XVI) is similar to that of the ‘Chellean or pre-Chellean stage”; but in the majority of the Piltdown specimens the work appears chiefly on one face of the implements. They have been very slightly rolled or worn, and, although iron- stained, their patina is not so strong and thick as that of the other flints in the bed. Their form is thick, and the flaking is broad and sparing, the original ‘ bark,’ or surface, of the flint frequently remaining at the grasp, the whole implement thus having a very rude and massive form. Some of them were found on the surface of a ploughed field adjacent to the gravel-bed, which is also strewn with brown and red flints; but, on the surface of the neighbouring plough-lands there occur, in places, flint-implements of various ages, all more or less stained with the iron which abounds in this part of the Weald. In our plates we have confined ourselves to the representation of flints found in the gravel-pit at Piltdown. As to the ‘ Koliths, * it is necessary to speak of them with due reserve and caution. ‘The commonest types belong to the ‘ borer’ and ‘hollow-scraper’ forms. They occur both in the gravel-bed and on the surface of the plough-lands, and are found in both a rolled and an unrolled (or very slightly rolled) condition. Pl. XVII ! Father P. Teilhard, 8.J., who accompanied us on one occasion, discovered one of the implements (Pl. XVI, fig. 2) im situ in the middle stratum of the gravel-bed, also a portion of the tooth of a Pliocene elephant (Pl. XXI, fig. 2) from the lowest bed. 2 Implements of this stage are difficult to classify with certainty, owing to the rudeness of their workmanship. he Piltdown specimens may be com- pared with an example from Chelles, figured in Piette’s ‘ L’Art pendant I Age du Renne’ p. 36. They resemble certain rude implements occasionally found on the surface of the Chalk Downs near Lewes, which are not iron-stained. 3 The flints, which so nearly resemble those of the plateau gravels of the North Downs, occur sporadically over the South Downs and over many of the older rocks of the Weald. ‘They have lately been discovered im the fields close to the signal-station at Fairlight Down on the summit of the Wealden Anticline (base of the Ashdown Beds and top of the Fairlight Clay) by Mr. W. Ruskin Butterfield, of the Hastings Museum. ‘hey occur in the surface-deposits only, mingled with Neolithic implements and certain iron- stained implements which Mr. Reginald Smith, H.S.A., identifies with the early cave types. The last-named are not rolled. Mr. Lewis Abbott, F.G.S., has given considerable attention to this subject, and possesses a large series of implements which we nay hope will some day be described in detail. ~ fain ["poureyqo a10M OTGIPULUT PUB T[NYS oy} YOIYM WOIF 4VY} ST UOTJOES 94 WI YooI-poq oy uo Surysox WInzeIYS JSoyIep oy, | *XHSS09 ‘ONIHOLETY ‘NMOGLIIG LV ‘(SCHq SONLISV]]) SANVG STTOA\ TOCIVANODT, AMG ONIANTUAAO CHE-THA VD ONTUVAE- INIT ‘ * se : . : . : ‘oyoyd Aqstaq * £ 7: . Pi RE ed A go > me) oO Oo es Quart. Journ. Geot, Soc. Vor. LXIX, Pt. XVI- G.M. Woodward, del. Bemrose, Collo,, Derby. PALZOLITHS from Piltdown (Sussex). Quart. Journ. Geor. Soc. Vor. LXIX, Pu.XVIl. G M. Woodward, del Bemrese, Collo, Derby. “EOLITHS” from Piltdown (Sussex). Vol. 69.] A PALMOLITHIC HUMAN SKULL IN SUSSEX. 123 illustrates both of these classes of ‘ Eoliths.’ Whether natural or artificial, the fractures appear to have been largely governed by the prismatic structure of the flint. Both the rolled and the unrolled ‘oliths’ are deeply stained and patinated, but the former to a much greater extent than the latter. Conclusions. In conclusion, we may briefly consider the age of the human skull and mandible. ‘It is clear that this stratified gravel at Piltdown is of Pleistocene age, but that it: contains, in its lowest stratum, animal remains derived from some destroyed Pliocene deposit probably situated not far away, and consisting of worn and broken fragments. These were mixed with fragments of early Pleistocene mammalia in a better state of preservation, and both forms were associated with the human skull and mandible, which show no more wear and tear than they might have received im situ. Associated with these animal remains are ‘ Koliths,’ both in a rolled and an unrolled condition; the former are doubtless derived from an older drift, and the latter in their present form are of the age of the existing deposit. In the same bed, in only a very slightly higher stratum, occurred a flint-implement (Pl. XVI, fig. 2), the workmanship of which resembles that of implements found at Chelles; and among the spoil-heaps were found others of a similar, though perhaps earlier, stage. From these facts it appears probable that the skull and mandible cannot safely be described as being of earlier date than the first half of the Pleistocene Epoch. The individual probably lived during a warm eycle in that age. EHXPLANATION OF PLATES XV-XVII. Puate XV. Flint-bearing gravel-bed overlying the Tunbridge Wells Sands (Hastings Beds) at Piltdown, Fletching, Sussex. The darkest stratum resting on the bed-rock in the section is that from which the skull and mandible were obtained. Prats XVI. Fig. 1. Palxolithic implement, well worked on one face (1); a simple flake on the other face (1 @); twisted in edge-view (1 0); and thickest at the broader end (1c). Natural size. . Palxolithic implement, worked on one face (2); simply flaked on the other face (2a); seen in edge-view (20) to be relatively thick at the broader end, with remains of the flint-nodule from which it was made. Natural size. 3. Palxolithic implement, showing much of the outer surface of the original flint-nodule on its well-flaked face (5); simply flaked on the other face (8a); and very unsymmetrical in basal view (3 4). Half of the natural size. i) [All the above implements are iron-stained. | 124 DR, A. SMITH WOODWARD: DESCRIPTION oF [March 1913, Priate XVII. Wigs. 1-3. ‘Eoliths’ of the bow-shaped and double-edged scraper type. (Figs. 1 & 3 are rolled. fig. 2 is unrolled.) 4 & 5, Similar ‘ Koliths’ (unrolled) from Fairlight, near Hastings. 6&7. ‘Koliths’ of the drill or borer type. (Fig. 6 is rolled, fig. 7 is. unrolled.) 8-10. ‘ Eoliths’ of the crescent-shaped scraper type. (Figs. 8 & 9 are rolled, fig. 10 is unrolled.) Fig. 11. ‘ Holith’ (rolled), showing considerable chipping around its point. [All the figures are of the natural size; and all the flints which they represent are deeply stained with iron. | lJ. Desorrerion oF tHE Human Skutt and MANDIBLE AND THE AssoctatEep MamMarian Remains. [A. 8. W.] [Purares XVITI-XXT_] The Human Skuli and Mandible. THE human remains comprise the greater part of a braiti-case and one ramus of the mandible, with lower molars 1 and 2. All the bones are normal, with no traces of disease, and they have not been distorted during mineralization. Of the brain-case there are four pieces (reconstructed from nine fragments) sufficiently well preserved to exhibit the shape and natural relations of the frontal, parietal, occipital, and temporal bones, and to justify the reconstruction of some other elements by inference. These bones are particularly noteworthy for their thickness, and for the depth of the branching grooves which are impressed on their cerebral face by the meningeal vessels. The thickening is due to the great development of the finely cancellatea diploe, the outer and inner tables of the bone being everywhere comparatively thin. The thickest point is at the internal occipital protuberance, where the measurement is 20 millimetres. A thickness of 11 or 12 mm. is attained at the postero-lateral angle of the left parietal and at the horizontal ridges of the occipital; while a thickness of 10 mm. is observable along the greater part of the fractures of the parietals and frontals. Compared with the corresponding portion on the opposite side, the postero-lateral region of the right parietal is rather thin, its thickness at the lambdoid suture being 8 to9 mm. It is interesting to add that the average thickness of modern European skulls varies between 5 and 6mm.; while that of the Australian skulls! and of the Mousterian skull from La Chapelle-aux-Saints (France) * is from 6 to 8 mm. 1 W. J. Sollas, Phil. Trans. Roy. Soe. vol. excix B (1908) p. 319. 2 M. Boule, ‘L’ Homme Fossile de La Chapelle-aux-Saints’ Ann. Paléont. vol. vi (1911) p. 20. Vol. 69.] THE HUMAN SKULL, BIC. FROM PILTDOWN. 25 The largest continuous portion of the brain-case comprises the left side of the frontal and parietal regions, extending upwards just over the middle line both in the hinder part of the frontal and near the lambdoid suture of the parietal. The position of the middle line is indicated by the impression of the longitudinal sinus on the cerebral face of the bone at both these points, and by a slight longitudinal ridge along the outer face at the hinder end of the parietal region. The left temporal bone is nearly com- plete and beautifully preserved, lacking only the upper portion of the squamous wing. At one point it articulates perfectly with the squamous suture of the parietal, and the impressions of the meningeal vessels of the parietal are directly continued on its cerebral face, so that this bone can be assigned to its true position. The left side of the brain-case thus formed has no point of contact with the other two pieces of bone; but one of these is the greater part of the right parietal, extending from the lambdoid suture behind to the anterior end of the squamous suture in front, and so completely symmetrical with the left parietal that its exact position can be determined by measurement. The fourth piece of the brain-case is the middle region of the occipital bone, with a trace of the border of the foramen magnum below and a short extension as far as the lambdoid suture in one part of the right side above. The occipital and the right parietal thus come into direct contact for an extent of about 20 mm. The greater portion of the brain-case may, therefore, be reconstructed without any hypothetical restoration: the only serious deficiency being the middle portion of the frontal region above the supraorbital ridge. Such a reconstruction, with a justifiable amount of modelling, has been skilfully made by Mr. Frank O. Barlow in the Paleontological Laboratory of the British Museum, and this is shown from four aspects, with a longitudinal median section, in Pl. XVIII, figs. 1-4, and text-fig. 3 (p. 126). The actual pieces of bone are indicated by a dark tint, and the modelled portions by a lighter tint, while the hypothetical part is white. As seen from above (norma verticalis, Pl. XVIII, fig. 1), the cranium is very wide posteriorly, measuring 150 mm. across its widest part just behind the malar arch, and tapering forwards to a slight, constriction behind the supraorbital ridge, where its width is 112mm. ‘The total length from the middle of the supraorbital ridge (glabella} to the external occipital protuberance (inion) is a little uncertain, owing to the hypothetical restoration of the middle ot the frontals, but it measures probably 190 mm. The cephalic index may, therefore, be regarded as 78 or 79. Owing to the constriction of the frontal region, the malar arch is visible from above. In anterior view (norma facialis, Pl. XVIII, fig. 2), the relative narrowness of the frontal region is well shown, and the roof is seen to rise to the vertex at the widest part of the skull. In side view (norma lateralis, Pl. XVIII, fig. 3), this upward slope is still better seen, and the steeply-curved frontal contour is especially 126 DR. A. SMITH WOODWARD: DESCRIPTION oF [ March 1913, noteworthy. The external occipital protuberance (inion) seems to form the hindmost point of the cranium, though the portion of the occipital immediately above it is in an almost vertical plane. : In back view (norma occipitalis, P]. XVIII, fig. 4), the contour of the skull is very remarkable. It is relatively low and wide, and gently arched above, with the sides flattened in their upper half, and the mastoid region either vertical or slightly inclined inwards. Fig. 3.—Sagittal section of the Piltdown skull (black) superposed on that of a skull from Lewes Levels (dotted), half of the natural size. K=inion of the Piltdown skull; H=inion of the Lewes skull. The capacity of the brain-case camnot, of course, be exactly determined; but measurements both by millet-seed and by water show that it must bave been at least 1070 c.c., while a con- sideration of the missing parts suggests that it may have been a little more. It therefore agrees closely with the capacity of the brain-case of the Gibraltar skull, as determined by Prof. Keith, and equals that of some of the lowest skulls of the existing Australians. It is much below that of the Mousterian skulls from Spy? and 1 A. Keith, ‘ Ancient Types of Man’ 1911, p. 125. 2 Id. ibid. p. 112. Vol. 69. | THE HUMAN SKULL, BIC. FROM PILTDOWN. 127 La Chapelle-aux-Saints,! which have a brain-case larger than that of the average modern civilized man. The principal characters of the brain, so far as they can be observed in a cast of the cranial cavity, are described in an. appendix to this paper by Prof. G. Elliot Smith (see p. 145). A detailed examination of the several bones of the skull is interesting, as proving the typically human character of nearly all the features that they exhibit. The only noteworthy reminiscences of the ape are met with in the upward extension of the temporal fossze, and in the low and broad shape of the occipital region, The frontal region (Pl. XIX, figs. 1, 1a, & 16) is complete on the left side and in its upper middle portion, showing that the frontal eminence is regularly and steeply rounded, and separated from the temporal fossa by a sharp ridge, which extends upwards as far as the coronal suture. ‘his ridge (¢.) approaches nearest to its fellow of the opposite side at its upper end, where it is continued by the curved groove on the parietal, which trends still farther towards the middle line. At its lower end the ridge passes out- wards on to the external angular process (¢.a.p.), which is short and directly continuous with the slope of the frontal eminence, not separated from this by any depression, ‘The facette for the malar bone (m.f.) is well preserved; part of the smooth concave roof of the orbit is seen (fig. 16, orb.); and the sharp supraorbital border is but shghtly abraded. It is, therefore, clear that there- cannot have been any prominent or thickened supraorbital ridge,. and the missing region above the glabella may be restored on the plan of an ordinary modern human skull, The median frontal (metopic) suture is completely obliterated, so far as the bone is preserved above; but a fractured surface shows that the short fronto-alisphenoid suture (s.f.) was only closed in its deeper half, while the coronal suture is still just visible on the wall of the temporal fossa and is conspicuous on the cranial roof. The coronal suture (cor.) is remarkably complicated, and its tortuous folds are seen to occupy a transversely-elongated shallow depression immedi- ately above the limit of the temporal fossa. The total length of the frontal region along the metopic line, from the glabella to the- middle of the coronal suture (bregma), must have been from 120 to 130 mm.; while its maximum width at the external angular processes is 125 mm. Immediately behind the middle of the coronal suture the parietal region is distinctly flattened; but as it expands backwards the roof soon rises to the broad rounded vertex already mentioned, and there is a faint trace of a longitudinal median ridge near the hinder (lambdoid) border of the bone. The parietal boss or eminence is conspicuous on each side above the hinder end of the squamous suture; and this boss forms the apex of a large flattenedi triangular area, of which the base-line is at the lambdoid suture. The flattening just mentioned is of the same shape on each, 1M. Boule, L’Anthropologie vol. xx (1909) p. 264,’ 128 DR. A. SMITH WOODWARD: DESCRIPTION oF [March 1913, side, and the conspicuous lines marking the upper boundaries of the temporal fossz are also clearly symmetrical with reference to the long axis of the skull. The upper line, indicating the upper limit of the temporal fascia or aponeurosis, curves upwards at one point to a distance of 36 mm. from the middle line of the cranial roof; while the lower line, which marks the border of the temporal muscle itself, rises to a maximum height of 32 mm. above the summit of the squamous suture, and curves downwards behind along the antero-inferior edge of the parietal flattening already described. The median parietal (sagittal) suture is com- pletely obliterated ; but the lambdoid suture is open, and its outer lateral portion is shown to have been deeply serrated or complicated. The mastoid and squamous suture is open throughout its length, and the squamous portion is as well arched asin a typical modern human skull. The antero-inferior angle of the bone seems to have been almost excluded from articulation with the alisphenoid. The cerebral face, though deeply impressed with the grooves for the meningeal vessels, bears no distinct marks of the: Pacchionian bodies. The length of the parietal region along the line of the sagittal suture is 120 mm.: while the total length of its border at the lambdoid suture is about 210 mm. The occipital bone (Pl. XX, figs. 1, 1 a, & 14) is remarkable, both for its great width and for the relatively large extent and flatness of its smooth upper squamous portion. ' The depth of this upper portion, from the lambda to the external occipital protuberance, is 55 mm.; while the total length of the curve from the lambda to the middle of the hinder border of the foramen magnum (opisthion, f.mag.), 18 only 110 mm. The external occipital protuberance (é.9.p.) 18 distinctly marked, about twice as wide as deep; while the ridges of the superior (w.c./.) and inferior (/.¢./.) curved lines, the median occipital crest (¢.0.c.), and the other usual irregularities for muscle-attachments are also conspicuous. Above the occipital protuberance may be. seen faintly the linea suprema (/.s.). The cerebral face of the bone (fig. 1a) is interesting as showing the unsymmetrical character of the cerebellum—a condition common in modern man of both low and high degree. The grooved horizontal ridge (s?.) on the right side of the vertical median ridge is com- pletely above that on the left side, so that the upper surface of the tentorium over the cerebellum (cb.) on this side would be about 15 mm. above that on the left side. It is also important to observe that the external occipital protuberance is below the upper limit of the tentorium, as in modern man: not raised above it, as in the skull of Mousterian man. The left temporal bone is excellently preserved, lacking only some of the upper part of the squamous wing (Pl. XIX, figs. 2, 2a, 26, &2c). It is typically human in every detail, and corresponds more closely with the same bone in a comparatively modern human skull from an alluvial deposit near Lewes (Brit. Mus. 7571), than with that in the skull of an existing Melanesian from the Vol. 69.] THE HUMAN SKULL, ETC. FROM PILTDOWN. 129 Chatham Islands (Brit. Mus. 91.1.20.1). The mastoid portion has no conspicuous extension on the occipital plane, and though its process (mast.) is rather small, this is of the characteristic shape and relations, with a deep impression on its inner side for the origin of ithe digastric muscle. The supramastoid ridge on the outer face behind the malar arch is an irregularly-rounded boss. The malar arch (mal.) arisés in the usual form from the squamous part of the bone, and the glenoid cavity (g/.) is as deep as the deepest observable in modern man, with a transversely-extended hollow at the bottom slightly overhung by the anterior ginglymoid surface. There is no ‘ spina glenoidalis,’ such as is described by Prof. Boule am the Mousterian skull from La Chapelle-aux-Saints.’ A distinct though small postarticular process (p.a.p.) occurs, separating the upper part of the tympanic from the glenoid cavity; and the long axis of the ovoid opening of the external auditory meatus (¢.a.m.) is inclined downwards and backwards asin modern man, not forwards as in the Mousterian man from La Chapelle-aux-Saints.* The base of the styloid process (st.) proves it to have been very small. The petrous portion of the bone exhibits all its characteristic features, with no peculiarity worthy of remark ; and the cerebral face oi the mastoid bears the usual broad deep groove for the lateral sinus (sz.). ‘The maximum horizontal extent of the temporal bone is 95 mm., and the greatest depth of its squamous wing above the auditory meatus is 57 mm.; while its maximum thickness -at the parieto-mastoid suture is no less than 14 mm. The various measurements of the parts of the skull already given, and some others that are also of impertance, may be conveniently tabulated as below (p. 130), for comparison with the corresponding measurements of the skulls from Gibraltar and La Chapelle-aux- Saints. The right mandibular ramus (Pl. XX, figs. 2, 2a, 26, & 2c) is in the same mineralized condition as the skull, and corresponds sufficiently well in size to be referred to the same specimen without any hesitation. It lacks the articular condyle and the upper part of the bone in advance of the molars; but it is otherwise well preserved, and still exhibits the first two molars in their sockets. Its outer face is sufficiently disintegrated to show the direction of the con- stituent fibres of the bony tissue. The ascending portion, as in the mandibles from Heidelberg and La Chapelle-aux-Saints, is relativeiy broad, its width just below the sigmoid notch being 45 mm.; while its depth at the coronoid process (cor.) is about 7) mm. As in the Same jaws, its hinder margin makes an angle of 110° with the inferior margin, its sigmoid notch is comparatively shallow, and the neck of its articular condyle (cd.) must have been short. The bone itself is thin, and its outer face is deeply impressed with irregular hollows for 1 Ann. de Paléont. vol. vi (1911) p. 58. 2 Ibid. pp. 44, 54. Q.5.G.8. No. 2738. — K SKULL. = = See = Ki ~ Suet = Ss See = = z xy | & Ai 5 mn Oe aanh toe Maximum length...............| 190 190 1997 208 200 198 190 Maximum width ............... 150 144° 147 156 140 150 126 Width at supraorbital ridge.) 125 |... 122 122 114 117 107 Width at constriction behind | the supraorbital ridge ...... 2 ela O2 107 109 104. 106 92 Height, basion to vertex....... 180 |... a ee ee a 124 Do. basion to bregma ...| 130 ae SMe Lo eiliail Le aoe 125 Do. opisthion to vertex .| 130 es Do. opisthion to bregma.| 148 | | 149 Do. vertex to glabella- | inion line ............ 90 — SO. ie meee 81 87 85°5 Do. bregmatothesame.| 84 | — 765 — 69 69°7 70 Do. vertex to glabella- | | lambda line ......... a 55? Big Foliage 51 58 56 Horizontal circumference (by | | glabella and inion) ......... 540 | — 590 600 | 580 540 518 Z Cephalic index ..................{780r79| 802 TBO We eA70 74°80} 6604 76" Bregmatic angle ...............) 50° Bae? AAC) 55° 46° 47° 48°30° Cranial capacity . .| 1070 c.c. | 1080 c.c. | 1230 c.c. 1626 c.c. 1500 c.c.| 1650 ¢.c. | 1190 c.c. Total length of sagittal et curve|350t0360, — Sa helen OO il even oa 370: Length of fr ontal eienie) | curve. : ..../120t0130, = — 133 |} #121 105 120? 1297-4 }tdo Do. of parietal curve...... 120 — Vals) 7 | aA 118 114 117 150: Do. of occipital curve ...| 110 — — 115 122 — Es 110 Do. fromlambdatoinion| 55 — 51 aoe 59 59 chs 5d Do. from inion to opis- May) VE open ecoceacesade 50 ie a: Sas Fees os 8S ce ze 49 Nearest approach of temporal | fascia to mid-line ............ 36 = hs 65 == 60 29 52 Nearest approach of temporal muscle to mid-line............ 46 = fae es aes saz 38 5 Depth of temporal muscle above squamous suture ... 32 = we 35 35 v6 51 45 Maximum depth of squamous| wing aboveauditory meatus} 57 a as ee Oo ae ae 39 48: | | MANDIBLE. Piltdown. | Heidelberg. | Spy I. Eis Height of coronoid ............ 70 663 60? 60' Width of ascending 1 ramus just below sigmoid 1 notch |- 45 60 — 45? Dep tliat Ani eseseeee ets 27 31°8 33 3h? Do. atsymphysis ......... = 35 38 37 Thickness at m.2............... 15 20 14 16 Do. ~— at sy ae. Sree as 175 15 16: Length of m.1.. Leas 115 116 10 — Breadth of m1 .............. 9°5 M2 a7 | 10° — Weneth of m2)... 05......- 12 12-7 10 — Breadth of m.2 ........ 10 12 10 Mandibular or goniac angle . 110° 110° | — 110° Norr.—Unless otherwise stated, the numerals denote millimetres. Measurements of the fossil skulls cannot be made with great precision, and there are often dis- crepancies between the results of different authors. For the Gibraltar and Austra- lian skulls the figures are chiefly those of Prof. Sollas; for Neanderthal those of Dr. Schwalbe ; for La Chapelle those of Prof. Boule; and for Spy chiefly those of MM. Fraipont and Lohest. Some of the measurements of the Australian skull have been kindly taken by Mr. E.S. Goodrich, F.R.S. The estimates of cranial capacity of the Gibraltar and Spy skulls are those of Prof. A. Keith. The measure- ments of the Heidelberg mandible are by Dr. O. Schoetensack. Vol. 69.| THE HUMAN SKULL, ETC. FROM PILTDOWN. 131 the insertion of a powerful masseter muscle (ma.). The horizontal portion, or body of the mandibular ramus, measures only about 27 mm. in depth behind, but must have become a little deeper forwards. External to the first and second molars there is the usual prominent oblique ledge (6.) for one of the origins of the buccinator muscle; but this is the only feature visible on the outer face, a large flake of bone behind the position of the mental foramen having been lost when the anterior part was broken. Seen from within, the ascending portion of the ramus is remarkable for the thickening of its anterior margin, to provide a large surface (¢.) for the insertion of the temporal muscle as far downwards as the alveolar border. A strengthening ridge extends downwards and forwards from the articular condyle to the lower part of the sharply- defined inner edge of the temporal surface. Below and behind this the large dental foramen (d.) occurs, though its shape is altered by accidental breaking; and still a little lower there is the slight impress of the mylohyoid groove (m.g.). Near the angle (i.pt.) might be expected a roughness for the insertion of a powerful internal pterygoid muscle; but the bone bears only slight irregularities and it is very little curved inwards. Farther forward the inner face of the ramus is curiously smooth, the origin of the mylohyoid muscle, which forms so conspicuous a ridge in man, being not marked even by a faint line. The great width of the temporal insertion, the situation of the mylohyoid groove behind rather than in line with the dental foramen, and the complete absence of the mylohyoid ridge are all characters of the mandible in apes, not in man. It is, therefore, very interesting to note that as the ramus curves round to the symphysis (s.) its lower margin exhibits an increasingly wider flattening, which begins beneath the second molar, slopes upwards and outwards, and ends in front in a strongly retreating chin. The inner edge of this flattening is sharply rounded, and at the symphysis itself the inner face of the jaw is so much depressed in its lower part that the bone here has the form of a nearly horizontal ‘plate or flange, closely similar to that found in all the apes. The genio-hyo-glossal and genio-hyoid muscles, in fact, must have had their origin in a deep pit, as in the apes; while the digastric can only have been inserted on the edge of the bony flange, instead of extending far over the lower border as in man. The absence of the upper part of the symphysis in the fossil is therefore particu- larly unfortunate, and there is ample scope for speculation as to the precise shape of the bony chin and the extent of the anterior part of the alveolar border. The fractured end does not even suffice to determine whether or not the part preserved reaches the middle line; it merely shows that the walls of the jaw. are thin, and that the inner tissue must have been coarsely cancellous. As, however, the whole of the bone preserved closely resembles that of a young chimpanzee, it seems reasonable to restore the fossil on this model, and make the slope of the bony chin intermediate between that of the adult ape and that of Homo heidelbergensis. KZ 4 132 THE HUMAN SKULL, ETC. FROM PILTDOWN. [| March 1913. If this restoration prove to be correct, the length of the alveolar border in front of the molars is 60 mm., instead of 30 to 40 mm., as in all known human jaws; and it seems difficult to fill this space without assuming that a relatively large canine was present. That the canine in any case cannot have been very prominent, seems to be proved by the remarkable flatness of the worn surface of the molar teeth (Pl. XX, fig. 2c: m. 1, m. 2). Enamel and dentine have been equally worn down by very free movements in mastication, and such a marked regular flattening has never been observed among apes, though it is occasionally met with in low types of men. Although the cusps have been worn down to the plane of the central area in each tooth, very little dentine is exposed—much less, in fact, than is seen in the similarly worn teeth of apes. Both the first and second molars are noteworthy for their considerable length in proportion to their width, each being provided behind with a large fifth cusp. They are constricted in the ordinary manner at the base of the crown (figs. 2 & 2a, m.1, 2), and in each tooth the two divergent roots are completely separate to their upper end. They are thus very different from some human teeth with fused roots which are claimed to be of Paleolithic age.” The first molar measures 11:5 mm. in length by 9°5 mm. in width; while the second molar is larger by 0°5 mm. in each direction. The third molar, which is situated almost completely on the inner side of the ascending portion of the jaw, is represented only by its well-preserved socket (fig. 2c, m.3), which shows that its two divergent roots resembled those of the other molars in not being fused together. The anterior root must have been wider than the posterior root, and impressed by a vertical median groove along its hinder face. The posterior root is shewn to have been the thicker antero-posteriorly. The tooth must have been relatively large, not less than 11 mm. in length, and inclined a little inwards. The molar teeth, therefore, although distinctly human, are of the most primitive type, and must be regarded as reminiscent of the apes in their narrowness. The first molar may be compared with a detached specimen already known from Taubach, in Saxe- Weimar.” A restored model of the mandible, skilfully made to fit the skull by Mr. Frank O. Barlow, is shown from the left side and from above and below in text-figs. 4-6 (pp. 183-37). It assumes that the actual fossil extends just to the symphysis, and the result is © distinctly striking. The jaw is rather wide, but the nearly straight molar-premolar series of the two sides converge only gradually forwards ; while both canines and incisors are, of necessity, large and spaced. While the skull, indeed, is essentially human, only approaching a lower grade in certain characters of the brain (see pp. 145-47), in the attachment for the neck, the extent of the temporal muscles, 1 Homo neanderthalensis var. krapinensis, Kramberger, Mitth. Anthrop. Gesellsch. Wien, 1902, p. 191. Homo breladensis, Keith & Knowles, Journ. Anat. & Physiol. vol. xlvi (1911) p. 12. 2 A. Nehring, Zeitschr. fiir Ethnologie, 1895, p. 838. Fig. 4.— Restoration of the Piltdown mandible (B), compared with that of man (C) and the young chimpanzee (A), in left side view ; two-thirds of the natural size. nS FA J — Maier iy: ea een NS iN ) iW) No\Guent +S ny \ Be ee cE [= PA ANN ad \ Sa27 A ee \ \ \ Fig. 5.—Restoration of the Piltdown mandible (B), compared with that of man (C) and the chimpanzee (A), upper view ; two-thirds of the natural size. \ ==> Sa wo HS Lae AN ZG Ni, tog iod a I Dy 2 SN D MeN) Bo) 5 AT) ECON a AIL AG eC fede er t c ee ea Coto Vol. 69.] THE HUMAN SKULL, ETC. FROM PILTDOWN. 135 and in the probably large size of the face, the mandible appears to be almost precisely that of an ape, with nothing human except the molar teeth. Even these approach the ape-pattern in their well- developed fifth cusp and elongated shape. The specimen, therefore, represents an annectant type, and the question arises as to whether it shall be referred to a new species of Homo itself, or whether it shall be considered as indicating a hitherto unknown genus. The brain-case alone, though specifically distinguished from all known human crania of equally low brain-capacity, by the characters of its supraorbital border, and the upward extension of its temporal muscles, could scarcely be removed from the genus Homo; the bone (Fig. 5 cont,) C. of the mandible so fur as preserved, however, is so completely distinct from that of Homo in the shape of the symphysis and the parallelism of the molar-premolar series on the two sides, that the facial parts of the skull almost certainly differed in fundamental characters from those of any typically human skull. I therefore propose that the Piltdown specimen be regarded as the type of a new genus of the family Hominide, to be named Hoanthropus and defined by its ape-like mandibular symphysis, parallel molar- premolar series, and narrow lower molars which do not decrease in size backwards ; to which diagnostic characters may probably be added the steep frontal eminence and slight development of Fig. 6.—Restoration of the Piltdown mandible (B), compared with that of man (C) and the chimpanzee (A), lower view ; two-thirds of the natural size. Dy re or 7” Vol. 69. ] THE HUMAN SKULL, ETC. FROM PILTDOWN. 137 brow-ridges. The species of which the skull and mandible have now been described in detail may be named Hoanthropus dawsoni, in honour of its discoverer. The differences between the mandible of #. dawson: and other primitive human mandibles hitherto discovered are very remarkable; but they are especially striking when comparison is made between the new specimen and the mandible of Homo heidelbergensis (fig. 7, p. 138). These two jaws can be very satis- factorily compared: because the first and second molars are almost identical in length in the two specimens, and their outline may be (Fig. 6 cont.) C. LEE — Lo yp = = —S——— yyy) | exactly superposed, as shown in fig. 7. While separated by the characters of the inner face and symphysis already noted (p. 131), the mandible of Hoanthropus dawsomi is thus seen to differ also in its comparative slenderness and its regular deepening to the sym- physial end; and, whereas the anterior teeth of the new specimen must have occupied a space of about 60 mm., those of Homo heidelbergensis have only the usual extreme human extent of 40mm. When it is remembered that Hoanthropus dawsont and H. heidelberyensis are almost (if not absolutely) of the same geo- logical age, we are thus led to the interesting conclusion that at 1 Q. Schoetensack, ‘Der Unterkiefer des Hoio heidelbergensis’ Leipzig, 1908. 138 DR. A. SMITH WOODWARD: DESCRIPTION OF [March 1913, the end of the Pliocene Epoch the representatives of man in Western Hurope were already differentiated into widely divergent groups. The skull is equally remarkable when compared with the other undoubtedly ancient human skulls hitherto known, and suggests generalizations of even wider import. The discoveries of the brain-case of Pithecanthropus and several skulls of the Mousterian (Neanderthal) type have led to the very general belief that early man was characterized by a low, flattened forehead and a prominent bony brow, like the corresponding parts in the adult existing apes. The only opinions to the contrary have been based on discoveries of very doubtful authenticity, or on theoretical considerations which still need to be tested by more facts. Now, the Piltdown specimen, which is certainly the oldest typically-human brain-case Fig. 7.—Mandibular ramus from Piltdown superposed on that of Homo heidelbergensis ; two-thirds of the natural size. 4) 4 y | GY SZ, hitherto found, exhibits no anterior flattening, but has the frontal eminence as steep as in modern man, without any prominent supra- orbital ridge. The small development of this ridge may possibly be due in some degree to the circumstance that the new specimen represents a female, as suggested by the small backward extent of the temporal muscles, the weakness of the mandible, and the rela- tively small size of the mastoid processes. ven so, however, a full- erown male of the same race could not have developed a supraorbital prominence approaching that of Mousterian man. The conclusion seems therefore inevitable, that at least one type of man with a high forehead was already in existence in Western Europe long before Mousterian man, with a low and prominent brow, spread widely in this region. It is also clear that this earlier man had a much lower cranial capacity than most examples of the Jater low-browed man. Weare thus reminded of the interesting fact Vol. 69.] THE HUMAN SKULL, ETC. FROM PILTDOWN. 139 that, during the post-natal life of all the existing apes, the skull has at first the curiously rounded shape of the Piltdown specimen, with a high frontal eminence and scarcely any brow-ridge ; while as growth proceeds a postorbital constriction begins, the bony brow grows forwards, the forehead becomes flattened, and the familiar well-marked ape-skull is the result (fig. 8, p. 140). Our knowledge of the principles of paleontology compels us to suppose that the full-grown skull in the ancestral mid-Tertiary apes was of the immature rounded shape just mentioned, although we have not yet been fortunate enough to discover an example; and, during the lapse of Upper Tertiary time, the skull-type in the whole race of apes has gradually undergone changes which are more or less exactly recapitulated in the life-history of each individual recent ape. Hence, it seems reasonable to interpret the Piltdown skull as exhibiting a closer resemblance to the skulls of the truly ances- tral mid-Tertiary apes than any fossil human skull hitherto found. If this view be accepted, the Piltdown type (fig. 9, p. 141) has gradually become modified into the later Mousterian type (fig. 10, p- 141) by a series of changes similar to those passed through by the early apes as they evolved into the typical modern apes, and corresponding with the stages in the development of the skull in an existing ape-individual. It tends to support the theory that Mousterian man was a degenerate offshoot of early man, and probably became extinct; while surviving man may have arisen directly from the primitive source of which the Piltdown skull provides the first discovered evidence. For much valuable help in studying these human remains I wish especially to thank Mr. W. P. Pycraft, A.L.S., and Mr. Arthur S. Underwood, M.R.C.S. The Associated Mammalia. The associated mammalian remains are well mineralized with oxide of iron, and, as might be expected in so coarse a gravel, they are all very fragmentary. Masropon (PI. X XI, figs. 1, 1 a, & 1 6).—A much-rolled specimen is readily identified as the cusp of a molar of Mastodon, of the same type as V/. arvernensis. ‘The outer enamel, with the charac- teristic irregularities, is well preserved, and the waterworn base shows the upper end of the large pulp-cavity. ‘The cusp has three apices closely pressed together, the median one being relatively small and crushed between the others ; and the fossil is sufficiently complete to show that it was an isolated eminence on a tooth, not part of a continuous ridge. Srrcopon (Pl. XXI, figs. 2, 2a, 3, & 3a).—Two fragments of a large Proboscidean molar, which have evidently been broken with great force but are scarcely rolled, are referable to a very primitive type of true elephant. One piece (figs. 2 & 2a), in which the 140 DR, A. SMITH WOODWARD: DESCRIPTION or [March 1913, Fig. 8.—Outlines (left lateral view) of the skull and mandible oF the young and adult chumpanzee ; half of the natural size. Xl I) ara oan: Bee byl unt Ei NY WP Re i, | { y O, i lf t) Ea Te Ze Ne ag i “ffi ff ‘i Ue A 7 aa Aang AN if CN ina para ! ‘ial z ————— Vol. 69. ] THE HUMAN SKULL, BTC. FROM PILTDOWN. 141 Fig. 9.—Outline (left lateral view) of the skull and mandible of Hoanthropus dawsoni, with the bones of the face and the symphysis of the mandible in dotted outline. (4 nat. size.) ‘( 1 i] 1 2 (Zea=—~ = Fig. 10.— Outline (left lateral view ) of the human skull and mandible from La Chapelle-aua-Saints, after M. Boule. (4 nat. size.) JISX. WW, ? NN | | x ay Y % ; , me : Yo \ [ h, (AA ll bie CT | f A | ' \ ow, ye SSE j @ = 142 DR. A. SMITH WOODWARD: DESCRIPTION oF [March 1913, ridges are subdivided into round digitations, seems to belong to the hinder part of a molar just coming into wear; while the smaller piece (figs. 3 & 3a), perhaps of the same tooth, represents the much- worn middle or anterior portion, with the enamel very wavy in section. Both specimens fortunately exhibit a complete valley in cross-section (figs. 2a@ & 3a), and so allow the angle of divergence of the ridges to be determined. In the hinder fragment this angle measures about 20°, in the other a little more; and in each case the walls of the valley are divergent to the summit, not parallel in the upper part. The valleys are thus very wide in proportion to their depth, and the tooth evidently belongs to that primitive section of the genus Llephas to which Falconer gave the name of Stegodon. It cannot be referred to the Upper Pliocene Hlephas meridionalis, because in this species the valleys are deeper in pro- portion to their width, while the ridges are more plate-like and parallel in their upper portion. The new specimen is, therefore, of an earlier Pliocene type, which is best known from the Siwalik Formation in India, and has not hitherto been found in Western Europe.” Hrevororamus (Pl. XXI, figs. 4,5, & 5a).—The broken middle portion of a left lower molar (probably m, 3) of Hippopotamus (fig. 4) agrees well in size and pattern with many of the corresponding teeth of the ordinary 1. amphibius, and may probably be referred to this species. It is only peculiar in exhibiting a small tubercle in the valley on the outer side—an addition which occasionally occurs in more than one species. There is also an example of the first lower premolar (figs. 5 & 5a), with the usual undivided root. Its crown bears the characteristic fine rugosity, with a trace of the cingulum at the base. Both these teeth are much worn by mastication, and they may have belonged to the same individual. Cervus ELAPHUS (Pl. XXI, figs. 6 & 6 a).—The base of a large left antler of the common red deer is remarkable for its smoothness, only slight traces of the usual longitudinal furrowing being visible near the burr, which is coarse and prominent. The boneis flattened antero-posteriorly, the hinder face being especially flat, and the plane curving forwards at the origin of the lower brow-tyne. On its anterior face (fig. 6) a rounded longitudinal ridge rises near the outer margin upwards to a thickening at the origin of the upper brow-tyne. The diameter of the base of the beam within the burr is about 70 mm., and the height to the origin of the second brow- tyne is 120 mm. The collection also includes the proximal end of a metatarsal of Cervus split longitudinally (see p. 121). 1 Q. J. G.S. vol. xxi (1865) p. 258. 2 A form of Proboscidean tooth nearly as primitive as that from Piltdown has been recorded from the Pliocene of Lower Austria ; see G. Schlesinger, Monatsbl. Verein. Landeskund. Niederdsterr. 1911, No. 16. Vol. 69.| § THE HUMAN SKULL, ETC. FROM PILTDOWN. 143 Eeuus.—A first or second left upper molar of an aged horse cannot be specifically determined. The tooth is as broad as long, its enamel is scarcely crimped, and the extent of its inner column is slightly less than half of the antero-posterior measurement of the tooth. Casror Fiper (Pl. XXI, figs. 7, 7 a, & 8)—A lower molar and a lower fourth premolar of a beaver, referable to the genus Castor, agree exactly with the corresponding teeth of the Pleistocene and existing species, C. fiber. They exhibit no plication of the enamel such as occurs in the Upper Pliocene C. plicidens.' Of these mammalian remains, the fragment of tooth of Mastodon is so much more waterworn than the others that it may be regarded without hesitation as having been derived from some older deposit. The broken pieces of Stegodon must also have been extremely battered by transport, if their fracture is really natural and not due to the carelessness of workmen. It seems likely, therefore, that these typically Pliocene fossils are of earlier date than the deposi- tion of the Piltdown gravel. The teeth of Hippopotamus, however, may beeither Upper Pliocene or Pleistocene in age ; while the teeth of Castor are most probably Pleistocene, and typical specimens of Cervus elaphus have never hitherto been found below the Pleistocene. Although, therefore, the mammalian remains do not determine the ‘age of the gravel with certainty, they tend to assign it to the Pleistocene Epoch; and, when it is remembered that (as pointed out by Mr. Dawson, p. 123) most of the contained ‘ Koliths’ are waterworn, while the associated rude Paleolithic implements have sharp edges, it seems more reasonable to date the deposit by the latter than by the former. If, as the result of these considerations, the gravel proves to have been formed in an early part of the Pleistocene Epoch, the age of the human remains is also decided ; for they are very little waterworn, and the skull and mandible would not have occurred in close association if they had been transported far from the spot at which they were originally - entombed. EXPLANATION OF PLATES XVIII-XXI. Prater XVIII. Koanthropus dawsoni, gen. et sp. nov.; from a gravel near Piltdown Common, Hletching (Sussex). Fig. 1. Restored model of skull, upper view. 2 Do. do. do. front view. 3. Do. do. do. left side view. 4. Do. do. do. back view, [All the figures are of half the natural size, and the darkly-shaded parts indicate the pieces of bone actually preserved. | * CO, I. Forsyth-Major, Proc. Zool. Soc. 1908, pp. 630-31, text-fig. 132. 144 THE HUMAN SKULL, ETC. FROM PILTDOWN. {March rg13, PuatTs XIX. Hoanthropus dawsoni, gen. et sp. nov.; from a grayel near Piltdown Common, Fletching (Sussex). Big. 1. Left frontal in outer side view; (1 @) front view and (1 4) lower view of the lateral portion. cer. = cerebral surface; cor. = coronal suture; ¢.a.9. = external angular process; m.f.=facette for malar; orb.=roof of orbit; s.=broken section of frontal bone; s.f.=facette for sphenoid; ¢.=temporal ridge. 2. Left temporal, lacking the upper part of the squamous wing, in outer view ; (2a) lower view, (20) inner view, and (2c) upper view. car.=openings of carotid canal, the lower blocked by a pebble; e.a.m.=external auditory meatus, blocked by a pebble; g/.=glenoid fossa ; 7.a.m.=internal auditory meatus; mal.=process for malar ; mast.=mastoid process; 0,f.= suture for occipital; p.a.p.=post- articular process ; p.f.=suture for parietal ; s,/.=suture for sphenoid ; s?.=broad groove for lateral sinus ; s/.=base of styloid process. [All the:figures are of the natural size. | PLatTe XX. Hoanthropus dawsoni, gen. et sp. noy.; from a gravel near Piltdown Common, Fletching (Sussex). Big. 1. Imperfect occipital in outer view; (1@) inner view and (10) broken vertical section, left side. ceb.=cerebellar fossa; cer.=cerebral fossa; ¢.o.c.=external occi- pital crest; ¢.0.p.=external occipital protuberance ; fmag.=foramen magnum; 7.0.c.=internal occipital crest; Jamb.=portion of lamb- doid suture; /.c.l.=lower curved line; /.s.=linea suprema; s7.= groove for lateral sinus; w.c./.=upper curved line. 2, Right mandibular ramus, imperfect at the symphysis, in outer view; (2 a) inner view, (20) lower view, and (2c) upper view. 6.=ridge below origin of buccinator muscle ; cd.=neck of condyle ; cor.=coronoid process; d.=inferior dental foramen ; 7.pt.=area of insertion of internal pterygoid muscle; mm. 1, m.2=first and second molars; m.3—= socket for third molar; m.g. = mylohyoid groove; ma.—=area of insertion of masseter muscle; s.=incurved bony flange of symphysis ; ¢.=area of insertion of temporal muscle. [All the figures are of the natural size. | Prave XXI. Mammalian remains found with Hoanthropus dawsoni, mm a gravel near Piltdown Common, Fletching (Sussex). Fig. 1. Mastodon sp.: waterworn cusp of molar tooth, side view; (1a) front view and (16) back view. (See p. 139.) 2. Stegodon sp.: hinder fragment of molar tooth, crown view; and (2a) vertical longitudinal section. (See p. 139.) 3. Stegodon sp.: fragment of molar tooth worn by mastication, crown view ; and (3 a) vertical longitudinal section. (See p. 142.) 4. Hippopotamus sp.: crown view of portion of lower molar tooth. (See . 142. 5. Eo cin sp.: lower first premolar, outer view ; and (5 a) end view. 6. Cervus elaphus Viinn.: basal fragment of left antler, front view; and (6 a) outer view, three-quarters of the natural size. (See p. 142.) 7. Castor fiber: first or second right lower molar, crown view; and (7 a) outer view. (See p. 143.) 8. Castor fiber: right lower fourth premolar, crown view. [All the figures are of the natural size, except figs. 6 & 6a.] | Quart. Journ. Ggor. Soc. Vor. LXIX, PL. XIX. G. M. Woodward, del. Bemrose, Collo, Derby, EOANTHROPUS DAWSONI. Ps Z 4 a i , _ % ee fe r : O F , 5s “ ss if My oa “y ‘ 5 % ue Sa < f ; ~ asf | =, — — a - 2 ~ LOC | Quart. Journ. Geot. Soc. Vor. LXIX, Pu. XX. TLL 12. G.M. Woodward, del. Bemrose, Collo, Derby, EOANTHROPUS DAWSONI. are : ne AN eile aT Sete pt me sm in : 4 Rt a d : i - 2 Quarr. Journ. ‘Bes Soc. Vor. LXIX, Pc. XVIII. G.M. Woodward, del Bemrase, Callo, Derby. EOANTHROPUS DAWSONI. Quart. Journ Geor. Soc. Vor. LXIX, Pv. XXI. 6. M. Woodward, del. Bemrose, Collo, Derby MAMMALIAN REMAINS) found with EOANTHROPUS DAWSONI. Vol. 69.] THE HUMAN SKULL, ETC. FROM PILTDOWN. 145 Apprnpix.— Preriminary Report on the Crantat Cast. By Grarron Exxiior Smita, M.A., M.D., F.R.S., Professor of Anatomy in the Victoria University of Manchester. Tur observations recorded in these notes were made upon the eranial cast which was submitted to me for examination by Dr. Smith Woodward, under whose direction the remains of the cranium were fitted together and the cast obtained from it. The accompanying sketch (fig. 11) represents the left norma Fig. 11.—Left norma lateralis of the internal cast of the skull from Piltdown. Sinus of Breschet Ramus praeobelicus —___ Ramus obelicus Polus temporalis inferior lateralis, and will explain better than a description the extent of missing cranial wall. The greater part of the right parietal bone and a considerable part of the occipital were found, and it was possible to fit them into position. ‘Thus the form and proportions of the whole brain can be estimated. The sharply-cut meningeal grooves upon the bones have pro- duced upon the cast the whole pattern of the middle meningeal veins and arteries with great distinctness. The diagram shows the arrangement upon the left side: upon the right it conforms to Giuffrida-Ruggeri’s Typus 1.’ Unfortunately, there are only very slight indications of the * ‘Ueber die endocranischen Furchen der Arteria meningea media beim Menschen’ Zeitschr. f. Morph. & Anthropol. vol. xv (1912) p. 408. Oo One, No. 273: L 146 PROF. G. ELLIOT SMITH ON THE HUMAN [March 1913, arrangement of the furrows upon the surface of the cerebral hemi- sphere. Nevertheless many of them can be detected, if not by sight, by passing the finger over the surface and locating the depressions by touch. These features are represented (with con- siderable exaggeration so far as depth of shading is concerned) in the diagram (fig. 11) on the preceding page. At first sight, the brain presents a considerable resemblance to the well-known Paleolithic brain-casts, and especially to those obtained from the Gibraltar and La Quina remains, which are supposed to be women’s. Like these casts this one is relatively loug, narrow, and especially flat; but it is smaller, and presents more primitive features than any known human brain or cranial cast. The position and relations of the cerebellum present a marked contrast with those exhibited in the La Chapelle-aux-Saints, La Quina, and Gibraltar casts; the frontal and parietal regions are less expanded, and the temporal region cxhibits some important and very significant differences. The length of the left cerebral hemisphere (which was probably a little longer than the right, because the left occipital pole was the more prominent, a condition found in the brains of modern right-handed men)’ is 163 mm. The breadth in the frontal region (just below the point marked a) is 101 mm.: the maximum breadth of the hemispheres is at the point T, low down on the temporal area, and measures 130 mm.; but at the point P in the parietal region, corresponding to the place where anthropometrists measure the breadth of the skull, the breadth of the brain-cast is only 102 mm. The maximum height, measured from the [restored] tip of the curiously pendent temporal region (designated ‘ Polus temporalis inferior,’ to distinguish it from the temporal pole of the modern man’s brain), is 166 mm. ; but farther back (opposite T) the height sinks to 86 mm. In this note I do not propose to discuss the significance of the faint glimmerings which this cast affords of the pattern of the con- volutions, except to remark that there are indications sufficiently definite to enable us to plot out a great part of the singularly primitive arrangement of sulci. I have already referred to the diminution and flattening of the frontal and parietal regions. In the centre of the latter there is an area, which is well circumscribed by recognizable sulci (s, 1, /, v, and oa), raised up into a low hillock, the summit of which is at the point marked P. It is more pronounced on the right hemi- sphere. This indication of the expansion of an area, the large dimensions and fulness of which are especially characteristic of the human brain, is peculiarly significant, when taken in con- junction with a similar condition in the temporal region. One of the most striking features of this brain-cast is the deep ? On the Asymmetry of the Caudal Poles of the Cerebral Hemispheres & its Relation to the Occipital Bone’ Anat. Anzeiger, vol. xxx (1907) p. 574. Vol. 69.] SKULL FROM PILTDOWN. 147 excavation of the temporal area, to form the wide bay between the inferior temporal pole and the cerebellum. ‘This is due to the marked attenuation of the temporal region ; but, as we have already seen in. the case of the parietal region, so also here are definite sigus. that the expansion has begun which eventually will trans- form this area into the very different configuration that it presents in the modern brain. There is a very prominent, elliptical swelling, the summit of which (at T) is raised more than a centimetre above the level of the surrounding cortex. It is 2 centimetres in vertical measurement and almost 3 centimetres long. This peculiar con- formation assumes quite a special interest when it is remembered that this obviously expanding area occupies the position where in the modern human brain is developed the territory which recent clinical research leads us to associate with the power of ‘spon- taneous elaboration of speech and the ability to recall names’ (Adolf Meyer). The configuration of the anterior part of the temporal area is also peculiar, thongh a suggestion of the same kind of form is seen in the Gibraltar brain-cast. Below the point marked / the surtace slopes inwards towards the mesial plane, so that the fulness of the temporal pole of the modern brain is wanting, There is marked asymmetry of the cerebellum and of the occi- pital poles of the cerebrum, Taking all its features into consideration, we must regard this as being the most primitive and most simian human brain so far recorded; one, moreover, such as might reasonably have been expected to be associated in one and the same individual with the mandible which so definitely indicates the zoological rank of its original possessor. The apparent paradox of the association of a simian jaw with a human brain is not surprising to anyone familiar with recent research upon the evolution of man. In the process of evolving the brain of man from the ape the superficial area of the cerebral cortex must necessarily be tripled; and this expansion was not like the mere growth of a muscle with exercise, but the gradual building-up of the most complex mechanism in existence. ‘The growth of the brain preceded the refinement of the features and of the somatic characters in general. Discussion. Sir Ray Lanxuster congratulated the Authors on the very clear and interesting account given by them of their important discovery. Two distinct questions arose in regard to the bones discovered : first, what are the characters of skull and jaw indicated, and, secondly, what is the geological age of the specimens? He had been allowed 1o examine the jaw and skull some weeks ago, and with Mr. Dawson had visited the locality where they were found. In regard to the zoological characters of the individual indicated by the bones—eyerything depended on the little projecting piece at the 148 THE HUMAN SKULL, ETC. FROM PILTDOWN. { March 1913, broken front end of the mandible, proving the existence of a long © and flattened symphysis as in the chimpanzee. He considered that Dr. Smith Woodward was fully justified in the conclusion which he drew from this portion of the specimen as to the ape-like character of the completed jaw and of its dentition; and, though the restoration of the jaw on this basis undertaken by Dr. Smith Woodward was a very bold step, he considered that it was justified. He considered that this lower jaw presents simian characters distinct from, and more decisive than, those of the Heidelberg jaw. As to the age of the specimens, he did not think that any conclusion could be arrived at; for the human bones might be earlier than the flints and as early as the Mastodon tooth, or later than either. He did not consider it certain that the lower jaw and the skull belonged to the same individual; and hence no convincing argument as to their age could be drawn from their juxtaposition in the gravel. He would prefer not to use the word ‘ Eolith’ to describe any flint-implement, or supposed flint-implement. Those called ‘Koliths’ by Mr. Dawson resembled (as did many pieces of the flint) the flints of the High Plateau-gravel of Ightham. The coarsely-worked triangular and irregular flints found in the gravel were certainly of a difterent character, and probably later. But he did not agree to their being termed ‘ Chellean * or ‘ early Chellean.? Chelles was simply a locality, and there was no definite ‘form’ of flint-implement which had been designated by the word * Chellean.’ It was better to describe the forms of flint-implements, without making use of names for them which had no authorized and aveepted meaning and might lead to misunderstanding. Prof. A. Kurrn regarded the discovery of fossil human remains just announced as by far the most important ever made in England, and of equal, if not of greater consequence than any other discovery yet made, either at homeorabroad. He agreed that the reconstruc- tion of the skull had been executed with great skill, the only point in the restoration about which he was not convinced being the chin-region of the mandible and the form of the incisor, canine, and premolar teeth. The restoration approached too nearly the characters of the chimpanzee. The very simian characters of the sub-symphysial region of the mandible, the undoubtedly large anterior teeth, the primitive characters of the skull and brain, seemed to him altogether incompatible with the Chellean age assigned by the Authors. In his opinion the skull must be assigned to the same age as the mammalian remains, which were admittedly Pliocene. In the speaker’s opinion, Tertiary man had _thus been discovered in Sussex. In coming to this conclusion the speaker was influenced by the fact that in the Heidelberg jaw, which was of early Pleistocene date, the symphysial region of the jaw was essentially human in its markings and characters ; whereas the same features in the remains just described were simian, and therefore presumably much earlier. Prof. Boyp Dawkins said that he agreed with the Authors of the paper that the deposit containing the human remains belonged Vol. 69. | THE HUMAN SKULL, ETC. FROM PILTDOWN. 149 to the Pleistocene age, and that the Pliocene mammalia in it— Mastodon arvernensis and the rest—had been derived from a Pliocene stratum formerly existing in that area. The latter were merely adventitious, and were no proof of the Pliocene age of the stratum. The Paleolithic implements were, in his belief, of the same age as the human bones. There was no connexion between the faculty of speech and the capacity for making implements, as was urged by the lust speaker. The evidence was clear that this discovery revealed a missing link between man and the higher apes, appearing at that stage of the evolution of the higher mammalia in which it may be looked for—in the Pleistocene age. ‘The modern type of man had no place in this age. He congratulated the Society on having had the clear and lucid statement of the Authors supplemented by the valuable remarks of Prof. Elliot Smith, the highest authority on the human brain. Dr. Duckworrn agreed entirely with the Authors as to the importance of the Piltdown skull, and also as to its general significance. It was justifiable to associate the various fragments as parts of one human skull; and the simultaneous presence of so many simian characters in one and the same specimen was a point of great significance. Almost any one of those characters might be detected singly in human crania of existing types, especially if search were directed to the more lowly of those. Even the mylo- hyoid ridge was not so constant as Dr. Smith Woodward suggested. But, so far, the search made by the speaker for a flange-like con- formation in a human jaw had been quite unsuccessful. This character, even alone, possessed accordingly the great importance attiibuted to it by Dr. Smith Woodward. On the anatomical side, the Piltdown skull realized largely the anticipations of students ct human evolution. ‘To fulfil those anticipations completely, the problem of the precise antiquity of the skull required solution. Anatomists would, therefore, await eagerly the conclusions formed by geologists on this aspect of the subject. Mr. Crement Retp observed that no detailed ‘drift survey * had yet been made of’ this particular area, but perhaps the survey of the Sussex coastal plain might throw light on the age of the deposit at Piltdown. In the coastal plain the Pleistocene deposits fall into three main groups. At the bottom is the erratic deposit of Selsey, probably contemporaneous with the Chalky Boulder Clay. Above comes a series of interglacial deposits showing varying climates and varying amounts of submergence, the submergence culminating in the Goodwood raised beach, at 135 feet above the sea, and passing away in the lesser submergence shown by the raised beach of Brighton. Above all these marine and fluviomarine deposits lies the great sheet of Coombe Rock, which shows a recurrence of Arctic conditions, perhaps dry cold. The uppermost Pleistocene deposit is probably of Mousterian date. The speaker tried to trace these deposits of the coastal plain continuously, through the valleys which breach the South Downs, into the Wealden area, but without much success. It seemed, 150 THE HUMAN SKULL, ETC. FROM PILTDOWN. [ March 1913, however, that the low plateau of the Weald, on which the Piltdown deposit probably lies, must belong to a period later than that of maximum depression, for otberwise these lowlands of the Weald would be covered by marine deposits, as is the coastal plain. It was ~ impossible to speak with confidence, but the whole of the evidence suggested that the Piltdown deposit and the plateau on which it rests belong to a base-level plain, which originated about the period of the Brighton raised beach. The deposits are not pre-Glacial or even early Pleistocene—they belong to an epoch long after the first cold period had passed away; but they occur at the very base of the great implement-bearing succession of Paleolithic deposits im the South-East of England. Prof. Warrerston pointed out that, if the reconstruction of th cranium and mandible were accepted, it was quite clear that the former was human in practically all its essential characters ; while the latter with equal clearness resembled, in all its details, the - mandible of the chimpanzee. It was, therefore, very difficult to believe that the two specimens could have come from the same individual. One of the temporal bones, including the glenoid fossa, was complete, and Dr. Smith Woodward had pointed out how closely this bone and the fossa resembled the corresponding parts in modern man. It must be borne in mind that the configuration of the glenoid fosse in man was such as to adapt them for articulation with a human jaw, and not with the mandible as found in the chimpanzee; and, if the jaw had formed part of the skull, it was precisely in the temporal bone that one would have anticipated some variation in structure from the present-day condition. Mr. A.S. Kenwarp was of opinion that the gravel-spread in which the remains were found should be correlated with the High Terrace of the Lower Thames Valley: the height above the present stream- level was practically the same, and the flint-implements were identical. With regard to the Pliocene age of some of the fossils from Sussex, it must be remembered that the High Terrace of the Thames has yielded several characteristic Pliocene forms. ‘The true succession of the Pleistocene had yet to be worked out, and it must be based on paleontological evidence. Mr. Reernatp Smirx remarked that the flint-implements re- covered were of mixed character, and the only course was to date the gravel by the latest specimen. Those exhibited were of the Chelles stage, if not earlier ; and, to judge from the photographs shown on the screen, there were hand-axes of the St. Acheul stage in an unrolled condition. While it required a developed brain to manufacture such implements, it was surprising to find so simian a jaw in the later part of the river-gravel period, and the dilemma still remained. It was a misfortune that the Geological Survéy had not visited that area of the Weald in recent years, as it would be interesting to know the relation of the present deposit to the Limpsfield gravel with its homogeneous and well-made implements, ADMISSION AND PRIVILEGES OF FELLOWS OF THE GEOLOGICAL SOCIETY OF LONDON. Every Candidate for admission as a Fellow must be proposed by three or more Fellows, who must sign a Certificate in his favour. The Proposer whose name stands first upon the Certificate must have a personal knowledge of the Candidate. Fellows on election pay an Admission Fee of Six Guineas. 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Fellows may purchase one Copy of this Book at 2s. Additional Copies will be charged 4s. [Postage 5d.] CONTENTS. Pages Proceedings of the Geological Society, Session 1912-15, including the Pro- ceedings at the Annual General Meeting, the President’s Anniversary Address Mote! wes, Hesse eae, cho eh cadena otas de Dee Fae ane ae ee i-xcii PAPERS READ. Page 1. Dr. J. H, Marr on the Lower Palzozoic Rocks of the Cautley District ......... 1 2. Mr. H. W. Monckton on the Hafslo Lake and the Solvorn Valley (Plate I)... 19 3. Mr. E. 8. Cobbold on the Trilobite Fauna of the Comley Breccia-Bed (Plates TDG U1) |... ci scecacoccsenecaeseat qusvenpanetes ses sane coe tes ot ee en eeee eee 27 4. Mr. E. §. Cobbold on Two Species of Paradoxides from Neye’s Castle (Blate, TV) osstvcnceeledcaseeawsiak os guncee doses oven cuedaes cee scien cocse oan des meeenee pea 45 5. Mr. Stanley Smith on the Genus Aulophylium (Plates V-IX) ........-..seceeeeeee 51 6. Mr. E. Proctor on Fossiliferous Old Red Sandstone from the Southall Boring, with an Appendix on the Fish-Remains by Dr. A. 8. Woodward (Plate X) 78 7. Prof. A. C. Seward on Wealden Floras (Plates XT-XIYV)..........0...cceeeeceneces 85 S, Mr. C. Dawson & Dr. A. S. Woodward on the Human Skull and Mandible discovered at Piltdown (Plates XV—XX1) ...........scecececscececssnccseccocecerss 117 [No. 274 of the Quarterly Journal will be published next June. ] [Vhe Editor of the Quarterly Journal is directed to make it known to the Public that the Authors alone are responsible for the facts and opinions contained in their respective Papers. | *,* The Council request that all communications intended for publication by the Society shall be clearly and legibly written on one side of the paper only, with proper references, and in all respects in fit condition for being at once placed in the Printer’s hands. Unless this is done, it will be in the discretion of the Officers to return the communication to the Author for revision, The Library at the Apartments of the Society is open every Weekday from Ten o’clock until Five, except during the fortnight commencing on the first Monday in September, when the Library is closed for the purpose of cleaning; the Library is also closed on Saturdays at One p.m. during the months of August and September. It is open until Hight p.u.on the Days of Meeting for the loan of books, and from Hight p.u, until the close of each Meeting for conversational purposes only. Vol. LXIX. JUNE 1913. No. 974. Part 2. QUARTERLY JOURNAL GEOLOGICAL SOCIETY. EDITED BY THE ASSISTANT-SECRETARY. [ With Nineteen Plates, illustrating Papers by Mr. C. T. Trech- mann, Mr. Hamshaw Thomas, Mr. R. H. Goode, Mr. E. B. Bailey, Dr. A. M. Davies & Mr. J. Pringle, Mr. J. B. Scrivenor, and Mr. R. W. Hooley. | LONDON: LONGMANS, GREEN, AND CO. PARIS:—OHARLES KLINCKSIECK, 11 RUE DE LILLE. SOLD ALSO AT THE APARTMENTS OF THE SOCIETY. Price Five Shillings. wee [Issued July 29th, 1913. ] LIST OF THE OFFICERS AND COUNCIL OF THE GEOLOGICAL SOCIETY OF LONDON. Elected 1 February ry 21st, 19138. Prestvent. Aubrey Strahan, Sc.D., F.B.S. GicesPrestdents. Prof. Edmund Johnston Garwood, M.A. Richard Dixon Oldham, F.R.S. Clement Reid, F.R.S., F.L.S8. Prof. W. W. Watts, LL.D., Se.D., F.B.S. Secretaries. Arthur Smith Woodward, LL.D., F.R.S. Foreign Secretary. Sir Archibald Geikie,K.C.B.,D.0.L.,LL.D., 8c.D., Pres.R.8. | Herbert Henry Thomas, M.A., B.Se. Greagurer. | Bedford McNeill, Assoc. R.S.M. COUNCIL. Henry A. Allen. Henry Howe Bemrose, J.P., Sc.D. Prof. Thomas George Bonney, Sc.D., LL.D., E.R.S. James Vincent Elsden, D.Sc. John William Evans, D.Se., LL.B. William George Fearnsides, M.A. Prof. Edmund Johnston Garwood, M.A. Sir Archibald Geikie, K.0.B.,D.C.L., LL.D., Se.D., Pres.R.8. Prof. Owen Thomas Jones, M.A., D.Sc. Herbert Lapworth, D.Sc., M.Inst.C.H. Bedford MeNeill, Assoc.R.S.M. Horace Wollaston Monckton, Treas.L.S. Edwin Tully Newton, F.R.S8. Richard Dixon Oldham, F.R.S. George Thurland Prior, M.A. , D.Sc., FBS. Clement Reid, F.R.S., F.L. S. Aubrey Strahan, Se. Ds EBS. Herbert Henry Thomas, M.A., B.Sc. Arthur Vaughan, M.A., D.Se. Prof. William Whitehead Watts, LL.D., Se.D., M.Sc., F.RB.S. William Whitaker, B.A., F.R.S. The Rey. Henry Hoyte Winwood, M.A. Arthur Smith Woodward, LL.D., F.RB.S., E.L.S. Asststant-Pecretarp, Clerk, and Librarian. L. L. Belinfante, M.Sc. Assistant-Librartan. Assistant-Clerk, C. P. Chatwin. M. St. John Hope. Assistant tn @ffice anv Library. Arthur Greig. STANDING PUBLICATION COMMITTEE. Dr. A. Strahan, President. Dr. A. Smith Woodward, Mr. Herbert H. Thomas, Mr. H. A. Allen. Dr. J. V. Elsden. Myr. W. G. Fearnsides. Dr. G. J. Hinde. Dr. H. Lapworth. | Secretaries. Mr. H. W. Monckton. Mr. E. T. Newton. Dr. G. T. Prior. Mr. Clement Reid. Dr. A. Vaughan. Mr. Bedford McNeill. Prof. W. W. Waits. EVENING MEETINGS OF THE GEOLOGICAL SOCIETY TO BE HELD AT BURLINGTON HOUSE. Session 1913-1914. 1913. Wednesday, November ................0+ 5*—19* be December .............000¢ 3 —l7* 1914 Wednesday, January ..............00000+ 7*—21* 39 February (Anniwersary, Friday, Feb. 20th)...... 4*_25* B Mra chy yo Ris hee eee ee uaes 11 —25* 3 Apri eerie ne eres 8 —29* % ITER Abenoohnans4o0do30905005 13 —27* SIUvOKE) asd 485655 gedsnabases 10 —24* lever will commence at Hight o’ Clock precisely. | The asterisks denote the dates on which the Council will meet. Vol. 69.] THE HUMAN SKULL, BIC. FROM PILTDOWN. 151 -which would one day be dated with precision. Successive dis- coyeries justified the adoption of the French classification ; and it was idle to decry or ignore the types and terminology that made European archeologists mutually intelligible, and in fact constituted the grammar of prehistory. Mr. E. T. Newron called attention to the highly-mineralized condition of the specimens, which seemed to point to their being of Pliocene rather than of Pleistocene age. The Prestpenr (Dr. A. Srrawan) regretted that, owing to the lateness of the hour, it had become necessary to close this inter- esting discussion, and called upon the Authors to reply to the points that had been raised. Mr. Dawson thanked the Fellows for their kind reception of his paper and for their interesting discussion. He was quite prepared, from an anthropological point of view, to accept an earlier date for the origin of the human remains, and Dr. Woodward and he had perhaps erred on the side of caution in placing the date as early Pleistocene. However, the stratigraphical aspect of the occurrence, as a! present understood, compelled them to suggest the comparatively Jater date for the human remains. The occurrence of certain Pliocene specimens in a considerably rolled condition, while the human remains bore little traces of rolling, suggested a difference as to age, but not to the extent of excluding the possibility of their being coeval. The rolled specimens might have entered the stream farther up the river than the human remains, and thus might have drifted into the hole or pocket, in the river-bed, where they were found, during the same age but in different condition. Then, again, the skull might have been surrounded by some colloid material which preserved it in its passage from some earlier deposit. It must be admitted that any attempt to fix an exact geological date for specimens found in a gravel-bed is fraught with difficulties. ‘He expressed his thanks to Mr. 8. A. Woodhead for his anal SeS ; to Dr. Edgar Willett for kind assistance in tracing the gravel ; and to Mr. Ruskin Butterfield and Mr. A. W. Pigott on the loan of implements found at Fairlight. In conclusion, Mr. Dawson expressed his intention of offering the specimens as a gift to the Trustees of the British Museum. Dr. Samira Woopwarp admitted that the restoration of the symphysial end of the mandible exhibited was a bold experiment, but he failed at present to conceive of any other interpretation of the fossil. Remembering the failure of Mrs. Selenka’s great excavations in Java where Pithecanthropus was discovered, he did. not anticipate certain success in future work at Piltdown, but he hoped to take part in further diggings. He did not think that the differences between the Heidelberg and the Piltdown mandibles necessarily implied differences of geological age. The swamps and forests of the Weald in early Pleistocene times may have been a refuge for a backward race. Q.J3.G.8. No. 274. M r 152 MR. 8. S. BUCKMAN ON [June 1913, 9. The ‘ Kuttoway Rock’ of ScarporoveH.’ By 8. 8. Buckman, F.G.S. (Read March 5th, 1913.) ConTEntTs. Page ihe wvockranduitseAmmioniteshaunaeeeeeeeeeeeeeseeseenes 152 Il. Remarks on the Fauna and the Zones ..............2.-- 156 NOL, 1blescmicolloeiieall Tera TANS .50>0001099s00000n000000000000000005 162 IV. On Development and Homceomorphy .................. 165 I. Tue Rock anv rvs Ammonites Fauna. Over fifty years ago an important paper on ‘ The Kelloway Rock of the Yorkshire Coast’ was published by John Leckenby in this Society’s Journal.” It dealt chiefly, if not entirely, with the development of the stratum in the neighbourhood of Scarborough. From this rock he recorded over thirty species of ammonites, many of which were new. Several of these were not figured, and they may be said to have remained almost unknown to science, except perhaps locally. Even of those figured it has been difficult to determine from the descriptions and illustrations what were their generic affinities—a task not altogether easy, even when the specimens themselves are handled. It is obvious from the ammonite fauna which Leckenby described that the Kelloway Rock of Yorkshire comprises more than the Kellaways Rock of Wiltshire, that it is in part a calcareous equivalent of the Oxford Clay of the southern counties. But, at the same time, this does not state the whole of the facts: for the ammonite fauna of the Yorkshire stratum is not found, so far as many species are concerned, in the Oxford Clay of the southern counties; while certain species of the Kellaways Rock are absent fzom the Yorkshire deposit. It therefore becomes of interest to see what the ammonites are, and what zonal series they represent. By the kindness of Prof. McKenny Hughes and Mr. Woods of the Sedgwick Museum, Cambridge, all the types of the ammonites described by Leckenby which are in their possession have been sent to me for study.’ The authorities of the Museum of Practical Geology, Jermyn Street, London, have also sent to me a considerable series of Callovian-Oxfordian ammonites for determination, among them being many species from the Kelloway Rock of Yorkshire. . To all these gentlemen I beg to tender my best thanks. 1 The appellation ‘ Kelloway ’ is here used for quotations from Leckenby or in reference to Yorkshire beds, and ‘ Kellaways’ in relation to deposits in Wiltshire and elsewhere. 2 Q. J. G.S8. vol. xv (1859) p. 4. 3 The intention is to figure these types in which he thinks is the equivalent of Leckenby’s rock. At any rate, both authors find this stratum, or these strata, at the top, close under so-called ‘ Oxford Clay.’ The vertwmnus zone shows a fauna which differs considerably from any fauna found, so far as my experience goes, in the rest of Engiand. Aspidoceras faustum, Quenstedtoceras vertumnus, Q. aft. gregarium, Pachyceras rugosum, Oppelia glabella, Siemiradzhia poculum are all species which seem to be special to Yorkshire as distinct from the rest of England, leading to the inference that the Oxford Clay deposits of the Midlands and the South are incomplete. A. faustum and S. poculum are found in Normandy, where also are found species of Pachyceras allied to P. rugosum. A. fuustum is re- markable for its likeness to certain forms of Aspidoceras found in the Lower Caleareous Grit (basal Argovian) of Oxford and the neighbourhood, but that corresponds to a much higher stratum in Yorkshire. The gregarium zone also shows a fauna peculiar to Yorkshire, as compared with the rest of England. Quenstedtoceras gregarium is most like some Russian species. (@. twrgidum and Aspideceras hirsutum are found in France. It is obvious that, at present, it is not possible to say which is the higher of the two matrices and the two faunas. The sequence now indicated is a supposition; but the calling of attention to it may be the means of obtaining the required solution. It is presumed that these strata represent in a general way the marie zone of the Normandy coast, and the likeness of Quenstedtoceras vertumnus to Y. marie favours this view. But I have seen no evidence as yet for any marie fauna in the Oxford Clay of the rest of England.’ A few words may now be said about the Oxford Clay of York- shire. Fox-Strangways (op. cit. p. 295) quotes fifteen ammonites 1 Identifications of Ammonites marie cannot be accepted without investi- gation: A. d’Orbigny mixed several forms. (See below, p. 164.) Vol. 69. | THE ‘ KELLOWAY ROCK’ OF SCARBOROUGH. 159 from it, but eight of these he also gives as from the Kellaways Rock. Of the remainder, three more are of the age of the ‘ Kelloway Rock,’ as developed in Yorkshire: that is to say, Ammonites compton and A. elizabethe are species of the ornatwm zone, while A. eugenii belongs to the athleta zone. ‘This leaves only four species. Of these, two, A. cordatus and A, vertebralis, are, when correctly identified, species of the Lower Calcareous Grit as developed in the Oxford district. But in the top layer of Oxford Clay, subjacent to the Lower Calcareous Grit, is a fauna with several Cardioceras-like species, which are often in- correctly assigned to A. cordatus and A. vertebralis. Such a fauna, which must be worked out another time, may be indicated by the citation of these species from the Oxford Clay of Yorkshire.’ There remain now only two species, A. vernoni* and A. oculatus.’ By the kindness of the authorities of the York Museum, which 1 gratefully acknowledge, the types of these two species have been placed in my hands for study. So far as I know, they are quite peculiar to Yorkshire. They may have lived contemporaneously with the Cardioceras-like species, or they may indicate another date.* It will not commit us, then, irretrievably to mark the Oxford Clay of Yorkshire, which is not contemporaneous with the ‘ Kelloway Rock,’ as being of vernont hemera, until the facts can be more accurately ascertained. There is yet another species from the Oxford Clay of Yorkshire, Peltoceras intertewtum Simpson sp.’ incorrectly assigned to the Lias by its author. But it is a derived fossil and is pyritized, and is, moreover, an Oxford Clay form. It is probably from the athleta zone, Where that zone is argillaceous and not calcareous. My thanks are due to the late Mr. T. Newbitt, F.G.S., and the authorities of the Whitby Museum for kindly allowing me to have the type for study. The results of the foregoing remarks may be stated graphically as follows (Table IV, p. 160) :— 1A flat (?thin) form of the so-called ‘Am. cordatus’ is presumably Am. scarburgensis Young & Bird, which is thus described (‘Geol. Surv. Yorkshire Coast’ 2nd ed. 1828, p. 265):—‘ We have a small ammonite re- sembling this [d. speetonensis Bean] on the side, but very flat, and with a crenated keel, found by Mr. Williamson in the second shale [Oxford Clay | at Scarborough. ‘This species may be named A. scarburgensis.’ 2 «Geol. Surv. Yorkshire Coast’ 2nd ed. (1828) pl. xiv, fig. 5. 3 J. Phillips, ‘Geol, Yorkshire’ vol. i (1829) p. 138 & pl. v, fig. 16. + In certain MS. lists of Jurassic zones which I drew up for the Geological Survey, I used the term ‘ pre-cordatus’ for these Cardioceras strata of the Oxford Clay which underlie the Caleareous Grit where C. cordatwm occurs. This provisional term was necessary, because there are no correctly identified ammonites to give a name. 5 * Fossils of the Yorkshire Lias’ 1855, p, 50. DIvVESIAN. CALLOVIAN. 160 MR. S. S. BUCKMAN ON [June 1913, Tapre IV. Time-TABLE AND COMPARISON OF CALLOVIAN-DIVESIAN (OXFORDIAN) DEPOSITS. Hemere. Strata. Remarks. Yorkshire. Midlands, etc. ( vernoni ...... Oxford Clay. a) ) sed) a | 2) a SS | Sef 8 | gregarium | fs} | x ) SD Oe 9 I. = BE La es Ee r Neacvidene . Marie Zone of J f 2EC lS f= “a demas ° Normandy Coast. | vertumnus... | Ba &|2SSoS ‘ | S S S Oc ae 1 JO" eS om) y) ee A trace of the 7 BEKLE ibe: fauna. | Well developed in VWs | es en Buckinghamshire | lamberti ...... fees Sar oe || Upper Oxford Clay. ce BYR ae (S288 5 athleta ...... rp Se beeee | = Athleta Zone, Oxford. Late 7 | Se | 86 Ss | = Perhaps incomplete. | development ornatum ...... | S | Zee 2 || © Clay with Cosmoceras, Middle | Wie Los PWahy ode Oxford. ce dee coronatum | Neither fauna | S Reginaldi Bed, Early | Cosmoceras. (nor deposit J z Trowbridge. 5 found. A < anceps ...... J Trace of fauna in D ene = 7a eposit with good ne ne MS its: Reineckeia fauna, Sa cae Isle of Mull, Hebrides. removed. calloviense... Fauna and deposit ) Kellaways Rock. may be present. | Kellaweave H. B. Woodward. \ keenigi......... Kelloway Rock | Hels Kellaways Clay. (Leckenby). J H. B. Woodward. The foregoing Table shows that the ‘ Kelloway Rock’ of York- shire is, in the main, contemporaneous with the Oxford Clay of the Midlands and the South of England, and is therefore later than the Kellaways Rock of these parts. It also shows that, according to the evidence of the Oxford-Clay fossils of Yorkshire cited by Fox-Strangways,' the ‘Kelloway Rock’ of Yorkshire is 1 The following table shows the zones which the ammonite species cited by Fox-Strangways from the Oxford Clay of Yorkshire may be presumed to indicate; some records have been interpreted :— Taste V.—‘'Oxrorp Cuay’ AmMonirE ZONES. MERMONU taeeecee A, vernoni, A. oculatus (A. cordatus, A. vertebralis= Cardioceras spp. may be higher). GEGUTIUM ...4.. A. perarmatus=Aspidoceras hirsutum Bayle. VETTUMNUS ...... A, marie=A. vertumnus. TENGGETL .....-..- A, crenatus= Creniceras sp. lamberti ........- A, lamberti. Gthbeta. eee. .2e A, binatus, A. eugenii. CPMGOED, ercooccor A, elizabethe, A. compton. There is also A. crenularis Phillips, ‘Geol. Yorks.’ vol. i (1829) pl. xii, fig. 22, probably a Quenstedtoceras, and presumably from the lamberti zone. Vol. 69.] THE ‘ KELLOWAY ROCK’ OF SCARBOROUGH. 161 only developed locally so far as certain of its beds are concerned, and that even within the county itself it passes laterally into, and 1s contemporaneous with, the Oxford Clay. The idea that the Kellaways Rock and the Oxford Clay were always and wholly sequential deposits, carried out in our literature and in the museum arrangement of specimens,’ where the same species are found in a lower case headed ‘ Kellaways Rock’ and in a higher case labelled ‘Oxford Clay,’ is one which must be abandoned. ‘These stratigraphical terms are misleading: they do not indicate sequential deposits, but beds which were in the main contemporaneous. All that they indicate is the lateral change from arenaceous or calcareous to argillaceous conditions. It is suggested that for the earlier deposits the term ‘ Callovian’ be retained; the Callovian will then roughly coincide with the development of the genus Cosmoceras and its allies Aepplerites and Sigaloceras. For the later deposits the term ‘ Divesian’ (Dives, Calvados) has been suggested to me by Prof. Welsch; it marks the development of Quenstedtoceras. When Quenstedtoceras is replaced bv Cardioceras (Lower Calcareous Grit, Coral Rag, and, perhaps in some cases, highest layer of Oxford Clay) the term should be ‘ Argovian’ for Cardioceras-yielding strata following Diyesian. These terms would be uniform; but the terms ‘ Oxford Clay, ‘Kellaways Rock,’ ete., are useful, if it be remembered that they vary in value in different localities. lt is inadvisable to use ‘Oxfordian’ for Divesian, because in Continental usage ‘ Oxfordian’ stands mainly for Argovian (Oxford Oolites). The suggestion illustrated in Table IV is that the Callovian- Divesian deposits are locally incomplete ; that the deposits of certain hemerz have been locally removed by penecontemporaneous erosion, as is usual with deposits of the Bajocian, Aalenian, etc.; that a full sequence of deposits can only be obtained by placing together the developments of many localities ; and that, to express the entire sequence, a full table of zonal or hemeral names, such as is now given, is necessary. The object of a full table of hemeral names is to obtain a true record of the sequence of ammonite faunas as a necessary prelude to a study of their development. A theory of unrepresented zones may explain in part why the ammonite fauna of certain beds is so peculiar to Yorkshire; but in other cases, where zones are represented, and yet there is distinctive peculiarity, that explanation fails. It may then be necessary to 1 Such statements have given much trouble: see J. F. Pompeckj, ‘Jur. Fauna of Cape Flora’ Norwegian North Polar Exped. vol. i (1900) No. 2, p- 120. The Professor rightly judges that ‘the Kellaways Rock and the Oxford Clay [of English geologists] may be petrographically different facies of faunistically corresponding strata’; but then he adds, ‘and in both the Kellaways Rock (especially that of Yorkshire) and the Oxford Clay, the different zones of the Callovian, as they may be observed on the Continent, cannot be separated.’ That statement is disputable : the Yorkshire specimens, from their different matrices, are easily separable into zones in the study, and that must be possible in the field. 162 MR. S. S. BUCKMAN ON [June 1913, suppose that at times there was not free communication between the districts north and those south of the Humber. It is now for the Yorkshire geologists, or those who have the opportunity to work the Yorkshire cliffs, to ascertain how far the facts in the field agree with this armchair stratigraphy. Here, at any rate, are the suggested points for consideration ; and, if only building operations or slips of Boulder Clay have not concealed the important beds, observation of the zonal sequence should not be difficult. Further facts will be welcome, whether they confirm or contradict the present suggestions. The object is to call attention to the knowledge required, and to put forward something which may be a working hypothesis—something which may stimulate the attainment of further knowledge. Examinations of old collections may be useful, but it must be remembered that the labels of localities in collections are not to be trusted. Yorkshire and Wiltshire specimens have been mixed, and specimens from the Scarborough Limestone (Bajocian) and Scar- borough ‘ Kelloway Rock’ have been interchanged. But they can all be separated by examination of matrices: the matrix is really the most trustworthy label that a fossil possesses. ILI. PatmonrorogicaL Remarks. AMMONITES ORDINARIUS Bean-Leckenby (Leckenby, p. 8). I have reason to think that this is not a ‘Kelloway Rock’ species, but is from the Calcareous Grit, and has been wrongly placed and perhaps wrongly localized. If so, it is a Cardioceras more or less nearly identical with Am. goliathus d’Orbigny (pl. exevi, figs. 1 & 2 only), and it may be a synonym of Nautilus ammonoides Young & Bird.' CapocERASs GREWINGKI Pompeckj.* This species is hardly a true Cadoceras, but it belongs to a series which in form and appearance is intermediate between Cadoceras and Quenstedtoceras. ‘This species and its allies occur in the Kellaways Rock of Kellaways, and have. been placed sometimes as Ammonites marie WOrbigny. The ‘Russian variety ’ which he figures by that name® belongs to the grewingki series, but the other examples are quite distinct (see Q. marie, p. 164). CaDocERAs, sp. nov. Some of Bean’s examples of Am, Jongevus belong here as a much compressed ally of C. grewingkz. The form is also near to Quenstedtoceras primigenium Parona & Bonarelli.* CapocrRAs susLmvE J. Sowerby sp. By this name is intended the small form figured in the lower right-hand corner of Sowerby’s 1 Geol. Surv. Yorks. Coast’ 2nd ed. (1828) p. 271. 2 ‘ Jura-Fossilien aus Alaska’ Verkandl. K. Russ. Mineral. Gesellsch. ser. 2, vol. xxxviii (1900) pl. vi, figs. 1-3. 3 «Terr. jurassiques : Céphalopodes’ 1842-49, pl. elxxix, figs. 7 & 8 only. ‘Call. inf. Savoie’ Mém. Acad. Savoie, ser. 4, vol. vi (1895) pl. 11, fig. 4. cS Nols 6G. THE ‘ KELLOWAY ROCK’ OF SCARBOROUGH. ; 163 plate (‘ Min. Conch,’ vol. i, 1812, pl. liv), leaving the more globular form as a matter of convenience under the name C. modiolare Lhywd-dOrbigny sp., of which A. d’Orbigny’s figure would be the type. From Gristhorpe Bay I have a fragment of C. subleve as above defined.’ It is from a matrix of loose sand, suggesting Leckenby’s bed B, but he says that this is unfossiliferous. C. subleeve (+ modiolare) would appear to be easily identifiable ; but in one case it has been very much misunderstood (see below, Pachyceras robustwin). Pacuyceras RucosuM. Bean’s Aimimonites rugosus is a species of the rare genus Pachyceras, differing sufficiently trom A. lalandeanus d@Orbigny. I cannot recall any other record of an English species of the genus, PACHYCERAS ROBUSTUM, nom. noy. This is founded on Stephano- ceras subleve, K. K.-Deslongchamps, ‘ Foss. Oxford. Coll. Jarry ; Notes Paléontologiques,’ vol. 11 (1889) pl. i, figs. 2-4, taking fig. 4 as the type. Prof. Pompeckj* has noticed that the species is not identical with Sowerby’s Am. sublevis, but he has failed to see that itis not a Cadoceras, for he has definitely assigned it to that genus. However, the straight massive ribs and the nodose ornament strong on the umbilical border show that it is not a Cadoceras : it belongs to the genus Pachyceras, and like this genus but unlike Cadoceras it becomes less inflated with age. P. robustum is near to P. rugosum, but has more pronounced ornament and strong umbilical nodosities, of which P. rugoswin shows only traces. P. rugosun is also thinner. The position of P. robustuwm, lamberti beds of Villers-sur-Mer (= lamberti- gregarium zones, perhaps, of this paper), is correct for a Pachy- ceras, but is incorrect for a Cadoceras—a genus which belongs to the Lower Callovian. P.vobustum shows that the genus Pachyceras is an offshoot of the genus Hrymmnoceras: the study of P. rugosum had already led me to form the same conclusion. P. robustum, P. rugosum, P. lalandeanum form in this order a good catagenetic series, in which ornament and thickness are decreasing. The identification of P. robustum with Ammonites sublevis and as a Cadoceras is good testimony to the deceptiveness of homceomorphy in certain cases, and the likeness thus testified to is an example of a rather unusual form of homceomorphy (see § IV, ‘On Development & Homeomorphy’ p. 165). PELTOCERAS MURRAYANUM. ‘There must be some error in Simpson’s description given by Leckenby (op. cit. p.10). To describe a species of this genus as 12 inches in diameter but only three- quarters of an inch thick, must be incorrect; yet the description 1 «Terrains jurassiques : Céphalopodes ’ 1842-49, pl. clxx. + «Jurassic Fauna of Cape Flora’ Norw. North Polar Exped. vol. i (1900) No. 2, p. 79. 164 MR. S. S. BUCKMAN ON [June 1913, obviously refers to a Peltoceras. I have received from the Whitby Museum a specimen supposed to be the type. It is rather more than 2 inches in diameter, and is then three-quarters of an inch thick; but it does not altogether agree with the description. Further search for any specimen so named by Simpson may be requested of those who haye charge of old collections of Scarborough fossils. Prrrocrras suBrEeNsr. Leckenby identified this doubtfully with Ammonites arduennensis dOrbigny, but it is not that species. The regular radial (versiradiate) costee, which bifurcate about the middle of the lateral area, distinguish it from d’Orbigny’s species. The position of furcation distinguishes it from many other species. It is a much compressed form, carrying the costate stage a long time, and hardly attaining to the bituberculate stage. The largest example is 176 mim. in diameter. PHLYCTICERAS HYPERBOLICUM. Simpson’s Ammonites hyperbolicus is a most remarkable and interesting species. It is the senile development of the genus Phlycticeras,* which, so far as I recollect, has not yet had any of its species recorded from England. It has lost nearly all ornament, though there remain just sufficient traces of rib-contour to indicate the generic association. The keel has been reduced to a mere ridge. Such a senile species of the genus — has not, so far as | know, been recorded. QUENSTEDTOCERAS GREGARIUM., This species has as a distinctive feature ribs much forwardly inclined across the whorl (prorsi- radiation). A Russian species, Amaltheus leachi Nikitin” (non Sowerby), has the same style of tangential ribbing—as if the periphery had been turned forwards around the centre; and it has much the same proportions. Another Russian species, Amaltheus rybinskianus Nikitin,’ is what one would expect as the involute stouter-whorled development. I have not seen such tangentially ribbed forms from any other English localities where other Quen- stedtocerata abound. QUENSTEDTOCERAS LonG@vumM. Leckenby’s placing of this as a synonym of Ammonites lamberti Sowerby was not correct. The Bean types show two species belonging to two different stocks, one is near to @. placenta (see below) and the other belongs to the Cadoceras-grewingki series (see Cadoceras, sp. nov., p. 162). QUENSTEDTOCERAS MARIZ. D’Orbigny (‘Terr. jurassiques: Cépha- -lopodes’ pl. clxxix) has several forms under this name. It is 1 Phlycticeras Hyatt=Lophoceras Parona & Bonarelli. For a treatise on the species see their work, ‘Call. inf. Savoie’ Mém. Acad. Savoie, ser. 4, vol. vi (1895) p. 90. 2«Die Jura-Ablagerungen zwischen Rybinsk, &e.’ Mém. Acad. Imp. St. Pétersb. ser. 7, vol. xxviii (1881) No. 5, pl. i, fig. 5. > Id. pl. i, fig. 8. Vol. 69. ] THE ‘ KELLOWAY ROCK’ OF SCARBOROUGH. 165 advisable to fix one as the type, and for this the example depicted in his figs. 5 & 6 is selected. I understand that this occurs high in the Divesian ; but it is doubtful whether we have it in England. The Russian variety (figs. 7 & 8) has nothing to do with it, and probably occurs low in the Callovian. See Cadoceras grewingki (p. 162). QUENSTEDTOCERAS PLACENTA. ‘This very involute species is not a true Quenstedtoceras, but still less is it a Cadoceras of the grewinghi series. It would seem to be peculiar to Yorkshire. QUENSTEDTOCERAS TURGIDUM. This is a senile form, like the example which A. d’Orbigny has ascribed to Ammonites lamberti (‘Terrains jurassiques : Céphalopodes ” pl. elxxvii only), but with a more trigonal whorl, and the venter is more acute in the costate stage. QUENSTEDTOCERAS VERTUMNUS. ‘This is a species with stout ribs, which look like pieces of cord wound round the whorl. I have not seen it from any other locality. Dr. Pompeckj rightly associates it with Q. marie d@Orbigny sp., but it is not ‘a modification of a Quenstedtoceras marie d’Orb. sp. with a wider umbilicus’:! rather is Y. marie the involute inflated development of Q. vertumnus.” LY. On Devetopment anp HomamomorpHy. There is an interesting repetition in development, leading to homceomorphy, in many of the Middle Jurassic ammonites. They pass repeatedly and independently from evolute compressed to involute inflated, in some cases to sphwrocones, a phenomenon which may be observed in the Callovian genera Cadoceras, Phlycti- ceras, in the Divesian Quenstedtoceras, and in the Argovian Cardio- ceras. (A similar line is followed by the Kimmeridgian Ameboceras, but is not carried so far.) The same phenomenon is also repeated again and again in the different stocks of these various genera quite independently. This phenomenon has caused much confusion in the identification of the various species, and has led to much ‘lumping,’ because it was not understood. And the ‘lumping,’ or the failure to recognize what were the critical points of distinction, underlying the likeness, has caused stratigraphical lists to be in- valid, and has also given a wholly false range to some much-quoted species, thereby impairing stratigraphical correlation. And that the likeness, the homceomorphy, should have caused the ‘ lumping is the best testimony to its completeness. The likeness is often the greater when, as is so frequently the case, the loss, or nearly so, of the principal distinctive characters (ornament, keel, etc.) has accompanied the inflation. Other genera not dissimilar in time and in appearance, Macro- cephalites, Lrymnoceras, Pachyceras, develop in a different direction— 1 J. F. Pompeckj, ‘Jurassic Fauna of Cape Flora’: Norw. North Polar Exped. vol. i (1900) No. 2, p. 97. 2 See §1V, ‘On Development & Homceomorphy.’ 166 MR. S. S. BUCKMAN ON [June 1913, as they become involute and more aged * they lose inflation, and by this criterion they may be distinguished from the preceding series of genera. Now, when one series is travelling from thin to thick and another from thick to thin, there is every possibility of their reaching a median collision-point, thus :— Thin Thick K fi Thin Thick At the median point, given certain factors, there would be homeomorphy: not the homceomorphy of subparallel lines of de- velopment as in the first-quoted genera, but the more interesting— and, by the nature of the case rarer—phenomenon of homceomorphy of crossing lines of development. ‘The very interesting case of Pachyceras robustum and Cadoceras subleeve mentioned above (p. 163) is an example, and a very good example, of such homceomorphy. It caused incorrect identification and, in consequence, an un- warranted extension of the zonal range of Cadoceras. Homeomorphy of the first kind may be called parallel homcomorphy, that of the second transversal homeo- morphy: these terms refer to the manner in which the pheno- menon was produced. Isochronous and heterochronous homeomorphy state whether the homceomorphous species hved in the same or at different times. There is yet another mode of producing homceomorphy, and this may be called cyclical homcomorphy. It arises when a species in the course of its development retraces its tracks: that is to say, when a species showing a catagenetic stage apes one in an anagenetic stage. For example, an anagenetic species is in the pre-tuberculate costate stage, the catagenetic species is in the post-tuberculate cestate stage. The position may be illustrated diagrammatically thus :— tuberculate The circles represent the main stages of the two species which 1 There would be renewed evolution (outcoiling) in extreme old age (incipient scaphiticone stage). Vol. 69.] THE ‘ KELLOWAY ROCK’ OF SCARBOROUGH, 167 look like enough to be confused (are homceomorphous) until they are analysed ontogenetically, which is not always done, Such a heterochronous case, partly concerned with species dealt with in the present paper, is not of the most striking kind, but it deserves mention ; it is the case of the young costate Peltoceras, like enough to Dactylioceras of the communis type to cause the former to be sometimes labelled as the latter and relegated to the Lias. Now the former is anagenetic (renewed anagenetic, perhaps), it is in the pre-tuberculate costate stage; the latter is catagenetic, it is in the post-tuberculate costate stage. By attention to the various phases of homceomorphy the apparent tangle of ammonite species and the apparent anomalies of strati- graphical records are found to come into definite order. Then it is seen that the many names for genera and species are insuflicient to express the facts, and that more names will give a clearer picture of the lines of evolution—that they are a real help to the memory, and not a hindrance. Discussion. Mr. J. W. Starner remarked that the beds from which the old collections were obtained are now inaccessible, being covered by buildings at Scarborough and by landslips at Gristhorpe. These fossiliferous beds occur in the uppermost part of the Kellaways Rock, the remainder of the formation being practically unfossil- iferous. He mentioned that the best opportunity for obtaining Kellaways fossils in Yorkshire, during recent years, was in the cutting on the Hull & Barnsley Railway at South Cave, and he hoped that the Author would examine the collections made by the local geologists from that locality. Mr. I. F. Spars congratulated the Author on his most in- teresting paper and the Society on receiving that valuable paleon- tological contribution. When he thought of the state of hopeless confusion in which Hyatt had left the classification of these Callovian (as, indeed, of all other) ammonites, putting such closely allied genera as, for example, Stgaloceras and Kepplerites or Erymnoceras and Reineckeia, not only into different families, but different super-families, and when he remembered the misdoings of the French school, who at the present day included in the Oxfordian genus Pachyceras, so ably traced by the Author that evening, even certain Portlandian holcostephanoids, he felt that all paleontologists must look forward to a study of the details of this paper with the greatest interest. A point to which he desired to draw attention was the use of the terms Callovian and Oxfordian. ‘here was hardly a strati- graphical term which was employed less definitely and less satis- factorily at the present day than those terms Callovian and Oxfordian, not only on the Continent, but also in this country. In one great London museum, for example, even Kimmeridge-Clay ammonites were labelled ‘Oxfordian.’ In the speaker’s opinion Q.J.G.8. No. 274. N 168 THE ‘ KELLOWAY ROCK ’ OF SCARBOROUGH. [June 1913, the Society was greatly indebted to the Author for his table of zones, which indicated how the terms Callovian and Oxfordian, or preferably Divesian, might profitably be employed. His classi- fication was not the orthodox one, but it rested on a sound palseontological basis. Dr. A. M. Davies said that those geologists who were interested in the Upper Jurassic strata should rejoice in the knowledge that the Author was turning his attention to the zoning of those rocks. It was certain that the number of Upper Jurassic zones would have to be increased. The Prustpen'r (Dr. A. Srranay) reminded the meeting that the relations of the Kellaways Rock of Yorkshire to the Oxford Clay, and the fact that it was not strictly correlative with the Kellaways Rock of Wiltshire, had been pointed out by the late Mr. Hudleston many years ago. He enquired whether it was contemplated that the misspelling ‘Kelloway’ could or ought to be perpetuated. The phenomena described under the names of cyclical and trans- versal homceomorphy appeared to be of great interest and to deserve close scrutiny. The Avrnor, in reply, remarked that the spelling ‘Kelloway Rock’ was not his, and he had merely adopted a suggestion made, he believed in the first place, by the late Mr. Hudleston, to keep ‘Kelloway Rock’ for the Yorkshire bed and ‘Kellaways Rock’ for the more limited Wiltshire stratum, as a temporary measure. In conclusion, he heartily thanked the Fellows for their kind reception of his paper. Vol. 69.] DERIVED CEPHALOPODA OF THE HOLDERNESS DRIFT. 169 10. The Dertven Cermaxopopa of the Hoxtpprness Deirr. By Cuartes THompson, B.Sc. (Communicated by G. W. Lampiven, F.R.S., F.G.S. Read January 22nd, 1913.) ConTEnts. Pag Mi ROCICHIOM ee ctncaesncec cardia ssveatnetesdeljutenndcaess ee 169 IL. The Liassic Ammonites, ete. from the Drift, and Live um Vila RICO smart cracls aeweaa rales doeloecieiseeed stone + 170 III. Oolitic and Kimeridgian Cephalopoda from the ND ea titi ciaececreneatyeesiicch as wit wateiacc late ceewmetuinse sen st bed sie 177 IV. Lower Cretaceous Cephalopoda .................2.0. 00 177 V. Upper Cretaceous Cephalopoda .......................- 178 Wil, tomhaimenay ayael Clonmel svn) sodocosea conve asevsocosdnare son. 178 VII. Lists of Derived Cephalopoda found in the Glacial ID eis Or 1a lols eyane ss) Coeqcocuedeesconosessuedernebecna -euceor 180 I. Inrropvuctrion. For a long time it has been common knowledge among geologists that the Drift of Holderness, and of the Yorkshire coast generally, yields specimens of Jurassic cephalopoda, and at one time these specimens were assiduously collected. Karly in the last century, Phillips, in his classic ‘ Illustrations of the Geology of Yorkshire,’! stated that fully three-tourths of the then known species of the fossils of the Lias could be found in the ‘ Diluvyium.’ Again, Simpson and J. F. Blake, in their respective writings, mention certain fossils as being more abundant in the Drift of Holderness than in the known expo- sures of the Lias. Since those authors wrote, the remanié fossils have been ignored until recently. There are now, however, two large col- lections of ammonites from the Boulder-Clay cliffs themselves, and also from the beach-stones derived presumably from the same clay. The one has been made by Mr. William Morfitt of Atwick, the other by myself and my colleague, Mr. A. H. Denham, of Hymers College, Hull. These two collections, along with other smaller ones, show that Phillips almost certainly understated the proportion of known forms obtainable from the Drift. It is more probable that prac- tically every species of the multitorm Liassic ammonites known from Yorkshire exposures has also been found, or can be found, in the Drift. Beside this stands the important fact that in the clay itself and in the beach-stones there have now been found many fossil cephalo- pods which, so far, have never been obtained, or at least recorded as . obtained, in situ in the Yorkshire Lias. The Oolitic and Cretaceous forms are, however, less fully represented, though the Speeton 1 «Pt. 1—the Yorkshire Coast’ 1829, pp. 176-77. N2 170 MR. C. THOMPSON ON THE [June 1913, Clays (Lower Cretaceous) have yielded abundant material to the Glacial ice, so that Mr. Morfitt has been able to gather a beautiful set of those remarkable globose forms which distinguish the Valanginian fauna, and are so rarely found in place at Speeton. A point of much importance in connexion with these fossils from the Drift is that, when one examines the matrices of many of them, it is seen that the rock cannot be now matched within the borders of our county, and the pertinent question arises: Whence have they been transported ? I dealt briefly with the subject in a preliminary note and list published in the Transactions of the Hull Geological Society for 1910; but in the present paper I propose to offer a more compre- hensive and up-to-date account, in which are included the results of my later researches and of my examination of all available specimens in the possession of other coliectors and in the various museums. The net result is that the previous list of ammonites has been more than doubled in these last two years. II, Tue Lrasstc AMMoNITES, ETC. FROM THE DRIFT, AND THEIR Marrices. Planorbis aud lower (?) Beds. Taking species in their recognized stratigraphical order, the first on the list is Psiloceras (?) hagenowt (Dunker, Quenst.). My colleague obtained several specimens from a block of very fine- grained, hard, splintery, ferruginous limestone. These specimens were the first representatives of the species to be recognized from an English source. Mr. Buckman confirmed my determination, and has since found two specimens in the Tate & Blake Collection at the Museum of Practical Geology, Jermyn Street. This species is a remarkable one, for it has well-defined ceratite suture-lines, with smooth rounded saddles and but slightly corrugated lobes. The rock may actually be a relic of the marine Trias, or may be from some passage-bed not developed, or at any rate not yet found, on land in this country. The species occurs on the Continent in Northern Germany, Bohemia, the North-Eastern Alps, and Switzer- land. So recently as last August another fragment of this species was seen on the face of a block of the same kind of limestone, several miles from the place where the first was found. There is no matrix known at present in the English Trias, or in the Yorkshire Lowest Lias, resembling this. Most of the English lists, if not all, give two species of ammo- nites only—Psiloceras planorbis and Caloceras johnstoni—as being found in the Planorbis Zone. This restriction is remarkable, for in all the other zones of the Lias there are many representative species of the ammonite race. That it is not true of the beds of this zone laid under contribu- tion by the ice-sheet is shown by the fact that, from the many Vol. 69.] DERIVED CEPHALOPODA OF THE HOLDERNESS DRIFT. aie derivative specimens of Pszloceras submitted to Mr. Buckman, he has identified the following :— Psiloceras cf. brevicellatum Pompeck}. | Psiloceras cf. plicatum (Quenst.). Ps. erugatum (Bean-Phillips). | Ps. provinciale ? (Quenst.). Ps. erugatwm ? (Bean-Phillips). Ps. cf. psilonotum (Quenst.). Ps. cf. deve (Quenst.). | Psiloceras sp. nov. This list implies that there is much careful work still to be done on this genus, and that English lists will receive some addition to their scanty tale of two. It is of interest to observe that Psiloceras provinciale (?) and the new species are very similar to several figured by Dr. F. Wiihner ' and recorded as occurring in a yellowish- grey limestone, together with Wehneroceras ineyastoma, at Schreinbach. They are, therefore, of a later age than Ps. planorbis itself. Our specimens differ in having somewhat less complicated suture-lines. The Schreinbach forms possess very much foliated suture-lines, and the whorls are more inflated. In our own collection there are more examples of Ps. eruqatum than of any other form. Other collectors, however, possess more specimens of the Ps. leve type, which I believe are very similar to, it nob identical with, the German type styled Ps. lave. The matrix of the specimens is generally a crystalline shelly limestone, but in a few cases a tough fine-grained earthy one. The colour of the rock is usually pale grey, sometimes it has a brownish tinge. As in Tate & Blake’s time, so now, there is no locality in Yorkshire where these limestones can be seen in place. It is evident from the character of these lowest limestones that, although they do not indicate a deep sea, they do indicate a clear one, free, or nearly free, from the dark mud of the succeeding zones, This may indicate either remoteness {rom the coast-line of the time, or the absence of mud-bearing currents. Caloceras Beds. On the Continent, between the Planorbis Zone and that of Schlotheimra angulata, there is a so-called ‘Caloceras Bed,’ but this bed has never yet been identified in Yorkshire. In the Drift, however, many specimens are found of the genus Caloceras with fairly stout whorls, which may at present be collected under the specific names of C. johnston: (Sow.) and C. belcheri (Simpson). The specimens of this series (with one exception) have not been submitted to Mr. Buckman; but, from the varying suture-lines and ornamentation, 1am impelled to the conclusion that there are more than two species in the Boulder Clay. Most of the specimens are beautiful casts in calcite. The matrices are all hard limestones, and no other ammonite has yet been found associated with them in the same block. As a rule, there is no other fossil visible in the boulder. 1 «Zonen des Unteren Lias’ Beitr. Pal. Gisterr.-Ung. vol. iii (1884) pl. xxiii (xi) figs. 6a & Ta Ny2 MR. C, THOMPSON ON THE [June 1913, We have not yet been able to confirm Blake’s statement? that C. johnston. is found ‘in nodules on the coast, as well as ‘on situ at Redcar,’ but it is well to bear in mind that one positive fact is worth more than any amount of negative evidence. When reviewing the very slender whorled series belonging to this genus, one finds that until this year (1912) these very slender forms have disclosed themselves by only the poorest of fragments, although search has been made for them for many years. Quite recently, however, I found a boulder containing beautifully preserved specimens, the best that I have ever seen. Mr. Buckman identifies them as follows :—Caloceras laquem (Quenst.), C. cf. laquem (Quenst.), and C. allasii (Brown). Neither Simpson nor Tate & Blake, although truly indefatig- able collectors, found these beautiful narrow-whorled forms in the north of the county. Again, as in the case of Psiloceras, work has still to be done on the English specimens of this genus. It is rather a remarkable fact that I have not found one speci- men of any of the preceding forms in the Boulder-Clay cliffs themselves. All these older forms come from the beach-stones, as if washed from a clay which is suffering submarine erosion. Angulata Beds. Dealing now with fossils from the zone of Schlotheimia angulata, one finds evidence of different conditions. Many specimens occur in the cliffs themselves, especially at Filey, but representatives of the species are scattered all along the Holderness coast as well. As a rule, instead of occurring in blocks, each specimen, complete or fragmentary, is found alone, and is generally in a gritty blue matrix of shale. This shale evidently weathered easily, for the fossils are comparatively clean. Most of these specimens are erushed. So far, we have found only one boulder of hard pale limestone containing this genus (Schlotheimia); and, as the small fossils which the boulder contained were mere casts in clear glassy calcite, not much was secured from it. One of the specimens, which apparently came from a clay, was identified by Mr. Buckman as Schlotheinuia exechoptycha (Wihner). He considers two other specimens of the genus submitted to him to be new forms. ‘The collections made by others along the coast contain several specimens comparable with Schl. trapezoidahs (Sow.), while we possess one which may be placed with Schl. ventricosa (Sow.). Bucklandi Beds. The derived fossils from the Bucklandi Zone deserve special note, for they are probably the most numerous of any, in consequence of so many boulders of hard dark bluish limestone presenting themselves to the hammer of the collector. 1 R. Tate & J. F. Blake, ‘The Yorkshire Lias’ 1876, p. 271. Vol. 69.] DERIVED CEPHALOPODA OF THE HOLDERNESS DRIFT. 173 Coroniceras rotiforme, although entered as doubtful in Yorkshire lists, is probably present in several varieties: for many fragments have been seen, and Mr. Morfitt possesses a fine example. These fragments are in a shale which is similar in character to that containing the angulate. Coroniceras sauzeanum (VOrb.) and Mtomoceras scipiontanum {d’Orb.), in spite of not having been found in place since Tate & Blake’s time, are really abundant as excellent casts in a certain very hard dark limestone, of which large, somewhat rectangular boulders are frequently secured, well filled with representatives of these species in various stages of growth. A glance at the appended list (p. 180) will show many names of the genus Coroniceras new to the Yorkshire lists. The same is also true of the Arnioceras group. Ooroniceras trigonatum has been well described by A. Hyatt*; but his figured types of the species are rather remote from our speci- men, which possesses a very massive body-whorl of acutely sagittate section. The grooves shown in the figures are absent from along- side the sharp keel of the Drift example. We have now seen on the coast fragments of four more examples of this bulky ammonite, although it does not appear to be represented in the museums, Arietites turnert (Sow.), or some near ally, is not infrequent as fragments, but we have not been able to secure a cabinet specimen, not even a fairly complete one. It will be at once called to mind that Sowerby founded this species on a Drift specimen from Norfolk. Arietites brookt Reynes has occurred more frequently, and con- sequently some good examples were obtained. The so-called *‘ Arnioceras semicostatum’ is so abundant in its various forms that it might be styled ‘the Ammonite of the Drift.’ It chiefly occurs by the hundred, in cubical blocks of the hard dark limestone so well known in English museums. Although these are always labelled ‘from Robin Hood’s Bay,’ it is suggested that they were really obtained by collectors from Drift material, since neither I nor any one whom J have ever met has found this limestone in place, although it has been much sought for. Again, the museum blocks can easily be matched along the Holderness shore to-day. Some specimens of this ammonite are found in a shaly matrix; but then they are not so well preserved. The first time that I visited Withernsea for collecting-purposes, there was a really wonderful display of this fossil. There had been a storm associated with a spring-tide, as is very usual on that coast, and apparently a big mass of shaly material had been washed up and scattered, for the beach was literally paved with semicostatum slabs for quite 100 yards. Such a display has never been seen since. The large ammonites of the zone are generally found as mere fragments; yet some excellent examples have been secured by other collectors, and are now housed in the local museums. * ‘Genesis of the Arietide’ Mem. Mus. Comp. Zool. Harvard, vol. xvi (1887-89) No. 3, p. 182 & pl. vi, fig. 3; pl. vii, fig. 1; pl. xii, fig. 15. 174 MR. C. THOMPSON ON THE [June 1913, Oxynotus Beds. The derived fossils torn from the Oxynotus Zone—applying the term in the inclusive sense, as used by Tate & Blake '—represent well all three divisions. Most of the characteristic forms are found. ipheroceras plani- costa occurs in very hard stones, which may only be the ground- down remains of nodules. 1 ; SHEET & Ly J” Y Y ye Soe Owurg to outricate titer bedding of the varvous rock-vpes, attempts to represent the geology are merely rough ap- preaim ation: S. wo gen | Seale 4 Miles =1 Inch ar £253,440. 2 * Ss 7 s 1p Miles ra \ DALMA wn? 3S = DiaGRAmmaATIC SECTION ALONG THE LINEA.B. VERTICAL SCALE EXAGGERATED. Meet nan urn ROCKS LATER THAN THE SCHISTS. mad HII eK Peat | | |e E : Vepee Geol Surv Nap, SHEET 44| SHEET 45 SHEET 36 = . y of, 7 THe Scuists / Owing to intrivate inter bedding of the various roch-types, attempts to represent Ge geology are merely rough ap- proxumalions. thvo gen eralized midices are given belowon account &' marked, differences tr Ue lower part of the sequence. The colounscheme tsexplamed at the bottom N.E.Part oF District LOCH AVICH een Slates, Grits, £ Lavas TAYVALLICH lack Slrtes arid Lumestones often pbb its Conglomerdite (Glen Arey) & Lavas CRINAN ts nud: Quartxrtes, with subordinate Slates & Limestones Grits and Quartzites, with subordinate Slates & limestones ARDRISHAIG _ SHIRA beol Surv. Map, Green Phy lites , with Dimestone (fine-grained) SHEET 37 2 pas a CaN eg cate ARORISHAIG ites, witly SHEET 29 |_ |stones. led Qeuurexites & Limiestones ST CATHERINES Graphite Schists Geol Surv. Kap, f . D i eee yY ; vonchallin Grey Phyllites, 4 @ Graphitic Rand, corresponding, a suggostedl, wh the X¢ Catherines Graprate Schists. a Dipa, amount in degrees S Urutilatory Dips [Sea Epudiorite Sills intruded x 4 tto all the aboveeoccept a, Meet for the upper portion. of © Pitching Folds the Loch Avich Slates a and. Orits, € og lee hie wen Slat Sor . "i Vol. 69.] LOCH AWE SYNCLINE (ARGYLLSHIRE). 307 reappeared in Ireland. The relative positions of the rocks of the groups had been proved by the speaker more than twenty years ago, and the conclusions reached were published in Sir Archibald Geikie’s first Presidential address to the Geological Society (1891), The Blair Atholl Limestone (believed by the speaker to be the ‘Tayvallich Limestone) was shown to be on one side of the Quartzite, and the Caenlochan Schist (Ardrishaig Phyllite) ou the other. At the extreme north-eastern end of this outcrop, the quartzite was very thin, and passed down insensibly into the underlying dark schist, which there intervened between it and the Caenlochan Schist. Proceeding south-westwards, one noticed first the occurrence of small grains of the dark material at the base of the quartzite, later ou small pellets, and finally in the area in question the original dark mud was at times completely eroded away ; but now pellets of it, of larger size, occur in the quartzite. The real evidence adduced by the speaker, on which the succession turned, had never been published. The AutHor, in reply, pointed out that Mr. Hill treated the mass of epidiorite in the vicinity of Loch Awe as a unit—either an immense sill or an immense lava. On this hypothesis Mr. Hill had, of necessity, set aside any interpretation involving the occurrence of lava, since parts of the mass showed definitely intrusive relations. The Author’s observations led him to regard the mass as a complex series of lavas and associated sills. s Replying to Mr. Barrow, the Author drew attention to a paragraph written conjointly by Dr. Peach and himself in the Geological Survey Memoir on Sheet 28 (Scotland), The paragraph followed upon a description of the succession in the Tayvallich peninsula, and ran as follows [18, p. 61 ]:— ‘Tt would be unnecessary to go beyond this, were it not that the relations of the Loch Awe Group in Argyllshire have been used in support of the theory of the ‘“‘unconformable quartzite” in Perthshire and elsewhere. The writers are now of opinion that the change of front in the Tayvallich district strengthens, by analogy, the alternative interpretation of the Perthshire sections, which has for years been identified with the name of Mr. Barrow.’ Since the above was written the Author had tried to reach greater certainty in the matter, but without success. The district lying between Loch Awe and that part of Perthshire in which Mr. Barrow had worked was very difficult indeed to interpret, Quite apart, however, from the doubtful analogy between Loch Awe and Hastern Perthshire, the Author, speaking without any special knowledge, believed that Mr. Barrow was right in regarding the Perthshire quartzite as an interstratified member of the Perthshire sequence, and not an unconformable later group for ever making its appearance in isoclinal synclines. Mr. Barrow had also referred to Islay. Here the Author was on familiar ground; and, while admitting certain general resem- blances between the Islay-Jura sequence and that of Loch Awe, he found the differences of detail so considerable that he preferred to maintain an agnostic attitude in regard to matters of correlation. 303 DR. A. M. DAVIES AND MR. J. PRINGLE ON [June 1913, 16, Me Two Deer Bortnes at Catverr Station (Norte Bucxrne- HAMSHIRE) and on the Patmozorc FLoor norrH of the THames. By Axtavr Moriey Davins, A.R.C.S., DSe., F.G.8., and Joun Prineie, of H.M. Geological Survey. (Read February oth, 1913.) [Prarns XXXIII & XXXIV.] ConTENTS. Page Ue Entbrodchiomieieh vate rgsee to eek tee te tere a eae 398 IL. Description of the Borings .................2.0---2-> BEeHO 310 (1) The Hastern Boring.—General Remarks ......... 310 (a) Jurassic Rocks ...........-..... Siesta veartucets 312 (O) IallexoyfoOn@ IROEKS cossccnscceecoosnadonsesdnocecons 322 ()) Alas) Western IXORINS .-spococenssecessanqssnescoosons 326 INL, JEvesovOlOeerll INOWES cosdodsorbancouds dooacaoaeevenanecooe 329 ID/5 GNing THe wOlNeNy IDOE sn scacnoaseckba0gsdscons00Gsebcuoodone 332 V. The Paleozoic Floor north of the Thames............... 334 VAEAS una many siete. he sitaees de tooee a pasce seta eeeb eet ea eaeeert 338 I, Inrropucrion. [A. M. D.] ‘CaLyerT Station is situated on the main line of the Great Central Railway, +9 miles by rail from London (Marylebone Station) by way of Aylesbury, and about 11 miles north-west of the latter town. - “Calvert ’ is not the name of any village or hamlet, but the station was so named in memory of a former distinguished resident in the neighbourhood, General Sir Harry Calvert. It will not be found, therefore, on any map issued prior to the opening of the railway; and, for the benefit of any observers who may seek to locate the borings about to be described upon the only published geological map of the district (the original 1-inch sheet, 45 8.E.), it may be stated that the station lies in the south-eastern angle of the ‘T-shaped road-junction, about an eighth of an inch north of the second ‘n’ in ‘Charndon Lodge.’ The road—really a green lane— which forms the stem of the T constitutes the boundary between ‘the parishes of Charndon on the west and Steeple Claydon on the east. One of the borings is in the former parish, one in the latter. Shortly after the opening of the railway in 1898, the late Mr. Itter, of Peterborough, opened a branch of his brickworks -on the Charndon side of the green lane, and very extensive exca- vations have been made in the shaly clays of the ornatwm zone. In 1905 a boring for water (hereinafter referred to as the Western Boring) was made in the brickfield; but only salt water was -obtained, and at a depth of 380 feet inflammable gas. was met with and has been coming off ever since. At 445 feet 8 inches the boring was abandoned. No use was made of the gas, and six years passed before its existence came to public knowledge, when, in 1911, the Guildhall Syndicate was formed to make further investigations. They set to work to clear out the Western Boring and carry it deeper -down, and at the same time started a new boring (which we call Vol. 69. ] TWO DEEP BORINGS AT CALVERT STATION. 309 the Eastern Boring), beginning with cores 18 inches in diameter, with the view of reaching a depth of 2000 feet if necessary. The actual depth reached: was about 1398 feet,in April 1912. The old boring was restarted, with cores 2 inches in diameter, at 446 feet and continued to 649 feet by November 28th, 1911, when it was stopped. We are very greatly indebted to Mr. A. Hiorns Jr., resident engineer to the Guildhall Syndicate, for allowing us opportunities to examine and take samples of the cores; for the readiness _ with which he has given us information on matters that we could not investigate personally ; and for having carried on the Eastern Boring, in the hope of adding to geological knowledge, after the prospect of economic success was at an end. During the progress of the boring, one of us paid seven visits, at intervals between September 1911 and April 1912; but some of these visits were limited to so short a time, that the examination of the cores was much less thorough than was desirable. Mean- while the other author, accompanied by Mr. J. M. Muir, proceeded to Calvert in December and January, to examine and collect from the cores for the Geological Survey. The two series of observations and collections were thus to some extent supple- mentary ; but, owing to the confidential nature of the information, no comparison of the results was possible until after the former author had completed a paper and presented it to the Society. At the suggestion of the President (Dr. Strahan) he then examined the material collected by the Survey, and discussed the correlation of the strata with the second author. As a result some modifi- cations in the interpretation became necessary ; but, as the key to part of the Jurassic sequence lay in certain unpublished information obtained by the Geological Survey during the excavation of the Fritwell railway-cutting, it was seen that only by a joint paper could the boring be adequately dealt with. Hence the present communication. The parts that are the work of either author exclusively (or almost so) are indicated by his initials. While each of us is generally responsible for the identification of fossils in the sections which he has initialled, acknowledgment of kind assistance must be made to Mr. 8. $8. Buckman (who identified all the ammonites and several of the brachiopods), to Dr. Kitchin, Dr. Matley, and Mrs. Shakespear. We must also acknowledge the help in the correlation of the Oolites derived from the papers of Mr. E. A. Walford and Mr. L. Richardson, to which one of us must add his thanks to the former gentleman for personal exposition of the Sharp’s Hill section. The photomicrographs were taken in the Research Laboratory of the Imperial College of Science & Technology by Mr. H. G. Smith, B.Se., to whom we are much indebted. To Prof. T. T. Groom one of us is indebted for the loan of Malvern specimens, for comparison with the sills passed through in the boring. A selection of cores has been secured for the Museum of the Buckinghamshire Archeological Society, at Aylesbury. 310 DR. A. M. DAVIES AND MR. J. PRINGLE ON [June 1913, Il. Drscrretion oF THE Bornes. (1) The Eastern Boring.—General Remarks, [J. P.] The site of the Eastern Boring is in a field in Steeple Claydon parish, numbered 15 on Sheet XXII-2 of the =4,, Ordnance map (Buckinghamshire) dated 1899, at a point immediately north of the words ‘ Cattle Pens’ on that sheet. The height above Ordnance datum may be estimated as 290 feet, by reference to the nearest indicated altitudes on the adjacent roads. DETAILS OF THE STRATA PASSED THROUGH IN THE HasTERN Borne. Thickness Depth in feet inches. in feet inches. Sunface-soileeueeeecia aterm srs secre 4 0 = : (Dark-blue and grey clays with occa- © 8 | sional nodules: the basement-bed is a 2 = 4 tough, brownish, shelly clay full of frag- iS = | ments of Cosmoceras, Belemnites, Gry- BES pied; Cbemurcdt ise Meth Me nace vs uence 93 3 97 3 Os Non-sequence.! Bluish-grey and grey limestone, oolitic in places, and becoming earthy below: WHAOREMIVTEPOWNS Gascodbesnansannos sacutoonsnc if 9 Dark-grey earthy limestone ..............- 9 | Hard grey limestone, shelly in places, fragments of Ostrea abundant; base of i | bed yellowish and somewhat sandy...... 2 0 Bf LO, QDS SECM IOI pone sceadaaacesessodses sa2088e 5 6 = | Grey earthy limestone, with plant-frag- Z 4 TPUVETINNS) BY NOl EPPO, «sep cenaa sede soe sc25005- 1 3 = | Bright bluish-green clay .................. 3 4 | Grey earthy limestone .............--..++- 2 0 5 | Irregularly thin - bedded bluish - grey = | limestone, oolitic and shelly in places . 1 6 Dark-grey earthy limestone on paler grey blotchy limestone, oolitic in places. 7 0 Grey marly clays, passing down into | brown and greenish clays, with a bed of green sandstone and a hard band of | grey limestone. Lignite plentiful ...... 16 9 136 0 Non-sequence. 38 9 (Very compact, blotchy, grey limestone | (possibly equivalent to ‘cream-cheese’ | OTD) coocosnne p05 20dsd5canmonapaoaasdgnza09000 50-7 1 6 Yellowish marly limestone, shelly in ( DIACES rs... a cneeee teen scepecarecee se ctaemmereee 2 0 | Grey marly limestone, full of dark | grains: limestone becoming darker below. :; 3.4 sspmeaepeere ence ceeeueet sn a-nececeee 6 0 Grey blotchy limestone yielding Zere- OTT (NAW OWNED sorsecroce: s50b0-90590000" 2 6 |, Grey marl Se ea eaaeeke cece eceoeeck cate 6 1 The term ‘ non-sequential’ was proposed by Mr. 8. 8. Buckman, to denote the relationship of strata ‘when the sequence is incomplete, but the planes of the deposits are practically parallel’ Q. J. G. 8. vol. li (1895) pp. 390-91. Me Vol. 69.] Curtepinc-NortToN Domertran— algovianwm zone. OIARMOUTIIAN— capricornus to amesont zones. Great Oouirr Serres. LIMESTONE. TWO DEEP BORINGS AT CALVERT STATION. oil Thickness Depth in feet inches. in feet inches. 4 Dark marly clay, full of Ostrea sowerbyi { \ ( | ( ( | M. & L.and Rhynchoneila sp. [of the COLCUNTA MUNDO Stee daa. sape asec ncse see sel-c Grey limestone, soraewhat earthy: un- IOSEH DUST ROWEH) Conca dtduccanaeeeeeaueenece scaeee Dark-grey marl: Pholadomya cf. del- LOCO CAD ING a Iities eel sinc seeceriesceeceesess No core seen between 156 feet 6 inches and 181 feet 9 inches. Beds deseribed on the borer’s record as soft, dark-grey, BAM Cys SMAlES nec teien Seeeetcnsstcicncecevedeb Dark-grey shaly limestone.................. Grey limestone with Ostrea sp...........+- IDevdte immer hy loehael)” Sceoaboncede tar caus sHeaan ura aasecne OG.) No, 274. bo bo Co ba | [SeMie a) 140 I oo kD ice) Oo bo 0 6 6 [ory 195 203 211 214 6 6 312 DR. A. M, DAVIES AND MR. J. PRINGLE ON [June 1913, Unconformity. Thickness Depth in feet “inches. in feet inches. (Soft greenish-grey shales, red-stained in places, particularly on the joint- faces. Dip varying from 65° to 70°.. 36 6 480 0 Soft dark-red and green micaceous shales: fragments of Clonograptus (2) at, AQ O tee b sesi este sistem Mela SIN Dae 13 6 495 6 Soft greenish - grey shales, passing downwards into grey shales: Clono- graptus at 496 feet ...0.2.......7......- 2 6 496 0 Jointed grey micaceous shale, with two sills of olivine-basalt at 570- | 572 feet and 606-608 feet. Clonograptus and Obolella abundant | at 498, 517, and 530 feet. Be- | tween 481 and 500 feet the shales dip steadily at an angle between 65° and { 70° ; at 555 feet the dip decreased to 49°: Clonograptus, Obolella. About 600 feet, abundant Clonograptus and Obolella. At 635 feet, dip=44°: / Clonograptus. At 740-742 feet, ( Lower TREMADOCTAN. Shineton Shales graptolites and Obolella. At 783 feet, dip=49°. At about 845 feet, dip=40°, rising locally to 80° : Clono- graptus. At961 feet, worm-castings. At 1185 feet, dip=51°. At about 1165 feet, dip=48°: abundant frag- ments of graptolites. From 1180 to 1220 feet, the beds are almost vertical. At 1280 feet, dip=59°. At 1398 feet, harder rock touched, no cores drawn Gagneous) gilli?) eee eee seen eae 902 0 1398 O Estimated true thickness=about 480 feet. Total apparent thickness ...... 954 6 (a) Jurassic Rocks.—() Oxford Clay. [J. P.] Owing to the state of the cores, it was impossible to secure exact details of the Oxford Clay passed through in the Eastern Borehole. The information obtained from the borer’s journal, however, shows that grey and blue clays, some of which were hard and tough, were met with to the depth of 95feet. Below this point was a hard, tough, brownish clay, full of broken shell-fragments and some lignite; and from this portion of the core the following fossils were obtained :— Lignite, Cosmoceras sedgwicki (Pratt). Gryphea bilobata J.de C. Sow. Cosmoceras stutchburyt ¢ (Pratt). Belemmites owent Pratt. In Messrs. Itter’s brickyard—the site of the Western Borehole— a fine section is obtained of nearly all the beds passed through in the Eastern Boring, and from this locality Dr. Davies & Mr. E. Neaverson, B.Sc., of Aylesbury, collected, among other forms, Cosmoceras elizabethe (Pratt) and C.jason (Reinecke). From these forms, and from the evidence furnished by the lowest bed of Oxford Vol. 69.] TWO DEEP BORINGS AT CALVERT STATION, ols ‘Clay in the borehole, it can be safely assumed that all beds passed through at Calvert, to the depth of 97 feet 3 inches, belong to the ornatunr zone.' Gi) Forest Marble. [J. P.] The Oxford Clay rests upon a grey, partly oolitic, and somewhat earthy limestone; but, unfortunately, no specimen which showed the nature of the junction was obtained. The tough shelly clay with Cosmoceras (described above) occurred, however, at the actual base of the ornatum beds in the borehole, and no trace of any conglomerate was found. The limestone on which the clay reposed was unfossiliferous, and its inclusion in the Forest Marble is made ‘on lithological grounds. In appearance the bed is similar to the limestones associated with the green clay. Dr. Davies, who ex- amined this and other limestones under the microscope, gives details of its structure on p. 318. It is oolitic, and is thus quite unlike any of the beds of the Cornbrash; moreover, it passed gradually downwards into limestones which contained Forest- Marble fossils, so that there can be no doubt that it is correctly included in that formation. ‘Thus there is a marked non-sequence, iboth the Kellaways Rock and the Cornbrash being absent. The details of the Forest Marble at Calvert: show that the upper ‘portion of the group is more calcareous than the lower, and in this respect they agree with the descriptions of the various sections of the formation exposed in the Bicester neighbourhood. The lime- ‘stones in the core differ considerably in texture and purity: some beds are bluish grey, oolitic, and shelly; while others are softer, ‘darker, and earthy, and frequently contain irregularly-shaped lumps -of pale-grey clay. It was noticed also that many tube-like hollows, each filled with a marly and markedly-oolitic clay, traverse the "beds of some of the more clayey limestones. The lower portion -of the group is chiefly composed of grey, brown, and greenish clays, with a bed of greenish sandstone. Unfortunately, the cores were badly obscured at this point, and the details were somewhat difficult ‘to secure, but those given on p. 310 probably represent the correct order of their succession. The occurrence of green or greenish clays in the Forest Marble is characteristic. They are met with in all the sections of the formation that are exposed in the railway- ‘cuttings between Blackthorn Hill and Ardley Wood, near Bicester, 1 [The term ‘ornatwm zone’ is here used in its wide sense: at least two horizons can be distinguished within it in England —a higher duncani zone with pyritized ammonites, seen at Summertown (Oxford) and many places in ‘the Peterborough district; and a lower zone with crushed ammonites, known -at Christian Malford, and Dogsthorpe (Peterborough). It is the latter zone which is found at Calvert: it is usually termed the jason zone, but this is an unsatisfactory name, as the identity of the index-species is uncertain. Between these two zones in France and South Germany lies the castor and polluwx zone, with a fauna unknown in England. See L. Reuter, ‘ Die Ausbildung des “Oberen Braunen Jura im Nordlichen Teile der Frankischen Alb’ Munich, 1908, pp. 75-81.] x2 Fig. 1.— Vertical section of the and they have been noted’ Eastern Boring. in the shafts at Dover and in Tt Hie : the cores of the Brabourne f = s. [The arrows indicate non-sequence ] Gorahelen Soil-4 A critical comparison of = the Forest Marble passed OS, through at Calvert, with the sections exposed in the new railway-cuttings near Bices- ter, shows some interesting points both of resemblance and of difference. The forma- tion in the Calvert borehole- is considerably thicker than any of thesections where the whole of the beds have been cut through in the Bicester cuttings. At Blackthorn Hill oe = = the Forest Marble is only olan Ae —— 21 feet 9 inches thick?; in the cuttings between Buck- nell and Ardley Wood the- details show the formation to be slightly thinner.* At Calvert the beds reach the. total of 38 feet 9 inches, and are thus very nearly twice as thick. In the borehole, however, the thickening appears to have taken place in the clays. In the section at Blackthorn Hill? there is a bright bluish- green clay to which Mr. Bar- row drew special attenticn, and he remarked that its presence could scarcely be missed even in a hand-boring.. A clay indistinguishable from the Blackthorn-Hill bed was passed through at Calvert. It thus appears to mark a >t Forest Marble [Fa-+: 889" Great Oolite i ase 96 Ei Chipping Norton L*>t= Algovianun Zone = Capricornius Zone? Striatu m Zone | Jamesoni Zone SS =>, Lower» Tremadocian (Shineton Shales) 1G. W. Lamplugh & F. L. Kitchin, ‘On the Mesozoic Rocks- in some of the Coal-Explorations in Kent’ Mem. Geol. Sury. 1911, pp: 28 & 48. 2 G. Barrow, ‘The New Great Western Railway from Ashendon to Aynho, near Banbury’ Sum- mary of Progress for 1907, Mem. Geol. Surv. 1908, p. 143. 3 Ibid. p. 149. + Lbid. p. 145. Vol. 69.] TWO DEEP BORINGS AT CALVERT STATION. 315 well-defined horizon. Taking this bed of green clay as a datum, we found that in the borehole there is 14 feet 9 inches of grey earthy and oolitic limestones between it and the Oxford Clay ; while at Blackthorn Hill a thickness of 18 feet 3 inches is recorded between it and the base of the Cornbrash: thus there is a remarkably close agreement. Below the green clay at the latter locality, however, the clays are only a little more than 3 feet thick, whereas in the cores at Calvert 27 feet of clays are recorded. Even allowing for all possible chances of error, by excluding the limestones below the green band from the measurements, there still remains a considerably greater thickness of clay. Excepting the highest bands of limestone, the Forest Marble is fairly fossiliferous throughout ; but, as a rule, the forms are poorly preserved. Some of the limestones are shelly, Ostrea appearing to be plentiful in some beds; but the fossils were difficult to extract owing to the hardness of the limestone. In the grey earthy lme- stones overlying the band of green clay Pteroperna costatula (Desl.) was abundant. The basal clays contained a considerable quantity of lignite. The following is a list of the fossils obtained between the depths of 97 feet 3 inches and 136 feet :— Lignite. | Pseudotrapezium (1) caudatum Acrosalenia hemicidaroides Wr ight. (Lycett). Serpula sp. Pteroperna costatula (Desl.). Astarte sp. Trigonia morctoni Lycett. Gervillia crassicosta Morris & Lycett. | Trigonia pullus (2) J. de C. Sow. Modiola imbricata J, Sow. | Trigonia ef. scarburgensis Lycett. Modiola sp. | Nerinea sp. Nucula (2). | Nerinella funiculus (Desl.). Ostrea sp. | Nerinella sp. Pecten (Camptonectes) annulatus (?) | Pleurotonaria (?). J. de C. Sow. | Crustacean remains. Perna sp. | Fish-fragments. Pholadomya sp. (iii) Great Oolite Series. [J. P.] Beneath the clays of the Forest Marble the cores showed a series of marly limestones passing downwards (according to the borer’s record) through a thick band of dark grey sandy shales into marly clays and limestones. The lowest bed is a thinly-bedded limestone with lignite. Dr. Davies has described the microscopic structure of a number of the limestones on p. 318, so that few further observations need be added to his descriptions. Nearly all the beds are dark grey, and this coloration is due to the presence of numerous minute black fragments of limestone which are very abundant in some of the clays. The uppermost bed of the section immediately underlying the greenish clays of the Forest Marble is a compact, blotchy, grey limestone ; and, although it differs somewhat in colour from the ‘Cream-Cheese’ top of the Great Oolite exposed in the Bicester cuttings, it possesses so many of the characters of that bed that its relationship was easily recognized. Dr. Davies’s observations 316 DR. A. M. DAVIES AND MR. J. PRINGLE ON [June 1913, on the microscopic structure and included organic remains of the Calvert rock confirm its correlation with the Bicester bed. The upper surface of the limestone is irregular and piped, and the over- lying clays extending downwards into the pipes present an uneven junction. Similar irregularities of surface of the ‘Cream-Cheese ” top were noticed in the Bicester cuttings, and they are doubtless the results of contemporaneous weathering. The sudden passage upwards of a fairly pure limestone into clays with lignite denotes a considerable change of level in the area of deposition; and the fact that at Calvert root-like processes were seen to extend down from the overlying Forest-Marble clays into the infilled hollows of the limestone, suggests that for some time the ‘ Cream-Cheese’ top was a land-surface.1 There is at Calvert, therefore, as well as in the Bicester cuttings, a non-sequence between the two groups. Underlying the highest member of the Great Oolite is a yellow- ish marly limestone, 2 feet thick. It is the only bed that possesses the characteristic colour of the Great Oolite limestones exposed in the railway-cuttings between Bucknell and Ardley Wood. Unfortunately, the cores of the sandy shales were not. preserved at the boring, and so no comparison is possible; it is probable, however, that they represent the Stonesfield Slate. The remainder of the section consists of grey marly clays and limestones, which agree closely in character with the lower beds of the Great Oolite exposed in the long railway-cutting between Ardley Wood and Fritwell Tunnel, the details of which are not yet published. The limestones and clays of the Great Oolite at Calvert are, generally, fossiliferous; but the fossils, like those of the Forest Marble, are badly preserved, the majority of them occurring in the form of casts. The most abundant forms are Ahynchonella and Ostrea; a horizon between the depths of 185 feet 3 inches and 193 feet 9 inches yielded hundreds of specimens. ‘This band is. clearly comparable with the marls overlying the Newran Beds in Sharp’s-Hill Quarry.’ In the present state of knowledge no attempt has been made to give a definite name to the species to which the Rhynchonelle belong, but the type with which the forms appear most closely allied is named in the appended list. Regarding the: other fossils which were collected little need be said, since most of them are characteristic of the Great Oolite. The Ostrea which is. recorded in the list as Ostrea sp. nov.(?) is apparently an undescribed form, and still remains to be identified. Many specimens of Pholadomya ct. deltoidea (J. Sow.) were obtained at the depth of 156 feet, and they are similar to the Ph. deltoidea collected by Mr. J. Rhodes and Mr. H. B. Woodward from the Fuller’s-Earth 1 [On clearing the surface of the Great Oolite, after the removal of the core to the Aylesbury Museum, I found that the surface was very irregular, the dark patches in the limestone having weathered out into rounded prominences, almost certainly the result of subaérial weathering.—4. MW. D.] 2 L. Richardson, ‘The Inferior Oolite & Contiguous Deposits of the Chipping-Norton District’ Proc. Cotteswold Nat. F. C. vol. xvii, pt. 2 (1911). p- 207; also E. A. Walford, ‘On some New Oolitic Strata in North Oxfordshire’ Buckingham, 1906, p. 8. Vol. 69.] TWO DEEP BORINGS AT CALVERT STATION. 317 Rock of Thornford and Milborne Port.! The type described by Sowerby came from the Oxford Clay of Peterborough, but the form shown in his figure does not appear to differ from the forms found in the Great Oolite. The following is a list of the fossils obtained from the cores between 136 and 195 feet :— Lignite. | Pecten (Camptonectes) annulatus (?) Sponge-spicules. J. de C. Sow. Bryozoon (?). | Cf. Pecten (Camptonectes) lens J. Sow. Rhynchonella sp. [of ‘concinna’ type]. | Pholadomya cf. deltoidea (J. Sow.). Rhynchonella sp. oe ‘obsoleta’ type]. Pholadomya heraulti Ag. Terebratula bathonica 8.8. Buckman. | Pholadomya sp. Terebratula globata auctt. ‘| Pleuromya sp. Terebratula sp. Pseudotrapezium (?) caudatum (Lyc.). Astarte (2). Pteroperna costatula ? (Desl.). Cyprina (2). | Tancredia (2). Grammatodon hirsonensis (d'Arch.). | Trigonia cf. pullus J. de C. Sow. Gresslya peregrina (Phill.). Unicardium impressum Morris & Homomya gibbosa (J. Sow.). Lycett: Modiola imbricata J. Sow. | Unicardium ef. parvulum Morris & Modiola sp. | _ Lycett. Ostrea sowerbyi Morris & Lycett. | Natica cf. zelima d’Orb, Ostrea sp. nov. (?). (iv) Chipping-Norton Limestone. [J. P.] Underlying the thinly-bedded limestone at the base of the Great Oolite at Calvert is a yellowish oolitic limestone, which passes below into a sandy limestone with many oolitic grains. The lowest bed is false-bedded, and rests on the shales of the algovianwm zone. By their characters the limestones were recognized as representing the Chipping-Norton Limestone. Unfortunately, however, they proved but sparingly fossiliferous, and so their correlation is based entirely on lithology. Dr. Davies had sections made of several specimens; and, as a result of his examination of their microscopic structure, he states that they are identical with Bed 22 of Mr. E. A. Walford in Sharp’s-Hill Quarry.” Since there was no trace of the Newran Beds in the cores, there is thus a marked non-sequence at the base of the Great Oolite. In the section at Sharp’s Hill the beds between the Rhynchonella-Ostrea band and Bed 22 of Mr. Walford’s succession reach the thickness of about 20 feet 7 inches (loc. cit.). At Calvert there is about 5 feet of marls and limestones between the same horizons; therefore, the thickness of beds unrepresented between the Great Oolite and the Chipping-Norton Limestone is nearly 16 feet. The following fossils were found in the sandy limestones; the brachiopods, however, were too fragmentary for identification. All the specimens are in the collection of Di. A. M. Davies. Ehynchonella sp. Ostrea sowerhyt Morris & Lycett. Terebratula sp. Ostrea aff. acuminata J. Sow. 1 H. B. Woodward, ‘ Jurassic Rocks of Britain’ Mem. Geol. Surv. vol. iv (1894) p. 237. : ~ 2 «On some New Oolitic Strata in North Oxfordshire’ Buckingham, 1906, p. 10. 318 DR. A. M. DAVIES AND MR. J. PRINGLE ON [June 1913, (v) Microscopic Structure of the Great Oolite Series. [A. M. D.] Limestone at 98 feet.—This, the topmost bed of the Forest Marble, is somewhat oolitic, the grains having large nuclei with a rather thin coating ; fragments of shells, often waterworn, abound, including echinodermal, bryozoan, brachiopod, and gastropod fragments; and there are also seen under the microscope what appear to be waterworn fragments (up to 1 mm. by 0°3 mm.) of a limestone of the same structure as the crystalline matrix in which they are embedded. Limestone at 119 feet.—This shows an extremely fine- grained calcite-matrix, in which are set (a4) a very few quartz- grains, measuring about ‘05 mm. in diameter ; (6) more frequent grains of clear calcite, of about the same size; (c) abundant waterworn calcareous fragments with a dusky appearance, also of the same size or a little larger (up to 0:1 mm.), including some foraminifera and echinoderm-fragments. A limestone at 123 feet is very similar. The top bed of the Great Oolite (at 136 feet) has a very finely-crystalline calcite-matrix, with foraminifera, echinoderm- fragments, shell-fragments, and rolled minute grains of dusky calcite. ‘There are a few tubular rod-like bodies, which may be sponge-spicules. These, however, are so scarce that they would have been overlooked if they had not been specially searched for, on account of their abundance in the ‘Cream-Cheese’ bed of the Bicester railway-cutting, with which the bed now described is correlated. The two beds are of generally similar structure, but the fragments embedded in the matrix are decidedly smaller in the ‘ Cream-Cheese’ bed. Great, Oolite limestones at 143, 144, 146, 155, 191, and 195 feet.—While varying much in coarseness of grain and pro- portion of matrix to fragments, these show certain features in | common. They are composed largely of organic fragments—of echinoderms, brachiopods, and lamellibranchs—with occasional oolite-grains and many rolled fragments of limestone, conspicuous by their duskiness, varying from 0-2 mm. up to 1 mm. in diameter. In several cases, fragments of oolitic limestone occur, a fact which suggests that many of the isolated oolite-grains may be derived. In some beds, subangular quartz-grains are abundant (=about 0-1 mm. in diameter). The bottom bed of the Great Oolite (at 195 feet) shows scattered oolite-grains and fragments of oolitic lime- stone, all with the dusky margin which appears to denote derivation (Pl. XXXITI, fig. 1). Thus, throughout the whole of the Forest Marble and Great Oolite we find constant evidence that, while the limestones were being deposited, other limestones of very similar character and Vol. 69.] TWO DEEP BORINGS AT CALVERT STATION. 319 oolitic limestones also were undergoing denudation at no great. distance. This fits in well with the repeated non-sequences of which the stratigraphy gives evidence. Oolitic limestone at 197 and 203 feet (Chipping-N orton Limestone).—These are quite typical oolitic limestones, the only ones in regard to which it can be confidently asserted that the majority of the grains are of contemporaneous origin. The two beds are separated by very sandy limestones, in which, however, there are also abundant oolite-grains. Kven these beautifully oolitic rocks give the same indications of the destruction of pre-existing oolitic limestones as those that we have seen in the overlying strata. Thus not only do we find occasional fragments of oolitic limestone in which several broken oolite-grains are still united by the calcite-matrix, but we even find worn oolite-grains serving as nuclei to new oolite-grains ’ (Pl. XXXITI, fig, 2). Another curious appearance seen in these oolitic rocks under the microscope is the indentation of the margins of oolite-grains, usually by angular sand-grains, but sometimes by other oolite- grains or by shell-fragments (Pl. XX XIII, fig. 3). It is not easy to frame an explanation of such a structure. The only other rock in which I have detected the same appearance is the Chipping- Norton Limestone (Bed 22 of Mr. Walford’s succession) of Sharp’s Hill. That limestone has much more abundant quartz-grains, also its oolite-grains are rather smaller and have sand-grains much more frequently for their nuclei; but these are differences of degree, rather than of kind. The general appearance of the two rocks is similar, and worn fragments of oolitic limestone occur in both. (vi) Lias: Domerian? and Charmouthian. [A.M. D.] The change from the variable beds already described to the markedly-uniform Liassic shales was very striking. The writer of this section fortunately saw the. greater part of the uppermost 100 feet of Lias cores soon after they were brought up, at the end of October 1911: for, being unprotected from the weather, they were soon reduced to mud. The finding of a capricorn ammonite at 1 [It was suggested by Dr. Matley during the discussion that these derived fragments of oolitic limestone might be of practically contemporaneous origin, beine broken-up as soon as formed. This may be so in the last-mentioned case (worn oolite-grains as nuclei to new)grains), but I do not think that the explanation can apply to the majority of cases.—d. M. D.]| 2 As it is desirable, on several grounds, to ke able to distinguish between the Middle Lias, in the restricted sense of the Geological Survey, and the underlying clays which are also included in the Middle Lias by many authors, I follow Mr. Buckman in restricting the name ‘Charmouthian” to the latter and adopting for the former Dr. G. Bonarelli’s term ‘Domerian’ (Rendiconti R. Ist. Lombard. ser. 2, vol. xxviii, 1895, pp. 326, 415). According to Dr. A. Bettoni, the term should properly be ‘ Domarian,’ being derived from Monte Domaro, called Monte Domero by Bonarelli (Mém. Soc. Paléont. Suisse, vol. xxvii, 1900, No. 3, p. 3, footnote). 320 DR. A. M. DAVIES AND MR. J. PRINGLE ON [June 1913, about 300 feet at once made clear the importance of the non- sequence between Oolites and Lias. Although no ammonite was then found at any higher level, the presence of the same Nuculana at intervals throughout these 100 feet of shale indieated that there could be no other break in the sequence, and suggested thati no. stage higher than Charmouthian was present. Long afterwards it was discovered that a section of core which had been placed near the Oxford-Clay cores, and had been taken for part of them, con-- tained the same species of Nuculana as that already mentioned. Fragmentary ammonites which it also contained were at once submitted to Mr. Buckman, who identified them as belonging to the algovianum (lower margaritatus) zone. It became evident that. the cores had been displaced, and doubt was thus thrown upon the: record of depth at which other fossils had been collected. This doubt is of little consequence, except in regard to those recorded as coming from the depth of 210 feet: in that case it becomes un-: certain whether they come from below, or from above, the horizon adopted as the boundary between Domerian and Charmouthian. Except for three interruptions, the Lias from top to bottom, 240: feet in all, appears to consist of shales of very uniform character. Those near the base are distinctly less fissile than those towards the top, but otherwise the only differences noted are in colour; and it may be doubted whether these really exist to the extent recorded, for specimens which at the time of collecting were noted as brown have by drying become pale grey. Although few cores were seen between 300 and 430-feet, there is no reason to. suppose that any great variation occurred between those depths. Septaria were met with at several levels. The three interruptions already mentioned are a bed of sand, 3 feet thick, reported near the top, and two fossiliferous limestones (each some 24 feet thick), at about 354 and 440 feet respectively. The evidence of the misplaced core proves the presence of the algovianum zone. It is probable that this came from immediately below the Chipping-Norton Limestone, because there is no evidence of any higher zone of Lias. In the absence of any other evidence it will be convenient to take the bed of sand at 211-214 feet as. marking the base of the Domerian, which would then be represented by the topmost 11 feet only. Of the zones of the Charmouthian, only two are clearly proved present—ammonites of the striatum zone were found at 300 and 354 feet, and brachiopods of the jamesonz zone at 438-440 feet. It is reasonable to assume that some part of the 86 feet from 214 to 300 belongs to the capricornus zone, and some part of the 84 feet between 354 and 438 to the valdani zone. The minimum thickness of the striatum zone is 55 feet (300 to 354 inclusive). The fossiliferous limestone near the base (and with it, presumably, the underlying 3 feet of unfossiliferous clay) may safely be ascribed to. the jamesoni zone, on the evidence of its brachiopod fauna. The most abundant form is Zedleria waterhousei (Davidson), the specimens being in precise agreement with some from the jamesone Mc Ea Me sie ae Vol. 69.] TWO DEEP BORINGS AT CALVERT STATION. S21 zone of the Radstock district. Zerebratula radstockensis and some of the species of thynchonella tabulated below are no less charac- teristic ; and, although the Spiriferina comes nearest to one which is said to occur in the striatum zone of Cheltenham, and Ith. rimosa-- multiplicata is placed by Mr. Buckman as sériatwm-valdani, the balance of evidence is decisive for the jameson zone. But the most interesting discovery in this basement-bed was a derived fragment of Echioceras microdiscus (Quenstedt), a raii- costatum-zone ammonite. That it is derived was shown by the following facts, determined during extraction :—(1) It is the internal cast of the body-chamber only, and as it lay in the rock there were portions of the shell adherent in some parts and not in others; (2) the matrix of the cast was not the same as that of the rock around ; (3) it was standing vertically. We have here, then, con- ditions very similar to those known at various places near Radstock, where derived raricostatum-zone ammonites are found at the base of the armatum zone. It is important to notice that the small thickness of Lias in this boring is due to the absence of many zones, not to the thinning of those that are present. The thickness of the zones represented is normal; indeed, it is if anything greater than might have been expected—ereater than that of the same zones at Lyme Regis, for example. List or Fossins rrom Tun Lias—Dommrian anv CiarmMouTnoran— ALGOTVIANUM TO JAMESONI ZONES. [* In the collection of H.M. Geologieal Survey. + In the collection of Dr. A. M. Davies. | From an unknown depth, probably between 203 and 210 feet (algovianwny zone) :— tCristellaria sp. |Nucula cordata (?) Goldfuss. *+ Chlamys 2 (immature, maximum | *tNuculana et. quenstedti (Tate). length=5°5mm., showing abrupt | * er a Wolk Go. | TWO DEEP BORINGS AT CALVERT STATION. 333 from some part of the Lower Oolites at Oxford, and from the ‘Corallian in many places,’ as well as from the Kellaways Rock. As to (2), the comparison seems to be based upon the engineer’s ‘description only, no specimen of the Bletchley rock having been preserved. As to (3), we read that “all the larger specimens were broken up by the chisel ; those preserved are ‘chiefly frag:nents of the stems and arms of small crinoids, with several pieces of small belemnites and fragments of bivalve shells,’ which might quite well be Liassic. On the other hand, Prof. P. F. Kendall has pointed out * the ‘difficulties involved in any attempt to interpret this boring and to bring it anto accord with the... borings at Stony Stratford.... These two borings’ [he remarks] ‘indicate the presence of a normal series of Oolite and Lias within 5 miles of the Bletchley boring, and the intervening distance, -5 miles, is insufficient to explain the absence of at least some of the beds -at Bletchley, just as the normal dip of the Oxford Clay in the district would not account for the presence of so great a thickness of the Oxfordian beds. I suspect that some beds of greater geological age than the Oxford Clay occur in the lower part of the Bletchley borehole.’ To the difficulties pointed out by Prof. Kendall, we would add the lithic character of Nos. 9-13. In these beds, which on the usual interpretation are in the middle of the Oxford Clay, out of a total thickness of 33 feet, 18 feet 9 inches consist of oolitic and erystal- line limestones. These invite comparison with the Forest Marble of the Calvert Boring, and we suggest the following correlation of the two borings :— Calvert. Bletchley. Feet inches. Feet. Oxtordl Clay yee eae cues 95 3 192 Forest Marble ............ 38 9 33 Great Oolite, etc. ......... 67 O absent ? Lias (Charmouthian) ... 240 6 185 This new interpretation dispels the difficulties pointed out by Prof. Kendall, and justifies his suspicion that older rocks than ‘Oxford Clay were present., We may also now feel more confident than before that the Bletchley Boring, if it did not actually touch the Paleozoic floor, came extremely near to it; and we may safely assign to it a level a little deeper than — 150,° which is practically identical with that at Calvert. We may also infer that the Paleozoic floor, in the near neighbourhood, consisted of Charnian igneous rocks. 1 H. B. Woodward, ‘Jurassic Rocks of Britain’ Mem. Geol. Surv. vol. iv (1894) pp. 518, 515 & vol. v (1895) pp. 340, 341. 2 Final Rep. Royal Comm. on Coal-Supplies, pt. ix (1905) p. 25. 8 According to the engineer’s record, the well started about +260 feet, and the boring went toa depth of 410 feet. In the Royal Commission’s Report, and in ‘Jurassic Rocks of Britain’ Mem. Geol. Surv. vol. v (1895) p. 48, the depth is given as 419 feet. The former figure has been taken. 30+ DR. A. M. DAVIES AND MR, J. PRINGLE ON [June 1913, V. Tuer Pauazozoic FLoor norts or tHE THAMES. [A. M. D.] The time has come when it may be useful to take stock of the knowledge already gained from scattered borings as to the depth of the Paleozoic floor, and to express known facts and probabilities in the form of a contoured map. Where Triassic deposits rest upon it, this floor probably has the uneven form of a buried land-surface, much too irregular to be contoured from scattered observations ;. but, where marine strata directly overlie it, it is probably a smooth peneplain—either of prolonged subaérial or of marine denudation... Further, where Trias is present, its deposition must have levelled up. the irregular land-surface to another smooth plain. In short, the base of the marme Mesozoic (of whatever age, from Rheetic to Gault) must form a sufficiently continuous smooth surface to be contoured from its known outcrop to the depths at which it is met in borings. This is what has been attempted in Pl. XXXIV. Where Trias is. absent, the contours are those of the Paleozoic floor. On the same map have been indicated, as far as the scale would allow, all the mapped folds and faults in the Mesozoic rocks, andi the chief of those in the exposed Paleozoic rocks. These are of importance for a consideration of the possible tectonic structure of the buried Paleozoic floor, if that of its Mesozoic cover corresponds. to it in any degree. The danger of assuming too simple a structure in the buried Paleozoic floor is evident, if we consider the repeated series of earth-movements to which its constituent rocks may have been subject :— (1) Post-Tremadoe movements, indicated by the absence of Ordovician. rocks south-east of Shropshire ; (2) Post-Lower Devonian movements, indicated by the barrier between the Midland and South-Western Provinces, and the unconformable- sequence of Coal Measures on Lower Old Red Sandstone in South Staffordshire and elsewhere + ; (5) Repeated intra-Carboniferous movements shown by the zonal work of Dy. Vaughan, Dr. Sibly, and Mr. Dixon, by the overstep of Lower Carboniferous by Upper Coal Measures in the Forest of Dean,* and: by local irregularities in the Midlands; (4) Post-Carboniferous movements. The most striking example of continuity of tectonic lines from. the Paleozoic area into the Mesozoic area is afforded by the western boundary-fault of the Warwickshire Coalfield, which has a north-and-south or Malvernian trend. ‘This is carried on through the Trias of the Forest of Arden in the form of the easternmost 1 W. W. King & W. J. Lewis, Geol. Mag. dec. 5, vol. ix (1912) pp. 487, 488. 2 1. FB. Sibly, cbid. pp. 417 et segq. 3 ‘ The rocky floor upon which the Carboniferous rocks of the Midlands were deposited seems to have been greatly affected by the action of local crust-creep during Carboniferous time’: C. Lapworth & W. W. Watts, ‘Geology of the: Birmingham District’ Proc. Geol. Assoc. vol. xv (1898-99) p. 564. Vol. 69.| TWO DEEP BORINGS AT CALVERT STATION. 330: syncline and anticline mapped by Dr. Matley.!. Further con- tinuation of the anticline is suggested by the levels of the Liassie- outcrop near Stratford-on-Avon, and this is in line with the well- known Vale-of-Moreton Anticline. Batsford Boring, which proved Coal Measures on Silurian, is on the Valc-of-Moreton axis. West of the axis is the remarkable sag, proved in the Mickleton Boring, where the base of the Rhetic was at — 815 feet O.D., although 5 miles away to the north-east, 6 miles to the north-west, and 10 miles to the west the same horizon crops out at about + 100. As the levels of the Middle Lias are not recognizably affected, and the Lower Lias proves to have ‘the enormous thickness of 1241 feet, it seems likely that we have here a case of Liassic- faulting masked by contemporaneous sedimentation. The other side of the trough may be a line of Charnian trend in continuation of the Lickey axis. here are some slight suggestions of this (see Pl. XXXIV). Farther south of the same region, the Bajocian. flexures mapped by Mr. Buckman have a Charnian trend.” The strike of the Cambrian rocks on the eastern side of the Warwickshire Coalfield shows a variation between Malvernian aud. Charnian, between north-west by west and north by west. They have approximately the latter trend as they disappear underneath the Trias near Bedworth, and the Brandon Boring shows its con- tinuance to the latitude of Rugby.’ If we may consider the faults. in the Jurassic rocks near Harbury and Cropredy as a key to the structure beneath, the trend may have returned there to a Charnian direction, which, if continued, would carry the Cambrian towards. Bletchley, or with a subsequent return to Malvernian, towards. Calvert. In the Triassic area of South Leicestershire, inliers and borings. show the presence of a variety of Paleozoic rocks—unproductive Coal Measures, Millstone Grit, Carboniferous Limestone (Viséan),. Cambrian, and Charnian igneous rocks. Continuation of this mixed belt in a south-easterly direction is suggested by the Viséan of Kettering Road, Northampton, and the Charnian igneous rock of Bletchley. Lastly, the strike of Charnwood Forest leads to the Charnian igneous rock of Orton Boring. Thereis, however, a belt, at least 10 miles wide, curving round from Cheltenham towards North- ampton, in which the numerous faults are disposed athwart the supposed Malvernian-Charnian lines. South of this belt, a Charnian direction is again seen in the post-Jurassic pre-Cretaceous folds of the Swindon and Oxford-Aylesbury districts. In view of this. transverse belt, and the absence of any clear indication of a Charnian strike in the comparison of the two borings at Calvert, it would be very hazardous to assume the continuity of Warwick- shire conditions so far as Calvert. 1 Q.J.G.S. vol. Ixviii (1912) fig. 7, p. 270. 2 At Daylesford, on the eastern side of the Vale-of-Moreton Anticline, con- glomeratic marlstone with Palxozoic pebbles offers a problem for solution. See Hi. Hull, ‘The Geology of Cheltenham’ Mem. Geol. Sury. 1857, p. JOR also L. Richardson, Proc. Cotteswold Nat. F.-C. vol. xvii (1911) p. 200. 3 R. D. Vernon, Q. J. G. 8. vol. lxviii (1912) p. 611 & pl. xi (map). 336 DR. A. M. DAVIES AND MR. J. PRINGLE ON [June 1913, The question of greatest general interest suggested by the Calvert borings is whether productive Coal Measures may be present in that portion of the Paleozoic floor which they have shown to come so unexpectedly near the surface. The answer to this question must at present be very uncertain, and I would simply make the following remarks : (1) The Midland Coal Measures show evidence, by the coalescence of seams, attenuation, and overlap towards the south, that a barrier of older rocks must exist in that direction. The occurrence of pro- ductive Coal Measures at Burford (whether they are productive or unproductive at Batsford does not appear from the published state- ment) shows that by that latitude the barrier has been crossed. (2) Carboniferous Limestone is known to occur at Northampton, and, by inference from the pebbles in the Permian conglomerates,* also beneath the Forest of Arden or its neighbourhood. Its absence at Batsford, half way in a straight line between Northampton and the Forest of Dean, along with its overstep by Coal Measures between that Forest and the Forest of Wyre, renders it quite possible that in the Calvert area Coal Measures might rest directly upon the Cambrian recks. In this connexion it may be noted that the Lias of Calvert, while showing relations to that of the Radstock area in respect of its overlap, shows neither the attenuation nor the calcareous composition which are there associated with nearness to an extensive mass of Carboniferous Limestone. Further knowledge is needed before any definite conclusion as to the existence of Coal Measures can be reached; and the shallow ‘depth of the Paleeozoic floor makes that further knowledge com- paratively easy to obtain. Mesozoic Overlaps on the Paleozoic Floor. It may be useful to summarize here what is known as to the progressive submergence, with interruptions of partial emergence, of the Paleozoic floor of the South-East of England. (1) The Charmouthian overlap (hemere raricostati to jamesont) is now known at Calvert and at Brabourne; reasons have been given for believing it to exist at Bletchley also; and, from an examination of the Ropersole cores, it is thought that when the fossils are extracted and identified they will prove it there also. At Calvert there must have been a temporary submergence in the hemera rariostati, followed by a short emergence before the main gamesow transgression. Similar oscillations are known to have occurred in the Radstock area, where remanieé fossils of the rare- costatum zone are found at the base of the armatun zone in some places, though in others the former zone is present. At Vobster it rests upon the Carboniferous Limestone: elsewhere in the 1H. T. Brown, Q.J.G.S. vol. xlv (1889) p. 27 & table on p. 24 ; ye W. King, abid, yol. ly (1899) pp. 122, 123. Vol. 69.] TWO DEEP BORINGS AT CALVERT STATION, 337 tadstock area one or other of the lowest Charmouthian zones rest upon the obtusum or semicostatum zone of the Sinemurian. (2) A later Charmouthian overlap (hemera capricorni) occurs at Dover. (3) At Calvert and Oxford, and (if my interpretation be correct) at Bletchley, there is evidence of a post-Charmouthian emergence, causing the very marked non-sequence between at least a high zone of the Vesulian and the lowest zone of the Domerian. It would be interesting to know in what manner this gap gradually becomes filled up between Calvert and the outcrop in the Banbury district. Future borings may perhaps add much to our knowledge, and enable us to date with some precision alternate advances and withdrawals of the sea over this area. For the present, we only know that the non-sequence is split into two: for, while at Fritwell the Zrigonia-signata Beds rest on Upper Liassic Clay with Dactylioceras,' at Brackley the Upper Lias rests directly on the margaritatus zone.” This disappearance of the spinatum zone (which I suspect also at Stratton Audley and Stony Stratford from the published accounts®) is remarkable, in view of the fact that at Mells in Somerset the spinatum zone appears to overlap on to the Paleozoic.* When emergence in one area is thus contem- poraneous with submergence in another, it is evident that broad movements of the sea- Hevell cannot alone explain the facts: local crust-movements must have been taking place. (4) The repeated oscillations that produced the numerous non- Sequences in the Inferior Oolite do not appear to have left any trace in the Hast of England. Even the garantiana overlap, which iS so widespread in the West of England and touches the Palzeozoic at Nunney, did not reach as far east as Calvert. It was not until late in the Vesulian age that the area of deposition once more extended to that point: it may have reached Brabourne at about the same time. In neither place does it attain the Paleozoic floor itself; Vesulian rests upon Voarcian at Brabourne, upon Domerian at Calvert. (5) The Bathonian overlap (circa hemera bathonicw) upon the Paleozoic floor is known under London (at Meux’s Brewery), and at Richmond and Streatham. It may have been about the same time, or somewhat later, that Charmouthian beds were re-sub- merged at Bletchley. At Dover the date was probably earlier. (6) The Callovian overlap (hemera macrocephali), which is of so much importance abroad, is unknown in Kngland, if the old 1 J am indebted to Mr. J. Pringle for this information. 2 Tam indebted to Mr. E. A. Walford for this information in advance of publication. 3 H. B. Woodward, ‘ Jurassic Rocks of Britain’ Mem. Geol. Surv. vol. iv (1894) pp. 291, 495. 4 C. Moore, Q. J.G.S8. vol. xxiii (1867) pp. 980-81. 338 DR. A. M. DAVIES AND MR. J. PRINGLE ON [June 1913, interpretation of Bletchley is abandoned. On the contrary, it is. found at Calvert (and probably at Bletchley) that a non-sequence occurs between Oxford Clay and Forest Marble, as though the Cal- lovian age were a time of emergence. In this connexion it may be recalled that in various parts of the outcrop there is no evidence- of Callovian, while the anceps zone of the Continent is scarcely known in Britain.’ Along the outcrop, however, the Cornbrash is. one of the most constant of formations: its absence at Calvert was a great surprise. (7) No later Jurassic overlap is known, and the next is the Wealden overlap, known on the Paleozoic floor at Ebbsfleet only. At Dover, Wealden rests upon Kimmeridgian. (8) The Aptian overlap (hemera deshayesii?) occurs at Culford on the north and Cliffe on the south; also upon Jurassic strata at Richmond, Chatham, Bobbing, and Chilham. (9) The Albian overlap (hemera interrupt: or later) is shown at Harwich, Stutton, and Weeley, at Ware, Cheshunt, Kentish Town, and Crossness (and upon Jurassic strata at Saffron Walden, Meux’s Brewery, and Streatham). With this, the Paleozoic floor and its. Jurassic cover were in all probability finally submerged. Vi. Summary. The most important new facts recorded in the present paper are- these : (1) The shallow depth at which the Paleozoic floor lies at Calvert—4433 feet below the surface, or 1534 feet below sea-level. (2) The presence in North Buckinghamshire of Lower Tremadoc- Beds (Shineton Shales) with Clonograptus. (3) The absence of Triassic (except possibly in the Western. Boring), of Hettangian and Sinemurian, and the direct superposition of the Charmouthian (jamesoni zone) upon the Paleozoic floor. (4) The absence of all but the lowest portion of the Domerian (Middle Lias of the Geological Survey), of the whole of the Toarcian,. Aalenian, and Bajocian (Upper Lias and most of the Inferior Oolite), and the superposition of a high zone of the Vesulian. (Chipping-Norton Limestone) upon the algovianum (lower mar- garitatus) zone of the Domerian. (5) The absence of a portion of the Swerford Beds, the Nezran. Beds, and probably of a small portion of the Great Oolite. (6) The absence of Cornbrash and Callovian, the ornatum zone of the Oxfordian resting directly upon the Forest Marble. ' See S..S. Buckman, ‘Summary of Progress for 1911’ Mem. Geol. Surv. . 1912, pp. 62, 63. for) sp) aR) “OLOZORV T 6rOT— “OLOZOM[R FOOL — pet ate gee nae eg Se ay ACIEEINY VN “OLOZOBTR] 2601 — “DLOZOM] RT (Oca ee euee tos EEE TY SNES] ‘1a *‘DLOZOB RT C6FI — “OU vq PL6— Bag Sa Be ak ah ~ 1099N4G ‘0G . “yyy ce, — *‘payovat JON SE ipa aa eA CULO) ‘6L A “DLOZOR| VT type — *D10Z0a[ RT 57%G— bo Aaa See eee CONTIG) "ST a "(4 ULIPAOJXG) OIssB.n e FOR — “patpovat 40 Ny Si seaey Seae pe OD TOAN OARS “LT < “RT YOOT CA AA “Tt, — “UVEOOT UA AA, £9g9— Nake Roos BB AN ‘OL D “URIUMO A(T 006 — “URIMLOAA(T =o/Q— Sota ei UCase MN SOUT) ‘CL 4 dgjney 9001 — | ¢ parpova.t JON BODLEIAN DIS ONT EATON, PL ES *SAIMSLAT, [BOP tog — | [Avy aadnayy “SBI, WO poqteyg BTSs a ae ea eee eel O DUC GT "eT ‘a ‘aUOspuRG sadnayy eg, — “prey tadnayy OLI— Be ee pe eee CLG UUM ‘SI = URTUIR elp — “SULLT, 11e— sbbbpaBaeeaesSpoTToUnPcca Ho CG) ‘TI S a SBLUT, e6e Sa x a SULIT, 90¢— teens De te ee ee eee ee ad LOYISSULyy ‘OL S| ‘(Bast A) dUOJSOMIITT SNOTDFIUOG.Ae) ele — g SULLY, 09F— (peo Surt}j}0 3 ) WozduAeTg.10 jr 6 =F 'SuILy, | 6cFr — / MAU §, |p COP — __ Gears Gots) toyd wre 9.10 N 8 2 “OUOJSPURG pay Plo aIlZ — “LAB, tadno sp cee— —— W0F AB) “fh iS d URIUIBYS) Ost — d URIS d0¢T— PETS ee nd eae ee KOTUOLO TT 9 I URMOOPBUTAL J, 8011 — URIDOpRUat.y, SOG ia es Tag Ses RoSBEOON SH OSE9°S “ATBYAAD) ‘g i ‘(uRTyNowAeys?)) sevvy 676 — VATS OIESHE AKON 9 <= APeanemecaen negsrag Tne OAH EIA TONOND(G) P aI EOE CONS IES) 0901 — “SULT, + 198— co qausig plopung, € a] URLINTIG ogei— [lB todnayy ogi— LS 3 eee eS OTSN EA Ve A *[leyy tadne yy ars — ‘Vp todno yy elTg— PILE: vere OFA OLIAL ‘T ° BS ee AL =I ‘Z'O *210Z0SaTT “210Z08aTT ‘dong “payovad Worgpulof Jsamory noj)2q qaafw IUIADUL MN0]AQ amwnu fo asng fo "(Oo hq. pI0'T Pe yqdap 7seqnaty UO’ DULLO 0229 Jaaf ur yadaq NT "AIXXX SLVTq NI NMOWS SONIMOG dO aATAVY, Vol. 69. | 340 DR. A. M. DAVIES AND MR. J. PRINGLE ON [June 1913, The following are the chief suggestions of a more theoretical character :— (1) That the gas-bearing strata of the Western Boring are Triassic, the actual margin of that system lying between the two borings at Calvert. (The alternative possibility that those strata are Upper Paleozoic is considered.) (2) That in the Bletchley Boring Oxford Clay, Forest Marble, and Lower Lias are present. (3) A contoured map of the Paleozoic floor is presented, as a basis for future discussion. (4) Suggestions are made as to the structure and composition of the Paltozoic floor. EXPLANATION OF PLATES XXXIIT & XXXIV. Puarn XXXII. Microscope-sections of rocks from the Calvert Eastern Boring. Fig. 1. Bottom bed of Great Oolite, at 195 feet: x23. In the centre is a rounded fragment of oolitic limestone, with a coating of calcite, dusky marginally, and partly worn away. Derived oolite-erains with dusky margins are seattered through the matrix. (See p. 518.) 2. Sandy beds in Chipping-Norton Limestone, at 201 feet: x 23. In the centre is a subangular derived fragment of oolitic limestone with dusky margin. (See p. 319.) 3. Same beds: x 17. In the centre is an oolite-grain indented by angular quartz-grains ; around are oolite-grains and fragments, with dusky margins. (See p. 319.) 4, Olivine-basalt sill at 606 feet: x 20. Porphyritic olivine-pseudo- morphs in calcite, showing parallel growth and zonal inclusions ; groundmass with felspar-laths and minute opaque granules. (See 9. 326. dD. ee - the same sill: x 223. Margin on the right; across the centre a calcite-vein; the dark patch below this is probably an in- clusion of shale; olivine-pseudomorphs in calcite; felspar-laths- (See p. 526.) . Portion of the same: xX 90. Felspar-laths; vesicles (?) filled with chlorite ; groundmass. ; . ior) Prarn XXXIV. Map of part of South-Central and South-Eastern England, on the scale of 10 miles to the inch, or 1: 633,600. The contour-lines give the estimated Cepth of the base of the marine Mesozoic strata (Gault or Jurassic) above or below Ordnance datum. ‘To the south-east. of the dotted line (approximate south-eastern limit of Yrias) they are also contour-lines of the Paleozoic floor. The localities to which the numbers on the map refer are enumerated in the table on p. 339. ‘The figures at the side, if not followed by a letter, denote the depth below O.D. of the Palaeozoic floor immediately beneath marine Mesozoic strata; when followed by a_ , they denote the depth below O.D. at which marine Mesozoic strata rest upon Trias; when followed by a J, they denote the depth below O.D..at which the boring ended in Jurassic strata. Quart. Journ. Geo. Soc. Vor. LXIX, PL. XXXII. fi ‘et ve Aa: A Hay Bia 9 NY " Kent oan Cas wide Kan fy) Mie : Gu Raa This oh H.G.S., Photo. Bemrose, Collo., Derby. ROCKS FROM THE CALVERT BORINGS. quart. Journ.Geotl. Soc. Vol. XIX, PLYXIV. sl : -600) -700) ~800) = 3001 | ) O UT | | t VS ; ! i aeey } | “SCALE ; ————_ ! ! [ I Y | i | hp | / | | e | | Fae a 7 : E / y i | ‘ / a / a / i / / | ye y % ‘ é / i NO A us / i i / ‘ / Jk dombs(9)~735 + } < “4 \ / j 7 a ! / 02 el 3 | i / RY j / Fe if / aO- PNY xe STUTTON > ~EnY — } ~ ©, TER os “NE: & BLACKWAI ee an LSTUARY f jesse Contour_lines of the base of the marine Mesoxote. This ts identical with the Pal- zoxotc floor in thal part of the map trom which Triasis absent, that ts to Di the south east of Calvert. To the north ee west tts identical with the top of the Trias & not with the Palzxozovc floor. Quart. Journ.Geol. Soc Vol. LXIX, PU XXXIV Sapcote. fon, MAP OF PART OF SOUTH-CENTRAL AND SOUTH-EASTERN ENGLAND. Freeholt s ‘ 3 ON THE SCALE OF [0 MILES TO THE INCH, OR 1:633,600. StafFs : Bate Warwickshire Coal- Coalfield . 0° BRANDON hs 4 8 a Rugbyfi2 +10 7. Hera Kingsthorpe _— ‘S06T- “Harthamtae SS Coombs (9)-735 + a Gavton®235 Saffron Walden @-B040P STUTTON ©- BLETCHLEY oo a WEELEY @)-1039 WARE()-686 ‘aURFORD@) #897 ~~ contour-lines of the base of the marine Mesoxoic. Uhis ts identical with the Pal J woroic flour in that part of the map aac ae, trom which Trias is absent, that isto SHAE) eo f __Anticline the south east of Culvert. Te the north “00° ee a west tl ts tdentice with the top of the —}—__ §) | Trias & not with the Palwozove Floor Intra-Jurassic Folds LLG a eae Vol. 69.] TWO DEEP BORINGS AT CALVERT STATION, o4l Discussion. The Secrersry read the following letter, received from Mr. S.. D ’ S S. Bookman :—— ‘The discovery that at Calvert the ornatwm zone rests directly upon Forest Marble is very interesting, because immediately south of Calvert the road to Hdgcot passes over a knoll of Cornbrash, which forms a conspicuous feature with a steep hill overlooking the village of Edgcot. There must be a con- siderable area of Cornbrash here, and the characteristic rock with brachiopods is exposed by the roadside north of Edgeot ; but this inlier of Cornbrash is not marked on the Geological Survey map. It is the eastern extension of the line of inliers of Cornbrash which extends from Islip to Ambrosden and to Marsh Gibbon. ‘The Cornbrash of Hdgcot must be about 100 feet above the base of the Ornatus Olays of Calvert, and so there must be a fault to that extent just south of Calvert Station. ‘Tt is interesting to note that beds missing on the downthrow side of a fault are preserved on the upthrow side. The case is exactly parallel with that of the Peak Fault in Yorkshire. The explanation would seem to be that the original axis of the anticlines lay to the north, and that the denudation of the anticlinal folds—in the Calvert case pre-ornatum, in the Peak case pre- murchisone—was accomplished long before the present fault-lines were developed,’ Mr. G. Barrow drew attention to the persistence of the bright green clays in the Forest Marble Group, and asked whether the Authors had ascertained if these clays had been met with in the deep borings under London. Mr. L. J. Wrxts enquired of the Authors the distance between the two boreholes, in view of its bearing on the possibility of the occurrence of Trias, as suggested by them, in the western one. Dr. J. V. Exsppn commented upon the description of tue absence of Kellaways Rock and Cornbrash in the borehole as a non- sequence, and asked what this term implied. Did it mean non- deposition, contemporaneous erosion, overlap, or what? With regard to the Bletchley Boring, the speaker believed that Charnian rocks occurred here immediately below the Mesozoic, the thick Shineton Shales shown at Calvert being apparently absent, and he asked whether the paper threw any light upon this question. Dr. C. A, Martry alluded to the great interest of the discovery of Cambrian rocks in the boring, and the close lithological resem- blance of these Tremadoc shales with those of Shineton, Malvern, and Merivale, The compound oolitic grains in the Jurassic lime- stones shown in the lantern-slides exhibited, reminded him of those from the (pre-Cambrian) Cemaes limestones of Anglesey, described and figured by the late J. F. Blake in the British Association Report for 1888. They seemed to the speaker to yield no proof of contemporaneous erosion, but to be recently-formed grains which had become agglutinated as they were moved about by marine currents, and then. coated by further layers of carbonate of lime. Mr. W. H. Booru asked whether the Authors had obtained any 342 TWO DEEP BORINGS AT CALVERT SLATION, [June 1913, measurement of the general direction of dip which, if of no imme- -diate use, might be of value in connexion with future observations of a similar nature. Dip-observations taken in a stratum several ‘hundred feet thick would surely escape some of the worst effects -of mere local dip and folding. He also suggested some regularly organized system of keeping motes of, at least, all special or deep boreholes, urging the need for educating the workmen in the importance of accuracy. The Presrpent (Dr. A. Strawn) said that he had watched this ‘boring, almost from its commencement, with great interest. He ‘reminded the Fellows that a report that coal had been found in it ‘had been widely circulated; but that the discovery of Clonograptus in the supposed Coal Measures had led to a reconsideration of the evidence on which the report was founded. It was most satis- factory that, by combining the information obtained by Dr. Davies with. that obtained by Mr. Pringle, acting for the Geological Survey, -a reliable account of the strata had been produced. The question of registration of boreholes, mentioned by a “previous speaker, was one to which he hoped to e¢all attention shortly. The recommendation made by the Royal Commission on Coal-Supplies had so far led to no practical result. Mr. J. Privete said that the conspicuously green clay which -occurred in the Forest Marble at Blackthorn Hill had proved recognizable in the Calvert Boring, and had served as a trust- worthy index. He had to thank Mr. Barrow for calling his atten- tion to its importance. Healso thanked the Fellows for the cordial xeception which they had given to the paper. Dr. A. M. Davrus, in reply, said that Mr. Buckman’s contri- bution was of the greatest importance, and might lead to modifi- cations of view as to the tectonic structure. He replied to Dr. Matley ‘that he had considered the possibility of some of the structures -shown by the oolitic rocks being due to contemporaneous erosion rather than to derivation from older rocks, and had decided that ‘this could not be so in all cases, though it might in some. To Mr. Booth he replied that Mr. Hiorns had endeavoured to ascertain the direction of dip; but the preliminary experiments carried ovt in order to determine the possible deviation of the borehole had een unsuccessful. He considered that the time had not yet come for attempting to make a geological map of the Palzeozoic floor. Vol. 69.) §GHOLOGICAL HISTORY OF THE MALAY PENINSULA. 343 17. Tae Grotoeicat History of the Matay Puninstna. By Joun Brooke Scrivenor, M.A., F.G.S., Geologist to the Government of the Federated Malay States. (Read January 8th, 1913.) [Puare XXXV—Map.] ContTENTS. Page I. Introduction........ See OS oichae GSB OSAO BERNE CUB EO OBE Oo nc EeRE Une CREA NnD irae iar 343 Mee rese mtr C Oni Cums Oly foutsacaciat stele cele cideswae f- ue atecseseaeesereed #6 345 . III. Brief Sketch of the Geology of the Peninsula ....................0....2. 348 HAVER MMe mt Ba Ub SELLS toi sie esis sieungen yleaduanr vow qunedodens suman ya meemeae ole D4A9 RMN Oierb Serics wiih .uukareee Sy zclits. tus ewe, re: Meusunat tuk, 349 RaeeWiroKGomclmanarOCks ve: cnuendtacecee sccucckoctcrse sacs ecamauuwess cusdlee as 349 Vallee incwzaAlnanceViolcamicy Seles macreennceneecae sates ener cer secesne me O VIII. The Mesozoic Granite..........-..... ae ae igais an etaide aiterie mi aieats Me Maem ac ee eco! 351 Xen ewe rtianvsConlsMleasuesmsa-cieen son een assis leamect-e aeeenaten seee cer ces EOL X. Fixed Geological Horizons in the Malay Peninsula .................. 352 IL, Wag Enionnlin Oil) Wlellny TBeranbaleM ey coe 5H5: obobconeceose oponpocuonsenoes: 357 XII. Special Points in connexion with the Benom Anticline ............... 360 XIII. Tertiary and Recent Changes in the Peninsula ...................0008. 362 XIV. The Formation of Lignite in Limestone-‘ Cups’ ................0.0.0 02 365 PRA lornential Dep Osutshsaccten st a: ces eceaceasieas: waasaeuengecien ete cctawesanae« 364 PNGVPIEME on ClUISH Oma Seo ee nace neice ty Le de onictins tment se ubekinatauealncc)) blame ect 365 I. Lyrropvction. Since 1903 a few papers have been communicated by me to this Society and to the ‘ Geological Magazine’ on special points of interest that have been encountered during field-work in the Malay Peninsula, and a number of local publications have appeared in the Federated Malay States, either in the Government Gazettes or as pamphlets issued by the Government Printing Department.’ These 1 (1) ‘Note on the Sedimentary Rocks of Singapore’ Geol. Mag. dec. 5, vol. v (1908) pp. 289-91. (2) ‘Note on the Igneous Rocks of Singapore, &e.’ Zbid. vol. vi (1909) (3) ‘ Obsidianites in the Malay Peninsula’ Jbid. pp. 411-18. (4) ‘ Radiolaria-bearing Rocks in the Hast Indies’ Zbid. vol. ix (1912) pp. 241-48. (5) ‘The Lahat “Pipe”... in Perak’ Q. J. G.S. vol. Ixv (1909) pp. 382-89. (6) ‘The eons -Corundum Rocks of Kinta?’ Ibid, vol. Ixvi (1910) 455-4 (7) The Rocks of Pulau Ubin & Pulau Nanas’ Jbid. pp. 420-34. (8) ‘The Gopeng Beds of Kinta’ bcd. vol. Ixyiii (1912) pp. 140-63. Among the local publications are the following :— (9) “The. Geology & Mining Industries of. Ulu Pahang,’ with a geological sketch-map. Kuala Lumpur, Government Press. 1911. (10) ‘The Geology & Mining Industry of the Kinta District, Perak,’ with a geological sketch-map. Kuala Lumpur, Government Press. 1913. OriGs ss No274. 24 344 MR. J. B. SCRIVENOR ON THE [June 1913, local publications deal with restricted areas, and are, moreover, difficult of access to those who wish to study the geology of the Peninsula. I think, therefore, that an attempt to communicate to the Society in a connected form such evidence as has been obtained since 1903 of the geological history of the Peninsula, but without going into much detail, will not be out of place. The nature of the work carried on since 1905 has been economic ; but, as is well known to field-geologists, it 1s impossible when engaged on such work to close one’s eyes to a mass of interesting information that may have no direct economic bearing, and it is this information that is now presented. It is necessary to add that I make no claim to have completed a survey of the whole Peninsula; in fact, detailed geological surveying has been finished in two portions of the Peninsula only: namely, Ulu Pahang and the Kinta District of Perak, while Mr. William Richard Jones com- menced the detailed survey of Selangor this year. Nevertheless, sufficient evidence has been gained in the last nine years to give a very fair idea of the outline of the geological history of the Peninsula. It is not preposed to enter here into any lengthy discussion of the previous literature dealing with the Malay Peninsula. I have mentioned it elsewhere (Nos. 9 & 10 in the bibliographical list on p. 343). The most remarkable point about it is the almost complete unanimity with which mining engineers and others have given the sequence of the rocks in an inverted order. I must, however, express my gratitude here for valuable assistance in the form of publications on paleontological subjects, to be mentioned later, by Mr. R. B. Newton and the late Prof. T. R. Jones; and also for examination of paleontological material by Dr. A. 8. Woodward, Mr. G. C. Crick, Dr. G. J. Hinde, and Mr. H. N. Ridley. Of literature dealing with countries adjacent to the Malay Peninsula, and that one has to consider in connexion with the geology of the Peninsula, there is much that is of the greatest interest. Some of this—such as the publications of the Geological Survey of India and the ‘ Manual of the Geology of India’—is well known ; but J would especially emphasize the value of the lttle- known though beautifully-executed geological maps of parts of the Dutch East Indies, the result of the work of Dutch geologists, whose memoirs are to be found in the scientific parts of the Jaarboek van het Mijnwezen in Nederlandsch Oost-Indié. The most important publications, apart from this annual, are the results of Prof. Molengraaff’s explorations in Central Borneo? and Messrs. Verbeek’s & Fennema’s ‘Geology of Java & Madura.’ It is unnecessary to give a complete list here of the literature published by workers in the Dutch East Indies bearing on the geology of the Peninsula. » «Geological Explorations in Central Borneo’ English revised edition, London, 1902. Vol. 69.] GEOLOGICAL HISTORY OF THE MALAY PENINSULA. 345 Il. Presenr ConFiGuRATION, The Malay Peninsula and the Malay Archipelago form together ‘a very Interesting portion of the earth. To quote Prof. Suess ':— ‘ We have now arrived at one of the most instructive parts of the earth’s surface. Four elements combine to form it: the end of the Burman are, the southern branches of the virgation of the Philippines, the spurs of the great cordillera of New Guinea, and, finally, the continent of Australia with the cordillera which marks its eastern border and crosses Torres Strait.’ Of the Malay Peninsula itself, Suess says (op. cit. p. 231) :— ‘Fresh conlisses make their appearance in the south, and form the Malay Peninsula.... In this way the mighty swell of the Altaides in Thibet subsides and is dispersed. The whole continent becomes lower. Many ‘coulisses disappear. Only a few long branches are continued : on the east into ‘the cordillera of Annam; on the west, always giving rise to fresh coulisses, through the Malay Peninsula, and still further, to Java and beyond.’ Again (op. cit. p. 233):— ‘East of this [Bandon] valley rises the second granite coulisse, likewise ‘tin-bearing. It emerges from the sea in the island of Koh Tau.... forms ‘the hilly islands, Koh Pungum and Koh Samul... , and entering the Peninsula becomes the Lakawn range, which thence onwards represents the axis of the Peninsula. Still further south this long granite range breaks up into isolated ridges and, associated with ancient sediments, reaches the sea near Singapore. A series of cliffs and smaller islands reveals its continuity with the tin- producing islands of Banka and Billiton,’ Unfortunately, the material on which Prof. Suess’s description is based is somewhat out of date, and consequently it 1s impossible to agree with every point of it. I have dealt with the question of the ‘ancient sediments’ elsewhere, in connexion with another publication.” There is good reason to believe that the Lakawn (or Nakawn) Range is distinct from the axis of the Peninsula ; and the ‘long granite range’ that forms this axis can hardly be described as reaching the sea near Singapore. The accompanying sketch-map (Pl. XXXV) shows diagram- matically the chief structural features of the Peninsula; and, ‘although the States of Johore, Kelantan, Trengganu, and the country between Kelantan and Singgora are of necessity left almost entirely blank for want of information, it will be seen that the greater part of the Peninsula has been covered. Near the top of the map a range of hills will be seen trending northwards from near Aior Star to Singgora. This range, which has no distinctive name so far as I am aware, may be conveniently referred to as the Kedah-Singgora Range. West of it the country is low-lying and traversed by an earth road, by which one may ‘travel from Alor Star to the China Sea. This Kedah-Singgora Range, composed of quartzite and shale, may be regarded asa barrier cutting off the Peninsula proper from the Isthmus, and it is ‘to the east of this range that the great main granitic axis of the 1 «The Face of the Harth’ vol. iii (1908) pp. 281-32, English translaticn. * Geol. Mag. dec. 5, vol. vi (1909) pp. 330-32. Za 2 346 MR. J. B. SCRIVENOR ON THE [June 1913, Peninsula and its branches have their origin. The Kedah-Singgora Range consists of hills of no great altitude. Exact measurements, I believe, have not been made; I doubt whether any of, the summits reach 1000 or even 800 feet above sea- level. The beginning of the main granitic axis is shown on the sketch-map (Pl. XX XY), and the range is traced between Kelantan and Perak, Pahang and Selangor, into Negri Sembilan, where it breaks up into smaller ranges. This granitic axis will be referred toas the Main Range. In the north the Main Range is as yet imperfectly known. 1 have marked it on the map as though it were a broad granite- outcrop; but my own notes in Upper Perak prove that the granite is associated with other rocks, such as crystalline limestone and wollastonite-schist. The sketch-map must uot, therefore, be taken as indicating in this part of the Peninsula one unbroken granite- outcrop, but rather as showing the area over which granitic out- crops form important structural features. Branching off from the Main Range near its commencement are. granitic outcrops that end in the granite of Penang. These outcrops form hills in Southern Kedah and in Province Wellesley. They are not connected one with the other, so as to form an unbroken chain of mountains. Kedah Peak is another granite-mass. In the upper waters of the Krian River the granite of the Main. Range forms great mountains, behind which are other granitic peaks in tie north e Perak. One well-defined spur, however, comes down in a south-south-westerly direction, forming the eastern boundary of the Larut District and ending in the granitic hills of the Dindings.. Another spur is given off from the Main Range between the ‘Perak and Kinta Rivers, known as the Kledang Range. In the south of Kinta the Bujang-Malaka granite-mass marks a westward protrusion of the granite of the Main Range; and there 1s. some evidence that this granite-mass may be connected with the granite of the southern part of the Kledang Range, at no great depth from the surface. ( Another protrusion of granite from the Main Range juts out. towards the centre of § Selangor. The hills formed by this mass end at Rawang, but small intrusions of granite are known on the west. and an isolated granitic hill occurs at Kuala Selangor. Intrusions of granitic rocks are known on the coast of Negri Sembilan and Malacca. These may be regarded as the last out— crops of the granite of the Main Range. Another isolated granite-hill is found at Jugra in Selangor. Its relation to the Main Range is at present sania teturning to Perak, we ind between Krian and Larut an isolated range of quartzite, conglomerate, and shale, the Semanggol Range ; and quartzite-hills are found near Telok Anson. In Selangor such hills form a large part of the State. On the east of the Main Range, I have little first-hand in- formation from Kelantan, but the hills in the large State of Pahang yr 1 ; Vol. 69. ] GEOLOGICAL HISTORY OF THE- MALAY PENINSULA. O47 are well known tome. At the foot of the Main Range is a chain of quartzite-, conglomerate-, and shale-hills that I have called elsewhere the ‘Main Range Foothills” These are almost certainly eontinued northwards into Kelantan, and enter Negri Sembilan in the south. Travelling eastwards from these Main Range Foothills, one en- counters a huge isolated range of hills, the Benom Range, com- posed of mica-granite, hornblende-granite, and syenitic rocks. Small granitic outcrops on the River Tanun mark the dying away of this range to the north; and on the south similar outcrops are tound extending into Negri Sembilan. Mount Ophir, in Johore, near the Malacca border, may prove to be a southern prolongation of the Benom granite. ’ Hastward again from the Benom Range and to the east of the Pahang River is a great belt of hilly country, composed of quartzite, conglomerate, and shale, that extends northwards into Kelantan and southwards into the Rumpin Distriet. The trend of the hills points directly to Singapore, where similar rocks are exposed; and it is believed that these Singapore quartzites, etc., and the Pahang quartzites are connected by outcrops in Johore. It is impossible to speak more definitely at present on this point, but a traverse along the greater part of the Johore Railway left little doubt as to what may be expected when further research ean be undertaken in that part of the Peninsula. This belt of hills east of the Pahang River may be described conveniently as the ‘ Main Gondwana Outcrop, for reasons that will be given later. It is for the most part composed of hills of no great altitude: in the north of Pahang and the south of Kelantan, however, the outcrop is bounded on the west by the Tahan Range, composed of the same rocks, but containing the highest peak in the whole Peninsula, Gunong Tahan. (Gunong Tahan is 7188 feet above sea-level; Gunong Riam, or Kerbau, the highest peak in the Main Range, 7160 feet; Gunong Benom, m the Benom Range, 6916 feet.) East of the Main Gondwana Outcrop in Pahang and Kemaman are more granitic ranges; and the island of Tiuman in the China Sea is built up of granite, with some highly-altered sedimentary rocks. Apart from these granitic and quartzitic ranges, there are in the Peninsula numerous limestone-hills with precipitous sides that afford most interesting evidence of the past history of this part of the world. They are not marked on the map, except Gunong Geriang in Kedah; and it is sufficient to say that the greatest development of them is found in the Kinta district of Perak. There are several limestone-hills in Pahang, some being of great size. The western coast of the Peninsula is mostly low-lying mangrove- swamp, extending in some parts for many miles inland and broken by occasional sandy beaches, isolated granite-hills, and small isolated quartzite-hills. Much of this low-lying tract has been reclaimed, and furnishes very fine agricultural land. 348 MR. J. B. SCRIVENOR ON THE (June 1913, The eastern coast also is low-lying, but more sandy than the west,. and from it, too, isolated hills spring up like islands. In the Straits of Malacca there are a few rocky islands, distinct from the large mangrove-covered islands such as those that fringe parts of the coast of Perak and Selangor. In the China Sea numerous rocky islands, of which Tiuman is the largest, lie close to the coast. Ill. Beier Sxercu or tar Geotocy or THE PENINSULA. Anyone who has read some of the earlier works on the tin- fields of the Peninsula would naturally conclude that the superficial recent deposits are of great importance. This, however, i3 not the case, owing to the fact that the Peninsula is now experiencing a long-continued period of uplift, which has prevented any great accumulations of alluvium in the valleys. Weathered rocks z. situ, soft granitic rocks rich in kaolin, and Paleozoic clays have been described erroneously as alluvium, and we can confine our attention almost entirely to the solid geology of the country. A. brief sketch of this now will make subsequent sections more easily understood. The oldest-known rocks in situ are a calcareous series, named provisionally the Raub Series, with which is associated in Pahang the Pahang Volcanic Series, partly contemporaneous with the Raub Series, but continuing into later times. ‘The Raub Series. forms a large part of the lower-lying land of the Peninsula, where the rivers have cut down to it through superincumbent rocks. A series of radiolarian cherts and fine-textured shales is believed to. be a phase of the Raub Series. Unconformable to the Raub Series is a great development of littoral rocks—quartzite, conglomerate, shale, clay-slates, and phyllites formed by metamorphism of the shales. Some rocks of the Pahang Volcanic Series are contemporaneous with part of them. In the Kinta district of Perak, and in other localities, at the base of these littoral rocks is a considerable thickness (about 200 feet where best preserved) of stanniferous clays with boulders, believed to be of glacial origin. The quartzites, etc. form a large part of the hilly country of the Peninsula, and they, together with the glacial clays, will be referred to collectively as the Gondwana rocks. Intrusive into the Raub Series and the Gondwana rocks is the granite of the ranges enumerated above, with other associated plutonic rocks. No granite in situ in the Peninsula is known to be older than the Raub Series and the Gondwana rocks; but in the glacial clays, the tuffs of the Pahang Volcanic Series, and the conglomerate of the Gondwana rocks, there is evidence of a much older granite: that was stanniferous like the younger granite. The granite that is older than the Raub Series, etc., and not yet known ww situ, is referred to as the Paleozoic Granite; the younger granite: is referred to as the Mesozoic Granite. Vol. 69.] GEOLOGICAL HISTORY OF THE MALAY PENINSULA. 