tas nonfemteete ee eiecttvsinetpetseie ani pent JOURNAL AND PROCEEDINGS OF THE ROYAL SOCIETY NEW SOUTH WALES FOR 1911. (INCORPORATED 1881.) NM OF 2a Vi. EDITED BY THE HONORARY SECRETARIES. PHB ADVFHORS OF PAPERS ABE ALONE RESPONSIBLE FOR THE STATEMENTS. MADE AND THE OPINIONS EXPRESSED THEREIN. SYDNEY : PUBLISHED BY THE SOCIETY, 5 ELIZABETH STREET NORTH, SYDNEY. LONDON AGENTS : GEORGE REOBERTSON & Co., PROPRIETARY LIMITED, 17 Warwick Square, ParernosTzE Row, Lompon, B.C, 1912. 216 8&1 es EeEEn me? 1 ay bi © = ——) oD So =: “NOTICE. - Tue Roya Socrery of New South Wales originated in 1821 as the ‘‘ Philosophical Society of Australasia”; after an interval of inactivity, it was resuscitated in 1850, under the name of the ** Australian Philosophical Society,” by which title it was known until 1856, when the name was changed to the ‘ Philosophical Society of New South Wales”; in 1866, by the sanction of Her Most Gracious Majesty Queen Victoria, it assumed its present title, and was incorporated by Act of the Parliament of New South Wales in 1881. * TO AUTHORS. Authors of papers desiring illustrations, are advised to consult the editors (Honorary Secretaries) before preparing their drawings. Unless otherwise specially permitted, such drawings should be carefully executed to a large scale on smooth white Bristol board in intensely black Indian ink, so as to admit of the blocks being prepared directly therefrom, in a form suitable for photographic “process.” The size of a full page plate in the Journal is 4} in. x 62in. The cost ofall original drawings, and of colouring plates must be borne by Authors. ERRATUM. Page 59, line 2, for ‘‘ predominance of peripheral over radial contraction etc.,” read “ predominance of radial over peripheral contraction ete.” obtained at the Society’s House in Elizabeth-street:— Transactions of the Philosophical Society, N.S. W., 1862-5, pp. 374, out of print. 1. Transactions of the Royal] Society, N.S. W., 1867, pp. 83, II. Vol. The following publications of the Society, if in print, can be XXI. XXII. XXIII. XXIV. XXV. XXXVI. XXVII. XXVIII, XXIX. XXX. XXXI. XXXII. XXXIII. XXXIV. KXXV. XXXVI. XXXVII. XXXVIII. XXXIX. XL. XLI. XLII. XLII. XLIV. XLV. PUBLICATIONS. ——— 1868, ,, 120, 1869, ,, 173, 1870, ,, 106, 1871-:,, 72: 1872, ,, 123, 1873, ,, 182, 1874, ,, 116, 1875, ,, 235, 1876, ,, 333, 1877, ,, 305, 1878, ,, 324, price 10s.6d.. 1879, ,, 255, 1880, ,, 391, 1881, ,, 440, 1882, ,, 327, 1883, ,, 324, 1884, ,, 224, 1885, ,, 240, 1886, ,, 396, 1887, ,, 296, 1888, ,, 390. 1889, ,, 534, 1890, ,, 290, 1891, ,, 348, 1892, ,, 426, 1893, om) 530, 1894, ,, 368, 1895, ,, 600, 1896, ,, 568, 1897, ” 626, 1898, ,, 476, 1899, ,, 400, 1900, ,, 484, 1901, ,, 581, 1902, ,, 531, 1903, ,, 663, 1904, ,, 604, 1905, ,, 274, 1906, ,, 368, 1907 ,, 377, 1908, ,, 593, 1909, ,, 466, 1910, ,, 719, 1911 , 611, ” 9 ART ART CONTENTS. VOLUME XLV. . L.—PRESIDENTIAL ADDRESS. By T. W. EpcreworrH Davin, C.M.G., B.A., F.R.S., Hon. D.Sc. Oxon. [With Plates I - ITI.] . II.—Notes on Transition Curves. By WaLTER SHELLSHEAR, M. Inst. C.E,, Art. III.—Observations on the Corrosion of Steel in Water. By ART. ART. ART. ART. ART. ART. ArT. ART. G. J. Burrows, B.sc., and C. E. Fawsirt, p.se. (Contribu- tion from the Chemical Department, University of Sydney). [With Plate IV.] IV.—Studies in Statistical Representation: Statistical applications of Fourier Series. Illustrated by the analysis of the rates of marriage, temperature, suicide, etc.) By G. H. KNIBBsS, ¢.M.G., F.RA.S., F.S.S. etc. Commonwealth Statistician... V.