349 Later than the Mesozoic Granite, and unconformable on the Gondwana rocks, are some Coal Measures of Tertiary age which crop out in Selangor. Dykes of dolerite which cut the Mesozoic Granite are believed to be of Tertiary age also. The only recent deposits that will be dealt with here are deposits of lignite and sand overlying glacial clay and limestone in Kinta, as also some interesting torrential boulder-deposits. IV. Tue Raves Sertiss. The Raub Series is calcareous throughout, but for a few shales that do not effervesce with acids, and is best seen in the valley of the Pahang River and its tributaries. It comprises limestone and shales with a greater or less percentage of lime, and there is reason to suppose that some of the shales contain a certain amount of very fine voleanic ash, which betrays itself by a buff coloration, while the ordinary shales are deep greyish-blue. Some of the shales contain carbon. The limestones range in colour from white, through grey, to black ; occasionally they are reddish. ‘The black limestones contain carbon in quantity. Even in cases where organisms can be easily distinguished, the limestones are to a large extent crystalline. On the west of the Main Range the limestones are markedly crystalline, and only crinoid-stems and other obscure fossils have been noted. In the Kinta Valley the limestone is exposed as well as could be desired in the limestone-hills, and in the mines in the floor of the valley. In some places it also rises as smooth-surfaced pinnacles above a thin layer of soil, and in the pinnacles evidence has been found of disturbances on a large scale. The only point that need be noted here, concerning the alteration of the limestone by the Mesozoic Granite, is the rarity of tourmaline as a product of metamorphism. V. Tas Cunrt SERIES. I need not repeat here the description of this series given in the ‘Geology & Mining Industries of Ulu Pahang’ (pp. 35- 37) and in the ‘ Geological Magazine.’* The most important point to notice is that the available evidence shows an unconformity between the Chert Series and the Gondwana rocks.” VI. Tar Gonpwana Rocks. Apart from the glacial clays, these rocks are best seen in Pahang, where fossils have been found near Kuala Lipis and on the Benta-Kuantan road, but fossils have also been found in Perak and Singapore. At first, these rocks were called provisionally the ' «Radiolaria-bearing Rocks in the East Indies’ Geol. Mag. dec. 5, vol. ix (1912) pp. 241-48, 2 Thid. p. 244. 350 MR. J, B. SCRIVENOR ON THE [June 1913, Tembeling Series. They consist of conglomerate, quartzite, grit, shale, and clay-slate. The two first-named rocks contain pebbles of radiolarian chert. The quartzite is very largely weathered back to sandstone, and the ‘ Myophorian Sandstone’ described by Mr. R. B. Newton belongs to this group.? There is not much to add here to the description of the Malayan glacial deposits given in my paper on the Gopeng Beds. They have been traced northwards and southwards outside the Kinta District, and are now known to cover a large area... ‘There is one important addition to be made, however, and that. is a-continuation of my remarks (on pp. 157-58 of the paper just mentioned) regarding the relations of the corundum-boulders in the glacial clays on the east side of the Kinta Valley to the tourmaline-corundum rocks found on the west side. Lvidence has now been collected, showing that the similarity noted by Mr. W. M. Currie, of the clays containing the tourmaline-corundum rocks with glacial clays, is supported by facts ; while my first notion, of the tourmaline-corundum rocks and the containing clay being the remains of much-weathered schists, can no longer be maintained. Now that the survey of Kinta has been completed, it is found that this earlier view involves hopeless difficulties. For instance: if bedding in the clays over the limestone on the east is preserved, why is it not preserved in the clays over the limestone on the west? The limestone is similarly affected by ground-water in both areas, and there is no evidence to show that there has been a greater sinking movement of clays over it in one area than in the other. ‘The inevitable conclusion is that bedding neyer existed in the western clays, and that they really are, what they seem to be, glacial boulder-clays. his question of the relation of the eastern and western clays is discussed fully in the memoir on the Kinta Valley now in the press. VII. Tur Pawsne VoLcantc SERrins. This series of volcanic rocks is widespread in the interior of Pahang, west of. the Main Gondwana Outcrop. Only a~iew occurrences are recorded outside Pahang. It has not been studied very minutely as yet, but enough is known to say that it is composed of lavas and ashes and perhaps of hypabyssal masses. The rocks - comprised in the series are quartz-porphyry, porphyry, granophyre, dacite, andesite, augite-andesite, and dolerite. They are frequently sheared and metamorphosed near the granite-junctions. I have already described the alteration of the dacites and dacite-tuffs of Pulau Nanas, near Singapore, by the Mesozoic Granite. The greater part of the eruptions that produced these rocks were submarine. 1 «On Marine Triassic Lamellibranchs discovered in the Malay Peninsula’ Proc. Malac. Soe. vol. iv, pt. 3 (1900) Pp. 130-39. 2 Q. J. G.S8. vol. Ixvi (1910) p- 48 5 Ibid. pp. 427-28. Vol. 69.] GEOLOGICAL HISTORY OF THE MALAY PENINSULA. 301 VIII. Tue Mesozorc Granite. All the granitic ranges of the Peninsula are, so far as is known, remnants of approximately contemporaneous intrusions. The available evidence points to the date of intrusion as having been at some time after the Trias and before the Hocene, perhaps between Inferior-Oolite and Cretaceous times.’ Most of the granite contains large porphyritic felspar-crystals, but some is non-porphyritic. There is no reason to suppose that this difference marks any important distinction with regard to the epoch of intrusion. The only other point in the petrology of the granite and asso- ciated rocks to be noted here, is the fact that the Benom Range differs markedly from other granitic ranges in the. Peninsula. In the Main Range, for instance, hornblende occurs sparingly, sometimes in quantity; but, in the Benom Range, the rocks that are known are mostly hornblende-granites and syenites. Ordinary granite is known to occur, however. Porphyritic crystals of felspar are found in the hornblende-granite, as in the granite of the other ranges. IX. Tue Tertiary Coat Measures. The Tertiary Coal Measures were found in Selangor in 1908. The credit of the discovery belongs to a Malay, who was prospecting for tin-ore by means of shallow pits, and found instead a seam of coal that proved later to be 40 feet thick. ‘The Coal Measures were inapped as well as circumstances allowed—they occur in the ‘densest virgin-jungle where there are no large streams, but plenty of swamp—by the difference between the soil formed by the Coal Measures and the soil formed by the quartzite and clay-slate on which they lie. But for an extension into swampy ground, where, of course, geological mapping was impossible, prospecting work by means of bores has shown that the limits of the Coal Measures thus indicated were fairly correct. They cover about 2 square miles, and are a remnant preserved on a low watershed from denudation. The coal is of poor quality, being on the border-line of the coals and lignites; and, if the fixed carbon or calorific value be taken as the basis of classification, it should be termed a ‘lignite.’ It might equally well be termed ‘pitch-coal’ or ‘sub-bituminous coal.’ Some of the shales have been found to contain a small quantity of oil. A number of fossil leaves have been collected from the shales, which Mr. H. N. Ridley, F.R.S., kindly examined for me. Like the flora of the Borneo Coal Measures, they resemble existing jungle types. The only shells found so far are some crushed specimens that are probably assignable to Heliw. The evidence for the Coal Measures being Tertiary is that they are unconformable on the greatly-disturbed quartzite and clay- slates; also that they show no trace of alteration by the granite, intrusions of which, with tin-ore, into the quartzites and clay-slates U See Q. J. G. S. vol. lxvi (1910) p. 429. 352 MR. J. B. SCRIVENOR ON THE [June 1913, occur not far from the Coal Measures. The high percentage of moisture in the. coal also (about 20 per cent.) points decidedly to its deposition at a later date than the granite-intrusion and the earth-movements that occurred when the granite was intruded. Reference to Dr. Th. Posewitz’s ‘ Borneo: its Geology & Mineral Resources’ [English transl.] 1892, will show that the plant-remains, although they support the other evidence of Tertiary age, do not help us in determining to what part of the Tertiary Era they should be referred (pp. 201, 224, 225). Van Hooze, however, has based an arrangement of Bornean coals on the percentage of moisture, thus (op. cit. pp. 219 & 220) :— IHIOGEMEY (tosses 4 to 6 per cent. of hygroscopic water. Oligocene ......... 9 to 14 do. do Miocene ............ 19 to 25 do. do. The idea of gradual dehydration underlying this arrangement is obvious. The Selangor Coal Measures, on this test alone, would be considered Miocene; nevertheless, the conclusion must be supported by other evidence before it can be accepted as satisfactory. X. Frxep Grotocicat Horizons 1x THE Misnay PENINSULA. Before going farther, it is necessary to discuss what evidence there is of fixed geological horizons in the Peninsula on which a description of its history can be based. Taking the calcareous Raub Series first, the paleontological evidence is not very satisfactory. Fossils from limestone in Pahang have been referred by Mr. G. C. Crick to Orthoceras, Cyrtoceras,, Gyvroceras, and Solenocheilus. Mr. R. B. Newton wrote to me concerning these limestone fossils :— ‘Hence the rocks may be recognized as of Carboniferous age.’ Imperiect casts and impressions of fossils are not uncommon in the weathered calcareous shales, but at one locality only, in Pahang, have any been collected that are of homotaxial value. Concerning these, Mr. Newton wrote :— ‘...,. The fossils themselves are badly preserved, being little more than impressions, and therefore are not sufficiently defined for illustration and detailed description. The most prominent are those having a circular or elliptical outline, which Mr. G. C. Crick determines asan Ammonoid resembling Waagen’s Xenodiscus. There are also some straight tube-like organisms which appear to be closely allied to Dentaliwm herculeum of de Koninck, The association of these two fossils is interesting, since similar forms are found together in the Upper Productus Limestone of the Salt Range, India, a fact which would favour the Malay specimens being of Permian age. ‘There are a number of other organisms, but very much too obscure for determination, among them being an Aviculopectinoid impression and some possible brachiopod remains. ‘Both Mr. Crick and I think these fossils younger than those referred to by Prof. Hughes as Permo-Carboniferous, in his notice of specimens from Malaya collected by the “Skeat Expedition” (Rep. Brit. Assoc. Glasgow, 1901, p-414) on account of the presence of a trilobite determined as Proetus.’ With regard to the fossils collected by the Skeat Expedition, Vol. 69. | GEOLOGICAL HISTORY OF THE MALAY PENINSULA. 353) I do not know their exact locality, nor have I seen the rock that contains them. In the report quoted, Prof. McKenny Hughes says. that the rock is almost entirely composed of silica, but that there must have been originally much carbonate of lime. We see, then, that the few fossils found point to the Carboni- ferous age of certain limestones and the Permian age of certain shales. But the field-evidence in favour of the limestones and shales. belonging to one series is so strong, that we cannot accept the paleontological evidence without qualification. The fossils found so far, in fact, have done no more than give a hint as to the age of the rocks: they may be Carboniferous or Permo-Carboniferous. Other evidence, unknown at the time when the fossils were de- scribed, make 1t improbable that they are Permian. It is interesting to note that, in Sumatra, Dr. Verbeek has. described Musulina limestone that is Carboniferous, as well as. ‘Culm.’ Wing Easton * also described ‘Culm’ and Carboniferous Limestone in the Toba District. Prof. Rothpletz® describes at length fossils from Permian rocks in Timor and Rotti. In Indo-China, pale-grey Permo-Carboniferous limestone is found in Upper ‘ongking,‘ and Upper Carboniferous and Lower Permian deposits in Tongking.’? M. N. Mansuy, again, describes. fossils from Permo-Carboniferous limestones in Indo-China.° There is no horizon in the Raub Series, then, that we can regard as fixed; but immediately above this series, in Perak, come the glacial clays, which furnish a more valuable horizon on climatic evidence than can be afforded by limited collections of fossils in rocks far removed from Europe. It is but reasonable to suppose: that the great climatic change that took place towards the close of the Paleozoic Era affected what is now India, South Africa, and Australia simultaneously, as geological time is measured.’ The Malayan glacial beds, then, may be correlated with the glacial beds at the base of the Salt-Range Productus Beds, with the Talchir Group at the base of the Gondwana Series, and with the Austrahan and South African glacial deposits. For purposes of correlation with deposits in these countries the Malayan glacial clays can be re- garded as a fixed horizon; but, when we come to consider how they l R. D. M. Verbeek, ‘ Topographische & Geologische Beschrijvying van een Gedeelte van Sumatra’s Westkust’ Batavia, 1883, pp. 29, 240-47, 247-67. 2 N. Wing Easton, ‘Hen Geologische Verkenning in de oba-Landen’ Jaarb. Mijnw. Nederl. O.-I. vol. xxiii (1894) Wetensch.-Gedeelte, pp. 126-28. 3 A. Rothpletz, ‘Die Perm-Trias & Jura-Formation auf Timor & Rotti im Indischen Archipel’ /bid. pp. 12-62. 4 G. Zeil, ‘Contribution a l’Etude géologique du Haut Tonkin’ Mém. Soc. Géol. France, ser. 4, vol. i, No. 3 (1907). ° H. Lantenois, ‘Note sur la Géologie de ’Indo-Chine’ Op. cit. No. 4. 6 *Contribution a la Carte géologique de l’Indo-Chine: Paléontologie,. 1908’ Imprimerie d’Extréme Orient, Hanoi-Haiphone. 7 TI am aware that Mr. S. H. Ball & Mr. M. K. Shaler have described a ‘Central African Glacier of Triassic Age’ Journ. Geol. Chicago, vol. xviil (1910) pp. 681-701, and have noted the very scanty evidence on which their determination of age is based. Bot MR. J. B. SCRIVENOR ON THE [June 1913, are to be described with regard to the European geological sequence, we find that the matter is not so simple as one might imagine. This can be illustrated by extracts from the ‘ Manual of the Geology of India’ 2nd ed. (1893). On p. 121 it is stated that fossils from the beds above the boulder-clay of the Salt Range show that they are approximately contemporaneous with the marine Carboniferous of New South Wales, and that these Australian beds were formerly regarded as equivalent to the Lower Carboniferous of the European sequence, but are now considered as Upper Carboniferous, if not homotaxial with the Permo-Carboniferous of Europe. On p. 125 we read of the uppermost division of the Lower Productus Beds :— ‘This fixes the homotaxis of these beds as Upper Carboniferous, or inter- mediate between that and Permian,’ On p. 127 we read of the Middle Productus Beds :— ‘These Mesozoic forms preclude us from assigning the group to an older ‘date than the Permian’ ; but the plate facing p. 126 has the legend ‘ Permo-Carboniferous (Middle Productus Limestone) fossils.’ } The Talchir Boulder-Bed (p. 208) is referred to the Upper Car- boniferous, and is regarded as belonging to the same horizon as the boulder-bed of the Salt Range; but on p. 207 we also read that ‘the suggestion made by Mr. H.F. rab avin d in 1875, that the Talehir Boulder- Bed was contemporaneous with the Permian glacial deposits of England, has never been absolutely disproved, and as recent investigations have shown that the supposed Lower Carboniferous deposits of Australia are newer than they were formerly considered to be, it is still possible that this may be the true equivalence.’ Then the base of the Productus Beds may be Permian also? The glaciation may, therefore, have occurred at any time from the Upper Carboniferous to the Permian. The extracts concerning the Productus Beds alone, given above, show that the glaciation may have been at least as late as the Permo-Carboniferous. In Sir Archibald Geikie’s ‘Textbook of Geology’ occurs the following passage, illustrating this doubt as to the date of the late Palaeozoic glaciation :— “The evidence now accumulated from South Africa, India, Cashmere, and ‘Australia, seems to point to some general operation on a gigantic scale in the southern hemisphere at the close of the Carboniferous or in the Permian Period. (4th ed. vol. 11, 1903, p. 1060.) This is interesting and important, in connexion with the Malayan glacial deposits and the underlying Raub Series. If the glacial ‘beds were assumed to be Upper Carboniferous, with no alter- native—then the paleontological evidence which points to the 1 Dr. E. W. Vredenburg, in his ‘Summary of the Geology of India’ (1907), gives on p. 42 the following classification of the Productus Beds :— Lower Productus and lower part of the Middle Productus Beds=Upper Carboniferous. Remainder of Productus Limestones=Lower Permian (Permo-Carboni- ferous or Artinskian), a Vol. 69.] GEOLOGICAL HISTORY OF THE MALAY PENINSULA. Jo Raub Series being either Carboniferous or Permian, or Permo- Carboniferous, would be a serious difficulty. If, however, one remembers that the glacial beds may be as late as Permian, then the dithiculty disappears; and the Raub Series can be regarded as older than the Productus Beds, unless it is in part equivalent to the shales underlying the boulder-beds in the trans-Indus. section of the Salt Range.’ This climatic horizon may, therefore, be referred to the similar horizons in India, South Africa, aud Australia; but, in general terms, we can only say that its age may be anything from the Upper Carboniferous to the Permian, more probably nearer the latter. The glacial clays are regarded as the base of the Malayan Gond- wana rocks, just as the Talchir glacial deposits are the base of the Indian Gondwana Series, and I must now justify my use of the term ‘ Malayan Gondwana rocks.’ The Myophorian Sandstone is marine, but the rocks with which it is associated and the absence of interbedded limestones show that it was deposited close to the shore. The fossils found in the extension of the rocks in Singapore are also marine,” but for Podozamites anda seed referred to Carpolithes. The occurrence of the former of these plants led Mr. Newton to suggest that these rocks are an outlier or extension of the Upper Gondwanas of India.’ In Perak a phyllopod has been collected. from shales associated with the typical conglomerate, described as Estheriella radiata, var. multilineata,* which may have been incor- porated in the rock under marine conditions, although the living Estherie are confined to fresh or rarely brackish water. Nicholson & Lydekker say° that fossil Hstherie not uncommonly occur in conjunction with undoubted marine remains, but that they appear, on the whole, to occur most frequently in those accumulations that “have been decidedly the result of brackish-water inundations and of more permanent lagoons (Jones).’ No other fossils of homotaxial value, other than those collected in Pahang, Perak, and Singapore, have been discovered as yet in these rocks; but the evidence afforded by those that have been collected, coupled with the climatic evidence of the Gopeng Beds, seems to me sufficient for the belief that we have here an extension of the Gondwana System of India. It is not claimed that the circumstances of the formation of the Malayan rocks were identical with those under which the mass of the Gondwana System was laid down. That is clearly impossible, seeing that, although there is. 1 ‘Manual of the Geology of India’ 2nd ea. (1893) p. 120. 2 See R. B. Newton, ‘ Notice of some Fossils from Singapore, &c.’ Geol. Mag. dec. 5, vol. iii (L906) pp. 487-96 & pl. xxv. 3 Op. cit. p. 488. 4 Tt. B. Newton, ‘Note on the Age & Locality of the Estheriel/a Shales from the Malay Peninsula’; also T. R. Jones, ‘ Note on a Triassic Esthericlla from the Malay Peninsula’ Geol. Mag. dec. 5, vol. ii (1905) pp. 49-52 & pl. il. 5 ‘Manual of Palzontology’ vol. i (1889) p. 511. 356 MR. J. B. SCRIVENOR ON THE [June 1913, some petrological similarity, the Malayan rocks have yielded many ‘distinctly marine forms; while the bulk of the Gondwana deposits of India have yielded land-forms only (plants, amphibia, and reptiles). The occurrence of Estheriella, however, is suggestive, as Estherie are found in the typical Gondwana rocks of India,’ sometimes with remains of plants, amphibia, reptiles, and fishes. Nevertheless, no ‘such remains have been found with the Perak Estheriella as yet; -and there is not sufficient reason to suppose that in any part of the Malayan Gondwanas the mode of deposition was identical with that of the bulk of the Indian Gondwana System. The Malayan rocks appear to have been deposited under much the same circum- ‘stances as the Ragavarum, Tripetty, Vemavarum, and Sripermatir Beds of the Gondwana System on the eastern coast of India, in which marine organisms occur together with plant-remains.* At the base of the Malayan Gondwana rocks is a climatic horizon that we can regard as fixed. Is there any other horizon in these rocks that can be regarded as fixed? ‘The presence of Estheriella ii Perak points to the Trias. Mr. Newton says of the beds containing the Singapore fossils that they ‘may be of Middle Jurassic age, and about the horizon of the Inferior Oolite of England. (Geol. Mag. dec. 5, vol. iii, 1906, p. 488.) The Myophorian Sandstone of Pahang Mr. Newton referred to the Rheetic, because of the presence of Chlamys valoniensis. Miss M. Healey, who has described the Napeng Beds of Upper Burma as Rheetic, supports Mr. Newton in his views as to the age of the Myophorian Sandstone.* There seems, then, to be a strong case for the existence of a definite Rheetic horizon in the Peninsula. Let us -see how this works in with the other evidence. Taking the Malayan glacial beds as equivalent to the Talchir Group of Orissa, then the Myophorian Sandstone would be the equivalent of the Mahadeva Group, or possibly the Panchet Group of the Indian Gondwanas.* ‘The Singapore fossils, however, were found almost directly on the line of strike of the Myophorian Sandstone, and it seems probable that we shall have to take full advantage of the doubt expressed by Mr. Newton as to the age of these Singapore rocks, in order to reconcile the facts. Apart from this, there is the further difficulty of fitting in the comparatively small outcrops of the Malayan Gond- wanas, as a whole, into their places in the great thickness of the Indian sequence. The Mahadeva Group is stated to be 10,000 feet thick, the Panchet Group 1800 feet. The Myophorian Sandstone * as exposed on the Benta-Kuantan road in Pahang is 10 feet thick. But the Malayan Gondwanas are littoral deposits; and, if we ~ imagine the Gondwana coast-line in these parts to have been slowly advancing eastwards, perhaps with many checks and oscillations, then the evidence becomes more intelligible. This hypothesis: 1 ‘Manual of the Geology of India’ 2nd ed. (1895) pp. 170, 171, 185. 2 Ibid. p. 180, &e. 3 «The Fauna of the Napeng Beds or the Rhetic Beds of Upper Burma’ Pal. Indica, n. s. vol. ii (1908) Mem. 4, p. 2 (Mem. Geol. Surv, India). + «Manual of the Geology of India’ 2nd ed. (1893) p. 208. Vol. 69.] GEOLOGICAL HISTORY OF THE MALAY PENINSULA. 307 namely, that of the Gondwana coast-line advancing from west to east, has been adopted, in order to explain the occurrence of the glacial rocks in Perak and the Rhetic horizon in Pahang. It will be interesting to see how far future work supports it. XI. Tue Growru or rHE Matay Purninstra, Starting from the late Paleozoic climatic horizon given by the glacial rocks, one can now form some idea of the history of this part of the globe. The time was that which saw the beginning of the Productus deposits of the Salt Range and the beginning of the Gondwana System in Peninsular India. Prior to the advent of glacial conditions, the site of the Malay Peninsula had been covered by a sea in which calcareous deposits (the Raub Series) were being laid down. ‘hese may have been in part time-equivalents of the beds which underlie the boulder-beds in the trans-Indus section of the Salt Range. But for this possibility they must be regarded as older than the Productus Beds. Submarine eruptions had occurred over part of the floor of this sea, and were continued into later times. The advent of glacial conditions coincided with the advance of the coast-line of Gondwanaland to the site of the Malay Peninsuia. The constitution of the glacial deposits gives some idea of the surface of this portion of Gondwanaland. It was partly formed of stanniferous granitic rocks (the Paleozoic Granite), tourmaline- granite being common, and of rocks metamorphosed by the Paleozoic eranite-magma. Some of the rocks forming this part of Gondwana- land evidently held quantities of corundum, both as pure massive corundum (now found as boulders), and as granular corundum in the tourmaline-corundum rocks of Kinta. The glacial deposits were succeeded by the littoral Malayan Gondwana rocks, deposited as the coast-line moved slowly eastwards until, at the least, Rheetic times were reached. Then the record is broken, until the intrusion of the Mesozoic Granite in late Mesozoic times ; and the intrusion of this granite was made possible by earth-movements which gave rise to the present main structural features of the Peninsula. Most of the literature dealing with the Peninsula mentions the great granitic axis, and it would not be surprising to find that this axis is regarded as the dominant structural feature. The key to the structure, however, is found, nct in any granitic range, but in the Main Range Foothills of Pahang, built up of Gondwana rocks. This range of foothills is composed of the eastern limb of one great anticline and the western limb of another. The one is the Main Range Anticline, the other the Benom Anticline, and they are the framework of the Peninsula: although it is evident that, on both sides of the country, less notable disturbances have admitted smaller granite-intrusions. The Main Range Anticline has been studied in detail in Perak and Pahang. It should strictly be described as a shattered anticlinorium, Temiang Bircham Tambun Tengah Ginting Datch on UN a Ampang a rp = ae Z, By & Z, ) ey — Kroh Marawan Hig. 1. Diagram to illustrate the formation of the limestone-hills in the Kinta Valley by faulting. - : Nasi Sehabat Sa I Vol. 69. | GEOLOGICAL HISTORY OF THE MALAY PENINSULA. 359 and in the Kinta district of Perak one observes striking evidence of the magnitude of the faulting that accompanied the earth-move- ments. ‘This is shown diagrammatically in fig. 1 (p. 358). The shaded areas represent those groups of limestone-hills, the cliffs of which are known by field-evidence to be for the most part fault- faces. On the east it will be noticed that three groups of hills abut on the granite; and in each group there is evidence that the line of the granite-junction is a line of fracture,' the downthrow side being occupied by the granite, into which the limestone and Gond- wana rocks sank bodily before the magma solidified, except for some quartzite and phyllites found at the summit of Gunong Riam (or Kerbau), which are the remains of the Gondwana rocks, or of rocks younger still, floating on the very highest part of the range.* The groups of limestone-hills are portions of the Raub Series which sank on to the magma relatively less than the rocks that form the floor of the Kinta river-valley, or which were raised relatively higher while the granite welled up. ‘The arrangement of the groups is interesting, as showing the trend of the lines of stress. The main line of fracture, on the east, takes a right-angled turn at the bottom of the diagram. From the corner of this angle the granite-border trends to the west of north, and a marked, but interrupted, line of fracture in the limestone-hills runs through Tempurong and Kandoh, and through the small hills north of Gopeng to Rapat, parallel to the granite-border. Near Gopeng the granite-border turns northwards, and the lines of the limestone- cliffs north of Puah and Pipit show other lines of weakness parallel to the main fracture; but in the Kroh-Marawan Group there is evidence of other fractures radiating from Puah and Pipit. The Lang Group, near Ipoh, is roughly parallel to the border of the granite of the Kledang Range on the west side of the valley. This range, as may be seen from the sketch-map (Pl. XX XV), is a spur coming off from the Main Range ; and it marks a small subsidiary fold in the crust, connected in the north with the Main Range Anticline. Subtending the angle at the bottom of the diagram are, as we might expect, other lines of weakness in the Sepah- Meusah-Kandoh Group and in the Gajah-Tempurong cliffs. The Kinta district affords very clear direct evidence of the lime- stone-hills being due to faulting on a large scale, and of the granitic margin of the Main Range being a line of fracture. In Pahang, where the limestone-hills are fewer, direct evidence is so far wanting as to both points; but it is safe to conclude that the con- ditions are the same. The Kinta district also affords evidence of magmatic stoping on a grand scale. The Benom Anticline, too, should be described strictly as an enticlinorium. The Main Range Foothills constitute the western limb of Gondwana rocks. In the centre of Ulu Pahang occurs 1 See ‘ The Gopeng Beds of Kinta’ Q. J. G. 8. vol. lxviii (1912) pp. 125-55, 2 One outiier of phyllites is known near Gopeng within the granite-area. There may, of course, be other such outliers. OndyGis. Nov 274. 23 360 MR. J. B. SCRIVENOR ON THE [June 1913, the older Raub Series, with outlying patches of Gondwana rocks and the Benom Granite; while the Main Gondwana Outcrop, less disturbed by folds and faults than the Gondwana rocks of the Main Range Foothills, forms the eastern limb of the anticline. This, then, is the foundation of the structure of the Peninsula: two great anticlinoria side by side, the formation of which admitted of the intrusion of the granite of the Main Range and of the Benom Range. It will be noted, moreover, on the sketch-map(P1. XXXV) that the prolongation of the Peninsula as far as Singapore is, in all probability, due to the resistant character of the Gondwana rocks n the eastern limb of the Benom anticlinorium. It is, perhaps, partly due also to minor intrusions of granite that have added to the power of resisting the agencies of weathering. XII. Srzcrat Points IN CONNEXION WITH THE Benom ANTICLINE. There are some special points worthy of note in connexion with the Benom Anticline. The first concerns the Tahan Range, which forms, in the north of Pahang, the western border of the Main Gondwana Outcrop. This range rises to over 7000 feet, and the altitude of the rest of the outcrop is insignificant compared with it. Gunong Tahan is the highest peak in the Peninsula, but ifs raison d’étre is unexplained. The extraordinary course of the Tembeling River shows that the mountain must long ago have constituted a formidable obstacle, turning the river sharply southwards ; but it is not clear why it should be so much more resistant to denudation than the rest of the Main Gondwana Outcrop. It may be that intru- sions of igneous rocks which do not appear on the surface are the cause: yet this hardly seems probable. A more likely explanation is that when the Peninsula, in late Tertiary times or later still, was an island or group of islands (a subject which will be discussed on a subsequent page) the sea advanced over the greater part of the Main Gondwana Outcrop, reducing it by denudation, but receded before it could attack the portion of the outerop which is now the Tahan Range. Another cireumstance is that there is a marked difference between the mineral products of the Benom Anticline and those of the Main Range Anticline. The chief products of the latter are tin- ore and wolfram. In the former, however, tin-ore is scarce; but gold in small quantities is widespread, while rutile and zircon are known to occur in some abundance. Those who have read books on the Malay Peninsula will have noticed references to a ‘ gold-belt’ stretching from Negri Sembilan through Pahang and into Kelantan. Until I had worked in Ulu Pahang for some time, the existence of this belt, in which gold is undoubtedly more abundant than elsewhere in the Peninsula, puzzled me. It is now clear, however, that the area covered by the Benom Anticline is the gold-belt; and, if one remembers that the Benom granite-mass is mostly hornblende-granite, with which syenites are associated, also that in this area the dacites, andesites, Vol. 69.] GEOLOGICAL HISTORY OF THE MALAY PENINSULA. 361 and dolerites of the Pahang Volcanic Series have their greatest development, it is unnecessary to quote scientific literature to show that the difference in mineral products is consequent on the -difference between the nature of the igneous rocks in the Benom Anticline and those in the Main Range Anticline. Last of the Benom Anticline are stanniferous granites similar to the Main- Range granite. This difference between the rocks of the Benom Range and the tin-bearing granite-ranges leads on to another interesting subject, which it is impossible to discuss fully here—although it may be mentioned briefly. When describing the rocks of Pulau Ubin and Pulau Nanas,’ I remarked on the early differentiation of a granitoid and a gabbroid magma under the site of the Peninsula and the neighbouring Archipelago. Now, in the Benom Range pyroxene- biotite-syenite has been found; and to the south, in the Rumpin district, a fine-grained norite has been collected, the relation of which, however, to the Benom Granite is obscure. The presence of norite suggests another intrusion from the same or from another gabbroid magma, and the presence of the pyroxene-bearing rocks in the Benom Range suggests a probability of their connexion with a gabbroid magma also. The difference between the felspars in the Benom pyroxene-bearing rocks and those in the Pulau Nanas pyroxene-bearing rocks is against their direct origin from the same magma; but it will be allowed that such rocks might be derived ultimately from the same gabbroid magma, if we con- sider the possibilities of a preliminary magmatic differentiation and the chances of admixture of the granitic magma. The less acid character of the Benom rocks, as a whole, compared with the rocks -of the Main Range, may be due to such a mixture of magmas. It might, however, be argued that the abundance of hornblende- granite in the Benom Range is due to the melting of masses of calcareous Raub-Series rocks in the magma before it solidified. I do not incline so much to this view, however, because in the Main Range it is clear that enormous masses of calcareous rocks must have been stoped away—yet hornblende-granites are not, by any means, so strongly developed as in the Benom Range. It is quite likely, nevertheless, that: the masses of calcareous rock stoped away ‘in both ranges gave rise to some hornblende. It is interesting to recall Prof. F. Loewinson-Lessing’s views on the origin of igneous rocks in this connexion.” He regards a granitic and a gabbroid magma as the two principal magmas from which all igneous rocks have been derived, and favours the view that all syenites are only local facies of a granitic or gabbroid magma. This is certainly the case with a syenite near Taiping, in Perak, the rock being a local modification of granite; but, in the -ease of the pyroxene-syenites of the Benom Range, a mixture of two magmas seems to be the more probable cause of their formation. 1 Q.J.G.S. vol. lxvi (1910) pp. 482-33. 2 «The Origin of the ‘Igneous Rocks’ Geol. Mag. dee. 5, vol. viii (1911) ‘p. 254. 2B 2 362 MR. J. B. SCRIVENOR ON THE [June 1913, XIII. Tertiary anp Recent Caancus In THE PENINSULA. From the evidence in the Archipelago of the existence of Eocene rocks, some containing granite-pebbles, we must conclude that, after the granite had solidified, rapid denudation of superincumbent deposits (which have now disappeared entirely) brought the granite and the rocks of the two anticlinoria to light. The only record of Tertiary deposits known so far in the Peninsula is- afforded by the Coal Measures in Selangor ; these may be Miocene, and of them I need say no more now. . Biological evidence, as shown by Dr. A. R. Wallace in ‘ Island Life’ 1880 (p. 362), points to the Peninsula and Archipelago having formed one mass of land during some part of the Tertiary Era, and the shallowness of the sea which surrounds the islands of the Archipelago, and borders the Peninsula and Siam, shows that no very great elevation would be required to restore these conditions as far as the Straits of Macassar, between Borneo and Celebes. In the Peninsula itself, however, there is evidence that a period of elevation is now actually in progress. This evidence is the existence of old sea-beaches inland. One well-preserved beach can be seen at the foot of Gunong Geriang, near Alor Star; another in the flat country between Telok Anson and the sea. But more than this, there is evidence showing that the Peninsula, not so very long ago, was itself an island, or group of islands, formed of what are now the mountain-ranges. The low country to the west of the Kedah- Singgora Range, without any important stream, can only be regarded as a plain of marine denudation. The Kedah River comes down from the hills that once formed part of the island or island-group. Better evidence than this is that adduced by Mr. H. N. Ridley, who shows that the difference between the pre- sent floras of Lower Siam and the Peninsula south of Kedah Peak is sufficient to suggest that the latter was separated by sea from the land on the north.* This combined geological and botanical evidence adds an interesting chapter to the history of this part of the world, of which we have not yet seen the end. After the destruction by sub- mergence of the land-connexions that aliowed the faunas of Borneo, Java, and Sumatra to migrate from the north, the subsidence con- tinued until the Peninsula became an island. Subsidence then gave place to elevation, the Peninsula came into being again, and there is in progress a gradual approach to the old conditions of an united Peninsula and Archipelago.” 1H. N. Ridley, ‘An Account of a Botanical Expedition to Lower Siam’ Journ. Straits Branch Asiat. Soc. No. 59 (Aug. 1911) pp. 29, 30. 2 In the paper on ‘The Geology & Mining Industries of Ulu Pahang’ I have endeavoured to put forward an explanation for the course of the Pahang River. As may be seen from the sketch-map accompanying that paper, the Pahang River suddenly turns at right angles, and flows through the Main Gondwana Outcrop. The suggested explanation is that the Pahang River once flowed on southwards, and emptied itself into the Straits of Malacca near the mouth of the present Muar River, in Johore, but was captured by a small river that cut back through the Main Gondwana Outerop (op. cit. pp. 7-9). [-unSoeq oraM suoruiedo Surturar atojaq sXepo vivMpuoy of} JO WOLvUTpUT aTquqoad dl} SozWOIPUL OUI] UAYOAG peatno oT, “SpAvaAtIAop pau Asta Uv 4L SAIPU cgBM-2ovJins “owojsawl] ayy ur, dno, a3 Jo WorNUIAO} aq} JO asNVd 9T]} Ajqeqoad sea gyney sty} jo ootasaad oy} : ounpd-ypnez Pesto Aat otf} UT saproutod sult qsvouodo at} JO [TUM UW.19jJ8OM OILY, “AUly Udyotq vB Aq peyvolpul ST voRyINS [BUISiA0 OT, + Jo] ULS|PStoy Sado OUI] TBOIAEA OT, “oTLOS OF WALI UOT}oas B WLOTZ paonpad st oroqe any | b] 363 te — TSR RS RIC I A A SR SPE SE EES RI SEIT al clays in Kinta ‘aqiueuy jO suo!lsnuqui uqiM sydoy eueMpuog uagunoa ee ee ee Ne eee ae a LL XIV. Tues Formation or Licgnire in Livesronn-‘ Coes.’ —_— 2 eoejune JeulsiI9 = tion of lignite and sand with the formation of ‘ cups in asem | GEOLOGICAL HISTORY OF THE MALAY PENINSULA. 1a is The asso by solution in the limestone under the glaci Vol. 69. ] . 6 e . SPMMJSAMN-Y}.L0U-Y9.L0W buryoo) aur asnouacdo YOuony, 2Y7 fo WOnvIg—'*G “OT =e demands attention, not only because it constitutes an interesting type of recent deposit, but also because it proves o be a good example of the growth of coal in situ. n examination to The formation of 364 MR, J. B, SURIVENOR ON THE [June 1913,. the limestone-‘cups’ is simple. The limestone is traversed by abundant fault-, joint-, and bedding-planes, which give facilities for attack by water percolating down slowly from above or by springs rising from below. Part of one divisional plane may afford an easier means of attack than another, with the result that there the limestone is dissolved away more quickly. This soon shows itself in the formation of a ‘cup’ or trough on the surface of the limestone, into which the glacial clays must sink, forming a lining to the cavity. The centre of the cavity becomes filled with whatever lies above the glacial clays. The distances from the top. of the pinnacles of the limestone-surface to the bottom of the ‘ cups’ has not been measured systematically, but the average is probably about 35 feet. The deepest and most interesting of all the ‘ cups’ known to-day is that in which the famous tin-deposits of the Tronoh Tin-Mining Company lie. Fig. 2 (p. 363) gives some idea of this ‘cup,’ and it will be noted that one side of it is bounded by a reversed fault, whereby the limestone and glacial clays have been pushed up against the younger Gondwana rocks. The infilling of the ‘ cups’ is generally ignite, mixed with a certain amount of sand, which in some cases forms distinct beds. It is only necessary to consider the course of events, if a stream were to: flow over the site of one of these ‘cups’ when it first began to be formed, to understand the significance of the deposit of lignite. The solution of the limestone under the clay would result in a subsidence of the surface over which the stream was flowing. This would lead to the formation of very marshy ground, where the dead vegetation of the tropical forest would fall and accumulate, mixed with alluvial sand brought down into the swamp from higher ground. So long as the limestone continued to dissolve, the subsidence and accumulation of dead vegetation and alluvial sand must have continued also—sinking ever farther down into the ‘cup,’ and affording an example of the growth of coal-deposits in situ. XV. Torgentrat Depostts. When the idea that the clays of the Kinta Valley are glacial deposits first presented itself, particular care was taken to avoid the mistake of ascribing to glacial action boulder-deposits that might have been formed under torrential conditions. The fact that there are in the Peninsula recent torrential deposits, although of a peculiar type, was of great assistance. A brief account of them will be of interest. A feature of the granitic outcrops is, that to a depth of 20 or even 30 feet, they are weathered to a soft sandy clay that can be cut by hand, but in which veins and faults may still be clearly distinguished. In this granitic clay are numerous cores of hard granite that have resisted weathering. They are of rounded out- line, and when divested of their clayey envelope are generally mis- taken for waterworn boulders. In order to distinguish them from waterworn boulders, I have always referred to them as ‘core- Vol. 69. ] GEOLOGICAL HISTORY OF THE MALAY PENINSULA. (365 boulders.’ When the decomposed granite is attacked by the mountain-torrents, it is evident that the clay and sand will be washed away, and that the core-boulders will accumulate as huge masses of rock, packed close together and lying on unweathered or partly-weathered granite, in the beds of the streams. The core-boulders themselves act as checks for sand coming down with the stream from above, and the interstices between the lower core-boulders are partly or wholly filled with sand. Sometimes one finds in the jungle a large deposit of core-boulders, and can hear the stream rushing through them far below and out of sight. Chinamen burrow among them to get the tin-ore coneentrated behind them by nature, and not uncommonly are killed in the process by upsetting the equilibrium of some tons of hard granite. A demonstration of how such accumulations of core-boulders can be formed by torrents was afforded in December 1911 in Ulu Pahang, when a terrific downpour of rain struck the slopes of the granite-mountains on which the Trunk Road from Selangor descends to a little township called Tras. The effect of this down- pour had to be seen to be believed. Acres of jungle-soil, trees, and core-boulders went crashing down the hillsides under the extra weight of water, the Trunk Road in many places disappearing with them. The small streams became roaring torrents, hurling boulders and trees into the main stream far below, and on to portions of the road that had escaped total destruction. Part of Tras, at the foot of the range, was overwhelmed by the masses of coarse sand poured down the mountain-side. There is a difference between these torrential accumulations of core-boulders and the glacial clays of Kinta that is readily dis- tinguished. The former have been formed by the sorting action of water: the case of Tras shows this clearly. The boulders were left heaped up in the hills, boulder touching boulder or resting on hard rock. ‘lhe sand was swept down to Tras, and dumped there on the flat land. ‘The clay went farther still. Ultimately, we may expect, the interstices between the boulders will be filled up, in part at any rate, with sand brought down by the streams when they are low; but no one who had seen such deposits would be able to conclude that the boulders had been deposited in the sand, or at the same time as the sand. In the glacial clays, on the other hand, there is striking evidence of the absence of the sorting action of water, which alone makes it impossible to regard them as torrential deposits; and with the exception of one case, at Redhills (in Kinta), the boulders are not heaped up together or touching one another. XVI. Conctuston. The object of this paper being to give some idea of the geological history of the Peninsula, I cannot discuss at any length the con- nexion of rocks in the Peninsula with rocks in the Archipelago, Cochin China, the Shan States, and Burma. That there is a close 366 MR. J. B. SCRIVENOR ON TILE [June 1913. connexion between the rocks in these regions may be regarded as probable on structural grounds; but, im the case of all the countries mentioned, nothing is needed so much as detailed paleontological research, which cannot be undertaken by geologists who are engaged in economic work. The Dutch geologists are very little or no better off in this respect than myself, if the comparatively greater extent of the area with which they have to deal is considered. The small collections of fossils obtained do but serve to give a rough notion of the geological horizons. There are two points, however, that 1 would mention. One is the relation of the Raub Series to beds some distance away to the north. Dr. J. M. Maclaren, in his work on ‘Gold; its Geological Occurrence & Geographical Distribution’ 1908 (p. 287), seems to be of the opinion that the Raub Series will, on examination. prove to resemble closely certain limestones and shaly beds in the Southern Shan States, described by Mr. C. 8. Middlemiss,* which have been referred to the horizon of the Middle Productus Beds. f have not seen the limestones of the Southern Shan States, and Dr. Maclaren, I believe, has not seen those of the Raub Series ; but it may be that the prediction will prove correct, even if the close resemblance is to include contemporaneity. The only way to proveit, without very good paleeontological evidence, is to survey the long stretch of country between the Southern Shan States and the Peninsula. In the Northern Shan States the Napeng Beds are found lying - unconformably on limestone, or separated from it by faults.” This is suggestive of the relations between the Malayan Gondwana rocks and the Raub Series, and it would not be surprising to find that the Napeng Beds have the same relation to the Gondwana rocks of India as the Malayan rocks. The beds overlying the limestone in the Southern Shan States, again, are described as being ‘let down by faulting’ or ‘tucked in along certain lines and axes of reversed folds and faults,’® but there does not seem to be a close resemblance petrologically to the Malayan Gondwana rocks. The limestones in Indo-China also, referred to the Permo- Carboniferous, may ultimately prove to be part of the same forma- tion as the Raub Series (see p. 353). At present, the most important point to remember in this connexion is that, taking the glacial horizon in Perak as being equivalent to the Talchir and other contemporaneous late Palzeozoic glacial deposits, the attempts to correlate the Raub Series with the Productus Beds of the Salt Range on the scanty paleontological evidence * must be abandoned, unless we assume the series to be contemporaneous with the shales underneath the boulder-bed in 1 * Report on a Geological Reconnaissance in Parts of the Southern Shan Slates & Karenni’ Gen. Rep. for 1899-1900, pp. 130 et segg. (Geol. Surv. India, 1900). * M. Healey, ‘ Fauna of the Napeng Beds, &c.’ Pal. Indica, n. s. vol. ii (1908) Mem. 4, p. 1 (Mem. Geol. Sury. India). 3 CO. 8. Middlemiss, op. supra cit. p. 143. 4 See, for example, Geol. Mag. dee. 5, vol. iv (1907) pp. 565, 566. Vol. 69.] GEOLOGICAL HISTORY OF THE MALAY PENINSULA. 367 the trans-Indus section of the Range.’ If ultimately it should be proved that the limestones of the Southern Shan States are the same as those of the Raub Series, then it would follow that those also are older than the Productus Beds of the Salt Range, with the same reservation regarding the trans-Indus section. The other point is the continuation of the rocks of the Peninsula beyond Singapore. I have already quoted Prof. Suess * as follows :-— ‘Still further south this long granite range [the Main Range] breaks up into isolated ridges, and, associated withancient sediments, reaches the sea near Singapore. A series of cliffs and smaller islands reveals its continuity with the tin-producing islands of Banka and Billiton.’ Unless we interpret ‘near Singapore’ as meaning Negri Sembilan and Malacca, which to my mind is impossible, we cannot accept this statement as giving the facts of the case. The Main Range tails off in Negri Sembilan; Mount Ophir may he the end of the Benom granite-intrusion ;.and there is very good reason for sup- posing that the Main Gondwana Outcrop is continued into the island of Singapore. A glance at an atlas will show that we mav expect the rocks of this Gondwana outcrop to be represented in Banka and Billiton. More I cannot say, as I have not visited these islands, but Dr. Verbeek’s description does not show anything that makes the continuation improbable, except perhaps one item regarding the relations of radiolarian chert and sandstones.” ‘he fact of the granite in these islands being stanniferous is no diffi- culty. his characteristic does not imply that the granite must be a continuation of the Main Range of the Peninsula; but only that it is probably of the same age as that granite and the granite of other ranges in the Peninsula, including ranges east of the Main Gondwana Outcrop. Prof. Suess shows in a map * trend-lines continuing from Billiton to Karimoen Djawa, off Java. Dr. Verbeek, in his map of Banka and Billiton,’ shows the lines of strike running through Banka in a south-easterly direction, then across nearly due east to Billiton. In Billiton they run almost due east at first, then fall away to the east-south-east, with which striké they leave the island. In Nangka and another island the strata show a strike almost due south- east, but these trend-lines are shown as turning up again to the east. This is interesting, as indicating that, while the rocks of Karimoen Djawa may mark a reappearance of the Banka and Billiton rocks, some of the Billiton rocks, which may be a con- tinuation of the Main Gondwana Outcrop of the Peninsula, bend round as though to enter Western Borneo: the curve being an inside are roughly parallel to the outer volcanic arc that runs down the 1 “Manual of the Geology of India,’ p. 120. 2 Particulars of the Atherfield Specimen, No. 2. The bones of this specimen are in one block, also obtained from the sea, which has likewise worn away the ends of many of them. That it does not belong to the blocks in specimen No. 1 is proved by its containing similar bones. They lie on a layer of hard blue limestone, but are embedded in the same matrix of silt. The following bones are preserved :— Scapula: The humeral end of the right scapula. Coracoid: The perfect right coracoid. Humerus: The distal halves of both humeri. The dorsal surface of the left and the ventral of the right are exposed. Radius and ulna: The proximal ends of the left radius and ulna. Metacarpals: The distat extremity of the right and the distal third of the left, wing-metacarpals. Phalanges: The proximal half of the right and left first wing-phalanges. Il. Descrierion of tHE SKELETON The skuil is nearest in outline to Pterodactylus ; but the occiput is square, and not rounded as in the figures and restorations of that genus. The extremity of the snout bane the brain-case are the only portions of the skull that are completely enveloped in bone. These two regions are connected dorsally by a triangular bar, and ventrally by thin band-like maxille. The tip of the muzzle is truncated. Here both upper and lower jaws are moderately convex from side to side, and gently curved longitudinally. There is neither nerve-pore nor foramen visible on the upper and lower Jaws. The upper jaw, 33 mm. from the tip of the muzzle, or above the seventh tooth, becomes laterally compressed—a compression which gradually intensifies, until at the commencement of the nares, the sides are decidedly concave. The dorsal outline of the beak makes a very acute angle with the lower jaw, which is ‘Vol. 69. | SKELETON OF ORNITHODESMUS LATIDENS, 379 ‘straight. There is no supra-occipital crest. The parietal region is but slightly convex from side to side, and, compared with the length of the skull, extremely constricted. There is no longitudinal arching of the cranial platform or the occiput (Pl. XXXVII, fig. 3). The crown and lateral borders of the back of the skull are semicircular, and the base concave (Pl. XXXVIII, fig. 1). The lower outer border is produced posterior to the condyle. ‘The intermediate area is deeply concave. The brain-capsule is very small. I estimate the length of the skull to have been 560 mm., and that of the mandibles 423 mm., which I obtain in the following manner. From the angles at which the proximal and distal ends ‘of the humerus, radius, and ulna were lying on the blocks, the missing section must have been about 89 mm. long. In the measurements of the skull and limb-bones I have taken this to be the length of the lost section. This would give the humerus the same length as the British Museum specimen, which is 220 mm. long; and, as the preserved portions of that bone in the Atherfield fossil are of the same size, it is no more than what would be -expected. The Vacuities of the Skull. The External Nares. The external nares (Pl. XX XVII, fig. 1, n.v.) begin not far from the extremity of the snout. They gradually expand backwards 140 mm. Here should occur the missing section, and all further trace of their shape and area would be lost, were it not for a moiety of bone (Pl. XXXVII, fig. 4, max.n.b.) 50 mm. long and 18 mm. ‘deep, attached to the inner face of the maxilla, 236 mm. from the -end of the muzzle. ‘his bone shows a thickening at its upper interior edge. The lowest portion of the anterior border exhibits a curved smooth outline, the extreme lower anterior boundary of the -antorbital vacuity, for I take this fragment of bone to be the lower end of a maxillo-nasal process. It has on its upper extremity a jagged fracture, thus proving a continuation of the bone in that direction. Perhaps additional proof is added by the beak breaking across, just posteriorly to this process, the weakest place in its length. Again, if the narial opening was confluent with the antorbital vacuity, the great cavity from the anterior border of the nares to the anterior margin of the orbit, taken in conjunction with the weak premaxillar bar and attenuated maxille, would appear to have been unable, without a strut, to prevent crumpling -on a strain of the jaws in prehension, for the weight of the skull is distributed at both extremities. I believe that the rest of the maxillo-nasal bar has been destroyed, and that the nasal was not confluent with the antorbital vacuity. Granting this, the nasal opening is ppraious, subtriangular in shape, slightly cone in position, and posterior to the teeth, Q. J. G. 8S. No. 274. 26 376 . MR. R. W. HOOLEY ON THE [June 1973,. The Antorbital Vacuity. The antorbital vacuity (Pl. XX XVII, fig. 2, a.0.v.) is large, elongately rhomboid, entirely separated from the orbit and the- nasal opening. Antorbital Vacuity No. 2. An additional preorbital vacuity (Pl. XX XVII, fig. 2, a.0.v. 2). is situated in front, beneath, and confluent with the orbit. It is shuttle-shaped, obliquely placed, and bounded by the jugal above and the quadratojugal beneath. In a profile view of the skull its. width appears much less than it is in reality. The Orbit. The orbit (Pl. XXXVIT, fig. 2, O.) is small, circular, and placed: very far behind the mandibular articulation. Except the narrow opening into the antorbital vacuity No. 2, it is entirely surrounded by bone. The anterior margin is formed by the extreme proximal end of the jugal and a moiety of the lachrymal, the roof by the- prefrontal and the frontal, and the posterior border by the post- frontal and postorbital: that is, if we take this buttress to ‘include: both these elements, as in Sphenodon.’* Its lower boundary is formed entirely by the quadratojugal, which here is hollowed as. far as the anterior region of the orbit, where a broadening of the. bone determines the extent of, but does not complete, the orbital. rim. There was no trace of a sclerotic ring. The Supra-Temporal Fossa. The supra-temporal fossa (Pl. XXXVII, fig. 3, s.t.f.) is deep, large, and thrown open laterally, because of the supra-temporal’ arcade rising obliquely forward from the lowest point of the outer edge of the back of the skull. It is bounded on its posterior and lower borders by the squamosal and a process from that bone, and: anteriorly by the post-fronto-orbital buttress. The Infra-Temporal Fossa. The infra-temporal fossa (Pl. XXXVII, figs. 2 & 3, 7.t,f.) is. large, directed obliquely, and extends in front of and behind the orbit for equal distances. It is bordered above by the squamosal: bar and the quadratojugal, and below entirely by the quadrate. The inner hinder border of these bones forms a rising floor under the posterior end of the vacuity, which prevents its full extent from being observed in a profile view. 1 EK. T. Newton, Phil. Trans. Roy. Soc. 1887, ser. B, vol. clxxix (1888), p. 906. Vol. 69. | SKELETON OF ORNITHODESMUS LATIDENS. 377 The Bones of the Skull. The Premaxille. The premaxille (Pl. XX XVII, fig. 5, p.) comprise the whole of the upper jaw anterior to the nares, and include the whole alveolar tract of each side. Dorsally they are produced backwards as a triangular rod, which is nowhere wider than 15 mm. This bar is prolonged to the frontal, but to what distance they continue to take a share in it is not clear. The premaxillo-maxillar suture is apparently beneath the anterior edge of the nares. The Maxilla. The maxilla (Pl. XX XVII, figs. 2, 4, & 5, m.v.) is an extremely thin, long, narrow bar of bone, of little depth. There is a slight increase in depth at each end, with the posterior extremity the more expanded. Here the inner dorsal margin is raised above the outer, and on its posterior border it is fused to the jugal. Its exterior surface is concave. Near the tip of the snout, and below the anterior end of the external nares, the inner ventral margin is produced inwards, as a sheet of bone, and meets a similar process of the maxilla of the opposite side, completely roofing the palate. How far backwards this plate was continued, it is impossible to say, on account of the lost section. The maxilla comprises the inferior boundary of the nasal and antorbital vacuity, and extends to the quadrate, without the intervention of the jugal. The maxilla is edentulous. The Nasal. The nasal apparently sends down a process to join that of the maxilla, nearly midway between the anterior end of the nasal and the posterior extremity of the antorbital fossa. That this is so seems to be proved by the presence of the maxillar process: for, where the nasal and preorbital opening is confluent, as in Ptero- dactylus, such a process is not found. The nasals are fused with the backward extension of the premaxille into a single median ossification. What extent of this dorsal bar they occupy is indeterminable. The Lachrymal. The lachrymal (Pl. XX XVII, fig. 5, 7.) is situated in the upper anterior corner of the orbit. It looks forward into the ant- orbital vacuity. It is triangular, with the apex of the triangle pointed downwards, and bifurcated: the two branches unite with the upper end of the jugal, and form together an elongated foramen. Where it shares in the orbital rim, it is strongly convex, and, between here and the prefrontal, concave. 2:62 378 MR. R, W, HOOLEY ON THE [June 1913, The Frontal. In the Atherfield specimen No. 1, only the extreme anterior end of the frontal is seen. It commences over the anterior third of the orbits, and here on the right side is a curious mammillated knob of bone (Pl. XXXVII, figs. 2 & 5, b.) over the upper border of the orbital rim, which most probably was paired on the left. Interiorly to this boss, the surface is concave, rising into a feeble convexity on the summit of the cranium. ‘The frontal unites with the lachrymals, prefrontals, and the premaxillar prolongation with a V-shaped suture, the angle being towards the oeciput. It lies below the prefrontals and the premaxillar extension, but not beneath the lachrymals along the line of suture. In the hinder portion of the skull in the B.M. R/176 specimen, the extent of the frontal and the other bones of the cranial roof cannot be seen. The cranial platform is a quadrilateral space. The Post-Frontal. The post-frontal is situated in the corner between the orbit and the supra-temporal fossa. It sends down a process which, in conjunction with the post-orbital (if that bone be present), comprises the posterior boundary of the orbit. The Parietal. The parietal arches the skull between the supra-temporal fosse. It is extremely constricted, so that it becomes very concaye on its lateral borders. At its junction with the occipital area the bone is raised. The Squamosal. The squamosal is situated at the posterior lower angle of the supra-temporal fossa. It sends forward and upwards a process to unite with the post-fronto-orbital bar, in forming the supra- temporal arcade. Below, it is fused to, and rests upon, the hinder end of the quadrate: this forms a strong buttress, upon which the brain-case is supported. The Bones of the Occiput. The right side of the back of the skull in B.M. R/176 is destroyed, and the left below the foramen magnum is covered by matrix. Nor are any sutures or striz visible on the upper half, so that the extent of the bones is indecipherable. Except a vertical ridge from the parietal border to the foramen magnum, the whole region between the outer borders is concave. The parietal, squamosals, and paroccipitals have expanded and coalesced into one concave plate, with the post-temporal fossz almost obliterated. The occipital condyle is large, and, as usual, set at right angles to the skull. Vol. 69.] SKELETON OF ORNITHODESMUS LATIDENS. 379 The Vacuities of the Occiput. The post-temporal fossa of the left side is well exhibited. It is quite small, subcircular, and placed far above the foramen magnum near the upper border of the occiput. The foramen magnum is very large. The Quadrate. The quadrate (Pl. XX XVII, figs. 2,3, & 5, Q.) is extremely long. It articulates with the mandibles as much as 99 mm. in front of the orbit. Its proximal end is remarkably robust, and so the overlying cranium is weak and fragile in coraparison. It forms a third of the depth of this part of the skull. Its proximal dorsal half bends inwards under the supra-temporal arcade. - Proximally; externally, it is fused with the squamosal process, between which and the paroccipital process it is immovably wedged. It les under the squamosal, and forms the lowest angle of the posterior end of the skull. In the median region it is much weaker, and mode- rately thick ; its dorsal half loses the inward curve, and the whole lateral surface looks outwards. ‘This continues to the distal end, where the bone again becomes more powerful, with a stout, convex, ventral border. Dorsally here it is anchylosed to the quadratojugal for 51 mm.; proximally to this it comprises the lower boundary of the infra-temporal fossa. From the interior surface at its distal end a strong bar of bone extends 29 mm. upwards and backwards. The angle thus made with the shaft of the quadrate is occupied by a wing of thin bone, which has its origin 86 mm. from the articular end. The pterygoid probably united with the inner angle of this wing, as in Scaphognathus purdom. The type of Sc. crassirostris is the only specimen that clearly denotes the form of the inner side of the quadrate. It exhibits a corresponding wing, although the distal border is not a straight line, but sigmoid, and the wing is apparently developed to the full extent of the bone. The articula- tion is a plain pulley-joint, above which the quadrate unites with the lower angle of the posterior extremity of the maxilla. The Quadratojugal. The quadratojugal (Pl. XX XVII, figs. 2, 3, & 5, Qu.) is a thin moderately-broad bone, rising obliquely from the maxilla to the anterior termination of the squamosal bar, near the hinder border of the orbit. It is anchylosed to the inner side of this bar. For about a fourth of its length it forms the lower boundary of the orbit, and for the remaining three-fourths that of the intra-orbital vacuity. At its lower end it is fused for 51 mm. with the quadrate and at its extremity with the maxilla. 380 MR. R. W. LOOLEY ON THE [June 1913, The Jugal. The jugal (Pl. XX XVII, figs. 2 & 5, J.) is a rod-like hollow bone, except at its lower end, where the inner and outer lateral surfaces are flat. It rises obliquely, yet feebly arched, to the lachrymal. Here it is bifurcated into short branches, the outer being club-shaped and passing backwards and downwards, forming a moiety of the anterior margin of the orbit. ‘The inner is rod-like, and connects with the interior border of the lachrymal. The distal termination is V-shaped, one branch joining a raised portion of the inner border of the maxilla and the other being fused with the interior surface of the quadratojugal at its dorsal edge. Its total connexion with the maxilla and the quadratojugal is only 5 mm. long. The Temporal Arcades. The jugal, quadratojugal, and quadrate all rise obliquely from the maxilla at nearly the same angle and free one from the other. The jugal takes no share whatever in the upper temporal arcade : this is formed by the quadratojugal and the squamosal bar. The squamosal bar overhangs externally the hinder end of both the quadratojugal and the quadrate. The lower temporal arcade is made entirely by the quadrate. The Palate. I have not thought it advisable, owing to its hardness, to clear away the matrix which lies in the angle made by the convergence of the mandibies, for fear of fracturing this end of the beak. On the area of the palate exposed, there is no trace of the internal nasal openings, and it is too near the anterior margin of the external nares for them to be situated in front. The Mandible. The mandible (Pl. XXXVII, figs. 1, 2, 4, & 5, mn.) is long, and the symphysis short. The alveolar tracts terminate close behind the symphysis. The rami of the mandibles gradually decrease in depth backwards ; but their strength is maintained by a correspond- ing increase of the width, and at the articulations they are bulbous. Near the symphysis they are convex ventrally; posteriorly they lose this, and become for some distance flat, with a convex upper and lower border. Behind the premaxille, they lie exterior to the upper jaw. On their inner dorsal margin there is a depressed ledge, on which the maxille rest, when the Jaws areshut. Beneath this shelf, the bone is concave. They terminate far in advance of the orbits. The extent of their different elements cannot be determined. Vol. 69. | SKELETON OF ORNITHODESMUS LATIDENS. 381 ? The Teeth. There are twenty-four teeth in the upper, and twenty-five in ithe lower jaw. Only twenty-three of the former are exposed, owing to a slight displacement of the upper jaw; through this ‘derangement the teeth of the right dentary are covered by the amatrix underlying the teeth of the right premaxilla, in such a manner that it is impossible to remove it, without endangering the overlying teeth. ‘The hindmost tooth on each side of the lower _jaw is posterior to all the teeth of the upper. All the teeth inter- lock. ‘They are compressed laterally and lanceolate, the smallest teeth being at the tip of the muzzle; these are followed gradually by longer and broader teeth. The two posterior teeth on each side of both jaws are broader, larger, and more bluntly pointed than the rest. A very marked characteristic is that the last two teeth of the mandibles fit into semicircular slots in the upper jaw (Pl. XXXVII, figs. 1 & 5); and the ultimate one of the upper jaw lies exterior to the lower jaw, the lateral outer surface of which is slightly concave to receive it but not slotted. These teeth, in life, must have been visible when the muzzle was closed. ‘They are a little longer than the others. The indentations in the upper jaw give an appearance to the last tooth of being set on the summit of a strong process. ‘The teeth are smooth and free from striz; but, on careful examination, there is to be discovered, on the outer surfaces of some of them, an incipient median carina. The alveolar borders of the upper jaw, anterior to the slots, are gently convex to the tip of the snout. Those of the lower jaw, immediately in front of the last two teeth, fall abruptly some distance below the plane of the tract occupied by those teeth, and from there they are feebly concave. ‘The posterior tooth of the left dentary is displaced, but attached by matrix to the surface of the bone near the dorsal border of the beak. This tooth is diamond- shaped, both crown and base forming equilateral triangles. All the teeth are vertical, and planted in separate sockets. The Vertebral Column. The hinder half of a cervical vertebra in the Atherfield fossil is ‘quite similar to an example in the B.M. specimen R/176. That example is much crushed, and has been fractured and cemented together, so twisted that the dorsal surface of the one portion is followed by the ventral of the other. This is apparently the example figured by Seeley’: itis proceelous. ‘The neural arch and “spime are missing. In the Atherfield example the neural spine is fairly high and robust, and the neural arches are flat and set at an oblique angle to the spines: they overhang the centrum. The neural canal is large. The centrum is long and narrow, becoming ‘moderately constricted in the central region. Laterally, a deep and 1 ¢ Dragons of the Air’ 1901, fig. 66 & p. 172. 3&2 MR. BR. W. HOOLEY ON THE [June 1913,- open valley traverses its length. Pneumatic foramina occur on each side. The ventral surface of the centrum is fiat without any earination, slightly concave at both ends, and at the posterior- extremity bifurcated into the usual tuberous processes with the- articular convexity between, but dorsal to them. ‘he pre-post- zygapophyses. arise laterally near the posterior third of the centrum, and are directed backwards, terminating some distance- from the posterior articulation of the centrum. A restored ventral view of this cervical is given in Pl. XXXVIILI, fig. 2. The last two cervical vertebree have their zygapophyses laterally, and centra ventrally, much waterworn. The centrum of the pen-- ultimate is twice as long as that of the ultimate, and the neural spine has a greater longitudinal width; this may be due in some: degree to pressure, for this vertebra is much distorted by having been squeezed against the proximal end of the wing-metacarpal which was lying upon it. These vertebre are shorter and more robust than the cervical above described: they appear to be procelous. The neural spines are much thickened, especially at their dorsal extremities. The neural arches slightly overhang the centra. The transverse process of the lett side of the last cervical is preserved. It shows that the transverse processes were produced outwards, as far as those of the notarium which follow it. They are sent off from the anterior half of the centra. These processes. underlie the prezygapophyses, which are produced anteriorly ; they are situated at the base of the neural arches, in front of the neural. spines. The postzygapophyses are directed backwards, and over- hang the posterior end ot the centrum, thus forming a space into. which the prezygapophyses of the following vertebra enters. The hinder ventral border of the last cervical on the left. side has a short, fairly strong, posteriorly directed process, free from the articular: surface of the centrum, the hinder extremity of which probably possessed an extra articular facet (exapophysis) as in Ornithostema: (Pieranodon). An ovate pneumatic foramen lies under the lateral base of the neural arches. The Notarium. The notarium (Pl. XXXVIII, figs. 3, 4, & 5) consists of six anchylosed vertebre. The neural spines are fused into one- strong ridge, which, above the first vertebra, is broader than the- neural spine of the last cervical; it diminishes rapidly, until half as thick over the second, third and fourth, expands again at the fifth and sixth, where it is a third greater than at the anterior end,. and becomes remarkably bulbous. There is no supraneural plate, and the surface of the bone shows no trace of such having come- away. The dorsal outline of the fused spines is highest between the third and fourth vertebra, as in Ornithostoma. The facet for the scapular articulation was probably beneath this, where on the right side there is a depression (Pl. XX XVIII, fig. 3, fa.), which,,. By, Met ia SEF Vol. 69.] SKELETON OF ORNITHODESMUS LATIDENS. 383 however, is not seen on the left side; but this may be due to pressure. The neural arches overhang the centra, forming a ledge along the median region of their sides. The surfaces of these arches are alternately concave and convex in antero-posterior extent. The convexities occur where the zygapophyses have fused, and underneath these a series of fossee are found (Pl. XXXVIII, fig. 5, #., F.). Of these fossee that of the first vertebra is the largest, the others decreasing in size to the last vertebra. Probably pneu- matic foramina occur within the inter-vertebral fossze, as they are not present elsewhere. On the dorsal surfaces of the. transverse processes, the matrix is too hard, and they themselves are too fragile, to permit of its removal, and this is so likewise between the hinder three ; but their ventral surfaces have been fully exposed. These processes arise partly from the neural arches, and partly from the centra. In the first notarial vertebra, as in the last cervical, they originate on the anterior half of the centra, and gradually extend more and more on each following vertebra, until in the fifth and sixth their bases occupy the length of the centrum. They are entirely free, one from the other, and are directed slightly upwards. They are arranged in three pairs, and each pair is different in size and form. ‘The first pair are expanded at their bases and outer extremities, and contracted medially. ‘The middle pair are weaker and shorter than the others, and their distal borders are produced posteriorly into a style-like process. he ultimate pair are con- siderably broader than the rest, are quadrate in shape, and are as long as the first pair. ‘heir ventral surfaces are concave, with a curious downward turning of the anterior edge. This is also seen in the transverse process of the fourth vertebra. The spaces between the transverse processes are greatest between those of the first and second vertebre ; between the others they decrease, until between the last two the division has become narrow. ‘he centra are comparatively small; their ventral surfaces are convex from side to side, and feebly concave longitudinally. The first three show a lateral concavity, the last are free trom any, grooving. On the hinder, lateral, ventral borders of the centra of the first three vertebrae, at their point of union, occur protuberances ; these: I take to be parapophyses. c The Dorsal Vertebre. The dorsal vertebre are six in number and amphiplatyan.. They decrease very rapidly in dimensions backwards. The neural spines are thinner, not so high, and the neural arch less expanded than in the notarial vertebrwe. The transverse processes, instead of occupying a horizontal position, as in the vertebre of the notarium, at once begin to assume an upright one, until in the fourth they are nearly vertical. The centra are convex from side to side; but, through the raising of their anterior and posterior edges, they are: longitudinally more or less concaye. 384 MR. R. W. HOOLEY ON THE [June 1913, The Sacrum. Unfortunately, only the fused centra of three, and a portion of the fourth, sacral vertebrae are preserved. They gradually lessen in dimensions posteriorly. The bases of the transverse processes are all that remain, and it is impossible to determine the form of the sacrum. Vertebral Ribs. Vertebral ribs were lying among the bones near the notarium. ‘They were much waterworn. They are short, small, and hollow, and are two-headed as in other Ornithosaurs. The Sternum. There is no styliform anterior process of the sternum (Pl. XL, fig. 3) such as in all other types is greatly prolonged anterior to the coracoid facets. The keel is as remarkably developed as in the carinate birds. The anterior border is almost vertical; although, ventrally, it bulges slightly in front of the coracoid articular facets. The longitudinal outline rises posteriorly with a sharp curve, and has a greater length than depth. At the posterior end it is a little blunted, by the breaking-away of the rind of the bone. It is very robust, especially at the anterior end. In the lateral median region it becomes gently concave. The base of a strong bony process occurs near the centre of each lateral border, and appears to have been produced upwards and dorsally to them. Although the edge of the lateral expansion is broken away, the converging surfaces of the bone are divided by so narrow a space that they could not have been produced more than a fraction farther. Through this the costal facets are not seen. If they were present, they could only have occupied 18 mm. of the edge, for the rest of the border is too thin and angular for the sternal ribs to have articulated there. The dorsal surface is coneave. There is a broadening of the fore part of the keel for the coracoid facets, which are placed below the sternal plate (Pl. XL, figs. 3 & 4, cor.ar.fa.). The right coracoid facet is situated 20 mm. below the sternal plate and 42 mm. above the ventral outline of the keel. In Seeley’s figure of this sternum the coracoid facets are incorrectly depicted as being on the same plane as the lateral expansions. ‘The facets are oblique, the right ventral to the left. They “were continued on to the lateral surfaces of the keel: ventral to each is a well- developed wing of bone, preventing dislocation of the coracoids. At the posterior termination of each of these is a cavity, determined by Seeley to be pneumatic foramina. This may be so, but they are also cavities into which the hinder point of the distal articular eud of the coracoids entered when the movements of the wings caused these bones to be at their utmost posterior limit, the walls of these cavities acting as stops. The articulations are pulley-joints. I estimate the true length of the sternal plate to have been 65 mm., and the breadth 44mm. A restored outline, of half the natural size, 1s given in Pl. XL, fig. 5. 1 ‘Dragons of the Air’ 1901, fig. 67 & p. 175. Vol. 69. ] SKELETON OF ORNITHODESMUS LATIDENS. 389 The Appendicular Skeleton. The Pectoral Girdle. The scapula and coracoid are strong bones. ‘The former is shorter than the latter. The scapula is fused to the coracoid; the line of ‘suture is horizontal, and both bones here are truncated. Only the preaxial half of the proximal end of the scapula is in union with the oracoid, and here it is bulbous; whereas the free portion 1s com- pressed dorso- -ventrally, and set at right angles to the glenoid cavity. Its articular surface looks downwards, eal forms an steal elenoidal surface (Pl. XXXVIII, fig. 7, ad.ar.sur.). The articular surface of the fused portion is mane: The glenoid cavity is saddle-shaped. The dorsal surface is convex and the ventral flat, but both become concave near the glenoid cavity. The bone here shows a quac- rangular section. The preaxial border immediately behind the glenoid cavity is deeply emarginate, followed by a strong convexity (the acromion process), and that again by a concavity to the distal end. ‘The postaxial border is very concave over its whole length. ‘The distal extremity is considerably expanded; the vertebral margin has a concave facet, apparently for articulation with the notarium. The postaxial border of the proximal end of the coracoid is bent downwards into a kind of lip with a convex articular surface. ‘The coracoid is moderately curved. It is expanded at both ends pre- postaxially and compressed in the central region of the shaft, the preaxial edge traversing postaxially across the bone, until at the sternal end it is in the centre of its ventral surface, which gives the appearance of a twist to the bone. Its sternal articular face is concave pre-postaxially, with its preaxial border ‘produced distally more than the postaxial. Anterior to the glenoid surface of the coracoid there is a triangular inarticuler portion, the apex forming the border of the bone. It is produced into a tubercle, between which and the scapula is a groove, which leads into a pit or pneu- matic foramen, situated at the base of this triangular area, near the articulation. The Humerus. The proximal condyle of the humerus is of the usual Ornitho- Saurian character, feebly convex on its articular surface, and crescent-shaped in outline, with the horns well splayed out. Near the dorsal border of the preaxial side of the articular surface of the condyle is a strong ridge. ‘he deltoid crest is remarkably developed. It springs powerfully. from the preaxial border, at ‘some distance below the head, and curves spirally round the bone until its apex is over the middle of the ventral surface of the shaft. This spiral curve commences 40 mm. from the proximal condyle, and terminates 125 mm. from it. Along its outer curve it measures 75mm. At its distal end it is 27 mm. above the surface of the shaft. This extremity is claw-like, the point directed postaxially, 386 MR. R. We HOOLEY ON THE [June 1913,. quite different from those of the other genera where the distal end is more or less obtuse. The ulnar crest is moderately developed. Between the deltoid and ulnar crests the ventral surface of the bone is concave, but becomes convex as soon as the radial crest is passed. The shaft gradually decreases in size until, in the median region, it has a diameter of 22 mm.; from here it rapidly expands. to the extremity, where its pre-postaxial diameter is 64 mm. The bone here is triangular, the apex being on the median line of the dorsal surface. Immediately underlying the apex on the articulation there is a large circular opening into the shaft (Pl. XXXIX, fig. 3, f.). A. Goldfuss, Nova Acta Acad. Leopold.-Carol. vol. xy (1831) pt. 1, pls. vii & viii. 6 « Reptilien aus dem Lithogr. Schiefer d. Jura’ 1860, p, 43. Vol. 69.] SKELETON OF ORNITHODESMUS LATIDENS. 405 The keel of the sternum of Ornithosaurs had apparently a totally different morphological origin from that of birds. Most authors have thought that the anterior spine is homologous with the inter- clavicle; some aver its homology with the episternum of crocodiles and the manubrium of birds. ‘The facts certainly appear to prove that it is the interclavicle, primarily of dagger-like shape, and occupying, with its posterior end, the ‘ primordial cleit’ of the sternum, and that the coracoids rested directly on the dorsal surface of the spine with the scapule arched in the primitive position towards the vertebral column. Under the influence of flight, the interclavicle became arched in front and gradually pushed back- wards, until we find it in Ornithodesius vertically at right angles to the lateral expansions, instead of on the same plane, and thus occupying the same position as the keelin birds. As the inter- clavicle bent posteriorly under the pressure, tlie coracoids worked their articular facets at first to look obliquely outwards and at last laterally, thus rendering possible movement from in front to the side, and bringing the free ends of the scapule into conjunction with the neural spines of the vertebre. There are several examples of the interclavicle retracting in a forward direction, until but a vestige remains—caused mainly, I believe, by the action of swimming, the limbs with their backward thrust stimulating the forward thrust of the ends of the coracoids, until they united, thereby squeezing out, as it were, the inter- clavicle. In the Ichthyosauride the coracoids are in conjunction behind, and separated in front by the interclavicle; and in the Plesiosauride the coracoids, with the exception of an anterior fissure, united through the greater part of their length. They only require the keystone of the interclavicle, which undoubtedly in an earlier ancestor, at least, divided both the pre-coracoids and the coracoids. In the Nothosauride the coracoids unite in the median line, without a cleft, the vestige of the interclavicle being found as a keystone at the united end of the clavicles, the ‘ omo- sternum’ of Hulke. In birds the articulation of the coracoids on the grooved antero-lateral margins of the sternum is reptilian ; while in Ornithosaurs it is on the interclavicle, which is neither reptilian, nor avian, but ornithosaurian, and a unique modification. The Shoulder-Girdle. Scapula and Coracoid. In Scaphognathus, Dimorphodon, Pterodactylus, and Rhampho- rhynchus the shoulder-girdle is more primitive than in Ornithodesmus, Ornithostoma, or Nyctosaurus, lacking the high specialization of these genera, and more or less retaining’a splint-like form. Remarkable variation in detailed characters is found in species of the same genus, as, for example, Pt. swevicus and Pt. longicollum. The main difference between Oriithodesmus and Ornithostoma and Nyctosaurus is the rather slender process in the two last-named described by 406 MR. R, W. HOOLEY ON THE [June 1913, Prof. 8. W. Williston* as found in the inner angle of the fused bones enclosing aforamen. He mentions, too, that a similar process and foramen are seen in a Cambridge Greensand example described by Owen,” who assigns this girdle to Pterodactylus sedqwicki (syn. Ornithocheirus sedgwicki Seeley sp.). Dr. Plieninger * also notes its occurrence in Pt. swevicus. ‘The foramen seen in these specimens is clearly the remnant of a cleft that once existed between this process and the girdle, and there is much to be said for Prof. Williston’s suggestion that it is ‘possibly a vestigial clavicle.’ If I under- stand correctly, the line of union between the scapula and the coracoid in Ornithostoma runs horizontally across the glenoid cavity. In that respect it is similar to Ornithodesmus and Nyctosaurus, and different from both these in the line being transverse and like a Cambridge Greensand example figured by H. G. Seeley.* The Humerus. The great development and spiral curve of the deltoid crest distinguishes Ornithodesmus from all other genera. ‘The only humeri that I can discover which have a somewhat similar spiral curve, although in not so great a degree, are those from the Lower Chalk of Bluebell Hill, Burham (Kent), in the British Museum (Natural History), and numbered respectively R/1935 and R/1357. The very high specialization of the distal end cannot be compared with that of any known genus. The distal end of a humerus R/37 in the same Museum approximates to it. Distal ends of humeri from the Cambridge Greensand, in the Sedgwick Museum, show it in an incipient degree. The German forms, where the distal end can be examined, possess a trochlear joint with the radial condyle greater than the ulnar. The large circular foramen on the articular surface of the distal end of the humerus of Ornithodesmus is certainly very curious. Possibly a synovial gland was located here. It is represented by a pit or depression in Ornithostoma.’ . The Radius. The remarkably reduced dimensions of the radius, when com- pared with the ulna, form a unique character. It is an interesting parallel modification with birds. The proximal articulation is more specialized, and consequently differs from the simple and almost flat articular face of the proximal end of the radius in 1 ‘Osteology of Nyctosaurus (Nyciodactylus), &e.’ Field Col. Mus. Publ. 78, Geol. Ser. vol. ii, No. 3 (1903) p. 140; also ‘Restoration of Ornithostoma (Pteranodon)’ Kansas Univ. Quart. ser. A, vol. vi (1897) p. 43. 2 « Foss. Rept. Cret. Form.’ (Monogr. Pal. Soc.) 1859, Suppl. i, p. 14. 3 ¢ Pterosaur. d. Jura Schwabens’ Paleontographica, vol. liii (1907) p. 268. 4 «The Ornithosauria’ 1870, pl.i, fig. 10. 5 §. W. Williston, ‘Osteology of Nyctosaurus (Nyctodactylus), &e.’ Field. Col. Mus. Publ, 78, Geol. Ser. vol. ii, No. 3 (1903) p. 142. Vol. 69.] SKELETON OF ORNITHODESMUS LATIDENS. 407 other genera. Probably it will be found that the decussation of the ulna by the radius is not peculiar to Ornithodesmus. It certainly occurs among the Cambridge Greensand specimens. In the distal ends of the radius and ulna of Pterodactylus compressirostris from the Chalk Pit, Burham (Kent), which have been figured by Owen,’ the radius is seen decussating the ulna. On the first plate the ventral, and on the second the dorsal, surfaces of both bones are exhibited. Seeley * has called attention to the fact that the fossil in fig. 1, pl. xxiv of Owen’s ‘ Cretaceous Reptilia’ is ‘ figured for the humerus’ and, further, that ‘the less well-preserved bone in that figure exhibits the ulna in its true position behind the radius’ : this, I think, should read, ‘ the radius in its true position behind the ulna.’ In view of the similarity of the humeri from this chalk- pit, there cannot be much doubt that they belonged to the genus Ornithodesmus. In the reconstruction of the hand of Rhampho- rhynchus kokeni by Dr. Plieninger, the distal end of the radius is partly behind the ulna, but in all other figures of restorations the radius is placed at its distal end parallel with the ulna. These reconstructions have been made from specimens in which the bones are compressed and displaced. The fact that proximally the radius is in front of (ventral to) the ulna has long been known. As the distal end of the radius gradually worked into a dorsal position, either the proximal carpal expanded dorsally for the new articulation (the ulna by expansion at the distal end taking the place of the former radial articular surface), or at one period the radius articulated with a separate carpal, which, under the same influence, followed the radius, and became fused on the original dorsal surface of what is now the one proximal carpal bone. The latter, I think, was the case. The radius and ulna are not separated in the central region of their shafts, as in birds. The Ulna. The ulna is more reduced in the median region of the shaft, more expanded at the extremities, and has more highly-specialized articulations than in any other known example. The proximal arti- culation is far removed from the trochlear joints of the European and American specimens ; but some of the Cambridge Greensand specimens included in the genus Ornithochevrus exhibit it, although either in an incipient or in a degraded stage. The Pteroid Bone. Dr. Plieninger * says that, in the long-tailed forms, the pteroid is a short compressed rod, in the short-tailed forms slender and thin. Ornithodesmus possessed the type of the long-tailed forms. 1 «Foss. Rept. Cret. Form.’ 1851-64 (Monogr. Pal. Soc.) pl. xxiv, figs. 1-2 & pl. xxx, fig. 5. 2 APLULL GT + Bla lan) 2 APU + lopag-qug > suuary ALR -quys > suntan) = ATR : Lapag-qug : sntay > ATIUB : SNUAaX) ATuMe T-qug : SNUAX) Ayre q-qus ? ATW i JapIg-qug ‘ege ‘d (Lo6T) my ‘Toa ‘vorypdeaSozuoaeg “snyoulysoyduny yp ssnyjouboyd poy “sn yQvUubh.cocy ‘snyqoubophduny “uopoydtour(y a prypoudt Lord we yyy ‘vaproyoud qoyd ULBY YL *(snphjyoppopzoiay) snin psopah xT *BULIMVSOJOA N ‘NO pOUnLe7 T *sndayaoyqUlo “MULITLITIOU JULIE) “KPLULITOOTILULE, “sn NjIDPOLI7 T ‘eprpsqoepo.ta) 7 *BaplopAjoUpo.ta} f SUICEMTPIG Bln “p TITUMUVSO199 2) @ Gtr : BLIUaL) > APLULB YT ? LOpPlO-qug : sna ATM -qug : BlIaL) ATU Y-que + ATL > shulat) > ATLUE 2 Laplg-qug , LOSUIUITT XITOT “GHAVdNOO SNOILYOIMISSVIN INGOaY “eo-8er “Ad (e061) @ ‘ON “Tt [oA “tag ‘ToaH ‘g/ TQU ge SUN “[O/) plat CO" ‘(sujhzonpojzah pr ) sninvsopohyy Jo AsofoajsQ ayy UO, 1 * (ULORSOYRIUIC) Uopown.iag T *SNLVAYIOYINUAGC, ? BAIN) SULTS JIA + ApLWMBT-qug “SPLILayooygLuagc, > ATLUIE “BaplojAJoVpolejq + tapag-qng v UOFSTITEM “M 'S 418 MR. R. W. HOOLEY ON THE [June 1913, VI. Measurements IN MILLIMETRES. Breadth of the muzzle 25 mm. from the tip .............2.0.---0-+- 40 Depth of the same at the same point ...................0.eeeee ee eees 40 Breadth of the skull at the centre of the upper border of the OTDULS Sin Aah laciecoet, Seiniase za ecto en eo shine seek ace ee si ae eta oe Reale Breadth of the skull at the posterior end of the maxille......... 99 ID yeyowlar aig Werey SeywaVss |KO oe soasadeudaqcacénoda~eocecnewasanconsusencns0e 83 Breadth of the cranial roof between the supra-temporal pits ... 16 Breadth of the skull between the centres of the squamosal bars. 90 Greatest breadth of the brain-capsule .................2ssseee--sse0ee0 58 Depth of the supra-temporal pits from the cranial roof to the Squamrosall oarinte sacs te lsen ose tee oak amen nee einen meee Sree 35 Depth of the occiput, summit to lowest outer angle of quadrate. 62 Width of the occiput across the foramen magnum ..............- 73 Commencement of anterior nares from the tip of the beak ...... 95 Leecher aye (ING) GANTT JOON Goccocsecaacacnacensssbsecbocesacaceotobe0s 9 Breadth at 140mm. from the tip of the muzzle (line of fracture). 20 Vertical Giameterof the! Orbitsie..en2--)-ee-seee- ee seee=e nese eee ee 30 ANOEIRO OOO MMOT? CUTIE!“ eqncesassooouanesocesaossnesac0cencncraeane 38 Length of the infra-orbital vacuities ............ Ee he Nae amperes 80 Greatest breadthvol thevsamie :/i5. 0: .-ses-4es sec ses: spe ceesse-s- seed ee 12 Length of the infra-temporal vacuities ..............2.2-2-20eseeeee 95 ‘Breadth ofjsbhe same ue... sees kce er shew bees Mace ceence penser ote 17 Distance of the quadrate articulation in fr ont. of the orbits ...... 99 Depth of the same below the dorsal outline of the beak ......... 89 Depth of the palate, below the dorsal outline of the beak, 51 mm. from the anterior border of the nares ..................c0eeeeeeseee 28 Height above the ventral edge of the mandibles when the jaws are closed, 51 mm. from the anterior border of the nares ... 26 Length of the alveolar tract of the upper jaw ................2...- 85 Length of the alveolar tract of the lower jaw................-....++- 94 Theerayetslhy, OVE WaVe) BNAWEIOT WEEN Gon ccacanscodsnscdnesecuebasroceocucoentcce 8 Greatest ibreadthyotatineysamle mee sssssees sees eeey see eee ee eeneeseenoe ts 4. Length of the posterior teeth .1.......02......-ceececeesenersececeseees a Greatest breadth of the same ..............02.0.0..000 ss a eee w Length of the mandibular symphysis .................-.ee.eeseeeee ee 7 Length of the centrum of a cervical vertebra ..............-.--0-+-+- 53 Width between the exterior borders of the prezygapophyses of thevsame: |, ge ks tesa eh... vues see eee RUN ce clsee seas 40 Width between the exterior borders of the postzygapophyses of the same yo eesA eo eee diaied saci oasnahe aepee see PREM SEES ORE 48 . Length of the dorsal edge of the notarium ........................ 110 Length of the ventral edge of the same ...............2-2ceceeseeeeee 105 Length of the centrum of the first dorsal vertebra ............... 14 Length of the scapula, from the glenoidal cavity .................. 90 Depth of the distal end of the same ..........2.........0.022-000--e- 23 Pre-postaxial diameter of the scapula: humeral end............... 40 Ditto SKCOKAC OLA! ake BALM tas uscs ae. Meare nae etaaetone set cE eRe RE Te 33 IDYERH OLN) GOREKGONG| sconce on snaaasooaadascos nbaocaosesneqcseoocesN5000" 113 Antero-posterior diameter of the sternal end of the coracoid ... 27 Ditto, ccentre ob shatt fae sees echoes ooo eet ieeeneereetine 6 Length of the humerus (proximal to distai condyle) ............ 220 Pre-postaxial diameter of the proximal end of the same ......... ol Drtto: cent revok shat ences meee cea oosaee ees eee eee ee 22 ID igo Git tiie GELENEMNGl. 55560 osacboddaadessondeaacaseassnonae dees oos9gc4bN 64 Spiral curve of deltoid crest begins below the proximal articu- lationsolMUMerusi! 5s -cicesseeecte dete cen seneeeene be reece eee ccaet 40 Length of the same along its outer curve ..............,2e0eeeeeeeee 75 Depth of the same from the distal point to the shaft of the MM ETS VCE cate Nae ene conten atte neni ete oneness naan 27 i Vol. 69.] SKELETON OF ORNITHODESMUS LATIDENS. 419) Pre-postaxial diameter at the proximal end of the radius ...... 30 Plc rserme abet, OUSbp) TEC: | 5) Js! sas ansdacveesdosseer cece acesuscatves 38 The same at the centre of the shaft ...............cccececeececseseceees 7 Pre-postaxial diameter of the proximal end of the ulna ......... 60: Mire/samioratybherdistHl em) oe ce oessnnseceeodeneccigeerc-acesert seco 52 The same at the centre of the shaft..................--ssscecesssseeeee 19 Merc iapo tb benppevoldnn. cei teccs tees -nisccocce= cecloncb hicouseo owe Meeieedy 96 Breadth of expansion at the proximal end of the pteroid ....., 10 Menpth) of thellateralicampall (oo... 022 es-scec-sceceeen-eceronceccees-necs 25 Pre-postaxial diameter of the proximal carpal ..................... 49 Pre-postaxial diameter of the distal carpal ...................42 Faas Wt ae Meme VlaVOlpbaeCrCAnOUSte sice cepalgeceducejac-sedeta notes luleacliice Lee eaere esd 28 Pre-postaxial diameter of the proximal end of the wing- IME DACALP Alnor pense esehaes a gevcsn ccs nseresecuceccctnuds ovsine velenssiese D6 Length of portion of the proximal end of the first wing-phalange, PAG erie ys pe rimneny NOs Miao nada eewccusassacctidteuee acs: « 318: Dorso-ventral diameter of the proximal end .................-....6. D4 Dorso-ventral diameter of the distal end .....................0e0 ee 44 Dorso-ventral diameter of the proximal end of the second wing- Rover ean eg yt coerce Maslak sats memercinces ones suhieteae sete eee cmectaua ans neea 44 Length of the proximal portion of the third wing-phalange, NUetHS I SPECIMENPNOL LY Uxntrasn.-aewaascecncascdreueete suave. oie 127 Meucthhotthesternalplatonm-essacessueccetectssetecepecse ey cendctaies 65. HE reActhiOftle/samMowaesrstcencssesnsentdosetacsecoutesseectedasaahacs sean 45 Menotrotethepkeelljasom ccsssc stata sacatautmalievcoteee ecendoseeeaaeysetesl 70 Weptilte ofepiier samme even cteeyeoues escenc asin camse Vou lunacy «clskinban Weleda 60: Depth of the ischium from the acetabulum to the anterior OMA aT CLO ME answer autnaciieeclassapwoutart vie nsadaun-atciateyies tua esaess 76 Length of the femur as preserved. (Distal end slightly water- worn, but showing thickening for the articulation.) ............ 200 Pre-postaxial diameter of the centre of the shaft of the femur... 9 Dorso-ventral diameter of the same .............sssseeseeeeseeneceee 12. The following measurements have been obtained by accepting 89 mm. as the length of the missing block from Atherfield specimen No. 1 :— meng thwotithe skull tas essiee oot ee nese sousece donee mee ecer ec eeetees 560 Length from the tip of the muzzle to the centre of the orbits... 500 Tae a Oe tas WAAC OISS, - cosnscacadsbodecaonccasceboucncotcéecennedonLe 423 Menetheon the radnus ss tienasco css. snelaessakndecemstaeeen aaaae dese. 368 Menget nvontheyalinay xed eh Se suca wae ae ebiieldcaepieseciiseeensesss dens 381 Length of the first wing-phalange ...............:ecesecececeeeener es 393 Length of the second wing-phalange .............2...cscceeeeeneee ees 388 Estimated spread of wing, from tip to tip, and allowing for the natural CUrVe ...........0.cscccsecsecsecersers about 5 metres. I have much pleasure in acknowledging the ever-ready assistance in the preparation of this paper afforded to me by Dr. A. “ae Woodward, F.R.S., and Dr. C. W. Andrews, F.R.S. Bibliog raphies are to be found in :— KH. T. Newton, ‘On the Skull, &c. of Scaphognathus purdoni’ Phil. Trans.. Roy. Soe. ser. B, vol. clxxix (1888) p. 503. K. A. Zrrrsn, ‘Traité de Paléontologie’ vol. iii (1893). F. Putentncer, ‘Die Pterosaurier der Juraformation Schwabens’ Pale-- ontographica, vol. liii (1907) pp. 210-17. 420 MR. R. W. HOQLEY ON THE [June 1913, EXPLANATION OF PLATES XXXVI-XL. PratE XXXVI. [The right-hand block in figs. 1 and 2 is here exhibited with the matrix yemoved at a different angle from the other block. This block requires-a half- .turn to put the portions of bones thereom in their true connexion with those .on the other block. ] Fig. Fig. Vig. 1. Upper view of Atherfield specimen No. 1, partly cleared of matrix: Su., snout; pr.o., premaxillar bar; wo., dorsal border of the no- tarium; 70., rib; sc., scapula; hu.r., distal end of right humerus; rr., vight radius; w7., right ulna; “w./., distal end of left humerus; 7.l., left radius; w./., left ulna: p.cp., proximal carpal; pt., pteroid ; la.cp., lateral carpal; w.mc., proximal end of wing-metacarpal ; mce., portion of one of the small metacarpals; Z.w.ph., distal end of the first wing-phalange ; 2.w.ph., second wing-phalange; 3.w.ph., proximal half of the third wing-phalange. B.M. R/3877. x about 34. 2. Nether view of Atherfield specimen No. 1, partly cleared of matrix: Sn., ventral view of snout; m2.p., inner view of maxillo-nasal process; mn., portion of the mandible; @.~., portion of right quadrate; @./., portion of left quadrate; ¢.v., cervical vertebre ; no., notarium ; @.v., dorsal vertebre ; 2,7.,right humerus; w.7., right ulna; Aw.l., left humerus; 7./., left radius; w./., left ulna; sc., scapula; p.cp., proximal carpal; d.cp., distal carpal; /.cp., lateral carpal; w.imec., proximal end of wing-metacarpal; Jsch,, ischium ; j., femur; 7é., portion of tibia. B.M. R/3877. x about 3%. Prare XXXVID. 1. Sn., the snout, freed from the matrix: p., premaxilla; 7.v., nasal vacuity; m., mandible. B.M. R/3877. x 3. . Portion of the skull near the orbit: O., orbit; a.o.v., antorbital vacuity; @.0.v.2,, antorbital vacuity No. 2; -2.2,/., infra-temporal fossa; pr.0., premaxillar bar; J., jugal; Qw., quadratojugal ; @., quadrate ; ma., maxilla; mn., mandible; m.a., mandibular -articulation ; 6., rounded boss of bone. B.M. R/3877. x 3. . Left lateral aspect of the hinder portion of the cranium, as preserved . -in B.M. R/176: O., orbit; s.¢.f., supra-temporal fossa; 7.¢,7., infra- ‘temporal fossa; s.¢.b., supra-temporal bar; Qvw., quadratojugal ; -Q., quadrate; Jf, matrix with a fragment of a limb-bone. x 3. 4, Interior view of the right maxillo-nasal process: ma.n.b., part of the maxillo-nasal bar; ma., maxilla; a., line of division between the upper and the lower jaw; m., mandible. B.M. R/3877. x 5. i) (Su) 5. Restoration of the skull, perspective lateral view: 2.v., nasal vacuity ; a.0.v., antorbital vacuity ; @.0.v.2., antorbital vacuity No. 2; 0., orbit ; s.t,f., supra-temporal fossa; 7.¢.f., infra-temporal fossa; p., pre- maxilla ; mn., mandible; ma., maxilla ; mx.2.b., maxillo-nasal bar : J., jugal ; Qu., quadratojugal ; @., quadrate ; s.7.b., supra-temporal . bar; p.f.o.b., post-fronto-orbital bar; /., lachrymal; ., rounded boss of bone. X i. Prats XX XVIII. 1. Restoration of the occiput: p.t.f., post-temporal fosse ; fm., foramen magnum ; ¢., occipital condyle; @.,quadrate. X 3. . Restoration of a cervical vertebra, ventral view. X 3. . Right lateral view of the notarium : fa., the supposed articular facet for the scapula; A, anterior end. B.M. R/3877. xX co bt SIH Fe 5 ecoouieg ‘SNSGILV1 SNWS3GOHLINYO er ae ea Quart. Journ. Geor. Soc. Vor. LXIX, Pi. XXXVI. ae xe, see RD nny hea eee SW Aye 8,0 Quart. Journ. Geo. Soc. Vor. LXIX, Pr. XXXVI. Aqsaq Oj}05 'eSoawag “SNAGILV1I SNWSAGOHLINYO J2P ‘PAEMPOoAA “MD Quart. Journ. Geox. Soc. Vor. LXIX, Pv. XXXVIH. G. M. Woodward, del. Bemrose, Collo, Derby ORNITHODESMUS ESD EINES: Quart. Journ. Geo. Soc. Vor. LXIX, Pe. XXXIX. Bemrose, Collo, Derby. G. M. Woodward, del. LATIDENS. ORNITHODESMUS Quart. Journ. Geor. Soc. Vor. LXIX, Pu. XL. G. M. Woodward, del. Bemrose, Colle. Derby. ORNITHODESMUS LATIDENS. Vol. 69.| SKELEION OF ORNITHODESMUS LATIDENS. 421 Fig. 4. 5. Restoration of the notarium, right lateral aspect: F, F, Se: 6. 7 i) (oe) a~ ~ er) 10. Fig. 1. s Upper view oh ee specimen No, 2: h.r., distal end of the right . Restoration of the dorsal outline of the sternum: A, anteriorend. xX . The right ischium : ac., part of the acetabular rim. B.M.R/3877. x . The right femur, distal end partly destroyed: B.M. R/3877. x 3. .Y Ventral view of the notarium: 4A, anterior end. x 3. Ja, facet for the scapula; A, anterior end. x §. Inner view of the left scapula, sins a moiety ot the ens endl gl., glenoid cavity ; a¢c.pr., acromion process. B.M. R/3877. x i. . Humeral end of the right scapula and perfect coracoid: sc., apm end of scapula; cor., coracoid; g/., glenoid cavity; ad.ar.sur., ad- ditional articular surface, placed at right angles to the glenoid cavity. B.M. R/3878. x 4. : Pruate XXXIX. 3 . Portion of the right humerus, exhibiting the spiral curve of the deltoid crest: dl.cr., deltoid crest; /., fragment of bone attached to the shaft of the humerus. BM. R/176. x 3. . Restoration of the humerus: d/.cr. deltoid crest ; ¢p., an epiphysis overlapping the shaft; 77., ridge for muscle-attachment. <2. . Distal articulation of the lett Malin : f., circular ees into rlreie tr., trochlea for the radius; v., valley for the ulnar ridge. BM. R/3877. x 3. Proximal articulation of the left ulna: JZ?., transverse ridge for arti- culation in the valley on the distal articulatory surface of the humerus. B.M.R/3877. x 5. . Dorsal view of the right radius and ulna, showing decussation : f., vadius; U., ulna; 77., ridge. B.M. R/38877. x F. Ventral view of dhe left raeni and ulna: &., radius; U., ulna; Ja, articulatory surface articulating with the proximal carpal; , ridge. B.M. R/3877. x 4. Distal articulation of the ‘tifa A, circular pit; 2, oval convex condyle; C, articular surface prolonged on to the shaft of the ulna. B.M. R/3877. x 4S. Proximal articulation of the proximal carpal: A, hemispherical knob; B, oval concavity ; C, articular surface for articulation with that on the ulna marked Cin fig. 7; D, elongate cavity for the radius; EF, small coneavity. B.M. B/3877. x Se . Distal articulation of the distal carpal: 4, articular facet below the main articular surface; B, main articular surface; C, articular sur- face for small metacarpals ; J, deep circular cavity. B.M. R/3877. ao Proximal articulation of the wing-metacarpal: 4, articular facet below the main articulation ; BL, main articular surface : C, the position of the small metacarpal is se heea this space. B. M. R/3877. x . Prats XL. Right pteroid bone: B.M. R/s877. xX 5. humerus ; , proximal end of the right radius ; u.r., proximal end of the aah aia h.l., distal end of the left humerus; /V.inc., distal _ end of wing-metacarpals; s.)., small bone, apparently articulating in semicircular emar gination (. ¢.e.) on the first wing-phalange, 1. V.ph. B.M. R/3878. x 4. . Left lateral view of the sternum: cor.ar.fa., coracoid articular facets. B.M. R/3877. X 5. . Slightly oblique anterior view of the sternum, to exhibit coracoid facets : cor.arfa. B.M. R/3877. x i. teleto| 422 THE SKELETON OF ORNITHODESMUS LATIDENS. [June 1913. Discussion. - The Prestpenr (Dr. A. Srrawan) desired to emphasize the im- portance of the work which had been carried out by the Author for some years past. Not only had a large number of valuable fossils been rescued from destruction by his care and perse- verance, but by his skill in interpreting them conclusions of much interest had been placed before the Society. Dr. C. W. AypRrews congratulated the Author on his success in collecting such beautifully-preserved reptilian skeletons from the Wealden Beds of the Isle of Wight. He remarked that there was some doubt whether the generic name Ornithodesmus was applicable to the species now described, it having been applied originally to a number of fused vertebrae which differ materially from either of the two groups of fused vertebrz in the specimen now under considera- tion. The peculiarities in the arrangement of the temporal arcades and fossz he considered to be entirely due to the nearly antero- posterior direction of the elongated quadrate. The Author’s interesting account of the mechanics of the wing-bones, particularly of the carpal region, could not be profitably discussed in the absence of specimens and diagrams. Dr. A. SuirH Woopwarp expressed his admiration of the Author’s work and perseverance. He hoped that, as soon as the paper was published, the specimens described would be mounted and .exhibited in the British Museum (Natural History). The AvurHor briefly replied. He thanked the Fellows for the kind way in which they had received his paper. He said that the lengthening of the muzzle, as an aid in procuring food, had undoubtedly drawn forward the bones below the orbits. The facial portion of the skull was about 53% times that of the cranial. The © length of the skull was 560 millimetres, and the spread of the wings when curved in flight about 5 metres, «4 ADMISSION AND PRIVILEGES OF FELLOWS OF THE GEOLOGICAL SOCIETY OF LONDON. 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[Postage 6d.] THE CENTENARY OF THE GHOLOGICAL SOCIETY OF LONDON, recorded by W. W. Warts, F.R.S. Price 2s, net. [Postage 3d.] HUTTON’S ‘THEORY OF THE EARTH, Vol. III., edited by Sir ARCHIBALD Gukin, D.C.L., F.R.S. Price 3s. 6d. To Fellows, 2s. [Postage 4d.] THE GEOLOGY OF NEW ZEALAND. Translated by Dr. O. F. Fiscumr from the works of MM, Hocusrerrer & Perermann. With an Atlas of Six Maps. Fellows may purchase one Copy of this Book at 2s. Additional Copies will be charged 4s. [Postage 5d.] CONTENTS. Pages Proceedings of the Geological Society, Session 1912-13 ...............:ceceeee Xeili—xcix PAPERS READ. Page 9. Mr. 8. 8. Buckman on the ‘ Kelloway Rock’ of Scarborough ................- 152 10. Mr..C. Thompson on the Derived Cephalopoda of the Holderness Drift ... 169 11. Mr. C. T. Trechmann on Anhydrite in the Magnesian Limestone at Hartlepool (Plate KX) eis.) estas keeelird case coat eckec secs ceeleeee eee eREee 184 12. Mr. G. A. Frost on the Internal Cranial Elements and Foramina of DO PEdvUs OT AMUNGTUSS vedo. ean cuits file eslece dees vScen cores sae stse ee dae eneeee eee 219 13. Mr. Hamshaw Thomas on the Fossil Flora of the Marske Quarry (Pilates XRT ETON VD) isonet Seen oe eet oven ee seins sy seen ene ee eReeee 223 14. Mr. R. H. Goode on the Fossil Flora of the Pembrokeshire Coalfield (Bla bes PXOXIVA XO KGXG) | eM allude bist tales eioaie ne nienine ea gee eee 252 15. Mr. E. B. Bailey on the Loch Awe Syncline (Plates XXXI & XXXII) ...... 280 16. Dr. A. M. Davies & Mr. J. Pringle on Two Deep Borings at Calvert Sienntosay (EI hits} 9-0-0. 4 ME (03 0.0.0.0 0) sna naacninseanpoesesonsosaeesodsesnccoacscoc 308 17. Mr. J. B. Serivenor on the Geological History of the Malay Peninsula (TENET Fe): @. O..G) EAS ARORE 2AT S R ORRS Ar ORE an mi ae oa esciad 343 18. Mr. R. W. Hooley on the Skeleton of Ornithodesmus latidens (Plates XXX V1I- BAe eee ea io site aa eis btn alana AR cirp ticle ts Matec ea cine ee aie enue ae 372 [No. 275 of the Quarterly Journal will be published next September. | . [The Editor of the Quarterly Journal is directed to make it known to the Public that the Authors alone are responsible for the facts and opinions contained in their respective Papers. | *,* The Council request that all communications intended for publication by the Society shall be clearly and legibly written on one side of the paper only, with proper references, and in all respects in fit condition for being at once placed in the Printer’s hands. : Unless this is done, it will be in the discretion of the Officers to return the communication to the Author for revision. The Library at the Apartments of the Society is open every Weekday from Ten o'clock until Five, except during the fortnight commencing on the first Iionday in September, when the Library is closed for the purpose of cleaning; the Library is also closed on Saturdays at One p.m. during the months of August and September. It is open until Hight p.m. cn the Days of Meeting for the loan of books, and from Hight p.w, until the close of each Meeting for conversational purposes only. Vol. LXIX. OCTOBER 29ru, 1913. No. 275. Part 3. QUARTERLY JOURNAL OF THE GEOLOGICAL SOCIETY. THE ASSISTANT-SECRETARY. [With Ten Plates, illustrating Papers by Dr. H. Salfeld, Mr. H. Kay, Dr. A. Jowett, Mr. M. per and Dr. C. A. Matley. | ba LONDON: LONGMANS, GREEN, AND co. -— PARIS :—CHARLES KLINCKSIHCK, 11 RUE DE LIULE. SOLD ALSO AT THH APARTMENTS OF THE SOCIETY. Price Five Shillings. OO OO Oa a aes LIST OF THE OFFICERS AND COUNCIL OF THE GEOLOGICAL SOCIETY OF LONDON. nnnness VY nanan aS Presivent. Aubrey Strahan, LL.D., Sc.D., F.B.S. WicesPresiVents. Prof. Edmund Johnston Garwood, M.A. Richard Dixon Oldham, F.R.S. Clement Reid, F.R.S., F'.L.S8. Prof. W. W. Watts, LL.D., Sc.D., F.R.S. Decretarics. Arthur Smith Woodward, LL.D., F.R.S. Foreign Secretary. Sir Archibald Geikie,K.C.B.,D.0.L.,LL.D., Sc.D., Pres.R.S. Cou Henry A. Allen. Henry Howe Bemrose, J.P., Sc.D. Prof. Thomas George Bonney, Sc.D., LL.D., E.R.S. James Vincent Elsden, D.Sc. John William Evans, D.Se., LL.B. William George Fearnsides, M.A. Prof. Edmund Johnston Garwood, M.A. Sir Archibald Geikie, K.0.B.,D.C.L., LL.D., Se.D., Pres.R.S. Prof. Owen Thomas Jones, M.A.,-D.Sc. Herbert Lapworth, D.Sc., M.Inst.C.H. Bedford MeNeill, Assoc.R.S.M. Horace Wollaston Monckton, Treas.L.S. | Herbert Henry Thomas, M.A., B.Sc. Creasurer. Bedford McNeill, Assoc.R.S.M. NCIL. Edwin Tully Newton, F.R.S. Richard Dixon Oldbam, F.R.S. George Thurland Prior, M.A., D.Se., F.B.S. Clement Reid, F.R.8. FE. L. S. Aubrey Strahan, TDs Se.D., F.R.S. Herbert Henry ‘barns, MA. B.Sc. Arthur Vaughan, M.A., D.Sc. Prof. William Whitehead Watts, LL.D., Se.D., M.Sce., F.R.S. William Whitaker, B.A., F.R.S. ; The Rey. Henry Hoyte Winwood, M.A. Arthur Smith Woodward, LL.D., F.R.S., E.LS. Assistant-Secretarp, Clerk, and Librarian. L. L. Belinfante, M.Sc. Assistant-Librartan. Assistant=Clerk. C. P. Chatwin. M. St. John Hope. Assistant in @flice and Lidrarp. Arthur Greig. STANDING PUBLICATION COMMITTEE. Dr. A. Strahan, President. Dr. A. Smith Woodward, de Mr. Herbert H. eet SERED Mr. H. A. Allen. Dr. J. V. Elsden. Mr. W. G. Fearnsides. Mr. H. W. Monckton. Mr. H. T. Newton. Dr. G. T. Prior. Dr. G. J. Hinde. Dr. H. Lapworth. Dr. A. Vaughan. Mr. Bedford McNeill. Prof. W. W. Watts. EVENING MEETINGS OF THE GEOLOGICAL SOCIBTY TO BE HELD AT BURLINGTON HOUSE. Session 1913-1914. Mr. Clement Reid. 1913. Wednesday, November ............-.-++- 5*—19* Bs December! ee sseeeaeeee 3 —l17* 1914. Wednesday, January ...........-00+00000 7*—21* “f February (Anniversary, Friday, Feb. 20th)...... 4*—25* 4 Marche eyecare cin ee 11 —25* » Avril pee eee an ee ane 8 —29%* ob May tiiccnaacncanatacnentn set 13 —27* SUT Ws een HN OE RD er 10 —24* Basis will commence at Hight o Clock precisely. | The asterisks denote the dates on which the Council will meet. ‘Vol. 69.] > CERTAIN UPPER JURASSIC STRATA OF ENGLAND. 423 19. Certain Upper Jurassic Srrara of Enetanp. By Dr. Hans SaLFELD, University of Gottingen. (Communicated by S. S. Buckman, F.G.S. Read June 11th, 1913.) [Puares XLI & XLII.] “By combining the evidence of a number of sections in England and near Boulogne-sur-Mer I have succeeded in establishing a normal succession of zones in the Oxfordian, Kimmeridgian, and Portlandian rocks, using these terms according to the German and French classifications. Dispensing with See p. 429. Xi 4 P. de Loriol & E. Pellat, ‘Monographie paléont. & géol. des Etages supérieurs de la Formation Jurassique des Environs de Boulogne-sur-Mer ” Mém. Soc. Phys. Hist. Nat. Geneve, vol. xxiii (1874) pl. ii, fig. 1. Vol. 69. ] - UPPER JURASSIC STRATA OF ENGLAND. 495 ‘Yellow Ledge’! the clays contain Gravesie flattened by pressure, those below belonging to the group of Gr. gravesiana d’Orb. sp., those above to the group of Gir. wrius d’Orb. sp. This is of great importance. It is not only that the Gravesia Beds are here recognized in England for the first time,? but we are thereby enabled to fix exactly the boundary between ‘Kimmeridgian’ and ‘ Portlandian’ in the Kimmeridge section ; that is to say, all that follows above the ‘supposed Maple Ledge’ must be correlated with the Portlandian. The clays between the ‘ Yellow Ledge Stone-Band’ and the ‘ Oil-Shales’ form the equivalent of the Virgatites Beds, although I have never found a true Virgatites here. To the same zone we must also assign a part of the overlying clays, Somewhat below the ‘ White Septarian Band, however, we reach the beds with Perisphinctes pallasianus Orb. sp. This zone must be recognized as extending up to the basal limit of the ‘ Portland Sands.’ Blake’s statements concerning the ammonites contained in the Portland Sands and Portland Oolite of Purbeck, and also of Portland, I can, in the main, confirm. In the highest beds of the Portland Sand at Portland I found Perisphinctes gorei sp. noy., which indicates that the overlying Portland Oolite comprises the two zones characterized by Perisphinctes pseudogigas Blake sp. and P. giganteus J. Sow. sp. respectively, as assumed by Blake. We may now consider the exposures in the neighbourhood of Weymouth. The Osmington Oolite yields Pertsphinctes marteili Oppel sp., and accordingly corresponds with the uppermost zone of the Lower Oxfordian. The Sandsfoot Clay, from its position, must correspond to the zone of Perisphinctes warte and Cardio- ceras alternans. Vhe Sandsfoot Grits yield Perisphinctes achilles, P. decipiens, Cardioceras serratum, and Ringsteadiw, thus corre- sponding with the two upper zones of the Upper Oxfordian, Above the Sandsfoot Grits we may place the basal line of the Kimmeridge, lithologically not a very sharp division. The clays and marls which lie above the Sandsfoot Grits contain uncrushed Pictonie. Then follow thinly-laminated clays yielding Rasenia cymodoce and other species, above which are similar beds containing /. mutabilis, all much compressed. The beds with Aulacostephanus pseudomutabihs, A. eudoxus, etc., are exposed in the higher nodular layers. The zone of Aulacostephanus yo, ' For the position of these stone-bands, see A. Strahan, ‘The Geology of the Isle of Purbeck & Weymouth’ Mem. Geol. Surv. 1898, pl. x. 2 The ammonites described by Prof. Pavlov & Mr. Lamplugh from the Speeton Clay as Olcostephanus (Polyptychites) gravesiformis are true Poly- ptychites of the Valanginian, and not identical (as assumed by the first-named writer) with species of the group of the Gravesie from the Gigas-Schichten of the lowest Portlandian of North-West Germany. See A. P. Payiov& G. W. Lamplugh, ‘Argiles de Speeton & leur Equivalents’ Bull. Soc. Imp. Nat. Mose, n. s. vol. v (1892) p. 482. 2F2 426 DR. HANS SALFELD ON CERTAIN [Oct. 1913, as also the Gravesia and Virgatites Beds of the Lower Portlandian, cannot be recognized here, because the section is, to a great extent, obscured by talus. The clays below the Portland Sands here likewise yield Peri- sphinctes pallasianus throughout. The section at Red Lane, Abbotsbury, described by Blake & Hudleston ' (given by them in inverted order of succession) shows in Bed 2 of Blake a dark-brown, richly-ferruginous, soft oolite, containing in abundance Waldheimia dorsetensis Walk., Rasenia thermarum Oppel sp., &. uralensis d’Orb. sp., and other species. These ‘Corallian Beds’ of Blake are, therefore, the exact equi- valents of the Lower Kimmeridge Clay of Weymouth, the zone of Rasenia cymodoce, a fact already recognized by Prof. H. Douville. The exposures near Swindon prove that the Kimmeridge Clay facies, as shown in the clay-pit at Telford Road, extends down as far as the zone of Perisphinctes decipiens and Cardioceras serratum. Below this follow sandstones of the ‘ Corallian.’ Clays with Pictonie are exposed at the base of Buzzard’s Clay-pit in Swindon. The leathery shales at the top of the Lower Clay-pit contain Aulacostephanus pseudomutabilis, A. eudoxus, ete. Since the succeeding clays and marls yield Virgatites, the dividing-line between Kimmeridgian and Portlandian must here be placed immediately above the leathery shales. The Gravesia Beds are here either entirely wanting, or are condensed to a minimum. It is known that Perisphinctes pectimatus occurs in the Portland Sands below the Swindon Clay. The Swindon Clay itself has yielded no ammonite. On the other hand, the ‘Lydite Pebble- Bed,’ immediately overlying the Swindon Clay, contains a new ammonite of contemporaneous age—a Perisphinctes related to P. ulmensis Oppel sp., P. denseplicatus Waagen, and P. post- ulmensis Blaschke—in addition to very numerous, rolled, phos- phoritized and silicified fossils derived from lower horizons, parti- cularly from the zone of Perisphinctes pallasianus. Immediately above, in the base of the calcareous sandstone, Perisphinctes goret sp. nov. is abundant. The main mass of the calcareous sand- stone yields Perisphinctes pseudogigas Blake sp. as the charac- teristic species. The overlying Swindon Sands may be regarded as equivalent to the zone of Perisphincies giganteus, although it has not been possible to prove the occurrence of ammonites in them. It is important to note that, in the Swindon neighbourhood, the sandy facies persists longer than at Portland and in Purbeck. The boundary which is there drawn between the Portland Sands and the Portland Oolite would fall at Swindon in the calcareous sand- stone, above the zone yielding Perisphinctes gorez. At Westbury the top of the Ironstone yields Aingsteadie ; above 1 J. F. Blake & W. H. Hudleston, ‘On the Corallian Rocks of England’ Q.J.G.S8. vol. xxxiii (1877) p. 273. ty Bo Vol. 69.] UPPER JURASSIC STRATA OF ENGLAND. 427 this comes Kimmeridge Clay, which thus probably begins here with the zone containing Pictonie. It can, therefore, be recognized that over the whole region described the change of facies between the Kimmeridge Clay and the Portland Sands occurs at one and the same time, The facies-division between Kimmeridge Clay and Corallian is, however, not chronologically constant, but changes to the extent of several zones even within short distances: thus, for instance, between Weymouth and Abbotsbury, or between Westbury and Swigdon. As regards other localities, I will merely emphasize the fact that the Kimmeridge Clay exposed at Market Rasen (Lincolnstire), which has furnished the splendidly-preserved ammonites that constitute a particular embellishment in many collections, has only yielded the fauna of the zone of Rasenia cymodoce and LR. uralensis. The foregoing account forms the first publication of a part of my comprehensive studies on the zonal subdivision and correlation of the Upper Jurassic formation (in the German sense) of Middle and North-Western Europe. The investigation of the faunas will be dealt with in separate monographs of the genera, to be published in ‘ Paleeontographica.’ Finally, I wish here to express my warmest thanks to all those gentlemen who, by valuable advice and information and by giving access to collections, as well as by the loan of fossils, have supported and furthered my studies: particularly to Dr. A. Smith Woodward, Prof. W. J. Sollas, Mr. G. C. Crick, Dr. F. L. Kitchin,’ Mr. 8. 8. Buckman,’ Mr. Gore, and Mr. Barnes, in addition to others. i Appendix : Ammonite Names. Rinesteapra, gen. nov. Genotype, Ammonites pseudocordatus Blake, emend. Salfeld. Blake’s illustration, in Q. J. G.S. vol. xxxiii (1877) pl. xiii, fig. 1, scarcely reproduces the characters of the genus. Since the original specimen cannot be found, I take as type of the genus that ammonite from the same locality which agrees most closely with Blake’s description. The following must rank as synonyms of A, pseudocordatus Blake, emend. Salfeld :— ; 1888. Ammonites mutabilis R. Damon, ‘Supplement to the Geology of Wey- mouth & the Isle of Portland’ pl. xvi, fig. 1. 1909. Proplanulites mutabilis R. Douvillé, Bull. Soc. Géol. France, ser. 4, vol. ix, pl. vil, fig. 1 & pl. viii, fig. 1. The name is derived from Ringstead Bay, near Weymouth (Dorset). 1 TI am also indebted to Dr. Kitchin for translating this paper, and to Mr. Buckman for bringing together my results in the form of the table which follows (p. 428). uddd{Q) ATMOT ‘gid-AUH PVoyY PLOJ]Ay, “WOpULALG ‘ato-uo FO doy, “6M 480 AA gid AUT) Ss paezzng JO osrg, “UOpULAg ‘a0 WoL, *SMGS}oqQ VY ‘aITTOR WOJZSurwUs tT TUS() "ALID JOoJspueg “MLOFSULUISC, "SLID JOOFSpuRG *HO}.SULUISC) ‘spivm pue s{vpp *U0JSUTUUSC, “sAvpO poy euler "OF. SUITUSE ‘sAvpo poyVuUraUVEy “MOPS ULUSE ” ‘sXBlQ ‘Wasery JOAv IN a agumul SaqOUYASWO apuvay sagour.ydsi.ta 7 “—"" guaidwoop sajzourydsiia gq ‘ sngpplovopnasd npnagshury ee SIpLgvINU YIUWAS0 229 ( rs Of snupydajsoonyny Saw = ) Pale-blue clay with Spirorbis Limestone, and impersistent coaly beds. (4) Sandstones with much included material. 1 (3) Pale-blue clay with Spirorbis Limestone and a definite seam of coal. « (2) Sandstones. «(1) Passage-beds, mainly conglomeratic. (1) The Passage-Beds. Coarse, pebbly sandstones alternating rapidly with bands of »purple marl have been shown (p. 437) to occur at the summit -of the Old-Hill Series. These beds are well developed on Muck- low Hill between the clay-pit and the canal, and a typical exposure is seen in the canal-cutting. The purple bands are here reduced to mere partings, afew inches only in thickness, and the sandstone- layers are highly conglomeratic. A mass of tough calcareous con- glomerate overlies the highest band of marl, but is merely an ‘irregular pocket and not a persistent bed. Between the canal and the railway, pebbly sandstones with arenaceous partings occur, and ferruginous material is plentifully distributed. At the foot of the hill, the Illey Brook flows through a V-shaped ravine in grey sandstone, and forms a fine cascade, which falls into a large rock- “basin excavated through the conglomerates into the alternating ‘beds. 1 «The Silurian System ’ 1839, pp. 54-57. Behe ‘Vol. 69.] SEKIES OF THE SOUTH SLAFFORDSHIRE COALFIELD. 439 No definite line of demarcation can be drawn between the beds with argillaceous partings and those which are wholly arenaceous. The pebbles throughout possess the same characters, and strongly recall the rocks exposed at the Lickey Hills, for they consist of ‘Cambrian quartzites, Llandovery sandstones, and other rocks which are associated with these in that locality. ‘The Llandovery sand- -stone-pebbles are often fossiliferous, and Mr. W. Wickham King has collected typical specimens from them. There is a perfect gradation of the lower strata into the upper, -and I propose, therefore, to group these together under the name of the Passage-Beds. Their total thickness, as seen on Mucklow Hill, is probably not less than 100 feet. The Passage-Beds are well exposed on the summit and eastern ‘face of Furnace Hill. They dip rapidly southwards, and disappear beneath brown and yellow sandstone in a cliff bordering the River ‘Stour below Halesowen Church. North of a line drawn from Furnace Hill westwards to Witley Lodge only purple marls are found, and south of this line only grey sandstones appear. ‘The presence of a fault may, therefore, be inferred. The published Geological Survey maps indicate a -small fault between Furnace Hill and Old Hawne Colliery, while a fault is exposed in the cutting along the mineral railway, imme- diately west of Witley Lodge. In this last exposure Espley Rock, -covered by purple marls, abuts against massive grey sandstones. Still farther west the fault may be inferred, since, at the spot where the road from Halesowen to Stourbridge crosses the Lutley Brook, a deep ravine, excavated in. grey sandstone, occurs on the left hand, while Espley Rock and purple marls are seen on the right. In the ascent of the road towards Colman Hill, the marls are covered by conglomeratic Passage- Beds like those of Mucklow Hill; and these, in turn, pass under the grey sandstones, which occupy the higher ground. Opposite Corngreaves Hall, the outcrop of the Passage-Beds is -eut off by a small fault, but reappears at a lower level in the deep gorge of the River Stour. From this point the outcrop runs westwards through Cradley, where the Passage-Beds form the steep ridge upon which the church is built. On the northern face -of Homer Hill the beds are again exposed, though much reduced in thickness, the pebbles being also of smaller size. On the western side of the hill the beds disappear entirely. In the inclined tramway- cutting at Oldenhall Colliery, grey sandstones rest directly upon somewhat sandy purple marls; and at Ham Dingle, on the margin of the coalfield, the junction of the two series is of the same character. Wherever they occur, the Passage-Beds constitute a perfect eradation from the Old-Hill Series into the Halesowen Series, ‘thus proving that the relation between the two series is one of perfect conformity. The thinning-out and disappearance of the Passage-Beds westwards, however, is a feature of considerable importance, which should be correlated with other facts recorded von pp. 449-51. Q. J. G. 8. No. 275. 26 Fig, 1.—Section through Oradley and Hasbury to Hunnington (AB on the map, Pl. XLI PD, Splat Has bury N.W. Stour Glen Yew Tree Quarry Colman Cradley Church Railway Hunningeton Hill Farm > Permian Hill Lutley Brook R. les Ss Halesowen Coal and Clay: Old Hill Serics ? Old Hill Series Old Hill Series [Scales : Horizontal, 2 inches=1 mile; vertical, 1 inch=750 feet. | (2) The Witley Group. The finest section of the grey sandstones which overlie the Old- Hill Series is found in the cutting: of the inclined tramway at Oldenhall Colliery. The purple marls extend upwards to a small bridge crossing the tramway near the 9500-foot contour-line, and are covered by coarse, brownish-grey sandstone con- taining a few small and scattered pebbles of quartzite. No break occurs in the sandstones, but the- highest beds here seen are finer in texture and lighter in colour than those lower down. In the colliery- shaft, at the head of the incline, 45 yards of sandstone rock were- proved.’ Similar sandstones extend over the area eastwards to Colman Hill and northwards to Homer Hill and Cradley. They exhibit the same- upward gradation in texture and colour. In the Colman-Hill district they contain lenticular beds of dark calcareous sandstone, and ‘ironstone’ is reported from a well-sinking in the same locality.” The dip of the strata at Oldenhallis 15° east-south-- eastwards.° These beds are only a portion of a thicker group, inasmuch as higher sandstones, dipping at 25° west- wards,’ are met with on the western side of the Hayes Fault at Careless Green. Calcareous sandstone also- occurs here, but the general char- acter of these upper beds is that they are fine in texture, greenish in colour, and slightly micaceous. The- colour changes into a pale yellow towards Lushbridge, where clays con- taining a l-foot coal are found at a higher level.* 1 From information supplied by Mr. Bangham, Oldenhall Colliery. 2 Krom information supplied by Mr. Jew, Manager of Witley Colliery. 3 Geological Survey l-inch map, Sheet LXII, 8.W. 4 From information supplied by Mr. Bangham. Sie: ay Vol. 69.] THE HALESOWEN SANDSTONE SERIES. 441 In the ravine below Lutley Mill, sandstones are seen which strongly resemble those -around the shaft of Oldenhall Colliery. In the Lutley Gutter, these pass under fine yellowish sandstone, which in turn underlies blue clay containing a thin coal-seam. In the cutting of the mineral railway below Witley Lodge, the lowest sandstones exposed also resemble those found at Oldenhall, and they occur some 70 feet below clays containing a 2-foot seam of coal. The entire thickness of the group may, therefore, be estimated at not less than 200 feet.’ . In the Witley exposure the beds are seen to great advantage. Quartzite pebbles 1 or 2 inches in diameter are occasionally found. Pockets of ‘ cornstone’ occur, with lenticular beds of calcareous sandstone. Numerous rounded concretions of dark, ferruginous, yet highly calcareous sandstone are also found, and these weather with rusty exfoliating coats. Plant-remains are abundant, and are occasionally well preserved. ‘The most interesting feature of the exposure, however, is the occurrence of big logs of petrified wood, resting upon, surrounded by, and overlain by undisturbed sandstone. Fossil wood of a similar type of preservation was met with in the shaft of Oldenhall Colliery.” These higher beds of the group are found around Wollescote Hall, at Careless Green, in the central portion of the Lutley Valley, and in the districts lying north and east of Halesowen. They occur also below the summit of Mucklow Hill, and are exposed in the brickworks at Blackheath, at Rowley Regis Station, and at Cakemore. Fig. 2.—Section from Yew-Tree Farm to Mucklow Hill (CD on the map, Pl. XLIV). Halesowen Mucklow 4 S.W. Yew Tree Illey Clay Hill N.E, Farm eo Stour Breer Sai Cael Pit H.C.& C, Hasbury Group Halesowen Coal and Clays Witley Group Witley Group Old Hill Series . Cc 2 EM , 1 inch=7950 feet. | [Seales : Horizontal, 2 inches—1 mile ; vertical So far as I am aware, these beds are distinguishable from all other sediments of the Halesowen Series by the combined characters of fine texture, greenish or yellow colour, and the presence of mica. Texture alone is not peculiar, similar colours are seen in other beds, but the presence of mica does appear to be characteristic, and the combination of these characters is distinctive. The importance of this generalization may be seen in the fact that this combina- tion of lithological characters is exhibited by sandstones occurring 1 In Ham Dingle there is present only some 70 or 80 feet of sandstone above . the purple marls, the lower beds of the Witley Group being entirely absent. 2 From information supplied by Mr. Bangham. ee G 442 MR. H. KAY ON THE HALESOWEN SANDSTONE | Oct. 1913, at Rubery, in the stream-course south of the station. From this I infer that these sandstones belong to the highest members of the Witley Group, and in consequence I assign the clays and 2-foot coal which occur on the flanks of the Lickey anticline to the horizon of the Halesowen Coal and Clays, and not to the Llley Group as surmised by Prof. Lapworth.’ (8) The Halesowen Coal and Clays. Murchison’ repeatedly mentions ‘coal at Halesowen,’ but so vaguely that its position cannot be recognized. Jukes* makes no reference to it, although he cites Ham Dingle, the Lutley stream-courses, Uffmoor Wood, and The Leasowes as localities where ‘a thin coal or coals’ may be found. Outcrops of coal are marked at these places on the published maps.* Other ‘ coaly traces’ are known to occur in Wassel Grove Dingle,° in the Hasbury quarries,’ in the ‘ Spirorbis-Limestone Group’ at some point not specified,’ and at Rubery.® It is, therefore, important to ascertain whether these occur at one or more horizons, and in the latter event to distinguish between them. In Ham Dingle the coal is 1 foot thick, and forms a distinct ledge in the stream-course half way up the ravine. It is associated, with yellow (blue where unweathered) clays above and below, and the total thickness does not exceed 10 feet. ‘Traces of coal in a similar position are found in Hodge-Hill Dingle, and an exposure ot coal by the side of a pool in Lushbridge Hollow was pointed out to me by Mr. Bangham. Here the outcrop is eut off by the Hayes Fault, and neither coal nor clay appears north or east of Oldenhall. At Fatherless Barn a fault is to be inferred, since sandstones dipping east-south-eastwards at 15° occur on the north, and horizontal sandstones separated by clays on the south. The clay outcrop can be followed into the ravine known as the Lutley Gutter, where coal is exposed. Clay also occurs in the fields below Lutley Grange, and the outcrop runs up the Lutley Valley, where coaly beds appear at a point 704 yards from Wassel Grove, as mentioned by Jukes.* In the course of a stream descending from Bog’s Farm, some 30 feet of pale-blue clay containing nodules of earthy limestone is seen. Coal, however, is not exposed. A persistent outcrop of clay runs from this point to the Stourbridge road near Witley Lodge, and this was examined by me, accompanied by Mr. Jew, 1 «Sketch of the Geology of the Birmingham District’ Proc. Geol. Assoc. vol. xv (1898) p. 368. 2 «The Silurian System’ 1839, pp. 54-57. 3 ‘The S. Staffs. Coalfield ? Mem. Geol. Sury. 2nd ed. ey pp. 28, 29. 4 J-inch Geological Survey map, Sheet LXII, 8. W. > * Silurian Sy stem’ Zoc, vit. 6 Tbid. 7 Proc. Geol. Assoc. vol. xv (1898) pp. 366, 368. 8 W.D. Conybeare & W. Phillips, “Geol, of England & Wales’ 1822, p. 417. 9 «The S. Staffs. Coalfield’ Mem. Geol. Sury. [Rec. School of Mines] Ist ed. (1858) p. 166. Vol. 69.] SERIES OF THE SOUTH STAFFORDSHIRE COALFIELD. 443 Manager of Witley Colliery, and a miner from that pit. The miner pointed out a spot where he had seen the coal proved. It was here 2 feet thick, ‘ with light-blue clay above and stiff blue clay below.’ Other places where the coal had been exposed were also indicated. Sprrorbis Limestone occurs in this clay near the colliery. From Witley Lodge the outcrop appears to run on the south side of the road into Halesowen. No exposure is now seen, but a Halesowen resident kindly pointed out to me a grass-grown ex- cavation above Queen Street, as the site of a former brickworks where the clay was burnt with coal from a 3-foot seam found in the clay-pit. There is also reason to believe that coal underlies the town of Halesowen from this point eastwards to the churchyard, since it has been proved in sewerage excavations in the streets of this locality. The churchyard is certainly situated on yellow (or blue) clays, in which indications of the presence of coal are found. South of the churchyard is a broad hollow which appears to have been once excavated somewhat extensively, but now shows only a clayey surface. This may well have been the site of the * coalworks ’ mentioned by Murchison. At this point the beds bend somewhat sharply south-eastwards, as the next exposure is in the bed of the River Stour, and clays are seen in ap adjoining lane to pass under pale-brown sandstones dipping south-eastwards. ‘his is the lowest point of the outcrop. A thin covering of clay occurs at ‘The Mount,’ and clay dips into the steep ascent of the Bromsgrove road below ‘The Grange.’ On the eastern side of Illey Brook, clay is found along the railway, and in the banks of the canal, where coaly traces have also been seen. ‘The beds are here rising at about 40° towards the Russell’s-Hall Fault, by which they appear to be cut off, as they occur in a different position in the ground beyond. East of The Leasowes, clays are well developed near the 600-foot contour-line, and beds above that level show fragments of coal in every rabbit-burrow and mole-heap. An outcrop of coal was mapped at this point by Jukes. Still farther east blue clays are exposed in Spies Lane, and shallow coal-mines were formerly worked at Moor Street. North of Mucklow Hill, pale-blue clays were formerly made into drain-pipes and tiles at the Bellevue Potteries, and it may, therefore, be inferred that the beds underlie the Glacial] drift which occurs upon the higher ground. A fault is visible immediately north of the last-named exposure, and no further indication of the presence of the beds is found between this point and the brickworks at Blackheath, where a 1-foot coal is seen, associated with bluish clay from which Dr. Walcot Gibson obtained Spirorbis Limestone exhibiting the characteristic fossil. It is, then, possible to trace pale-blue clays, which are associated with a.variable but persistent seam of coal and with earthy Spirorbis Limestone, from the western boundary-fault to the eastern borders: of the district. A definite horizon is thus established in Ad4 MR. H. KAY ON THE HALESOWEN sanpstone [ Oct. 1913, the Halesowen sequence, which is of great importance in regard to the classification of the Series. Other pale-blue clays, which are accompanied by ‘ coaly traces’ or impersistent thin coals and by Spirorbis Limestone, also occur, but these can readily be proved to he at a higher horizon. The name of the Halesowen Coal and Clays may be applied to these beds, the thickness of which varies from 10 to OU feet, being greatest within the town of Halesowen. ° (4) The Hasbury Group. Above the Halesowen Coal and Clays occurs a group of sand- stones which present special features of their own, owing to the presence of fragmentary foreign material. In the Lutley Valley, in a lane near the River Stour, and in Manor Lane, soft brown sandstones are seen, in which transported peaty material occurs. Above these are paler sandstones, speckled with indurated red marl and with coal-dust. Higher beds contain small pellets of the same materials, together with flakes of a peculiar white ash and tiny quartzite-pebbles. In the old quarries near Yew-I'ree Farm on Hasbury Hill, the blocks contain so much of the marl that they assume a dull purple hue, speckled with white, black, and yellow ; and sandstones similar to these occur in the lanes and stream-course near [ley Mill. A like succession of beds is found above the 1-foot coal in Ham Dingle, but in Hodge-Hill Dingle and Wassel-Grove Dingle the higher and redder beds are not exposed. SBeds similar to those of the two last-named localities are seen near the entrance to the Lappal Tunnel. Along a line from Ham Dingle to Lushbridge and thence to the northern parts of Hasbury Hill, the beds appear to be horizontal ; but south of a second line from Bog’s Farm through the southern portion of Hasbury Hill and the southern parts of the town of Halesowen, the beds dip from 15° to 20° south-south-eastwards, and disappear beneath a group of rocks which has still to be described. From their characteristic development near Hasbury, these beds are named the Hasbury Group. Their thickness varies from 120 to 150 feet. (5) The Illey Group. The remaining portion of the Halesowen Series forms the group separated by Prof. Lapworth under the title of the ‘Spzrorbis- Limestone Group.’ In consequence, however, of the discovery of that limestone at other horizons (p. 443), the group is now re-named the Illey Group, from the locality whence it was first described. The description given by Prof. Lapworth is as follows :-— «A thin series of red, grey, and oli®e-coloured shales and sandstones with a band of Spirorbis limestone and a few thin coaly beds.’ * 1 «Sketch of the Geology of the Birmingham District’ Prov. Geol. Assoe. vol, xv (1898) p. 366. ‘Vol. 69.] | SDRIES OF THE SOUTH STAFFORDSHIRE COALFIELD. 445 The red beds seen near Illey Mill have already been assigned to “the Hasbury Group (p. 444). Grey and olive-coloured shales and ‘sandstones follow these in ascending sequence in the Illey stream- courses. The ‘coaly beds’ have not been located by me, unless ‘these be identical with thin Coal-Measure binds recently exposed im a roadside-cutting at Lower Illey. In this exposure a sharp but low anticlinal fold is seen, and the binds are overlain by massive, ‘coarse, brown grits. Similar grits are found at Cooper’s Wood, farther east, where they overlie thin shaly sandstones fromewhich I obtained an impression of ? Pecopteris. In Kettle’s Wood the grits pass beneath bright-red marls belonging to the Keele Series. The true base of the Illey Group would appear to be certain grey, yellow, or blue clays and shales containing earthy Spirorbis Lime- -Stone, and seen immediately above Illey Mill. Clay-land extends from this point north-eastwards to near the Lappal Tunnel, and north-westwards towards The Grange. In the Stour Glen, west of the last-named point, and reaching as far west as Uffmoor Wood, pale-blue or yellow clay is strongly in evidence. In Uffmoor Wood a thin coal appears in the bed of -a stream, but this has not been found elsewhere. Still farther west the whole group disappears beneath the bright-red clays of the Keele Series. I have not traced the upper boundary of the group between the -Gypsy’s Tent and Lower Iley, the line laid down by Jukes, Ramsay, -and Hull having been accepted for the present. There remains to be noticed the remarkable exposure of bright- red sandstones found on Quarry Hill, south of Hasbury, and formerly mapped as Permian strata. These beds yield good ‘bailding-stone, and have been extensively quarried. They are red in external appearance only, since the blocks obtained from them are either red, variegated, or creamy brown. Bright-red marl is found in the rock-crevices, together with crystalline calcite. The ‘rock-partings are formed of dull-red marl mingled with coal-dust and white ash, or wholly of transported coaly material, in which case they appear as coal-seams a few inches thick. Rounded lumps of coal, of lignite, of red and yellow ochreous material likewise occur, together with rolled pith-casts of Calamites and other Coal- Measure fossils. At the base of the new quarry a lenticular bed of dark, tough, -ealeareous sandstone occurs. Quite recently a slab of this rock was raised, to the under side of which pale-blue clay was found ad- hering, and I was informed that clay of this kind underlies the whole quarry. It was stated that on the northern side it was but an inch or two thick, though it was 15 inches thick in the south- eastern corner. The beds dip at 15° to 20° south-south-eastwards. The slope of the hill, however, is greater still, with the result ‘that the clay reappears in the valley below, where it is widely -exposed, as already shown. 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"B21. g *NOISsa 000g NGMOSAIVA SHL dO MATA OILCONAG Vol. 69.| THE HALESOWEN SANDSTONE SERIES. 447° superior to, and conformable with, the argillaceous beds which form the base of the Illey Group. They appear, however, to have been accumulated under local conditions similar to those which prevailed more generally during the formation of the Hasbury Group: namely, the occasional distribution in |the sediment of material. derived from the denudation of red Coal-Measure clays and of coals. The bright-red coloration is evidently a subsequent feature, due to staining from above. * V. Tue Disrosirion oF tHE Bens. (1) Folding. At the southern end of the South Staffordshire Coalfield a deep syncline appears, ranging about south-south-eastwards through Halesowen and Illey, while there is a tendency to anticlinal con- ditions observable in the neighbourhood of the eastern and western boundary-faults. The synclinal structure is indicated by the following observations :— From Furnace Hill to Lower Iley the rocks dip persistently south-eastwards, and the Thick Coal at Witley dips towards Halesowen at 1 in 13." From Coombeswood to Cooper’s Wood a high south-westward dip prevails, which is as much as 30° on Mucklow Hill, while the Thick Coal dips westwards at 1.in 6.° The tendency to anticlinal conditions between the line last indicated and the eastern boundary-fault was noted by Jukes.* It is also apparent from the low east-south-eastward dip of the strata at the Bellevue Potteries and thence southwards to Moor Street. The beds of the Halesowen Coal and Clays, exposed in the Leasowes Hstate at over 600 feet O.D., are reached only in shallow mines on the !' wer ground at Moor Street. The wester: anticline does not appear to have been recorded hitherto, but is apparent from the fact that, whereas the highest members of the Hasbury Group are found near the 500-foot con- tour-line at Ham Dingle and at Hasbury, lower members of the same group appear 100 feet higher on Hodge Hill. The elevation, however, is slight in comparison with the breadth, and the western limb of the anticline is cut off by the boundary-fault of the coal- field. An important flexure traverses the district from near Wassel Grove to Hasbury and the southern parts of Halesowen (p. 444). This feature does not appear to have been adequately recoguized by previous observers, and its neglect has resulted, in one instance at least, in the fruitless endeavour to reach the Halesowen Coal-seam by shallow mining in the Stour Glen near St. Margaret’s Hill. Jukes appears to have regarded the ‘ little coals’ of Uttmoor Wood 1 W. Mathews, ‘The Halesowen District of the South Staffordshire Coalfield ’” Proc. Birm. Phil. Soc. vol. v (1887) p. 322. 2 Td. ibid. : * ) Amygdaloidal Sediments. (c) Metamorphism of the Sediments. Wo" Letenuil ie] Sgeigienaishs Géahceccapanonbernocoodeelnpedoseetooouensnoadée 480 Wales Comelustonsy Mies cecclsanestiescolecsecieneseeestisevep sta docs ae’ of 481 I. Iyrropvctron. Tur earliest description of the volcanic rocks of Lower Old Red Sandstone age, which are so admirably exposed on the coast of Forfarshire, we owe to the Rev. John Fleming,’ whose observations were in a remarkable degree unprejudiced by the theories prevalent at the time when he wrote. A fuller account of the rocks as they appear in the field is given by Sir Archibald Geikie in his ‘ Ancient Volcanoes of Great Britain ;’° but no attempt has been made, up to the present, to describe the rocks of this locality as they appear under the micro- scope, although similar rocks-in adjoining areas* have been so dealt with. The Geological Survey 1-inch maps* clearly indicate the occurrence of a great anticline, a continuation of the Ochil Axis, which runs in a general east-north-easterly direction, passing out to sea near Montrose,’ where exposures of the oldest lavas may be seen. On following the coast southwards from Montrose, one meets with higher beds in the volcanic series; these extend as far as the Lunan-Bay sands, beyond which a newer and higher series of lavas _ 1*On the Mineralogy of the Redhead in Angus-shire’? Mem, Wern. Nat. Hist. Soe. vol. ii, pt. 2 (1815-18) p. 339. * Vol. i (1897) pp. 299-301. 3 «The Geology of Central & Western Fife & Kinross’ Mem. Geol. Surv. 1900 ; ‘The Geology of Eastern Fife’ Mem. Geol. Surv. 1902; R. Campbell, ‘Geology of S.E. Kincardineshire’ Geol. Mag. dec. 5, vol. viii (1911) p. 69. 4 Forfar, Sheet 57; Arbroath, Sheet 49. _ Sir Archibald Geikie, ‘ Ancient Voleanoes of Great Britain’ vol. i (1897) p. 299, Fig. 1.—Geological map of the coast, from Montrose to Fishtown of Usan. MONTROSE ™ fo) MONTRO SENESS LIGHTHOUSE ) FISHTOWNx or USAN | Scale of Furlongs 2 3 a 1 ; Olivine-basall with olivine-phenocrysts [=| Lower Old Red Sandstone sediments, including true }___fey ‘conglomerates interbedded with lavas. Porphyrite-dy kes. Vol. 69.| HE VOLCANIC ROCKS OF THE FORFARSHIRE COAST. 461 forms the promontory that juts out eastwards on the south side of the Bay. These lavas are succeeded by sandstones, all dipping consistently south-eastwards. Broadly speaking, therefore, the field-relaticns of these rocks are quite simple. When, however, we descend to detail, the petrological similarity of the different lava-flows, their lenticular character, as also the lenticular character of the conglomerates and sandstones which are found among them, make it very difficult to ascertain the precise effects of the faults that frequently occur, and con- sequently to obtain a correct idea as to the order in which the’ lava- flows succeeded one another. The excellence and accessibility of the cliff-sections between the Red Head and Lunan Bay has led to an attempt to investigate their structure in greater detail than has been found possible in dealing with the coast between Lunan Bay and Montrose, II. Fre,p-Renarions oF tHE Rocks. (a) Montrose to Lunan Bay. About a quarter of a mile south-west of Montroseness Lighthouse, a fault occurs, separating two types of lava which can be dis- tinguished one from the other quite easily. North of the fault, and extending round the coast as far as Ferryden, the voleanic rocks nearly all contain numerous lath- shaped felspar crystals, which are particularly obvious on weathered surfaces. These rocks’ may be termed enstatite-olivine- basalts. In colour they vary considerably, black or grey-black predominating, though some are greenish, purple, or brownish-red. The lavas are individually of no great thickness, rarely exceeding 10 or 12 feet, and are bedded in a very irregular manner. At the base of each sheet occurs a few inches of compact, almost flinty rock, which is moulded upon the irregular surface of the rock beneath. Above, the rock becomes obviously coarser in grain, and this passes upwards into very slaggy purplish lava, usually full of green amygdales, and much weathered. The amygdaloidal lava is generally much fissured, the fissures and larger cavities being filled with hard, fine-grained, greenish or brownish-red sandstone, which often penetrates into the more compact lava below, where the fissures become less numerous and thin out. The sediment frequently expands into sheets, usually not more than a few feet across, at the surface of the lava. The regular recurrence of these characters, which are typical of the lavas of Lower Old Red Sandstone age,” suggests the gradual accumulation of sheets of rock solidifymg from the molten state under conditions that allowed of the contemporaneous deposition ! Petrographical descriptions of these and other rocks named in this section are given later in § III, pp. 472-75; § LV, pp. 475-77. 2 Sir Archibald Geikie, ‘ Ancient Volcanoes of Great Britain’ vol. i (1897) pp. 263-347. 462 DR. A. JOWETT ON THE [Oct. 1913, of fine sediment, probably in water of no great depth, as the sediments are generally current-bedded. Near the fault mentioned above (p, 461), a highly-contorted layer of sediment, coarser than usual, was found interbedded with the lava. This is composed almost entirely of voleanic débris, and is probably one of the finer-grained beds associated with the volcanic conglomerates. South of the fault, the felspar-phenocrysts so characteristic of the lavas met with on the north and west are no longer found—the new rocks being generally fine-grained, with obvious red phenocrysts representing pseudomorphs after olivine. These rocks are olivine- basalts. This type of lava extends southwards continuously for a mile and a quarter, as far as Fishtown of Usan. Up to this point the rocks are exposed only between the tidal limits, the low cliffs being here grassed over. Excellent horizontal sections, however, are exposed ; and, where the harder rocks have resisted the action of the waves, crags 10 or 12 feet high provide good vertical sections. A few faults are traceable, but I could find no evidence that their throw is considerable. The upper portions of the lavas are amygdaloidal, much fissured, and covered by a variable thickness of slagegy fragments, so that, with the sediment deposited in the crevices, they resemble con- elomerates in appearance. In some cases, the rock-fragments are rounded, forming true conglomerates, often of no great thickness, intercalated in the series. Sometimes the compact base of a lava- stream rests directly upon amygdaloidal or even compact lava with sandstone-filled fissures, without any intervening ‘ conglomerate,’ probably indicating that the loose material usually present has been removed and deposited a little distance away as a true conglomerate. The frequent redness of such slaggy and conglomeratic beds has been attributed by Sir Archibald Geikie* to oxidation during the lapse of time between two successive outflows of lava. The compact lavas vary much in colour, the fresh rocks being almost black, but passing, with varying degrees of weathering, through shades of grey, purple, brown, and red to a lilac tint. A quarter of a mile south-east of ‘Mains of Usan, much- weathered lavas are clearly overlain by a massive conglomerate full of well-rounded boulders measuring up to 3 feet in diameter. At the base of the conglomerate occurs a non-persistent layer of red sandstone, sometimes 18 inches thick. The matrix of the conglomerate consists of a coarse purplish sediment, which, when microscopically examined, is found to be composed almost entirely of small fragments of different kinds of voleanic rock. The’ boulders in the conglomerate, though all of volcanic origin, are not all of the same type, some exhibiting porphyritic felspars. At the surface of the conglomerate is a layer of 12 to 18 inches 1 « Ancient Volcanoes of Great Britain’ vol. i (1897) p. 801. . Vol. 69.] VOLCANIC ROCKS OF THE FORFARSHIRE COAST. 463 of sediment, similar to the matrix of the conglomerate. The conglomerate dips southwards under an escarpment of compact lava, 10 to 15 feet high. A number of spheroidal masses of voleanic rock about 2 feet in diameter, which exhibit concentric amygdales where broken across, occur in the lower portion of this lava. They are embedded in compact lava, and are the best examples of ‘pillows’ that I have observed along this coast, although a rude pillow-structure is not uncommon. ‘The upper portton of the lava becomes more amygdaloidal, though lenticular amyg- daloidal patches occur within the more compact mass, and towards the top it is of a brick-red colour and much intersected by fissures filled with green sandstone. A somewhat remarkable exposure of conglomerate occurs about half a mile north-east of Fishtown Fig. 2.—Plan of the junc- of Usan. The conglomerate rests tion between conglomerate on an irregular surface of volcanic and lava, north-east of rock, apparently filling in a network Ishtown of Usan. of valleys. The junction between the two is sometimes vertical and quite irregular in plan, though not faulted, one example appearing as shown in the appended fig. 2. All the boulders examined in this conglomerate were volcanic rocks of a type characterized by felspar- phenccrysts. The cliffs commence at Fishtown of Usan, and continue almost with- out a break as far the sands of Lunan Bay. Immediately east of Fishtown a great wall of rock rises about 50 feet above the shore, and is separated by a narrow gap from the cliff. It consists partly of a dyke* and partly of the lavas into which the dyke was intruded. The dyke is about 63 feet wide, and is a brownish-red rock with fairly large felspar-phenocrysts and some green amygdales. This rock is a porphyrite, and is easily distinguished by its felspars from the lavas into which it is intruded, as also by the absence of the sandstone-filled fissures and clinker-beds which are so charac- teristic of the latter. West of the harbour of Fishtown of Usan, the olivine-basalts are succeeded by a type of volcanic rock which is characterized by large plagioclase-phenocrysts, as also abundant red and green amygdales. This new type of lava, an enstatite-basalt, is a famous hunting-ground for agates and other secondary minerals,* and the upper portion of each sheet is seamed by fissures ‘filled with pale- . 9 Caen e neo fe, fo} fo) Oe eee rie eo fo) fo) 1 Geol. Sury. l-inch map, Sheet 57. 2 M. F. Heddle, ‘Mineralogy of Scotland’ 1901, vol. i, pp. 75-76, 106, 151, & vol. ii, pp. 140, 146. 464 DR. A. JOWETT ON THE [Oct. 1913, green sandstone. As the strike is here parallel to the coastline, not many different lava-flows are exposed. At the Rock of St. Skae occurs another dyke’ of porphyrite, which is intruded in close proximity to an important fault. The dyke and silicified fault-breccia together form a vertical wall of rock i wive-plrenocis'sts ==--—----=-—— BODDIN POINT te-dykes----- Porphyvri Upper Ola Red Sandstone.-------—-~--=~-—----~--— fy Olivine-basalt with oliz Enstatite-basalt,---=---------------~--- and pyroxene (7 Fig. 8.—Geological map of the coast, from near Pishtown of Usan to the Lunan-Bay sands. Scale of Furlongs rising from the beach to a height of over 100 feet, and projecting from the cliff southwards across a small bay which is flanked on each side by steep cliffs. The ‘Rock’ has been tunnelled by the * Geol. Surv. l-inch map, Sheet 57. A Vol. 69.] VOLCANIC ROCKS OF THE FORFARSHIRE COAST, 465 waves a little below high-water mark, where it is about 30 feet wide. The dyke is about 16 feet wide. The eastern side of the ‘Rock’ is horizontally slickensided over a large area, and hori- zontal slickensides may also be seen in a cleft along the ridge running in a direction north 6° west. In the cliff on the east, and cutting across the ‘Rock’ just behind the Chapel, another fault occurs, which is almost exactly at right angles to this (north 82° east), apparently displacing it, and is slickensided almost vertically, throwing the rocks on its southern side some little distance westwards horizontally. About two-thirds of the way across the little bay east of the ‘ Rock’ more fault-breccia may be seen at about high-water mark, and this fault is exactly parallel to the trend of the ‘ Rock’ (north 6° west). The difference in character of the vein-stuff* parallel to these two sets of faults also furnishes evidence that the east-and-west fault is of later date than those running north and south. The dyke is displaced by the east-and-west fault movement, and is brecciated by both faults. Moreover, in a cliff-section in the gully north of the Chapel of St. Skae, the dyke appears flanked on each side by lava, the main fault-movement (indicated by breccia) having occurred in the lava. It is evident, therefore, that the intrusion took place prior to the initiation of the older north-and-south faults. From the Rock of St. Skae to Boddin village, the lavas are olivine-basalts, which contain plagioclase-phenocrysts and monoclinic as well as rhombic pyroxenes. Excellent sections of amygdaloidal lavas with sandstone-filled fissures may be seen in the cliffs. On the shore in Boddin Harbour near high-water mark, a fault which throws calcareous Upper Old Red Sandstone against the volcanic rocks is well displayed in horizontal section. The excellent vertical section of the same fault where it emerges north-west of Boddin Point, and the Upper Old Red Sandstone itself, have been well described by Dr. G. Hickling. The surface of the sandstone is slickensided, the striations inclining at 10° from the vertical, and therefore the total effect of the fault would be, not only to throw the sandstone down southwards, but also to move it westwards to a slight extent. Parallel slip-planes occur in the sandstone for some distance south-east of the main fault; and, even at the extremity of the headland 300 yards away, there is a well- marked fault which trends exactly in the same direction. Some 50 yards west of the corner of the bay where the large fault emerges, a porphyrite-dyke is intruded in the lavas in the cliff and on the shore. It trends north 8° west, thus being practically parallel to the St. Skae dyke, which it closely resembles; although the lavas are not faulted alongside it asin the latter case. ‘The dyke varies in width from 3 to 6 feet, and is markedly finer in grain for about 3 inches from each of its boundary-planes. l See below, p. 480. 2 «The Old Red Sandstone of Forfarshire, Upper & Lower’ Geol. Mag. dec. 5, vol. v (1908) p. 404. 466 DR. A. JOWETT ON THE [Oct. 1913, About 15 yards from the cliff, the dyke is cut off abruptly against the Upper Old Red Sandstone by the main fault, which is con- tinued along the shore. A smaller fault in the lava, parallel to the main fault, and nearer to the cliff, throws the dyke 18 inches horizontally westwards. This dyke is unquestionably of Lower Old Red Sandstone age. Some 50 or 60 yards west of it another important fault occurs, which causes a small inlet and trends north 57° east—almost parallel to the main fault (north 62° east). We see, then, that a number of faults having the same general trend, and evidently the result of closely-related earth-moyements —probably all throwing down south-south-eastwards, and effecting a shght horizontal westward movement of the rocks on their southern sides—occur between the Rock of St. Skae and the bay west of Boddin Point. Now, the general trend of the coastline, from Fishtown of Usan to the Lunan-Bay sands, is closely parallel to the general trend of this system of faults, and it seems very probable that the similarity is more than a mere coincidence. The significance of these facts will be more apparent when we come to consider the system of faults parallel to the line of cliffs on the south side of Lunan Bay. To return to the voleanic rocks west of Boddin Point. Nearly all are very much weathered, some too much so for proper deter- mination. The one against which the Upper Old Red Sandstone is thrown is a much-weathered amygdaloidal rock with feispar- phenocrysts, and is probably an olivine-basalt. On the northern side of the fault, in the small inlet 100 yards farther west, an olivine-basalt without felspar-phenocrysts oceurs, but this is immediately overlain by a type containing obvious felspars. There is a remarkable development of the sandstone-filled fissures and clinker-beds among all the lavas in these cliffs. Usually, well nigh half of the total thickness of each lava-sheet is composed of such material ; but, sometimes, the lava is so completely penetrated by veins of sandstone that very little unbroken compact volcanic rock remains. The total thickness of a complete sheet in this neigh- bourhood is only about 15 feet on the average. Farther west much thicker sheets occur, especially near the outlet of Dunninald Den. Here an important north-and-south fault throws. down westwards a thick sheet of enstatite-basalt, which appears to extend without a break from high-water mark nearly to the top of the cliffs. A rock very similar to this occurs on the eastern side of the ‘Den, about a third of the way up the cliff, where it rests upon olivine-basalt. I could find no trace of the ‘dyke’ marked on the Geological Survey 1-inch map, but a peculiar silicified breccia occupies the position of what I take to be the fault mentioned above. The cliffs (Rickle Craig) from south of Dunninald Den to the Lunan-Bay sands are high and rugged, exhibiting some fine ex- amples of the effects of marine erosion on rocks of this character. a Vol. 69.] VOLCANIC ROCKS OF THE FORFARSHIRE COAST. 467 All the accessible rocks appear to be olivine-basalts, the type with felspar-phenocrysts disappearing westwards. The outcrop of the lavas terminates as a cliff, against which Glacial deposits, beaches above the present level, and blown sand are banked up. I could find no evidence of the relations between the lavas and any other solid rocks in the vicinity. (6) Lunan Bay to the Red Head. From Lunan Bay to the Red Head, all the voleanic rocks are olivine-basalts, between which, with one exception, it is not easy to distinguish in the field. The exceptional type has obvious _felspar-phenoerysts, and is exposed in the lower part of the cliff for about 300 yards west of Ethie Haven. No dykes have been found in this series. There seems to be no doubt that a considerable thickness of sandstone—Dr. Hickling’s Cairnconnan Series \—is intercalated between the lavas on the south and those on the north of Lunan Bay. For some distance west of Lunan Bay the solid rocks are buried under superficial deposits, but in the south-western corner of the bay several outcrops of sandstone of a different kind occur in the cliff and on the beach. Near the base of the cliffs at Bird’s Knap, immediately south of the mouth of Keilor Burn, is an exposure, almost obscured by vegetation, of red and yellow sandstone resting upon a breccia containing angular red sandstone. Black Rock, which emerges from the sand on the shore about 100 yards north-east of this exposure, is a mass of breccia, composed almost entirely of angular red sandstone, but containing a few small rounded boulders of volcanic rock. South-eastwards, the sand on the shore gives place to a bare rock-surface consisting of much-weathered volcanic rock, which rises here and there into stacks of harder but still much- weathered basalt. No sandstone appears, except the usual sedi- ment intercalated with the lavas. South-east of Bird’s Knap the cliff rises, but continues to be grassed over until it bends sharply eastwards, where it 1s seen to consist entirely of basalt. The lower part of the cliff is well-slickensided for some distance, and clearly indicates the presence of a fault; this appears in a projection of the cliff farther west, and eastwards runs across the beach. The fault has a trend about 15° north of east, hades northwards at an angle of 19°, and the slickensides incline west- wards at an angle of 20° from the vertical. There is a good deal of smashing parallel to this fault, which is marked by parallel veins of calcite wherever a section occurs in a direction at right angles to the cliff. It is quite clear that the trend of the cliff is largely dependent upon the direction of this system of faults. About 200 yards east of the south-western corner of Lunan Bay, a mass of silicified fault-breccia (3 feet wide) stands out like a ' Geol. Mag. dec. 5, vol. y (1908) p. 4C0. 468 DR. A. JOWETT ON THE [Oct. 1913, dyke from the cliff and above the beach. It marks the position of a fault which runs north 28° west, and hades westwards at an angle of 16°, This fault is obviously older than the east-and- west fault-system described above, for its fault-breccia is broken Fig. 4.—Geological map of the coast, from the Lunan-Bay sands to the Red Head. LL (UW IN AINA IE Scale of Furlongs I 2 2 =) ——— as! Line oF Section, 75) Gee / ~~ south Mains North Mains SF ear ) ae 7 é Sp RED HEAD Olivine-basait with BIG S10 1GSC PIE OCH) Si) ae eeeeereea| | and olivine im gromudimass. Olivine-basalt with oliviive-phenocrysts, —-——-——---—---— Olivine-basalt with glonveroporphyritic aggregates of\____ olivine, augite, and labradorite. y) Lower Old Red Sandstone sediments, including i eee es conglomerates interbedded with lavas. Upper Old Red Sgaidstone= ee ee eee across by a member of the latter, and the portion of fault-breccia on the northern side is thrown westwards a distance of 6 feet. On the shore 300 yards west of Ethie Haven, and about half way between high- and low-water marks, occur two large detached masses of red and yellow mottled sandstone resting on a sandstone- breccia. Some portions of the sandstone exhibit a beautiful poiki- litic structure when broken, owing to the uniform crystallization a Vol. 69.] VOLCANIC ROCKS OF THE FORFARSHIRE COAST. 469 of the calcite-matrix over patches measuring a quarter to half an inch in diameter. The beach is covered with large boulders set close together, but its foundation appears to consist of volcanic rock, and some large stacks of basalt 7m sitw stand out at low-water mark between these masses of sandstone and the sea. Some 50 yards farther north-east, an escarpment 150 yards long may be seen at exceptionally low tide. Its edge is almost horizontal, and strikes north-west and south-east. The rock consists of a+ well- bedded sandstone-breccia, dips north-eastwards at about 5°, and appears to rest upon a denuded surface of volcanic rock. The close lithological resemblance between these sandstones and the Upper Old Red Sandstone of Boddin Point, coupled with (as Dr. Hickling informs me) their dissimilarity to any of the sand- stones of the Cairnconnan Series, favours the opinion that they are of Upper Old Red Sandstone age, a probability which is strengthened by the marked unconformity that appears to exist between them and the lavas upon which they rest. Further, it seems very likely that the mass of Upper Old Red Sandstone, which rises a little above high-water mark at Boddin, skirts the coast not far below low-water mark from Fishtown of Usan to the Lunan-Water estuary, being thrown down by the faults that run parallel to the coastline; also, that it continues under Lunan Bay and much of the drift-covered area on the west, reappearing in the cliff and along the shore south of Lunan Bay in close relation with another series of faults, which are cognate with those on the north side of the bay, and have a similar effect in determining the line of cliffs. It is significant that such an area of Upper Old Red Sandstone coincides remarkably in position with the Upper Old Red Sandstone which emerges here and there through the superficial deposits north of Montrose, and is possibly continuous beneath them. ‘The same kind of feature is again repeated in the occurrence of Upper Old Red Sandstone at Seaton Bay, north-east of Arbroath. An attempt has been made to represent, by means of the accom- panying ideal section (fig. 5, p. 470), every important feature along the coast from the south-western corner of Lunan Bay to the Red Head. ‘The rocks are so admirably exposed, that most of what is set down may be directly observed, little being the product of mere inference. This is more particularly the case with the part of the coastline trending from north to south outside Lunan Bay. From what has already been said, it will be understood that the base of the series of lavas south of Lunan Bay is not exposed. How far they extend northwards under the cover of Upper Old Red Sandstone is merely a matter of conjecture. Inland they thin out, as represented on the Geological Survey map, towards the south- west. It is probable that they thicken north-eastwards, and ulti- mately unite with the lavas north of Lunan Bay, the intervening Cairnconnan Sandstones thinning out in the same direction. The lavas succeed each other regularly, with the usual admixture of sediment in the upper portion of each shect, until at Ethie Haven, “erooaaq-ouoqspues pUv oUOJspULS pat pofzJouL + ouojspueg pay plo weddy = x ‘O}LOpV.AGL] pur “oz1snv “ULAto ») . — SQ a SaTpernaq- = lo . syronrormootn [wooT =2 -attoqspurg jo Bee EA GIe orqtdydiodo.cautols UT AMEE eMIaN (Oy 2 | auospurg “SSLULpPUNOLS o1[} 54 OFVLOULO[SWOD BULF JO SpUB TIM “oper[s pary == p tL part UL AULATTO puv SysAOOUaTA-osvpoorsyrd TILA qpesuq-autAl[Q = ¥ pew “OUBDTOA T[B Apwatl s[VitozLOI + szuotIIpas woul = 2 LO “yUNUIpos auyE Aq pozuotttod ALT ASSL[S Jo sassvyy = 4 aio) “OLUBITOA TTB ATWO S[VLLeyRUU + ayRAaUTO[SUOD asivoD = q TIMO'T ‘s}sAtooUoyd-aULAl[O ILM qpRsUq-auraT[G = f’ peel ‘auoyspuLs {3.5 puB payy = v ooor 006 00g 004 009 «0S cob oof odz oor C0) 99, JO ayvag f “mM WOAeH IIIA ‘a oO st! 72 Tie Z Se aE : ee = ae WAT yea H epee ‘aS'S/ ANN 2 OTe=[ ST Eras BirKekerelera SW Alu vi ‘a NN yoo] 4a AyI2HS 30y PeoH pew “MASS ‘hing unungy £0 wautoa ucajsam-yynos ay) pun UIAMFT a2rYieT 07 pHazT pay oyg wo.f ysn0o ay) Luopy woryoss oynununhnrg —'e ‘OL ae a Vol. 69.| THE VOLCANIC ROCKS OF THE FORFARSHIRE COAST. 471 they dip beneath a thick mass of very red conglomerate, ‘This conglomerate rests upon more than one type of basalt, and it doubt- less marks a stage when the eruptions were much less frequent and considerable erosion of the lavas took place. Its materials are very much weathered. At least two very fine-grained basalts are included within the conglomerate, one of which is weil displayed immediately east of Ethie Haven at high-water mark. It forms an extremely-irregular lenticular sheet, and, where it thins out, appears to split into two or three layers which dovetail into the conglomerate. ‘The upper surface of the conglomerate is irregular, sometimes ‘dipping steeply under the lava which rests upon it. The lava is fine-grained, and breaks into thin plates near the junction. In general appearance, the basalts met with above this horizon closely resemble the lavas already described.’ Very rugged coast scenery results from the action of the waves in tunnelling through ‘the soft amygdaloidal lava and conglomerate and preserving the more compact lavas, although sometimes a conglomerate is more resistant than the lavas. On the eastern side of the promontory, where the coastline leaves Lunan Bay and turns abruptly southwards, is a series of amygda- lloidal lavas having at its base a red conglomerate. Immediately above the conglomerate occurs a mass of big rounded blocks of scoria- ceous lava, embedded partly in lava of a similar type and partly in finer conglomerate. This is another example of ‘ pillow ’-lava. Excessive weathering of the compact basalts seems to show itself in the development of calcite in felspar, pyroxene, and olivine alike, giving to the whole rock a pale coloration, almost white by contrast with the comparatively unaltered rock. Such rocks are generally found in association with red ‘conglomerates.’ Fine examples may be observed in the neighbourhood of the ‘ Spectacle.’ South of Rock Skelly, excellent sections occur, showing a true conglomerate, with large boulders of volcanic rock, resting upon a very irregular denuded surface of the underlying lavas. Along the shore, the waves are cutting away the softer conglomerate, and laying bare the hard stacks of lava buried beneath it. At Rock Skelly, a thick sheet of hard lava fills in and covers the hhollows and mounds which form the surface of the conglomerate. The lower portion of this lava is very platy, the divisional planes ‘preserving a rough parallelism with the irregular surface of the conglomerate, which is hardened at the contact and overhangs the softer conglomerate beneath it in the cliff. The main mass of ‘the lava exhibits a rude columnar jointing, and although upwards of 30 feet may be seen in some sections, its original upper surface -does not appear. ‘There is little doubt, however, that the conditions which produced the conglomerate beneath it continued after its extrusion, and led to its partial removal by denudation before it was protected by further sedimentation. This is more likely because 1 Ante, pp. 461, 462. Morn Gs 8. No.-275. 21 472 DR. A. JOWDTT ON THE [Oct. 1913,, another rock, practically identical with it petrographically, and! occupying a similar stratigraphical position (that is, with the same conglomerate below and above it), crops out at the foot of the cliff farther south. The upper portion of this lava is amygdaloidal. The conglomerate preserves its hummocky surface in a very striking manner when it is buried in the overlying red sandstones,. which first appear at the top of the cliff immediately south of Rock Skelly. The sandstone is current-bedded around the mounds, but. quite evenly bedded above them, dipping away steadily southwards. The conglomerate itself is by no means uniform in texture, sometimes including fairly thick bands of red sandstone and of finer conglomerate: these, however, were often partly removed by the stronger currents which brought the larger boulders that make up.. the coarser part of the deposit. On the whole, the conglomerate appears to thin out northwards. Farther south, higher beds of red sandstone, shale, and con-- glomerate attain a great thickness in the cliffs, and all appear to. contain more or less volcanic débris. The beds of conglomerate increase in thickness, and their boulders increase in size towards the south, consisting almost entirely of voleanic rocks with occasional angular and subangular pieces of red sandstone. They are covered by thick beds of sandstone, which, higher in the series, include pebble-beds of an entirely different character, containing a pre- ponderance of well-rounded pebbles of quartzite, in addition to those of volcanic origin. Ill. Parrograray or tHE Ieneous Rocks. (a) lavas. (1) Petrographical types.—The distribution of the various types of lava is indicated on the sketch-maps (figs. 1, 3, & 4, pp. 460, 464, & 468). The enstatite-basalt is the only type from which olivine is absent, and, although it occurs for a considerable distance along the coast north of Lunan Bay, it constitutes but a small fraction of the lavas between Montrose and the Red Head. The olivine-basalts may be divided into two main groups, according as olivine occurs iu the form of phenocrysts, or is entirely restricted to the ground-mass. The former group is the more abundant, the latter including two varieties only: one with enstatite and plagioclase-phenocrysts (near Montrose), and one with plagioclase-phenocrysts only (near Ethie Haven). The most abundant variety in the former group has, broadly speaking, no phenocrysts except olivine, augite occurring in the ground-mass with felspar and iron-oxides; although in other varieties phenocrysts of (1) labradorite, (2) labradorite and augite, and (3) labradorite and rhombic pyroxene occur, in addition to the olivine-phenocrysts. One variety is full of glomeroporphyritic aggregates of olivine, augite, and labradorite (South Mains and Rock Skelly). No A Vol. 69.] VOLCANIC ROCKS OF THE FORFARSHIRE COAST. 473 rhombic pyroxene has been found in the lavas from Lunan Bay to the Red Head. (2) Order of eruption of the different types.—The stratigraphical succession of these varieties of lava appears to be as follows :— Latest eruptions (Red Head). Glomeroporphyritic olivine-basalt, less* basic than usual. (Slight unconformity.) Normal type of olivine-basalt, with phenocrysts of olivine only. (Shght unconformity.) Olivine-basalt, with phenocrysts of basic labradorite, and olivine confined to the ground-mass. Normal oliyine-basalt. (Base not seen.) . . TS Cairnconnan Series = of sandstones, bee Normal olivine-basalt. (Upper limit not seen.) Olivine-basalt, with phenocrysts of olivine, labradorite, and sometimes pyroxene. Enstatite-basalt, with phenocrysts of enstatite and basic labradorite. Olivine-basalt, with phenocrysts of olivine, labradorite, and pyroxene. Olivine-basalt, with phenocrysts of olivine and labradorite. Normal olivine-basalt. Hnstatite-basalt. Normal olivine-basalt. Olivine-enstatite-basalt, with phenocrysts of labradorite and enstatite, and olivine in the ground-inass. Earliest eruptions exposed (near Montrose). (3) Minerals present.—Felspar. The phenocrysts vary in composition from medium to basic labradorite. They are often quite fresh, exhibiting twinning of albite, Carlsbad, and pericline types. In some rocks, however, they are so much altered as to be incapable of determination. The commonest alteration-products are calcite and chlorite. Glass inclusions are common. The felspar-crystals of the ground-mass are frequently twinned, and prove to be labradorite of a less basic type than the phenocrysts in the same rock. 212 A474 DR. A. JOWETT ON THE (Oct. 1913, A peculiar type of felspar giving rhomboidal sections is found sporadically in many of the olivine-basalts. The crystals are rarely twinned. Olivine.—No fresh olivine has been found in any of these rocks. The commonest type of pseudomorph has a green ser- pentinous interior bordered by reddish-brown material, which also traverses the irregular cracks in the crystal. ‘This type passes gradually into a type entirely serpentinous on the one hand, and into a type devoid of green decomposition-products on the other. Crystals of the latter type are sometimes pleochroic and fibrous, resembling iddingsite. The green alteration-product is fre- quently fibrous, pleochroic, and strongly birefringent. In the more altered rocks it becomes colourless, but still exhibits strong double refraction, When most altered, the olivine is represented by pseudomorphs in rhombohedral carbonates and iron-oxides. In many of the rocks in which phenocrysts of olivine are present, small crystals also occur in the ground-mass. In some types, the olivine, although one of the first minerals to crystallize, never attains a greater size than that of the other minerals of the ground-mass. Monoclinie pyroxene.—The augite is pale green to colourless in thin section. The larger crystals are commonly twinned, but the mineral is most abundant in the ground-mass in a granular form, though occurring (rarely) as small prisms. Rhombohedral carbonates are the usual decomposition-products, though sometimes the augite is replaced by chloritic material. Rhombic pyroxene.—A very fresh, non-pleochroic, rhombie pyroxene occurs in some of the olivine-basalts near Montrose. It is sometimes intergrown with augite; but, more generally, each erystal of enstutite has a border of granular augite. Green faintly-pleochroic bastite is the most characteristic alteration-product, but further alteration produces rhombohedral carbonates and even secondary quartz. In the much-altered rocks it is not always possible to distinguish satisfactorily between the rhombic and the monoclinic pyroxenes. Rhombic pyroxene has not been found as a constituent of the ground-mass of any of the rocks. A glomeroporphyritic aggregate of bastite, enclosing olivine and basic plagioclase, was found in a section of one of the lavas west of Boddin Point. Magnetite occurs as well-formed octahedra in the ground-mass of some of the rocks. In the granular form, it is always abundant in the interstitial glass). Hematite and limonite are also abundant. A patite-needles occur in all the rocks. Biotite is fairly abundant in a few rocks. It occurs as clear crystals, one giving the characteristic optical figure, and as opaque rods and fibres. A Vol. 69.] VOLCANIC ROCKS OF THE FORFARSHIRE COAST. ATS The minerals that fill the amygdaloidal cavities have beer described by Heddle.’ The commonest are calcite, chalcedony, and chloritic minerals (celad onite and saponite). (4) Structures.—The great majority of the rocks consist of phenocrysts set in a ground-mass of felspar-laths—generally with some augite—and interstitial glass, which is sometimes more abundant than the minute crystals of the ground-mass. * The ground-mass is holocrystalline in some of the rocks. Well-marked flow-structure is usually indicated by the arrange- ment of the felspar-laths and by the elongation of the amygdaloidal cavities. : Microporphyritic structure is frequently seen, and one rock-type is characterized by an abundance of glomeroporphyritic aggregates, Glomeroporphyritic structure is occasionally met with throughout. Some very fine-grained rocks occur, in which the phenocrysts are similar in size to the minerals in the ground-mass of the usual type. One example is extensively developed inland at Compass Hill, Friockheim, and Wuddy Law. (o) Dykes. The only evidence of intrusion among the rocks in this area is furnished by a series of dykes of Lower Old Red Sandstone age north of Lunan Bay. All these rocks are much altered, but appear to be very similar. They may be called porphyrites. The one that is least altered occurs near Fishtown of Usan. Its felspar-phenocrysts are probably andesine, and are full of glass- inclusions and iron-oxides. Some doubtful pseudomorphs which occur may have been pyroxene, but now consist of silica. The ground-mass includes some stout plagioclase-crystals as well as felspar-laths, magnetite, haematite, and dusty interstitial glass. Some small patches consist of hematite enclosing the felspars poikilitically. The numerous amygdales contain chalcedony, quartz, and chlorite. The other rocks are finer in texture, but possess similar minerals and structures. In addition, they contain a yellowish- white opaque mineral which is apparently leucoxene after ilmenite. The supposed pyroxenes are few and small in proportion to the felspar, and there is no suggestion of olivine having been present, so that these rocks are much less basic than the lavas. TV. Tue Sepiments AssoclaTeD WITH THE LaAvas. (a) Petrography of the Sediments. The sedimentary material varies in colour from pale green, through various shades of grey and brown, to bright red. It is fine-grained, compact, and usually hard, resisting the action of the 1 «Mineralogy of Scotland’ vol. ii (1901) pp. 1388-140, 145, &e. 476 DR. A. JOWETT ON THE [Oct. 1913, waves better than the volcanic rock in which it occurs. It breaks most easily along the bedding-planes, the newly-broken surface being covered with mica-flakes. Extremely fine-grained layers alternate with relatively coarser sediment. In the fissures and cavities, the bedding is less horizontal and regular than in the sheets of sediment. High powers of the microscope are necessary for the determination of the minerals even in the coarser layers, the finest material consisting of fragments too minute to be dealt with in an ordinary rock-section. The following minerals have been distinguished: quartz, felspar (orthoclase, microcline, and plagioclase twinned on the albite-plan), pale and dark micas, magnetite and red oxides of iron, augite, and chlorite. In addition, a few small fragments of glassy lava containing minute felspar-laths, have been found in almost every section examined. These fragments are always of the same order in size as the mineral-fragments among which they occur. The fragments are generally angular, but the larger grains tend to be subangular. The relative proportions of the constituents vary much in different specimens, the coarser varieties being richer in quartz, felspar, and larger flakes of mica, and the finer-grained types containing more mica (in minute flakes) and chlorite. The pale-green sediments with abundant chlorite seem to be generally associated with amygda- loidal lavas containing felspar-phenocrysts ; but, on the whole, the sediments are very much alike, irrespective of their immediate surroundings. ‘The cementing material is usually calcite, which is frequently in optical continuity over small areas; sometimes it consists of chalcedonic silica. The material which forms the matrix of the well-rounded boulders of the true conglomerates interbedded with the lavas is very different from that described above, though the difference 1s perhaps more in degree than in kind. It is reddish or purplish-brown usually, and is much coarser-grained and softer. ‘The fragments are approximately equal in size, some being well rounded, others subangular and angular. The great majority of the fragments consist of felspathic lavas with considerable interstitial glass. The felspars are sometimes quite fresh, showing twinning of the Carlsbad, albite, and pericline types, and giving the extinction of labradorite. The glass is usually crowded with magnetite dust, and is amygda- loidal; but, with the exception of a few pseudomorphs after olivine, no other original minerals could be recognized init. If we may judge from the imperfect evidence available, the fragments are mainly of basaltic or andesitic lavas. A few rounded grains of quartz and flakes of muscovite also occur. Green chloritic material, in radial aggregates, forms the matrix. Thin beds of sediment similar to this, but without boulders, have been found among and at the surface of the conglomerates, and even among the lavas in a position similar to that of the horizontal sheets of sediment of the more usual fine-grained type. A ‘Vol. 69.] VOLCANIC ROCKS OF THE FORFARSHIRE COAST. ATT No satisfactory evidence has been obtained, such as to prove that cany of the sedimentary material among the lavas has accumulated as the result of direct ejection from volcanoes. It might simply be the product of the rearrangement in water of rock-waste derived from ‘an adjacent land-area, where gneissose or granitie rocks, or pre- existing sandstones, and volcanic rocks of Lower Old Red Sandstone age, Were exposed. The sandstones and fine conglomerates in the vicinity of the Red Head, south of and above the highest lava in the series, include a eonsiderable quantity of voleanie débris mixed with ordinary ‘sedimentary material. The volcanic fragments are very abundant in certain layers, and absent from others. They are sometimes well rounded ; but angular fragments, probably andesitic or basaltic, are always included. Quartz and pale and dark micas form the bulk of the remaining material, but fragments of red sandstone and chlorite-schist also occur. The cementing material consists chiefly of chalcedonic silica and red iron-onides. (6) Amygdaloidal Sediments. (1) The conditions of formation of cavities in the as been said as to the relations between the lavas and the sediments, it may not be unreasonable to assume that successive streams of molten rock were poured out into water in which fine sediment was constantly accumulating. The per- sistence of these conditions further suggests a gradual subsidence of the area, which, however, was varied from time to time by Stationary conditions—as indicated by the contemporaneous decom- position of some of the lavas; and by actual re-elevation and erosion, of which the interbedded conglomerates and the irregular surfaces upon which these ogitg lonienaties rest are nepenenelee lle evidence, A flow of liquid rock over unconsolidated sediment containing water can hardly take place without important effects being produced upon both the lava and the sediment. The examples of pitlow-structure mentioned above indicate how the lavas have been affected by being poured into water, for Tempest Anderson’ has shown that pillow-structure may be produced in shallow water. Further, the same author’ has described how the lava boils the water into which it is poured, producing explosious which throw masses of lava into the air. Such conditions will necessarily lead to the accumulation of a layer of clinker-like fragments upon the surface of the laya-stream. But, beyond examples of the baking of the sedimentary material by molten lava, we have no instance in modern volcanic phenomena yet described that furnishes a parallel to some of the peculiarities which may be observed in Forfarshire. The mechanical effect of the movement of the molten rock 1 “The Volcano of Matayanu in Savaii’ Q. J. G. S. vol. xvi (1910) p. 632. 2 Op. cit. p. 639 & pl. li. 478 DR. A. JOWETT ON THE (Oct. 1913, over the moist sediment has been to buckle up, distort and break the superficial layers, the lava sometimes forcing itself into the soft sediment; portions of the sediment were detached from the main mass and carried along in the lower portion of the lava-stream, assuming a roughly spheroidal form. Nodules of this kind embedded in lava have been found, varying from an inch to over a foot in diameter. The heating effect of the molten rock has been :— (i) To bake the sediment with which it came into contact, giving rise sometimes to new minerals, especially in the case where spheroidal lumps of sediment have been incorporated by the lava, and consequently subjected to a higher temperature for a longer: time. (ii) To boil the water in the sediment without allowing the steam to escape, thus producing spheroidal cavities within the unconsolidated sediment. ‘The whole of the sediment may be: rendered vesicular in this way, or the upper portion only. The cavities appear to have originated in the coarser layers of sediment, where the spaces between the particles were necessarily larger and where, in consequence, a greater amount of water would be stored. The finer layers are frequently bent and broken up in connexion with the provision of more space for these steam-cavities. Some of the spheroidal masses of sediment included within the lava possess this vesicular structure, as well as the sediment below the lava. The vesicular structure is also commoner in the interbedded sheets of sediment than in the sediment filling up the fissures, though it is not absent from the latter. The combination of mechanical movement with heating has led to an elongation of the vesicles in the direction of flow, similar to that of the gas-cavities in slaggy lavas. In one example, a mass of sediment 3 feet in diameter and 9 inches thick may be seen to rest upon a sheet of lava, the rock above and around it having been completely removed. From its nether surface wedges of its sub- stance project into crevices in the lava beneath. It is composed of finely stratified, very fine-grained sediment, the outer layers of which are roughly parallel to the external surfaces of the mass ; but in the interior the material is crumpled up, and the layers are separated one from the other and sometimes broken across. The narrowest cavities are filled with chalcedony; larger ones are lined with chalcedony, with quartz in the interior; and in the largest, the order is chalcedony, then quartz, with calcite in the centre. In some cases the chalcedony is succeeded by radial aggregates of needle-shaped green crystals with high double refraction, probably epidote. It seems clear that, unless the cavities had been filled with gases until the sediment solidified, they could not have continued to exist under the pressure of the superincumbent lava. A detailed description of an instance of the effect of heat unaccompanied by mechanical movement may not be out of place- (Pl. XLV, fig. 4 & Pl. XLVI, fig. 6). The sediment is contained - Vol. 69.] VOLCANIC ROCKS OF THE FORFARSHIRE Coast. 79 in a large cavity, 14 inches deep, in compact lava. A vertical section of the cavity and its contents has fortunately been made by waye-action at the foot of the cliff. The plane of the section is ‘ such that the cavity appears to be completely enclosed by the lava. without any obvious connexion with the surface. The lower part only of the cavity contains sediment; the bedding of the sediment. is undisturbed, and the sediment is not altered where in contact with the lava. It seems certain that the cavity was one of the usual steam-cavities’ in the lava which somehow came into com- munication with the surface, and so became partly filled with fine- sediment. The lowest part of the cavity contains well-stratified, compact, sediment without amygdales. Above this the sediment is full of amygdales, consisting of calcite and chlorite, and the stratification is broken up, portions of the finer-grained layers being set in the solid mass at all angles. The upper part of the cavity is filled with green chloritic material enclosing a large crystal of calcite.. Obviously, the breaking up ot the sediment was not due to external pressure, because the walls of the cavity are intact and the sediment at the bottom is quite undisturbed. The only explanation that seems at all likely is that the sediment was deposited in. water in the cavity, and before this was quite filled another sheet of molten rock flowed over the surface of the already cooled lava. in which the cavity occurs. ‘he fresh access of heat boiled the water in the cavity from the surface without being sufficient to penetrate to its base, just as water may be boiled near the top of a test-tube while the lower part is cool enough to be held in the hand. The steam was unable to escape, owing to the sealing- up of the outlet of the cavity by the lava that supplied the heat, and the sediment consolidated with its upper layers full of vesicles. which, as well as the empty upper part of the cavity, ultimately became filled with secondary minerals. Hxamples of small fissures filled with amygdaloidal sediment in the base of a lava-stream have been observed near the ‘ Spectacle.” The fissures die out upwards, and it seems impossible for the sediment to have entered from above. I can only conclude that the lava boiled the water in the sediment over which it was poured, and the wet sediment was forced up into the crevices in the nether surface of the lava-stream. Amygdaloidal cavities have also been occasionally observed im the lower portion of the sediment where it is in contact with the lava beneath. They occur frequently, too, in the sediment that cements the loose blocks at the surfaces of lava-streams. It is possible that some of these instances may be due to the escape: of gases from the lava during the accumulation of the sediment. 1 A similarly-shaped cavity, 1 foot in diameter, in the same lava only a few feet. away was lined with chalcedony, inside which was a layer of bipyramidal quartz-crystals with a large hollow in the interior partly filled by crystals. of calcite and selenite. This is simply a rather large amygdale, occurring in a cavity which did not communicate with the surface. 480 DR. A. JOWETT ON THE [Oct. 1913, (2) The composition of the amygdales in the sedi- ments.—The minerals filling the amygdaloidal cavities in the sediments are practically the same as those found in the lavas. Calcite is perhaps the commonest, und under the microscope can be seen to have grown from the sides of the cavities as little dogtooth crystals, the rest of the interior of the cavity being then one mass of calcite in crystalline continuity. The cavities are often lined, and sometimes filled, with green chloritic material, in fibrous spherulitic aggregates, and sometimes with a green pleochroic and highly doubly-refracting fibrous mineral. Opal, chalcedony, and quartz have also been noted, and the amygdales are occasionally stained red with iron-oxides. (c) Metamorphism of the Sediments. The most characteristic secondary mineral produced in the sediments by thermo-metamorpbism is brown to golden-yellow in thin section, possesses perfect cleavage, and extinguishes parallel to the cleavage. It is slightly pleochroic and very strongly doubly refracting. It has no definite crystal-outline, only occurring in small, roughly square sections. It most closely resembles astro- phyllite. The mineral is present in quantity, roughly parallel to, but away from, the contact-zone in the nodules of sediment enclosed in lava, and also occurs in other sections of baked sed:ment. A rude foliation, due to the development of secondary mica in a narrow zone parallel to the surface of contact, occurs in one of the sediments in contact with a basalt. The basalt itself has a thin selvage of tachylyte with a few felspar-microliths. VY. Fauut-Brecotas. The most striking example is that of the Rock of St. Skae, which clearly owes its power to resist the elements more to its reinforce- ment by a multitude of veins of quartz, than to the dyke-rock that apparently forms its core. The material filling the north-and-south fractures is seen, under the microscope, to consist of ferruginous chalcedonic silica and quartz, with a curious banded effect simulating the flow-structure of rhyolites. The transverse veins are obviously more recent, as they break across the others, in some cases binding together a breccia in which fragmenta of the older quartz-veins are included. ‘Their silica is entirely eryptocrystalline. The excessive alteration of the volcanic rocks adjacent to the fault suggests at once a probable source of the silica in the veins. Other examples may be seen about a quarter of a mile west of Montroseness Lighthouse, east of Mains of Usan, and on the south side of Lunan Bay. A dyke-like fault-breccia occurs a quarter of a mile west of Boddin Point, in which calcite, as well as silica, is deposited in the vein. - Vol. 69.] VOLCANIC ROCKS OF THE FORFARSHIRE COAST. 481 At Dunninald Den, the fault-breccia consists of a broken-up mass of volcanic rock and of the sediment usually found among the lavas, the whole being consolidated by secondary silica. VI. Coxciusions. The Lower Old Red Sandstone rocks in this area furnish abundant evidence of a long-continued series of volcanic eruptions. The products of the eruptions are lavas which appear to have been poured out in water in which fine sediment was accumulating, the lava being much fissured and the fissures and cavities in it being filled with sediment. Lenticular beds of conglomerate resting upon denuded surfaces of volcanic rocks indicate that the volcanic material occasionally appeared above the water, although the most prevalent conditions were those of subsidence. A rude pillow-structure has been observed in the basal portion of some of the lava-flows. No definite pyroclastic material has been found. The rocks are almost entirely olivine-basalts, though in a few of them olivine is not present, its place being taken by rhombic pyroxene. It is possible that some of these may be basic andesites, but their felspars are as basic as those of the ‘ty pical basalts, and their structures also correspond with those of some of the types rich in olivine. A few dykes of Lower Old Red Sandstone age occur, which are less basic than any of the lavas. ‘They may be termed porphyrites. Several of the fault-breccias have been cemented with silica derived from the decomposition of the adjoining volcanic rocks, and in consequence are better able to resist the action of the weather, thus producing features outwardly similar to dykes, The fine sediments associated with the lavas bear evident traces of the pouring over them of molten rock prior to their consolidation. The effects of deformation due to mechanical stress acting on un- consolidated sediments, mineralogical changes, and cavities (probably due to the boiling of water in the sediments or the bubbling of gases through them), the cavities being now oceupied by secondary minerals, have all been observed in these sedimentary rocks. Incidentally, the examination of the coast-sections has revealed the presence, in the south-west of Lunan Bay, of what is probably amass of Upper Old Red Sandstone resting unconformably upon the lavas of Lower Old Red Sandstone age. My best thanks are due to Prof. Sir Thomas H. Holland, K.C.LE., for providing me with every facility for carrying out this piece of work, and for his kind help and advice duringits progress. I am also deeply indepted to Dr. G. Hickling, who not only suggested the work to me, and placed at my disposal his own intimate knowledge of the locality, but has also assisted me throughout with friendly advice and criticism. 482 DR. A. JOWELL ON THE [Oct. 1913, EXPLANATION OF PLATES XLY & XLVI. Prats XLY. [Illustrating the relations between the lavas and the sediments. | Fig. 1. Cliff-section south of Kirk Loch. The compact lava at the base becomes increasingly fissured, and passes into loose blocks above. All the fissures and the spaces between the blocks are filled with fine sediment. ‘The section shows about 8 feet vertically. 2. Horizontal and vertical section on the shore south of Rock Skelly. A network of sandstone-filled fissures is shown in plan in the foreground. The handle of the hammer rests against a mass of sandstone which is partly horizontal and partly almost vertical. 3. Stack on the shore in Kirk Loch. Vertical height = about 12 feet. Horizontal lenticular beds of sandstone 3 to 6 inches thick among’ the lava near the base of the section. 4. Cavity in lava partly filled by sediment; at the base of a cliff east of Dunninald Den. ‘The stratitication of the sediment in the lower part of the cavity is undisturbed; above, the layers of sediment are broken, and amygdales appear (see P}. XLVI, fig. 6). At the top of the figure, amygdaloidal sediment may be seen entirely filling another: cavity. Puate XLVI. [Microphotegraphs of rocks from the Forfarshire coast. | Fig. 1. Enstatite-olivine-basalt, near Montroseness. Phenoerysts ot labradorite: and fresh enstatite. Olivine, labradorite, granular augite, magnetite, and dusty interstitial glass in the ground-mass. ‘The olivine occurs- as serpentinous pseudomorphs. with borders of hematite. 20. 2, Enstatite-basalt, south-west of Fishtown of Usan. Phenoerysts of basic labradorite and bastite pseudomorphs after rhombic pyroxene: in a glassy ground-mass full of magnetite dust, with felspar microlites. Interesting intergrowths of felspar and pyroxene occur. 20. 3. Olivine-basalt (normal type) on the shore south of Rock Skelly. Pseudo- morphs in serpentine and hematite after olivine-phenocrysts. The ground-mass shows microporpbyritic labradorite, augite, magnetite, and interstitial glass. 2O. 4, Olivine-basalt east of Ethie Haven. Normal type, with holocrystalline ground-mass. Minerals as in fig. 3. X20. 5. Glomeroporphyritie olivine-basalt, South Mains Quarry, Ethie. The- glomeroporphyritic aggregates contain olivine (serpentine and hematite pseudomorphs), twinned augite, and labradorite. Felspar, granular augite, iron-oxides, and a little interstitial glass occur in the ground-mass, which indicates’ flow-structure. This type is on the- whole less basic than usual. > 20. 6. Amygdaloidal sandstone from a cavity in Java east of Dunninald Den (Pl. XLV, fig. 4). The finer layers of sediment appear to have broken. up while the coarser sediment was still unconsolidated. The amygdales contain chlorite and calcite. x6. DiscussIon. Dr. J. W. Evans remarked on the interest of the paper and om the clearness with which the Author had placed the facts and his. conclusions from them before the Society. It was remarkable that the Lower Old Red Sandstone lavas of this area should be so. much more basic than those of the Cheyiots. The speaker was still inclined to believe that many of the conglomerates were due to _ Quart. Journ. Geor. Soc. Vor. LXIX, Pr. XLV. A. J 9 Photo. Bemrose, Collo. Derby. LAVAS AND SANDSTONES OF THE FORFARSHIRE COAST. - Quart. Journ. Geor. Soc. Vor. LXIX, Pt. XLVI. Fg > oy ope te Pah gle 2 a} ae ee ae A.J. Photo. Bemrose, Collo, Derby. MICROPHOTOGRAPHS OF ROCKS FROM THE FORFARSHIRE COAST. i. 4 Vol. 69.} VOLCANIC ROCKS OF THE FORFARSHIRE COAST. 483 torrent-action. How did the Author explain the occurrence of the sedimentary material in the interstices of the lava? Was it washed in by the water of a lake, or by rain-water, or was it the result of eeolian action? The suggestion that cavities were formed by steam in sedimentary rocks below a lava-flow was very valuable. Dr. J. VY. Etsprn remarked on the petrographical interest of the paper. Some of the rock-types appeared to be rich in magnesia, and the augites might be expected to show the basal striation characteristic of such rocks in other areas. He asked whether these various rock-types occurred in separate lava-flows; or in different parts of the same flow. The character of the phenocrysts suggested an origin from a differentiated magma-basin. It would be interesting to know what kind of rocks marked the dyke-phase of these eruptions. The AurHor thanked the Fellows for their kind reception of his paper. Inreply to Dr. Evans, he said that true conglomerates, indicating the action of strong currents, are occasionally interbedded with the lavas. The fragments of slaggy lava cemented by fine sediment are found at the surface of almost every lava-flow, and were probably produced simultaneously with the lava below. He stated, in reply to Dr. Elsden, that each of the types of volcanic rock mentioned generally includes several sheets of lava. None of the augite-crystals show basal striation. ‘The few dykes consist of much-weathered rock, less basic than the lavas, no olivine and very little pyroxene being present. 484 MR. M. ODLING ON THE [Oct. 1913, 22. The Batnontan Rocks of the Oxrorn District. By M. Optine, M.A., B.Sc., F.G.S. (Read May 7th, 1913.) [Purares XLVII & XLVIII.] ConreEnts. Page Lin troducti ont ys -paces-macecunseeaeeneepeececchia so: seca. 484 iS General Deserip tion 2... as.- ea. ceeee sess se eecee 484 SD etailscotySectionsisereecaec cose eeetceer nce ee eecee 488 IBY; Palesombolo py neseesececasce-y-ace see eee oe eae se eee ee 501 Wen C hemiucala@ omppositi online eee eee eee see ee ses sence 504 VilEeRetrolo gy seins Suanaeteat uence seco Naa ty men tue Ges cera 506 Vil. Correlation, and Conditions of Deposition......... 507 I. InrRopuction. / Tats work was undertaken at the suggestion of Prof. Sollas, who supervised the work, and at his suggestion a large number of rock-sections have been examined. To Mr. W. W. Fisher, M.A., Public Analyst for Oxfordshire, Berkshire, & Buckinghamshire, I am indebted for much help and many valuable suggestions in carrying out the chemical analyses. I must also express my thanks to Mr. Linsdall Richardson for kindly verifying a number of my identifications, and for his help in the correlation of the beds with those of other districts. My thanks are also due to Mr. R. C. Sikes, M.Inst.C.E., for permission to visit the Ardley Cutting, and to the Directors of the ‘Oxford Portland-Cement Works, who, contrary to their regulations,. readily granted me permission to examine their quarry. II. Genrrat DeEscriprion. The rocks described in this paper form a well-defined series. sharply separated from the underlying beds, consisting of the Clypeus Grits on the west and Northampton Sands on the east ; and from the Oxford Clay, which nearly always conformably succeeds.” Throughout the series there is a general westward thickening, especially marked in the lower members of the Great Oolite. 1 Tn the Calvert boring, the whole of the Cornbrash is missing ; see A. M. Davies & J. Pringle, Q. J. G.S. vol. lxix (1913) p. 333. The description of the strata in that boring suggests to my mind the absence also of the lowest beds of the Oxford Clay of the district—the beds that probably represent the Kellaways Clay. Vol. 69. | BATHONIAN ROCKS OF THE OXFORD DISTRICT. 485» The Cornbrash. This consists of rubbly non-oolitic limestones of various degrees. of coarseness containing the normal Cornbrash fauna. ‘The total! thickness appears to be only about 17 feet,’ of which the upper: part is characterized by Microthyris lagenalis, the lower by T'ere- bratula intermedia. Cephalopods are far from abundant, there- being apparently but two records: namely, Clydoniceras ,discus from Kirtlington® and Macrocephalites macrocephalus from: Witney * The Forest Marble. This formation alters considerably when traced from west to east. On the west it consists for the most part of compact shelly and oolitic limestones, with only minor bands of clay or marl; in the centre of the district the false-bedded limestones are broken up into groups by numerous bands of horizontally-bedded marl or clay; while on the east clays and marls predominate, and the limestones on the whole are but slightly oolitic and very marly. The thickness in the area under consideration is only from 21 to. 28 feet, while at Alderton, south-west of Malmesbury, the thickness. is about 60 feet.* The incoming of the Forest Marble is represented by a well- marked eroded surface at the top of the Great Oolite, which is often much ripple-marked and bored and locally covered with oysters ;, the lower beds of the Forest Marble also contain fragments of the underlying beds. The Great Oolite. Except for the uppermost part, which approaches the Forest Marble in lithological character (so much so that in 1860 Prof. Phillips included the top of the Great Oolite in the Forest Marble’ ; this he corrected in his ‘ Geology of Oxford,’ in 1871), the Great Oolite contrasts remarkably with the overlying Forest Marble, in that the series 1s almost entirely calcareous, false bedding is absent, and the rocks are as a whole much finer in texture. The eastward thinning of the Great Oolite is very remarkable: although there. are certain beds which are easily recognizable in all the sections, the intervening beds are found to vary considerably, both in thick- ness and in lithological character, and it seems probable that some. of them actually die out by a series of overlaps before reaching the east of the district. 1 H. B. Woodward, ‘Geology of the Country round Oxford’ Mem. Geol. Surv. 1908, p. 4. 2 J. Phillips, ‘Geology of Oxford & the Valley of the Thames’ 1871, . 248. i 3-H. B. Woodward, ‘ Jurassic Rocks of Britain’ Mem. Geol. Surv. vol. iv (1894) p. 446. 48. H. Reynolds & A. Vaughan, Q. J. G.S. vol. lviii (1902), p.. 748. 5 J. Phillips, Q. J. G. 8. vol. xvi (1860) p. 118. [ 486 ] AapaaVy ["w oq prnogs ,JxaATRO , eAoqe ¥ om) fy oq prnoys , YSnoroqueyy Suo7T , spx0M or} oaoqe ¥ ory] sopoya.10g =(ud) RSS aay Pe gaa aS OL SIDA Sen ae SAB AIC sprog jedrourtd ¢ pb € (a I oO SOT JO aos "JOUISIG. P4oyxOQ oy} ur SHYNSOdxad NVINOHLVG jedioursd oy} mors 03 depy *T B1yy ysnoroqueyy YY duoT uo oe (23) /OIS u0}-durp4.a Sy} (P)\ “Nag qeusjongY AQ|PAV/ARG., Dy) BA FoIMa | NE \ NS pe ga MLA R wey .sulIyxIng - —- Vol. 69.] BATHONIAN ROCKS OF THE OXFORD DISTRICT. 487 Mr. Barrow has divided the Great Oolite of the Ardley section into three divisions—designated respectively Ist, 2nd, and 38rd Blocks, taken in descending order’; the lower part of the 3rd Block, however, I am inclined to separate off as being Fullonian. Mr. Barrow’s divisions are adopted in this paper, with the exception that the break between Block 1 and Block 2 proves to be situated at the base of the First Terebratula Bed instead of at the top of it. Fullonian. In this district the Fullonian rocks are now recognizable only in the Ardley section, but they have been described in some detail by Mr. A. E. Walford from the Stonesfield and Chipping-Norton districts”; and also by Mr. L. Richardson from the latter district.’ The upper beds consist of compact, very fossiliferous limestones ; while the lower part is almost entirely composed of clays and sandy beds, often of a remarkably green colour. The lowest bed, the ‘Chipping-Norton Limestone,’ consists of a very argillaceous, somewhat sandy limestone, which in the Ardley Section is crowded with Fhynchonelle, while on the east it consists chiefly of buff- coloured limestone. The following beds are valuable for purposes of correlation :— Cornprasi. Terebratula-intermedia Beds. Forest Marsie. Great Oouits. Cream-Cheese Bed, passing down into the Fossiliferous Cream-Cheese Bed. First Terebratula Bed. Second Terebratula Bed. Verinea Rock. Roach Bed. FULLONIAN. Fuller’s-Earth Rock. Rhynchonella and Inoceramus Beds. Astarte Limestone 1 “Summary of Progress of the Geological Survey for 1907’ Mem. Geol. Sury. 1908, pp. 149-50; & Proc. Geol. Assoc. vol. xxi (1909-10) pp. 40 e¢ segq. 2 «On some New Oolitic Rocks in North Oxfordshire’ Buckingham, 1906 ; also Rep. Brit. Assoc. 1894 (Oxford) p. 304, ibid. 1895 (Ipswich) p. 414, & ibid. 1896 (Liverpool) p. 356. 3 «Inferior Oolite & Contiguous Deposits of the Chipping-Norton District’ Proc. Cotteswold Nat. F. Club, vol. xvii, pt. 2 (1911) pp. 195 et seqq. Q. J. G.S. No, 275, 2x 488 MR. M. ODLING ON THB [ Oct. 1913, Fig. 2.—Section from Ardley to Fritwell Tunnel, G.W.R. (new Birmingham main line) on the scale of about 25 inches to the mile. III. Deratts or Sections. (a)’ Ardley Section (fig. 2). Mo BET A very complete section was Be ne afforded by the cutting on the Es Great Western Railway (new 2 as Birmingham main line) between Be Bucknall Bridge and _ Fritwell ae Tunnel. In a distance of about 33 miles all the beds were exposed, from the base of the Cornbrash to the top of the Upper Lias. 5 p The beds may be described as 2c YH] undulating, with a general south- ee Sip easterly dip; about two-thirds of ne J the way between the Fewcot & o rel Somerton Road and the Feweot & nt Middieton Road, a reversed fault AN with a north-westerly downthrow brings the uppermost beds of the oe Forest Marble against the basal g 5 beds of the Great Oolite. The es cutting, therefore, virtually affords dy two sections. 33 7 South-east of the fault, all the Ege sae nnno vf beds are exposed, from the base cam of the Forest Marble to near the a base of the Chipping-Norton Jime- stone Series; while, north-west of the fault, the beds from the base of the Cornbrash to the top of the Upper Lias are exposed. The a complete section thus afforded is ‘5 as follows :— CorNBrAsH (as a subsoil in the fields near the fault). Thickness in feet inches. Forest MarB ie. TBUME CMS cacoasscocnesada 2 9 False-bedded limestones 5 6 a8 Bine clayeyen tee is g oy Flaggy limestones ..... 9 9 ¢ BR Dark-blue and green Sa (au Saas cla x 0 g yy wosduiney3z0N Ny’ eacosqconscadoy daadc Letters prefixed to headings of sections refer to the map (fig. 1} p. 486. - Vol. 69.] BATHONIAN ROCKS OF THE OXFORD DISTRICT. 489 Thickness in feet inches, Gruat OoxiTe. (Bed 1, Cream-Cheese Bed (often largely removed by | erosion prior to the deposition of the Forest Marble). This consists almost entirely of amor- phous carbonate of lime, without shell-fragments OP OOMG ANS coneroboavasuoceqovanspadoudeHsusonanbe Oto2 0 . Fossiliferous Cream-Cheese Bed, This bed merges into the above, but is distinguished from it by the presence of numerous shell-fragments; the following fossils occur :—Nerinea eudesti Mor. & Lye,, Modiola imbricata Sow., Pinna cancellata Iseniin, eoaGl MeRAomEilles SD. scacadcaconsdacnececoecnder 4 0 | Bed 3. Compact fine-grained limestone, with occasional OOlipla si Meee ds ctiac stacks nsachceepntte Senaek eon avaise et 3 0 | Bed 4. Yellow marl; fragments of Hchinobrissus sp. COMM OMeRE eaten ee oe caecum ase cectee cece ee nnasceee eas 0 4 | Bed 5. First Terebratula Bed: a marly limestone ( crowded with 7. (Hpithyris) bathonica 8. Buck. 0 6 a eo} oO Qu i) Block i. Well-marked eroded surface, (Bed 6. Compact white limestone, with occasional ooliths, 1 9 Bed 7. Second Terebratula Bed: a marly, friable, | fossiliferous limestone, yielding 7. (Hpithyris) bathonica 8S. Buck., Modiola imbricata Sow., | Lima cardiiformis Sow., Plagiostoma (2) pune- tatum (Sow.), Hchinobrissus woodwardi Wright, enn eleG Ota S Whos aerate sane nt tee aceats cole asitiee Bed 8. Creamy white limestone, with a few Nerinea...... if 0 es 9. Nerinea Rock, a compact limestone almost entirely composed of specimens of Nerinea aff. Juniculus Desl., in a marly matrix .................. 1 0 | Bed 10. Soft marly limestone, with fragments of Phola- domya, Modiola, and Nerin@d@............+.0.0ee1- 00 1 0 ‘i | Bed 11. Freestone. This is the highest bed from which Pe Clypeus mullert Wright has been obtained ; ae Nautilus subtruncatus Mor. & Lye. also occurs... 1 0 2 | Bed i2. Marly parting, very persistent throughout the 9 | Beds Cuttin Pes poaatan sea ueciasasutenstaiaastieesasosesatoen eeseans 0 1 { | 13t020. Eight beds of compact limestone, with few | HOSTTIIC) aesaes ea aa erica os anced SNS tame eT ee amc meRiaeaeeeeaan 8 0) | Bed 21. Roach Bed. ‘This bed has been described by } Mr. Barrow as follows ':—‘ A somewhat siliceous | limestone from which the fossils are dissolved | out ... leaving a curiously porous-looking rock.’ The bed is highly fossiliferous, but the fossils | occur mostly as casts, and are ill-preserved ; the following have been identified :— Nerinea aff. | Suniculus Des)., Cyprina sp., Corbicella bathonica | Mor. & Lyc., Lima carditformis Sow., Gram- matodon hirsonensis (d’Arch.), Modiola imbricata \ Sow., Pleuromya goldfussi Lyc.,and Trigonia sp. 0 6to8 1 Proc. Geol. Assoc. vol. xxi (1909-10) p. 42; & ‘Summary of Progress of the Geological Survey for 1907’ Mem. Geol. Sury. 1908, p. 150. 2k 2 490 FULLONIAN. (Bed 28. Upper Fullonian. — 2. Blue clay, quickly weathering brown 3. Sandy argillaceous limestone, finely laminated, Bed 32. Beds 33, 34, &35. MR. M. ODLING ON THE Thickness mm feet yielding Terehratula sp., Ostrea sowerbyi Lyc., Cypricardia rostrata Sow., and radioles of Cio nN avord Key aa isiiereaBeaneratoe ancdacnecach aeaschhoceccusasoor 0. Argillaceous limestone in two beds, the lower one being rather sandy . Hard grey limestone, largely composed of skell- fragments, containing Terebratula sp., Modiola imbricata Sow., Ostrea sowerbyi Lyc., and Lima CUPOMUORMIDS 'SOW> 2c000200002200000000000000800060000000C . Grey, laminated, sandy limestone, with a few specimens of Ostrea sowerbyi Lyc. ............0000-+ Compact yellow limestone, sometimes grey, yield- ing Rhynchonella varians Schloth., Rh. sp., Tere- bratula ct. globata Sow., Ceromya concentrica Sow., Cypricardia rostrata Sow., C. bathonica dVOrb., Homomya vezelayi Mor. & Lyc., Lima cardiiformis Sow., Modiola imbricata Sow., Pholadomya deltoidea Sow., Ph. heraulti Ag., and Pleuromya ef. scarburgensis Mor. & Lye. ... . Sandy clay ; upper part blue, lower part brown... . Fuller’s-Earth Rock: a compact non-oolitic limestone with three clay-partings; it yields Teloceras subcontractum Mor. & Lyc., Natica pyramidata Mor. & Lye., Ceromya concentrica Sow., Cypricardia restrata Sow., C. bathonica d’Orb., Gresslya peregrina Phil., Lima cardii- formis Sow., Lucina bellona WOrb., Modiola imbricata Sow., Ostrea sowerbyt Lyc., Pholado- mya heraulti Ag., Ph. deltoidea Sow., Pleuromya cf. sinistra Ag., Terebratula globata Sow., Rhyn- chonella concinna auctt., Rh. varians Schloth., and Clypeus mulleri Wright Local sandy parting Rhynchonella and Inoceramus Beds: blue argillaceous limestones and clays, focally divisible into three. They yield Acteonina gigantea Mor. & Lye., Natica pyramidata Mor. & Lye., NV. globosa Reem., Camptonectes lens (Sow.), Ceromya concen- trica Sow., Gervillia aff. ovata Sow., Inoceramus obliquus Lye., Lima cardiiformis Sow., Modiola imbricata Sow., Ostrea sowerbyi Lyc., Pecten sp., Pholadumya heraulti Ag., Rhynchonella concinna auctt., TZerebratula globata Sow., Acrosalenia wiltonti Wright, Clypeus mulleri Wright, C7. ploti Wright, Hchinobrissus sp, and Isastrea LomiatatamWa tne. s..2o scsi one aceeecks os eens oceans Unconformity, especially well shown on the site of the northern end of Ardley Railway-Station, where Beds a & 6 of the Nexran Beds are absent; this unconformity marks the position of the Stonesfield Slates at Stonesfield. bo [Oct. 19133 inches. 6. ge) - Vol. 69.] BATHONIAN ROCKS OF THE OXFORD DISTRICT, 49] Thickness in feet inches. Nexran Beds: these consist for the most part of rapid alternations of greenish and blackish sands and clays; the lithological character of the dif- ferent beds yaries considerably within a very short distance ; only the following general section Gail, WaSREOME, 108 EMVEM ooscoovcacdoscedonouedod about 18 0 (a) Compact green clay, with much wood...... Oto3 3 (0) Green clay, yielding many specimens of Clegraliline, CMEC TO VIN, 5 55ceecececceceseuce Otol O (c) Laminated dark and light clay, locally aulOstalola Chee seese eer cc cereeece ca eeeseneces We aS) (d) Grey and green sands, locally replaced by a sandy limestone with rootlets ......... lto3 0 (e) Astarte Limestone: a pale greyish- green sandy limestone, crowded with specimens ot 4Asfarte angulata Mor. & Lyc., and often containing rootlets ...... ltol 6 (f) Dark-green clays yielding Cardium incertum Phil., C. stricklandi Mor. & Lyc., and Astarte angulata Mor. & Lye. ............ 1 (g) Dark-green clays; unfossiliferous, except at the extreme base, where there is a band of Ostrea sowerbhyi Lyc...........-2++- 0 6 (h) Grey clays and sand, becoming darker at - tien base; Maan saaremrant cre sete cma nes ctadcaty sh 3 6 (2). Ginsein Clay Sescccdavonccncseseocoaaeoasee re steals Z Fullonian. Lower (se) Ce aa a Chipping-Norton Limestone Series, consist- ing of: (7) Grey calcareous sandy clay, yielding Pinna cancellata Bean, Modiola imbricata Sow., endl AeOHCIUS STO. ocacccascoen Goosetenecosecese 2 6 (4) Bird’s-Nest Rock: a hard, sandy, argil- laceous limestone with numerous black specks,! which quickly weathers to a sandy clay containing Hemicidaris bra- vendert Wright, Rhynchonella sp., Pinna cancellata Bean, Ostrea sowerbyi Lye., Modiola imbricata Sow., and Zigzagiceras wagnert (Oppel),2 as also numerous curious tube-like segregations of coarse material, the possible origin of which is discussed on a later page (see p. 503). 8 6 ( Bed 7. False-bedded limestones, which pass laterally into a | pale lilac clay, when traced towards the tunnel 4 (? Chipping-Norton Limestone) ..................... 12to15 0 | Bed m. Black sand and clay ..... Da NGOe AEG een cei ro mBnucodse 15 6 jpbede7-mGreyish-—blacks sandstone seceeecese. eeeaee sy see.eee ener 8 0 0 \ Bed’ o; Compact dank/sandstone 2. .2).....-secceceecceeeee seers 10 Upper Liassie Clay (at the tunnel-mouth). Sands Northampton 1 (Mr, I. Richardson has noted black specks in the Chipping-Norton Lime- stone of Pointed-Heath Quarry near Chipping Norton; see ‘The Inferior Oolite & Contiguous Deposits of the Chipping-Norton District’ Proc. Cottesw. Nat. F. Club, vol. xvii, pt. 2 (1911) p. 229.] 2 Mr. 8. 8. Buckman considers that the specimen is probably an old-age mutation. 492 MR. M. ODLING ON THE [Oct. 1913, (6) Blackthorn Hill, south-east of Bicester. This section is largely based on the evidence obtained by the officers of H.M. Geological Survey, and by the Geologists’ Association, since the exposure was earthed up before this investigation had been begun. There was a clay-pit near here, which has been described by A. H. Green.’ I had, however, previously visited the section in company with Prof. Sollas in May 1908, while the excavation was in progress. The Cornbrash is very thin, heing only 5 feet 3 inches thick, and is covered by what may possibly be the Kellaways.* In the cutting the following section is recorded by the Survey °® :— Thickness in feet inches. Cornsrasu. (Lower part only. Rubbly, shelly, non-oolitic lime- BLOM) Star Ascmcaumcuen tects 2 tee ceion ee eine eRe Sec nee eee 5 0 one Sandy clay, with one pale marleband! esis yee 3 6 elard voreye Oolitic limestone lmeeesseeeees-eceeeee ee eee eeoe iL 6 Dark tenacious clay, passing down to lighter clay, with three pale marl-bands ............-...0.sec0eceee00e Gi 0 Forest Pale-grey blotchy limestone ................0c0eeeeeeeeeee oe 3 6 MarsBte. 4 Baleiclay parting se asiceche scence se ceccce-n ceoueceaeceee 0 6 Island! Clay AUHNENOMS ooacaaconscosaedscodoonsccosspeoeoasGcened 1 9 | Pallesoroy claves nuts mentees ete eee eee aoae” 6 | Bright bluish-green clay, passing down into grey clay {with (?) phosphatic nodules ................0.-e0ss0sea0 3 6 At the time of my visit, only the lower beds of the Cornbrash were exposed. They yielded the following fossils :— Pseudomonotis echinata (Sow.). Pholadomya deltoidea Sow. Pleuromya securiformis Phil. Pecten vagans Sow. Terebratula intermedia Sow. Ornithella obovata (Sow.. Near the top of the Forest Marble a greyish marly band contains numerous specimens of Gervillia cf. waltont Lye. The basal bed evidently corresponds with the basal clay in the Ardley section ; while the Forest Marble is, as a whole, more calcareous, and con- tains more wood than in that section. At Blackthorn Hill the whole of Block 1 of the Great Oolite was exposed, and about 18 inches of Block 2, the sequence being the same as in the Ardley section. (c) Islip Sections. One quarry, now no longer worked and much overgrown, is seen on the right-hand side of the road leading from the village to the mill. The section shows about 4 feet of Cornbrash resting upon the Forest Marble, which consists of about 4 to 6 feet of clay overlying false-bedded rock: the lower 6 to 8 feet is hidden by talus, and so overgrown that the thickness of the rock cannot be ascertained. A band of clay occurs at the very base of the quarry, 1 “Geology of the Country round Banbury, &e.’ Mem. Geol. Sury. 1864, 36-37. oe H. B. Woodward, ‘ Jurassic Rocks of Britain’ Mem. Geol. Sury. vol. iv (1894) p. 449. 3 G. Barrow, Proc. Geol. Assoc. vol. xxi (1909-10) p. 387; and ‘Summary of Progress of the Geological Survey for 1907’ Mem. Geol. Sury. 1908, p. 145. - Vol. 69.] BATHONIAN ROCKS OF THE OXFORD DISTRICT. 493 as is shown by the fact that water is always held up in ponds. Near this, in the railway-cutting the following section oceurs! :— Thickness in feet. Cornbrash, yielding Pseudomonotis echinata(Sow.), Homomya gibbosa Sow., Gresslya peregrina Phil., Modiola imbricata Sow., Pecten vagans Sow., Pholadomya deltoidea Sow., Pleuromya securiformis Phil., Terebratula intermedia Sow., Ornithella obovata (Sow.), and Pygurus TUB Otis, cadnéesadsonondedaabeddoosesesconoaendacocutogoensosasCnHede about 3 GIES) coocncodadcaacotbddcasaqondacaqasodeunnudesoudracosonecunoasdoadoor cacseosccedaccade 8 Hard, grey, oolitic limestone } Forest | 4 Flagey Geomronlite i Marble fl ‘ccc ‘ Civ eet ees ries tsa incloisviaain sutdiie we tioles's ssaieiceite vine vs atcs velo ve Se a5 White limestone containing Nerinea (Great Oolite), It is unfortunate that all the other exposures round Islip are now filled in: since, judging from the list given by Phillips, who mentions no less than sixty-five species from Islip, the exposures have been very fossiliferous.* (d) Oxford Portland-Cement Works, Kirtlington. The Cornbrash here forms a subsoil about 4 feet thick ; it is of the usual character, yields the usual fossils (see p. 501), and calls for no special note. The Forest Marble is only 17 feet thick, and is separated from the Cornbrash by a 2-inch band of clay; the following is the generalized section :— Thickness in feet inches. edgar Mans] vic] avy wrsancer ec ssostlose oasis serecec ceca seesieee 0 2 Bed b, Horizontally-bedded compact marl ............... 1 9 edges Mic] vaclayy ies oe steve a vascoseateas saa: nosewbecmasien 1 0 Bed d. False-bedded limestone .................0.00eeeeee eee 4 6 BedwenaNlarlyiclayay. wee esaneen ses iirc hiaeinrs Silos 3 0 Bed /f. False-bedded limestone ............... .s.ceceeeeeees 2 6 Bed g. Marl with limestone-nodules and ‘race’ ......... 1 9 Bed h. Compact marly limestone .....................00-05 1 0 Bed 7. Compact oolitic limestone ... ..................00005 0 6 Bed 7. False-bedded limestone ..... L Ago suis opbalneaeietn nese 1 0 17 2 Very few fossils occur, and, except for the bottom 18 inches, the limestones are all of a marly character. Great Oo.itE. Thickness in feet inches. ( Bed 1. ‘ Fossiliferous Cream -Cheese Bed’ (locally be- coming oolitic and containing corals) ............... i) . | Bed 2. Green clay (brown at the base, where it contains io njgmIbe) hg ates ease tsinsts soars siedicce sawictasee ynecseuleamaeie 0 Dede shelyelimeshoneey-casss sce c.cseesaaeeee-saces snes 1 4 em pbedi4e. Greeny claves: orcas saawnestesscess 2 az | Beds ; 2 4 15&16. Marly limestone (more compact towards the base) 3 0 — | Bed 17. Limestone (the lower part being the ‘ Nerinea ae ERO] 3) ons Scene acne er tee es ee eG | Beds | 18-20. Marly oolitic limestone (full thickness unknown). 4 6 Base of quarry. Geographically, this exposure occupies a position intermediate between the Ardley section and the Enslow-Bridge sections. One would consequently expect the thicknessés also to be intermediate: on comparing the thicknesses, however, with those in the Enslow- Bridge sections, we find that they are approximately identical; the decrease in thickness appears, therefore, to occur between this section and the Ardley section. Enslow-Bridge Sections. There are three quarries at Enslow Bridge: the Upper Green-Hill Quarry, the Lower Green-Hill Quarry, and the Gibraltar Quarry. Green- Hill Quarries.! Two quarries are opened on the side of the hill, near Bletchington Railway-Station, the upper of which exhibits the base of the Corn- brash and the top of the Forest Marble; the lower exhibits the base of the Forest Marble and the Great Oolite. Fortunately, the upper exposure is sufliciently deep to allow of the lowest beds being correlated with the upper beds of the lower quarry. The western end of the upper quarry is sufficiently close to the lower yuarry to allow of one complete section being shown in the correlation-table. (¢) Upper Quarry (Pl. XLVI, fig. 1). The Cornbrash is exposed to a depth of about 8 feet—which appears to be almost its full thickness *; the rock is very fossili- ferous, and of the usual character. The lower part consists of a bed of compact limestone, about 2 feet thick at the western end of the quarry, and only a foot thick at the eastern end, where there is a layer of rolled, concretionary, calcareous nodules at the base. The following fossils are especially abundant in this ex- posure :—Homomya gibbosa Sow. (very large specimens, measuring over 6 inches in length), Pholadomya deltoidea Sow., and Pseudo- monotis echinata (Sow.). 1 The upper quarry is figured in Proc. Geol. Assoc. vol. xxii (1911) pl. i, fig. 2; the base of the Cornbrash has, however, been drawn too high. 2 J. Phillips, Q.J.G.S. vol. xvi (1860) p. 117. - Vol. 69. |] BATHONIAN ROCKS OF THE OXFORD DISTRICT, 495 In the Forest Marble the beds vary considerably, both in thickness and in character, when traced from one end of ‘the quarry to the other: this may be, in reality, due to false bedding, which would be almost obscured if the direction of the currents were at right angles to the general trend of the section. The section is as follows :— Western end. Hiastern end. Thickness in fect. ‘Thickness in feet. Bed a. Sandy marl............... 13 Bed a. Sandy marl ............ 3y Bed 6. False-bedded white | 8 Bed 6. False-bedded white) ° OOM: cosotosnvodoooe J OOM stonavecnaogede | iBe0l Gs IIB TE socnonoonondooncee 8 Bed 6°. False-bedded white KONI Gabcdaeoceodcne Bed cl. Hlagey marl...-2...... 2 Bed c. Flaggy marl .......... SOS Be dines me Maig eer see secre ec cs Os Bed d'. | False-bedded Bed d. False-bedded ; 5) F 1 Sens = 1 a. limestones and limestones and b ah, Clabyprem once eeadas (Sean) Clay sear cmentchianten st }) (28) MOAI. Sooeaced0 13 1133" (f) Lower Quarry (Pl. XLYVII, fig. 2). Thickness in feet inches. Bed 6. Subsoil of false-bedded limestones ..................... about 2 0 HCC UC MAME EN Ae ypIIAN eee sca aisastsebe coeateoae oe eken ss see seas ueaeueceuee 2 0 Beda.” Halse-bedded! limestones and clays .-:..........2.2.-2.-00e---00- 7 6 Beate False-bedded limestones, sometimes replaced by ee | Stiff clay (with a very irregular base) ............c0cccece0eeeees 1 9 Thickness seen=about 12 3 Great Oo.irE. _ (Bed i. ‘ Fossiliferous Cream Cheese’ ............-.. from Oto I 9 q (with a very irregular waterworn upper surface). ra 4 Bed 2. Dark-green clay, with much wood (specimens mea- s suring 9 inches in diameter have been obtained)... 3 0 faa) | Bed 3. Brown sandy bed, with plant-remains .................. 0) 8 (Bed 4. ‘ First Zerebratula Bed,’ as in Gibraltar Quarry ...... 1 0 1 [Since the above was written, the quarry has been greatly deepened about the centre, and a pit has been sunk, with the object of draining off the water. The following addition to the section was noted (September 1915) :— Bed d. False-bedded limestones and clays ......................2.00+ about 8 feet. Bed e. Irregular oolitic marl and limestone, slightly false-bedded. 9 to 15 inches giving a total thickness for the Forest Marble of 21 feet 3 inches. The Great Oolite section is as follows :— Blue-hearted limestone (= Fossiliferous Cream-Cheese Bed)... 2 feet 2 inches. Deine lnlluvisinemonsein Gann \ aoocogodvaceaensecddneesouuedee Abuasoubuadagooe: 4 feet. Brown marly band with plant-remains ..................... about | foot. The section was carried down about 11 feet below this, the sequence being similar to that exposed in the Lower Green-Hill Quarry. | 496 MR. M, ODLING ON THE [Oct. 1913, Thickness in feet inches. ( Beds 5-10. Compact white limestones, with local marl-partings 10 0 Bed 11. ‘Second Terebratula Bed, as in Gibraltar Quarry... 2 0 ey Bedssl2lb:8 Compact himestonesies-.-asse-saecee re ssete-e seer eee 2 9 1, | Bed 16. Brown limestone, passing down into ‘Nerinea Rock’ 2 6 2 y deieel Iie lbeyrarboRyyeol Mandl > cospodoceocodacnsaoodaoncoecdnscondoceanne 6 — | Bed 18. Limestone, yielding numerous teeth and part of a aa lower jaw of 7eleosaurus brevidens Phil. ; also teeth of Strophodus and Pycnodus ...........0cceececee renee 9 \ Beds 19-20. Sandy limestones, with marl above ............... 2 6 Base of quarry. The green clay, Bed 2 in Block 1, is of especial interest, since it is from this bed that the remains of Cetiosaurus owoniensis Phil. were obtained; as this bed underlies the ‘ Fossiliferous Cream Cheese,’ the specimens must have been obtained from the Great Oolite, not from the Forest Marble. The beds down to the top of the ‘ First Terebratula Bed’ were originally included in the Forest Marble by Phillips,’ but afterwards included in the Great Oolite in his ‘ Geology of Oxford, &c.’ (g) Gibraltar Quarry? (fig. 3, p. 497). A very complete section is afforded in this exposure ; but, as the face of the quarry is almost vertical, a detailed collection from. some of the beds proved to be impossible. The details of the eroded surface of the Great Oolite were originally more easily observable in this section than in any of the others, since the Forest Marble was quarried back much farther than the Great. Oolite, thus leaving a large platform. Unfortunately, quarrying operations have now been carried down into the Great Oolite. The section in Gibraltar Quarry is as follows :— Thickness in feet inches. Subsoil of rnbbly Cornbrash, with the usual fossils............ 1 to 2 0 Forest MARBLE. Bed a. False-bedded, coarse, oolitic limestones .................00000+ 3 6 Bed}; Horizontallly-pedded (clay, -esea-eeesesee eee eee eee eee see 1 3 Bed c. False-bedded limestones and clays ..................020e0eee eee I~ 6 Bed d. Horizontally-bedded marly limestones ......................-. Il 6 Bed e. Compact limestone, false bedding shown on weathering ... 2 0 Bed 7. Horizontally-bedded marly oolite ...............ceeeeeeeeee eee 1 0 Bed g. Compact limestone, false bedding only apparent on weather- IG: has dissictetsw sek mataclsecalseve sold cseneceaee tee case cement 0 Bed #. Horizontally laminated marl ..................0e.ce0e0sceeeee ee 0 10 Bed i. False-bedded limestones and clays .............0:0e:e0seeeeee ees a 6 Beds 7, &, Horizontally-bedded alternations of limestones and Ip Wy SG y WIEBE Th TAGE, WANGIS Sooccsencacosoosdsccoepopsscescnosacsondesass 0 8 Well-marked eroded surface with Ostrea. 1 Q.J.G.S. vol. xvi (1860) p. 118. 2 This section has been described by C. J. Bayzand, Proc. Geol. Assoc. vol. xxi (1911) pp. 3&4, also pl. ii. Unfortunately, the divisions marked alongside the photograph are incorrect, and most of the fossils recorded from the Forest Marble on p. 3 (op cit.) come from Bed 5 of the Great Oolite. - Vol. 69. |} BATHONIAN ROCKS OF THE OXFORD DISTRICT. 497 Fig. 3.—Upper part of Gibraltar Quarry. Cornbrasgsh. Forest Marble \ | | | | | c | | | | ) ) Fossiliferous Cream - fj Cheese Bed (top of the Great: Oolite). M. O. photo. Great Oo.ire. Thickness in feet inches. ( Bed 1. Fossiliferous Cream-Cheese Bed, passing into an oolitic limestone at the northern end of the quarry. ‘The | following fossils have been obtained froin this bed :— Terebratula (Epithyris) bathonica 8. Buck., Nerinea eudesti Mor. & Lyc., and Modiola imbr icata Sow.. | Beds 2-4. Compact pure limestone, with a band of clay above he ai cubelowa tise ae sioaeentasaescuclanae ta caren e eee ene a3 Beds 5 & 6. Marly fine-grained limestone, more marly at the | base, and yielding numerous fossils: such as Astarte | { bo a) on angulata Mor. & Lye., Cardium buckmani Mor. & Lyc., Gervillia waltoni Lyc., Modiola imbricata Sow., Amberleya nodosa J. Buck., and Nerinea CMOESIE WOR, W5 UO, coocoadcsspecanaucco sous spsn¢cusuaobade 0 we Beds 7 & 8. Bluish-green clay, passing into a laminated brown CT age ser ete ciststte Mi ateclotin tk cnacart a a Pana pe poe 1 ; Bed 9. First Terebratula Bed: a marly bed crowded with 7. (Epithyris) bathonica 8. Buck. The bryozoa Bere- nicea diluviana Lamx., and B. archiact Haime' are often found encrusting the Terebratule. This bed | rests upon the eroded surface of Block 2, upon which | there is often a band of oysters, as also Jsastrea L limitata Lamx. and Thamnastrea lyelli BH. & H.... O 9: 1 See Proc. Geol. Assoc. vol. xxii (1911) pl. iii. Block 1. to 498 MR. M. ODLING ON THE [Oct. 1913, Thickness in feet inches. (Beds 10-12. Compact limestone with few fossils ............... 7 3 Bed 18. Second Zerebratula Bed: a marly limestone yielding T. (Epithyris) bathonica 8. Buck., Cyprina islipensis Lyc., Gresslya peregrina Phil., Lima cardiiformis i Sow., Modiola imbricata Sow., Ostrea ct. sowerbyt 4 Lye., Zrigonia sp., and Hybodus dorsalis Phil........ 1 3 < | Beds 14-23. “ Chiefly compact limestones, with a few specimens can of Neringa towards the base ..............2+.-+0+00-e+- 8 6 Bed 24. Nerinea Rock, similar to that which is exposed TE (JI ANGIE? SACOM pococurceoonoqecesbeenoopneccndemonc 1 9 | Beds Balle Clovinjarroy Wise Seon) .oorcoconconsoncenacbanvensdecnosdce 3 0 Base of quarry. (h) Bladon Quarry, near Woodstock. This section exposes the Forest Marble, capped by a rubbly subsoil ef Cornbrash, in which fossils are not so numerous as in most of the other exposures; this subsoil is from 1 to 4 feet thick. The section of the Forest Marble is as follows :— Thickness in feet. Bed a. Somewhat marly, false-bedded, oolitic limestones .................. 23 Bedsd=., "Blue:cl ayn Mn So jacosniss maine esiags seeen eae ees eR CE Ae Een ER EERE 2 Bed c. Somewhat marly, false-bedded, oolitic limestones .................. 3 iBedidea Blue compactpliniestomesiee peepee sree eee eee eeeee eee nee eee eee nee i Bed ie): Blucvclaysiecs assess us Patter setae cee cecwadees Ceches seeeee eek er see eee eee 3 Bed f. Blue argillaceous limestone (recognizable in the Hanborough Well- section). Rhynchonelle and spines of Hchini are abtndlamt.cecuas tae doscedacennreetstceesrcsne sacee abet set ee tment eer 1 Bedg. Very hard, compact, blue-hearted limestone, in three bands, showing the false bedding only after prolonged weathering! 14 Bed i. B lune -clayik doses canctassaeceeeenccis teeeenaet toes Meare eee se about 37 The thicknesses are considerably greater than in any of the Forest-Marble exposures on the east. (2) Hanborough Quarry (at the cross-road to Eynsham, east of the Railway-Station). About 2 feet of rubbly, very fossiliferous Cornbrash forms the subsoil of this section. The Forest Marble consists of 4 feet of biue clay, resting upon compact, shelly, oolitic hmestones, in which the false bedding is apparent only after prolonged weathering; the thickness of limestone exposed does not exceed 10 feet. 1 Included in the Great Oolite by A. H. Green, ‘Geology of the Country round Banbury, &e.’ Mem. Geol. Sury. 1864, p.27; seealso E. Hull, ‘Geology of the Country around Woodstock,’ Mem. Geol. Surv. 1859, p. 23. * [A well now being sunk within 200 yards of the quarry has shown that the thickness of clay is very irregular, varying from 22 to 4 feet, the lower part being very marly. ‘The clay rests upon an extremely irregular surface of the Fossiliferous Cream-Cheese Bed, which is here about 12 inches thick; this rests upon marly limestones, of which only a thickness of 2 feet has at present been plerced.—September 30th, 1913. | - Vol. 69. ] BATHONIAN ROCKS OF THE OXFORD DISTRICT. 499 (7) Hanborough Well, by the Station cottages. The thicknesses are given by the well-sinker ; and, as he is a quarryman in the Bladon and Gibraltar quarries, his descriptions. are to be relied on. Approximate thickness in feet. Rubbly limestone (Cornbrash): same as top of Bladon Quarry...... : Bedigaa snittblie clay, spassine tmtOMmOcks oyeets-e-seseseeeeee-ese-csese il iBeGl @, Sineillky lollivie, UbimEsworn) Soo coccesasetinseoedosececescdosssHaeeneHeEecee 1keel @, Cloninjaevets Ina SWONMIS Sosncaseedoncen dacs sac eacadocudcaeedEseedeedse HES CU um lelygter rer creep etmcmenasod sass seit ceases shmtes eelgnubecarimetmoncwen sing . WObhw ao On the evidence of the well-sinker, the blue argillaceous lime- stone (Bed f) of Bladon Quarry is the same as the shelly blue limestone (Bed 6) in the well; I was fortunate enough to be able to verify this. (k)* Hanborough Quarry (near Mill Wood) : western end of Long Hanborough. There are two quarries close together, which yield the following section. Southern Quarry. Worthern Quarry. Thickness in feet inches. Thickness in feet inches. Gravel............ 5to 6 0) Gravely wees: ok tes Otol 0) (Impersistent clay... O 6 Marl with Microthy- = ris lagenalis ...... 0 8 = | Compact limestone Limestone with Pseudo- 24 yielding Pseudo- monotis echinatu... 2 to 3 0 A monotis echinata.2 6 0 © } Dark clay-band ...... 0 4 IDE Okay sosceacoosdsa0n 0 4 Terebratula-interme- 2 0) Terebratula - intermedia {| dia Limestone. (seen) ILMANESOM® — covocacsovos 3 0 29 { Bluish-grey clay ......... 3 4 woe Coarse, shelly, oolitic 4 i) BS yl limestone. (seen) (1) Woodstock Railway-Cutting. A cutting on the Woodstock Branch of the Great Western Railway has been described by Mr. H. B. Woodward.’ The full thickness of the Cornbrash was here found to be 11 feet 8 inches, while that of the Forest Marble is stated to be 19 feet 6 inches. The Great Oolite was exposed for a depth of about 30 feet; the top bed is evidently the same as the oolitic type of the Fossiliferous Cream Cheese of Gibraltar Quarry ; also the bed with Astarte and Gervillia is evidently Bed 5, and the bottom bed the Second Tere- bratula Bed of the above-named quarry. 1 Misprinted (/) on the map (fig. 1, p. 486) north-west of the word Long in ‘Long Hanborough.’ 2 A fragment of an ammonite has been obtained from this bed; from the description given to me I have little doubt that it is Clydoniceras discus. ° ‘Jurassic Rocks of Britain’ Mem. Geol. Surv. vol. iv (1894) pp. 447, 373, 374, & 320. 500 MR, M. ODLING ON THE [ Oct. 1913, Notes on other Sections. There are now no sections exposed in the Stonesfield district. The sequence, however, at Stockey Bank, Stonesfield (1) has been worked out by a committee of the British Association.* It may be summarized as follows :— Limestones and marls, with many globose forms of Rhynchonella. Stonesfield Slate Series. Nexran Beds: green, black, and grey clays and limestones. Chipping-Norton Limestones. The sequence round Chipping Norton has been fully worked out by Mr. L. Richardson,* who largely confirms and adds to Mr. Wal- ford’s observations.® The sequence is similar to that at Stonesfield, except that the Stonesfield Slates are entirely or almost absent. The accounts supplied of well-sections are for the most part so vague as to be of little value. The descriptions given of the topmost bed of the Great Oolite suggest that the ‘ Cream-Cheese’ or ‘ Fossiliferous Cream-Cheese’ type of rock extends over a large area, occurring as far east as Witney and Bampton. On the south, in the boring at the Oxford City Brewery,‘ the Cornbrash is seen to be 17 feet thick, while 32 feet 8 inches is assigned to the Forest Marble. In assigning 88 feet to the Great Oolite, it is probable that the Fuller’s-Earth Rock and the ‘ Rhynchonella Beds’ have been in- cluded. The 283 feet of beds described as belonging to the Upper Estuarine Series are extremely suggestive of the Newran Beds of Ardley. The 16 feet of rock described as Inferior Oolite seems to agree more closely with the Chipping-Norton Limestone: the fragments of the cores preserved in the Museum of Practical Geology, Jermyn Street, London, do not resemble the Clypeus Grits of Fawler. The borings at Calvert (2), recently described by Dr. A. M. Davies & Mr. J. Pringle,’ are of great interest, the absence of the Cornbrash and possibly of the lower beds of the Oxford Clay being remarkable, as is the thickening of the Forest Marble. The absence of Neswran Beds bears out the evidence of uncon- formity noticed in the Ardley section. From the evidence of the specimens kindly shown to me by Dr. A. M. Davies, I am inclined to think that the Fullonian type of deposit predominated here until a later period, to the exclusion of true Great Oolite. 1 Rep. Brit. Assoc. (Oxford) 1894, p. 304; 2did. (Ipswich) 1895, p. 415; and ibid. (Liverpool) 1896, p. 356. * “Inferior Oolite & Contiguous Deposits of the Chipping-Norton District’ Proc. Cotteswold Nat. F. Club, vol. xvii, pt. 2 (1911) pp. 195 et segq. 3 ‘On some New Oolitic Rocks in North Oxfordshire’ Buckingham, 1906. 4 R. H. Tiddeman, ‘ Water-Supply of Oxfordshire’ Mem. Geol. Surv. 1910, p. 65. ° Q.J.G.S. vol. lxix (1913) p. 310. - Vol. 69.} BATHONIAN ROCKS OF THE OXFORD DISTRICT. 501 LV. PaLtzonroLocy. Cornbrash. The Cornbrash has yielded a very rich fauna of a constant character, the same assemblage being found in almost every ex- posure. The most noticeable absentees are the Cephalopods, which have only been recorded from Witney and Woodstock,’ where Macro- cephalites macrocephalus and Clydoniceras discus occur. The latter is also recorded from Kidlington.” This might be explained by the fact that in most of the exposures only the lower beds are exposed ; but the explanation is not wholly satisfactory, since J. macro- cephalus and Cl. discus certainly occur yery near the base in the Fleet, Weymouth. Most of the thirty-seven species mentioned in the Geological Survey Memoir’ as being the most abundant and characteristic species of the Cornbrash occur; and of the eighty-eight species recorded, the following fifteen occur in almost every exposure:— Pholadomya deltoidea Sow. Terebratula intermedia Sow. Ornithella obovata (Sow.). Serpula tricarinata Sow. Echinobrissus clunicularis (Lhwyd). Pugurus michelini Cott. Anabacia orbitulites Lam. Pseudomonotis echinata (Sow.). Gresslya peregrina Phil. Homomya gibbosa Sow. Modiola imbricata Sow. Pleuromya securiformis Phil. | Camptonectes lens (Sow.). | Pecten vagans Sow. Lima gibbosa Sow. | Of the eighty-eight species recorded, no less than seventy occur in the Cornbrash of Islip and Kidlington.* Forest Marble. The fauna of the Forest Marble is comparatively poor, consisting of but forty species, of which only the following nine are at all common :— Camptonectes lens (Sow.). Gervillia waltoni Lye. Modiola imbricata Sow. Peeten fibrosus Sow. Ostrea sowerbyt Lyc. Rhynchonella concinna auctt. Acrosalenia (spines). Pentacrinus (colunimals). | | | | Pecten vagans Sow. 1 A. B. Woodward, ‘ Jurassic Rocks of Britain’ Mem. Geol. Surv. vol. iv (1894) p. 446. 2 J. F. Blake, ‘ Fauna of the Cornbrash’ Monogr. Pal. Soc. 1905, p. 54. 8H. B. Woodward, op. supra cit. p. 434. 4 J. F. Whiteaves, ‘ Invertebrate Fauna of the Lower Oolites of Oxfordshire’ Rep. Brit. Assoc, 1860 (Oxford) Trans. Sect. p. 107. 502 MR. M. ODLING ON THE [Oct. 1913, It is to be noticed that such forms as Dictyothyris coarctata, ZLelleria digona, and Hudesia cardium haye only been recorded from Islip," while Apiocrinus parkinsoni has been recorded from one of the clay-bands at Kirtlngton, ? Oxford Portland-Cement Works,* but from which is uncertain ; probably it came from one of the bands in the Great Oolite, Block 1. Although A. parkinsoné has usually been considered a Bradford-Clay fossil, Prof. Reynolds & Dr. Vaughan have shown that the Bradford-Clay fauna occurs at several horizons in the upper part of the Great Oolite;* and so. there is no justification for assuming from the occurrence of this form the presence of a definite horizon. Great Oolite. The fauna of the Great Oolite (as defined in this paper) includes: about ninety species. In addition, nineteen species have been re- corded from the lower beds; but these probably came from the beds here classed as Fullonian. In the Great Oolite, when subdivided, we find that Block 1 is chiefly characterized by Nerineea eudesvi, while in Block 2 N. funi- culus is the more characteristic fossil ; Clypeus mullert only occurs in the lower part of Block 2, and has not been found in the upper beds: that is, not above the Nerinwa Rock. Block 3 is nowhere exposed, except in the Ardley section, where it will soon be obscured by the downwash of the clays; it is characteristically unfossiliferous, except for a few very badly pre- served fossils. Fullonian. Paleontologically, in this district the Fullonian is best con- sidered as being composed (1) of an upper series, including all the beds down to the top of the Stonesfield Slates; (2) the Stonesfield Slates; and (3) a lower series, consisting of the Newran Beds and the Chipping-Norton Limestone. The upper series contains forty- five species, while the Stonesfield Slates contain 194 species, and the Newran Beds contain forty-eight: since some of the species occur in more than one division, the total fauna of the Fullonian amounts to 245 species. Of this total ten are restricted to the upper beds, 133 to the Stonesfield Slates, and eighteen to the lower beds of the district. On reviewing the assemblage of fossils from the Bathonian rocks of the district, we find that of the 370 spevies recorded, 224 are restricted in range; of these no less than 133 are restricted to the Stonesfield Slates, and thirty-four to the Cornbrash. Of the 370, 1 J. KF. Whiteaves, ‘ Invertebrate Fauna of the Lower Oolites of Oxfordshire ” Rep. Brit. Assoc. 1860 (Oxford) Trans. Sect. p. 107; aud H. B. Woodward, ‘ Jurassic Rocks of Britain’ Mem. Geol. Surv. vol. iv (1894) p. 376. 2 Td. ibid. p. 375. 3 §. H. Reynolds & A. Vaughan, Q. J.G.S. vol. lviii (1902) p. 742. Vol. 69.] BATHONIAN ROCKS OF THE OXFORD DISTRICT. 503 only about eighty can be said to be at all common. Palxonto- logically, the only beds that can be recognized are as foliows :-— Cornbrash, characterized by Pseudomonotis echinata, Gresslya peregrina Terebratula intermedia, Ornithella obovata and Pygurus michelini. Great Oolite. Block 1. Gervillia waltoni, Nerinea eudesii, and Tere- bratula bathonica. Ist & 2nd ‘maxillata’ Terebratula bathonica, large and abundant. Beds. Neringa Rock. Nerinea ef. funiculus. Fullonian. Inoceramus obliquus, Rhynchonella sp., Clypeus Ehynchonella & ILnocera- mulleri, and Ostrea sowerbyi. mus Beds. Stonesfield Slates, charac- terized by Trigonia tmpressa. Gervillia acuta, and Stigo- ceras inicromphalus. Rk. F. Tomes * mentions thirty-four species of corals from the Bathonian, and divides them into seven bands, according to the localities from which they came. Of these, No. 1 is probably below the Stonesfield Slates, while Nos. 2, 3, & 4 are probably of the same age, since Mr. Walford mentions a coral-bed at Stones- field just above the ‘slates’, and on his own showing No. 2 is precisely in that position. Nos. 5 & 6 probably represent the coral- bed in Gibraltar Quarry, which grew on the eroded surface below the First Zerebratula Bed, and the coral-bed in the Fossiliferous Cream-Cheese Bed of the Oxford Portland-Cement Works. Bed 7 occurs in the Cornbrash at Fairford; this latter is of interest, since Stylina and Thamnastrea arachnoides are recorded from the Cornbrash near Buckingham.’ 7h. arachnoides is so typically Corallian, where it occurs with Stylina delabechei, that one feels some doubt as to whether this does not represent a small faulted outher of Corallian. A peculiar Structure referred to Annelid-Tubes from Bed & of the Chipping-Norton Limestone of the Ardley Section. (Pl. XLVIII, figs. 3 & 4.) In this rock, which is a fine-grained argillaceous limestone, a number of curious circular rings of coarse material are seen in section. A vertical section shows that these rings are produced into a tube, the total length of which is unknown. The external diameter of the rings varies in different specimens from 10 to 20 mm.; the length, so far as can be seen, is about 30mm. When the rock has become disintegrated by wet and frost, these tubes are found to be closed in at the base. A micro- scope-section shows them to be composed of small shell-fragments 1 Q. J. G.S. vol. xxxix (1883) pp. 178-74. 2H. A. Walford, Rep. Brit. Assoc. (Oxford) 1894, p. 304; ibid. (Ipswich) 1895, p. 415; and iid. (Liverpool) 1896, p. 356. 3 A. H. Green, ‘Geology of the Country round Banbury, &c.’ Mem. Geol. Surv. 1864, p. 32. Q. J. G8. No, 275. De 504 MR. M. ODLING ON THE [Oct. 1913, and oolitic grains arranged with their long axes parallel to the walls of the tube, so as to present a smooth surface internally ; the fragments all show evidence of having been rolled and coated, so as to form ooliths with one thin coat; typical ooliths also occur. Towards the base of the tubes the fragments are arranged in such a manner as still to present a smooth surface internally ; that is, the fragments forming the extreme base of the tube are arranged with their long axes at right-angles to those that form the sides. These tubes are very numerous in the Chipping-Norton Lime- stone of the Ardley section, and an apparently similar structure occurs in the Great Oolite of the Portland-Cement Works Quarry. It is impossible to state definitely how these tubes were formed ; but they bear a certain resemblance to the tubes constructed by such varieties of annelids as Yerebella and Sabella, so abundant on recent sea-shores. VY. CuemicaL Composition. The chemical examination of the rocks has in certain instances greatly facilitated the microscopic examination. In cases where the matrix is more or less opaque, it is impossible to distinguish between clay and amorphous carbonate of lime. The ‘ Cream- Cheese Bed,’ for instance, in thin section appears to be extremely marly; but the analysis has shown that 93:5 per cent. is composed of carbonates of calcium and magnesium. The proportion of magnesium carbonate was found to be so small (usually less than 1 per cent.), that after the first thirty analyses only the insoluble residue, iron, and alumina were calcu- lated; it was found that the iron and alumina, which were esti- mated together, were always in proportion to the amount of insoluble residue if it consisted of clay, but not if it consisted of quartz-grains. The most interesting results are obtained by con- sidering the insoluble residue, iron, and alumina together. When this was done, it was ascertained that the Cornbrash from two exposures, namely: Islip and the Portland-Cement Works, has approximately the same composition, containing the following per- centages of clay, iron, and alumina :-—— Clorsmlordyslay UMN Gy GEghadosson sedcuaeudadaacossodooe 8:53 Cornbrash, Portland-Cement Works ......... 1927 In the Forest Marble the sequence in different parts of the same quarry is so variable, that no result of any value could be expected, even from numerous analyses. The marly bands from the Upper Green-Hill Quarry, namely, C, and D,, yielded the following residue, iron and alumina, which was almost entirely clay. Per cent. (Opes SARE 51°24 - Vol. 69. ] BATHONIAN ROCKS OF THE OXFORD DISTRICT. 505 From the limestones the following percentages of insoluble residue, iron and alumina, were obtained :— TBIERNIXORRONIGI ce BoodacoabaccSanouseaecoe 6-2 Portland-Cement Works ............ 48 In the Great Oolite the results were more interesting, the Fossiliferous Cream-Cheese Bed having practically the same com- position in Gibraltar Quarry as in the Ardley section. Ardley. Gibraltar. Per cent. Per cent. Residue insoluble in hydrochloric acid... 1°33 | 1:39 Herrous carbonate ............eceseesacscenee 0°43 4:58 0:40 | 4:59 Ferrous oxide, alumina, and phosphates. 2°82 2°80 (OalciumarcanoOnaterweeecnneeeeaescneeeee seek 94:38 94:67 Magnesium carbonate ............ccsceceeees 0°39 0-41 _ The two Terebratula Beds in Gibraltar Quarry are found to have a very similar composition, the percentage of clay, iron, and alumina being as follows :—— First Terebratuta Bed ...... 14-94 Second Terebratula Bed... 16°64 The NMerinea Rock becomes slightly more marly when traced ‘from east to west, as the following results show (insoluble residue) :— Per cent. Gribralvarn ones ee tN Ge a et ely | 4-71 Portland-Cement Works ............ 5:04 INIROMey een SeaAnclan ae dese aor Aas 57d Since none of the beds below this are exposed in different ‘sections, it is not possible to institute any comparisons. In the Ardley section the compact limestones of the lower part of Block 2 vary in containing from 0 to 92 per cent. of calcium and mag- nesium carbonates. In Block 3 occur the least calcareous beds of the Great Oolite; the six beds from the Ardley section that have been analysed show the following percentages of insoluble residue, iron, and alumina; the residue in Bed 22 is entirely clay, ‘but in the other beds consists chiefly of quartz. Per cent. Per cent. Bed 227.002... 73:08 Bedi 22°62 Bed 23.....:... 25°32 iBedy 2G) eres: 5:59 15{c(ol PHS pen onen 16°67 Bedi Zines 20:04 In the Fullonian of Ardley we find the following percentages :— Bed 29 ica. 43:69 Bed 31 Fuller’s-Harth Rock ............... 16°88 Bed 30) ...... 41:52 Bed 34 Rhynchonella-Inoceramus Beds... 25°29 In the Nezran Beds the percentage of clay, etc. is very high, being anything between 58 and 91, except in the case of the Astarte Bed, where it is only 31:24. The green coloration appears ito be due to ferrous carbonate. Dae id | Bt 506 MR, M. ODLING ON THE [Oct. 1913, The Stonesfield Slates vary considerably in composition, the insoluble residue being chiefly quartz. The following table gives the percentage composition of the types examined :— Residue insoluble Iron and in hydrochloric acid. alumina. Sandy bed in Stonesfield ‘Slates’ ......... 46°75 1-47 Iaiine-parmaybneyel © SIRMES ” .ssooscesorcusso0ecosAunone ool 1:26 Medium-erained ‘slate’ .................-06- 19-73 4-96 Coarse-prained ‘slate’ ......................+ 12:14 3°60 Coarse-grained ‘slate’ enclosing pebble... 21-09 O75 Pebble from the above ........1.1.......... 11-94 4°84 Pebble from another specimen ............ 5:96 202 Vi. Prrrotoey. The microscopic examination of the Bathonian rocks has brought out to a marked degree the prominent part played by the Echino- dermata in the building of the Bathonian limestones ; except for a few minor bands, quartz is found only in the lower beds of the Great Oolite and in the Fullonian, and bedding is also only notice- able in these same rocks. The purer limestones may be divided into three main groups :— (1) In which the matrix consists for the most part of amorphous car- bonate of lime. (2) In which the matrix is entirely crystalline. (3) In which the matrix is partly recrystallized from an originally. amorphous form. Of those belonging to the first group, the most interesting are the Cream-Cheese Bed and the Fossiliferous Cream-Cheese Bed: the latter being practically uniform in character, both chemically and microscopically, from all the exposures. Of the seventy microscope-sections examined only four can be said to belong strictly to the second group; this includes the shelly equivalent of the Fossiliferous Cream-Cheese Bed of Gibraltar Quarry, also Beds 3 & 19 of the Ardley section. In the lower beds of the Great Oolite and in the Fullonian, angular quartz-grains are usually abundant; this is especially true of the Stonesfield Slates, where the ooliths are often formed round grains of quartz. In the coarse type of the Stonesfield Slates numerous rolled pebbles occur, as also irregular concretionary masses ; in section, these appear to consist of a rock somewhat similar to the fine- grained type. The irregular shape of some of these suggests that they were formed by contemporaneous rolling of the mud in the watercourses, and that they are not fragments of older beds. Quartz is abundant, and, in addition to the small shell-fragments, numerous small ooliths occur; fragments of echinoderms are by no. means uncommon, and in one section a small portion of a fish— tooth is seen. - Vol. 69. ] BATHONIAN ROCKS OF THE OXFORD DISTRICT. 507 Through the kindness of Dr, F. A. Bather, F.R.S., I was able to have sections cut of several echinoderm-spines, with the view of identifying those seen in the rock-sections ; but, since I was unable to obtain specimens from some of the commoner Bathonian genera, it was found impossible to identify them. Sections across different parts of the same spine show so different a structure, that no evi- ‘dential value can be attached to them, unless a very large number be examined. In all the ooliths found in the Bathonian rocks, the concentric layers are well shown, but no Girvanella structure has been seen ; those from the coarse type of the Stonesfield Slates are by far the largest, and usually show radial as well as concentric structure. They are generally formed round shell-fragments or small rolled fragments of rock, resembling the matrix in which they are embedded. VII. Corretarton, And Conprrrons or Deposition. The correlation of the exposures in the district are most readily seen by reference to the two subjoined tables (figs. 4 & 5, pp. 508 & 509); it therefore only remains to indicate their relation to other areas, together with the conditions prevailing in the Oxford district during their deposition. Lhe Chipping-Norton Series appears to be purely local, and to be represented only in the Chipping-Norton and Oxford districts, while the Neseran Beds seem to be equivalent to the acuminata zone: that is, just above the Fuller’s-Earth Rock of Dorset (8. 8. Buck- man, vn (tt.); on the north-east they keep approximately the same character, and are readily recognized as the Upper Estuarine Series in the Great Northern Railway cuttings north of Peterborough, where one band, the Astarte Limestone, is palzontologically and lithologically almost indistinguishable from that seen at Ardley. The Stonesfield Slates are known in the Cheltenham district, where between them and the Fuller’s-Harth Rock occurs a very fossiliferous band crowded with Ostrea and Rhynchonella, which Mr. Richardson designates * the Rhynchonella-concinna Bed. A similar bed occurs above the Nezran Beds round Chipping Norton, and at Ardley; in the Calvert Boring it rests almost directly on Chipping-Norton Limestone, and at Stonesfield on the Stonesfield Slates. The Fuller’s-Earth Rock, both of Somerset and of the Cottes- wolds, is characterized by Teloceras subcontractum, as are the Weatherstones and Shell Beds of Minchinhampton, and appears to come into line with Bed 31 at Ardley (L. Richardson, an litt. ). The whole group described as Upper Fullonian (Upper Beds of fig. 5, p. 509) can be paralleled with the Great Oolite Clay and Great Oolite Limestone resting on the Upper Estuarine Series north of Peterborough, where, however, Rhynchonelle are practically absent, although they are abundant in the same beds at Oundle. St or [e) yoogy JO aTvas is AUOJSAULT re =D Sy: [712100 5 o Ln) ot o co) ° a} 3 a a - SIO M S jooma,J “Iu quoted (asea) Burying puryii0og AszenO Aaqpry p10jXO IH w9019 : MAO fo sq ao} TANO ! S007 9=0 nj q=/9= | (3Ss8M) Arzeng AazenO Arend AsxenQ 12M. IIH weery IeYeIqry uopelg enosoqueyy y-sno10queyy ‘I1QUD]T Walog pun ysouqu.log fo a.nysptofag we saimsodua pndraws d ayy fo worjnpat.coo ayy Huynusnpjr 8w0r998 1092}.104 —"f “OL Great Oolite Fig. 5.—-Vertical sections illustrating the correlation of the principal exposures in Oxfordshire of Great Oolite and Fullonian. Gibraltar Green Hill Cement Ardley Cream Cheese Crean Cleese 4] Fossiliferous Tossiliferous lock 1 ream Cheese: > > l Block 2 lock Great Oolite > > I ‘Roach’ Bed Nerinuva j Neriinea } Rock. Rock Nerinwu | Rock > 2 ee) = ee Base of Base of 2 Quarry Quarry — Base of Quarry Scale of Feet Faurllers Earth Rock thynchonellie t Jnoceramus } Beds Gn = uu (e) Tiel cleat Neceran ) Upper Beds Astarte Linwestone Sands Chipping Norton Limestone Sharp’s Hill Quarry Quarry Works Cutting Hook Norton - - =- -- “SOIL Rhyn- chonella Beds Astarte Limestone} ; eon | Birds i | |} Rock | f | Northampton | Stockey Bank Stonesfieid SOIL Rhyn- chonella 1 Beds 1 Sfones- Field Slate Series Chipping Norton Limestone Necran ae | Clypeus Grit U per Beds 510 MR. M. ODLING ON THE [Oct. 1913, The beds in the Great Oolite cannot be correlated in detail; but Mr. Richardson considers that Bed 21 of Ardley (the Roach Bed) may represent the Dagham Stone of the White Limestone division in the neighbourhood of Cirencester. North of Peterborough these beds do not appear to me to be represented, the Cornbrash resting directly on the so-called ‘ Great- ‘Oolite’ clays. Except in two places (see p. 502), the Bradford-Clay _ facies does not seem to be developed; while, but for their very small thickness, the Forest Marble and Cornbrash are apparently quite normal. In order to understand the conditions prevailing during the deposition of the Bathonian rocks in the Oxford district, it is necessary to consider what conditions prevailed during previous times. At Fawler there is evidence that a barrier was being formed a short distance away to the north; the rising of this barrier caused the Middle, and more especially the Upper, Lias to be very thinly deposited, so much so that in a band only 3 inches thick, among others, the following ammonites occur :—Harpoceras ef. faleiferum, Dactylioceras commune, and Hildoceras bifrons. Above this band comes about 12 feet of unfossiliferous clay, followed by the Upper Trigonia Grit and Clypeus Grit, which form the Parkinsont Beds of the Inferior Oolite, this zone over- lapping all the lower zones. During the same time, north of this barrier, sands, for the most part unfossiliferous, were being deposited, which have usually been called the ‘ Northampton Sands,’ although in reality they are not equivalent to the true Northampton Sands, which are of earlier date, but are in part homologous with the Clypeus Grits, as Mr. Walford has shown.’ These North Oxfordshire Northampton Sands (to use the general term, since no distinctive name has been assigned to them) are well exposed near Westcott Barton and at the tunnel-mouth near Fritwell in the Ardley section. South of this there is no definite record of them; they certainly do not occur in the Oxford City- Brewery Well, and it is extremely doubtful whether they occur as far south as Bicester, although the well-section at Gowell Farm and Upper Arncot suggests their presence.* We see, then, that a ridge lay north of Fawler and Stones- field, curving round to the south of Fritwell, and possibly passing under Bicester ; north of this ridge bands of sand were deposited, while on the south the Clypeus Grits were deposited, the latter probably thinning-out towards Stonesfield and not being laid down as far east as Oxford.° 1 “On the Relation of the so-called ‘‘ Northampton Sand ” of North Oxon to the Clypeus Grit’ Q.J.G.S. vol. xxxix (1883) p. 224. 2 R. H. Tiddeman, ‘ Water-Supply of Oxfordshire’ Mem. Geol. Surv. 1910, pp. 26, 29, 67. 3 The absence of Newran Beds in the Calvert Boring suggests that the boring lies on this ridge, which continued to assert itself certainly until late Stonesfield-Slate times. - Vol. 69. ] BATHONIAN ROCKS OF THE OXFORD DISTRICT. 511 On the Clypeus Grits and Northampton Sands le a series of beds, chiefly calcareous, forming the Chipping-Norton Limestone, which have been exposed round Chipping Norton, at Fawler, Stonesfield, and in the Ardley section; and they probably also occur under Oxford. This is followed by the Nezran Beds, predo- minantly green clays containing wood as well as numerous dwarfed oysters (Ostrea sowerbyi), and resembling the oyster-banks of the Lower Fullonian near the Fleet, Weymouth. Upon these south of the ridge were laid the Stonesfield-Slate beds, which probably do not extend far east, north, or south of Stonesfield, nothing that resembles them being recorded in any of the well-sections. The coarse oolitic nature of some of the beds, together with the rolled fragments, suggests shallow water, and possibly the ridge on the north continued to rise, thus cutting off mud from that direction ; while proximity to land is suggested by the very large percentage of angular quartz-grains and the perfect preservation of delicate land-plants, as also by the abundance of insect-remains. The fact that the teeth of Pycnodont fishes are found embedded in the rock in their natural relative positions shows that the current cannot have been strong, although deposition must have been rapid. Unfortunately, nothing is known of the Stonesfield Slates in this district except from Stonesfield; and thus it is impossible to trace their thinning-out, or to arrive at any conclusion as to where the quartz came from. ‘The beds seem to have been laid down in shallow water not far from land, while the abundance of sand and plant-remains suggests that the river which brought down the material probably entered the sea not far off. The Rhynchonella-Inoceranus Beds (Beds 33-35 of the Ardley section) seem to have been deposited right over this ridge, and to have been but slightly influenced by it. The thinning of the upper beds of the Great Oolite towards the north-east is suggestive of a land-surface in that direction, an inference which is further borne out by the apparent absence of these beds north of Peterborough. Throughout the Great Oolite Period in the Oxford district, the beds were apparently deposited in water that was shallow, but still sufficiently deep to prevent them from accumulating under the influence of shifting currents. The alternations of horizontal bedding with marked false bedding in the Forest Marble seem to suggest violent oscillations of the currents, possibly due to periodic changes in the level of the sea- floor; while the thinning of the Cornbrash towards the suggested ‘position of the ridge and its entire absence at Calvert, imply that, for a time, the folding along the ridge reasserted itself. It should be noticed that Mr. Buckman considers the absence of Cornbrash in the Calvert boring to be due to the denudation of an anticlinal fold previous to the faulting (see Q. J.G.S. vol. xix, 1913, p. 341). Personally, I consider that thinning-out of the Cornbrash (owing to non-deposition on the axis of the fold), followed by subsequent faulting, is a simpler explanation. 512 MR. M. ODLING ON THE [Oct. 1913, EXPLANATION OF PLATES XLVII & XLVIII. Puare XLVIL. Fig. 1. Exposure in Upper Green-Hill Quarry, eastern end, 2. Exposure in Lower Green-Hill Quarry. Puate XLVILI. Fig. 1. Cornbrash from Hanborough Quarry. near the railway-station; 16. Two large ooliths, probably derived, occur near the top; the rock consists, for the greater part, of small shell- and echinoderm-frag- ments in a somewhat marly matrix; echinoderm-fragments are most abundant towards the bottom and left-hand edges. 2. Stonesfield Slate enclosing a pebble; x 16. The ‘slate’ consists of small shell-fragments and quartz-grains, together with numerous ooliths and one large echinoderm-fragment near the top towards the right; the pebble consists of small shell-fragments and abundant quartz-grains, without any ooliths. 3. Transverse section of the annelid-tube described on pp. 503 & 504; x 44. This shows the concentric arrangement of the particles ; the irregularly-arranged material on the left-hand half of the central portion has evidently fallen in. 4, Longitudinal section of the above, showing the arrangement of the fragments parallel with the length of the tube. 44. Discussion. The Secrurary read the following letter, received from Mr. 8. 8. Buckman :— ‘The abstract of the paper on the Bathonian rocks of the Oxford district appears to indicate that the Author has accomplished an important piece of work. The geology of that district is little known in detail, except from a paper by Mr. E. A. Walford read before, but unfortunately not published by, the Society '—a paper written before the cuttings on the new railway gave a further insight into the sequence, which is a great advantage to present-day investigators. ‘The present Author seems to have been able to confirm Mr. Walford’s sequence. ‘When the Author states tliat ‘‘ although no definite zones can be formulated, the different horizons are readily recognizable by their assemblage of fossils,” he seems to be under some misapprehension as to a zone. ‘The different assemblages of fossils are the local zones: their correlation with the zonai system of the similar strata on the south-west should present no difficulty, and, if stated, would give to the paper greater value and a wider interest. Besides, ammonites from these strata have been obtained by other investigators, which would yield further evidence for fixing zones. ‘A particular interest in the strata of this district is the position of the Neran Beds, already ascertained from Mr. Walford’s researches. They link up the marine Fullers’ Earth strata of the south-west with the Upper Estuarine deposits of Yorkshire, and thus enable the date to be fixed for the Yorkshire beds. ‘The Author’s use of the term ‘ Concinna Beds’ is inadvisable. Rhyncho- nella concinna is a species of the Cornbrash. Various more or less concinna- like Lhynchonelle are found in earlier rocks, but to give them the name of the Cornbrash species is misleading. here is a somewhat large inconstantiform Riynchonella which occurs in, and is characteristic of, certain Fullers’ Earth deposits of the Ardley Cutting. So far as I know, it does not occur in other districts; but it should not be calied Lh. concinna.’ 1 [This paper, under the title of ‘Some New Oolitic Strata in North Oxford— shire,’ was afterwards privately printed: Buckingham, 1906. ] Quart. Journ. Geo. Soc. Vor. LXIX, Pc. XLVII. - Fig.l. UPPER GREEN HILL QUARRY, EASTERN END. Subsoil & rubbly limestones | very fossiliferous. = a z ie. ia TINTERMEDIA fimestone Ss Line of rolled nodules. Sandy marl, (A) ui =) a a panuizuog ~<—— “~ Nee, ‘ALTO IOpNog Aopaq. spoq © » 'T ATarqord INS 8SENSSSE TAN WK K S KSEE 3 \ E ; IN i NS STD \ “kvTO deptnog uo a SS S_/ (¢)Wovod posivy, Ssh Sas SS RS Be ms SSE mojaq J SS) RNS BESS Pa ueqiqd josO panulzuog yryos yyI0g uAmuo Fy SSD JO W}ION (‘{1ny » pun ajw v pnogn=yjbuary) *a.don Utajgsem-yyuow ay) 02 laspang £0 78M09 Ulagspa-YWNos ay) WOLf U027909V—"G “STL s Vol. 69.] THE GEOLOGY OF BARDSEY ISLAND. 521 (c) The South-Hastern Coast. (Part of fig. 2, p. 520.) This shore consists mainly of the siliceous slates with their usual quota of grit- and quartzite-bands, already described as occurring on the south-western coast; but diabases also occur, in two long strips separated by a slaty crush-conglomerate that contains abun- dant quartzite aud rare lenticles of limestone. These diabases undoubtedly belong to the same group as those seen about Maen Du. They have often a sheared aspect, and pass into ‘ schalsteins’; parts of them look pillowy and may be lavas, but some of the masses are intrusive. They contain bands and lenticles of chert-like sediment, apparently folded intensely, and these seem to be contact-altered rocks or adinoles. Some of the igneous rocks distinctly cut across the bedding, and form lenticular sills. Farther north-west, in the bay of Henllwyn, a large mass of pillowy diabase or spilite, showing remains of vesicular and variolitic structure, occurs below high-water mark, and there may be more lenticles at that locality; but the rocks are obscured by thick growths of Fucus. Grit, slate, and some calcareous sand- stone are also in evidence, the whole being broken up into a crush-breccia. From the shore-sections just described, it will be apparent that, despite a fairly constant direction of dip, there is much repetition of the strata, evidently the result of overfolding and overthrusting. The following rock-groups are recognizable, and seem to occur in the order shown below :— (vii) Cataclastic grits and slates, with occasional limestone. (vi) Variolite and diabase, partly as intrusive sills and partly as pillow-lava (spilite). (vy) Gritty slates and fine-grained sandstones, usually showing regular cleavage and containing thin flaggy quartzite and grit-bands. (iv) Limestone-and-quartzite group: that is, slates with included thick beds and lenticles of quartzite and limestone. (iii) Cataclastic grits and slates. [Granite-sill intruded usually at about this horizon. | (ii) Sandy slates, showing regular cleavage. () Sandy slates, with quartzite-bands. (d) Mynydd Enlh. A thrust-plane hading westwards can be followed, as already stated (p. 518), from Bau y Nant in a southerly direction. It can be traced along a bracken-clad hollow on the western slope, and divides the hill structurally into two portions. It reaches the shore near the harbour of Henllwyn, and may be continued across the bay as one of the thrusts that traverse the south of the island with a west-south-westerly course. The western, or overthrusting, limb consists of cataclastic green slates, with one or more purple zones; enclosing many small phacoids of grit and occasional larger lenticles of flagzy grit, quartzite, and limestone. The cleavage, usually phacoidal, dips at 30° to 40° west 2u 2 522 DR. C. A. MATLEY ON THE [Oct. 1913, to north-west. There is a small quarry in these slates, about 50 yards south-east of the school, exposing a purple igneous rock which microscopic examination shows to be a fine-grained de- composed variohte. It underlies a tufaceous shale containing pebbles of the same rock with chert and some sediment, and so there is no doubt that the igneous rock in this case is a lava and not a sill. On the east the beds below the thrust-plane dip at higher angles, usually from 60° to 90°, and the dip is generally a reversed one. A conspicuous outcrop of quartzite about 8 feet thick helps us to elucidate the structure here. On the crest, south of the summit, at about 300 feet O.D., the quartzite stands up as a prominent rock, and can be followed along the hill-slope as a sigmoidal fold, as shown in fig. 4. Though broken by a fault, this bed can be traced Fig. 4.—Sigmoidal fold on the ridge of Mynydd Enlh, a the 300-foot contowr, looking north. poor Q [Q = Quartzite. L= Limestone. th.= thrust-plane.] northwards for a distance of about 400 yards as a group of thick lenticles which lie between the crest and the sole of the thrust. Still farther north several more large lenticles or ‘ quartz-knobs’ are to be seen, one of which is represented in Pl. XLIX, fig. 2. They may be portions of the same bed. Two other fine examples of large isolated lenticular masses are perched, one near the other, on the steep slope above Ogof Morlas, and dip east-north-eastwards at 40° to 50°. One is of quartzite, the other of limestone. On the bare northern slopes of the hill cataclastic gritty slates dip steeply, though with many minor contortions and small over- folds, below the two great lenticles just mentioned. They contain the usual broken bands of grit and quartzite; while a zone of thin, flagey, quartzose grits and lenticles of a fine clastic breccia (or angular grit) make their appearance in places. At the northern ra Vol. 69. | GEOLOGY OF BARDSEY ISLAND. 523 summit, in the core of an overfold, a highly-vesicular, rotten, basic igneous rock, presumbly a pillow-lava, occurs in association with limestone and quartzite. Not far away, near the 505-5-foot bench-mark, is a dyke-like mass of diabase, some 25 to 30 feet wide, referred to by Dr. Flett in the Appendix (p. 530). The adjacent slates show contact-alteration. The steep eastern face of Mynydd Enlli has not been examined by me, but the rocks are seen from the sea to be mainly cataclastic slates frequently containing masses of quartzite and limestone. Towards sea-level the structural planes dip westwards at moderate angles. On the shore at Bau Felen occur some ferruginous ochreous rocks which may be basalts, but I was unable to examine them. Farther south the coast is occupied by great crush-con- glomerates of quartzite and limestone in a slaty matrix, which can be conveniently studied on the headland of Pen Cristin. (e) The Crush-Conglomerates of Pen Cristin. Between Henllwyn and Pen Cristin some stages in the process of disruption which has given rise to the formation of these crush- conglomerates can be Fig. 5.—Overfolding in quartzite-bands traced. ‘The shore-sec- interbedded with slates; cliff west of tion here is remarkably Pen Cristin. like, and is as instruc- tive as, that exposed on the shores of Cemaes Bay (Anglesey).’ North- east of the harbour of Henllwyn the quartzite and limestone group is well exposed, as thick beds contorted, folded, sheared, and broken into lenticles, lying among slates with irregular and contorted cleavage. Farther east come slates with numerous broken bands and long lenti- cles of quartzite and occasional lenticles of limestone, which ex- hibit overfolding (fig. 5). [The longest band shown is some 20 feet in length.] At Pen Cristin they give place to more thoroughly cataclastic strata, consisting of a slaty matrix full * Described by me in Q.J.G.S. vol. lv (1899) pp. 661-65. As the lime- stones and quartzites of Bardsey are precisely like those of Northern Anglesey, no lithological description is given of them in the present paper. 524 DR. C. A. MATLEY ON THE [Oct. 1913, of inclusions of grit, quartzite, and limestone, sometimes rudely phacoidal, sometimes irregular, and often more or less rounded, and of all sizes from large ‘boulders’ to tiny ‘pebbles’ (fig. 6, below). Yet, even in these shattered strata, traces of overfolding can be seen, as fragments of the same limestone-band recur again and again at various heights and at various places in the cliffs. Cataclasis of the strata is admittedly due to the crumpling effect of compression acting differentially on hard, brittle, and less yielding beds (the grits and limestones) when interbedded with softer and more extensible slates, with the result that the former have broken up and the latter have flowed round the fragments. Fig. 6.—‘ Orush-conglomerate’ in the cliff at Pen Cristin. C. A. M. photo. In this locality the disruption seems to have acted along the septa of small overfolds or buckles in steeply dipping beds.* Fig. 1 of Pl. XLIX represents a portion of a cliff—not on Bardsey itself, but on the adjacent mainland near St. Mary’s Well, south-west of Aberdaron. It has been introduced to show the passing of interbedded bands into a crush-conglomerate, and also the deformation of a massive bed of quartzite into two wedges. 1 See G. Barrow, ‘On Buckled Folding’ Geol. Mag. dec. 5, vol. ix (1912) p. 018. Vol. 60.] GEOLOGY OF BARDSEY ISLAND. 525 LY. Post-Movementr [nrrusions. Three olivine-dolerite dykes with a north-westerly to south- easterly trend have been noted in the course of the mapping. They are quite uncrushed, and occupy fissures which cut across the structures of the surrounding strata. One of them, some 40 feet or more wide, has been excavated by the sea to form the little harbour at Cafn Enlli. Another but narrower dyke is seen in the cliff-fissure of Ogof y Gaseg: it splits into two branches, both of which die out before reaching the top of the cliff. The third dyke, 9 feet wide, occupies the fissure-indentation in the coast at Ogof Hir. In addition, I have detected two small bosses of similar dolerite on the western slope of Mynydd Enlli. On the shore at Briw Gerig, east of Mynydd Enlli, as seen from a boat, are many blocks of a basaltic rock which may be a thick dolerite-dyke; on the other hand, it may be one of the older diabases. V. SrRAlIGRAPHICAL SUMMARY. From the foregoing description it will be seen that the rocks of Bardsey have been shattered by earth-movements, which have acted from directions between north and west. So great is the shattering that almost everywhere the harder bands, whether thick or thin, that were interbedded in the slates have been torn to pieces, and lie as detached blocks and lenticles in the softer slaty strata. The general tectonic arrangement, though to a great extent masked by this local shattering, has been shown to consist of a number of broken overfolds, which are accompanied by thrusts. The rocks themselves are mainly gritty schistose slates, with many thin and some thick bands of grit, quartzite, and limestone. They contain an horizon of yariolitic lava and tufaceous shale which indicates that a volcanic episode occurred during their formation. Except in this last-mentioned zone, the bedded rocks seem to be ordinary sediments ; some pyroclastic fragments probably occur in them, but they are not conspicuously present. There are, however, sills of albite-diabase folded in with the sedimentary strata, as also one or more sills of a crushed granite. From the nature of the brecciation and the comparatively small amount of mineral change which the beds have undergone, it is inferred that the load of superincumbent rock at the time of the principal earth-movements was not great. In order to ascertain the age of the beds, we must go to the main- land, where there is evidence that rocks precisely similar to those in Bardsey had been altered to their present condition and denuded before Lower Arenig times, as many fragments of the schistose slates and grits, in the condition of sericitic phyllite, quartz- granulite, etc., occur in a Lower Arenig breccia on the promontory about % miles north-east of Bardsey. From a consideration of the 1 C. A. Matley, ‘The Arenig Rocks near Aberdaron’ Geol. Mag. dee. 4, vol. ix (1902) p. 122. 526 DR. C. A. MATLEY ON THE [ Oct. 1913, known Cambrian rocks of North Wales it is clear that the Bardsey and Lleyn rocks must be of pre-Cambrian date. The intrusive diabase and granite-sills may be also of pre-Cambrian age. The sedimentary rocks of Bardsey can be correlated with the lower beds of the Llanbadrig Series of Northern Anglesey and with their equivalents, the Llanfair-y’nghornwy Beds of North-Western Anglesey. In the latter area there is also, as in Bardsey, an intrusion of granite which has undergone much crushing, and it may, perhaps, be correlated with the Bardsey granite. As regards the post-movement dolerite-dykes, similar dykes can be seen in large numbers in the pre-Cambrian strip of the neigh- bouring mainland, where I have mapped about 125 of them. They are most probably of Tertiary age, as already suggested by Mr. HE. Greenly for dykes of the same composition and with similar trend in Anglesey,’ and Dr. Flett writes to me concerning a rock-slice from one of the Bardsey dykes [9091],* that it is an ‘ ophitic olivine-dolerite with fresh basic felspar, extraordinarily like some Tertiary dolerite-dykes of the West of Scotland,’ VI. GractoLoey. In the 2nd edition of his North Wales Memoir Ramsay mentioned the Glacial drift of Bardsey, and observed that the island “has been moulded by ice...., but the mammillated roches moutonnées have since been roughened by the weather.’ (Op. cit. p. 212.) The only other reference to the glaciation is in Dr. Jehu’s paper of 1909, where he remarks that ‘the island as a whole may be regarded as an example of the phenomenon known as “crag and tail,” the crag facing the north-east, from which direction the ice-sheet came.’ (Op. cit. p. 29.) Among the boulders and pebbles recorded by him from the boulder-clay of the island may be mentioned Chalk-flints, Ailsa Craig microgranite, Dalbeattie granite, picrite, Carboniferous Lime- stone, and shell-fragments. The result of my own investigation of the drift-phenomena of the Island is given below. Glacial drift, in the form of boulder-clay, covers most of the ground between Mynydd Enlli and the western coast, the mountain itself being almost free from drift, though its. rocks are frequently moutonnées. ‘The drift-covered area is given over to agriculture. In the south of the island the drift is patchy and very thin. Ice-worn surfaces are common, though few of them have retained their scratches. I found striz, however, at 1 “On the Age of the Later Dykes of Anglesey’ Geol. Mag. dec. 4, vol. vii (1900) pp. 160-64. 2 The numbers in square brackets here and in the Appendix are the numbers of the rock-slices in the Museum of Practical Geology, Jermyn Street, cut from material handed over to that Museum from my collection. s Vol. 69.] GEOLOGY OF BARDSEY ISLAND. 527 five localities,’ and they all indicated movement of the ice to the east of south, not to the south-west as previously supposed. The suggestion quoted above that Mynydd Enlli affords an example of “crag-and-tail’ structure falls, therefore, to the ground; in fact, the roches moutonnées on its eastern slopes are worn parallel to the trend of the ridge and not across it. As Dr. Jehu had already investigated the sources of the Bardsey boulders, I contented myself with collecting a few specimens from the boulder-clay of Porth Solfach and neighbourhood, and sent them to my friend Mr. E. Greenly for comparison with Anglesey rocks and boulders, as it seemed highly probable that the ice-sheet that invaded Bardsey had previously passed over Anglesey. His determinations are interesting, as they enable the movement of the ice-sheet to be defined very closely. Two of the pebbles are red granites of typical ‘Mona’ type, while a third of fine-grained granite is also a Mona granite. An augen-gneiss pebble may have been derived from the Anglesey gneisses, but Mr. Greenly is more inclined to regard it as derived from the Scottish Highlands. Other Anglesey rocks identified are Ordovician grit and slate, and white cherty shale from the top of the Carboniferous Limestone. Other specimens, including Chalk-flints, occur as boulders in Anglesey, and only two specimens (a purple rhyolitic felsite and a yellowish grit) are unknown to him. Now, the Mona granite is practically confined to a belt in Central Anglesey which has a south-westerly trend corresponding with the general trend of the ice-sheet in that region, and Ordovician grits and slates lie on the flank of the granite, while Carboniferous Limestone lies on the north-west. The portion of the Irish-Sea glacier that invaded Bardsey must, therefore, have passed over Anglesey to the west of Red Wharf Bay. The course of the ice-sheet across Anglesey was in a south-westerly direction ; and this course is now shown to have been deflected in Carnarvon Bay to a direction east of south, a deflection which seems to have been caused by pressure from the ice that radiated from the east of Ireland. It was previously known that Irish ice had forced the Irish-Sea ice into South Wales, across Cardigan Bay into North Pembrokeshire ;? and it is of interest now to find that the pressure has also left its traces in this little westerly outpost of North Wales. 1 The localities are:—The coast north of Mynydd Enlli; Hen-dy; Porth Solfach, near the granite; near Trwyn Dihirid; and the coast east of the lighthouse. 2 See T. J. Jehu, ‘ The Glacial Deposits of Northern Pembrokeshire’ Trans. Roy. Soc. Edin. vol. xli, pt. 1 (1904) p. 53, and previous literature quoted therein. Asa contribution of my own (‘On the Geology of Part of North- East Pembrokeshire’ Proc. Birm. Nat. Hist. & Phil. Soc. vol. x, pt. 2, 1897, pp- 92-101) was inadvertently overlooked in that paper, I hope that I may be excused for mentioning that I had previously proved the former presence of Trish-Sea ice in the north-east of that county. [Attention is also invited to the Discussion, pp. 532-83, both as regards the former presence of Irish-Sea ice in Merionethshire, and as to the cause of the deflection of that ice into Cardigan Bay. | 528 DR. J. 8S. FLETT ON THE [Oct. 1913, VII. Tus Posr-Gractat Ratsep Beacu (?). The isthmus between Porth Solfach and Henllwyn forms the lowest part of the island, with a level about 18 to 20 feet above Ordnance datum. The low cliffs on each side are excavated in boulder-clay, on which lies at several places a shingle resembling a thin beach-deposit. I also found sand containing marine shells in one of the fields about here. It seems not unlikely, therefore, that we have at this spot a relic of the post-Glacial 25-foot beach so well-known on the east coast of Ireland; but the evidence is, to my mind, not strong, and I should like to have confirmatory evidence of a similar beach on the neighbouring mainland of North Wales before definitely adopting this explanation. One would expect, for instance, that when the sea was at raised-beach level the scour of the tides between the two islands into which Bardsey would have been divided would have swept out the boulder-clay. One has also to consider the possibility that the shingle and sand may in recent ‘times have been cast over the isthmus during storms, or even that the shingle may have been spread artificially along shore cart-tracks now cut into by coast-erosion. Mr. Fearnsides has recently recognized some features on the coast east of Criccieth, which suggest to him a post-Glacial rock- platform about 10 feet above tide-level.’ This level corresponds fairly well with that of the Bardsey platform, so that further work in the Lleyn may establish a post-Glacial raised beach in Bardsey beyond reasonable doubt. In conclusion, I wish to express my warmest thanks to Dr. J. S. Flett for undertaking the examination of the rocks and for con- tributing an Appendix on the Petrography, and to Mr. Greenly for his comparison of the Bardsey drift-pebbles with Anglesey rocks and boulders. My best thanks are also due to Mr. Herbert H. Thomas, Sec.G.8., for supervising the preparation of the colour- printed map, and to the Assistant Secretary for his care in seeing the paper through the press during my absence in India. VIII. Appenpix on THE Petrroerapuy. [J.8. F.] (1) The Granites. The granite that forms the sills or veins on Bardsey Island is pale, usually greyish green from the abundance of chlorite. It is neither coarsely crystalline nor porphyritic, and all the specimens examined have a crushed or broken appearance, although there is nothing like a well-developed or regular foliation. Occasionally, the granite is so much shattered, with broken felspar-crystals lying in a dark-green chloritic matrix, that it becomes very similar in appearance to a crushed felspathic grit [9090, Porth Solfach]. 1 «The Tremadoe Slates & Associated Rocks of South-East Carnarvonshire’ Q.J.G.S. vol. lxvi (1910) p. 184. Vol. 69.] PETROGRAPHY OF BARDSEY ISLAND, 529 The various specimens selected for slicing are so like one another in composition and structure, that there is no difficulty in believing that they are all of closely allied origin; they may, in fact, represent one sill repeated by folding. Both muscovite and biotite are present in the slides, the latter being the more abundant, though it is practically always replaced by chlorite. Part of the muscovite is primary, but there is also secondary white mica developed from the felspar. The rock has contained much orthoclase, though this is seldom in good preserva- tion, being mostly converted into ‘shimmer-aggregates’ of sericite. A fresh polysynthetic felspar is also common, and proves on being tested always to be albite. Zircon, iron-ores, and sphene are the accessories, and, in addition to sericite and chlorite. some- times epidote, rutile, imonite, and carbonates occur as secondary minerals. The structure is cataclastic in a high degree, the quartz being crushed, the felspar broken and sericitized, and the mica drawn out into irregular wisps and streaks. ‘Some of the slides show a good deal of fine granulitic material, consisting of quartz, felspar, and white mica. The granitic structure is often sufficiently clear how- ever, especially at Ogof Hir [9293] and Bau y Rhigol [9288]. Towards the margins of the sills there is a development of a porphyritic facies, which has an abundant microcrystalline or felsitic matrix with phenocrysts of original muscovite, in addition to quartz and felspar [9289, north-western corner of the island ; 9291, Ogof Hir]. The question arises whether the granite has any connexion with the pillow-lavas and diabases. In several parts of Britain (Tayvallich,* Porthallow *) granitic rocks occur intrusive into pillow- lavas, in such a way as to suggest that they are of kindred origin. These granites are generally rich in soda, and contain much albite. The Bardsey granite has a fair amount of albite, though not so much as the ‘soda-granite’ of Porthallow. It seems quite likely, although in the circumstances it cannot be definitely proved, that in Bardsey Island also the pillow-lava eruptions terminated by the intrusion of an acid magma, now represented by the Bardsey granite. (2) The Pillow-Lavas and their Tuffs. The rocks of this group are much altered by decomposition and by pressure. Their felspars are replaced by sericite and carbonates ; their femic minerals by carbonates and chlorite ; their iron-ores by leucoxene and limonite. Little of their original structure remains, except traces of phenocrysts and of amygdaloidal cavities filled with calcite and chlorite. Crushing has gone so far as to produce a well- marked cleavage, and in some cases an irregular schistosity. Many 1 «The Geology of Knapdale, Jura, & North Kintyre’ Mem. Geol. Surv. Scot. 1911, p. 98. 2 ) woes NUWISe ST + et dures 1S In. SSeS e ssh Hai + 1 Sy, MOTZOUL is Y surey tn furl lesp HS) pice eget Clete eel eaol gas ey: Ry Sear ME iS (e) Oly 01u0q ray Ves Is y e iS % viuaso is efue7—3 Y S % g I C9’os [VUOZIIOY soumty by qours=4y OOSF BTV TVoIVIEA ‘{ VY OUl] SUOTL MOYdIg - 7 Fy SE0z | Ty? J Jf Ipesey'T Jp j7? smeid einy (s IQVIVIN AAVT pue AVMTIva VANVON AHL UWdIAAjoq JOIST, 9} Jo Weg jo de. -YI}94S ]eIsojoay 21naS j Sule BIuUUaMy ES vy * Vol. 69.] METAMORPHOSED SEDIMENTS IN BRITISH EAST AFRICA, 537. are not rare. A few irregular grains of calcite, presenting the appearance of an original mineral, are noteworthy. With a view to the study of the arenaceous sediments, if they may be so termed, intercalated between the beds of marble, a thin section has been prepared of a rock which is almost entirely a binary compound of quartz and felspar. Its thickness was some 18 inches. The calc-rocks between which it was found were of different facies: the upper coarse, the lower much finer in grain. The rocks of the section were decomposed, and the section overgrown, but my impressions in the field were that the gneiss did not represent a sill. Most of the felspar is unstriped, but the rock contains a little acid plagioclase and microcline. Some secondary white mica, derived from felspar, and a few original flakes of a reddish-brown biotite, also occur. As appears to be usuai in these rocks, the microcline is late in consolidation, and has corroded the other minerals. In this rock also the tendency of the quartz to form elongated vermicular phacoids and extremely irregular grains, with coral-like apophyses, is worthy of note. This structure appears to be characteristic of certain rocks of this series. The same peculiarity is more marked in another example, also a binary compound of quartz and felspar, and found between marble beds in the stream known to the Masai as II Bisil, south of the drainage-basin of the Turoka. The rock consists of an aggregate of quartz and felspar, with a few flakes of biotite and muscovite. The foliation is distinct, the quartz forms long grains which usually are transversely cracked, and suggest that the rock was originally a coarse grit- or pebble-bed. In some instances, the quartz-grains have been clearly formed before the microcline, the erystals of which abut against its surface. An acid plagioclase is an important constituent. The biotite has a marked absorption : C is brownish red, as in some kinzigites, and A is of a pale straw- colour. Intercalated between marble beds from the same locality (II Bisil) was collected another rock, having some relation with the kinzi- gites and with the last-described rock. It is composed of pink garnets, lapped about by a red-brown mica, in a base of quartz and water-clear felspar, the former predominating. ‘The angles of extinction of the latter are small, but much of the felspar is un- twinned. The quartz shows the elongated blunt-ended lenticles noticed before. Small granules of zircon also occur, and one or two of a mineral which appears to be the kyanite of other slides. Similar rocks, having affinities with the kinzigites, were found in the stream-bed first mentioned, and about 300 yards from the recorded section. The rock, a garnet-biotite-gneiss, contains some quantity of magnetite and ilmenite, the former being the commoner. The biotite is of the usual straw-coloured variety customary in these rocks, and quartz preponderates over felspar, the greater part of which is unstriped. Thereis no microcline. Zircon and apatile 538 METAMORPHOSED SEDIMENTS IN BRITISH FAST AFRICA. [ Dec. 1913. are rare accessory minerals, and’ the rock contains also occasional grains of dirty epidote or sphene. A rock with the same associates and from the same stream consists principally of scapolite, diopside, and brownish-red garnet with accessory calcite, quartz, hornblende, plagioclase, sphene, apatite, and zircon. The water-clear plagioclase belongs to the acid end of the series. The apparently corrosive action of the quartz and plagioclase on the hornblende is noteworthy, the last- named mineral giving finger-shaped cross-sections, which, it is of interest to see, are peripherally converted into glaucophane. This mineral has a pleochroism varying from yellowish-brown to ultramarine. From.the bed of an important tributary to the Turoka, entering below the streams above-mentioned, comes a compact gneiss con- taining epidote in quantity. The mineral forms irregular grains, and is occasionally idiomorphic. ‘The scheme of pleochroism is, A, colourless, or very pale yellow; B, colourless; C, pale greenish- yellow. Sphene is a common accessory mineral, and is earlier in formation than the epidote. Quartz is abundant, and forms large grains containing many inclusions; apatite and zircon are rare. The acid plagioclase is often zoned, microcline is common, aud corrodes the earlier plagioclase. Three slides of kyanite-schist were cut from specimens re- presenting three successive beds only a few inches apart, situated on the bank of one of the headwater streams of the Turoka. The uppermost is a kyanite-muscovite-biotite-quartz-schist with subsidiary microcline or microperthite. Quartz greatly pre- dominates, the grains are elongated parallel to the predominant foliation, one grain polarizing over large and irregular areas, giving the impression of the slow rupture of viscous substance. The underlying rock has a rather confused crystallization : micro- perthite is conspicuous, but there is no simply-twinned plagioclase. The quartz is dusty and full of inclusions, and the kyanite forms large irregular plates; a red-brown mica is conspicuous. White mica and zircon are accessory minerals. : In the third section, muscovite and biotite are subordinate, the felspar has an irregular wavy extinction, suggesting very strongly fine microperthite; and, as before, there is no simple plagioclase. Locally, the kyanite is altering into a fine aggregate of hydrous white mica. Elsewhere in the same stream-bed, kyanite-gneisses, still richer in the specifie mineral, occur. A thin section of one shows the rock to consist almost entirely of kyanite and quartz, a few crystals of zircon and flakes of white mica being almost the only accessory minerals. The quartz shows slight signs of crush. The kyanite in these slides appeared to me in some respects abnormal, and I am much indebted to Mr. T. Crook, of the Imperial Institute, for checking my determination. Quart. Journ. Geot. Soc. Vor. LXIX, Pc. LI. H.H.T, Photo. Bemrose, Collo, Derby. SCHISTS anpd GNEISS FROM BRITISH EAST AFRICA. Summary and Conclusions. That part of British East Africa which borders on the Athi Plains, and extends westwards from Machakos up to the eastern edge of the Rift Valley, is an undulating country composed of foliated rocks of ancient appearance, among which biotite-gneisses are con- spicuous. Pegmatite-veins cross the foliation, and are not associated with intrusive granites or dyke-rocks, so far as my observations go. In the neighbourhood of the headwaters of the Turoka River, a group of altered sediments has been traced over an area of about 100 square miles, and these it is proposed to designate by the name of the Turoka Series. A large number of rock-types are found, varying from one purely arenaceous, forming the locally conspicuous hills from which the majority of the headwater streams take their rise, to beds of marble of considerable thickness. Other varieties have been mentioned above, the most important being a series of kyanite- gneisses or schists and a scapolite-garnet rock. A river-bank section has also been described, showing the local succession and the passage, as I believe, between a calc-mica-rock and a biotite-gneiss. Near the headwaters of the Turoka River, the dips of the planes of foliation of the various gneisses were consistently north-eastward or east-north-eastward. For permission to publish these notes, 1 am indebted to the kindness of the Magadi Soda Company, to whom also my thanks are due for allowing much information, incorporated in the accompanying map (p. 536), to appear. The locations of the fault- scarps, the principal of which are shown, have been obtained from the Survey maps of the Magadi Branch Railway, produced under the direction of Mr. T. A. Ross, Resident Engineer, to whom I tender my thanks for much kindness and sympathetic help rendered while I was in Hast Africa. I am also greatly indebted to Mr. Herbert H. Thomas, Sec.G.S., for kindly preparing the micro- photographs reproduced in the plate. EXPLANATION OF PLATE LI. Fig.1. Section showing the relationship of the hornblende-schist to the common type of impure marble. The hornblende-schist is shown on the extreme left, andthe marble on the right. The intermediate zone is mainly composed of hornblende after malacolite, calcite, and sphene. Ordinary light. Magnified 10 diameters. 2. Hornblende-schist. The photograph shows irregular plates of common green hornblende, locally replaced by almost colourless diopside, in a clear granular mosaic of plagioclase and quartz. Ordinary light. Magnified 9 diameters. 3. Kyanite-schist. The rock consists of kyanite, muscovite, biotite, and quartz, with subsidiary microcline. The grains are elongated parallel to the direction of foliation. Ordinary light. Magnified 14 diameters. 4. Garnet-Schist related to the kinzigites. The section shows pink garnets lapped about by a red-brown mica, and set in a base of clear felspar and quartz. Ordinary light. Magnified 10 diameters. 5. Epidote-hornblende-gneiss. The rock consists of yellowish epidote and dark-green hornblende, often closely associated, in a matrix of quartz and felspar. Sphene is a common accessory. Ordinary light. Magnified 16 diameters. 540 MR. L. F. SPATH ON [Dec. 1913, 25. On Jurassic Ammonites from JeBeu Zacuuan (Tunisia). By Leonard Frank Sparn, B.Sc., F.G.S. (Read March 5th, 1913.) [Puares LIT & LIII.] ContTEnTs. Page Ii, Thmumaclnoberry IRemRyANs) <-coscceccarcceoss douansecodsane: 540 IT. The Jurassic Rocks of Jebel Zaghuan and their Caphalopodmiannancmerces ee sreeeer acess eeeeee 541 III. Description of the Ammonites...................0+66- 547 I. Invropuctory REMARKS. Tue fossils described in the following pages were collected on a hurried excursion to the mountain of Zaghuan, the graceful, sharp- peaked summit of which is a prominent landmark that greets the eyes of travellers in the Regency of Tunis. Apart from being the most conspicuous mountain in the country—though inferior in absolute height to Jebel Chambi,—Zaghuan also forms the most important elevation of the Tunisian Atlas from a geological point of view, and the tectonic problems which it suggests are manifold and of exceeding interest. Without discussing these, it may suffice to mention that the late Dr. Pervinquiere in 1903* summarized the existing geological knowledge of the mountain as follows : ‘Massive limestones of Liassic age form the principal mass of the mountain, whereas the Oxfordian and ithonian play but a subordinate part in its constitution.’ As a matter of fact, the ‘ Oxfordian’ fossils of Pervinquiére characterize the zone of Peltoceras transversariwm, which corre- sponds approximately with what was at one time called in this country the zone of Aspidoceras perarmatum. On the other hand, he mentions Kimmeridgian forms, but includes them in the Tithonian. A later work by the same author” is devoted entirely to Tunisian cephalopods. Very few of the ammonites are of Jurassic age, however, and of these only about ten come from Jebel Zaghuan, none from the pre-Corallian deposits. Several other works on the geology of Tunis have been published since; but, so far as | am aware, no new facts regarding the mountain have come to light. I offer the following notes, therefore, in the hope that they may be of general interest ; for the study of the ammonites has revealed 1 ‘Htude Géologique de la Tunisie Centrale’ Paris, 1903, p. 253: ‘ Djebel Zaghouan.’ 2 «Htudes de Paléontologie Tunisienne: I—Céphalopodes des Terrains Secondaires’ Text & atlas, Paris, 1907. a Vol. 69.] JURASSIC AMMONITES FROM.JEBEL ZAGHUAN. 541 a few interesting facts, despite the circumstance that the small collection consists of casts and impressions which are not in a very good state of preservation. In consequence, specific determination has proved tedious, and, so far as some worn Upper Jurassic specimens are concerned, too unsatisfactory to warrant the ex- pression of an emphatic opinion. But the observations modify the current opinion, insomuch as there is now good evidence in favour of the presence of the zone of Reineckeia anceps, hitherto believed to be absent, with all the other strata intervening between the Middle Lias and the Corallian. Domerian (that is, Middle Liassic) ammonites are also recorded for the first time, and the discovery of a rich cephalopod fauna of Argovian age throws inter- esting light on certain ammonites described by previous authors as of Lower Tithonian age. It is a matter for regret that further stratigraphical cbservations or visits to the locality were impossible. Il. Tue Jurassic Rocks or Jepsen ZAGHUAN AND THEIR CepuaLorop Fauna. (1) The Lias. The Lias is represented at Zaghuan by thick, massive, bluish- grey limestones of confused stratification. The base is unknown, and it is impossible to say at present which are the oldest beds represented. ‘The late Prof. Baltzer* had collected a number of Liassic ammonites in 1893, and the list compiled with the help of Prof. Mayer-Eymar, and published in 1895,° included (besides belemnites and lamellibranchs) forms of the following Lower Liassic genera: Vermiceras | Arietites|, Coroniceras {| Arietites|, Arnioceras | Arietites|, Arvetites, Deroceras | digoceras|, -Andro- gynoceras | d*goceras|, Platypleuroceras | dégoceras|; and also the Toarcian Dactylioceras [| Coloceras| anguinum (Rein.). They are the only Liassic ammonites that have ever been recorded from Zaghuan (and, indeed, from the whole of Tunisia), and were collected below the ridge near the Col de Bourzen, partly among the screes. The matrix is not the same in all the specimens, and the curious mixture of Lower, Middle (to French geologists), and Upper Liassic forms seems to have made both Dr. Pervinquicre and Prof. Haug somewhat sceptical about the identifications. The former* records only little-determinable belemnites and Zerebratule from these limestones ; but M. Ficheur and Prof. Haug* found, besides belemnites ‘of the acuti group,’ ‘ Pygope’ aspasia Meneghini (Von buch), a brachiopod common to 1 and others. Dr. P. Lemoine * has recently created the var. indica for the Indian form of Ph. mediterraneum Neum. figured by Waagen,’ which occurs also in Madagascar, being distinguished by less inclusion and a wider umbilicus. All these Callovian forms have seven (or eight) constrictions. Dr. M. Canavari® describes the form from the Aspidoceras- acanthicum beds. As he figures only a fragment, it 1s impossible to say whether there is agreement with the Callovian forms; but the Argovian forms, at any rate, seem already distinct, and we may reasonably doubt whether the ammonite really persisted from the macrocephalus zone to the uppermost Jurassic, as is generally assumed. Phylloceras zignodianum (d’Orb.), a form which differs only in haying. more angular constrictions and a bifid lateral saddle, does not seem to occur in Mediterranean deposits. An eighth specimen in my collection from Zaghuan has straighter constrictions and a smaller umbilicus than the other seven; but as the specimen is worn, and as one of A. de Riaz’s figures * also shows constrictions which on the cast are almost straight, L include it here. Puytioceras cf. supprycHoicum Dacqué. (Pl. LIII, fig. 1.) 1873. W. Waagen, ‘Jurassic Fauna of Kutch’ Pal. Indica, ser. 9, vol. 1, p. 80 (pars) [as Ph. ptychoicum] & pl. vii, fig. 2. 1910. E. Dacqué, ‘Dogger é& Malm aus Ostafrika’ Beitr. Palaont. Geol. (sterr.-Ung. vol. xxii, p. 7 & pl. ui, fig. 1. One specimen in the collection belongs to the ptychorwcum group, but no labial ridges are visible. These, most probably, have been worn down; but, since they are absent on the chambered parts 1 from the bimammatum zone of Laufen, differs from Benecke’s type only in having a narrower umbilicus and less flat sides. Genus SowERBYCERAS Par. & Bon. SowrRbBYCERAS PROTORTISULCATUM (Pomp.). (PI. LIII, figs. 2a—2c.) 1893. J. F. Pompeck), ‘Beitraze zur Revision der Ammoniten d. Schwabischen Jura’ pt. 1, p. 53 & pl. ui, figs. 1-2. 1907. L. Pervinquiére, ‘ Etudes de Paléontologie Tunisienne: I—Céphalopodes des Terrains Secondaires ’ p. 15. This easily-recognizable ammonite is exceedingly common at Sidi Bu Gubrin, and I can identify twenty-one specimens with Pompeckj’s types, whereas only two specimens appear to belong to a different form of Sowerbyceras. They are all casts, and the measurements of eleven forms are as follows :— 1 ‘Beitr. z. Revision d. Ammon. d. Schwabischen Jura’ pt. 1, 1893, p. 28. 2 «Ammoniten d. Schwabischen Jura’ 1838, p. 901 & pl. xcvii, fig. 7. Q.J G.8. No, 276. ; 2P 566 MR. L. F. SPATH ON [ Dec. 1913, Diameter. Height. Thickness, Umbilicus, Millimetres. Per cent, Per cent. Per cent. 20 45 45 25 21 43 43 25 21 42 43 26 22 42 4] 27 23 44 45 22 25 45 48 24 36 42 47 25 37 46 48 22 41 44. 41 22 42 43 40 26 43 44 42 24 The other specimens are less well preserved. Istate the dimen- sions in detail, because they show that, despite some variation, the height of the last whorl is almost equal to the thickness ; whereas in Sowerbyceras tortisulcatum (dOrb.), which, moreover, belongs to the athleta zone, the proportion of height to thickness. is about 4:3. This, together with the sharp and high umbilical edge, was the principal distinction in separating the Argovian forms from A. d’Orbigny’s ‘ Oxfordian’ type. Pervinguicre records from Jebel Zaghuan one fragment and three: small ammonites, referable to Sowerbyceras tortisulcatum (d’Orb.), and associated with Ochetoceras arolicum (Opp.) and other Argovian ammonites. They also doubtless belong to the same form as the specimens here described. Sowersyceras cf. toryr (Munier-Chalmas). 1876. Ammonites (Phylloceras) silenus Dumortier & Fontannes, ‘ Deser. des. Amm. de la Zone & Amm. tenuilobatus de Crussol’ p. 33 & pl. y, fig. 2. 1877. Phylloceras silenus in Gemmellaro, ‘aune Giur. & Liass. della Sicilia’ p. 185 & pl. xvi, figs. 1-3. o 1907. Phylloceras loryi in Pervinquiére, ‘ Htudes de Paléontologie Tunisienne : I—Céphalopodes des Terrains Secondaires’ p. 15 & pl. 1, figs. 1-2. The two specimens which I refer to this form have the following dimensions :— No. 1. INO, 24. Didmeters joatancs cueaccsisense see 37 mm. 30 mm. Height of the last whorl ...... 50 49 per cent. of the diameter. Thickness of the last whorl ... ? 40 43 per cent. of the diameter. Whaling) scascocdadeoscoucegabcoe Wy 18 per cent. of the diameter. The narrower umbilicus, with sloping walls and rounded edge, combined with the absence of constrictions, seems to separate these two ammonites from Sowerbyceras protortisulcatwm (Pomp.). Since the specimens are not very well preserved, however, the identification must remain doubtful; and, in view of the fact that I collected a great number of Sowerbycerata and other forms of the transversarius zone at the same place, I hesitate to assume a later age for these two imperfect specimens. Pervinquicére mentions one specimen of Sowerbyceras lorye (Mun.-Ch.) from Zaghuan ; but, near the neighbouring Jebel Ben Saidan, he collected some twenty specimens of S. loryi in the A Vol. 69.| JURASSIC AMMONITES FROM JEBEL ZAGHUAN. 567 acanthicus zone, and he therefore regards the present form as the commonest Tithonian ammonite of Tunis. Its rarity or absence at Sidi Bu Gubrin is consequently very significant. Genus Lytocpras Suess. Lytocnras cf. GASTALDII Gemmellaro. 1870. Lytoceras montanum (pars) Gemmellaro, ‘ Fauna del Calcario & Tere- bratula janitor del Nord di Sicilia’ Giorn. Sci. Nat. Palermo, pt. 1, p. 33 & pl. vi, fig. 1. . 1872. Lytoceras orsinii Gemmellaro, ‘ Faune Giur. & Liass. della Sicilia’ p. 33 & pl. viii, figs. 2-3. 1875. Lytoceras gastaldii Gemmellaro, ibid. p. 114. 1898. Lytoceras cf. polyanchomemwm (Gemm.) De Riaz, ‘Description des Ammonites des Couches a Peltoceras transversarium de Trept (Isére) ” p. 39 & pl. xvi, fig. 4. The dimensions of the specimen which I refer here are :— AD AMACLE Tan Nese aes Saldana ccieae 37 millimetres. Height of the last whorl............ 38 per cent. of the diameter. Thickness of the last whorl ...... 35 per cent. of the diameter. (Whtnlowlbionisys” Géneeodeadhbeseceandonapaa 45 per cent. of the diameter. The wide umbilicus and hardly overlapping, slowly increasing whorls, with section slightly higher than wide, agree well with the type. The cast is smooth, however, and no trace of the original shell-ornament is left. Another specimen has a smaller umbilicus (40 per cent. of the diameter only) and possibly more flattened sides, similar to Lytoceras subtile (Opp.); but, as the specimen is somewhat worn, specific determination becomes very difficult. Oppel’s type comes from the Tithonian of Stramberg; on the other hand, L. polyanchomemum Gemm., with which A.de Riaz compares a specimen from the trans- versarius Zone of Trept, has been described from the macrocephalus beds of Sicily. According to Gemmellaro, the Sicilian form has an umbilicus measuring only 38 per cent. of the diameter, and a high elliptical section; De Riaz’s form is more evolute, however, and comes nearer the form to be described next. In Lycoceras orsintti Gemm. the umbilicus 1s 40 to 45 per cent., as in my two ammonites; but the better-preserved specimen, at any rate, seems to resemble the Argovian form more than it resembles this acanthicus-zone fossil. It is unfortunate that one cannot express an emphatic opinion on the age of these forms; but, as I have pointed out before, the fact is very significant that among a large number of forms belonging to the transversarius zone, the apparent exceptions should belong to the little-changing genera Lytoceras and Phylloceras. Lyrocpras aff. Ponycyctum Neum. 1873. M. Neumayr, ‘Fauna der Schichten mit <_> RG aeecd! SSS SSO SSS SSO SSeS OS a ese Sem ee C,So coe So oCSo Oe FeaaaosoS? é oa ae) mo (et ara ae ey | ae Mee ie I Mile to 1 mile, 74’ to 200 feet. 78 95" D5 Seale:— Horizontal: Vertical: (post-Boulder Clay). Ss. 9 = River-terrace (sand & gravel). 7 = Loam & brickearth 10 = Alluvium. | 8 = Glacieluvial gravel 5 = Glacial sand & gravel. 6 = Upper Boulder Clay. 3 = London Clay. 4 = Red Crag. Thanet Sands, ete. at the base; Woolwich & Reading Beds; Oldhaven Pebble-Bed. Lower London Tertiaries ; . [1 = Upper Chalk, yy — complete series from the Chalk to the post-Glacial gravels. I have mapped a con- siderable portion of the valley on the scale of 6 inches to the mile; and this work, together with the very large number of excellent sec- tions exposed in the valley, has brought out many interesting points. Almost any part of the valley might be chosen, but a sec- tion across it near Bramford’' or Ips- wich (see fig. 1) is fairly typical. Here, within a small area, pits can be examined where the Boul- der Clay is seen resting on Chalk, Lower London Tertiaries, Lon- don Clay, or Gla- cial Sands and Gravels. | The Boulder Clay formstheplateau-. land of Suffolk from 100 to 400 feet O.D., but here in the valley it is found at 30 to 40 feet O.D. (Ipswich railway- cutting, Sprough- ton, and Bram- ford). The man- ner in which the 1 Boswell, 1912 (33) p. 235 & map, pl. xxxiv. s Vol. 69. | THE AGE OF THE SUFFOLK VALLEYS. 589 Boulder Clay extends down into the small tributary valleys and sometimes thickens as it does so, being more denuded off the uplands, is brought out very strikingly in course of mapping the ground. The lateral valleys between Ipswich and Needham Market illustrate this point; and in the valley of the Belstead Brook (south of Ipswich), at Thorrington Hall Crag-pit, Boulder Clay ploughs down into the Pliocene Beds. Brett Valley.—At Layham, Hadleigh, and other places northwards to Nedging, similar phenomena are observed. Indeed, the Brett Valley is in many ways a small edition of the Gipping Valley. Box Valley.—At Polstead and Boxford in this small valley which runs southwards to the Stour, the Boulder Clay occurs as a valley-deposit. Excellent sections of the very chalky Boulder Clay of West Suffolk were recently exposed at the old Tudor house south-west of Boxford Church. Stour Valley.—the classical sections of Sudbury need only be quoted. The Rev. E. Hill is ‘inclined to look on them [that is, the beds of Boulder Clay|as deposited on the sides of pre-existing hollows ’." The sands and gravels occurring below this Upper Boulder Clay often behave rather curiously in the valleys of South Suffolk. In many cases they certainly appear to transgress the Hocene outcrops and dip down into the valley, resting in places on the Reading Beds (Whitton) or on the Chalk (Bramford). The difficulty is that here we may be dealing with gravels of two or more different ages. The fact that the gravels often contain much Jurassic débris and many flint-casts of Chalk fossils (low-zonal forms) makes it apparent that they are outwashes from the oncoming Boulder Clay and its ice-sheet.” Hence they should rather be classed as Upper Glacial with the Boulder Clay, than as a separate series. The loams which occur lenticularly in them, and are formed as washes from the Boulder Clay, are then easily explicable. This evidence from the Upper Glacial deposits goes to prove that the present broad type of valley-system was clearly pre-Upper Boulder Clay in age, and, probably in part also, older than some of the Glacial Sands and Gravels. The rivers, however, appear to cut through the rather different sands and gravels which form so large a part of the Suffolk heathland. LY. Evipencet or Agr appuceD From GrAcIAL DistuRBANCE IN THE VALLEYs. The phenomena discussed in this section belong to the valleys of the Alde, Deben, Gipping, Brett, Box, and Stour, but are best exemplified in the Gipping Valley where more work has been done upon them. The last-named valley is comparatively large, 1H. Hill, 1912 (384) p. 26. 2 Mr. Harmer has, I believe, suggested this on other grounds. 590 MR. P. G. H. BOSWELL ON THE | Dec. 1913, and from the nature of the beds disturbed lends itself to more detailed treatment. Gipping Valley.—The plateau around the valley is at a level of 150 to 200 feet O.D., and to understand the relief of the district reference must be made to a coloured contour-map (Pl. LV, fig. 1). The valley proper is mainly the portion below the 100-foot contour ; and it will be seen that, in places, all down the valley on both sides ‘bluffs’ or ‘spurs’ of land project inwards.1_ In most cases the bluff is indicated by the swelling of both the 50-foot and 100-foot contours, but sometimes by the former only. Over twenty definite cases of disturbanee of some or all of the beds of the district (Chalk, Thanet Beds, Reading Beds, London Clay, Crag, and Glacial Beds) were recorded by the officers of the Geological Survey, some being referred to glacial action as a cause.” More recent work has been carried out by Mr. George Slater, exceptional oppor- tunities having arisen in recent years for the detailed study of the remarkable glacial phenomena in this valley.° When the exact positions of all these sections showing intense disturbance and buttressing are plotted on the contoured map, it 18 found that each is located upon one of the spurs mentioned above, and that there are no records of any considerable disturbance in any of the numerous sections exposed on the plateau. The presence of disturbance upon every important spur down the valley (as noted by the Geological Survey, Mr. Slater, or myself), and the absence of such elsewhere, precludes the possibility of mere coincidence. The position of such recorded disturbances (but- tressing, contortion, shearing, transportation, etc.) is shown in each case on the map (PI. LV, fig. 1), by an arrow marking the direction from which pressure appeared to come, as determined by the phenomena there observed. In detail, the chief places are :— . (a) Gallows Hill, Barking, near Needham Market.*—Actually there are two hills bearing the same name. The sections show- ing disturbed beds on the more northern of the two spurs have not yet been described in detail, although good sections are at present visible there. Those on the more southerly spur and on the sides of the railway-cutting through it are now covered with talus and grassed over, but were noted by Sir J. B. Phear® and by the officers of the Geological Survey.° 1 Sir J. B. Phear seems to have observed some of these, and termed them ‘sand-cliffs’ in his 1856 paper (1) p. 434, &e. 2 Mem. Geol. Sury. 1881 (8) & 1885 (10), pp. 9, 18, &e. 3 Slater, 1907 (22) p. 186, & 1911 (32) p. 11. * Many of these projecting spurs into the valleys have received the name ‘Gallows Hill’ in Suffolk, the reason being obvious. Their conspicuousness also accounts for the term ‘ Beacon Hill’ applied to many of them. Some in the Gipping Valley are alleged to have been fortified by the Romans, and usec as stations overlooking and guarding the Roman road which runs up the valley on its course to Norwich. ° Sir J. B. Phear, 1856 (1) p. 436. ® Mem. Geol. Sury. 1881 (8) p. 7. s Vol. 69. ] AGE OF THE SUFFOLK VALLEYS. 591 (5) Opposite to Gallows Hill, on the left bank, the small tributary stream known as the Coddenham Brook joins the main river. ‘The result of this is to produce a strong bluff (Beacon Hill) at the northern end of Shrubland Park, pointing, as it were, up the valley, on account of the angle at which the tributary valley comes in. The high road cuts through the Chalk forming this bluff, and descends a steep hill. Some 15 to 20 feet of Chalk is thus laid bare on the roadsides, and a careful examination of this has convinced me that the whole of the material exposed is much disturbed: in fact, the Chalk is shattered to a breccia or conglomerate of Chalk pebbles in a marly matrix. ‘The top portion is much mixed and is full of flints, many large and green-coated (from the Thanet Beds), the bedding-planes of the Chalk being wavy. The surface of the latter is very irregular, and is covered by sand and gravel (pockets of which also occur in the Chalk) ; and above the gravel in one place buff and grey loam occurs. This shattering and loosening of the otherwise very firm Chalk accounts for the whole section being pale red in colour, owing to the percolation of ferruginous waters (not merely down the joint- planes, as is usually the case). ‘The disturbance probably accounts for the many ‘pipes’ formed here by root-action. It is note- worthy that at this hill the surface of the Chalk is about 120 feet above O.D., whereas its ordinary level in pits and borings in the immediate neighbourhood is about 100 feet above O.D. (c) Descending the valley, the next projection of importance that we reach is on the right bank at Baylham. The Chalk-pit east of the high road shows much disturbance of the strata, and has been figured by Mr. G. Slater." (d) At Claydon, on the left bank, an important bluff occurs, and luckily a large Chalk-pit is excavated in it. The remarkable section here, illustrating the work of the valley-glacier, was roughly figured and described by Mr. W. Whitaker,” and later carefully worked out and drawn by Mr. Siater.® (e) The spur near Old Hall, caused by the union of the small Akenham Brook with the main stream, contains a pit in shattered Chalk, but reference will be made later to the results of mapping this area in detail. (f) We meet no other striking sections until we reach the curious spur on the left bank, a short distance north-east of Sproughton Church. However, the 6-inch mapping of the right bank from Little Blakenham, through Bramford to Sproughton, brings out many anomalies, and there seems to be a probability of disturbance east and south-east of Sycamore House, and on the 1 Slater, 1907 (22) pl. v, fig. 12. 2 Mem. Geol. Surv. 1881 (8) p. 10. 3 Slater, 1907 (22) pl. v, fig. 7. 592 MR. P. G. H. BOSWELL ON THE [ Dec. 1913, hills near Bramford Park.! The hill above mentioned, north-east of Sproughton Church, is almost converted into an island lying in the valley by the road and railway-line which cut across its neck. Indeed, if for any reason the river- system were revived, the Gipping would certainly take the shorter course across the neck, and leave its old winding channel as an oxbow lake. (This seems to have happened with the Stour near Sudbury: see p. 596 & Pl. LV, fig. 3.) A pit on the south-east side of the spur shows Boulder Clay ploughing into Thanet Beds; but it was the map- ping of the north-western border which made evident the fact that practically the whole hill was intensely disturbed.” (g) The valley now broadens out before reaching the estuary and the sea, but an important hill between the Hadleigh and London roads at Ipswich partly bars the way (fig. 4, p. 602, extreme left). It is not often that geologists ere favoured by circumstances such as the following. The Great Eastern Railway main line to Norwich and Yarmouth makes an admirable cutting straight through the hill, and the remarkable disturbance of the strata exposed at the time was noted by Wood & Harmer,’ and by Mr. W. Whitaker,* in the Geological Survey Memoir. Later, the cutting was widened on the north-east side, affording a magni- ficent section, which was accurately worked out by Mr. Slater in 1900°; once again, in 1911, the cutting was widened on the south-west side, and so provided another excellent section. In the latter part of 1912 the north-eastern embankment was again cut back. These recent sections will shortly be figured and described by Mr. Slater. Further, in 1905, the municipal authorities of Ipswich, wishing to provide work for the unemployed, decided to cut away and level this hill to a considerable extent, with the view of providing suitable building-sites. The work continued until i910, almost 200 men at times being employed. Full advantage was taken of these excavations, which were carried out generally in a north-east and south-west direction. The sections were carefully drawn and photographed before they passed out of existence, and their value lies largely in the fact that, with the railway-cutting, they give a faithful picture of the disturbance along the line in which the ice moved and transversely to it.° The cutting of trenches for sewers, etc. over this estate has recently revealed still more evidence of disturbance. (h) Another hill occurs immediately south-east of Ipswich Railway -Station. Some considerable disturbance is seen in cuttings here, and the strata met with during the making of the 1 Boswell, 1912 (33) pl. xxxiv. 2 [bid. pl. xxxiv. ’ Wood & Harmer, Rep. Brit. Assoc. 1868 (8) Trans. Sect. p. 80. See quotation on p. 584 of this paper. 4 Mem. Geol. Surv. 1885 (10) pp. 10, 93, ete. > Slater, 1907 (22) pl. v, fig. 1. & Ibid. pl. v, figs. 2, 3, 4, 5, & 6. A Vol. 69.] AGE OF THE SUFFOLK VALLEYS. 593 Ipswich Tunnel appear to have been anomalous in position. Irregularity was noted by the officers of the Geological Survey here, and at the old Stoke brickyard (which has now disappeared), close by on the south.’ “(7) Across the valley, on the left bank, there are two spurs projecting southwards into the lower ground, near Dale Hall, north-north-west of the town. Excavations in Messrs. Bolton & Laughlin’s brickyard in the more northerly spur have developed a fine example of glacial disturbance, described and figured, with photographs, by Mr. Slater. There are several pits showing much disturbance (sheared and puckered London Clay, etc.) in the southernmost of the two spurs—that of Broom Hill. (j) At the eastern end of the town of Ipswich, disturbance was noted and figured by Mr. W. Whitaker in the railway-cutting south of the cemetery*; but no good sections have been visible for some time. (k) In a road-cutting and other excavations in the next hill on the south (that of Grove Lane, Ipswich), Mr. Slater described and figured contortion and ploughing-up of the beds.* Red, highly ferruginous, glacieluvial gravels occur here. No sections are exposed in the last spur immediately south of Greenwich Farm, neither has this yet been mapped on a larger scale, From these observations it is clear that the Gipping Valley is considerably older than the advent of the vallev-glacier, and not only the main valley, but also the two or three chief tributary valleys, as shown by the buttressing of the ice upon the spurs formed on the southernmost side at their union with the main valley. The final test of this deduction lay in mapping two of the spurs where no section had been exposed. Like the attempt to map the Hadleigh-Road hill, west of Ipswieh, it was found some- what difficult to do this satisfactorily. The first spur chosen was that north-east of Sproughton, and the result was that Glacial deposits, Eocene beds, and Chalk were found to be much mixed, and all at abnormal levels (see Hazel Wood on the 6-inch map).’ The second case was that of the hill near Old Hall, west of Akenham, 4 miles north-west of Ipswich, where similar results were obtained. ‘here is also a chalk-pit here, where the beds appear to be much shattered.“ The Glacial Drift is so irregular, and members of the series pass so frequently one into the other, that the attempt to draw hard-and-fast boundary-lines on a map often results only in introducing artificialities. The most exact 1 Mem. Geol. Surv. 1885 (10) pp. 11 & 93. 2 Slater, 1911 (32) p. 13 & pl. vil. 3 Mem. Geol. Surv. 1885 (10) p. 89 & fig. 25. 4 Slater, 1907 (22) pl. v, figs. 9, 10, & 11. ® Boswell, 1912 (33) pl. xxxiv. ® Ibid. pl. xxxiv. 594 MR. P. G. H. BOSWELL ON THE [ Dec. 1913, mapping can be at best an approximation. It seems more than probable that if other hills on the flanks of the valley were ex- cavated, as those farther south have been, just as remarkable a series of phenomena would be exhibited. The length of the portion of the valley that has been dealt with in detail above is some 14 miles. It is not possible, nor is it necessary, to discuss the other Suffolk valleys in such detail. The number of sections exposed on spurs in the other smalier valleys is naturally less, but enough will be summarized for the purpose of showing that the same conditions obtained. Alde Valley :—(a) There is a spur on the right bank a mile and a half south of Framlingham, through which runs a railway- cutting showing contorted beds.’ The officers of the Geological Survey here noted ‘sand, with a little gravel. At a point about 130 yards west of the 89th mile- post, is earthy gravel with a seam of clay showing strong contortions and even inversion. (6) Upon the spur on the left bank, a mile south of Framling- ham, contortion and abutting of the Boulder Clay against other beds was noted.” A detailed description is given in the Geological Survey Memoir, and the irregularity of the beds, as observed in mapping, remarked upon. (c) The spur on the left bank at Parham Wood shows some disturbance, again first noted by the officers of the Geological Survey.’ A steep-sided channel eroded in Crag sand was observed in the railway-cutting. (d) In the spur south of Snape Church, several pits, including a brickyard, show much confusion of the beds. These were observed by both 8. V. Wood, Jun., and the Geological Surveyors.* (eé) Spurs at Blaxhall, on the right bank of the river, contain two pits, which I have figured, disturbances being described and, in one case, figured by the officers of the Geological Survey. (f) The rise upon which Aldeburgh itself stands evidently proved an obstacle to the ice: for, in the brickyard, intense con- tortion of Chillesford Clay and Crag, etc., was to be seen some years ago. he course which the River Alde now takes for 10 miles southwards before entering the sea is post-Glacial deflection due to southerly tidal drift. Other smaller disturbances also occur in this valley. Deben Valley.—Comparatively few sections are exposed in this smaller valley, but there is evidence of disturbance. (a) At the spur at Naunton Hall, Rendlesham, on the left bank.’ Here, in the Stackyard Pit, a mass of Boulder Clay with almost, if 1 Mem. Geol. Sury. 1886 (11) p. 33. * Ibid. pp. 33, 34. * Tbid. p. 34. 4 Ibid. p. 29. ° [bid. p. 40. 4 Vol. 60. AGE OF THE SUFFOLK VALLEYS. 595d 9 not absolutely, vertical sides occupied a deep gully in the Crag, the trend of which was north-north-westerly, pointing up the upper part of the valley, but almost at right angles to the course of the Deben at this place. (6) The disturbance at Hasketon brickyard should be mentioned here. It may be connected with the valley-ice, but is local im character. (c) The anomalous levels of the Reading Beds, London Clay, and Crag at Woodbridge, and the sequences of strata met with in well- borings, point to much disturbance (see p. 607). : Brett Valley (Pl. LV, fig. 2).—This is a miniature of the Gipping Valley, showing similar phenomena on a smaller scale, (a) From the irregularity of the beds, there seems to be dis- turbance at the spur on the right bank, south of Semer Church, and also farther south near Cosford Union Workhouse. (6) At the big spur north-west of Hadleigh, on the right bank, considerable disturbance of Hocene beds was figured by Mr. W. Whitaker,! and, later, different sections were figured by myself. (c) The hill on which Hadleigh Railway-Station is situated, on the left bank, is capped by disturbed Glacial beds, but no good sections lower down the hill are visible. (d@) In the Geological Survey Memoir disturbance is noted and figured at several places on the right bank: for instance, near Overbury Hall, Layham.? The spur south of Layham Church contains a brickyard where fine contortions in loam, sand, and Boulder Clay were to be seen. (e) There is good evidence of disturbance near Shelley Church, Kocene beds, etc., occurring at very unusual levels.’ Stour Valley (Pl. LY, fig. 3).—As would be expected from the position, disturbed beds were noted at the brickyard at Boxford, where the valley and stream change direction from east to south, the River Box being tributary to the Stour. The brick- yard is now disused, and the sections are overgrown; but contorted London Clay, Glacial Sand, and Boulder Clay (the last extending down into the valley) were observed and figured in: 1885." The Stour, cutting, as it does, its valley largely through Chalk, is not quite comparable with other Suffolk rivers. The dis- turbance also seems to be of a type rather different from that observed farther east, being characterized by an accompaniment of large quantities of chalky sands and bedded chalky silts or loams. ‘These are not strictly paralleled by anything in the east- of the county, although similar sands and silts do occur in very 1 Mem. Geol. Surv. 1885 (10) p. 21 & fig. 7. ? Tbid. pp. 88, 100, ete. 3 [bid. pp. 9-10. 4 Ibid. pp. 18-19 & fig. 5. 596 MR. P. G. H. BOSWELL ON THE [ Dec. 1913, small quantity, as, for example, at Barking and Stowmarket, etc. The occurrence of this large quantity of chalky material is clearly due to the higher level of the Chalk surface hereabouts, its re- latively greater area of outcrop, and thinner overburden of "Eocene and Crag deposits. It seems probable that the absence of any notable thickness of Londen Clay has in no small degree modified the nature of the disturbances. Some contortion and minor faulting of the silts at higher levels is doubtless due to slipping on the valley-slopes, as explained by the Rey. E. Hill in his clear and accurate description of the Sudbury Glacial sections’; but it seems to me quite probable that some of the disturbance on the Sudbury Town spur, and on the Ballingdon Grove spur on the opposite bank, may be due to buttressing upon them. Contortion, inversion, and buttressing of the beds are to be seen, and mapping on a large scale might throw light on the matter. In the brickfield situated on the spurs a mile west-south-west of Little Cornard Church, occur good exposures of bedded silts and chalky sands completely enclosing huge boulders of altered or redeposited Chalk. Their appearance at once recalls the Cromer and Norfolk coast Chalk-masses, as was observed by Mr. Hill,” who points out the narrowing of the valley here, and suggests that the great boulders of remanié Chalk were stranded in their present position, I am compelled to agree entirely with this view, and it is interesting to draw attention to the form of the valley immediately above these spurs projecting from the plateau (Pl. LY, fig. 3). The 100-foot contour is here thrown back into a bay-like form, and a tract of absolutely flat country a mile long and nearly as broad occurs. In this embayment the slope ear the 100- and 200-foot contours to the river is not gradual, but is the normal gradient of the valley-flanks near by, reaching river-level immediately west of the 100-foot contour. This comparatively extensive flat plain is in many parts liable to floods, and is traversed by ditches and small streams which drain it. t is largely covered by alluvium, but loam and gravel were also mapped. There seems little doubt that here the Stour in pre-Glacial or early Glacial times made a big bend similar to those in the upper part of its course; but eventually (perhaps in consequence of increased volume due to the melting of the Upper Boulder-Clay ice), it cut off this bend, and took its present direct course, producing a flat river-formed plain and an oxbow channel which has been silted up. The meniscus-shaped outcrops of loam and valley-gravel mapped by the officers of the Geological Survey bear out this view. (Compare the Sproughton spur in the Gipping Valley, p. 592.) In the investigation of these disturbances due to glacial action (many of them on a considerable scale), every example of contor- tion and displacement recorded or observed in the county is found 1 B, Hill, 1912 (34) p. 27. 2 Thid. p, 28. 4 Vol. 69.] AGE OF THE SUFFOLK VALLEYS. 597 to lie on the flanks of the valleys. Nowhere in the numerous sections on the plateau have such anomalies been observed (al- though one or two hypothetical sections have been drawn on quite insufficient evidence), neither do the well-records there show anything but a normal state of affairs. The fact that marked disturbance occurs only in the valleys, seems, therefore, to be more than mere coincidence. It is probable that the ice-sheet which produced the Chalky and Chalky-Kimeridgic Boulder Clay of the plateau rolled upon a bed of Glacial Sand and Gravel, producing the generally flattened character of the latter deposits. The conclusion drawn, therefore, from a study of the spurs of the Suffolk valleys is that the pre-Glacial or early Glacial contours of the area were, in the main, much as they are at the present time. V. Evipence or Ack From Wett-Borrnés, ETC. The records of the strata shown by over 600 borings in Suffolk and on the borders of Essex and Norfolk have been analysed, Many of these, for various reasons (not the least of which is the lack of information as to altitude and exact situation of the boring), were of little or no use, but over 200 were accurately plotted on a map of Suffolk (Pl. LIV). The sites of most of these borings, especially the critical ones, have been visited, and in many cases the exact site and the height above Ordnance Datum have been’ obtained where they were previously missing in the records: The production of a sub-Dritt contoured map was at first attempted, but was abandoned on account of the necessarily arbitrary grouping of the strata in the well-borings, ete., where Glacial beds of sand, loam, and clay were resting on Crag sand (=decalcified Crag) and Eocene clays and sands. No geologist having been present when most of the borings were made, it appears that the only bed the level of which can be widely relied upon is the Chalk. On the map (Pl. LIV) the approximate contour-lines for the Chalk surface on the plateau are inserted, in order to bring out the anomalous levels in the valleys where buried channels occur. The noteworthy ‘crowding-up’ of the contours in the south and east of the county is explained when the present extent of the Eocene deposits is marked upon the map. The gradient of the Chalk surface where it crops out, or is covered only by Drift,is closely 7 feet to the mile; but, where covered by Eocene deposits, it dips almost 30 feet to the mile.» The unconformity of the Eocene upon the Cretaceous 1s well brought out, when it is noted that the dip of the Chalk zones is about 15 feet to the mile. his unconformity is further 1 Ina recent letter Mr. F. W. Harmer tells me that some years ago he spent much time in trying to work out the sub-Glacial contours of Norfolk by the same method, but without success. 2 Boswell, 1915 (87) p. 18. Qed. G.S: No. 276. 2k 598 MR. P.G. H. BOSWELL ON THE —_ [Dec. 1913, emphasized in the south of the county by the transgression of the Tertiary strata westwards over successively lower zones of the Chalk. Naturally, the larger valleys cut back these Chalk-surface con- tours, and these take either a sharp V-form, or a closed oval form where a channel exists; but the small scale of the map prevents me from showing these anomalies, only the chief borings in each valley being inserted. ‘The figures, in all cases, refer to the position of the top of the Chalk with reference to Ordnance Datum, the negative sign referring to depths below O.D. In the western part of the county the Drift rests directly on the Chalk; but in the eastern portion the borings show Eocene and Pliocene strata between. As, however, it is often difficult to fix the exact base of the Drift in the well-section when it overlies Crag and Eocene deposits, the upper surface of the Chalk has been recorded in each case; it can be placed with certainty, and serves the required purpose equally well. The data are, nevertheless, insufficient to yield an accurate hypso- metrical map. In this way some striking facts are brought to light. The existence of buried channels of the Drift at Glemsford,* Brettenham,’ Ipswich,’ and possibly Woodbridge* has previously been pointed out. Similar ones have been described on the west of the area at Hitchin’; in the Cam Valley in North-West Essex® ; at Bishop’s Stortford’; and at Sandy in Bedfordshire.* Examination of the well-records shows that each one of these radiating Suffolk valleys of any size contains a buried channel. The evidence for these channels will now be considered in detail. (a) Stour Valley.—The remarkable thickness of Drift met with in the boring at Glemsford, north of Sudbury, has been frequently commented upon. The boring was begun at 123 feet O.D., and, after passing through 471 feet of Drift, reached the Chalk. It is not necessary to reprint full details, but the chief groupings were :—Gravel and sand 51 feet, Boulder Clay 218 feet, sand and gravel with flints 201 feet, Chalk 40 feet. This section makes the level of the Chalk —348 feet O.D., while at neigh- bouring places it crops out at a level considerably above O.D. (for instance: Clare + 151 feet, Sudbury +110 to 120 feet). Moreover, as Mr. Whitaker points out, the section begins at some depth below the great mass of Boulder Clay, which on the plateau near by reaches a height of more than 250 feet O.D. (b) Brett Valley.—At Felsham, near the head of the valley, the Chalk surface occurs at 120 feet O.D., but at Brettenham and. 1 Whitaker, 1906 (21) p. 58. 2 Tbid, p. 32. 3 Ibid. p. 77, etc. 4 Whitaker, 1903 (20) pp. 36 & 47. 5 W. Hill, 1908 (28) p. 8, & 1912 (85) p. 217. 6 Whitaker, 1890 (13) p. 338. 7 Irving, 1897 (16) p. 224. 8 J. Hopkinson, Q. J. G. S. vol. lix (1903) p. 49 (discussion). 4 Vol. 69. ] AGE OF THE SUFFOLK VALLEYS, 599 Hitcham in the valley, as the Rev. E. Hill has pointed out in the course of correspondence, there seems to be good evidence of deep hollows in the Chalk. In the Brettenham well (280 feet O.D.) 312 feet of clays and sands were met with above the Chalk, the upper surface of which here is thus —32 feet O.D. Myr. Whitaker classes all these beds as Drift, but Mr. Hill suspends judgment. From the mixed nature of the beds in the section, one would feel inclined to suggest that Eocene and Pliocene deposits had been ploughed up and incorporated with the Drift. The following is the section under discussion :— Thickness Depth in feer. in feet. { Blue Boulder Clay with Chalk stones ......... 141 141 Rioughivmedtisam din ti. acer: deces becsenrdaeeassele sis 16 157 Loamy sand with grey clay ...............s0.s00+0 D 162 Guacran | Pine red running sand ..............0s.sseseeeenees 30 192 Drirr, + Grey clay mixed with red sand ...............+-- 6 198 * | Rough red sand with shells ..................... 15 213 Hard rocky substance ................sececeeeees is 4 217 (Choravalkonmneres wos) © pAdassecodonecusnagecoorvesbbubocbeonon 5 222 \ Plastic clay with flints (? Boulder Clay) ...... 90 312 CHALK, with occasional beds of flint................20.0e0e00 0 232 544 Certainly plastic clay is found in the Lower Kocene beds, but never more than a few feet thick. It should also be pointed out that Brettenham Park is about 4 miles north of the present limit of the Lower London Tertiaries; they are present at Sudbury, Hadleigh, and Ipswich, but are rapidly thinning off by erosion. Detailed mapping of the beds has proved that, even after they have disappeared north-westwards, material from them is included in Glacial Drift north of their outcrop. Their previous farther extension north-westwards is thus indicated; they and the Crag which lies above them were considerably eroded in pre-Glacial and Glacial times. A boring in Hitcham Street (at 175 feet O.D.) went through 104 feet of Drift without reaching Chalk, which normally crops out in the vicinity at over 120 feet O.D. The Rev. E. Hill remarks that this ‘is interesting as revealing a buried valley.’ At Cross Green, just to the north-east, 250 feet of Drift were cut through before Chalk was reached. As we descend the Brett Valley, the Chalk is seen to crop out at the surface at 120 to 180 feet O.D. at Monk’s Eleigh (zone of Marsupites), Chelsworth, Bildeston, Nedging (zone of Actinocamax quadratus) ; and at Cosford Bridge and Kersey, 2 miles north of Hadleigh, at about 100 feet O.D: it is also found in borings at Whatfield at over 130 feet O.D. At Hadleigh, however, a second buried channel appears to be revealed. A boring made for Messrs. Woods & Co., at 90 feet O.D., shows 90 feet of Drift lying directly upon Chalk, no Crag or Eocene deposits being recorded. A second boring at the Maltings (80 feet O.D.) cuts through a series of sands and clays 100 feet thick, which Mr. Whitaker 2R2 = *- 35 o"Sre ce. “TOUL TO} JOO) QOP 789A, *YOUL T OF SOTITa P r]LPWOZMOTT —:oTVoy Co a See el SOW V zt r ) ™y a —— =} ee vv ill 7 aM Orel) Demet hs Saar * MI apoio. hi) wh sll : Wr ei {Ia W val al cis aera | Mure FEE ie eit ~wl— pees Tita tind | hee | a > ar SCO Wh oe Sa Ln oa a oy ~ y; Y ag ssuopinyy $ ¢ Zz I 6 ‘31%9S v e= mae wE aouUMAyWA YOO Ww sjawuvYys s01INTY ————— f 5) Sy] a “Ylaq fo Jauiiwyo fo as4109 ajquqolg mmcmm oe “SOU DAI) ~~~ ~~~ + SIO ‘0 Of passafas yyvyg ayy fo Joy SPISTOIEM & aif] fo 1209] A] IA1F ssoqueue ayiz, FY ‘ssilz10g fo noyisog Simmoys \ or i vel yormsdy jo deyy-yojoxS SHIOM SeD 7s! OVA? fo ; aes - ly ie ip N =~ aN See omar eet eel fat oe ) 0 / Fe UOHWeIS Lemprey = Ir 2. 9 gla gooseseseeeo a ow 2 oS= SSL Arey St 82" 4 \l6r~ : 1999q 4S yUSIUZTD 3S+ au yong) Ayruray, ! \ s0usIMe7T| t4s Sp bpiaP? ne ~. {S Tryus05 = Seen 4S + A Vol. 69.1] THE AGE OF THE SUFFOLK VALLEYS. 603 to the south-east at 100 feet O.D., but the following table shows the actual levels found :— TABLE oF Borines In THE Gripping VALLEY—Urpsrr Porrion. | Height | Thickness Chatk-surface Locality. |above O.D.| of Drift | referred to | in feet. | wm feet. | O.D. in feet. | leans aa eee = ss imewelie tee 9) ee 27 127 CON a OVdpNewtom es) eect seaseetenteae tee Nia LO Kea Wien 12S, | + 82 | IBIeNOeANIIEN7 04 Lingnation ssponbnnondaceEabaanod| 160° +>) 100 + 60 Stowmarket—Malting.................. | gE | O74 + 345 | Do. Brewery eecc.ceecesees | 100 71 4 29 Do. Brickyard............... | 135 | 13 See Do. Waterworks ............ | 100 | 774 + 223% Do. Hewitt’s Mill ......... | 95 100 = 5 Creating St beten wee. asn-6.405- chee 164 | 145 Wo aie HE) Womibs meray week css cuedioes acacia stars | 100 257 | P+ 431 Needham Market .....................25. 100 — ; +100 Chalk-pit near Creeting Hall......... 100.— | — | +100 Other wells show a corresponding thickness in Drift, but that at Creeting St. Peter is a little surprising, as it lies rather outside the present valley, while Chalk is exposed at a higher level at a pit in the valley (Creeting Hall). ‘The surface of the Chalk is very irregular here, but a little lower down the valley the formation crops out again at the levels to be expected, 100 to 120 feet O.D. (Baylham, Bramford, Claydon, Needham, etc.). A number of fresh borings have recently been put down at Ipswich, and these give more definite information as to the extent of the buried channel there. Fig. 4 (p. 602) is a map of Ipswich upon which these borings have been inserted. In the area round the Dock some forty trial-borings, etc., had already been recorded; in 1912-13 over thirty more have been made in connexion with the proposed Dock-extension. Space permits only of the chief of these being inserted. At present, only an average example of the new borings need be quoted :— Feet. ANU ay rl maa, Teo eresim El CA eos Ae ca naaahbsosanesdcceeesod 2 Terrace. River-gravel ...............ccscsscecceeeeeses 7 (ON ALE ie. cots na eH aSeISPAE ICR COB iGe IS OP OGRE MEE ne RN reat tee 10+ Many of the borings are begun beneath low-water, which is, for spring-tides, —4 to —6 feet O.D., high-water being +9 feet O.D.? The level of the Chalk thus indicated varies from —25 to —32 1 Two accounts of this well do not agree; see Whitaker, 1906 (21) p. 39. 2 For this information, and that relating to the new Dock-borings, I have to express my thanks to Mr. Thomas Miller, C.E., Engineer to the Ipswich Dock Commissioners, and his son, who have very kindly given me every assistance, 604 MR. P. G. H. BOSWELL ON THE [ Dec. 1913, feet O.D. Along the broken lines on the map, near the Dock- entrance, there seem to be hollows in the Chalk: that on the west being indicated by the old series of borings, that on the east being indicated by the new. However, the hollows do not appear to be of any great extent or importance, though they may be the end of the proved deep channel. The well-boring for the Gas-Works in Patteson Road (1905) yields evidence of a Drift-filled hollow, but whether it is connected with the deep channel, or with the minor channels at the Dock-entrance, we do not know. The particulars of the boring are :— Ground-level +14 feet O.D. Thickness in Depth in feet inches, feet inches. JW feos Gros aa AA EP eRe aa eno oe 5 6 6 ae | Coarselballast tas. -cauceesseceeeees 3 0) 8 6 Tee TRIAS TMK 40 ona see teen Bc unl E() Liev 2 ? | Coarse dark ballast ............... 1] 6 23 ©) (aliivciatalonmberseee sects somes costes a 6 27 6 Running sand ...............0..65 8 0 35 6 | Darkal ony ence ates 6 0 41 6 | Wonk Cleny * scscsccoconso0gsoaes 2 0 43 6 | IORI SENG | SHeagsoovssrcoonbobbnenados 6 6 50 0 Ibyoimvdlorn Olen? = Gos ssoncscancosdauebe 5 9 55 8) Daten. { Loam and a Mah be Rae STM aise 9 6 65 3 | Light-brown clay .. ............... 0) 9 66 0 ,; Flint-bed and gravel............... 18 0 84 0 | Light coarse sand ............-..... 2 0 86 0 SEXNGISHOMNG Sonhsaossechnuoce sddonoonn iL 0) 37 0 (SBilint=bedsera eee seccrecr sree 3 0 90 0 CORAT e peer Machen oaeeue ate semen coe edaciaee 160 0 250 0) Surface of Chalk —76 feet O.D. If the hollows indicated by the Dock-borings and this Gas- Works boring are connected with the proved deep channel, the result would be interesting, as their direction is at right angles to that of the proved channel, and it would indicate that the hollow changed direction sharply with the present estuary. Until recently there were two anomalous borings reaching Chalk at considerable depths only. The details of the strata bored through have been frequently reprinted,” and it is unnecessary’to give more than a summary here :— (1) College Street, Messrs. Burton §& Saunders. (14 feet O.D.) Feet. EDU Tt aces een en Roth Tene Mee are 130 CONNIE ch a aol tion aan ea ine alas aaa 1913 Chalkslevelvisestaare vesa-oc teenies —116 0.D (2) St. Peter’s Quay, Messrs. Cranfield. (10 feet O.D.) Feet. AD esh fe RSet Ate ar ce EM a stain in ore 127 Cupar Te ei) ie SUED ie a eae Re ee 81 GChalik-levell thee eats baad eee, —117 O.D 1 The well-sinkers’ term only. The grouping of the beds is mine. 2 Mem. Geol. Surv. 1906 (21) p. 74, ete. ¢ Vol. 69.] AGE OF THE SUFFOLK VALLEYS. 605 Other borings put down in Ipswich and the neighbourhood since the last list, published in 1906,' prove the Chalk to lie at the customary levels; but a boring begun in December 1912, and finished early this year (1913), immediately west of the town, proves the extension of the buried channel farther westwards, I was able to see the early part only of the boring, and I have to express my gratitude to my friend, Mr. Slater, who, being on the spot, carefully made detailed notes and kept samples of all the beds met with. I have used his notes freely in the following :— L[pswich.— Boring for water for the Diesel Engine-Works by the river immediately west of the town. (Height above O.D.=23 feet.) Thickness Depth am feet. in feet. eddishysantd atewasous naetensdelenaecs 4 4 Teprge Taa ah { Ferruginous flinty gravel and sand... 25 29 (ieSilltiveclanye My Aen oastiee cesta seeasoas eens 21 50 | Sharp, dark-grey sand, with specks of CLAN NS ae eSNG ENS eit eSaisct 8 58 | Wor wtitinerisctscencee sums alse: cosas 7s 654 Similar sand, but with potato-sized | boulders of chalk and flints ......... 93 79 Drirt. He WORTSED PCY SAUNAS ..cewuselaen sites: «eens 17 92 | Chalky flint- gravel; some quartz herenbouliderst: Peeves. case sap er elen oe SR ACa RY 5 97 | Chalk (remanié material) ............... 3 100 |) Clap SEY ede ElL) aon Acconace Unceddosndpecdec 4 104 l@hiliky(asibetore))eenesmereseee rece tess. 6 110 \ Very coarse gravel .................0. econ 3 113 CHAE Teen etesae eee estas haste Ress tet sjtenavaiseyens se cee'd 112 225 The first 29 feet is typical terrace-material, with iron-stained and much-altered flint, of a prevalent reddish or brownish tint. The grey sands and silts from 50 to 654 feet are, from the samples, obviously washes from the Chalky - Kimeridgic Boulder Clay : hence their colour. The uppermost 8 feet of this is a micaceous sandy loam. ‘Two boulders of Chalk were passed through (from 97 to 100 feet and 104 to 110), consisting of rubbly altered material like the transported boulders at Little Cornard (see p. 596). Mr. Slater has recorded a huge transported boulder of Chalk, 42 feet long, higher up the valley at Claydon.* The 4 feet of gravel between the two Chalk masses is rather peculiar. It consists of a great deal of flint, much of it in the form of fine chippings, in a matrix, of chalky sand. This flint is brown and black in colour and very fresh, even the thin translucent edges being un- altered, though perhaps a little rounded. All the flint in the Drift portion below the terrace-material is fresh and unaltered, just as it came from the Chalk. Vein-quartz pebbles frequently accom- pany it; but it is the last 3 feet of gravel, resting directly on the Chalk, that is the most interesting and important part of the section. ‘This gravel consists of fresh dark-brown and black flint- pebbles, about 3 inches in diameter, many of them beautifully rounded, but still showing over parts of them the original white 1 Op. cit. 2 Slater, 1907 (22) pl. v, fig. 7. 606 MR. P. G. H. BOSWELL ON THE [ Dec. 1913, cortex. Others are subangular, in the process of being rounded off, their edges smooth, but their substance still unaltered. Mr. Slater also secured one well-rounded pebble of Jurassic limestone. The appearance of these rocks, from their shape and lack of alteration, at once suggests pot-hole action; but pot-hole action where Eocene and Crag detritus had no entry, for there is an entire absence of iron-staining. Very different are the terrace-gravels, also the glacieluvial gravels, with their intensely iron-stained and battered flints, and the ‘ Cannon-Shot’ Gravels, with their ferruginous flints often beautifully rounded, as our specimens are. It is possible that the flint-gravels so frequently noted at the base of other buried channels may be similar, but the well-sinkers would probably not record the difference in character of the pebbles. In normal sections in the district a band of glauconitic green-coated flints, of the usual irregular shape, generally occurs at the base of the Thanet Beds, lying directly upon the Chalk. TABLE Or Bortnes InN THE GipeInG VaLLEY—Lower Portion. | Height | Thickness \Chalk-surface Locality _above O.D.| of Drift | referred ito | in feet. in feet. | O.D. in feet. | | Bramford Chalk-pits ..................+-- 100+ — +100 Sproughton Clay-pit ...............0..00+) — — + 50 | Ipswich—Henley Road ...............--- 150+ 136? + 14 Do. Tollemache’s ..............---- | 35 35 + 0 Do. Cliff Brewery .................- 34 34 | + 0 | Do. Co-operat. Society, Carr St. 40 42 eee eke Do. Stary iH act omyaeeeeneeee eens: 47 52 — 3s Do. Unicorn Brewery ..........-- 26 32 | — 6 | Do. Burton’s Jam Factory ...... 16 35 Weert ls, Do. Mason’s Paper Mills ......... 13 29 — 16 Do. Reavell’s Works........ ....-. | 18 34 — 16 Do. Gas Company, Holywells.. 2 37 — 10 | Do. Orwell Works...............++ | 12 32 Jo AD Do. Near Cliff Brewery............ | 0) 18 — 18 Do. Fison’s Works ..........--+++ 12 | 30 — 18 Do. Waterworks................0.++- | 25 27 — 2% Do. Stoke Uaupm yosee-ce-case sete 40 60 = 2).- Do. Waterside Works ............ 15 20 & 26 —5&—9 Do. South of Key Church......... 11 61 — 50 Do. St. Peter’s Works ............ 12 70 — 58 Do. @raniieldisayeeesccessees eee 10 I oes 2 —117 | ros VaCollevetStreaberecss nee 14 130 —116 Do. Gas Company, Patteson Rd. 14 90 — 76 Do. ID resell WOANS cucocaosauccsvaeue 23 113 i; — 90 | Do. Smart’s Wharf ............... 13 403 | — 273 | Do. Old Dock borings ............ Many below, — | —18 to —60 Do. New Dock borings, average do. — | 25 to —32 Rushmere jie Wee nkse asa eaters 82 114+ | — 382 Woolyerstone)*.. ah ana amen oan 95 105+ | -- 10 Botterman’s Bay i .scea.sec-cee ee seeer — — | Below —40 ! Includes Eocene beds and Crag also. A Vol. 69.] AGE OF THE SUFFOLK VALLEYS. 607 (d) Deben Valley.—The borings in this valley near Wood- bridge are more difficult of explanation. Of about fourteen well-sections recorded, ten are conformable with regard to the position of the top of the Chalk and Eocene beds, but one is anomalous. The explanation of this singular section was discussed by Mr. Whitaker and others,’ opinions being divided ; suggested causes were a Glacial channel, a huge Chalk solution-pipe, land- slipping, and trough-faulting. None were satisfactory, but the last seemed to be the best. ‘The following is the boring as recorded, the square brackets indicating the proposed grouping of the strata :— Trial boring for Woodbridge Waterworks Co., 1901. (Height above sea-level =18 feet.) Thickness in Depth in feet inches, feet inches. SOs Mere aa Pelion Auslenciacadslecwosncie ence eseeidetsevenelsehier 2 0 2 to) (SING Leis Ae aonnosedasnabaseocee seaodeas 4 6 6 6 Gravel and flints...................+- 3 0 9 6 Loamy sand (sandy loain)......... 4 0 13 6 Sandee evet iia. Sacaunmataneaeaeiese sek oy 6 16 0 PREM te GraVel\ tes. yscnnseh snnshasmtcedeeduet 3 5 19 5 Sand and shingle (loamy gravel). 4 0 23 5 Mottled sand (somewhat loamy). 6 0 29 5 Sand a shingle (fine gravelly : k p GENIN) 2, Mons Honbosenespncertonocenadee 3 5 ( Grey sand (dark-brown siltysand) 1 0 38 5 Fine sand (shelly sand)............ a 0 45 5 Fine sand, shingle, and Crag (Cees 4 (gravelly sand)... SPL eh inaciedse ts 60 i 106 0 953 feet. ] | Black mud (fine gravelly loam)... 1 6 107 6 | Crag with shells (shelly sand, i pRALELLn) ie wm cacle See meer ee nese 25 3 132 9 [Lonpon Cuay? { Claystone (septaria) ............... 0 9 133 6 nearly Blue clay (stiff grey clay) ......... 15 4 148 10 20 feet. ] | Sand and pebbles .................. 3 9 152 7 ( Dark sand (grey firm sand, slightly RESON INGIO en Mel OAM) inh avec aseseskoae deccecciseiecten Ce) 1590 *“ Beps? | Yellow’ sand and clay (brown nearly j Sercd Wa ee eRe LS ete ee eR age. 9 41 feet. | \) Blue clay (enrey)) seetaceseeeeeaeee 2 3 177 0 | Fine yellow sand (brown)......... 16 6 193 6 Cisunrize (hare athbnlds)) ee nedecnaraaeonaacocse ene CoRpCSnee Lane 55 6 249 0 The Chalk was thus reached at —175 feet O.D., while its surface in wells close by occurs at from —20 to —47 feet O.D. There is no evidence of faulting or similar disturbance of the beds anywhere in the surrounding area (faults are very rare in Suffolk, and when they occur are of trivial character), and in view of glacial distur- bances on a large scale seen in Suffolk valleys, it seems more satis- factory to regard the case as one of a buried glacial channel similar to those in the neighbouring valleys. It is noteworthy that a 1 Whitaker, 1903 (20) p. 26. 2 «Water-Supply of Suffolk’ Mem. Geol. Surv. 1906, p. 128. \ 608 MR. P. G. H. BOSWELL ON THE [Dec. 1913, channel of Drift was recorded by the Geological Survey higher up the valley at Naunton Hall.1 The portion labelled ‘Crag’ may be made up of ineluded Crag in the Drift, such as is often met with in South-Eastern Suffolk? but it was the Eocene beds that were the chief argument against the ‘channel’ explanation. ‘hese (if they are all Eocene, which is doubtful) appear to be im situ; but it is quite possible that they are not (large masses of disturbed and transported Crag, London Clay, and Chalk have been recorded in the Gipping Valley by Mr. Slater, in some cases preserving their natural sequence). That all this material may be mixed is somewhat confirmed by the anomalous sequence of beds found in the most recent boring at Woodbridge Waterworks (No. 1 below), although it is possible that the beds have been wrongly named. It is probable too, that Mr. Whitaker’s suggestion of slips into the channel (which need not then have been at ‘a goodly depth below sea-level’) may be correct, especially if the channel had been eroded by sub-giacial water-streams. In any case, it appears to me that the explanation of the phenomena by means of a buried channel is quite as justifiable as the assumption of a trough-fault ; and, more- over, such interpretation of the evidence brings this valley into accordance with the others. TABLE oF BoRINGS IN THE DEBEN VALLEY. Height | Thickness Chalk-sur face! | Locality. above O.D.| of Drift | referred to im feet. | im feet. | O.D. in feet. | | | | | IeElasketongl; tame etme tec tre earn 85 | 54 4 + 30 | Melton—Brewery ...-.-.2-...ceeeeee+- [es CDRS SIS Pe COIs me, lean armen | Do, = ANgypllnton, (GD) \iodsosonscoesdastnn 100 a 26) Sees eos IDO M2) Reems aden as a 15 5212 oe aol | Woodbridge—Hayward’s ............ 13 48 — 45 Do. Thoroughfare ......... 16 63 + — 47 | Do. IByamivereere serie 26 615 — 354 Do. Stun IBA ~ sooo4c0n5ccsne | Jo 52)+ — 19 Do. (CRIHIGIPIS: |. ogsoeecodasco: 77 52 + 25 Do. Waterworks (1) ...... 120 2 ee 28 | Do. Do. (Bayi aRe alate alts) 1932 See | Do. Gas-Works ............ 12 | 48 — 36 | | Do. Bredfield Road ...... ee 26 155 + — 29 | | Do. Castle Brewery ..... | 20 743+ — 644 | \Wvenlkabenmaenttelll ssencancndes Seoaceosoas00n | 8 63 + tS) * Mem. Geol. Sury. 1886 (11) p. 40. * The so-called ‘Crag’ is here nearly three times too thick for any known section or well-boring in the Red Crag. 3 Slater, 1907 (22) & 1911 (82). 4 Eocene beds and Crag may also be included. Vol. 69.| AGE OF THE SUFFOLK VALLEYS. 609 (e) Alde Valley.—The evidence in the much smaller valley of the Alde is naturally not so striking, but a comparison of borings at Saxmundham and neighbouring places serves to show, as Mr. Whitaker hints in the Survey Memoir on the Water-Supply of Suffolk, that here we have a hollow of Drift and Crag cutting through Lower Eocene deposits. It is not necessary for the present purpose to discuss the question as to whether the Crag which rests directly on the Chalk is a situ or not, for it is sufficient that Drift extends for a thickness of 103 feet, down to a depth of —3 feet O.l., whereas the usual level in the neighbourhood for the top of the Crag is about-+50 feet O.D. It is probable that the borings at Kelsale, higher up the valley, which show 115 and 106 feet of Drift eroding deeply into Crag, confirm the presence of the channel. The Chalk is dipping too rapidly in this extreme eastern part of the county for the channel of Drift to cut down into it. It is only to be expected that, if the channel, as well as the buttressing on spurs already described, is due to glacial action, the phenomena in this part of Suffolk, where the ice-sheet must have become attenuated, should be less well-marked than in the west. (f) Waveney Valley.—Finally, the probability of a buried channel in the Waveney Valley was suggested by the writers of the Geological Survey Memoir on the Halesworth and Harleston area. The Chalk crops out in the valley from Diss to Scole at about +60 feet O.D.; but two borings at Hoxne show Drift with (possibly reassorted) Crag material lying in a hollow of the Chalk, which was here met at —40 feet O.D. The boring at Kye appears to be connected with these two, but it is not easy to account for the Fressingfield boring at 152% feet O.D. reaching Chalk at —118 feet O.D. Indeed, this is the only case in Suffolk where a great depth to the Chalk is met with (Drift and ? Crag) which does not le in one of the valleys.” It is possible that a buried valley is here entirely masked by the Drift now forming the plateau. The levels of the top of the Chalk near Hoxne and Kye are :—Palgrave +105, Stuston +25, Diss +380, Scole +60, Bilingford +45, Wortham +110, and Thorndon +33 feet O.D. With reference to the Dallinghoo boring, which showed 79 feet of Drift, the material cut through being described by the Rev. R. A. Bullen,’ the late Prof. Seeley remarked that here we had another hidden channel; but this thickness of Drift is normal -for the plateau, and proves nothing. At Euston, in the valley tributary to that of the Little Ouse, running north-westwards from the watershed, a thickness of 224 feet of Drift was recorded, bringing the top of the Chalk to —140 feet O.D. Near by, the Chalk surface occurs at +60, 1 Mem. Geol. Surv. 1887 (12) p. 3. 2 But compare also the recent boring at Saham Toney (Norfolk), described by Dr. A. Strahan in the Summary of Progress of the Geological Survey for 1910 (1911) p. 75. * Bullen, 1901 (18) p. 285. 610 MR. P. G. H. BOSWELL ON THE [Dec. 1973, +137, and +146 feet O.D. It is also possible that there is a hollow in the Lark Valley near Lackford, but these north-westward flowing rivers connected with the Wash drainage are outside the area discussed in this paper. The thicknesses of Drift in all the well-sections in the county haye been compared, and all those over 100 feet examined. These latter were found to be on the higher parts of the plateau, where such a thickness would be expected, or in the valleys, where they showed deep channels in older beds. The conclusion then arrived at is, that in every valley of any size in Suffolk, a deep channel filled with Drift occurs. In some valleys: for instance, the Brett and the Gipping, two such channels appear to be in alignment (unless the one channel takes a very winding course, which is rendered improbable by the evidence of numerous borings on tlie sides of the valley). It will be noticed that these channels, together with those recorded in the Cam Valley, in the Fen district, the Stort Valley, Hitchin, and Yarmouth, form a roughly radiating series. Those which occur near the sea ( Brett, Gipping, Deben) are possibly separated from it by a sill or threshold; but, here again, they may take a circuitous course and maintain their depth to the sea, although the evidence is not at all satisfactory. At Ipswich, where we have a large number of borings, both in the town and in the surrounding country, it is difficult to understand why such a sill should not exist (see fig. 4, p-602). More borings are needed to outline the form of the channels accurately ; but, from those that have been put down, particularly on the sides of the valleys, the channels are seen to be of long narrow form, and in the area discussed all lie in a Drift-covered, recently-glaciated plain stretching to the sea. The data are not sufficient to enable us to draw with certainty the longitudinal profiles of these channels. There is good evidence in the district for believing that the county stood at a higher level in Glacial times ; but the evidence is rather against the view that the now- buried channels were carved out by ordinary river-action. There is no uniformity in the depth to which they are cut, as the following comparison shows :— Channel. Depth in feet recorded below O.D. Gllemstondei eek. oso ee a eee —347 iBrettenhanaerecenccccas sa. pene eee eee ee — 32 Fla dleiolpssarneceusasnccueaasiee eriseetncce moses — 40 Stowmarnrke bey wees sack screen eee ee — 5 ps wichysrai Ge cesta ee sacte. ce cneca bade ne seen —l17 Wioodlbrid commences eee se eaeee ie eicte Goan —176 TRAVEL BANG Gp tae tes ee me nee ae ne ata nae ae neat — 3 TEliomvie Shieh es ia Leena aor hier Si ee — 40 UL DS] 5.0) VNeP Seren SaaS ane Been ALi chore dine 82 — 140 Moreover, the finding of the rounded flints, unstained and unaltered, at the base of the Ipswich channel, points to pot- hole action, but not that of an ordinary open torrent. We do Vol. 69. | AGE OF THE SUFFOLK VALLEYS. 611 not yet know, however, whether a depth of over 400 feet (as at Glemsford) could be excavated by sub-glacial water. The presence of these channels helps to prove that the valley- system of to-day is older than the valley-glaciers which appear to have formed such deep hollows. It is interesting in this con- nexion to note that Dr. Emil Werth and others describe in detail similar channels due to the excavating action of sub-glacial water- streams which bubble up and emerge at the snout of the glacier.' These are termed Fohrden or Forden in Schleswig-Holstein, Fjiirde in Sweden, and Fjorde in Denmark (not to be confused with fiords). The characteristics of these Féhrden are their parallel or radiating arrangement; their long narrow form; their perpendicularity to the ice-edge and to the terminal moraine; their association with deposits of morainic character; the existence of a threshold or sill between them and the sea; and their occurrence on a recently-glaciated, comparatively-low country bordering the sea.” Besides their distribution as noted above, they have been studied in Kerguelen by the German Antarctic Expedition of 1901-1903.8 The occurrence of deep channels filled with Drift in Suffolk valleys, associated generally with mounds of glacial débris, morainic or glacieluvial gravels, and great masses of Boulder Clay, as well as with intense glacial disturbance, is certainly significant, and is worthy of further attention. It does not seem improbable that here we may have hollows analogous to the true Fohrden, described so graphically and in so much detail by Dr. Werth (indeed, paragraphs from the latter’s pen apply equally well to Suffolk conditions).* Dr. Werth, in a letter, tells me that he knows of no examples in North Germany filled entirely with Glacial Drift, but that the complete filling-in of Suffolk channels may be due to the fact that they belong to an older glaciation. Mr. F. W. Harmer has expressed the view that the ‘Cannon-Shot’ Gravels of Norfolk, with their spherical flints, may be due to the action of sub-glacial water-streams. VI. THrorericaL Questions AND GENERAL REMARKS. Sir J. B. Phear noted in 1856 that the Gipping was a dip- stream flowing south-eastwards from the Chalk escarpment, which runs generally from south-west to north-east, and examination of 1 These ‘submarine wells’ of fresh water emerging as fountains in the Greenland fjords were noted as far back as 1877 by Henry Rink (‘ Danish Greenland: its Peoples & its Products’ London, 1877, pp. 50, 360-63). Such fountains of fresh water burst out with great violence on a sudden fall in the level of marginal lakes of the Greenland ice-sheet. See also W. H. Hobbs, 1911 (80) pp. 175 ez seqg. 2 Werth, 1909 (26, 27, 28) & 1912 (36), * Td. 1908 (24) pp. 180-48. 4 For references to further work on Fohrden, see the authors quoted in Werth, 1908 (24) & 1912 (36), as also K. Olbricht, ‘ Die Exarationslandschatft ” Geol. Rundschau, vol. 1 (1910) p. 59 and references there. 612 MR. P. G. H. BOSWELL ON THE [ Dec. 1913, the map of Suffolk (Pl. LIV) shows that the Suffolk rivers are largely dip-streams, although their direction changes from east- north-easterly in the north of the county successively to easterly, south-easterly, and southerly in the south of the county, in con- sequence of the change in strike of the Chalk. It seems quite likely that many of them are beheaded consequents belonging to a larger drainage-system, which included originally the rivers now reaching the Wash.’ In the area (south-east of the watershed) with which this paper deals, the form and direction of the rivers and their tributaries would seem to suggest some amount of capture here also, possibly behind an old Kocene escarpment; but the country is now so plastered with Drift that it is almost impossible to obtain evidence of any kind for or against capture. Many of the subsequent tributaries are well developed; but, if capture did take place, the process does not appear to have gone very far. In the case of the Stour, there is a possibility that the river from its source to the Wixoe bend (see Pl. LLY) may be the captured head- — waters of the south-eastward flowing consequent stream on which Colchester stands—the Colne. The portion from Wixoe to Long Melford would be subsequent, and the Sudbury portion another consequent, and so on. ‘The watershed between the Colne head- waters and the Stour is only some 80 feet above the river-levels (which are equal, the Stour at Wixoe being 170 feet O.D. and the Colne at Great Feldham 164 feet O.D.), and consists of Upper Boulder Clay and Glacial Sand, there being barely a mile of land between the two valleys. The Drift round about, as shown by well- borings, ete., is often more than 8U fect thick. The same kind of process may have gone on in the more eastern part of the area, but may have been even less developed. The general rectangularity, which is apparent independently on both contoured maps and uncontoured geological maps, of the course of the Brett Valley (Cocktield to Lavenham consequent, Lavenham to Nedging subsequent, and Nedging to the Stour consequent again), of the Deben Valley (Debenham to Rendlesham consequent, tendlesham to Woodbridge subsequent, and Woodbridge to the sea consequent again), and possibly of the Alde Valley, is rather significant. The map certainly suggests that the Butley Valley and the upper portion of the Deben Valiey were once united, but here, as elsewhere, owing to the mantle cf Drift, which is frequently loam, gravel, and sand like that of river-deposits, neither ‘gaps’ nor river-gravels can be detected. From its very nature, the district does not lend itself to the usual manner of treatment of river- development, questions. The Gipping Valley appears to be purely a consequent one, but it is noteworthy that the watershed between the Gipping (or Orwell) and the much smaller Deben is actually in the east of the town of Ipswich, near the Asylum. Here the small tributary -valley which passes eastwards through Foxhall, Brightwell, etc., originates. 1 Davis, 1895 (15) p. 144. s Vol. 69. ] AGH OF THE SUFFOLK VALLEYS, 613 The Drift-deposits (Upper Boulder Clay and at times Glacial Sand and Gravel) lie in the subsequent and consequent portions of the valleys alike. Where these valleys are winding in character, the sinuosity must have been developed before the oncoming of the Upper or Great Chalky Boulder Clay. It is quite evident that the small streams meandering in these wide valleys at the present time cannot have carved out such features.1_ The present rivers, as insisted on frequently by Mr. F. W. Harmer with especial reference to Norfolk,’ are out of all proportion to the valleys which they occupy. We have seen that such valleys are certainly either pre- Glacial or early Glacial in age. When, then, was this somewhat mature, low-graded system developed? During the Pliocene Period, the tectonic wave-like movements of the land that now forms East Anglia resulted in a gradual rise southwards and depres- sion northwards, and were doubtless adjustments following the strong Miocene folding of the South of England and the Continent. Reasoning from the boulders found in the Red Crag (London Clay débris, Hertfordshire puddingstone, sarsens, Chalk-flints, masses of Kellaways Rock crowded with Rhynchonella socialis, other Jurassic rocks, Bunter pebbles, granites, etc.) the drainage seems to have been towards the east; but, at the end of the Crag Epoch, the drainage appears to have been towards the north or north-west, if we are to believe the Continental geologists, who see in the mica with which the ‘ Chillesford-Clay river’ is loaded, material derived from the Ardennes or even farther south.* The Butley, Alde, and more northerly rivers cut through these Chillesfordian Beds: therefore, the present valley-system must have been developed in a doubtless long period, which intervened between the Chillesfordian age and the time when the Glacial Sands and Gravels which lie beneath the Upper Boulder Clay were deposited. As Prof. J. W. Gregory, Mr. Jukes-Browne, and others have pointed out,* the country at the close of Pliocene time must have had an appearance very similar to that which it now presents. The Cretaceous escarpment had by then retreated almost to the position which it now occupies, and was a well-marked feature, as illustrated by the manner in which the Glacial deposits were banked against its front.2 The outlines of the present drainage would at this time have been etched upon the south- eastward sloping peneplane. Increasing in power, the rivers graded their valleys and some amount of capture may have taken place, possibly behind a secondary HKocene escarpment. Vertical corrasion gave place to lateral corrasion, and the rivers developed their present wide and open valleys (see fig. 5, p. 614), and as 1 The average annual rainfall of Suffolk for 1862-1902 was 24:5 inches. 2 Harmer, 1909 (25) pp. 121 et segq. 3 Harmer, 1902 (19) p. 447; but see also C. Reid, ‘ Pliocene Deposits of Britain’ Mem. Geol. Surv. 1890, p. 189. * Gregory, 1894 (14) p. 102; Jukes-Browne, 1911 (31) p. 428 (also earlier ~ works). ° See also Harmer, 1909 (25) p. 114, etc. Q.J.G.8. No. 276. 28 614 | [ ‘99UO [OVS UL [OAOT-VOS SOJVOTPUT OUTT-svq ot ‘UMOTY JOU SI Sor] Jo Odevgs Jouxo or ynq ‘spouuLYO poland Jo y4dop tl falas [PUL oUT[-osug Oty ‘il : IU a} q 1} nq “sy (PPE TERN AO) GOT puv uorjisod oy} oyworpUr soul] pojjop ety, *(1) AOALt OY} Fo UOTOeAIp oT 0} ivjnorpuod.od rove ouw suorjoes ory, | <--3+-> me) si : “MWS'S ¥ a edeus 32 Aor A oply ool , O01 “AAS AA ‘ANA espliqpoom ye AsV, ueqeq Yi a /08 2 ; Z ] ,OOr {OO “TN “MS yormsdy ye Aaye, durddiy ) haa j,OOT ‘a iaeR * “MA Hes uopheyQ ye Aoiep surddry jooz ‘aN “MNS Aimqpng ye Aojje~ 3003S (“pozuozrloy a7 20109 UDy aro waygne wo “Q20f 00D =youw T+ ywaaygwaa fF opr 7 =soysur F ‘qoruozru0y +: saynay) ‘shappna yjoffng fo sw0r928-ss0.1gQ —*g “SLT , Vol. 69. ] THE AGE OF THE SUFFOLK VALLEYS. 615 the streams became sluggish, the wide valleys took their present rather sinuous courses. (It is to be noted that the rivers themselves also meander independently through their alluvial flats, often resting upon Drift in the sinuous valleys.) The valleys are of the shallow trough-like type \HH_y described by I. C. Russell.* Thus, before the oncoming of the district-glaciation, the valley- system had reached .a fairly mature state, and it is possible that had not this development been now arrested, further grading and capture might have resulted. The great outwashes of sand and gravel from the ice-sheets on the north-west spread over East and South-East Suffolk, extending in places down into the valleys, only to be excavated again for the most part by the streams of water from the same source taking advantage of the channels to the sea which the valleys provided. Thus, the fact that the greater number of the valleys are cut through such sand and gravel, but that some- times the deposit flows over into them, would be accounted for. The oncoming ice-lobes themselves would take advantage of the hollows already made in the land-surface, and in an attempt to straighten out the winding valleys. would buttress themselves upon and over-ride each successive projecting spur. Upon the recession of the ice, Boulder Clay was left in all the valleys as well as on the plateau, and was covered by the torrential gravels so well observed in the Suffolk valleys. The high-level glacieluvial gravels also would have been laid down at this time. In fact, it appears that the streams fed by the melting ice were overloaded with detritus, and they deeply filled their valleys with debris, as described by Russell in the glacier-valleys of the Cordilleran region, ” only, however, to resume the work of excavation and leave the river-terraces and higher-level gravels as evidence of former conditions. It is noteworthy in this connexion that there is a broad development of terrace (a mile and a half wide) at Ipswich, where the valley narrows and takes a sharp bend; similarly also at Sudbury and Woodbridge. (Hence, no doubt, the early settle- ments and establishment of the various Suffolk towns.) The top of the Gipping terrace roughly follows the 50-foot contour in the lower part of the valley, but rises gradually to the 100-foot contour near Stowmarket: that is, it maintains a fairly constant elevation above the present level of the river. Buried peat and freshwater deposits found in the bed of the Orwell estuary for a length of 7 or 8 miles, and outside the Deben estuary,’ prove a subsidence since Glacial times of at least 30 feet. Mr. Clement Reid states that the submergence amounts to something between 60 and 80 feet, all through East Anglia. From the terrace-levels the subsidence seems to have been general over the area—there is no evidence of tilting—and it is this subsidence which has buried the lower 1 Russell, 1898 (17) p. 151. ° Thid. pp. 234 & 284; seealso G. W. Lamplugh, Q. J. G. S. vol. Ixviii (1912) yp. 251 (discussion). 3 Taylor, 1875 (6) p. 82, and 1882 (9) p. 573. + Reid, 1913 (88) p. 22. 282 616 MR. P. G, H, BOSWELL ON THE [ Dec. 1913, portions of Suffolk rivers and turned them into wide open estuaries. The navigation-channels in these estuaries give a clue to the position of the river itself. The rivers, reduced in bulk, with a lower gradient,’ have deposited small flood-plains of alluvium between their old terrace-outlines, and are now engaged in mean- dering to and fro in these alluvial flats. Where they touch their old terrace, villages have been built. As previously pointed out, the small streams now occupying these wide open valleys are quite out of proportion to them, and either indicate a good old age (which is not altogether supported by other evidence), or that there has been some interference with their development: namely, that caused by the ice-sheet and valley-glaciers, and a depression which followed the glaciation. Minor changes have taken place since this last subsidence of the area, and are taking place to-day, being mainly due to the southward tidal drift down the Suffolk coast. This, by damming up river- mouths with shingle, and permitting silting-up to take place, is either tending to form broads, as described by Prof. J. W. Gregory for Norfolk, or diverting the mouths of the rivers southwards. Such deflection is exemplified by the classical case of the Alde, but can be observed to be in process with smailer streams, as well as with the Orwell and Deben. VII. Concrustons, (1) The valley-system of Southern and Eastern Suffolk is radiating in character from the watershed parallel to the Chalk escarpment in the north-west, the rivers being largely consequent but partly subsequent in form. The valleys are wide and graded, all angu- larities having been worn off, and are carved out of all proportion to the size and number of the streams that now occupy them. (2) On the evidence of the excavation of Red, Norwich, or Chillesford Crags, respectively, by the rivers, the valleys (though they may have been etched earlier) are post-Chillesfordian in age. By analogy with the Waveney and Norfolk rivers, they may be younger than the Contorted Drift (Lower Glacial). (3) Upper Boulder Clay lies persistently in the valleys, there is Glacial buttressing on projecting spurs, and in each main valley there is a channel filled with Drift. On these three counts the valley-system is older than the Upper Glacial deposits. (4) There is a similarity of form and origin between the buried channels and the Continental Fohrden, which are admittedly due to sub-glacial drainage. (5) The present river-system is recovering from a state of arrested development, due to the glaciation of the area (and conse- quent overloading of the valleys with débris) and the subsidence which followed it. 1 That of the Gipping is, in its portion from Haughley to Needham, 1] in. 718, and in its lower portion (Needham to Ipswich), 1 in 1003. 4 Vol. 69.] AGE OF THE SUFFOLK VALLEYs. 617 In conclusion, I have to express my sincere thanks to Prof. W. W. Watts and Mr. W. Whitaker for reading the manuscript and for many helpful hints ; to Dr. J. W. Evans for German references, etc. ; to Dr. A. Strahan, Director of H.M. Geological Survey, for facilities in obtaining recent well-records; to Mr. F. W. Harmer for his trouble in discussing these questions frequently with me, and for his assistance and direction in Norfolk field-work ; to Mr. Thomas Miller, C.E., Mr. C. W. Oldham, and Mr. T. J. Warner, of Ipswich, for records of new borings ; and particularly to my friend Mr. George Slater, of Ipswich, for permission to use freely his admirable material on Kast Anglian glaciology. VIII. Breriocraprny. (1) 1856. Sir J. B. Porar.— On the Geology of some Parts of Suffolk, particularly of the Valley of the Gipping’ Trans. Cambridge Phil. Soc. vol. ix, pt. iv, p. 431. : (2) 1867. ¥. W. Harmer. On the Existence of a Third Boulder-Clay in Norfolk’ Q.J.G.5. vol. xxiii, pp. 87-90. (3) 1868. S. V. Woop, Jun., & F. W. Harmer.— On the Glacial & Post-Glacial Structure of Norfolk & Suffolk’ Rep. Brit, Assoc. (Norwich) Trans. Sect. p. 80. (4) 1869. S. V. Woop, Jun., & F. W. Harmer. On a Peculiar Instance of Intraglacial Erosion near Norwich’ Q. J. G.S. vol. xxv, p. 259. (5) 1872. S. V. Woop, Jun., & F. W. Harmer.— An Outline of the Geology of the Upper Tertiaries of Hast Anglia’ pp. 1i—xxxi, vol. iii (Supplement) ‘ Crag Mollusca’ Monogr. Palwont. Soc. 1872-74. (6) 1875. J. HE. Tavtor.— Discovery of a Submerged Forest in the Estuary of the Orwell’ Rep. Brit. Assoc. (Bristol) Trans. Sect. P: 82. (7) 1877. S. V. Woop, Jun., & F. W. Harmer.— Observations on the Later Tertiary Geology ‘of East Angha, &e.’ Q. J.G.S. vol. xxxiii, p. 74. (8) 1881. W. Wuitaxcer, F. J. Bennett, & J. H. Buaxe.— Geology of the Neighbourhood of Stowmarket ’ (Quarter-sheet 50 S.W.) Mem. Geol. Surv. (9) 1882. J. H. Taytor.— Submerged Forests on the Suffolk Coast’ Geol. Mag. dec. 2, vol. ix, pp. 573-74. (10) 1885. W. Wuitaxer & others.— Geology of the Country around Ipswich, Hadleich, & Felixstow’ (Quarter-sheets 48 N.W. & N.E.) Mem. Geol. Surv. (11) 1886. W. H. Datron’ & W. WuitaKEer.— Geology of the Country around Aldborough, Framlingham, Orford, & Woodbridge’ (Quarter-sheets 49 8. & 50 S.E.) Mem. Geol. Surv. (12) 1887. W. Wuitaxer & W. H. Datton.—‘ Geology of the Country around Halesworth & Harleston ’ (Quarter-sheet 50 N.E.) Mem. Geol. Surv. (13) 1890. W. WuiraKkEeR.— On a Deep Channel of Drift in the Valley of the Cam (Hssex)’ Q. J. G.S. vol. xlvi, p. 333. (14) 1894. J. W. Grecory.— The Evolution of the Thames’ Nat. Science, vol. v, p. 102. (15) 1895. W. M. Davis.— On the Development of certain English Rivers’ Geogr. Journ. vol. v, pp. 127-46. (16) 1897. Rev. A. Irvine.‘ On the Geology of the Stort Valley (Herts & Essex), &c.’ Proc. Geol. Assoc. vol. xv, p. 224. (17) 1898. I. C. Russpirt.— River-Development, as Illustrated by the Rivers of North America’ London & New York. (18) 1901. Rev. R. A. Burten.—‘ Note on a Well-Section at Dallinghoo (Suffolk) ’ .J.G.S. vol. lvii, p. 285. (19) 1902. F. W. Harmer.— A Sketch of the Later Tertiary History of East Anglia’ Proc. Geol. Assoc. vol. xvii, p. 416. (20) 1908. W. WuiTaKER.— On some Well-Sections in Suffolk’ Q.J.G.S. vol. lix, p. 33. (21) 1906. W. Wuitraxer.— The Water-Supply of Suffolk’ Mem. Geol. Surv. (22) 1907. G. StarEr.— Excursion to Ipswich & Claydon’ Proc. Geol. Assoc. vol. xx, p. 186. (23) 1908. W. Hirn.— ‘On a Deep Channel of Drift at Hitchin (Hertfordshire) ’ Q.J.G.S. vol. lxiv, p. 8 (also references there given). 618 MR. P. G. H. BOSWELL ON THE [Dec. 1913, (24) 1908. E. WertuH.— Autbau & Gestaltung von Kerguelen’ (Deutsche Siidpolar- Expedition, 1901-1908) Berlin, vol. ii, pt. 2, pp. 130-48. (25) 1909. F. W. Harmer. The Pleistocene Period in the Eastern Counties of England’ Geology in the Field, Proc. Geol. Assoc. Jubilee vol. p. 103. (26) 1909. EK. Warta.— Das Hiszeitalter’ Leipzig, p. 38. (27) 1909. EK. Werra.— Zur Entstehunge der Foérden’ Zeitschr. Deutsch. Geol. Gesellsch. vol. 1xi, pp. 401-404. (28) 1909. E. Werru.— Fjorde, Fjarde, & Féhrden’ Zeitschr. f. Gletscherkunde, vol. ili, pp. 346-58. (29) 1910. F. W. Harmer. The Glacial Deposits of Norfolk & Suffolk’ Trans. Norf. & Norwich Nat. Soe. vol. ix, p. 108. (30) 1911. W. H. Hopss.— Characteristics of Existing Glaciers’ New York. (31) 1911. A. J. Joxus-Browne.—‘ Building of the British Isles’ 3rd ed. London. (32) 1911. G. Starer.— Excursion to Ipswich’ Proc. Geol. Assoc. vol. xxii. p. 11. (83) 1912. P. G. H. Boswrerin.— Report of an Excursion to Ipswich & the Gipping Valley’ Proc. Geol. Assoc. vol. xxiii, p. 229. (84) 1912. Rev. E. Hinn.— The Glacial Sections round Sudbury (Suffolk)’ Q.J.G.S. vol. lxviii, p. 23. (85) 1912. W. Hin. Report of an Excursion to the Hitchin & Stevenage Gap’ Proc. Geol. Assoc. vol. xxiii, p. 217. (36) 1912. KE. Wertu. Zur Fohrdenfrage’ Geol. Rundschau, vol. ili, pt. 3, p. 164. (37) 1913. P. G. H. Boswern.— Notes on the Chalk of Suffolk’ Journ. Ipswich & District Field Club, vol. iv, pp. 17-26. (38) 1913. C. Rurp. Submerged Forests’ Cambridge. EXPLANATION OF PLATES LIV & LY. Puatse LIV. Map of Suffolk, showing the river-svstems and the position of the top of the Chalk, on the scale of 8 miles to the inch, or 1 : 506,880. Puate LV. [All figures on the scale of 1 inch to the mile, or 1 : 63,560. ] Fig. 1. Contoured map of the Gipping Valley, showing projecting spurs where disturbance of beds occurs. 2. Contoured map of the Brett Valley, showing the same phenomena as fig. 1. 3. Contoured map of the Stour Valley (upper part), showing the same phenomena as figs. 1 & 2. Discussion. Mr. F. W. Harmer said that he had listened with great pleasure to the paper, the subject of which was both interesting and important, and he congratulated the Author very cordially on the way in which he had worked it out. For many years the Eastern Counties had been too much neglected by field-geologists. It was, therefore, the more gratifying that at Ipswich, which had been lately so much to the front, the Author and his coadjutor, Mr. Slater, were setting themselves seriously to carry on the work of which the speaker’s old friend and master, the younger Searles V. Wood, laid the foundations more than fifty years ago. That, in some matters of detail, the latter’s conclusions might need reconsideration would not come as a surprise, but to those who could remember the condition of Kast Anglian glaciology in 1860, the marvel was that they required so little. The speaker had long doubted, for example, as the Author did, whether the Contorted Drift of the Cromer coast ever reached as Ouart. Journ. Geol. Soe. Vol. LXIX, PL. LIV. YSTEMS AND THE POSITION OF THE Top OF THE CHALK. +Botesdale Eteoyaan +Mendleshoan sfoo r+) | Ub Yi Blaschall- ae E JOnford Ness =204 BNE Lg “ i: Hollesley ff o_o —_ Limit of Lower Londan Tertiaries (shaded tn) | j Approximate! : 3 & : +200 ,—— Above sea-level l(ntour Ii - iirattord: Nieeekle , >» Ly —-—«—-—x Sea-level for eee cate insane 7O2. Z i x : ee Om SI pee enti evel top of the The small figures indicate the level of the | Chalk surtace referred to 0.D.(measured in te) Scale ales | 8 miles to I inch. Weller & Graham L'@ Litho,London : Quart. Journ. Geol. Soc. Val. XIX, PLTAV. MAP OF SUFFOLK SHOWING THE RIVER-SYSTEMS AND THE POSITION OF THE Top OF THE CHALK. TT a BNaveney | iY L | Paketield Sirs ‘mere 1 Si «es ‘\ Harlestore / \ A\ Ae eer : Waveney, ars a\ \ Hele swor eee SThe. x +Botesdale 4 \. \ +e | fi b ny eae Ty Li Mp | lf Naa eal I! eae) | | vie oi | SE 4 Mendleshem fed | aA Lore i ig aeeny nepest, 04 KY Fina Biidcburgt | -300 7 | I / Jesnttargh Needham Uy Marker Py \Glautentirm Re loan cathedral] 4 Thitlexs \- Of¥or y - Norah | # Orford Nese ston om ! e 1 |e Mlakentycin j Se Nea é go D Ye, | mney Ore “ 4, 4 | Sadia de, 4a { + Churches y i} 7 Levon, write rd Sat evingtore f - County boundary « ¢Bentlesr = Y) Limit of Lower London = 2 Ae aT hens io 4 Tortiaries (shaded tn) | = Praga} or : = shoter \ = S se 4 RMB sonra 6 WN: i aE Pgie : | I a I ) ees The small figures trulicate the level of the Le — os Chalk surface pefirred. tm 0.D.(measured in fie Scale $1. $44 8 4 piles B males io I inch | _ Colchest4 Weller &Grahor U4 Lijho,London ih v Vol. 69. ] AGE OF THE SUFFOLK VALLEYS. 619 far south as Wood supposed. Taken as a whole, however, Wood’s foundations were well and truly laid, and his successors may safely build on them. The question of the origin of the valley-system of East Anglia should be studied as a whole, and over as wide an area as possible. If it were possible to ascertain the conditions obtaining in one part of the region, it would not be unreasonable to draw conclusions as to what was going on at the same time in another. The facts to be observed in Norfolk, where the evidence was clearer, might therefore throw light on those adduced by the Author from the sister county. In the speaker’s opinion, East Anglia was twice invaded by ice; and first from the north, by the Great Scandinavian glacier. To this invasion was due, not only the Contorted Drift of the remark- _ able and abrupt ridge which crosses the north-eastern portion of Norfolk from west-south-west to cast-north-east, attaining a maximum thickness of 300 feet, but also the uncontorted beds of brick-earth equivalent to it which occur over the lower and flattened region towards Norwich. The latter, the speaker considered, repre- sented the moraine profonde of the North-Sea ice during its maximum extension; the former (the contorted part) a terminal moraine at some stage of its retreat. Now, it seems clear that when the North-Sea ice crept over the country from the Cromer coast to the latitude of the Waveney Valley and beyond, the present valley-system of Hast Norfolk could hardly have been in existence: any pre-Glacial elevations then existing would have been levelled down by the ice, and any pre- Glacial depressions levelled up, or filled in by the morainic detritus brought by it. Moreover, the North-Sea Boulder Clay never occurs ° in this region as a valley-deposit ; on the contrary, the valleys, as, for example, those of the Yare and Wensum at Norwich, and of the Waveney at Beccles, are distinctly shown to have been cut out of it. The second invasion, possibly separated from the first by a con- siderable interval, was that of the great inland glaciers from the north-west, to which the Chalky Boulder Clay, with its Neocomian and Jurassic detritus, was due. The latter not only overspreads the higher ground, but, as we all know, wraps the sides of the present valleys, descending to the bottom, sometimes considerably below sea-level. The excavation of the Norfolk valleys took place, therefore, after or during the retreat of the North-Sea ice-sheet, but before the deposition of a part at least of the Chalky Boulder Clay. It may have been due, not improbably, to the action of torrential water during the retreat and melting of the ice of the first glaciation. The Author had found similar conditions in Suffolk, as Wood ° and the speaker did when they were mapping the county in the sixties; but here the relation of the Chalky Boulder Clay to the North-Sea Drift is not so clear, owing to the absence of the latter from a great part of the county. This subject was dealt with in a paper which the speaker read before the Society in 1866. 620 THE AGE OF THE SUFFOLK VALLEYS. [ Dec. 1913, He considered that there remained much work still to be done in; the district im question. The detailed investigation which Mr. Slater and the Author were making could not fail to bring to light many new and interesting points. The Rey. Epwry Hitz said that he was pleased that this work had been taken in hand by a worker possessed of such qualifications. He entirely agreed with the view adopted as to the age of this valley-system; and he was not without hope that indications of earlier stages might yet be found. Further light on the buried channels was to be wished for, but there were obvious difficulties in the way of obtaining the information desired. The AvrHor, in reply, agreed entirely with Mr. Harmer’s con- clusions, but thought it best to use caution in reasoning by analogy. Lack of time prevented the fuli discussion of the extent of the buried channels of Drift. It was possible that the hollows ended abruptly, as would be expected if they were eroded by sub-glacial water-streams. If the channels were continuous to the sea, their courses would be difficult to follow, and must be somewhat sinuous, departing from the present valleys. With reference to the well- borings, a4 maximum of facts was recorded, and a minimum of conclusions drawn, great caution being necessary in the inter- pretation of the records. MReasons for the belief that the Contorted Drift does not occur in Southern Suffolk were given briefly in the paper. Inconelusion, the Author thanked the Fellows for the reception accorded to his paper. é Vol. 69.] PETROLOGY OF THE KALGOORLIE GOLDFIELD, 621 27. On the Purrotoay of the Kateoortrr Gorprrenp (WaEsTERN Australia). By James Attan Tuomson, M.A., D.Sc., F.G.S., Palzontologist to the Geological Survey of New Zealand. (Read May 7th, 1913.) Contents. Page eat rOcluCtlomberensn ie sacs shes ncese csc teas ack comtuionecssmeccaecdaees’ 621 PE stomicaleievilewernss: aac atessaieee cece anes tos scene ses secu a0 624 le Weseriptiverketroona pity ws. ccreceacs) | micropegmatite (albitized | | greenstones) and schistose | representatives. L { Quartz-andesite. ——— Se fC tic. (c) Bleached greenstones with | micropegmatite and quartz- sericite-carbonate-schists. | F. Porphyrites. Porphyrites. | Porphyrites (?). | G. Albite-porphyries. | Albite-porphyries. | Felspar-porphyries. Mr. H. B. Corbin! was the first to doubt the sedimentary origin of the graphitic schists. He showed that certain supposed fossils were only pyritous nodules, and explained the slaty rocks as due to the contact-alteration of a porphyry by a ‘diorite’-dyke. His explanation, however, did not gain acceptance, and for twelve years the views put forward by Prof. Kemp held the field. In 1902 the Geological Survey of Western Australia published a map of Kalgoorlie by Mr. A. Gibb Maitland & Mr. W. D. Campbell, + “Notes on the Graphitic Slates & Associated Rocks in the Kalgoorlie District’ [& Discussion thareon] Trans. Roy. Soc. 8. Austral. vol. xxii (1898) pp- 72-75. ’ Vol. 69.1 PETROLOGY OF THE KALGOORLIE GOLDFIELD. 627 THE Rocks or KALGOORLIE. Gizson, 1911. Simpson, 1902. Harlier determinations. Ancient sediments. Older sediments. - | Conglomerates (Chewings). Fine - grained amphi- ) bolites (older green- stones). | vamhipolives’ tie and | their derivatives (in part). Cale-schists. Peridotites. Serpentines. Talc-schist (Maitland). Basic amphibolites. a) eae (Kemp). 5 | cece (Goczel, Card, Schmeisser, | Felspathic and acid Campbell). | f amphibolites. | Amphibolites and es Quartz-diorite (Watts). 5) r their derivatives Dredly: eS | (an part). — } ae | | ne fAcid eruptives (Card). | | i Basic — eruptives . (Rickard). r Quartz-diabase. , ) Deen(ioaren): | | ae | Quartz-andesite : L (Judd). J J i) |e ao SALTS SAGE Te es GiGi oas UT MES toe ne oer on i ar | a SaaS | Porphyrites. Porphyrites. Porphyrites (Campbell). | Felspar-porphyries. _ Kelspar-porphyries. Soda-felsite (Maitland). Felspar-porphyry (Card). Felsite (Campbell). on the scale of 10 chains to an inch (8 inches to a mile). The classification on which the map was based was as follows :— Recent superficial deposits. Dry blown patches. Laterite (ironstone conglomerate). Slates and schists. Quartzites and graphitic slates. Felsite (?). Amphibolite, massive (with hornblende), Do. do. (with chlorite). Do. do. (with actinolite), Do. foliated. Porphyrite. Mica-schist [transmuted porphyrite (?)]. Peridotite. 628 DR. J. A. THOMSON ON THE [Dec. 1913, In this map, the jasper-reefs were coloured as quartzites, being evidently therefore considered as sediments, and an extraordinary number of ‘ felsite -dykes were shown accompanying the jaspers. The peridotite-intrusion in the ‘ North End’ was not recognized, and the distinctions made among the amphibolites did not corre- spond to any very clear natural divisions in the rocks themselves. Consequently, the publication of the map had little or no influence in directing mining operations, more particularly as no explanatory memoir accompanied it. The rocks collected during the preparation of the map were examined and described in the same year by Mr. E. 8. Simpson’ in a short but concise paper, illustrated by numerous chemical analyses. The rocks were classified as follows :— I. Amphibolites and their derivatives (inassive greenstones, chlorite- schists, massive and foliated siderite-rocks). Helspar-porphyry. II. Newer eruptives , Porphyrite. | Peridotite. III. Older sediments. IV. Newer sediments. Chemical:—Salt, travertine, siliceous sinter, and laterite. Mechanical:—Sand, clay, and ironstone-gravel. That writer’s treatment marked a great advance in Kalgoorlie petrology, not only because of its comprehensive character, but also on account of the importance conceded by it to the amphi- bolites. Dr. Vogelsang,” who had previously made a study of the rocks of other Western Australian goldfields, had suggested the derivation of the amphibolites occurring in them from diahases, and Mr. Simpson applied this explanation to those of Kalgoorlie, pointing out that they were too poor in silica to be termed diorites. He further recognized the close connexion between the amphibolites and the greenstones, rejecting Mr. Card’s explanation of the latter as altered granites, a view which the analyses abundantly disproved. His failure to distinguish between the older and the younger amphibolites and greenstones may probably be put down to lack of opportunity of studying the field-relations in sufficient detail. The differences of interpretation on some points between Mr. Simpson and myself are fully discussed below. Until quite recently, subsequent authors (Krusch, Lindgren, Maitland, etc.) have, in general, followed Mr. Simpson; but Mr. T. A. Rickard,’ writing about the same time, quoted a determination of the dominant rock by Prof. J. W. Judd as a ‘highly-altered quartz-andesite,’ a view that might easily be taken after study of 1 «Notes from the Departmental Laboratory: Rocks of Kalgoorlie’ Bull. Geol. Surv. W. Austral. No. 6 (1902) pt. 2, pp. 62-79. 2 In K. Schmeisser, ‘Die Goldfelder Australasiens’ Berlin, 1897, p. 45 (English transl.: The Goldfields of Australasia, London, 1898, pp. 63-83). 3 «The Veins of Boulder & Kalgoorlie’ Trans. Am. Inst. M. E. vol. xxxiii (1903) pp. 574-75. ’ Vol. 69.] PETROLOGY OF THE KALGOORLIE GOLDFIELD. 629 enly a few specimens of the more obscure greenstones. Dr. L. J. Spencer’ cast some doubt on the derivation of the lode-matter from an amphibolite, being deceived by the thorough-going chemical alteration which the bleached greenstones and ores have undergone. ‘No hornblende was detected on any of the British Museum specimens [of telluride-ores], and in published analyses (Simpson, 1902) of these rocks the small amount of magnesia in the portion of the rock insoluble in hydrochloric acid indicates that not much, if any, hornblende can be present. Bands of hornblende-schist. are no doubt sometimes present in the sericite-schist. Much confusion between observed fact and theory has been occasioned by ‘the attempts of various authors to explain the origin of these schists.’ (Op. cit. p. 281, footnote.) During 1909-10, while Dr. Maclaren and myself were engaged in mapping the field, geological work was also being carried on by Mr. C. O. G. Larcombe, of the Kalgoorlie School of Mines, and Mr. C. G. Gibson, of the Western Australian Geological Survey. A limited exchange of views took place, and the resulting classi- fications * show, in consequence, some approximation to each other (see Table, pp. 626-27). Mr. Gibson has not yet presented the petrographical details that led to his conclusions, but it may be -noted that he failed to recognize the original rocks from which the ataphibolites were derived, while correctly assigning the greenstones to quartz-diabase. Mr. Larcombe dealt mainly with the rocks of “The Mile,’ and, in consequence, has failed to realize the intrusive nature of the quartz-dolerite, which he terms ‘ quartz-andesite.’ Neither of these writers has recognized the albitization of the greenstones, nor the close relationship between the albite-porphyries and the quartz-dolerites. III. Duscrrprive PErroGRAPHyY. Through the kindness of Mr. A. Gibb Maitland, Director of the ‘Geological Survey of the State, all the rock-specimens and micro- scopic sections of Kalgoorlie rocks in the Survey collections were placed at my disposal. By this means it has been possible to identify the rocks of which analyses had previously been published, and to use these analyses in connexion with the classification here adopted. Including the Survey collection, about 500 thin sections have been examined in the preparation of this paper, this apparently excessive number being necessitated by the great variations which the metasomatized quartz-dolerites and peridotites display, and by the lithological resemblances between altered rocks of very different origin. Obviously, for purposes of brevity and clearness, only the more conspicuous types can be described here, and preference 1 ‘Mineralogical Notes on Western Australian Tellurides: the Non-Existence of “ Kalgoorlite” & “ Coolgardite” as Mineral Species’ Min. Mag. vol. xiii (1902- 1903) pp. 268-90. 2 C. G. Gibson, ‘ Notes on the Principal Geological Features of the Kalgoorlie Goldfield’ Ann. Rep. Geol. Surv. W. Austral. for 1910 (in Ann. Rep. Dept. Mines, W.A., published 1911) pp. 115-23 and map; C. O. G. Larcombe, ‘The ‘Geology of Kalgoor lie (Western Australia) with special reference to the Ore- Deposits’ Proc. “Austral, Inst. M. E, vol. v, No. 2 (1911) pp. 1-312. Ode Gos.uNio. 276. 2T 630 DR. J. A, THOMSON ON THE [ Dec. 1913, is given to those which betray their origin most clearly. Many of the rocks are best described as being cf a nondescript character. The comparisons made with similar rocks occurring elsewhere in Western Australia are based mainly on the study of specimens kindly presented by Mr. Gibb Maitland, many of which were also analysed by the officers of the Survey. They show very clearly the general similarity of the massive amphibolites of the different gold- fields, and lead to the hope that each field will prove capable of resolution into its original constituent rocks after careful petro- logical study. The term greenstone is used throughout for rocks in which chlorite and carbonates predominate to the exclusion of hornblende and epidote or zoisite—tbat is, it is used in contradistinction to the term amphibolite and in the sense of the German griinstein. This is, no doubt, a restriction of the general usage; but it has this justification, that it obviates the necessity for a new term, and meets a definite need, It is only in rare cases that it is not possible to decide at once, on an inspection of the hand-specimen, whether a given rock is an amphibolite or a greenstone, and hence the wider use of the latter term is unnecessary. The Kalgoorlie greenstones are not mere surface-modifications of the amphibolites, but retain their characteristics to the greatest depth to which mining has been carried: that is, over 2500 feet. The distinction between amphibolites and greenstones (as here restricted) is of the utmost economic import in Western Australia. (a) The Sediments. There is some difficulty in obtaining specimens of the sediments suitable for microscopic study. - In the first place, the rocks them- selves, with the exception of the conglomerate-bands, are seldom exposed at the surface. As they have not proved auriferous, but little exploratory work has been done on them, and there is an absence of dumps from which fresh material may be obtained. Moreover, in the immediate neighbourhood of Kalgoorlie, cherty, slaty, and graphitic rocks of undoubtedly igneous origin are so abundant, that one hesitates to accept any rocks of similar appear- ance as sedimentary. ‘The processes of alteration have so far obscured the peculiarities of the igneous rocks that no microscopic criteria exist for distinguishing the two groups. Where undoubted sedimentary rocks crop out, as in the ridges south-east of Kurrawang, they are of much coarser texture than the slaty varieties above mentioned, and vary in character from grits to coarse conglomerates. At the surface, they are generally reddish or purple from the presence of oxide of iron. Sections show that the grits consist chiefly of quartz and felspar- in subangular or elliptical grains, with their longer axes parallel. The felspars belong both to orthoclase and. to acid plagioclase, and along with quartz often show strain-shadows. ‘There are, in addition, similarly-shaped areas of cataclastic quartz and felspar.. é Vol. 69.] PETROLOGY OF THE KALGOORLIE GOLDFIELD. 631 Next in abundance is biotite, partly in stout flakes irregularly dis- tributed, partly in thin plates with a well-marked parallel structure. It appears to be of authigenous character. A fair amount of chlorite seems to result from the alteration of the biotite. A little epidote, carbonates, and iron-ore complete the list of minerals. The rocks have evidently been subjected to a considerable amount of shearing. The matrix of the conglomerates is of similar composition, and is distinctly schistose. The enclosed pebbles consist chiefly of heematite-jaspers, liver-coloured quartzites, and quartz- and albite- porphyries. The last-named are indistinguishable from the albite- porphyries found at Kalgoorlie. A conglomerate of somewhat similar character, traced by Dr. Maclaren in a ridge 197 miles north-north-east of Kanowna, on the Kurnalpi Road, differs from the Kurrawang Conglomerates in containing pebbles of amphibolites, mostly of basic character. (5) The Fine-Grained Amphibolites. These rocks are found in various dumps, chiefly in the ‘ North End’ and on the western side of the main dyke of quartz-dolerite, but also less commonly on its eastern side. The known occurrences are too isolated for us to judge by these alone of the geological form. The rocks pass gradually into fine-grained greenstones, which have a wider distribution, occupying most of the Kalgoorlie ridge outside the main quartz-dolerite dyke. Unlike the coarser amphibolites described below, the fine- grained amphibolites retain no recognizable relict-structures. Their geological history cannot, therefore, be ascertained by microscopic study in the Kalgoorlie field. Muineralogically, they have the composition of amphibolites derived from basalts or more basic rocks. If they were of very limited distribution and confined to the immediate neighbourhood of the coarser intrusive rocks, it would be possible to consider them as the result of alteration of the chilled margins of these intrusives; but, along with the fine- grained greenstones derived from them, they occupy an area con- siderably broader than the widest dyke known in the field, so that this explanation becomes impossible, although perhaps some of the rocks here described are such chilled margins. Similar fine- grained amphibolites and greenstones, however, attain a consider- able development in other districts where coarse intrusives are unknown: as, for example, the ‘Six Mile,’ Kanowna. Since they apparently result from the alteration of basic igneous rocks, the most probable explanation of their origin is that they represent an older series of lavas and tuffs into which the coarser amphibolites are intrusive. A distinction may thus be made between the older and the younger amphibolites and greenstones. Mineralogically, the amphibolites consist chiefly of hornblende and zoisite, with smaller amounts of felspar, sphene, chlorite, carbonates, and quartz. ‘The hornblende is a pale variety, except 27 632 DR. J. A. THOMSON ON THE [Dec. 1913, where the rocks are contact-altered, and is generally disposed in small tufts with very irregular boundaries to the individual crystals. The spaces between the tufts are filled with very fine ageregates of zoisite, sphene, and quartz, and these minerals also occur in nests and venules along with chlorite and carbonates. Felspar occurs generally in platy crystals giving long lath-like sections, in which no extinction-angles greater than 10° have been observed for symmetrically-disposed albite-twins. In many of the rocks felspars appear to be absent, but have possibly escaped detection in the fine aggregates of quartz and zoisite. Fine-grained amphibolites showing contact-metamorphism are found in some dumps near Monument Hill, 3 miles south of Boulder Post-Office; and, as these dumps are surrounded on all sides by dumps containing porphyrite, it is probably to the agency of the latter rock that the contact-alteration must be ascribed. The hornblende is no longer pale, but is vivid green with bluish tones, similar to those displayed. by the actinolite-veins which ramify through the Cornish spilites in the contact-aureole of the Land’s-End granite. Both the hornblende and the clino- zoisite are reconstructed into larger and more euhedral crystals, and the sphene occurs no longer in granules but in wedge-shaped prisms. Biotite has developed to some extent within the horn- blende, while the clinozoisite contains kernels of orthite. Finally, the rocks are penetrated by venules of quartz, clinozoisite, and actinolite. All the above-described features are characteristic of contact-alteration in amphibolites. An additional feature in some of the specimens is the presence of small ellipsoidal white patches, measuring 23 cms. in their greatest diameter, which give a con- cretionary aspect to the rock. These consist of hornblende and zoisite, like the rest of the rock; but the hornblende is in less amount and in stouter prisms, while Zzoisite preponderates as a dense mosaic. Fine-grained amphibolites, in many respects similar to those of Kalgoorlie, have a fairly-wide distribution in Western Australia. Among the rocks which I described in 1909 from the West Pilbara Goldfield,t there are three that may be classed here (G.S.M. 6405 & 6415, Weerianna; 6429, 2 miles north-east of Mount Marie, near Roebourne). Because of the lack of relict- structures and the greater metamorphism which they showed in comparison with the coarser amphibolites, it was then suggested that they formed an older series, comparable with the Lewisian of Scotland. A re-examination of these rocks in the light of the experienced gained at Kalgoorlie shows that the greater structural metamorphism is due to contact-alteration, and that they were probably before then fine-grained amphibolites similar to those of Kalgoorlie. A better analogy of their probable relation to the coarse-grained amphibolites is illustrated by that of the Old Lizard Head Series to the Lizard serpentines and gabbros. In the Cue and Day-Dawn Goldfields, Mr. H. P. Woodward & 1 Bull. Geol. Surv. W. Austral. No. 33 (1909) pp. 182, 187, 141, & 143; also fig. 50, p. 141. s Vol. 69. ] PETROLOGY OF THE KALGOORLIE GOLDFIELD. 633 Mr. E. 8. Simpson have described a series of andesites capping one of the hills. They are stated to be vesicular, amygdaloidal, sometimes showing flow-structure and sometimes brecciated.* Some confusion of very different rocks has evidently taken place ; G.S.M. 6973, Créme d@’Or G.M.L. 389, is a very fresh igneous rock : from the published analysis it would seem to be a basalt rather than an andesite, and in all probability it is a comparatively recent dyke- rock; the other specimens which I have seen (G.S.M. 74 & 7307, Cue Hill; 3823, New Princess Extended G.M., Cue) are fine-grained zoisite-amphibolites, considerably contact-altered, and sometimes brecciated and recemented by a coarse matrix of hornblende and zoisite. An analysis of one of them is quoted below. Other localities where the fine-grained amphibolites have been recognized may be briefly cited :—Cumberland G.M., Norseman ; Laverton (G.S.M. 6537); Lennonville (G.S.M. 3966); Mount Malcolm (G.S.M. 4425); and Kimberley (G.S.M. 3749). No analyses from Kalgoorlie are available, but there are two of similar rocks from other goldfields, which agree closely enough with the analysis of the Ovifak basalt. { y a I JUG Ill SiO, 48°10 48°06 | 48°04 | DECC s Vin ae i a 0:41 0:90 0°39 Als03 15°41 16°21 | 13°13 Fe,03 10°32 0:89 | 6:89 REOM ee MIR Hed s. 4:33 10:37 1114 MnO 0°05 0°59 O11 MeO 6°38 6°67 | 517 | Cad 12°73 11:37 10°87 Na,O 211 2°50 | 2°83 KO 014. 0:27 0°06 H.O+ 0:33 0:59 — H,0— 0-04 0:10 | = P30; ae tr. 0°07 COS ai oes hats 0712 | 1:03 pas | Fess 0°25 0°34 — | See = — | 0:98 | een : = 0-79 H(?) nals = | 0:25 Clie = = | tr. Totals...... 100°72 99°89 100°72 Sits (2 aN aE 311 | 3:04 2958 Analyst..................) C. C. Williams. | E.S. Simpson. J. Fine-grained amphibolite. G.S.M. 3823, Cue. Bull. Geol. Surv. W. Austral. No. 29 (1907) pt. 2, p. 53. II. Vine-grained amphibolite. G.S.M. 4425. Mount Malcolm, Mount Margaret Goldfield. Ibid. No. 11 (1903) p. 7. III. Basalt. Ovifak, Disko (Greenland). H. Rosenbusch, ‘Elemente der Gesteinslehre’ 3rd ed. (1910) p. 399. Bull. Geol. Surv. W. Austral. No. 29 (1907) pt. 1, pp. 17-18; pt. 2, pp. 9, 44, 46, 52, & 53. 634 DR. J. A. THOMSON ON THE [ Dec. 1913, (c) The Fine-Grained Greenstones. Generally speaking, these rocks are most abundant in the southern part of the‘ North End,’ passing gradually into the amphi- bolites on the north and into the calc- schists on the south, without being positively confined to this area. They are dark-green massive or slightly-schistose rocks when mined, but frequently develop a latent schistosity after exposure for some years in dumps. Microscopically they are exceedingly variable in appearance, but agree in consisting of fine-grained aggregates of carbonates, chlorite, sericite, quartz, and rutile, to which should probably be added untwinned felspars, although these have escaped identi- fication. ‘There is seldom any well-defined structure, except in some cases a tendency to parallel arrangement in the sericite and chlorite, or the development of large rhombohedra of carbonates. All eradations from the Anewmined amphibolites to perfectly structureless greenstones can be traced, and it may be observed that hornblende disappears before zoisite or epidote. In the eastern part of the ‘North End’ are several occur- rences of an apparently concretionary greenstone with small light-coloured ellipsoids distributed in a dark-green dense matrix. These whiter patches differ from the rest of the rock only in the greater abundance of calcite, with a corresponding diminution in the amount of chlorite. In all probability, these rocks are derived from contact-altered amphibolites similar to those of Monument Hill described above; and it is found, on careful mapping, that they are distributed around the margin of the great intrusion of peridotite that lies within the greenstones of the ‘ North End.’ Another type of greenstone showing abnormal characters may be described here, although its position among the older greenstones is not unequivocal. On the east side of Trafalgar Township, east of ‘The Mile,’ are several dumps containing a schistose rock in which small, black, lustrous crystals of chloritoid are plentifully developed along planes oblique to the schistosity. This mineral has sharper outlines and higher refringence than the chlorite also present in the rocks, possesses a well-marked pleochroism in blue-green to yellow-green tones, shows polysynthetic twinning with oblique extinctions up to 28° measured from the trace of the twin-plane, and has a high birefringence and strong dispersion. A blowpipe examination failed to give a reaction characteristic of manganese, so that ottrelite is excluded. The rocks consist chiefly of calcite, forming broad bands of coarse mosaic alternating with narrower bands of chlorite (pennine), and it is within or near the last-named that the chloritoid is developed. Rutile is very abundant in slender prismatic crystals showing knee-shaped and heart-shaped twins, and is freely enclosed by the chloritoid. A small amount of quartz and muscovite sometimes accompanies the calcite. The rocks are often brecciated and recemented by a matrix in which chloritoid and pyrite play a considerable part. Chloritoid is usually regarded as a mineral characteristic of contact- y Vol. 69.] PETROLOGY OF THE KALGOORLIE GOLDFIELD. 635 or pressure-metamorphism, but Prof. EK. Weinschenk has remarked that it is absent in contact-rocks containing calcite. The presence of considerable amounts of chlorite and rutile shows that these rocks are not altered sediments, and suggests that they are formed trom the greenstones; but their field-relationships are not sufticiently clear to give the clue to their probable mode of origin. (d) The ‘ Cale-Schists.’ The name of ‘cale-schists’ was applied to these rocks by Dr. Maclaren before their true nature was ascertained, and has been adopted by Mr. Gibson. These rocks are more often massive than schistose, especially when freshly mined, and hence the name is not quite applicable; but it will be retained for convenience, since a distinctive name is necessary for the miner. The greatest development of the ‘calc-schists’ is on the eastern side of the quartz-dolerite boss of ‘The Mile’; but they persist for some distance northwards, gradually merging into the fine-grained greenstones. In hand-specimens they are whitish-green aphanitic rocks, intersected by dark venules like those of chalcedony in’ serpentine; and, owing to close jointing, they possess a very short fracture. They are so dense that a high power of the microscope is required to distinguish the individual grains of the carbonate of which the rock is mainly composed, and to reveal the presence of quartz between them. In places, they contain small lath-shaped sericitic areas recalling those of the felspars in the fine-grained amphibolites. Chlorite is absent, or but sparingly present in large flakes. Occasionally, large octahedra of magnetite are scattered through the rock. In the more schistose varieties the muscovite exhibits some approach to parallelism, and large rhombohedra of carbonate are frequently developed. (e) The Peridotites and their Derivatives. In the hills forming the western shores of Hannan’s Lake and the eastern slopes of Mount Hunt, 6 miles south of Boulder, a considerable area is occupied by a dense serpentine and a coarse carbonated serpentine. The former rock consists mainly of serpentine pseudomorphs after olivine-grains, embraced by a turbid mineral resembling bastite, and in addition a variable amount of tremolite, both as fine needles within the serpentine and as coarser prisms lying in the bastite. The original rock was probably, therefore, an augite or enstatite-peridotite. In the carbonated forms, the tremolite and bastite are little affected, but the ser- pentinous areas are almost completely replaced by a carbonate approximating to magnesite in composition. Within the Kalgoorlie area proper, serpentine has been observed in only two places: Mr. Simpson” has recorded a rock ‘of a serpen- tinous nature’ from the former Black Cat lease, G.M.L. 3862 E; 1 * Grundziige der Gesieinskunde’ vol. i (1906) p. 189. 2 «Ann, Rep. Geol. Sury. W. Austral. for 1900 (1901) p. 9. 636 DR. J. A. THOMSON ON THE [Dec. 1913, and a boring core from the neighbouring old Kaipai Mine, G.M.L. 3625 E, has also proved to be a serpentine essentially similar to that from Hannan’s Lake, except that it contains more original chromite and secondary magnetite. Though no outcrop of this serpentine can be found, the rocks in this neighbourhood (the eastern part of the ‘North End’) are largely derivatives of peridotites, and may be classed as tale-magnesite rocks and schists, magnesite-rocks, and fuchsite-magnesite rocks. In most of them all trace of the original structure has been destroyed, but the mineralogical composition leaves no doubt as to their original ultrabasic and highly magnesian character. The talcose rocks consist mostly of a schistose matrix of tale with subordinate biotite, chlorite, and quartz, in which matrix large euhedral rhombohedra of magnesite are enclosed. In hand-specimens these rocks are unusually dark for tale-schists, and can be distinguished from the greenstone schists only by their soapy feel. The magnesite-rocks differ mineralogically from the carbonated serpentines of Hannan’s Lake in the constant presence of tale and quartz, and structurally by the disappearance of recognizable pseudomorphs of olivine and pyroxene. The fuchsite-magnesite rocks are bright-green variants of the magnesite- rocks on the sides of small quartz or carbonate veins containing tourmaline, and consist of structureless aggregates of magnesite, quartz, fuchsite, and rutile. Similar derivatives of peridotites attain a great development in the country east of Kalgoorlie, and particularly in the Bulong, Waterfall, and Kanowna goldfields. A belt of serpentine very similar to that of Hannan’s Lake crosses the Bulong Road 62 miles east of Kalgoorlie, and shows clearly the peecilitic structure of the tremolite-bastite element, as also the invasion of the serpentine by delicate needles of tremolite. A distinct feature is the growth of secondary magnetite within the bastite, in long arborescent crystals. In the dump of the Oversight Mine, Bulong, is a beautifully lustre- mottled rock, obviously derived from a serpentine. In natural light, thin sections of this rock resemble an ordinary serpentine, because of the retention of strings of iron-ores along the edges and cracks of the original olivine. A small amount of serpentine is-occa- sionally retained in the centres of these original grains, but the exteriors are generally altered to tale. In parts of the rocks big crystals of carbonate replace the areas originally occupied by several olivine-grains, except for small patches of serpentine or tale in their centres which display in hand-specimens the dull patches of the lustre-mottling. 'lalc-carbonate rocks showing greater similarity to those of Kalgoorlie are found in the Golden Ridge Mine, Water- fall. At Kanowna is a hill of tremolite-serpentine north-west of the town, while fuchsite-magnesite rocks are very abundant near the gold-veins. Outside the Kalgoorlie fields, serpentines have not been very frequently noticed in Western Australia; but this does not necessarily mean that they are uncommon. Little exploratory work has been carried out beyond the immediate neighbourhood of known gold-occurrences, and serpentine is not a rock in which auriferous y Vol. 69.] PETROLOGY OF THE KALGOORLIE GOLDFIELD. 637 veins commonly occur, for the vein-solutions alter it to a talcose or carbonate-rock, and the tale-schists are frequently confused with the greenstones. ‘T'wo serpentines from the West Pilbara Goldfield, which I described in 1909,* differ from those of the Kalgoorlie type in the absence of bastite and tremolite and in the presence of flakes of biotite or chlorite derived from it; and another Pilbara example (G.S.M. 5375, hills near Box Soak), previously noticed by Mr. E. 8. Simpson,” is essentially similar. The serpentines described by the last-named writer and Mr. L. Giauert® from Ravensthorpe (G.S.M. 8154, 8326) appear to be dunite-serpentines showing incipient alteration to tale and carbonates. Talc-carbonate schists seem to be well developed at Warrawoona, while contact- altered tremolite-tale schists are found in fields of the Coolgardie type. ANALYSES OF DERIVATIVES OF PERIDOTITE. TVs] Vis Wale jee A VETATIS Ute OVE TSTATT: SHO ab AMA Aa ee iis 8) 31:07 33°80 | 3891 | 3063 SET OS ite ntay ine ah 0°60 0°26 0°33 | 0°06 0°52 Zr 05 oss — OO etn We Al,O3 656 5:49 Bok aj ey OSs Wed 68 (CrsORr eek. — = 0°50 — | _— ( trace W203 wc steeef oe aca ttt PN eae Fe.03 ee 1:49 0°40 1030 | 5°94 FeO. 9°45 7-64 8°70 180 | 472 MnO 1:57 018 019 0°08 O11 MgO 28°51 17:49 19°95 36°65 | 32°30 CaO 3°10 5-46 1°34 tr. | tr. BaO — — none — | — | NasO 0°73 3°82 0°30 0°40 | O41 | KO... 0715 O11 2711 bis ao Olel | TAS OyaeN ey he a! ae 9°05 0°05 0°59 10°89 0°52 13 US Oe aie Cee 0°14, 0:07 0:09 0°28 015 (OO ae sane none 27°24, 25°98 none 23:03 BES opie eae cea: none | 0:06 0-24 none | 0°20 | Totals ...... 99°21 | 100°43 100°37 | 100°45 100°32 VSD eaRes, (ES ae a 2°81 | 2°89 2°97 2°69 2°91 ACT ct €. C. C. G. Be Saa yeas. E.S. Gi eS Williams. Gibson. | Simpson. | Simpson. | Simpson. IV. Tremolite-serpentine. G.S.M. 3218. Near Hannan’s Lake, Kalgoorlie. Bull. Geol. Surv. W. Austral. No. 6 (1902) p. 75. V. Carbonated serpentine. G.S.M. 375. Island, western side of Hannan’s Lake, Kalgoorlie. Ibid. VI. Fuchsite-magnesite rock. Dump a quarter of a mile east of Hannan’s North, G.S.M. 2139 BH, Kalgoorlie. (Analysis hitherto unpublished.) VII. Chlorite-serpentine. G.S.M. 5375. Hills near Box Soak, Pilbara Goldfield. Bull. Geol. Surv. W. Austral. No. 15 (1904) p. 12. VIII. Tale-carbonate schist. G.S.M. 5757. Near Moolyella Gap, Warrawoona, Pilbara Goldfield. Ibid. No. 20 (1905) p. 66. 1 Bull. Geol. Surv. W. Austral. No. 83, pp. 144 & 147. 2 Ibid. No. 15 (1904) pp. 12 & 16. 3 Ibid. No. 35 (1909) p. 39. 638 DR. J. A, THOMSON ON THE [Dec. 1913, (f) The Hornblende-Rocks (Pyroxenite-Amphibolites). These rocks appear only in a few dumps, both on the east and on the west side of the main dyke of quartz-doierite, and are intimately associated with talc-schists and magnesite-rocks. The disposition of these dumps suggests that the rocks either form long, narrow, independent dykes in the peridotites, or that (with the latter) they form a banded complex. In hand-specimens and thin sections alike they are found to consist almost entirely of large interlocking crystals cf pale fibrous hornblende, without any trace of parallel structure, except in the immediate vicinity of local shear-planes. In places, the presence of brown hornblende of more massive character betokens a small amount of original hornblende. The brown hornblende shades off to green on its edges; generally it has outgrowths of massive tremolite, such as commonly occur on the original hornblende of uralitic and pilitic rocks. Iron-ores are rare, and are altered on the exterior into leucoxene or granular sphene. Still more rare are felspar (saussuritized), apatite, and biotite; while a small amount of interstitial micropegmatite has been observed in one specimen. As in all the amphibolites, surface-weathering has produced a variable amount of chlorite and epidote from the horn- blendes. The only rational explanation of the mode of origin of the dominant pale fibrous hornblende is that it is uralitic: therefore, the original rock must have been a pyroxenite containing a small amount of brown hornblende. Pyroxenite-amphibolites, with or without original brown horn- blende, have so far been found in only a few Western Australian goldfields, but are probably of wider distribution. G.S.M. 3963, from Lennonville, is, as Mr. Gibson’ has already pointed out, a partly uralitized pyroxenite, and consists only of augite, pale fibrous hornblende, and granular sphene. G.S.M. 8322 (trom Mount Desmond, Phillips River Goldfield), which Mr. Simpson & Mr. Glauert have compared with the Kalgoorlie type,° is a similar rock in which uralitization is complete. A more complete analogy with the Kalgoorlie type is shown by a rock from Lawlers (G.S.M. 7105), containing a small amount of brown hornblende in addition to the dominant uralite. A rock from Ravensthorpe (G.S.M. 8140), described by Mr. Simpson & Mr. Glauert* as an altered diabase, shows a much greater amount of brown hornblende, and in this respect constitutes a passage to the lustre-mottled amphibolites. The brown hornbiende is almost opaque from the presence of inclusions of iron-ores, arranged for the most part in rows oblique 1 Bull. Geol. Surv. W. Austral. No. 8 (1903) p. 13. 2 Ibid. No. 35 (1909) pp. 26, 28. 3 Thid. pp. 27, 43. y Vol. 69.) PETROLOGY OF THE KALGOORLIE GOLDFIBLD. 639 to the vertical axis of the erystals (fig. 1). It is often crystallo- graphically continuous with clear green or colourless hornbiende ; but the boundary-line is sharp, with no shading of colours as in the Kalgoorlie type. The bulk of the rock consists of clear, strongly- pleochroic, green hornblende in large and small crystals of more Fig. 1.—Hornblende-fels, G.S.M. 8140, Ravensthorpe, consisting of ___ original brown hornblende (shaded, and with oblique rows of (=. tmon-ores), secondary green hornblende (clear), and sphene (dotted). x20. : eDeias compact character than is the case with the simply-uralitized amphibolites ; and it is evident that the rock has attained a higher degree of metamorphism, most probably through contact-alteration. No analyses of pyroxenite-amphibolites from Western Australia are available. (g) The Lustre-Mottled Amphibolites (Hornblende- Dolerite- Amphibolites). These rocks in Kalgoorlie do not form separate intrusions, but occur as local variations of the main band of quartz-dolerite- amphibolite at two or three points on its western side. They may easily be detected in hand-specimens by the lustre-mottling on the cleavage-surfaces of large hornblende-crystals, which range up to 15 mm. in their longest diameters. 640 DR. J. A. THOMSON ON THE [Dec. 1913, Owing to the large dimensions of the hornblende-crystals, only a few of these appear in a thin section of average size. They are made up of variously coloured amphiboles, ranging from a deep brown through a vivid blue-green to pale-green and almost colour- less varieties, the last two being in excess. The lustre-mottling is the outward expression of a peecilitic structure—due in part to the enclosure of narrow prismatic masses of saussurite within the hornblende, and in part to the presence of ellipsoids of tremolite, surrounded by the coloured hornblende, but in crystallegraphic continuity with it. The saussurite-pseudomorphs are nearly opaque, and consist predominantly of clinozoisite and epidote, with relatively little albite ; they still retain the crystal form of the original felspars very faithfully. Jron-ores are not abundant, and are altered to leucoxene or granular sphene. In chloritized specimens pyrite is also present. The brown hornblende must certainly be regarded as original. Like that of the rocks described in the last section, it 1s often rendered nearly opaque by rows of ferruginous inclusions obliquely transverse to the cleavage-planes. In 1908, when studying the hornblende-peridotite and lustre-mottled amphibolite of Glenda- lough, I ascribed this structure to the magmatic resorption of augite’; but subsequent study of many similar rocks which exhibit it from Cornwall, Scotland, New Zealand, and Western Australia, has led me to the view that it is the result of an accommodation to increasing pressure according to the volume law. As it is known to develop only in the magmatically-formed brown hornblende of igneous rocks, it forms a valuable means of verifying the original nature of the brown hornblende of amphibolites ; and, further, when the original hornblende shows this structure, the distinction of the secondary hornblende is rendered more certain. The deeply coloured blue-green borders of the brown hornblende recall those so common in hornblende-peridotites, in which rocks they are usually explained as a bleaching of the brown variety ; although, possibly, they arise by an interchange of material with the pilitic hornblende formed from the olivine. The bluish hornblende is not arfvedssonite, as supposed by Mr. Simpson.? It is to be dis- tinguished from the blue-green hornblende of contact-altered amphibolites by its inconstant character, for it varies in colour gradually and irregularly from place to place; whereasin the latter the colour remains constant in any one crystal, or is suddenly replaced along a crystallographic plane by a different colour. The pale and often fibrous hornblende occurring in the interstices of the larger crystals as outgrowths on the brown and green hornblende, or as patches within the latter, must be regarded as secondary, and of uralitic or (as suggested below) of partly pilitic origin. 1Q. J. G.S. vol. lxiv (1908) p. 481, figs. 2 & 7. * Bull. Geol. Surv. W. Austral. No. 6 (1902) p. 64. Bey) 5 \ id Vol. 69.] PBTROLOGY OF THE KALGOORLIE GOLDFIELD. 641 The original rock was, therefore, in all probability a peecilitic hornblende-dolerite or gabbro. This view is confirmed by the study of a rock found by Dr. Maclaren 10 miles south-east of Kanowna. It is a hornblende-dolerite of the Careg-Llefain type, showing partial uralitization, and, where most altered, reproduces the features of the Kalgoorlie type. . The following is an analysis of a lustre-mottled amphibolite from Kalgoorlie, the only example of this class from Western Australia that has been analysed. The high percentages of carbon-dioxide, combined water, and soluble bases show that the rock had suffered much surface-decomposition, accompanied by the production of chlorite and carbonates. IX. Bases soluble in aqua regia. TiO, als 0°06 AUROa ee ae OISS: 4°11 HesO ated ety baat 013 0713 He Oe aca slek 14°22 5°00 GAO PBR ee Altes fs 1°60 1:13 MON re serntle sien 11°42 3°15 CaO Pe eas seers 10°43 0°59 INS Oper tees oS 1:02 KGS Oeieree tina on tk 0°20 1B IO asa ae 0°22 ENS Ree ae Ren 0°26 Total...... 100°22 Spwerimeanaet sea. 3°00 Analyst ...:........ C. G. Gibson. G.S.M. 2117. Main Shaft, Great Boulder, No. 2, South. G.M.L, 1219 E. Bull. Geol. Surv. W. Austral. No. 6 (1902) p. 67 Lustre-mottled amphibolites have not been found abundantly so far in Western Australia ; but one was described by me, in 1909, as almost a hornblende rock after a basic hornblende-olivine-gabbro.' The former presence of olivine was inferred from the presence of colourless ellipsoids of tremolite within the large peecilitic crystals of brown hornblende, but this phenomenon could be equally well explained by the uralitization of enclosed augite. In the case of the Glendalough rocks previously mentioned, the olivine of the hornblende-peridotite is partly altered into chlorite and tremolite, and the last-named has grown inwards from the enclosing brown hornblende in parallel position upon it, while the chlorite has developed along cracks in the olivine. In the Glendalongh amphi- bolite, where the olivine has completely disappeared, the abundance ? Bull. Geol. Surv. W. Austral. No. 83 (1909) pp. 132 & 142. 642 DR. J. A. THOMSON ON THE [Dec. 1913, of colourless ellipsoids of tremolite within the brown hornblende corresponds rather to the former proportion of olivine in the rock than to that of augite; and this leads to the belief that such ellipsoids in lustre-mottled amphibolites may be, at least in part, the result of the replacement of olivine. Unless, however, there are remnants of olivine still retained in a rock, it is unsafe to postulate the former presence of the mineral, as microscopic criteria for distinguishing tremolite formed from pyroxene and from olivine respectively appear to be non-existent. A priori, three types at least of lustre-mottled amphibolites may be distinguished :— (1) Those formed from hornblende-peridotites; (2) those formed from hornblende-olivine-dolerites or gabbros; and (3) those formed from horn- blende-dolerites or gabbros without olivine. Of these types only the last-named has as yet been found in Western Australia. A fourth possible type might be formed from a pyroxenite containing much original hornblende, or an augite- hornblendite, if the augite occurred in peecilitic crystals. The pyroxenite-amphibolite from Ravensthorpe described above approx1- mates closely to this category, but the lustre-mottling is very local in character. : Lustre-mottling is ‘not confined to igneous rocks containing pecilitic hornblende, but is also found in some that contain pecilitic augite. Amphibolites derived from such rocks would scarcely be expected to retain this character so clearly as those derived from hornblendic rocks, for the process of uralitization does not develop compact crystals, such as would give rise to smooth cleavage-surfaces like those found in residual brown hornblende. (4) The Epidiorites. These rocks are uralitized, saussuritized, and leucoxenized gabbros or ophitic dolerites, and are of a type so common that detailed descriptions are unnecessary. They have a very small develop- ment in Kalgoorlie, where they occur only as a local facies of the quartz-dolerite amphibolite, but are more abundant in the ridges to the west of the town; while an incompletely-uralitized dyke is found 33 miles south of Bulong on the Mount Monger Road. No analysis of this type from Kalgoorlie has been made. Hpidiorites are of very common occurrence among the amphi- bolites of Western Australia, and their derivation from ‘ diabase’ has in some cases been recognized by Dr. Vogelsang, Mr. Simpson, and Mr. Gibson. In 1909 I described several in detail from the Northern Goldfields, including pegmatitic varieties (G.S.M. 6401, 6410, 6414, 6434, 6437, 6442). The following analyses (p. 648) refer to rocks of this class. 1 Bull. Geol. Surv. W. Austral. No, 33 (1909) pp. 135-386, 138, 140, 146, 147, & 150; also figs. 45 & 46. é Vol. 69. ] PETROLOGY OF THE KALGOORLIE GOLDFIELD. 643 - ANALYSES OF WESTERN AUSTRALIAN EPIDIORITES. | | ayo XM RM) KILL. XEVe). | eve XVI. Sid. ....... 4627 | 4644 | 46°55 48:09 | 49:94 | 50°98 | 50:98 TiOs ......| 0°49 0°42 112 0712 0°52 0-70 | 0°79 Als03 ....:. | 23°85 | 20°22 | 15:36 19:77. | 19-45 | 11°06 1709 | Fe.03...... 1:36 1-91 3:19 1°43 i By Vase 0:87 BeO wy 351 3:99 8°79 699 T2N 10:67 8°35 MnO ....., O32 022 | 0:45 0:29 063 | O65 |. 1°35 MgO ...... | 665 9:19 9:80 756 | 9:64 5°88 4:70 WHO yo. 14°89 | 15:18 | 10°56 TOR a bL os S098} S70 NazO ....., 1°52 1:05 1:50 2°17 0°90 O75) No AOS AO ie fe Topas: 0°10 0:33 0:07 0:07 Pale AG 10 BOF AP wally 0°06 1:31 2°05 0-73 1:73 1:08 | EO eG 0.18 0°29 017 0:06 028 | 0:05 Pe Os We 011 0°36 0:06 = = = = COWES: | 0:25 O24 tr. 0:12 — none’ | none | FeS: ......) 0°08 0:20 tr. O11 0°05 0°44, a 019 | Totals...;100°71 | 99°76 | 99°31 10024 /10043 |101:06 | 99:24 | { — oneeeess oe ee ee = = | — 1 ESpagr |) 2:90}. 303 3°04. 2-98 2°94 2°94, | 2°95 oral | So lebese GVenc BS On, «| Cues Auely st. J-H-B. | J-H.B. ‘Simpson, Williams. Fugues Gibson. | Wallis ums. 2 xX G.S.M. 6874. Homeward Bound G.M., Cue. Bull. Geol. Surv. W. Austral. No. 29 (1907) pt. 2, p. 53. XI. G.S.M. 6870. Polar Star G.M., Cue. Ibid. XII. G.S.M. 4417. Yarri, North Cooleardie Goldfield. Ibid. No. 11 (1903) p. 7 XIII. G.S.M. 3847. Water Reserve 7745, Cue. Ibid. No. 14 (1904) p. 15; and No. 29 (1907) pt. 2, p. 53. XIV. G.S.M. 5999. Sunbeam G.M.L. 157, Norseman. Ibid. No. 21 (1906) p. 119. XV. G.S.M. 3751. Camp F.B. 32, Charnley River, Kimberley. Analysis hitherto unpublished. XVI. G.S.M. 5088. Tower Hill G.M.L. 4387, Leonora. Op. cit. No. 13 (1904) p. 19. (2) Derivatives of Quartz-Dolerite. The rock here named quartz-dolerite was originally a coarse- grained intrusive rock, such as that of Carrock Fell, termed by Mr. Harker a ‘ quartz-gabbro’ and by Prof. Rosenbusch a ‘ quarzdiabas.’ The original presence of such a rock in Kalgoorlie is demonstrated most clearly by the study of epidiorites with micropegmatite, but might be directly inferred also from some of the greenstones in which the original structural relations are not entirely obliterated. From these clear types one is led on by gradations to rocks of a very nondescript character, the parentage of which would be doubtful if they were foundisolated. All the various kinds of derivatives, when taken together, are found to form a broad band traversing the entire field in a north-north-westerly and south-south-easterly direction, and swelling out into a roughly boss-shaped mass in ‘The Mile.’ The boundaries of this mass are determined by a complex system of faults, but the northern and southern bands have the appearance of a dyke im situ. From the eastern side of the boss other thinner dykes run for some distance north and south. It will be convenient, in description, to group the rocks under three main types. 644 DR. J. A. THOMSON ON THE (Dee, 1913, A. Epidiorites with Micropegmatite (Quartz- Dolerite-Amphibolites). The amphibolitic variety forms a fairly-persistent band of varying width on the west side of the main dyke, and in parts of the ‘North End’ extends right across the outcrop. The rocks are, in general, not so deeply oxidized as the chloritic varieties, and may be collected at the surface in many places, notably near the Warden’s House and in the eastern railway-cutting through the Hannan’s Proprietary Lease (4222 E). South of ‘The Mile’ there is also a good exposure in a quarry in the old Leviathan Boulder Lease (1072 E). In hand-specimens the rocks are mostly coarse-grained and of a greenish-grey colour. ‘The bright cleavage-surfaces of dark-green hornblende are conspicuous, and appear to be scattered about in a dull-white saussuritic material. In general, it is impossible to recognize the presence of quartz without the help of a lens, nor is leucoxene so conspicuous as in the greenstones. The rocks at the southern end of the field have a darker green coloration, due to the prevalence of epidote, and are traversed by venules of quartz and epidote. Despite the alterations that have taken place, the structural relations between the minerals of the original rock are very com- pletely preserved. Saussuritic pseudomorphs of earlier columnar plagioclase are embraced ophitically by leucoxene and by uralitie pseudomorphs of pyroxene. In the interstices of the framework thus constituted a variable amount of micropegmatite or quartz occurs. The earlier felspars have rarely escaped complete saussuri- tization, and are generally replaced by almost opaque aggregates of zoisite, or more rarely of brownish-green epidote. The previously- existing pyroxenes are completely altered in the Kalgoorlie area to an almost colourless, markedly-fibrous uralite, which projects in a ragged fringe into the quartz-felspar intergrowths. Apparently, also, original hornblende was present: for there is a small amount of bright-green, pleochroic, compact hornblende on the outer borders of the uralite, and in crystallographic continuity with it. The marked contrast between the two varieties of amphibole must arise from some difference in mode of origin, and the simplest explanation is that the one is original and the other secondary. The iron-ores are occasionally preserved without alteration, but more often are represented by leucoxene and occasionally by granular sphene. The interstitial quartz and felspar often form micrographic intergrowths, but these are seldom so well-defined as those seen in the greenstones. The later felspar is obscured by inclusions of zoisite and sericite, but in places is fresh enough to allow the species to be recognized as an intermediate plagioclase. Both the micropegmatite and the interstitial quartz are rich in inclusions of apatite. The analysis of a Kalgoorlie rock of this type (tabulated on p. 645) is very similar to those of fresh quartz-dolerites from Great Britain. v Vol. 69.] PETROLOGY OF THE KALGOORLIE GOLDFIELD. 645 The presence of micropegmatite in the amphibolites of Western Australia was first pointed out by Dr. Vogelsang!in a rock from the Murchison district in 1897, but the inference that the rock was a derivative of a quartz-dolerite or a quartz-gabbro was not definitely drawn. Similar rocks are of very common occurrence in the Western Australian goldfields, but have generally been classed by the Survey officers as quartz-diorites, despite their basic nature. In 1909 I described several in detail as uralitized and saussuritized quartz-dolerites and quartz-hornblende-dolerites * (G.S.M. 6407, 6432, 6443, 6483, & 6484). ANALYSES OF QUARTZ-DOLERITES AND QuARTZ-DOLERITE-AMPHIBOLITES FROM WESTERN AUSTRALIA. XVII. XVIII. XIX. OM XXI. SSIKO5)) eeeubanes | 48°86 49°42 52°70 §2°31 51°93 | Op erie -| 0°22 1:95 0°83 Oral sleeve AlsOx........5 14°91 14°95 14:27 14-64 14°26 | FesO3......... — | 11°88 1:48 3°09 249 | HeOweey ee: 11°13 10°76 11:07 5°87 10°76 | Min @) a0: 0°90 O47 0:18 0°29 0°5 | MeO 765 616 639 8:90 5°28 CaO Cena. 12°19 9°85 8°23 9°32 7°89 NagO......... 2°58 2°70 3°15 2°67 2°79 Ke On eee oat 0719 0°72 0°23 0°59 0°81 lale(O es) eheeae | 151 077 0712 0°88 iets) JE O RS eae cene 0-04 0°09 O24 0°25 0°09 PSO s pasecian ss a 0°55 = O31 O31 COS Wane amas none none 015 0°05 none FeS2 ......... = 0°26 0-49 0°02 0°15 Totals......) 100°18 100703 99°53 99°50 100°21 Screen: 3°08 3°01. * 2°96 3°00 3°00 eee { C.C€. E.S. (?) C. G. E.S. EK. 8. Dh Sea Williams. Simpson. Gibson. Simpson. Simpson. XVII. Quartz-dolerite-amphibolite. G.S.M. 3231, Star of Colac G.M.L. 2872 E., Kalgoorlie. Bull. Geol. Surv. W. Austral. No. 6 (1902) p. 67. XVIIP. Fresh quartz-dolerite. G.S.M. 7728, Irregully Creek, Ashburton Goldfield. Thid. No. 33 (1909) p. 164. XIX. Quartz-dolerite-amphibolite. G.S.M. 5631, G.M.L. 375, near Greenmount G.M., Southern Cross. Ibid. No. 17 (1904) p. 20. XX. Quartz-dolerite-amphibolite. G.S.M. 6858, Red, White, & Blue G.M.L. 745, Cue. Ibid. No. 29, pt. 2 (1907) p. 53. XXI. Fresh quartz-dolerite. G.S.M. 7616, Secret Creek, Ashburton River. bid. No. 33 (1909) p. 164. Pegmatitic Varieties of Quartz-Dolerite- Amphibolites. These rocks are found in Kalgoorlie at various s places along ane smain band of quartz-dolerite- aiphibolite particularly on the “west 1 In K. Schmeisser, ‘ Die Goldfelder Australasiens’ Berlin, 1897, p. 44. English translation by H. Louis, London, 1898, p. 63. Bull. Geol, Surv. W. Austral. No. 33 (1909) PP. 186-87, 144-45, 150-51, & 155-56 ; also figs. 52 & 54. mene) Je G. Sar None 716: 20 646 DR. J. A. THOMSON ON THE [Dec. 1913, side of Mount Gledden (Maritana Hill) and in the dump of the Queen-of-the-West Mine, G.M.L. 942 EK. Although no natural sections have been observed im situ, large blocks in the dumps show that the pegmatitic rocks occur as narrow bands in the normal amphibolite. The rock from which they have arisen thus bears the same relation to the main intrusion, as the well-known gabbro- pegmatites of the Lizard district in Cornwall bear to the gabbros of that area. Hand-specimens show a very coarse mottled rock, of a prevailing dark-green hue, with white patches representing the felspar and quartz. The most noticeable peculiarities are the platy habit of the femic constituent, and the manner in which these plates are bent into curves with arcs approaching a semicircle, so that a broken surface of the rock seems to have small biscuit-barrels projecting from it. On atypical fragment, less curved than usual, one of these platy crystals measured 4 cms. in length, 1 cm. in breadth, and 2 mm. in thickness. A transverse striation is often to be observed in hand- specimens, although nothing corresponding to it has been detected in section. The quartz-and-felspar or saussuritic aggregates are generally of much smaller size ; but the iron-ores, which have also a platy habit, attain 5 cms. in their greatest diameters. Veins of yellowish epidote and quartz sometimes traverse the rocks. Microscopic study shows that the dark plates consist of a pale-green hornblende, and that the rocks are built on the same model as the normal quartz-dolerite-amphibolites, but on a much grander scale. The chief points of difference are that the pyroxene is represented largely by carbonates, chlorite, epidote, and magnetite, in addition to hornblende, and that the structure is not always clearly ophitic (for the platy felspars are sometimes moulded on the pseudomorphs of the pyroxenes). So far as | am aware, such pegmatites have not been described before, either in a fresh or in an altered state. B. The Quartz-Dolerite-Greenstones (Albitized Quartz-Dolerites). These rocks, along with those described in the next section, have a relatively-small development in the ‘ North End,’ but occupy the greater part of the quartz-dolerite intrusion in the ‘ Mile.’ ‘They are not mere surface-weathering forms of the amphibolites, but exist at depths of 2500 feet and over. Owing to the variety and extent of the alterations that they have undergone, they present little appearance of homogeneity, and the recognition of their original nature is not (at first sight) easy. The rocks here termed ‘ oreenstones * are more or less dark green from the abundance of chlorite; but every variation of colour is found between these and white or flesh-coloured rocks, in which chlorite is practically absent. The latter rocks are described in the next section as bleached greenstones, but it must be clearly understood that the boundary-line between the two divisions is an arbitrary one. In both groups there is every gradation between coarse granitoid varieties, approaching in texture the pegmatitic amphibolites above ; ’ Vol. 69.| | PETROLOGY OF THE KALGOORLIE GOLDFIELD. 647 described, and dense rocks hardly to be distinguished from the older fine-grained greenstones. Both groups, again, occur in perfectly massive and perfectly schistose forms; but the green chlorite-schists are quite subordinate in amount to the pale quartz-sericite-carbonate schists. A constant characteristic in all but the most schistose members is the presence of dull yellowish to purple patches of leucoxene, which are most clearly evident on wetted surfaces. Even where there is a considerable development of magnetite or pyrite, part, at least, of the leucoxene is commonly retained. In some of the massive greenstones the outlines of the felspars are visible in hand- specimens, and their prismatic forms have led more than one observer to describe them as phenocrysts." This deceptive appearance is due to the absence of distinct pseudomorphs of the original ferromagnesian minerals, which have altered to irregular masses of chlorite and carbonates and may easily be confused with the altered ground-mass of a porphyritic rock. Black blebs of quartz are abundant in the coarser roeks, the black being due merely to the background of chlorite in which the quartz is set. The most strongly chloritic rocks are found in the ‘ North End’ and on the western margin of ‘The Mile’: that is, in the proximity of the amphibolites. In section, the distinctive elements of the quartz-dolerites can clearly be recognized. The felspars are often well preserved as to form, although much coloured and obscured by chlorite along the cracks and cleavage-planes. They form large tabular crystals, often twinned on the albite law, less often on the pericline, and occasionally on rarer laws; but Carlsbad twins are seldom, if ever, seen. Their identification as albite rests on the following observations:—maximum extinctions on symmetrically- cut albite-twin lamelle of 16°, refringence lower than that of balsam, maximum birefringence always low, optical character positive. On the felspars are moulded highly-embayed crystals of ilmenite, more or less altered to leucoxene. At times, there is in addition a considerable amount of octahedral magnetite, which in some cases encloses the ilmenite or leucoxene. A former mineral, which embraced the felspars ophitically, is represented by aggregates consisting principally of chlorite, with smaller amounts of carbonates and in a tew cases of epidote. These aggregates are assumed to be the alteration-products of the original augite of quartz-dolerites, but there is no intrinsic evidence to prove that such is the case. The interstices between the above-described minerals (or mineral ageregates) are occupied by coarse or fine micropegmatite, the felspar of which is often polysynthetically twinned and may some- times be seen to’ be continuous with that of the large columnar erystals. Apatite occurs as inclusions in all the above minerals, but is most abundant by far in the micropegmatite as long slender needles. Tourmaline is a rare accessory. In rocks ‘such as those described above, where the original 1 As previously stated, Prof. Judd and Mr. Larcombe have termed these rocks ‘ quartz-andesites.’ Die) 74))| 0) 7) 648 DR. J. A. THOMSON ON THE [Dec. 1913, outlines of the felspars are retained, and the alteration-products of the presumed pyroxenes still form distinct pseudomorphs, the structural analogy with quartz-dolerites is complete. It follows that the alteration, as compared with the original rock, consists in albitization of the felspars, and in conversion of the ilmenite into leucoxene and of the pyroxene mainly into chlorite and carbonates. The question arises whether this alteration has been effected directly on the fresh quartz-dolerite, or after it had been first uralitized. ‘This will be discussed in the concluding part of this paper. The greenstones of ‘ The Mile’ seldom contain so much chlorite as the above-described rocks ; and, by a breaking-down of the sharp- ness of the pseudomorphs it is not always easy, and sometimes impossible, to distinguish the distinctive elements and structure of the quartz-dolerites. The felspars are seldom entirely destroyed, but have lost their rectilinear outlines, and what remains is much obscured by inclusions of chlorite, carbonates, and sericite. The felspars of the micropegmatite have often completely disappeared. Consequently, it is no longer *possible to isolate by exclusion certain aggregates of chlorite and carbonate as pseudomorphs of ophitic pyroxenes ; and the rocks are, to all appearance, structure- less aggregates of chlorite, carbonates, felspar, quartz, sericite, leucoxene, and apatite. Nevertheless, there are certain relict- structures of wonderful persistence, even under extreme alteration and after considerable shearing. Leucoxene is never completely absent, even in rocks in which much secondary magnetite or pyrite is present, and it preserves the large deeply-embayed forms which characterize ophitic ilmenite. Again, groups of quartz-grains extinguishing together, but widely separated by a structureless ‘aggregate of chlorite and carbonates, are found in the most altered rocks. Mr. Card,! who supposed that these represented fragments of still larger quartz-crystals undergoing replacement. aptly compared them to islets of an archipelago (fig. 2, p. 649). The common crystallographic orientation of each ‘archipelago,’ and the abundance of apatite in the ‘islets’ and the intervening ‘sea,’ combined with the presence of micropegmatite in the less altered rocks, seem conclusive evidence that the quartz once formed part of a micrographic intergrowth. Not only has replace- ment caused the felspars to disappear, but it appears also to have obliterated the finer particles of quartz, and to have encroached on the larger. While it may be admitted that such archipeligos of quartz might arise in the manner suggested by Mr. Card from the quartz of a granite, their conjunction with leucoxene leaves no possible parent but an intrusive basic rock containing quartz. As a secondary structure in these greenstones may be noted the occasional development of the carbonates into large euhedral rhombohedra—cutting indifferently across the junctions of the former minerals, and enclosing quartz, leucoxene, and muscovite. Often the composition of the carbonates varies from place to place 1 Rec. Geol. Sury. N.S. W. vol. vi, pt. 1 (1898) p. 23. Pay I 4 Vol. 69.] PETROLOGY OF THE KALGOORLIE GOLDFIELD, 649 in the same crystal, as if it were affected by the character of the minerals undergoing replacement. A similar development of large magnetite octahedra frequently accompanies the formation of the carbonate rhombs, but is also noticed in rocks in which the carbonates are not thus individualized. As both these minerals occur in sharp and uncrushed crystals in highly-sheared rocks, their formation appears to be posterior to the shearing. Schistosity in the greenstones is most pronounced in the vicinity of the Golden Gate railway-station (at the north-western corner of Fig. 2.—‘ Archipelago’ of quartz in quartz-dolerite-greenstone, Ivanhoe G.M. x 30. [The quartz is in the position of extinction. The rest of the field (not filled in) is occupied by a mixture of secondary minerals. | ‘The Mile’), where every gradation between a slightly-sheared greenstone and a highly-fissile chlorite- schist may be observed. In the intermediate types ‘ augen,’ formed of archipelagos of quartz and slightly-deformed leucoxene- crystals, are wrapped round by parallel layers of chlorite and muscovite, interspersed with bands of granular quartz. In the most schistose types the leucoxene is drawn out into long lenticular streaks, and has been largely replaced by rutile; the larger ‘ augen’ of quartz have broken down, and parallei layers of chlorite and subsidiary muscovite alternate with layers consisting of a fine-grained mosaic of quartz, felspars, and carbonates. There are many abnormal types of quartz-dolerite-greenstone, both in the ‘North End’ and in ‘The Mile’; but, as their 650 DR. J. A, THOMSON ON THE [Dec. 1913, significance is doubtful, and as they are geologically unimportant, it will serve no useful purpose to describe them in detail here. Mention should, however, be made of one specimen which might be considered the result of contact-metamorphism, as it occurs in the vicinity of a dyke of albite-porphyry. It was collected in the western cross-cut off the west drive, at the 300-foot level of the Hannan’s Star Consolidated G.M. The rock has a dull-grey coloration seldom seen in any other variant of the quartz-dolerites ; but, in section, it differs from the ordinary greenstones only in the substitution of chloritoid for chlorite in the pseudomorphs after the original pyroxene. Occasionally, the chloritoid projects into the sericitized felspars. Except in the occurrence of chloritoid, there are no churacteristics suggesting contact-alteration, and greenstones, from the contact of the aibite-porphyry at other localities do not contain chloritoid, ' Analyses of the greenstones will be found at the end of the next section (p. 652). C. Bleached Greenstones (Albitized Quartz-Dolerites without Chlorite). These rocks, as mentioned above (p. 646), pass gradually into the greenstones, and the distinction made is only for purposes of deseription. ‘They occur chiefly in ‘The Mile,’ and, without forming exclusively the walls of the telluride-lodes or the matrix of the ores themselves, they are most abundant in what may be termed the lode-channels.* Sometimes, particularly in the ‘ North End,’ the bleached greenstones are found as thin yariants of the greenstones on each side of venules of quartz or albite. At other times, especially in parts of ‘The Mile,’ they form wide bands of rock alternating with similar bands of greenstone, the boundary between the two being sharp and usually along a strong joint- plane. This mode of occurrence has been supposed to indicate a later intrusive origin for the rocks under discussion, particuiarly where they have been identified as granophyres. It is probably due to movements along the joint-planes faulting out of sight those spots where the gradation between the two rocks occurs. Such gradations can be observed in innumerable cases, if very close inspection be made. Mine-workings are nearly always smothered with dust or slime, the lighting underground is poor at the best, and, in consequence, much hammer-work and close inspection is necessary before the true relationship of two adjacent rocks can be made out. Sudden breaks are much more easily noticed than 1 The lodes of ‘The Mile’ may be divided, on geographical grounds, into three groups. ‘he western group contains the lodes of the Ivanhoe, Great Boulder, and Golden Horseshoe Mines; the central group includes those of the Kalgurli, South Kalgurli, Great Boulder, Perseverance, and Lake-View Consols Mines: and the eastern the lodes of the Oroya-Brownhill, Associated Northern, and Associated Mines. Within each group the lodes are close together, and run in a belt of sheared and mineralized country that may be termed a lode-channel. The three groups are separated by broader belts of barren greenstone. The lodes of the western and central groups are in the quartz-dolerites, those of the eastern group in the cale-schists. v Vol. 60.] PETROLOGY OF THE KALGOORLIE GOLDFIELD. 651 gradual passages. Here it may be observed that, although there is always an inherent probability of finding granophyres in association with quartz-dolerites, [ have failed absolutely to discover any trace of them in Kalgoorlie, every suspected rock proving on microscopic study to be a metasomatized quartz-dolerite. In hand-specimens the coarser rocks are white or various shades of pink, and present much outward similarity to granites; but they always reveal their doleritic origin by the presence of leucoxene. Microscopically they exhibit in many cases their original structure much better than the greenstones, for the absence or paucity of chlorite (an obscuring element in the greenstones) makes the distinction between the various pseudomorphs much sharper. The pyroxenes are represented by dense aggregates of carbonate grains disposed around the partly- or completely-sericitized felspars. Micrographic and micropegmatitic intergrowths of quartz and albite are often beautifully displayed, and in such abundance as to make it evident that the rocks thus altered were slightly more siliceous than those parts of the same intrusion that are now repre- sented by amphibolites. The felspars, wherever identifiable, are albite, as in the greenstones. The leucoxene is frequently replaced by rutile, a process that becomes more marked with advancing schistosity. As in the case of the greenstones, however, many of the rocks are not such obvious derivatives of quartz-dolerites, owing to a greater development of carbonates and sericite. They consist apparently of coarse-grained structureless aggregates of secondary minerals (chiefly quartz, carbonates, and sericite), but there are few in which the presence of leucoxene or of archipelagos of quartz does not betray the original character. Most of them contain a large amount of pyrite, the iron of which appears to have been furnished largely by the chlorite, for a disappearance of chlorite goes hand in hand with the appearance of pyrite.’ Secon- dary magnetite is fairly common, while hematite and arsenopyrite are occasionally found. In the immediate vicinity of the lodes these rocks are represented by pale-grey schists with silvery foliation-planes, often rough by reason of imperfect shearing or from the projection of octahedra of magnetite. In microscope-sections the schistosity is less evident than the hand-specimens would suggest. Sericite is the first mineral to assume a parallel development, and next to it comes chlorite (if any exists in the rock), then the carbonates, which are drawn out into lenticular streaks. The large magnetite-crystals seem to be posterior to the shearing: for their edges are quite sharp, and they are never flattened or drawn out. The ultimate products of the shearing are fine-grained schists with a granular quartz base, in which certain bands are very rich in rutile. These quartz- carbonate-sericite schists are the rocks regarding which Mr. L. J. Spencer* expressed doubts concerning their relationship with 1 The alumina of the chlorite is probably utilized in the formation of sericite, while the magnesia is removed or goes into the carbonate. 2 See p. 629. 652 DR. J. A, THOMSON ON THE [Dee. 1913, the amphibolites. Great as are the mineralogical and chemical differences, there can be no doubt that both are derivatives of quartz-dolerites. The following analyses (selected from a large series published by Mr. Simpson) illustrate the somewhat variable chemical com- position of the greenstones and the bleached greenstones. An analysis of an albitized quartz-dolerite from Scotland is appended for comparison :— ANALYSES OF QUARTZ-DOLERITE-GREENSTONES & BLEACHED GREENSTONES. | | | ZOU SORT TES IS SXEXTIV' al) SEXOVE: | SKONGV AIH eNGXGVATAIE SHOW Lebelonsesset, Sez 55°84. 45°55 A694 | 42:01 | 59:33 OS ee WB 4) Ora 063 | 014 O81 3°42 FNS Sipe | 9:68 10°38 10°88 | 1249 | 842 | 12°86 HesOs 1.85 | 6:49 4°39 4°14. 0°33 9A5 | Ae SS ane TNO) Mong senaccll ey ply 12°82 13°18 9:20 | 15°76 6:46 Mn@y ese pathy ; 0:09 0°38 tr. 0:32 | Ol 014 MeO es | 1°63 0°54 2°31. 3°56 1:67 209 CHOW MESES 5:05 4:18 752 643 | 707 | 3°74 NasOn eee 3:92 3°40 3:04. 1:84 | 92°62 513 GOH eee 0712 0:76 026 | 257 | 1:15 215 TSO) 151 1:83 1-74 | 030 0:67 219% HEO— eee 016 | 0:05 027 | 009 | 023 -| 048 P30; Seeabe vou cos| a = = | cast Src 0°388 COs eee IS 1:84, 4-99 1026 | 1341 | 15°65 = Bee hs | = — — = = 0:044 HeSar eae | = 0:22 034 | 225 | 0-30 0215 | Totals...... 98°51 100°33 100712 99.87 | 9922 10044 | Bases soluble in aqua regia :— INIBO® | Gashoneee 4°46 3°50 0:78 0°31 0:20 = ResOs eee | 6:49 4°39 414 | 0:33 2-45 = HEOwe ee 842 11-79 10°50 8°49 14:37 = HAO soossesocces| OWS) 0°33 tr. 0°32 0:41 = MeOve ee: 1°63 0:54 2-08 3°56 1:67 = CAO eed 3°34 3-98 7-28 6:33 574 = Sp. gr. Pay 3°04 290 2°91 2°94 3°00 {y feet SCAT NCHG: By 8.) | C. G. Can Sew nalyst -- | Williams.} Gibson. | Simpson. | Gibson. | Gibson. | Falconer. | jee * HoO+ and CO.=2'12. XXII. Epidotic greenstone. G.S.M. 1936, Hannan’s North G.M.L. 673 E. Main shaft, 600 feet. Bull. Geol. Surv. W. Austral. No. 6 (1902) p. 67, XXIII. Greenstone. G.S.M. 1800, western crosscut, 300 feet, Golden Horseshoe G.M.L. 993 EK. Ibid. XXIV. Greenstone. G.S.M. 1730, main shaft, Imperial Boulder, G.M.L. 1222 Ibid. |‘ Chlorite-schist.’| XXV. Bleached greenstone. G.S.M. 1753, 400-foot level, Ivanhoe G.M.L. 116, Boulder. Zéid. [‘Lode stuff: chlorite-schist.’ | XXVI. Bleached greenstone. G.S.M. 1751, western crosscut, 400 feet, Ivanhoe G.M.L.116. bid. [*‘ Massive siderite-rock.’ | XXVII. Light-coloured felspathic modification of quartz-diabase. Kettlestoun Quarry, Scotland. J. D. Falconer, Trans. Roy. Soc., Edin. vol. xly, pt. 1 (1906) p. 147. yee cert y Vol. 69. | PETROLOGY OF THE KALGOORLIE GOLDFIELD. 653 The practice adopted by the chemists of the Western Australian Geological Survey of giving, in addition to the complete analysis, a statement of the part of the rock that is soluble in aqua regia, is highly commendable in the case of rocks containing much chlorite and carbonates: for thus it is possible to make an approximate estimate of the quantitative mineralogical composition. In these calculations one method is to employ arbitrary molecules for chlorite and sericite ; and this has been adopted by Dr. W. Lindgren* for the calculation of two of the analyses of the foregoing table. An alternative method, adopted by me, assumes an arbitrary choice of disposal of the soluble bases between carbonates and chlorite, and attempts to calculate the various molecules postulated by Tschermak for chlorite and sericite according to the ratios between combined water and the available bases. ‘The latter method would be more exact if the analyses were absolutely reliable ; but, in the absence of estimates of fluorine and chlorine, the figures given for combined water cannot be accepted as quite accurate. Nevertheless, it is interesting to note the close agreement of the calculations, par- ticularly as it is evident from the slight divergences in the fixed molecules that slightly different atomic weights have been used. The estimates for the rocks in the foregoing table are as follows (XXV a and XXVIa being the estimates of Lindgren) :— ) { | | | | | LOMOR D:O:0 006 KORN LX Vie IX XV Le ROX ce: 3 LG SRC RM 2 SO a —— Leucoxene............ — 1°51 0°34, — 1:98 — | mentite eines) 2p4n — _— — = Magnetite .........) *7745 | 6:36 0-48 0-47 3°55 3°53 Pyrite Nee eel a 0:22 2°25 2°25 0°34, 0°30 MSO! SN AWE eae SB) 28°72 15°56 15°70 | 2216 | 22°12 Anorthite .........) — 0°97 | 0°50 — 0°44; — MOIsitee ee Len oh SAS = = == = — | Tron-epidote.........| 3°06 | — | — — — ae Seniciey eee sOaw | 645 | 21-73 21°52 9°71 958 | @hilorite 2 9 13°82 16°39 2°85 2°76 1-24 2°94. Carbonates ......... 418 11°94 31°35 31:48 | 38°27 | 38:24 Quartz 2.) §h)! 25:26).| 27-85 25°13 25°20 | 21:23 | 21:44 Totals.........) 9850 | 100-41 100°19 99°38 | 98°92 | 9815 No. XXIV could not be thus calculated, as the analysis shows much insoluble iron and alumina that cannot be accounted for. While it is frankly admitted that the results can only be accepted as approximate, the above table reveals several interesting points. The first is the thorough nature of the albitization, for little or no insoluble lime remains in any of the rocks, except the epidotic greenstones. The second is that, as the amount of sericite and carbonates increases, the proportions of albite and chlorite decrease. Apparently, after the production of the greenstones by albitizing solutions, in which process chlorite was freely formed, a further 1 ‘Metasomatic Processes in the Gold Deposits of Western Australia’ Econ. Geol. vol. i (1906) p. 538. S3 54 DR. J. A. THOMSON ON THE (Dee: 1938 alteration by later solutions took place, leading to more exten- sive formation of sericite and carbonates at the expense of the albite and chlorite. ‘The term ‘ bleached greenstone’ has been applied, not only because it avoids the necessity of some such phrase as ‘metasomatized quartz-dolerite without chlorite’; but also because I believe that the rocks thus named have actually passed through the greenstone stage, and have been dechloritized. The amount of free quartz is much greater than is to be expected in a fresh quartz-dolerite; but it may probably be explained by the liberation of secondary quartz during the alterations sketched out above, without any extensive addition of silica to the rocks. Lode-Matter in the Quartz-Dolerites. The term ‘lode’ or ‘lode-formation’ is used in Western Aus- tralia for a body of ore which is not clearly a quartz-vein or reef, and has the general appearance of a rock rather than of a fissure-filling. It is generally agreed that the ‘ lode-formations’ are zones of rock that have been strongly fissured or sheared, and impregnated or replaced in part by valuable minerals." The only criterion of whether a given piece of rock is ore or country is the economic one of whether it will be profitable to mine or not. Such. lodes are found in severai kinds of rocks in Kalgoorlie; but those in the quartz-dolerite are the richest, and alone carry persistent shoots of ore. Most of the bieached greenstones bear some percentage of pyrite, and are never without at least a low tenour in gold ; whereas the greenstones are predominantly barren. ‘The greater part of the actual ore mined consists of bleached greenstone-schists or much-silicified replacements of them; nevertheless, some of the high-grade telluride-ores are almost perfectly-massive green- stones or bleached greenstones such as have been described above. Detailed descriptions of the various kinds of ores would occupy too much space in a paper that is already of great length. (7) The Porphyrites. The rocks here classed together present considerable variety when compared one with the other, and range from grey rocks of dioritic facies to light-coloured, eminently porphyritic types, hardly distinguishable from the albite-porphyries. The porphyries and porphyrites differ from all the other rocks of the field in containing phenocrysts of felspar, and are thus easily recognized. The distinction drawn between them rests chiefly on the presence of hornblende and biotite in the porphyrites, and on the absence of these minerals in the porphyries. As a rule, too, the porphyrites consist more preponderatingly of phenocrysts, with a consequent diminution in the amount of the groundmass, and thus approach more nearly to plutonic rocks. 1 See H. P. Woodward, ‘The so-called “ Lode-Formations” of Hannan’s, & Telluride Deposits’ Mining Journ. vol. Ixvii (1897) pp. 1869-70. di Vol. 69.] PETROLOGY OF THE KALGOORLIE GOLDFIELD. 655 While the porphyries range as dykes through the quartz- dolerites, ‘ calc-schists,’ and peridotites of the Kalgoorlie ridge, the porphyrites are found chiefly in old dumps of abandoned mines and water-shafts in the valley west of ‘The Mile’ on which Boulder is built, and consequently it is not clear through what rocks they are intrusive. ‘The distribution of these dumps, and of some outcrops on the rising ground, favours the view that there is a broad band of porphyrite with a trend similar to that of the other intrusives; but, if so, it is a composite intrusion, for the nature of the rocks varies in nearly every dump. In the hills composed of epidiorites and quartz-dolerite-amphibolites west of the Kalgoorlie-Boulder valley, there are various small dykes of porphyrite ; and Dr. Maclaren has observed them as far to the south-east as Mount Monger. The differences within the group lie partly in the varying pro- portions of phenocrysts and groundmass, and partly in the relative proportions of felspar, hornblende, and biotite. The rocks which agree most closely with typical porphyrites show small phenocrysts of black hornblende and white felspar in a white or yellow felsitic groundmass. ‘The more micaceous varieties are grey to black, and devoid of apparent phenocrysts ; while the almost dioritic type from the Power-House Reserve presents a distinctly plutonic aspect, with only an occasional larger white felspar to bear witness to the porphyritic structure. In some localities, the rocks are curiously mottled by the presence of inclusions. ‘These are mostly of a white felsitic rock in a typical dark porphyrite, but to a limited extent consist of still darker, more hornblendic varieties. The white inclusions sometimes present great resemblance to the albite- porphyries, but differ in the presence of occasional phenocrysts of hornblende. It is, apparently, to these mottled rocks that Mr. Campbell and Mr. Simpson have applied the term ‘ orbicular,’ although the analogies with napoleonite are of the slightest. Another type of inclusion, occurring in the diorite-porphyrite of the Power-House Reserve, consists of coarsely-crystalline, black, ‘ basic segregations, made up chiefly of hornblende and epidote, with subordinate carbonates and magnetite. The rocks are never quite pach, the felspars always containing more or less sericite, and occasionally a little zoisite. Other secondary minerals of common occurrence are uralite, epidote, chlorite, albite, carbonates, rutile, magnetite, pyrite, and quartz. The phenocrysts consist of apatite, felspars, hornblende, biotite, and rarely quartz; while the groundmass apparently consisted chiefly of felspars with subsidiary quartz, hornblende, and biotite, but is now much obscured by secondary minerals. Apatite occurs sparingly in swall but stout hexagonal prisms, and is generally turbid from alteration. In one rock it exhibits schillerization and distinct pleochroism. Hornblende is found in somewhat elongate pale-brown or green prisms, showing sharp cross-sections with prism and B-pinacoid faces, or longitudinal sections with the dome (011), and frequently twinned on A (100). 656 DR. J. A. THOMSON ON THE [Dee. 1913, Pale uralite, preserving the octagonal cross-sections of pyroxene, has been observed in one rock; while actinolitic outgrowths on the hornblende-phenocrysts, and uralitic cores within them, in several other rocks, suggest that a small amount of pyroxene was originally present. Biotite is very abundant in those specimens which Fig. 3.—Albitized porphyrite, Pewer-House Reserve, showing an area of secondary albite, calcite, and epidote. x 4o. Ce YS nasi KN NOR Calcite Epidote Secondary albite [Hornblende and biotite, lying in the groundmass, have been omitted for convenience. | approximate to plutonic rocks in structure, but assumes diminish- ing importance with the greater abundance of groundmass. It occurs in anhedral platy crystals, generally associated with the hornblende-phenocrysts, or often partly or wholly enclosed within them. The felspars are always euhedral as phenocrysts, and yield quadrate or hexagonal outlines according to the direction of section. Albite-twinning is predominant, both simple and polysynthetic ; v Vol. 69.] | PETROLOGY OF THE KALGOORLIE GOLDFIELD. ps OB pericline-twinning is rare; while Carlsbad twins have not been seen. Zoning is occasionally observed, but the zones do not always show a regular progression of decreasing basicity from centre to margin, since there is frequently an alternation between the same two species of plagioclase; nor is there any great difference in composition between the zones, for the extinction-angles do not differ by more than a few degrees. The centres of the crystals are too highly sericitized for exact determination ; but there is generally a clear zone on the exterior, which agrees in refractive index, ex- tinction-angles, and optical character with albite. ‘The sericitized kernels are probably in some cases more basic, but in others they agree prefectly in optical characters with the clear border of albite. As undoubtedly secondary albite is present in some of the rocks, in nests associated with epidote and calcite (fig. 3, p. 656), it is pro- bable that the phenocrysts which now consist of albite are albitized lime-soda felspars. The felspars of the groundmass are similar both in habit and in composition to the phenocrysts, and are never microlitic. Quartz is of rare occurrence as a phenocryst, in rounded forms like those observed in quartz-porphyries. In the diorite-porphyrite of the Power-House Reserve it occurs in a micropegmatitic fringe to the felspars, and in addition as a mosaic of secondary grains in the groundmass. The view that the porphyrites are partly (and, in some cases, completely) albitized rocks is supported by the following analysis of a specimen (G.S.M. 2943) from a shaft in the Water Reserve No. 3393 E :— XXVIII. SiO. . 63°05 Miser vein: 0:97 AlsO3 ...... 1404 Fe,03 pecan Ta 1X0) Sabana 5°36 W5n(O) ,cpese cco 0:02 Sp. gr. 2°75. Analyst—C. C. Williams, in MgO ......... 158 EK. S. Simpson, Bull. Geol. Surv. W. Austral. No. 6 SEO 5:92 (1902) p. 74. Na,O bh one 6°74 GRU! eae dod ste 0°62 ASO CE sna: 0°26 H,O— ...... 0°04 COM =: 147 In the description of this rock given by Mr. Simpson, it is stated to be decomposed, from which we may infer that. the felspars are sericitized, while the presence of iron-ores and calcite is noted. The analysis should, therefore, contain iron sesquioxide. If the potash were present as orthoclase, the felspars would be, by calculation after the American method :— Per cent.: Orthoclase qi we rae a Suu 367. ACIDE pean yuna) Tanya 56°96 AN AOR AGNULED: Vers see eo nee GARE cr ae Rae Au 6:18 658 DR. J. A. THOMSON ON THE [Dec. 1913, But, as the potash is probably present in sericite, and controls more alumina in this mineral than in orthoclase, and as the hornblende is presumably aluminous, the amount of alumina ayail- able for anorthite is probably not so great as the above calculation assumes, in which case the preponderance of the albite molecule will be more marked. In view of the variations shown by the porphyrites, and their interest as a hitherto unknown member of the spilite suite, the preparation of a larger series of analyses may be recommended as a task well worthy of the attention of the officers of the Geological Survey. (k) The Albite-Porphyries. These rocks occur in distinct dykes running approximately north-north-west and south-south-east through the quartz-dolerites and peridotites : they also, in close association with graphitic schists, occupy a considerable area of low country between ‘The Mile’ and Hannan’s Lake, between the south-eastern and south-western dykes of quartz-dolerite. In hand-specimens they are white or pink: the white varieties being coarsely porphyritic and frequently deformed by shearing, while the pink varieties are less conspicuously porphyritic and with difficulty distinguished from some of the finer bleached quartz-dolerite greenstones. The distinction from the latter can usually be made, because of the almost universal occurrence of small apple-green inclusions in the pink porphyries. Under the microscope, the porphyritic structure is well expressed by the presence of large euhedral crystals of albite, essentially similar to those found in the porphyrites. There is, however, a gradual diminution in the size of the albite-crystals, so that it becomes difficult to determine where phenocrysts end and groundmass begins; but the smallest crystals of the latter are allotriomorphic. The ground-mass is much obscured by secondary sericite, carbonates, and quartz: there is no suggestion, however, of orthophyric or trachy tic structures. The only evidence of any other original mineral is furnished by well-defined, often hexagonal areas of chlorite, carbonates, and some- times fuchsite, surrounded by a rim of minute prisms of rutile. These are best developed in the strong dyke that runs from the Golden Gate Station through the Hainault, South Kalgurli, Per- severance, and Associated Mines, but are practically absent in the dyke associated with the graphitic schists in the Great Boulder Mine. They appear to be pseudomorphs of hornblende-phenocrysts; and, if this be the case, the resemblance between the porphyries and the porphyrites becomes still more marked. The above description applies to the freshest specimens studied ; frequently the rocks are extensively carbonated and sericitized, and the sheared specimens are practically quartz-sericite schists with augen of albite. Three analyses of these rocks haye been published by Mr. E. 8. Vol. 69.]. PETROLOGY oF THE KALGOORLIE GOLDFIELD. 659 Simpson,’ of which only one (the first) is sufficiently fresh to admit of comparison with similar rocks from elsewhere. The analysis (XXVIII) of the albitized porphyrite is repeated from p. 657 for the purpose of comparison. ORNS | OOe SOO SOAVAHUL, | SiO ais 68°12 65°51 62°16 63°05 EKO) | Sant ac eae 0°62 tr. 0716 0:97 — PE OR ee eto 2 | 15°97 18:12 14:98 | 14:04 Nee O by see ceanane eal 1:09 tr. 0°39 . — He Opes oe 227 2:39 - 3:03 536 IO R Eos TA al tr. 0:05 051 0-02 MgO 0-92 | 0:38 1:32 | 1°58 CaO O71 2°10 Tse te | 592 Na,O 6:03 4:27 618 | 6:74 KO | 1:29 | 3:28 1°59 | 0°62 H50+ | 0:29 0:46 0:25 0:26 H.0— 017 0:07 0:07 0:04: COs 1:13 2-41 565 1:47 FeSs tr 0°06 0°60: — Totals...... 98°61 99:10 100°92 100-07 Bases soluble in agua regia :— Al,03 0°31 0°46 0:58 — Fe,03 1:09 tr. 0:39 ae FeO 2°27 173 3°03 _ MnO oe tr. 0°06 051 — MSOs ens « 0°58 0°38 1-32 0 4 ra (CAO ee 2. 0°35 | 1:99 | 403 | — Spy Steerer ne ess. 2°60 2°72 272 | 2°75 Analyst ............|E.S. Simpson.| C. G. Gibson. | C. G. Gibson. | C. C. Williams. XXIX. Albite-porphyry. G.S.M. 1743, main shaft, Boulder Bonanza, G.M.L. 1064 E. XXX. Albite-porphyry. G.S.M. 1980, Hannan’s Hundred Acres, G.M.L. 1226 B, 150-foot level. XXXI. Albite-porphyry. G.S.M. 2219, 700-foot level, Brookman’s Boulder, G.M.L. 749. : The felspars may be calculated as before, with the following result :— X XIX. XXX. XXXII. XXVIII. Orthociase ............. 7°62 19°38 9°40 3°67 JOTI Bee odes sea cdosee 52°67 30°39 52°25 56°96 Anorthite ............ 1-78 0°55 none 618 The amount of potash may probably be taken as a measure of the sericitization, and this may explain why the porphyrite contains more albite than the porphyries. It appears to be the least seri- citized rock of those analysed. Some of the freshest specimens of the albite-porphyries should exceed 60 per cent. of albite, judging from the sections. 1 Bull, Geol. Sury. W. Austral. No. 6 (1902) p. 73. 660 DR. J. A. THOMSON ON THE [Dec. 1913, (1) The Jaspers and Graphitic Schists. An account of the petrology of Kalgoorlie would not be com- plete without some notice of the jasper-lodes and the bands of graphitic schist, which traverse rocks of almost every nature. Most of them run parallel to the foliation-planes of the enclosing rocks, but some are oblique, notably a strong jasper-lode east of Hannan’s Reward Mine in the ‘North End,’ which cuts the foliation-planes at an angle of 50°. The jaspers are light or dark siliceous rocks, generally with a fine banding which may be extravagantly contorted. The banding is due mainly to variations in the size of the grain of the quartz- mosaic of which the rocks are composed: it is not due to _bands containing different minerals, as in the case of the hematite- jaspers of other goldfields. Sections reveal little beyond a very fine quartz-mosaic containing small sporadic rhombohedra of carbonates or limonite pseudomorphs of the same. The jaspers are generally accompanied on each side by slaty rocks, which bear a close resemblance to ordinary sedimentary slates and phyllites, and similar rocks are also found replacing the jaspers along the strike. Few opportunities of tracing the down- ward continuation of the jaspers are available; but they appear in some cases to be replaced by graphitic schists (for imstance, in the North End Development G.M.L. 1731 E, and in the Union Jack G.M.L. 535 K). The band that has been most closely studied runs from the Boulder Main Reefs G.M. through the Great Boulder and Boulder No. 1 to the Golden Pyke G.M. and beyond. The outcrop can be traced in places by white slaty rocks, while jaspers and slaty rocks are seen in the railway-cutting east of the main shaft of Boulder No.1 G.M. At the 100-foot level from Philip’s Shaft in the Great; Boulder G.M., the band consists of white quartz-sericite schists. A section of one of these shows a very fine quartz-mosaic, with much fine schistose sericite, a few minute prisms of rutile, and small pseudomorphs of lmonite after pyrite or siderite. At greater depths this band is represented by graphitic schists, as may be seen at many places in the Great Boulder Mine. In section, the graphitic schists are almost opaque, from the presence of fine graphite dust and small crystals of pyrite; but the presence of quartz and sericite can generally be verified. A specimen from the eastern horing (from the main shaft at the 2350-foot level) contains quartz, carbonates, sericite, rutile, and clinochlore, in addition to graphite and pyrite. Wavy bands of sericite, deeply stained by fine graphite dust, wrap round clearer areas occupied by carbonates or by large pyrite-crystals enveloped by quartz and clinochlore. At several places within this band of graphitic schists the presence of albite-porphyry has been verified, but it does not appear to form a continuous dyke. The same association of porphyry and graphitic schist occurs at the 400-foot level of the Union-Jack Mine. The graphitic schists are sharply marked off from the quartz-carbonate-sericite schists in which they occur, and also from the albite-porphyry. It seems most probable that they have y Vol. 69.| PETROLOGY OF THE KALGOORLIE GOLDFIELD. 661 arisen from the schists and not from the porphyry; but the presence of the latter can hardly be accidental, for in a railway- cutting about 3 miles east of Ccalgardie Dr. Maclaren has observed an analogous phenomenon. A narrow dyke of quartz-porphyry is intrusive through an amphibolite, and on each side of the dyke there is a band of graphitic schists about 5 feet wide. Untor- tunately, neither the amphibolites nor the schists are fresh enough for microscopic study. The impregnation of schists with graphite is not confined to bands traversed by porphyry-dykes. It is found, for instance, along fault-planes in the cale-schists. There can be no doubt whatever that the schists are of igneous origin, and that the graphite is of inorganic origin. Probably it has arisen from emanations given off by the porphyry magma, although the exact mechanism of its formation remains obsenre. Although in some places the graphitic schists crop out at the surface without much alteration, in others they are oxidized to a depth of over 100 feet, giving rise at the surface to white quartz-sericite schists. To this. category, apparently, must be ascribed the rocks classed by Mr. Simpson as ‘ older sediments,’ of which three analyses have been made.’ The absence of contact- minerals in them militates against a theory of sedimentary origin for rocks so closely associated with intrusives, while the low mag- nesia and high soda percentages of the analyses make their deriva- tion from albitized rocks probable. The analyses are as follows:— XXXII. SNOXCXCUTE OXON: | SiO ee. 84-07 70°25 60:01 | TiO2 | 1:16 0°34) 0:05 | AROS Mata eae 9:03 15:22 17°82 | FeO; 0:42 1:00 0°54 EO Heras eee 0°45 0°87 1°65 MnO tr. tr | 0:09 MeO 024. 012 1°69 CaO O21 O14: 5°86 NEO One: 1°64 3°46 279 | TSS Mn se Re es tae 2:9, 1°28 1°85 | Hs0+ 1:05 1°34: 1°65 | H20 — 0:20 0°42 O15 CO 0:07 0:02 5°50 | Fes: . 0:04 DOom 188 Totals ...... 100°79 100°39 101°53 | Sys GAPS” send b adridescadeonl| 2°66 2°73 271 Analvst.......cecee-s--.| E. S. Simpson. | E. 8. Simpson. C. G. Gibson. | * Including 0°50 Cu. XXXII. G.S.M.1731. ‘Dark-grey slate’ from G.M.L. 917 EK, Paringa Con- solidated Mines, Ltd., Boulder. XXXII. G.S.M. 1732. ‘ Dark-grey sandstone’ from the same lease. XXXIV. G.S.M. 1739. ‘lLight-grey sandstone’ from the 400-foot level, G.M.L. sez0 Hi, Hawk’s View G.M., Kalgoorlie. y Bull. deol. ‘Surv. W. Rete No. 6 (1902) p. 77. Q.J.G.8. No. 276. 2x 662 DR. J. A. THOMSON ON THE (Dee. 1913, Whether the jasperoid rocks have arisen by a surface-silicification, as their absence in depth might suggest, or whether they are lenticular bodies following one another en échelon within the bands of graphitic schists, and thus not necessarily present in all cross-sections of the bands, cannot be decided on the evidence available. Dr. Lindgren! has suggested a deep-seated origin for the hematite-jaspers found in other goldfields of the State. LY. Rexarionsure oF tHE Rocks. While it is a matter for argument whether or not all the intrusive rocks from Kalgoorlie described above are related by differentiation from a common magma, they may be divided into groups, each of which consists only of members showing undoubted affinity one with the other. Group a consists of the quartz-dolerites, dolerites, hornblende- dolerites, and pyroxenites, The first three of these rocks form different parts of the same mass, and show gradations from one to the other. The pyroxenites, although found in separate intrusions, betray their relationship with the quartz-dolerite by the occa- sional presence of micropegmatite. This group will be termed in the subsequent discussion ‘the quartz-dolerite series.’ Group £ contains the porphyrites and albite -porphyries. These rocks form a well-defined series with almost every gradation between the extremes represented, and their close relationship cannot be doubted. Group y contains by exclusion the peridotites. Mr. Simpson” separated the last two groups from the first as ‘newer eruptives, his reasons being presumably that the albite- porphyries traverse the rocks of the quartz-dolerite series in well marked dykes, and that the serpentines of Hannan’s Lake are relatively little-altered igneous rocks as compared with the amphibolites. a) Relationsh1p of the Peridotites to the Quartz. Dolerite Series. 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Tiles —— LAT SOS pulibrary (Books and bindime, Ge.) 2.020.502... 238 12 9 PeLRLENsIOM On Wiley) eee chee: cscs. wo. gas hee ee IY) ss ee ,, Library-Catalogue : (Cnn dS) Shae Hace teteer Sa staae Bch a nciabe Hee epee CRBEE Le 2an'G (Connpilatvomwnee epee poeta eo nace acaclecn 50 0 0 ———. 61 2 6 ,, Publications: Quarterly Journal, Vol. Ixviii, Paper, Print- ing, and Illustrations...................-066 O92 LOO Postage on Journal, Addressing, etc. ...... 104 18 5 Record of Geological Literature ............ 1371389 Abstracts, including Postage ........ ...... 101 12 6 is trotMellowsl deat daccee se a. laude vo -c acest 49 8 9 ———— 1362 7 5 ,, Balance in the hands of the Bankers at. December 31st, 1912: @iirenteAccountyn sey ee nates eee 108 16 5 Deposit; Account 22.22.0285. 5.-.:2s-saseces 500 0 O ,, Balance in the hands of the Clerk at Mecempervolist VOM Meee Ce. ayy By 10) We have compared this Statement with the Books and Accounts presented to us, and find them to agree. HENRY A. ALLEN, ——— 641 2 3 £3893 7 9 HENRY DEWEY, ai BEDFORD McNEILL, Treasurer. January 25th, 1913. 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Vol. 69.] Statement relating to the Society’s Property : December 31st, 1912. SNE igh Balance in the Bankers’ hands, December 51st, 1912: : One CumrentveAccOunil sense reeeraasn. aac ssn eccees 108 16 5 Pe WD CMOSTE RM COs mpi cuin cudh tae vccgeed dsteienase 500 O O Balance in the Clerk’s hands, December 31st, 1912. 52 5 10 Due from Messrs. Longmans & Co., on account of the Quarterly Journal, Vol. LX VIII, etc. .. = ...... muneats on Admission-Fees 4)... ces. ss ees NGS) Sasi) Arrears of Annual Contributions .............. 254 2 Funded Property, at cost price :— . £2500 India 3 per cent. Stock ............ 2623 19 0 £300 London, Brighton, & South Coast Rail- way 5 per cent. Consolidated Preference SUTOGIR Rental nets atAiase ts Acacia Salat Seem Pe neg 502 15 3 £2250 London & North-Western Railway 4 per cent. Preference Stock ..........-- 2898 10 6 £2800 London & South-Western Railway _ 4 per cent. Preference Stock .......:.... 3607 7 6 £2072 Midland Railway 23 per cent. Per- petual) Preference Stock’: 0.0.5--.5.-.5+: 1850 19 6 £267 6s. 7d. Natal/d per cent. Stock... ..... 250 0 0 £2000 Canada 33 per cent. Stock .......... IS Shey ILE”) 40) xii Lisp ak Gy CLs Geil 367 10 O £1076 19 4 13,716 2 9 [Norn.—The above amount does not include the value of the Library, Furniture, and Stock of unsold Publications. The value of the Funded Property of the Society, at the prices ruling at the close of business on December 31st, 1912, amounted to £10,957 10s. 9d.| BEDFORD McNEILL, Treasurer. January 25th, 1913. xliyv PROCEEDINGS OF THE GEOLOGICAL society. | March 1913, AWARD OF THE WoLLAsron Mepat. In handing the Wollaston Medal, awarded to the Rev. Osmonp Fisoer, M.A., to Sir Arcuipatp Gerke, K.C.B., Pres. R.S., for transmission to the recipient, the Presipenr addressed him as follows :— : Sir ArcHipaLp Gerkrn,— More than forty years ago, in my earliest struggles with the elements of geology, I received much kindly encouragement from my revered teacher and relative, Osmond Fisher. ‘l'wenty years later it was my pleasure to follow his footsteps, and to profit by the closest scrutiny of his work, in the Isle of Purbeck. It is now my privilege to request you to forward to him, in accordance with a upanimous vote, the highest award which it is in the power of the Council of the Geological Society of London to bestow—the Wollaston Medal. -I have referred especially to his work on the Purbeck Beds, because it is that with which I have the closest acquaintance. Written as long ago as 1856, his paper on that remarkable group of strata has formed the basis of all subsequent investigations ; but no less masterly was his account of the Bracklesham Beds of the Isle of Wight Basin, which followed in 1862. The two together placed him at once in the ranks of those pioneer-geologists who, self-trained in all branches of their science, laid the foundations of British Stratigraphy. It is probable, however, that the name of Osmond Fisher will dwell in the memory of posterity more especially as that of the author of the ‘ Physics of the Earth’s Crust.’ First produced in 1881, that work was founded on geological reasoning and mathe- matical proof which it was within the power of few to appreciate. Its value, growing in recognition during the lapse of more than thirty years, is now acknowledged ; and the book has taken rank as a classic, on what is perhaps the most recondite subject which a geologist can be called on to investigate. It is needless to refer in detail to the papers on a variety of other subjects with which Mr. Fisher has enriched geological literature, for they have already been mentioned from this chair on the occasion of the presentation to him of the Murchison Medal. But to what was then said I will now add that we are rejoiced to ’ Vol. 6y.] ANNIVERSARY MEETING—WOLLASTON MEDAL. xlv see him still maintaining his interest in current geological work at the great age of 95, and that it is a satisfaction to us to add this further proof of our appreciation of his labours. Will you, therefore, be so good as to transmit this Wollaston Medal to Osmond Fisher as a recognition by the Council of the lasting value of his ‘researches concerning the mineral structure of the Earth ’ ? Sir ArcurpaLp Guixrn, in reply, said :-— Mr. PRestpEnt,— No duty at once more honourable and agreeable could be entrusted to a Fellow of this Society, than to act as a deputy for one of the most venerable and esteemed of our colleagues, and to receive on his behalf the Wollaston Medal, which has been awarded to him in recognition of the value and distinction of his contributions to Geological Science. I have been favoured with a short statement from Mr. Fisher, which I will read. ‘It is indeed a most gratifying surprise to me that the Council of the Geological Society should have considered me worthy of their highest honour, the Wollaston Medal. At my great age (95) I shall not be able to attend and to offer my'grateful thanksin person. I think that the Council must have formed a higher opinion of my merits than I have, but I must not quarrel with that. I once had as a pupil a scion of the Wollaston family. He was an entomologist, and wrote a learned work upon the insects of Madeira, He described the insect-remains which I found in Lexden brick-pit. ‘Tam thankful to say that I am still able to take an interest in our science. Jam engaged at present in a mathematical investigation of the effect of an elevated plateau, like the Himalayan, wlien below the horizon ofa station, in increasing gravity there. It will have to be taken account of in drawing con- clusions from observations on gravity in the plains of India. My friend Davison is helping me with the arithmetic, in which I cannot trust myself. Arithmetic was not taught at Hton when I' was there. I am afraid that the chief interest in my problem will be mathematical. In all problems of attrac- tion hitherto the curvature of the earth’s surface has been neglected. J have taken account of it, I believe, for the first time.’ In receiving this Medal for transmission to our revered Associate, I should like to add an expression of my own indebtedness to the illuminating suggestiveness and clear presentation of his contribu- tions to Physical Geology. It is astonishing and delightful to see him, at his adyanced age, still full of mental alertness and enthu- siasm, busy as ever in the continuation of the long series of mathe- matical investigations with which he has enriched geological xlvi PROCEEDINGS OF THE GEOLOGICAL sociETy. [ March 1913, literature. He has set to all of us a noble example of modest, earnest, and unwearied devotion to the cause of our favourite science. Let us trust that the brave veteran may not only live to complete the research on which he tells us that he is engaged, but prolong for years to come his sunny and beneficent old age. AWARD oF THE Murcutson Mepat. The Presipenr then presented the Murchison Medal to Mr. Grorez Barrow, F.G.S., addressing him in the following words :— Mr. Barrow,— It is a great pleasure to me to hand to one who has been my colleague for many years, a tribute paid by the Council of the Geological Society to a life spent in the furtherance of Geological Science. In awarding to you the Murchison Medal they have borne in mind that you commenced your official career by investigations of a part of Yorkshire remarkable both for the development of Lower Mesozoic rocks and for its physical features, and by writing a terse and lucid account of it in the North Cleveland memoir. They remember, too, that after assisting in the mapping of the West Yorkshire dales, you proceeded to the Scottish Highlands, and that by there introducing modern petrographical methods, you obtained results which have left a permanent mark in the literature on that fertile source of geological controversy. Your paper in 1893 on an intrusion of muscovite-biotite-gneiss has taken high rank, not only as a storehouse of careful observations on the characters of igneous and metamorphic rocks, but as elucidating the problems connected with hypogene geology. It was followed by announcements of your discovery of chloritoid in Kincardineshire and of the possible occur- rence of Silurian strata in Forfarshire ; while in 1904 you threw much light on the difficult question of the relationship of the Moine Gneisses of Perthshire to the metamorphic rocks of other parts of Scotland. On your transference to Devon and Cornwall the experience which you had gained was utilized in unravelling the structure of that tormented region, and in studying the phenomena presented by the ’ Vol. 69. | ANNIVERSARY MEETING—LYELL MEDAL xlvit metamorphic aureoles round the granitic intrusions. Here also your paper on the high-level platform of Bodmin Moor proved that more recent phenomena were not escaping your attention. At the present time, the work upon which you are engaged in Warwick- shire is already throwing much light on some obscure stratigraphy. Will you allow me, as an old colleague who has had every opportunity of judging, to add my own testimony that your work, wherever you have been placed, has been characterized by that thoroughness and conscientiousness in the field which alone can lead to permanent advance in the interpretation of geological phenomena ? On behalf of the Council I beg you to accept this Medal and Award. Mr. Barrow, in reply, said :— Mr. Presipenr,— I feel deeply the honour which the Society has conferred on me by the award of the Murchison Medal. I have spent many years werking on those Highland rocks in which the founder of this Medal took so keen an interest. The Murchison Medal has now been awarded to several workers on these rocks, and as no two of us have come to the same conclusions, it is gratifying to feel that the Fellows of this Society can rely implicitly on the impartiality of its Council in its awards. I have to thank you very much for the kindly way in which you haye spoken of my work; it is especially agreeable, as coming from an old colleague and the head of that branch of the service to which I belong, which makes it a special pleasure to receive the Medal from your hands. Awarp or top Lyett Mepat. In presenting the Lyell Medal to Mr. 8. 8. Buckman, F.G.S., the PrestpEnt addressed him as follows :— Mr. Buckmayn,— The Lyell Medal is by custom associated more especially with paleontological research. It is, therefore, fittingly awarded to you,. in recognition of the conspicuous place which you hold among British paleontologis‘s, as regards both your intimate knowledge of species. xlvili PROCEEDINGS OF THE GEOLOGICAL society. [March 1913, and your philosophic treatment of your subject. While you are an eminent exponent of that school of thought and mode of study with which the name of Hyatt is associated, your own work exhibits a marked originality and independence of outlook. Moreover, not only is it pregnant with suggestive ideas, but it forms an example of pure scientific research having proved to be of value in practical application. Your investigations on the genetic relationships of the Jurassic Ammonites are the best example of your specialized labours. In a great monograph on the Ammonites of the Inferior Oolite Series, and in other works, you have sought to apply with precision the principles which underlie the correlations between ontogenetic and phylogenetic growth. Your research among the Brachiopods is no less illuminating as an example of the application of evolutionary principles; and, in dealing with the fossil forms, you have illustrated the production of similar morphic sequences in separate stocks and the frequency of homceomorphy. The zonal method has been applied by you to stratigraphical problems with exceptional minuteness and accuracy. So great is your experience in handling difficult questions of zonal correlation, that you have acquired powers of interpretation which seem almost instinctive. From my own knowledge I can speak of the value of your services in revising collections in public museums, and in converting -mere accumulations of fossils into orderly sequences, eminently instructive as regards both evolution of species and stratigraphical significance. It is my privilege to hand to you this Medal and Award in recognition of brilliant and original paleontological research. Mr. Bucxmay, in reply; said :— Mr. PResipent,— It is with feelings of very great pleasure that I receive the un- expected honour of the Lyell Medal awarded to me by the Council ; and when I listened to your kindly references to my work I felt that your recognition of its merits was far too flattering, especially when so much of what I hoped to accomplish still remains undone owing to certain causes. But it gives me particular pleasure to receive this award from your hands, for you belong to a body of ’ Vol. 69.] ANNIVERSARY MEETING—BIGSBY MEDAL. xlix ‘scientific men whose practical work in geological surveying enables them to judge the value of stratigraphical labours. It is now 32 years since the Society did me the honour to accept a paper from my pen.. My later work has followed that paper up, though in more detail in the nomenclature both of strata and of species. But my later workis guided by my interest in the study of evolution, good illustrative subjects being found among Ammonites and Brachiopoda. This stratigraphic and classificatory work was, and is the necessary, if somewhat monotonous spade-work for evolution; for it was useless to compile genealogies while the -sequence of strata was unknown in detail, and while nomenclature included polyphyletic forms under the same designation, Through attention {to, and insistence on, the importance of apparently trivial details, the phenomenon of homceomorphy was discovered; and the reception accorded to homceomorphy has, at any rate, been cordial. But it involves a revision, almost a rewriting, of paleontology. Much of my earlier work I have ‘revised ; much of it I should like to rewrite. Such spade-work finds perhaps its fullest expression in the publication ‘ Yorkshire 'ype-Ammonites’; for the bed-rock of nomenclature must be an exact knowledge of types. And I cannot let this opportunity pass without acknowledging the debt which I owe to my enthusiastic collaborator, Mr. J. W. Tutcher, who com- bines an excellent geological knowledge with unrivalled photographic skill. His work has been the making of that publication. To you, Sir, and to the Council I tender my heartfelt thanks for an Award which encourages me to continue my researches. AWARD oF tHE Brespy Mupat. The Presipent then presented the Bigsby Medal to Sir Tuomas Henry Hornanp, K.C.1.E., addressing him in the following words :— Sir Tuomas Hottany,— The Council have awarded to you the Bigsby Medal in recognition of the eminent services which you have rendered to Geology, more especially during your tenure of office in India. Appointed to the Geological Survey of India in 1890, you proceeded to enrich the “Records’ and other publications, not only with papers on petrological VOL. LXIX. d 1 PROCEEDINGS OF THE GEOLOGICAL soctery. {March 1913,. and other scientific questions, but with the discussion of problems- more directly bearing on the welfare and safety of the inhabitants of India. Under your Directorship, from 1903 to 1909, the Geological Survey of India maintained its high reputation ; while, at the same time, advantage was taken of your sagacity and extended geological experience to obtain your advice in the administration of Indian scientific affairs. Itis not possible for me to refer in detail to your published works. They range through petrology, mineralogy, stratigraphy, and seis- mology into the domain of geography, one of your later papers having been devoted to an account of the remarkable dissemination of salt which can be effected by wind. But I may emphasize, in the words of the founder of this Medal, the fact that you are not too young to have done much, and that you are not too old for further work. It is the hope of the Council that you will continue for many years at home the eminently useful career which you have commenced so auspiciously in India. Sir THomas Horanp replied as follows :— I deeply appreciate the honour which has been conferred on me by the Council, as well as the generous terms in which you, Sir, have referred to my work. Nothing could be more pleasing to a worker than to be enjoined by one’s seniors to continue in work. A glance over the list of my distinguished predecessors shows how abundantly each one subsequently fulfilled the intention of this Award, and thus one’s feelings of satisfaction become tinged. with those of great responsibility. At the same time, when one realizes that the Council hitherto has never made a mistake in its selection of a recipient for the Bigsby Medal, this feeling of responsibility becomes again blended with that of hopeful ambition. In so far as this honour is a recognition of work already done, T should like to make it known to the Council that my chief aims in India have been to facilitate the work of my colleagues. No published work of my own has caused me more anxious care, or given me greater satisfaction, than the memoirs issued in the names of my colleagues on the Geological Survey of India; it was because of their abundantly loyal support that a measure of success followed my administration, and it is because this honour in effect recognizes. their good work, that it gives me peculiar pleasure. é Vol. 69.] ANNIVERSARY MEETING—MURCHISON FUND. li AWARD FROM THE Woxtaston Donation Funp. In presenting the Balance of the Proceeds of the Wollaston Donation Fund to Mr. Witttam Wicxuam Kine, F.G.S., the PresipEnt addressed him as follows :-— Mr. Wicknau Kine,— The Council have awarded to you the Wollaston Fund, to mark more especially their appreciation of your researches on the Permian Conglomerates of the Lower Severn Basin. Probably no group of british deposits called more urgently for investigation than the red rocks of the Midlands. Their remarkable conglomerates, breccias, and calcareous bands offered problems of the greatest interest ; while the stratigraphical sequence and correlation through- out the country called for reconsideration. Though the story is not yet fully told, your paper marked a notable advance in its elucidation ; the Permian breccias of the Severn valley are in- separably connected in men’s minds with your name. The Council are aware that you are engaged upon other problems connected with the district in which you have laboured to such advantage, and make this Award, not only in recognition of what you have done, but in anticipation of equally good work to follow. AWARD FRom THE Murcuison Groxnoeicat Funp. The PresipEnt then presented the Balance of the Proceeds of the Murchison Geological Fund to Mr. Ernest Epwarp Lestiz Drxon, B.Sc., addressing him in the following words :— Mr. Drxon,— The Murchison Fund has been awarded to you by the Council of our Society to mark their sense of the value of your detailed observations on the Carboniferous Limestone. Working in associ- ation with Dr. Vaughan, and armed with the knowledge which you had gained during your official survey of the region, you were able to combine detailed paleontological and stratigraphical observations in such a manner as to produce an exhaustive account of the varying geographical conditions under which the limestone of Gower came into existence. You have also provided us with an admirable d 2 hi PROCEEDINGS OF THE GEOLOGICAL society. [ March 1913, account, founded in part upon your own observations, of a remarkable overthrust exhibited in the Pyrenees. May I be per- mitted to add, from my own knowledge of a colleague with whom I have long been associated, my testimony to your zeal and to that earefulness in field-work which leaves no stone unturned and no note unmade? The Council in making this Award, anticipate with confidence further results from your labours. AWARD FROM THE LyELL GroLogicaL Funp. In presenting the Balance of the Proceeds of the Lyell Geological Fund to Mr. Lrewettyn Treacupr, F.G.S., the Present addressed him as follows :— Mr. Treacurr,— The Council have awarded to you the Lyell Fund in recognition of the value of your contributions on the Chalk. In 1905, in association with Mr. Osborne White, you were able to add greatly to our knowledge of the fauna and zonal affinities of the Taplow phosphatic chalk. In the following year, with the same collabo- rator, you described some occurrences in Berkshire of phosphatic chalk not previously known, and also published the result of your joint investigations on the Upper Chalk of the western end of the London Basin, showing in detail the extent of the Tertiary trans- gression. While thus engaged you have not omitted to collect the relics which Neolithic and Paleolithic men have left in the Thames Valley. For my own part, I take this opportunity of acknowledging the great utility of such observations as yours in the work of the Geological Survey. We look forward to the continuance of your researches. — AWARDS FROM THE Bartow-JAMEson Funp. The Presippyr then presented a moiety of the Proceeds of the Barlow-Jameson Fund to Bernard Sir, M.A., addressing him as follows :— Mr. Surru,— In awarding to you a part of the Barlow-Jameson Fund, the Council have borne in mind that our knowledge of the Glacial phenomena of Black Combe is largely due to your researches. In your admirable account of that region every branch of the enquiry y Vol. 69.] ANNIVERSARY MEETING —BARLOW-JAMESON FUND. lila has received due consideration; but your description of channels now for the most part abandoned, though occupied during the Glacial Period by marginal streams or overflows, forms a special feature of your paper. In the course of your official work in Nottingham- shire you made good use of your opportunities to study the remark- able skerry-bands of the Keuper Marl, and found reason to connect their formation with the variations of the seasons. Lower Palo- zoic rocks also have engaged your attention in Ireland. . This Award has been made in the expectation that you will continue the career so well begun, and will do yet more ‘ for the advancement of Geological Science.’ In handing the other moiety of the Proceeds of the Barlow- Jameson Fund, awarded to Joun Brooxn Scrivenor, M.A., to Mr. Cremenr Rei, F.R.S., for transmission to the recipient, the Presrpenr addressed him in the following words :— Mr. Rerp,—— In the course of a rapid journey in Patagonia, Mr. Scrivenor found time to make observations on the sedimentary and igneous rocks and on the river-system of that country. From 1902, as a member of the staff of the Geological Survey, he was associated with you in Cornwall, and rendered valuable assistance in preparing the maps and memoirs illustrating the country around Newquay and the Land’s End. In 1905 he was selected as Government Geologist in the Federated Malay States, and since his appointment has enriched our knowledge of that difficult region by papers on the mode of occurrence and mining of geld, tin, copper, and other ores, by descriptions of Archzan and igneous rocks, and by re- searches on the sedimentary sequence. Both in range of subject and in extent of travel he has distinguished himself as one of our leading exponents of the geology of the more distant parts of the Empire. In transmitting to him a part of the Barlow-Jameson Fund, will you assure him that we at home watch with interest the work of our colleagues abroad, and will you express on our behalf the hope that he may long preserve the energy necessary for the prosecution of such arduous labours ? liv » PROCEEDINGS OF THE GEOLOGICAL society. {March 1913, THE ANNIVERSARY ADDRESS OF THE PRESIDENT, Ausrey Strauan, Sc.D., F.R.S. Since our last Annual Meeting we have lost by death no fewer than six distinguished foreign geologists, Prof. Brush and Prof. Zirkel from our list of Foreign Members, and Prof. Forel, Prof. von Koken, Prof. K. de Khrushchov, and Prof. Tarr from among our Foreign Correspondents. We have to mourn also the decease of twenty-eight Fellows of the Society, and among them many who had done much to advance geological science. Though they were not Fellows of the Geological Society, I may be permitted to allude also to the deaths of five members of the British Antarctic Expedition—Scott, Wilson, Bowers, Oates, and Evans—on their return journey after attaining the South Pole. The details of the tragedy and the indomitable fortitude displayed by these men are known to you, but I will remind you of one incident. We learn that they had collected geological specimens, and that they carried them, after food and fuel had gone, until life gave out. Surely never before have inanimate objects been invested with so pathetic an interest. In preparing the following obituary notices | am indebted for assistance to Dr. J. J. H. Teall, Mr. L. J. Spencer, Prof. E. J. Garwood, Dr. A. Smith Woodward, Mr. G. W. Lamplugh, Dr. J. Horne, Mr. H. W. Monckton, Mr. R. D. Oldham, and Mr. John Gerrard. [For the data on which the following notice is founded I am indebted to an obituary published in the ‘ American Journal of Science’ ser. 4, vol. xxxiii, p. 389.] ; Grorcs Jarvis Brus was born on December 1d5th, 1831. While yet at school he developed, under the guidance of an enlightened master, a taste for mineralogy which he maintained for the rest of his life. After a brief period spent in business, he was compelled by an illness to seek a more open-air life. Having acquired an interest in farming, he studied agriculture and applied chemistry at Yale, and in 1850 became assistant-instructor in chemistry and toxicology at Louisville (Kentucky). In 1852-53, while assis- tant in chemistry at the University of Virginia, he published, in collaboration with Mr. J. Lawrence Smith, three papers on the “ Re-examination of American Minerals.’ Feeling the necessity of a Vol. 69. | ANNIVERSARY ADDRESS OF THE PRESIDENT. lv further study he then went to Germany, and, on receiving an appointment as Professor of Metallurgy in the Yale Scientific School in 1855, extended his experience by studying at the Royal School of Mines, London, and by visiting the chief mines and smelting- works of Great Britain and the Continent. The scientific department of Yale College, which had lacked both funds and organization, was enriched in 1860 by the liberality of Mr. Joseph KE. Sheffield, and became known as the Sheffield Scientific School. To its organization Prof. Brush thenceforward devoted his great administrative abilities; but, although as Secretary, Treasurer, and eventually President of the Board, he took a leading part in its affairs, he maintained to the last his interest in the subject in which he had specialized as a boy. His collection of minerals became notable for its completeness for the purposes of scientific study, and for the care with which it was arranged and catalogued. It was presented to the Sheftield Scientific School in 1904, and will remain at Yale as a permanent monument to its founder. Among his published works mention must be made of the ‘Manual of Determinative Mineralogy.’ He contributed also ? largely to Dana’s ‘System of Mineralogy,’ and in his presidential address to the American Association for the Advancement of Science at Montreal in 1882, he summarized the early history of American Mineralogy. He was elected a Foreign Correspondent of this Society in 1877, and a Foreign Member in 1894, Previously, in 1868, he had been elected a member of the National Academy of Sciences ; and in 1886 he received the degree of Doctor of Laws at Harvard. He died on February 6th, 1912, in the 81st year of an eminently active and useful life. By the death of Geheimrath Professor FErRprnaND ZiRKEL, the geological world has lost a pioneer in the science of microscopical petrography, and the Geological Society one of its oldest and most distinguished Foreign Members. He was born at Bonn on May 20th, 1838; and, although the greater part of his long and active life was spent away from that city, he always regarded it as his home, re- turning to it whenever his professorial and other duties permitted. In 1855 Zirkel entered the University of Bonn, applying him- self especially to chemistry and mineralogy, and to practical work in the mines of Rhineland, with a view to the career of a mining engineer. But, before he had completed his studies, the opportunity lvi PROCEEDINGS OF THE GEOLOGICAL socinty. {March 19173,. of making a tour in Iceland and the Farve Islands proved too tempting to be resisted. On returning from this tour he spent three months in Scotland and England, visiting some of our most important mining districts. He graduated at Bonn in 1861, making his observations in Iceland the subject of his inaugural dissertation. | We next find him working for a short time in Vienna, where his- first important paper on microscopical petrography was published in 1862. By this time he had recognized the importance of Sorby’s. researches and the far-reaching possibilities of the new method of investigation. In 1865 he became Professor at Lemberg. In 1868 he received a call to Kiel; and two years later (1870) to Leipzig, as suecessor to Karl Friedrich Naumann, the celebrated mineralogist. There he remained for nearly forty years, attracting students from all parts of the world by the excellence of his teaching and the charm of his- personality. This is not the occasion on which to refer in detail to his. numerous original publications ; two may, however, be mentioned, as being of especial interest to British and American geologists. In 1868 he made an extensive tour along the western coast of Scotland, visiting Arran, Mull, Iona, Staffa, and Skye, and collecting an ex- tensive series of rocks for more minute study in the laboratory. The results of his observations, in which the microscope was applied to the study of the igneous rocks cf that region, were published in 1871. Shortly after the appearance of this paper, Zirkel’s services. were secured by the United States Government for the examination and description of the rocks collected during the Geological Explora- tion of the Fortieth Parallel. This resulted in the publication, in 1876, of the large quarto volume on Microscopical Petrography, which forms vol. iy of the Geological Report by Clarence King. The importance of the new method was now recognized all the world over, and communications based on it were appearing in the scientific periodicals of many lands. With this rapidly increasing mass of petrological literature Zirkel made himself thoroughly familiar, finally giving to the world the results of his unrivalled. knowledge in the second edition of the ‘ Lehrbuch’ (1895-94), the first edition of which had appeared in 1866. This is an encyclo- peedic work published in three large volumes. Although Zirkel is best known as a petroloegist, his services to pure mineralogy must not be overlooked. In 1862 he brought out é Vol. 69. | ANNIVERSARY ADDRESS OF THE PRESIDENT. lyin an important monograph on bournonite ; and, after succeeding to the chair at Leipzig, he accepted the responsibility of keeping Naumann’s well-known. textbook up to date. This work has passed through fifteen editions, six of which have been edited by Zirkel. Our late Foreign Member often visited this country, where he had many personal friends, including Sorby, to whom he dedicated his classic work on the ‘ Microscopic Structure & Composition of Basalts ’ (1870). He was a man of sympathetic nature, a delightful companion, and a true friend. He took a deep personal interest in the welfare of his students, and they responded with almost filial affection. He received many honours from universities, scientific institutions, and from the State. His colleagues showed their regard for him by making him Rector of the University with which he was officially connected for so many years. Zirkel was elected a Foreign Correspondent of the Geological Society in 1869, and a Foreign Member in 1880. In 1897 he was elected a Foreign Member of the Royal Society. He died at Bonn on June 11th, 1912, in the 75th year of hisage. [J.J.H. T.] By the death of FRancors AtpHonsE Fornt, who was elected a Foreign Correspondent in 1910, our Society has lost a naturalist of world-wide renown and one of the notable Swiss savants of the last half-century. He was born at Morges on February 2nd, 1841, on the shores of the lake to the investigation of which he was to devote so many years of his life. He was educated at the Academy of Geneva, and attended the medical course at Montpellier. Atter a lengthened stay in Paris he proceeded to the University of Wiurzburg, where he took his Doctorate of Medicine in 1867, afterwards remaining there as prosector in the Department of Anatomy. In 1870 he returned to Switzerland, and was appointed Professor of Anatomy & Physiology in the University of Lausanne, a post which he held for 25 years. He retired from this chair in 1895, in order that he might pursue his favourite studies in various branches of natural philosophy. In the preface to his famous monograph on the Lake of Geneva he tells us how, at the age of thirteen, an interest in natural objects was first aroused in him by his father, in connexion » with the investigation of the lake-dwellings of Morges, then in course of excavation. . lviii PROCEEDINGS OF THE GEOLOGICAL socinty. | March 1913, During a period of nearly half a century, Forel had accumulated observations ranging over almost every branch of science. This catholic quality is well seen in the titles of his published papers, which exceed 300 in number and include, among other subjects, limnology, glaciology, seismology, meteorology, natural history, archeology, history, and biography. His chief work, ‘Le Léman,’ the three volumes of which appeared respectively in 1892, 1896, and 1904, treats of almost every branch of physical science and also biology, history, and political economy. It is impossible to touch here on more than one or two of the chief results arrived at by Forel in this remarkable work. In his chapter on the ‘ Origin of the Lake’ he does not accept the view that the lake-basin owes its genesis to glacial excavation, but considers that the greater number of large Alpine lakes were in existence before the Pliocene Epoch, and were inhabited by faunas similar to those which we find at the present day. He favours, on the whole, the view first suggested by Charpentier, and afterwards developed by Heim, that a subsidence eccurred during the Pleistocene Epoch which caused a reversed dip in the Alpine valleys, thus giving rise to sub-Alpine lakes. Among other notable results arising from his investigation of lakes was the discovery of a numerous and varied fauna living in the mud ‘even at the greatest depths, not only in the Lake of Geneva, but in the other large Swiss and Italian lakes. To the investigation of ‘problems connected with lakes he gave the name Limnology, and read a paper on this subject at the 6th International Geographical Congress in London, in 1896. In 1901 he published his admirable “ Handbuch der Seenkunde.’ One branch of imnology to which Forel contributed largely was ‘the investigation of seiches. By means of a special tide-gauge he was able to show that in the water of the lake rhythmical movements take place, comparable to the movements of a pendulum. He showed that a connexion exists between seiches and the move- ments of the atmosphere, and he was still engaged in speculating on the causes of these phenomena within a few days of his death. For the study of the varying colours of lake-water he invented a ‘scale of colours or ‘xanthometer’: this consisted of eleven tubes containing varying mixtures of sulphate of iron and bichromate of potash, by means of which he obtained a series of tints varying from azure-blue, through green, to yellow. After the year 1871, and especially between 1880 and 1890, his interest was aroused in questions relating to the structures and y Vol. 69.| ANNIVERSARY ADDRESS OF THE PRESLDEN’. lx motion of Swiss glaciers, and on this subject he contributed a series of papers to the ‘ Archives des Sciences Physiques & Naturelles de Geneve.’ As a result of these studies, he was led to investigate the granular structures of ice; to these attention had been first called by Hugi in 18438, but they had not been sufficiently considered in the controversies on the cause of glacier-motion during the middle and latter part of last century. In his paper on ‘Le Grain du Glacier,’ Forel laid stress on the marked increase in the size of grain which is observable between the névé and the terminal front of a glacier, and enunciated a ‘ grain-growth theory’ which, however, he subsequently saw reason to abandon. During his researches he was led to speculate on the causes which controlled the periodic advance and retreat of the Swiss glaciers. It is thanks to him, indeed, that the variations of the Swiss glaciers have been studied since 1880, and that since 1895 an International Commission on Glaciers has been founded which has extended its observations to other lands, including Scandinavia, India, America, and even the Arctic and Antarctic regions. In all, Forel contributed upwards of fifty papers on this subject alone, and between 1883 and 1895 he edited the reports on Glacial Variation which appeared in the pages of the Journal of the Swiss Alpine Club. As a result of his researches on seiches, Forel was led to take an interest in seismological phenomena, and, throwing him- self with his usual enthusiasm into this new subject, he founded in 1878, in association with Hagenbach and Heim, the Swiss Commission for the study of earthquakes. In 1882 he constructed a scale for measuring the degree of intensity of earthquake-shocks, which was almost identical with one suggested at the same time by Prof. De Rossi of Rome. These two scales have since been combined by seismologists, and are known by the name of the “ Rossi-Forel scale.’ In meteorology Forel was among the first to point out the connexion between the accumulated temperatures of the year and the amount of sugar present in grapes; in archeology and history his name is well known, especially in connexion with investigations on the Lake-Dwellers or ‘palafittures, to quote the name by which he designated these prehistoric peoples, and he was one of the founders of the Société Vaudoise d’Histoire & d’Archéologie, to which he contributed several papers. His researches also led him to the study of mirage, and his last communication to the Paris Academy of Sciences, on November 27th, 1911, when he was in his 72nd year, dealt with the fata lx PROCEEDINGS OF THE GEOLOGICAL society. [ March 1913, morgana which he had observed on the Lake of Geneva and the Mediterranean. He was Life Member of the Société Helvétique des Sciences Naturelles, of which he had been an ordinary member since 1864; an Honorary Member of the Société Vaudoise, of which he had also been an ordinary member since 1864; an Honorary Professor of the University of Lausanne, on his retirement from the chair of Ana- tomy & Physiology; a Doctor honoris causa of the University of Geneva; an Honorary Member of the Société des Sciences Naturelles of Bale; the first recipient of the Wiliiam Huber Prize awarded by the Société Géographique de France: and a recipient of the Order of the Crown of Wiirtemberg. He was elected a Foreign Correspondent of this Society in 1910, and he was also an honorary member of both the Swiss Alpine Club and the British Alpine Club.? [eRsepeiex Graal Ernst von Koxey was born at Brunswick on May 29th, 1860, and studied in the Universities of Gottingen, Ztirich, and Berlin. He graduated at Berlin in 1884, and in the following year he became assistant to Prof. Beyrich in the Geological Institute of the University. At that time the rocks, minerals, and fossils were being removed from the old University buildings to the new Museum of Natural History, and Koken was associated with Dames in the laborious task of re-arranging the collection in the new cases and cabinets. In 1890 he was appointed Professor of Geology & Mineralogy in the University of Konigsberg, and in 1895 he removed to Tiibingen, where he held the corresponding Professorship until his death on November 21st, 1912. Though interested in all branches of geological science, Koken devoted himself especially to paleontology and the use of fossils in stratigraphy. His Inaugural Dissertation in 1884 was the first serious attempt to identify the otoliths of bony fishes which are common in some Tertiary formations, and in 1888 and 1891 he made two more valuable contributions to the same _ subject. Among other early researches may also be mentioned his work on the reptilian remains from North German Wealden and Cretaceous formations, with important observations on the Mesozoic crocodiles. From 1899 onwards he devoted much attention to the Paleozoic gastropods, and published several papers noteworthy for the philo- 1 We are indebted to the courtesy of Prof. Dr. Henri Blane for much of the information embodied in this obituary notice. 4 Vol. 69.| ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixi sophical treatment of these fossils. After becoming Professer in Tubingen, he studied industriously the geology of Wiirtemberg, while still continuing his paleontological work ; and a visit to the Salt Range in India in 1902 led him to take a special interest in Permo-Triassic problems. He contributed a remarkable, though somewhat speculative paper on the Permian ice-age to the centenary volume of the ‘ Neues Jahrbuch’ in 1907. A complete list of, his writings 1s published in the ‘Neues Jahrbuch’ for 1912, vol. ii, pt. 3. While occupied with these numerous researches and his ordinary professorial duties, Koken was an editor of the ‘ Neues Jahrbuch ’ and the ‘Geologische & Paleontologische Abhandlungen’ from 1899, as also of the ‘ Paleeontographica’ from 1904, until his death. He planned and arranged the fine new Geological Institute of the University of Tubingen which was completed in 1902, and made extensive additions to the collection by his own field-work both at home and abroad. He. was beloved by his students and all his associates, who deplore his untimely loss. He was elected a Foreign Correspondent of the Geological Society in 1900. (A. 8. W.] Konstantin Duirrievich Kurusacnov (C. ps CurustscHorr), who was elected a Foreign Correspondent of this Society in 1895, died on April 19th, 1912. His work on the artificial reproduction of minerals, by which he is best known, extended over a quarter of a century (1870-1895). It was commenced in Breslau, con- tinued for a time in 1872 at the School of Mines in New York, and again in Breslau until 1890. He had studied also at Leipzig _and Heidelberg, but he took his degree of doctor at Breslau. On his return to Russia in 1890 he was attached to the Chemical Laboratory, and afterwards to the Mineralogical Museum of the Imperial Academy of Sciences of St. Petersburg. From 1895 onwards he was Professor of Geology & Mineralogy in the Military Medical Academy at St. Petersburg. His first paper ‘ On Silicic Acid & the Silicitication of Woods,’ in which he gave a preliminary account of his work on the artificial formation of crystallized silica, was published in 1872 in the “ American Chemist.’ Then followed a pamphlet (Wirzburg, 1878) giving the results, mainly petrographical, of a visit of several months’ duration in 1873 to the Cerro del Mercado (or Iron Mountain), near Durango in Mexico. In succeeding years a series of mineralogical xii PROCEKDINGS OF THE GEOLOGICAL society. [March 1913, and petrographical papers, some fifty in number, appeared under his name in French and German periodicals, principally in the Bulletin of the French Mineralogical Society (of which society he was a member), and in ‘Tschermak’s Mineralogische & Petro- graphische Mitteilungen.” Many cf these papers were well illus- trated by the author’s own drawings, made under the microscope- In 1894 a lengthy monograph on spheroidal (orbicular) structures in holocrystalline rocks (granite, diorite, and gabbro) appeared in the Memoirs of the St. Petersburg Academy. His last paper, published in 1895, related to an improved form of the Babinet compensator for determining the strength of double refraction of mineral sections under the microscope. The minerals which he prepared artificially include quartz, tridymite, and cristobalite (the three crystalline forms of silica), spinel, zircon, orthoclase, amphibole, diopside, biotite, analcite, and diamond. His method consisted in heating a dialysed solution of silica, together with various hydroxides, in. a specially-constructed steel bomb at high temperatures (250° to 550° C.) for several months. Diamond was obtained in 1893 from a solution of carbon in molten silver. Of other published work, mention may be made of his investi- gation and detailed descriptions of the inclusions in rock-forming minerals, and more especially the secondary glass-inclusions found in the minerals of certain rocks that had been caught up and acted upon by igneous magmas. ‘The spectroscopic analysis of minerals and the chemical analysis of rare-earth minerals were also matters that engaged his attention. Petrographical work consisted in the description of material collected by him in America (including a leucite-rock from Lower California, Mexico), Volhynia, and Lake Ladoga. [L. J.8.] By the sudden death of Rate Srockman Tarr on March 21st, 1912, at the untimely age of 48, the Society lost an esteemed Foreign Correspondent, elected so recently as 1909, who had many personal friends in this country and was held by them in deep respect for his admirable qualities of character as well as for his high scientific attainments. Born at Gloucester (Mass.), Tarr entered at Harvard University in 1881, and, after enforced interruptions for practical service in marine zoology and in geological field-work, he graduated in 1891. In 1892 he was appointed Assistant Professor of Dynamic Geology ’ Vol. 69. } ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixili and Physical Geography at Cornell University, and Professor of the same subjects there in 1896, occupying the chair of Physical Geography up to the time of his death. As an inspiring and sympathetic teacher, his influence upon his students was great, and has been acknowledged by them in many touching tributes to his memory. He was the author of some excellent textbooks of physical geography, geology, and economic geology, which have had wide circulation in this country as well as in America. In 1896 Tarr had charge of the Cornell Expedition to Greenland, and wrote a series of illuminating papers on the glacial phenomena of the district visited. In 1905-1906 he undertook researches in Alaska, in collaboration with his brother-in-law (Prof. L. Martin) and other assistants, for the United States Geological Survey, summarizing the results in 1909 in a monograph on the physiography and glacial geology of the Yakntat-Bay region, which is well known as a mine of information for all interested in glacial geology. Returning with Prof. Martin to the same district in 1909 and 1911, under the auspices of the National Geographic Society, to study the startling changes in pro- gress in many of the Alaskan glaciers, he again proved his high capacity as observer and explorer, and his journey to Spitsbergen with the International Geological Congress party in 1910 gave him further experience of glacial phenomena. His vivid description of the spasmodic advances in many of the Alaskan glaciers, which he attributed to the after-effects of the big earthquake that shook the region in 1899, raised new problems in the physics of ice. These problems he set himself to solve, and had begun a series of experi- ments on the properties of ice, which were actively prosecuted up to his last days, and of which the first fruits were published shortly before his death. A fine monograph by Tarr & Martin on the physiographical results of the 1899 earthquake in the Yakutat-Bay region was published posthumously by the United States Geological Survey last year. Cut down in the midst of his work and in the plenitude of his powers, Tarr had already done much and had planned to do more. The loss to science is heavy, and to his personal friends irreparable. He was married in 1892, and leaves a widow and two children. [G. W. LJ By the death of Ramsay Huartey Traquair the Society has lost one of its most distinguished Fellows and one of the prominent leaders in fossil ichthyology. Born at the Manse, Rhynd (Perth- Ixiv PROCEEDINGS OF THE GEOLOGICAL society. [ March 1913, shire), in 1840, he received his early education in Edinburgh, where, as a boy, he showed his bent towards natural science. He became a collector of shells, butterflies and moths, and he strolled along the sea-shore to examine the rocks. He was wont to relate that his keen interest in fossil fishes was first aroused when hammering the ironstone-nodules in the Wardie Shales, which revealed to him a fragment of a Palsoniscid fish. Thereafter he passed through the medical curriculum at the University of Edinburgh, and graduated in medicine. His skill as a dissector attracted the notice of Prof. Goodsir and Sir William Turner, who was then Senior Demonstrator in Anatomy. ‘This led to his appointment as one of the Demonstrators in that department. At Goodsir’s suggestion he studied the asymmetry of the flat fishes, and chose this subject for his medical thesis, for which he was awarded a gold medal. In 1866, he became Professor of Natural History in the Royal Agricultural College, Cirencester ; in 1867, Professor of Zoology in the Royal College of Science, Dublin; and in 1873, he was appointed Keeper of the Natural History Collections in the Museum of Science & Art, Edinburgh—a post which he held until his retirement in 190G. The last of these appointments gave him exceptional facilities for pursuing the study of ichthyology, which he had chosen as his special line of research. He acquired for the Museum a magnificent series of fossil fishes, chiefly from the Old ied Sandstone and Carboniferous rocks of Scotland. The methods adopted by him while investigating these organic remains revo- lutionized this branch of enquiry. His work was ‘essentially based on morphological structure, and not on the mere outline of the body nor on the configuration of scales and teeth. Throughout his long and active career he published nume- rous papers, chiefly on fossil fishes, which have appeared in the Monographs of the Paleontographical Society, the Transactions of the Royal Society of Edinburgh, and the Proceedings of the Royal Society. His researches were of especial significance to the zoologist, by reason of the light thrown, in some conspicuous instances, on the question of evolution. Thus, early in his career, he showed that the Palsoniscidee were more closely allied to the recent sturgeon than to the existing Lepidosteus, with which they had previously been compared. He further pointed out that the Platysomidee were a specialized offshoot from the Paloniscide. The new fish-fauna, discovered by the officers of the Geological , Vol. 69.] ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixv Survey in the Silurian rocks of the South of Scotland, led him to the conclusion that the Ccelolepide, though not actual sharks, had probably a common origin with the primitive Elasmobranchs. He also showed that the armour-plates of the genera Psammosteus, Drepanaspis, Pteraspis, and Cephalaspis had been formed by the fusion of the Ceelolepid scales one with the other and with hard tissue developed in a deeper layer of the skin. To Scottish geologists his services were of the highest value, on account of their bearing on the stratigraphy of the Old Red Sand- stone and Carboniferous formations. He hada thorough knowledge of the vertical range and distribution of the fossil fishes contained in these two systems in Scotland. By means of the fishes he arranged the Carboniferous rocks in two great divisions, drawing the boundary-line about the horizon of the Millstone Grit. Fol- lowing the classification of Murchison and Salter, he regarded the Orcadian rocks as of Middle Old Red Sandstone age, and pointed out the existence of three fish faunas in that division in Caithness. Advancing further, he called attention to the occurrence of three fish faunas in the Upper Old Red Sandstone on the south side of the Moray Firth, the highest of which (Rosebrae) yielded an assem- blage similar to that found at Dura Den. The artistic restorations of fossil fishes with which he enriched his memoirs are worthy of special mention. They have been fre- quently reproduced in geological publications. Traquair was elected a Fellow of the Geological Society of London in 1874, and of the Royal Society in 1881. In 1878 and 1901 respectively the Royal Society of Edinburgh awarded to him the Neill and the Macdougall-Brisbane Medals; in 1901 the Geological Society awarded to him its Lyell Medal, and in 1907 he received from the Royal Society one of its Royal Medals. In 1893 he received the honorary degree of LL.D. from the University of Edinburgh. He died on November 22nd, 1912. rea (eaiiae ete R. Bruce Foore, who died on December 29th, 1912, joined the Geological Survey of India in September 1858, and retired in September 1891. His service was almost entirely spent in the Madras Presidency, where he examined and described, in conjunc- tion with Dr. W. King, the Kadapah and Karnul Systems; our knowledge of the Upper Gondwana and the Cretaceous of the eastern coust is very largely due to his labours, as also the recognition and separation of the Dharwar System. Though VOL, LXIX. é Ixvi PROCEEDINGS OF THE GEOLOGICAL socrery. [March 1913, belonging to the older school of geology, and though all his work on the Archean rocks was done before the introduction of modern methods of petrographical research, he recognized the importance of the results of their application; and it must be placed to his credit that, without their aid, he succeeded in establishing the division of the Archzean rocks into two entirely distinct systems, a division which has been found to hold good in all other regions where an extensive area of Archean rocks is exposed and has been studied with care. After leaving the Survey he entered the service of the Baroda State for a time, and afterwards that of the Mysore Government, where he organized a State geological service. Besides his purely geo- logical work he was one of the earliest discoverers, and later a most enthusiastic investigator of relics of ancient man in Southern India ; he formed an extensive collection of stone-implements, which is now deposited in the Madras Museum, and was for long recog- nized as a leading authority on this branch of research, which formed the subject dealt with in a paper published in vol. xxiv of the Quarterly Journal of this Society. He was elected a Fellow of the Geological Society in 1867. [R. D. O.] By the death of Captain ArrHur Wir1iam Srirre on August 14th, 1912, we lose one of the regular attendants at our meetings. Stiffe was mainly educated at the Stuttgart Polytechnic, where he gained a silver medal for higher mathematics. In February 1849, being in his 18th year, he entered the navy of the East India Company as midshipman. He was lieutenant of the steam-frigate Ajdaha during the Persian war of 1856-57, and was present at the capture of both Bushire and Muhamra, receiving a medal for his services. He was then employed in making hydrographic surveys of the Persian Gulf and other areas for the Indian Government. When on ieave in England after the Persian war he studied engineering under James Abernethy, and was subsequently appointed Engineer-in-Chief of the cables laid in the Persian Gulf by the Government of India. On the abolition of the Indian Navy in 1857, he was appointed to the Royal Indian Marine, and served in it until he retired with the rank of Commander in April, 1388. In December 1873, a paper by Stiffe on the ‘ Mud-Craters & Geological Structure of the Mekran (Baluchistan) Coast’ was com- municated by Ramsay to this Society, and in 1874 he became one of our Fellows. Other communications by him will be found in the. Quarterly Journals for 1884 and 1890. Vol. 69.] ANNIVERSARY ADDRESS OF THE PRESIDENT. lxvil In 1879 Stiffe was appointed Port Officer at Calcutta, and in 1890 he was Engineer-in-Chief of the Halifax-Bermuda cable, which he successfully laid. He was the author of sailing directions for the Persian Gulf and other seas, and was a Younger Brother of the Trinity House. Stiffe joined the Geologists’ Association in 1894, and served on the Council of that Association from 1902 to 1908, during a part of which time he was Vice-President. During his latter years he was accustomed to spend some weeks in the summer in Norway. Returning home at the end of July, apparently in good health, he celebrated his Slst birthday with his family at Goring. Two days afterwards, on Wednesday, August 14th, 1912, the end came suddenly. Captain Stiffe married in 1863 Henrietta, daughter of John Stone, J.P., D.L. for Buckinghamshire, and they had two sons and a daughter. He was a man of great energy and of a most genial disposition, and will be much missed by his large circle of friends (EEL Wie] among geologists. JosEPpH DickINson was born on November 24th, 1818, at Neweastle-on-Tyne. He received his early education at Dr. Bruce’s school in that town, but in 1833 became a pupil of Mr. Thomas Sopwith, F.R.S., a mining and civil engineer of eminence. During the spring terms of 1839-40 he conducted the preliminary classes of Sir Charles Lemon’s Experimental Mining School at the Royal Institution, Truro. In 1840 he entered on active service at the Dowlais Ironworks and Mines, and in 1842 set out the first railway-sidings at the Bute Docks, Cardiff. Leaving Dowlais in ' 1847, he spent three years at the Nithsdale Ironworks, Scotland, where he laid out railways and opened mines. In 1850, the first Act of Parliament for the Inspection of Mines in Great Britain haying been passed, Joseph Dickinson was one of the four inspectors then appointed, and was placed in charge of Lancashire, Cheshire, North Wales, Staffordshire, Shropshire, and Worcestershire. For +1 years Mr. Dickinson well served his country. He was engaged on numerous Government enquiries and missions, and in 1866 was appointed a member of the Royal Coal Commission, of which he was the sole survivor when the Royal Commission on Coal-Supplies reported in 1905. On December 31st, 1891, at the age of 73, he resigned his post as Inspector of Mines, but till the day of his death maintained an active interest in the practical applications of > © 62 Ixvill PROCEEDINGS OF THE GHOLOGICAL society. [March 1913, geology. He was elected a member of the Manchester Geological & Mining Society in 1856, and was President in 1861, 1877, and 1887. Retaining his faculties unimpaired to the last, he attended constantly and spoke frequently at the meetings. Among the numerous papers contributed by him, his section of the Coal Measures of Lancashire, and his reports on the rock-salt and brine-deposits of Cheshire are of high value. He was elected to the Geological Society of London in 1842, and at the time of his death was ‘father’ of our Society. He con- tributed a paper on the ‘ Jackstones’ of Merthyr Tydvil in 1846, but during most of the 70 years of his Fellowship his interests were chiefly centred in Manchester scientific circles, He died on April 27th, 1912, at the age of 93. [J. G.] [For the information on which the following notice is founded I am indebted to the ‘ Geological Magazine’ for 1912, p. 525. | Rogert Asnineron Burien died on August 14th, 1912. Born in 1850 at St. George’s, Bermuda, he came to England at the age ot 6, and was educated at Gosport, eventually taking a B.A. degree in London University. In 1875 he was ordained, and after spending some years in teaching, became Vicar of Shoreham (Kent). Here he was thrown into close companionship with Prestwich, and was. inspired to commence investigations on the superficial deposits of the: Chalk Downs. Latterly he had devoted himself more especially to a study of the land and fresh-water mollusca which are associated with early human remains, and to the implements of flint and bone identified with Paleolithic and Neolithic man. His work on non-marine mollusca was of a high order, and his papers on the ceolian deposits of the coast at Etel ; on fossil mollusca from Alcudia (Mallorca) and on Manresa (Cataluia); and on the geology of his. birth-place, the Bermudas, especially merit attention. He was elected into the Geological Society in 1891, and was a member of several other Societies. Few but his most intimate. friends can have realized how much kindness and liberality were concealed by his natural modesty and dread of ostentation. Jamns Parker, best known as an antiquary, was born in 1833, and died on October 10th, 1912. He was educated at Winchester, and received an honorary degree of M.A. at Oxford in 1877. His activities in archeological research are manifested chiefly in the Proceedings of the Oxford Architectural & Historical Society, but he was publisher also of the ‘Karly History of Oxford,’ of the y Vol. 69.] ANNIVERSARY ADDRESS OF THE PRESIDENT. lxix ‘ A.B.C. of Gothic Architecture,’ and of the ‘ Introduction to Gothic Architecture.’ In geology he did much useful work in the neigh- bourhood of Oxford, collecting fossils from the Oolitic rocks, and among them some saurian remains which are described in Phillips’s ‘Geology of Oxford.’ He had assisted also in the exploration of eaves in Somerset. He was elected a Fellow of the Geological Society in 1867. Joun Mortson, who died on April Ist, 1912, was a distinguished medical man. After passing through Guy’s and University College Hospitals, he took the degree of M.D. at Edinburgh University in 1865, and in the same year became a member of the Royal College of Surgeons of Kngiand. While holding many medical posts, including that of Medical Officer of Health of St. Albans, he found time to contribute several papers to the Hertford- shire Natural History Society, and to occupy the presidential chair of that society in the years 1905-1907. His attention was drawn chiefly to the outcrops of Chalk and especially of the Chalk Rock in the neighbourhood, and in the course of years he had collected a large number of fossils, which he presented to the Hertfordshire County Museum. He was elected a Fellow of the Geological Society in 1887. Wiriiam Henry Pickerineé was born on October Ist, 1858, and was educated at St. Peter’s School, York. In 1881 he obtained his certificate as a colliery-manager, and in 1883 was appointed an Inspector of Mines, serving as_ assistant-inspector in South Staffordshire, as chief inspector in the Yorkshire & Lincolnshire District, and eventually as divisional inspector for the Yorkshire & North Midland Division. In 1904, having been lent by the Imperial Government to the Government of India for three years as inspector of mines, he continued the work begun by Mr. James Grundy, the first inspector of mines in India, and introduced into practice the Indian Mines Act of 1901. Mr. Pickering was prominent in the establishment of the Mining & Geological Institute of India, acting as the first secretary. At the time of his death he was President of the Indian Mining & Geological Club, London, of which he was the founder. After his return he held office in yarious mining and engineering societies, and was the author of several papers on mining questions. In 1910 he was awarded, an Edward Medal of the first class for gallantry in Ibe PROCEEDINGS OF THE GEOLOGICAL socrnry. [March 1913, attempting the rescue of a miner after an accident in a Yorkshire colliery. On July Sth, 1912, while heroically leading a party at Cadeby Colliery in the hope of effecting rescues after an explosion of firedamp, with full knowledge that the danger was imminent, he lost bis life through the gas exploding a second time. Sir Cuartes Wartenean, J.P. and D.L.Kent, was born in 1834. He was elected to the Geological Society as long ago as 1872, but devoted himself chiefly to the study of agriculture in all its branches. On this subject he became a well-known authority, and served on the Loyal Commission on Agriculture in 1893-97. He received the honour of knighthood in 1907, He died on November 29th, 1912. Joun Samvet Puen died on March 11th, 1912, in his ninetieth year. He served as Master of the Clothworkers’ Company in 1906-1907, and was a Vice-President of the Royal Society of Literature. He was elected into the Geological Society in 1886, and for several years served on the Council of the Palzeontographical ‘Society. He was perhaps best known as the designer of a house in Oakley Street, Chelsea, which he intended to represent the Chateau Savigny in Central France, where his Huguenot ancestors lived. Mucw attention has been devoted of late years to the form and structure of the Paleozoic platform upon which the Secondary rocks of England rest. The interest in it has been centred chiefly upon the possible existence of profitable coal- fields, but we must remember that it is to the search for these that we are indebted for the means of pursuing other investigations which may not be financially important, but are of much scientific interest. ; The configuration of the platform came up for consideration about six years ago, when some pendulum-experiments on variations in gravity were being made at Greenwich and Kew by Col. Burrard, preliminary to transporting the apparatus to India for the continu- ance of observations in that country. I then collected such data as were available, and prepared a map showing a contour-lne drawn upon the surface of the platform at 1000 feet below sea-level. The map was published in 1908 (Survey of India, Professional Paper, No. 10), but since that date so much fresh evidence has so _ come to hand as to render possible considerable additions to the conclusions then drawn. 4 Vol. 69. ] ANNIVERSARY ADDRESS OF THE PRESIDENT. Txeny Upon the map thus revised (Pl. A, facing p. Ixxviii) all noteworthy borings are shewn, so far as regards Central and Southern England. Upwards of forty of them, made in search either of coal or water, have been carried down to the Paleozoic platform, and against each is placed the depth in feet below sea-level at which the platform was met. Against the others, which failed to reach the platform, the depth attained is indicated, but is distinguished by a difference in type and by being placed in parentheses with the symbol +. Though the borings are scattered with some abundance over parts of the area illustrated, the platform remains unknown in two regions. You will notice that it has not been reached anywhere south of a line drawn through Brabourne, Slough, end Burford, though some of the borings have attained a depth of nearly 2000 feet. Further, it may be pointed out that no attempt has been made to reach it in a broad tract extending from the estuary of the Thames north-westwards between Ware and Weeley. Contour-lines drawn at intervals of 500 feet upon the surface of the platform have been inserted, wherever there is sufficient evidence of their position. Thus a contour-line at 1000 feet below sea-level (indicated on Pl. A as —1000) can be drawn with fair precision through Kent and to the south and east of London, though its position in the intervening area is not known. This same contour-line also separates Weeley, Harwich, and Lowestoft on the one hand, from Stutton and Culford on the other. A second contour-line drawn at 500 feet below sea-level can be located on the sides of a valley in the platform northwards from Rugby, and can be followed thence along a meandering course with a general south-easterly trend between Calvert and Wytham, where it turns north-eastwards past Ware, The evidence does not suffice for the insertion of any lines between Ware and Culford; but the fact that at Saffron Walden between these two places Oolitic rocks exist, although they are absent on either side, proves that the area has been one of depression in Oolitic times, and is not unlikely to be one of low elevationnow. Lastly, a contour-line could be drawn with considerable precision at sea-level; but it suffices for my purpose to show the areas in which the Paleozoic rocks emerge from beneath the Secondary rocks into the open air. On these areas contour-lines at 500 and 1000 feet above sea-level could easily be added, though they would indicate, not the original features of the platform, but those which it has acquired through denudation since it was exposed to the air, which is not part of my present subject. Ixxil PROCEEDINGS OF THE GEOLOGICAL socipry. [| March 1913, It will be seen from this map (PI. A, facing p. Ixxylii) that in two regions the platform is known to attain a depth of more than 1500 feet below sea-level, namely in the south and towards the north-east. Between the two it forms comparatively high ground, with a general trend to the south-east, as shown both by the —500 and the — 1000 foot contour-lines. No connexion, however, between its features and its geological structure appears, so far as our limited knowledge of the latter enables usto judge. For example, Cambrian and Silurian strata enter into the composition of the highest parts of the platform at Calvert, and into the lowest part at Harwich and Lowestoft ; while the Coal Measures in Kent torm higher ground than do the highly inclined older Paleozoic rocks anywhere near them. Nor does the form of the platform give any obvious clue to the strike of the rocks that compose it. This character is not in accordance with what is observable in a Paleozoic area which has been exposed to subaérial denudation. In such a case, however complete the original planation has been, the effect of erosion has been to develop features dependent upon the relative resistance offered by the rock-masses. As a rule, though not invariably, the Coal Measures survive only in basins. In seeking an explanation of its form we remember in the first place that the greater part of the platform has never been exposed to subaérial waste since it was planed by marine agencies. It has suffered denudation in various parts at various epochs. Much of it was trenched in Triassic, or planed down in Jurassic times ; some of it contributed débris to Lower Cretaceous formations, while not a little was levelled in Upper Cretaceous times before it was overspread by the Gault. But, in every case except the first-mentioned, it was immediately overspread by marine sediments,and has remained so covered ever since. There has, consequently, been no opportunity for the development of the characteristic sculpturing of subaérial denudation. A still more important cause, however, is to be sought in the warping which the platform has undergone since its last planation. That the faults and folds which are observable in the Secondary rocks would be recognizable in the platform 1s not probable ; they are, on the contrary, essentially surface-phenomena, and may be regarded as the efforts of a skin to adapt itself to changes in form of an underlying body. But that there has been tilting and warping of the platform is certain, and that it has been intermittent and oscillatory is capable of proof as for example in the case of the 4 Vol. 69.1 ANNIVERSARY ADDRESS OF THE PRESIDENT. ]xxiil Wealden Anticline, which has been shown by Mr. Lamplugh to have been superimposed upon a syncline. In fact, owing to the swelling out of the Lower Cretaceous and Upper Oolitic rocks under the arch, the anticlinal structure disappears downwards, and is replaced in the Kimmeridge Clay by a gentle synclinal structure : a relic, doubtless, of a more pronounced syncline which has been flattened by the post-Oligocene movement.’ The coincidence may not be so strange as appears at first sight, for it is not infrequently found that liability to movement, whether upward or downward, is more or less confined to certain tracts. We can hardly suppose, however, that the later warping has generally been so arranged as to counteract precisely the effects of earlier movements. In the limited time at my disposal it is impossible to discuss the effects of all the movements which have affected the platform since its planation, and I propose to confine my remarks to the latest and most energetic, those, namely, that came into operation between Oligocene and Pliocene times, and were demonstrably responsible for the geological structure of the South and Kast of Kngland. For the purposes of this investigation I have selected a single plane in the Upper Cretaceous rocks, which has once been horizontal or approximately so, and have endeavoured to ascertain the magnitude of the distortions that it has undergone. The base of the Gault appeared, after some consideration, to be the most suitable plane for the purpose. It is recognizable over a wider area and with more certainty than any other, while by choosing it I eliminated all the disturbances which had tilted the Lower Cretaceous and Jurassic previously to the deposition of the Upper Cretaceous rocks. It is true that the lowest beds of the Gault are not always present, and that the assumption that the plane was ever precisely horizontal and continuous would be unsound; but the departure from the horizontal is likely to have been trifling in comparison with the figures with which we are concerned, and insufficient materially to affect the conclusions. In the base of the Gault, therefore, I have determined the altitude of as many points as possible, and from these data have constructed a map (Pl. B, facing p. Ixxvili) showing contours at intervals of 500 feet, relative to the present sea-level. The data on which the contours have been drawn haye been derived from several sources. In the first place, the altitude of the base along visible outcrops was determined at frequent intervals. * ‘Mesozoic Rocks of Kent’ Mem. Geol. Surv. 1911, p. 94. lxxiyv PROCEEDINGS OF THE GEOLOGICAL sociEty, [March 1913, This, combined with a number of well-sections near the outcrop, rendered possible the tracing of the line along which the base of the Gault les at sea-level, that is the contour-line marked 0 on the map. Next, the deep borings in which the base of the Gault has been identified provided a series of points of precision. There were also available a large number of well-sections which, without reaching the base of the Gault, gave the level of the base of the Chalk or in other ways provided materials for an estimate. Lastly, when all other evidence failed, I used the numerous well-sections which have proved the level of the top of the Chalk under Tertiary beds, and estimated the thickness of the Upper Cretaceous rocks from a consideration of the nearest deep boreholes or measured sections. These last estimates are open to the objection that the Tertiary beds cut across the Chalk, in places markedly so. In the western and north-western parts of the area this method could only be used with caution. For the most part, however, the results obtained were so consistent that my confidence in them was somewhat restored. Altogether seven contour-lines, ranging from 500 feet above the sea (shown on the map as +500) to 2500 feet below the sea (shown as —2500) have been traced. Of these the + 500 line is evidenced in a few places only, where a neighbouring outcrop either attains or closely approximates to that height, as at Leighton Buzzard, near Bletchley, in the Vale of Wardour, north-west of Penshurst, in the Weald, in the Isle of Wight, and in Dorset and Devon. The —1000 line has been drawn, so far as regards the London Basin and the ground north of it, mainly by reference to deep borings. All lines below —1000 are confined to the Hamp- shire Basin. They have been drawn by reference to the level of the top of the Chalk as found in borings, and by consideration of the thickness of the Upper Cretaceous rocks as developed in the nearest outcrops. The map thus constructed gives a comprehensive view of the various flexures under consideration. It illustrates, in the first place the increase in intensity and frequency of the folding towards the south, and shows how in each syncline the axis hugs the southern margin. You may notice, for example, the broad spacing of the 0, —500, and —1000 lines on the northern side of the London Basin, and the comparative crowding of the same lines on the southern side. The two sides of the Hampshire Basin not only show the same difference, but the greater depth of the syncline as compared with that of the London Basin is well brought out. wv Vol. 69.] ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixxv It becomes apparent also, that neither the major anticlines nor synclines are simple in structure; they are made up of subsidiary folds which, though individually discontinuous, maintain effective continuity. Thus the London Basin includes two hollows, the one under the estuary of the Thames, the other west-south-west of London, close under the steep uplift of the Hog’s Back. Subsidiary folds occur in the Wealden Anticline, both in the area from which the Chalk has been denuded and in that where the arch is more perfect. The overlapping and replacing anticlines in the Isles of Wight and Purbeck are readily recognized. There are other points which I am tempted to mention, though briefly, for they scarcely form part of my present subject. It will be noticed that in the Chalk escarpment which extends across Hngland from Lincolnshire to Dorset there are some rather abrupt changes in strike, all of which produce an anticlinal structure. Between Lincolnshire and Norfolk (beyond the northern margin of Pl. B) the strike changes from N. 30° W. to north and south; near Culford it changes to W.35°8.; near Goring it changes from H.30° N. on the north side of the Thames to east and west in the White Horse Hills on the south side of the river; farther south it is interrupted by the Pewsey and Wardour Anticlines. In every case a breach has been effected in the escarpment, and a line of drainage traverses it in the direction of general dip. In the Wealden area a notable change of strike occurs near the centre of the northern scarp at Maidstone, and here the ridge is traversed by the Medway. Iam not aware that any of the other breaches in the North and South Downs coincide with changes of strike, but the coincidence in the cases which I have mentioned is sufficiently frequent to be significant. The subject deserves further investigation. Again, the map gives a comprehensive view of the general tilt whieh turned the drainage of England eastwards, and of the par- ticular lines of syncline and anticline which determined the courses taken by the rivers. At the south coast our evidence ceases, but the increasing intensity of these determining folds southwards invites the speculation that the primary cause of the separation of England from the Continent was the establishment of a west-to- cast line of drainage analogous to those of the Thames and the Frome, and the subsequent invasion of that line by the sea. It must be remembered, however, that the English Channel does not follow the east-and-west structures consistently, but that it cuts across the Wealden Anticline in the Straits of Dover. Ixxv1 PROCEEDINGS OF THE GEOLOGICAL society. [March 1913. The objects, however, which I had more especially in mind in preparing this map were an illustration of the magnitude of the post-Oligocene movements, and of their effect upon the platform. The deepest hollow, as I have already mentioned, occurs in the Hiampshire Basin, where the base of the Gault is estimated to lie more than 2500 feet below Ordnance datum. In the London Basin the greatest depth attained may amount to 1500 feet, in a small area 4 or 5 miles north of the Hog’s Back. A depth of 1419 feet was proved in a deep boring close by. Between the two basins rises the anticline of the Weald. The ground in the Wealden area reaches an elevation of 803 feet above the sea at its highest point. I assume that the aggregate thickness of the part of the Wealden formation and the Lower Greensand which has been removed by denudation must have exceeded 700 feet, and that the elevation of the base of the Gault in the crown of the arch may be safely put at not less than 1500 feet. It follows that the difference in level in the base of the Gault caused by the post- Oligocene movements is not less than 3000 feet as between the Wealden Anticline and the London Basin, and not less than 4000 feet as between that anticline and the Hampshire Basin. These are large figures, and in face of them we are compelled to assume that the platform cannot have escaped warping through the post- Oligocene movements, even though it may have stood firm against the more trivial folding and faulting suffered by the Secondary rocks. Having now gained some conceptien of the magnitude of the latest movements, we may endeavour to ascertain what the form of the platform would be if those effects were eliminated: in other words, to ascertain what its form was at the commencement of Upper Cretaceous time. For this purpose we combine the two maps (Pls. A & B), and by their aid correct the elevation or depression undergone at every known point on the platform. Pl. B shows what correction is necessary at any spot to bring the base of the Gault to horizontality at present sea-level. The same correction made in the depth to the platform at the corresponding points on Pl. A will restore those points to the rela- tive levels which they held when the Gault was deposited. Thus all the points where the Gault rests directly upon the platform will be indicated by the figure 0. At the Richmond boring, where the base of the Gault lies at 1122 feet below Ordnance datum, the ’ Vol. 69. | ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixxyit depth to the platform must be diminished by that amount, and will be indicated by —98 instead of —1220 feet ; while in the Calvert ‘and Bletchley borings, where the Gault no longer exists, but where its base is estimated to have been 700 feet above sea-level, the respective depths to the platform must be increased by that amount, and become —853 and —859 feet instead of —153 and —159 feet. The map forming Pl. C shows the result of applying this correction to every point within, or close to, the area occupied by the Gault, at which the platform has been proved. It therefore reproduces the form which the platform would possess if the base of the Gault were a true plane at sea-level. In other words, it eliminates the effects of the post-Oligocene movements. On comparing Pl. C with Pl. A we are able to realize that the form of the platform was much altered by those movements. In the central portion of the map a tract of high elevation clearly defines itself under London, and reappears north-eastwards near Harwich. The contouring between Harwich and Lowestoft now ranges north-north-eastwards along the slopes of that tract, instead of northwards. The ridge apparently proved by the Calvert and. Bletchley borings is no longer in evidence. Those places now appear as being situated on the north-western slopes of the elevated tract ; nor is there any reason to doubt that the same slope extends south- westwards towards Burford, where I have inserted an estimate of —1300 to — 1600 feet, on the supposition that the base of the Gault, if it still existed, would be between 500 and 800 feet above the sea. Thus the existence of a ridge in the Paleozoic platform is not in itself sufficient to prove the continuation of an ancient axis, such as that of Charnwood. On the other hand, the fact that Cambrian rocks constitute the platform at Calvert, and the probability that Charnian rocks were reached at Bletchley are highly significant of an old line of upheaval. On the south side of the elevated tract the features of the platform increase in boldness. The upland ends in a great declivity which is well-defined from Dover past Penshurst, and has a gradient of upwards of 1 in 26. That its descent continues to a depth of more than 4000 feet is proved at Penshurst, but how much farther it may go is not known. Assuming, however, that 1500 feet is not an exaggerated estimate for the elevation of the base of the Gault in the crown of the Wealden arch, and taking this in connexion with the Ixxvili PROCEEDINGS OF THE GEOLOGICAL socinry. [ March 1913, results of the Sub- Wealden boring, we are justified in supposing that the declivity shown by the —1000 and 1500-foot contours on the map represents the marginal part only of a prolonged slope. It is significant that the only boring which has reached the Paleozoic platform below the declivity shows the existence of Trias; at Brabourne 81 feet of marls and conglomerates lay unconformably on the steeply tilted Palaeozoic rocks. It seems, therefore, that that formation circles round the elevated tract on its southern, as well as on its western and northern sides. From this fact and from the development cf the Jurassic rocks, it appears that the sag in the Paleozoic platform had been in progress more or less all through Mesozoic times, and that the superimposing of the Wealden Anticline upon it has been a minor incident upon the margin of the sagging area, not materially changing its character as a dominant factor in the structure of Southern England. It isremarkable, too, that the London syncline has been superimposed upon what had been for long a tract of. elevation. One of the results of the elimination of the post-Oligocene move- ments has been to accentuate the importance of the elevated tract of Eastern Hngland at the expense of the Paleozoic areas of Western England and Wales: for, of course, the general tilt of the Upper Cretaceous rocks towards the west has been eliminated, as well as the synclines and anticlines. The evidence on which the relative levels of the London area and the western areas could have been estimated has perished with the denudation of the Upper Cretaceous rocks; but, if it 1s right to suppose that those rocks extended continuously over the western areas, we are confronted with a distribution of Paleozoic tracts in pre-Gault times which differs widely from the distribution now in existence. At any rate, the existence of the elevated tract in early Cretaceous times explains several points that were obscure. It provides a probable source for some Palzeozoic material which enters largely into the composition of some of the Lower Cretaceous rocks, and has clearly not travelled far. It explains also the attenuation of the Jurassic rocks and the littoral character assumed by them in its neighbourhood, On the other hand, it must be admitted that there still is no obyious connexion between the configuration and the structure of the platform. Though little has been done as yet towards tracing the outcrops of the rocks which compese the Paleozoic platform, we CONTOUR-LIN a © Gr @ ° SOOO ee ee IR Ce eceaeee® 9 (937+) eieteluiaiy ls ae Slough © io40¢ Winkfield | ® Brookwo (744 +) Chichester ®@ (1009+) 51° To face p. Ixxviii.] Quart. Journ. Geol. Soc. Vol. LXTX, Pl. A. MAP OF BORINGS, SHOWING CONTOUR-LINES ON THE PALZOZOIC PLATFORM. ° I {eo} o (842+) Norwich * (1191+) Lowestoft e) 615 Burford 834 ° Swindon ° (407+) ° Wytham. (413+) © Brookwood (744+) Penshurst Luchley @ Pi (17604). (1613 +) : ‘brabonr Chichester 2° (1009+) Battle 21605 Telscombe 885+) 52 sI° ee ee ~ ya ee eee @ eas ae Ad Pane MG dipeky desire ah bet bali vii rey rte inertia ne Nee To face p. Lxxviii.] Quart. Journ, Geol. Soc, Vol. LXIX, Pl. B. MAP SHOWING CONTOUR-LINES JN THE BASE OF THE GAULT., 2° is} o Burford ° Ewindon © © 2322 |. of rEWwen Wytham chee os =o a 22> e-10168 Winkfield B rookwood Frogs Bak e —22¢e@ )-97) +1530 (t57*) Lowestoft, =1574' OY te tee Liane arene =e EEN om anny) DA neni ay dara nena Zappa sie Teor hid f Ane: BM ERT ET OE pe PEO pa wren E mah SI Raining smh ee one St ee Sen “b> 7 # y #2 e, tn e~ . ‘ . Kn 1 — ~~ j 7 wed ne - rs : ’ \ as 4 \ ; = ¢ Li; = i “4 \ To face p. 1xxviii.] Quart. Journ, Geol. Soc. Vol. LXIX, Pl. C. MAP SHOWING THE CONTOUR-LINES OF THE PALZOZOIC PLATFORM CORRECTED FOR POST-CRETACEOUS MOVEMENTS. 2° e ° if in T Lowestoft ° { | (3) or eCulford| _.. 32 ao / 52 ° ee =a Harwich Ware Turnford e Loughton. (-4000)+ (-1800)+ 2 gee es sis ile nana tatet ; 8 ‘ i Sor odtig Leow pe ae +33 : i : : =i ane ad - Ks a fm = ad 2 . 5 3 %2 x = 5 ey Wah SfnSklndainn ee Te eA roe 3 Se ee at Mien! veel. Ey ie ; h we 8 attr Wales an gh ” ARS A he Re pe Se i Rayan age Os gr Ch crn Vol. 69.] ANNIVERSARY ADDRESS OF THE PRESIDENT. lxxix know enough to be certain that there is little, if any, agreement between them and the contouring. The character of the platform seems to be attributable in the first place to marine planation and its form to subsequent warping. For further pursuance of this method of investigation of the platform we must await the gathering of more evidence. So far as regards boring operations, no additional stimulus appears to be called for, so long as there remains a possibility of discovering workable coal, But I find here an opportunity of giving expression to an opinion which I have long held, that registration of deep borings in a Government Department should be made compulsory. In the Final Report of the Royal Commission on Coal-Supplies we inserted the following clause :— ‘ A large number of borings have been made in various parts of the country ranging to upwards of 3000 feet in depth. At present no machinery exists for preserving any information thus obtained, and we think it would be of great advantage if particulars of borings could be collected and preserved in a Government Office.’ This recommendation contemplates the inclusion of scientific results among the other particulars to be preserved, and on this account it might not be acceptable to explorers who for financial reasons were desirous of keeping to themselves the information which they had been put to expense to gain. ‘There would pro- bably be no difficulty in meeting the wishes of the explorers on this point; but, at any rate, the objection would not apply to the registration of other particulars. At present it is open to any member of the community, after agreement with the owner of the land, to bore a hole wherever he likes, as large as he pleases, as deep as he can go, and to leave no record. ‘There can be no object in keeping the site, the diameter, or the depth of the hole secret ; in fact it is not possible to do so. These particulars at least should be compulsorily registered, and the site of an important boring per- manently marked. In one case at least a record, effective so far as it goes, has been made of the exact site, with other particulars, of a borehole. The site of a trial for coal at Foryd, near Rhyl, is marked by an inscribed stone, erected, I believe, by the Office of Woods & Forests. | It may be thought that a sufficient record is kept by the Geological Survey. As a fact, it is only through courtesy or by chance that we learn that borings are in progress. There are many DEX PROCEEDINGS OF THE GEOLOGICAL society. [March 1913, persons who feel strongly the desirability of records being preserved, and make a point of informing us when boring operations are undertaken ; but it happens too frequently that we hear of a bore- hole having been made, too late for an adequate examination of the cores. Others we never hear of, nor are the cores submitted to any competent geologist; and in such cases records, if preserved at all, are apt to be worse than useless. Any hard rock is liable to be called granite; Lower Paleozoic shales, if they are black, become Coal Measures; all red rocks are New Red Sandstone. This is not the time for suggesting the exact form of the machinery which should be created for the preservation of boring records, but I take the opportunity of expressing to you my opinion that our methods of exploration are at present happy-go-lucky and unworthy of our great mineral heritage. There are, however, other lines of investigation to which I wish to direct attention as offering a prospect of throwing more light upon the nature of the complicated mass of Palseozoic rocks which lies under our feet. As geologists, we learn with pleasure from the last Report of Progress of the Ordnance Survey that a revised levelling of the British Isles is in progress. In the primary levelling, which was carried out in the years 1841 to 1859, the precision is not of a modern standard. The levels, moreover, were recorded by rough marks on various objects which were often not permanent. The new levelling has been planned with the object of determining relative altitudes with the utmost attainable precision, and of recording levels by permanent marks which are founded on rock below the subsoil, and are, so far as can be foreseen, free from suspicion of shifting from any cause whatever apart from movement of the earth’s crust. Various difficulties, to which I need not now refer, arose in the selection of suitable sites for these ‘ fundamental points’; but in the levelling, when carried out with such precision as is contemplated, certain factors of unknown value may have to be taken into account. Among these I may mention the existence of earth-tides, and also the effect of the oceanic tide in temporarily depressing the coast upon which it impinges. But what I have in my mind more especially is the variation in gravity which is known to exist, but has never been syste- matically investigated in the British Isles. A large number of ob- servations on the deflection of the plumb-line and on the varying Vol. 69.] ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixxxl rate of the pendulum, both due to variations in gravity, have been and are being made in various parts of the world, notably in Austria, Germany, America, and India. In India it has been stated that gravity is greater on islands than on the coast of the mainland, greater on the coast than inland, and greater on the plains than in the immediate neighbourhood of the Himalayas. Col. Burrard, by recent observations with the plumb-line, has shown that a line of high density crosses India in lat. 23° N., and that between this and the Himalayas exists a line of low density, or, as he terms it, a ‘deep rift,’ in the approach to which the change in the amount of deflection is remarkably rapid. The effects of the rift are so great as to obliterate the effects of topography and isostasy. So far as regards the immense alluvial plains of Northern India the plumb- line is deflected everywhere away from the mountains, and the deflections are in opposition both to the topography and the theory of isostasy. The observations in Great Britain were carried so far as to indicate the existence of variations in gravity which were not to be explained by the configuration of the ground. Capt. A. R. Clarke, writing in 1858 on discrepancies in latitude when geodetically compared, concludes that ‘it must be assumed that every latitude is affected by two distinct sources of - disturbance: namely, superincumbent irregularly-disposed masses, and irregu- lavities in the distribution of matter below the surface.’ ! In the Isle of Wight he notices a southward deflection, whereas, from the mass of England to the north a northward deflection might have been anticipated (op. cit. p. 712): an interesting ob- servation when taken in connexion with what is now known of the deflection on coast-lines. At Lough Foyle, Ben Hutig, and Edinburgh he found reason to infer ‘ that the plumb-line is drawn southward by dense subterranean masses, At Blackdown in Dorset, Southampton, Greenwich, and in the Shetland Islands deflections were noticed which could not be accounted for by inequalities of the ground. At Portsoy, on the northern coast of Banffshire, there is a local but remarkably large disturbance of eravity which has not been explained. The famous experiments on Schiehallion in 1772, and on Arthur’s Seat in 1855, were made with the view of ascertaining to what 1 «Account of the Observations & Calculations of the Principal Triangu- lation, &o.’ 1858, p. 706. VOL, LXIX. Hi Ixxxli PROCEEDINGS OF THE GEOLOGICAL society. [March 1913, extent the plumb-line is deflected by the attraction of a prominent rock-mass. It appears that such experiments would be of little value, unless they were accompanied by observations on the varia- tions in gravity in the surrounding region where such variations may exist; although the configuration of the ground gives no reason to suspect them. I have quoted these observations made so many years ago, in order to show that the early observers realized the nature of the problems on which they were touching. How far their conclusions would be confirmed or modified by more precise modern methods I do not know; but, taken in connexion with what is being discovered in other parts of the world, the observations serve to prove that, so far as regards the British Isles, the investigations ceased at a critical stage. That there were variations in gravity was proved, and it was recognized that some other cause than inequalities of. the surface must be looked for; but the extent and distribution of the disturbances have not been ascertained. A Gravity Survey seems clearly to be called for. if such a survey were made, a comparison of the results with those of the various magnetic surveys of Great Britain and Ireland would be likely to yield much interest. The last of the magnetic surveys was carried out by Sir Arthur W. Riicker and Sir T. Edward Thorpe. In the reports published in the ‘ Philosophical Transactions’ for 1890 and 1896 a map was presented, showing the relation between the magnetic and the geological features of the United Kingdom. In the words of the authors ‘the magnetic indications appear to be quite independent of the disposition of the newer strata,’ but it must also be admitted that their con- nexion with the form and geological structure of the Paleozoic platform, so far as these are known, is not obvious. On the other hand, instances are reported in Germany of coincidence between magnetic ridge-lines and lines of equal gravity that can hardly be accidental. I may here remind you that, at the last meeting of the British Association a recommendation was made in Section A to the effect, ‘that it is desirable that a detailed Magnetic Survey of the British Isles, on the lines of Professors Riicker and Thorpe for the epoch of 1891, should now be repeated, in order to answer the question as to the local variations of the terrestrial magnetic elements within 25 years.’ T should regard a Gravity Survey as at least equally desirable. Vol. 69.] ANNIVERSARY ADDRESS 01’ THE PRESIDENT. Ixxxill In these brief remarks on a wide subject I have been able to mention only a few of the investigations on gravity which have been made. My object has been to show that in the best-mapped country in the world a great work remains tobe done. The plat- form which we have had under consideration not only presents undulations, but is composed of a variety of rocks varying in specitic gravity, for it includes ancient sediments, some lying hori- zontally, some highly inclined, in parts cleaved, with metamorphic and igneous masses in places. Having regard also to the insular character of Great Britain and its situation upon the margin of the European Continent, we seem to be confronted with a region in which a Gravity Survey is pre-eminently desirable. 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[March 1913. February 26th, 1913. Dr. Ausrey Srrawan, F.R.S., President, in the Chair. Arthur Blakeney Coussmaker, c/o Johnson, Matthey & Co., 78 Hatton Garden, E.C.; Gordon Downes, B.Sc., Roseneath, Bromley Road, West Bridgford (Nottinghamshire) ; John Spencer, Assoc.M.Inst.M.E., 212 Blackburn Road, Accrington; and Frank Charles Thompson, B.Se., Demonstrator in Geology in the Uni- versity of Sheffield, 79 Wilkinson Street, Shetfield, were elected Fellows of the Society. The List of Donations to the Library was read. The following communications were read :— 1. ‘The Geology of Bardsey Island (Carnarvonshire).’ By Charles Alfred Matley, D.Sc., F.G.S. ; with an Appendix on the Petrography by John Smith Flett, M.A., D.Sc., F.G.S. 2. ‘The Loch Awe Syncline (Argyllshire) By Edward Battersby Bailey, B.A., F.G.S. Rock-specimens from Bardsey Island were exhibited by Dr. C. A. Matley, F.G.S., and Dr. J. 8. Flett, M.A., F.G.S., in illustration of _ their paper. March 5th, 19138. Dr. AusRey Srranan, F.R.S., President, in the Chair. Herbert Crompton Rawsthorne, Assov.M.Inst.C.E., Dunscar Fold, Bromley Cross (Lancashire), was elected a Fellow of the Society. The List of Donations to the Library was read. The following communications were read :— ieee hers Kelloway Rock” of Scarborough.’ By 8.8. Buckman, F.G.S. Ub, 2. «On Jurassic Ammonites from Jebel Zaghuan (Tunis).’ By Leonard Frank Spath, B.Sc., F.G.S. The following specimens and photographs were exhibited :— Specimens and photographs, exhibited by 8. 8. Buckman, F.G.S., in illustration of his paper. Specimens of Jurassic ammonites from Tunis, exhibited by L. F. Spath, B.Sc., F.G.S., in illustration of his paper. Vol. 69. | PROCEEDINGS OF THE GEOLOGICAL SOCIETY. x¢clil March 19th, 1913. Dr. Ausprey Srranan, F.R.S., President, in the Chair. George Knox, Lecturer on Geology & Mining in the Wigan Mining College, 14 Swinley Road, Wigan; Gaston Félix Joseph Preumont, The Avenue, Bishop’s Waltham (Hampshire) ;, and Ernest R. Spragg, 134 The Avenue, Highams Park, Chingford (lissex), were elected Fellows of the Society. The List of Donations to the Library was read. The Prestpenr announced that the Council had awarded the Proceeds of the Daniel Pidgeon Fund for the present year to RopErick Unrwick Saycn, B.A., University College of Wales, Aberystwyth, who proposes to investigate the rock-succession and structure of the Ystwyth Valley and its neighbourhood. The following communications were read :-— 1. ‘The Geology of Northern Peru: Tertiary and Quaternary Beds.’ By Beeby Thompson, F.G.S8., F.C.S. 2. ‘The Internal Cranial Elements and Foramina of Dapedius granulatus, from a Specimen recently found in the Lias at Char- mouth.’ By George Allan Frost, F.G.S. The following specimens, etc. were exhibited :— Specimens, photographs, and lantern-slides exhibited by Beeby Thompson, F.G.S., F.C.S., in illustration of his paper. Skull of Dapedius granulatus, exhibited by G. Allan Frost, F.G.S., in illustration of his paper. Manuscript geological map of Southern Rhodesia, exhibited by F, P. Mennell, F.G.S. April 9th, 1913. Dr. Auprey Srranay, F.R.S., President, in the Chair. The List of Donations to the Library was read. A letter was read from Prof. F. D. Apams, President of the 12th International Geological Congress, expressing the hope that Fellows of the Society and British geologists in general would be largely represented at the Congress, which is to be held in Canada VOL. LXIX. h XC1V PROCEEDINGS OF THE GEOLOGICAL society. [June 1913, next August. He added that every endeavour is being used to make the Congress a success, and that excursions have been arranged to almost every accessible part of the Dominion. The following communications were read :-— 1o) 1. ‘The Variation of Planorbis multiformis Broun.’ By George Hickling, D.Sc., F.G.S., Lecturer in Palzeontology & Demonstrator in Geology in the Victoria University of Manchester. 2. ‘The Structure and Relationships of the Carhonicole.’ By Miss M. Colley March, M.Sc. (Communicated by Dr. G. Hickling, HEGeS)) Lantern-slides were exhibited by Dr. G. Hickling, F.G.S., in illustration of his paper. A Special General Meeting was held at 7.45 p... (before the Ordinary Meeting), at which (1) the retirement on pension of the Assistant-Librarian, Mr. William Rupert Jones, was sanctioned ; and (2) the appointment as Assistant-Clerk of Mr. Maurice St. John Hope was confirmed. April 23rd, 1913. Dr. Auprey Srranan, F.R.S., President, in the Chair. Thomas Dewhurst, Assoc.R.C.S., 151 Rectory Road, Burnley (Lancashire); George Sheppard, Lecturer in Geology at the Hull Technical College, Sunny Bank, Withernsea (Yorkshire) ; Alfred Leo Simon, Ph.D., Arundel, The Park, Sidcup (Kent) ; Herbert Edward Taylor, 51 Mysore load, Lavender Hill; Bat- tersea, S.W.; David Thomas, c/o the Institution of Mining & Metallurgy, Salisbury House, E.C.; and Douglas Graeme Williams, Downderry, Crawstone Road South, Westcliff-on-Sea (Essex), were elected Fellows of the Society. Prof. Dr. Emile Haug, Paris, and Dr. Per Johan Holmquist, Stockholm, were elected Foreign Correspondents of the Society. The List of Donations to the Library was read. Prof. E. Hurt described the large chart of the North Atlantic Ocean which was hung on the wall. his chart had been prepared to illustrate the paper which he had read at the Meeting of the International Zoological Congress held at Monaco in March, to show the mode of migration of animals by land-connexion between Europe and the American Continent, due to the great uplift of the Vol. 69. | PROCEEDINGS OF THE GEOLOGICAL SOCIETY. XCV whole region by several thousands of feet during the Mio-Pleistocene Epoch. ‘The chart showed at a glance the submerged structure of the ocean-bed and bordering coasts on both sides of the Atlantic, indicating a rise of 1000 to 1200 fathoms (6000 to 7200 feet) during the culminating stage of the Glacial Pericd. This was proved by the fact that the channels of the existing rivers—such as the Loire, the Adour, the Mondego, the Tagus, and the Congo— were continued down to the depths above named, across ‘ the Con- tinental Platform’ and ‘the Great Declivity’ to the floor of the Abyssal Ocean. The details had been worked out by means of the soundings taken from the Admiralty charts and the isobathic contours, the details of which are recorded, with the charts apper- taining thereto, in the speaker’s ‘Monograph of the Sub-Oceanic Physiography of the North Atlantic Ocean.’ In the view of the speaker this great uplift of the Northern Hemisphere was the vera causa of the Glacial Period or ‘ The Great Ice-Age’ of Prof, James Geikie. The following communications were read :— oO 1. ‘On the Fossil Flora of the Pembrokeshire Portion of the South Wales Coalfield” By Reginald H. Goode, B.A. (Communi- cated by Dr. EK. A. Newell Arber, M.A., F.G.8.) 2. ‘The Halesowen Sandstone Series of the Southern End of the South Staffordshire Coalfield; and the Petrified Logs of Wood found therein at Witley Colliery, Halesowen (Worcestershire). By Henry Kay, F.G.8S. With an Appendix on the Structure of a New Species of Dadowylon, by EK. A. Newell Arber, M.A., Se.D., To llpeen LAE In addition to the exhibit described on pp. xciv—xevy, the following specimens, maps, ete. were exhibited :— Specimens and lantern-slides of Carboniferous plants from Pembrokeshire, exhibited in illustration of the paper by KR. H. Goode, B.A. Petrified logs of wood, etc. from the South Staffordshire Coalfield ; also photographs, microscope-sections, and lantern-slides, exhibited by Henry Kay, F.G.S8., in illustration of his paper. Geological Survey of England & Wales: 1-inch Geological Map (n. s.) Sheet 349—lvybridge (colour-printed), 1913. Presented by the Director of H.M. Geological Survey. Geological Survey of Scotland: 1-inch Geological Map, Sheet 64 —Kingussie (colour-printed), 1913. Presented by the Director of H.M. Geological Survey. Geological Map of Victoria: 1 inch=16 miles, 1912. Presented by the Director of the Geological Survey of that State. Imperial Geological Survey of Japan: 1: 200,000 Geological Map—Ichinohe, Kanazawa, Kiso, and Shichinohe, 1912. Presented by the Director of that Survey. XCV1 PROCEEDINGS OF THE GEOLOGICAL socinTy. [June 1913, May 7th, 1913. Dr. Ausprey Srrawan, F.R.S., President ; and afterwards W. Waurraker, B.A., F.R.S., F.G.S., in the Chair. The List of Donations to the Library was read. The following communications were read :-— 1. ‘The Bathonian Rocks of the Oxford District.’ By M. Odling, WO ANg IBM, 106ras\ 2. ‘On the Petrology of the Kalgoorlie Goldfield (Western Australia).’ By James Allan Thomson, M.A., D.Sc., F.G.S. Lantern-slides, rock-specimens, and microscope-sections were exhibited by M. Odling, M.A., B.Sc., F.G.S., in illustration of his paper. May 28th, 1913. Dr, Ausrey Srranan, F.R.S., President, in the Chair. Ernest Masson Anderson, H.M. Geological Survey, 43 Ladysmith Road, Edinburgh; John Edward Austin, F.R.A.S., West Court, Detling, near Maidstone; Harvey Collingridge, B.Se., Assoc.M Inst.C.E., Auburn, Denville, Havant; Arthur Francis Hallimond, B.A., Assistant Curator in the Museum of Practical Geology, 28 Jermyn Street, S.W.; John Ranson, Assoc.M.Inst.M.E., 174 Willows Lane, Accrington; Richard Daniel Thomas-Jones, 5 Park View, Broughton, near Manchester ; William Henry Turton, M.B., C.M., Barlborough House, Heanor (Derbyshire); and George H. Uttley, M.A., M.Se., High School, Oamaru (New Zealand), were elected Fellows of the Society. The List of Donations to the Library was read. The Pruesipenr, in referring to the loss which the Society had that day sustained by the decease of Joun Lussoocx, Ist Baron AverBury, recalled the fact that Lord Avebury had been a Fellow of the Society for no less than fifty-eight years, that he had con- tributed several valuable papers to the Society’s Journal, and that he was the recipient of the first Prestwich Medal. The President added that he felt sure that the Fellows would associate themselves with the resolution of condolence and sympathy which the Council had addressed to Lady Avebury. Vol. 69.] PROCEEDINGS OF THE GHOLOGICAL SOCIETY. x¢cvil The following communications were read :—— 1. ‘On the Age of the Suffolk Valleys; with Notes on the Buried Channels of Drift.’ By Percy G. H. Boswell, B.Sc., F.G.S. 2. ‘The Internal Structure of Upper Silurian Rugose Corals from the Grindrod Collection, Oxford Museum.’ By Donald Esme Innes, b.A. (Communicated by Prof. W. J. Sollas, Sc.D., F.R.S., F.G.S.) The following specimens were exhibited :— Examples of water-rolled flints, and a typical specimen of chalky silt, exhibited by P. G. H. Boswell, B.Sc., F.G.S., in illustration of his paper. Specimens of Upper Silurian corals, with microscopic sections, exhibited in illustration of the paper by D. E. Innes, B.A. Slab with numerous specimens of Microdiscus punctatus, from the Solva Beds, east side of Solva Harbour, accompanied by a photographic enlargement, exhibited by W. P. D. Stebbing, F.GS. Sponges from the Upper Chalk of Grays (Essex); also Ostrea with marks of attachment to the inner whorls of an ammonite, and Heogyra with colour-bands, from the Lower Chalk of Burham (Kent), exhibited by G. E. Dibley, F.G.S. June I1th, 1913. Dr. Auprey Srrawan, F.R.S., President ; and afterwards W. Waurraxker, B.A., F.R.S., in the Chair. The List of Donations to the Library was read. The Names of certain Fellows of the Society were read out for the first time, in conformity with the Bye-Laws, Sect. VI, Art. 5, in consequence of the Non-Payment of the Arrears of their Contributions. The following communications were read :— 1. ‘Certain Upper Jurassic Strata of England.’ By Dr. Hans Salfeld, University of Géttingen. (Communicated by S. S. Buckman, F.G.S.) 2. ‘The Voleanic Rocks of the Forfarshire Coast and their Associated Sediments.’ By Albert Jowett, M.Sc., F.G.S. 3. ‘On a Group of Metamorphosed Sediments situated between Machakos and Lake Magadi in British East Africa. By John Parkinson, M.A., F.G.S. XeVH1 PROCEEDINGS OF THE GEOLOGICAL socizry. [June 1913, The following photographs and specimens were exhibited :— Photographs and specimens of Upper Jurassic ammonites, ex- hibited by S. 5S. Buckman, F.G.S., in illustration of Dr. Salfeld’s paper. - Hand-specimens and rock-sections, exhibited by A. Jowett, M.Sc., F.G.S., in illustratien of his paper. Rock-specimens from British Kast Africa; exhibited by J. Parkin- son, M.A., F.G.S., in illustration of his paper. June 25th, 1913. Dr. Auprey Srraaan, F.R.S., President, in the Chair. Frederick Hughes, 16 Park Crescent, Merthyr Tydfil; Irvine George Jardine, B.Sc., 82 Matthews Park Avenue, Stratford, E. ; Frederick Henry Loury-Corry, B.A., Edwardstone Hall, Boxford (Suffolk); James Alec Mitchell, 46 Warwick Road, Ealing, W.; W. J. Reynolds, 19 St. Clair Avenue, Port of Spain (Trinidad); the Rev. W. J. Ryan, §.J., University of Innsbruck (Tyrol); Prof. Stephen Taber, Ph.D., Columbia (South Carolina), U.S.A. 5 Principal William Thomas, M.Inst.M.E., Glanffrwd, Cemetery Road, Porth (Glamorgan); ard William Robert Watt, M.A., B.Sc., Schoolhouse, Knocklands (Morayshire), were elected Fellows of the Society. The List of Donations to the Library was read. The Names of certain Fellows of the Society were read out for the second time, in conformity with the Bye Laws, Sect. VI, Art. 5, in consequence of the Non-Payment of the Arrears of their Contributions. Mr. C. Dawson, F.S.A., F.G.S., exhibited zinc-blende occurring in ironstone nodules which contain plant-remains, in the celebrated plant-bed of the Fairlight Clays, Fairlight, near Hastings. He remarked that the form is crystalline and the ore is frequently found filling up cavities left by the decayed vegetable matter. Zinc-blende is not known to occur at other horizons in the Weald, nor anywhere else in the South-East of England. It is probably segregated from older rocks of which the Wealden strata are composed. He also exhibited pisolitic limonite, which occurs in con- siderable quantities at one or two horizons in the Fairlight Clays, near Hastings. On the shore at Pett Level, near Fairlight Cliff-end, Vol. 69.] PROCENDINGS OF THE GEOLOGICAL SOCIETY. XCiX a very large deposit is found, just above the ordinary high-water mark. The deposit consists of minute spberical grains or nodules of sand-like character. These, on being analysed, prove to contain 60 per cent. of iron-oxide. In the cliff the iron-ore occurs in bands, the grains of which it is composed forming a compact grey conglomerate which turns dark brown on exposure. Many pieces of the conglomerate are to be found on the shore in a rolled condition. When disintegrated, they are deposited by the joint action of the eastward drift of the tide and the south-westerly wind along the shore. The deposit last year measured about half a mile in jength, by about 30 or 40 yards in width, and was 3 to 4 feet deep. The following communication was read :— ‘The Miocene Beds of the Victoria Nyanza and the Geology of the Country between the Lake and the Kisii Highlands.’ By Felix Oswald, D.Sc., B.A., F.G.S.; with Appendices on the Verte- brate Remains, by Charles William Andrews, D.Se., F.R.S.; on the Non-Marine Mollusca, by Richard Bullen Newton, F.G.S.; and on the Plant-Remains, by Miss Bancroft. In addition to the exhibits described on pp. xeviii-xcix, Lower Miocene mammalia and gasteropoda from the Victoria Nyanza, and rocks and stone-implements from the Nyanza Province, also Pleistocene mammalia from British East Africa, were exhibited in illastration of Dr. Felix Oswald’s paper. On Wednesday, June 18th, 1913, a Conversazione, at which about three hundred ladies and gentlemen were present, was held in the Society’s Apartments, from 9 to 11.30 p.w. In the course of the evening, lectures, illustrated by lantern-slides, were delivered by Prof. W. W. Watts, F.R.S., on ‘The Buried Landscape of Charnwood Forest,’ and by Capt. H. G. Lyons, F.R.S., on ‘The Marshes of the Upper Nile.’ Many interesting exhibits were shown by Dr ky. Broom, Mr. G. M. Davies, Mr. G. KH. Dibley, Dr. J. W: Evans, Mr. W. F. Gwinnell, the Rev. H. N. Hutchinson, Dr. J. S. Owens, Mr. J. Postlethwaite, Mr. T. W. Reader, Mr. W. P. D. Stebbing, Dr. Marie C. Stopes, Mr. Bristow J. Tully, Dr. A. Wade, Mr. T. H. Withers, Mr. W. Wright, and the Director of H.M. Geo- logical Survey. ADMISSION AND PRIVILEGES OF FELLOWS OF THE GEOLOGICAL SOCIETY OF LONDON. Every Candidate for admission as a Fellow must be proposed by three or more Fellows, who must sign a Certificate in his favour. The Proposer whose name stands first upon the Certificate must have a personal knowledge of the Candidate. Fellows on election pay an Admission Fee of Six Guineas. The Annual Contribu- tion paid by Fellows is Two Guineas, due on the 1st of January in every year, and payable in advance; but Fellows elected in November or December pay no Contribu- tion for the current year. The Annual Contribution may, at any time, be compounded for by a payment of Thirty-Five Pounds. The Fellows are entitled to receive gratuitously all the volumes or parts of volumes of the Quarterly Journal of the Society that may be published after their election, so long as their Annual Contributions are paid; and they may purchase any of the publications of the Society. at a reduction of 25 per cent. under the selling-prices. The Library is open daily to the Fellows between the hours of 10 and 5 (except during the fortnight commencing on the first Monday in September; see also next page), and on Meeting-Days until 8 p.m. Under certain restrictions, Fellows are allowed to- borrow books from the Library. Publications to be had of the Geological Society, ' Burlington House. QUARTERLY JOURNAL. (Vols. III to LXIX, inclusive.) Price to Fellows, 13s. 6d. each (Vols. XV, XXIII, XXX, and XXXIV to LXIX, 16s. 6d.), in cloth. GENERAL INDEX TO THE FIRST FIFTY VOLUMES OF THE QUARTERLY JOURNAL (1845-1894). Part I (A-La). Part IL (La-Z). Price 5s. each. To Fellows 3s. 9d. each. [Postage 3d.] GEOLOGICAL LITERATURE added to the Geological Society’s Library during the years ended December 31st, 1894-1911. Price 2s.each. To Fellows, 1s. 6d. each. [Postage 3d. ] THE HISTORY OF THE GEOLOGICAL SOCIETY OF LONDON, by H. B. Woopwarp, F.R.S. Price 7s. 6d. To Fellows, 6s. [Postage 6d.] THE CENTENARY OF THE GEOLOGICAL SOCIETY OF LONDON, recorded by W. W. Warts, F.R.S. Price 2s. net. [Postage 3d.] . HUTTON’S ‘THEORY OF THE EARTH,’ Vol. III, edited by Sir ARCHIBALD GEIKIE, D.C.L., F.R.S. Price 3s. 6d. To Fellows, 2s. [Postage 4d.] THE GEHOLOGY OF NEW ZEALAND. Translated by Dr. C. F. Fiscuer from the works of MM. HocustrrterR & PETERMANN. With an Atlas of Six Maps. Fellows may purchase one Copy of this Book at 2s. Additional Copies will be charged 4s. [Postage 5d. ] CONTENTS, PAPERS READ. Page 24. Mr. J. Parkinson on a Group of Metamorphosed Sediments between Machakos and Lake Magadi (Plate LI) ............ccccccceccecccuceuceesnsneens 534 25. Mr. L. F. Spath on Jurassic Ammonites from Jebel Zaghuan (Plates LIT OPIS) Mere cole ataNalcuie te ela ee eatin oda is ecra GRR e ea ae Ee ao CREE eee 540 26. Mr. P. G. H. Boswell on the Age of the Suffolk Valleys and the Buried Channelsiof Dritt (Plates TalVed AiV)e sce ee eee ncee, eee 581 27. Dr. J. A. Thomson on the Petrology of the Kalgoorlie Goldfield ............ 621 TITLE-PaGEe, CONTENTS, AND INDEX TO VoL. LXIX. [No. 277 of the Quarterly Journal will be published next March. | {The Editor of the Quarterly Journal is directed to make it known to the Public that the Authors alone are responsible for the facts and opinions contained in their respective Papers. | *,* The Council request that all communications intended for publication by the Society shall be clearly and legibly written on one side of the paper only, with proper references, and in all respects in fit condition for being at once placed in the Printer’s hands. Unless this is done, it will be in the discretion of the Officers to return the communication to the Author for revision. Tke Library at the Apartments of the Society is open every Weekday from Ten o’clock until Five, except during the fortnight commencing on the first Monday in September, when the Library is closed for the purpose of cleaning; the Library is also closed on Saturdays at One p.m. during the months of August and September. itis open until Hight p.m. on the Days of Meeting for the loan of books, and from Hight p.m. until the close of each Meeting for conversational purposes only. |Z | a4 2 oe a ? = ad os es EN rs ey yi asic WO 3 9088 8 01350 214