—Echinorhynchus pomatostomi, (n.s.), a subcutaneous para- site of Australian Birds. By T. Harvey JOHNSTON, M.A, D.sc., and J. BuRTON CLELAND, ™.D., Ch.M., (From the Government Bureau of Microbiology, Sydney, N.S.W.) VI.—Erosion and its Significance. By E. C. ANDREWS, B.A., Department of Mines, Sydney. ... VII.—Notes on the Geology of West Moreton, Queensland. By R. A. WEARNE, B.a., and W G. WoOoLNOUGH, D.sc,, F.G.S. VIIl.—Preliminary note on the Geology of the Kempsey District. By W. G. Woo.noveH, psc, F.G.s., Lecturer in Applied Geology and Mineralogy, University. [ With PlateV. ] IX.—The Effect of Heating and Antiseptic Treatment on the Solubility of Fertilising Ingredients in Soils. By H. I. JENSEN, D.sc., Chemist’s Branch, The Department of Agri- culure of New South Wales. X.—Preliminary note on the Nepheline-bearing Rocks of the Liverpooland Mount Royal Ranges. By W.N. Benson, Bsc. [With Plates VI, VII.] Susi Sante ne ae XI.—On the Occurrence of Explosive or Booming Noises (Barisal Guns) in Central Australia. By J. Burton CLELAND, M.D. Pace. 1 61 67 76 111 116 137 159 169 176 187 ART. ART. ART. ART. ART. ART, ART. ART. ART. ART. ART. ART, ART. (viii.) XII.—The Origin of the Small Bubbles of Froth. By J. A. Pouuock, v.sc, Professor of Physics in the University of Sydney. [With Plates VIII, IX, X.] XILI.—Suicide in Australia: A Statistical Analysis of the Facts. By G. H. Knripss, ¢.M.G., F.R.A.8., F.S.S., etc., Com- monwealth Statistician, ... XIV.—Note on a new type of aperture in Conularia. By Cnuas. F. Laszron. [With Plate XI.]... XV.—The River Gravels between Penrith and Windsor. By H. I. JENSEN, D.Sc. ... See aes eee ain ie pe XVI.—An Autographic Air-Flow Recorder. By W. R. HEBBLEWHITE, B.E. (Communicated by Prof. 8. H. Barra- clough, B.E., M.m.E.) [With Plate XII.] XVII.--On some New England Eucalypts and their Economics. By R. T. Baxer, F.u.s., and H. G. Sm1ru, F.c.s., Technological Museum, Sydney. [With Plate XIII.]... XVIII.—On Rock Specimens from Central and Western _ Australia, collected by the Elder Scientific Exploring Expe- dition of 1891-2. By J. Auuan THOMSON, B.A., D.Sc, F.G.8. (Communicated by Prof. David, B.a., c.M.G., F.R.S., Hon. pD.se. Oxon.) [With Plate XIV.]... XIX.—A suggested explanation of Allotropism based on the Theory of Directive Valency. By F. B. Guthrie, F.1.c., Department of Agriculture. ee ate 7 ee XX.—The nature and origin of Gilgai Country; with notes on Quaternary Climate. By H. I. JEnsgEn, D.sc. XXI.—Some Curious Stones used by the Aborigines. By R. H. Matuews, ts. [With Plate XV.] XXII.—On the Australian Melaleucas and their Essential Oils. By Ricoargp T. Baker, F.L.s., and Henry G. SmitH, F.c.s., Technological Museum, Sydney. [With Plates XVI - XXIV. | ae inp ane ie ne na XXIII.—The Geology of the Eruptive and Associated Rocks of Pokolbin, New South Wales. By W. R. Browns, B.se., and A. B. WaLkom, B.sc, Demonstrators in Geology, Uni- versity of Sydney. [With Plates XXV -XXVIII.] ... XXIV.—The value of the Nitrate Figure in determining the fitness of Water for Drinking Purposes. By C.S. Wits, M.D.,M.B.C8. [With Plate XXIX.] ... PaGe 204, 225 247 249 258 267 292 318 337 359 365 379 408 (ix.) PAGE ArT. XXV.—Haematozoa of Australian Birds, No. 2. By J. Burton CLELAND, M.D., ch.m., Government Bureau of Micro- biology, Sydney. N.S.W., and T. Harvey JOHNSTON, M.A., p.se, Queensland University, Brisbane. [With Plates XXX - MEMITT.) . «0. a ae ae ne ah ae a. SLD Art. XXVI.—The Geology and Petrography of the Prospect Intrusion. By H. STanugy JEVONS, M.A., B.Sc., F.G.8., H. I. JENSEN, D.Sc, T. GRIFFITH TAYLOR, B.A., B.Se, and C, A. SussMILcH, ¥F.G.s. [With Plates XXXIV —XL.] as wee 4465 Art. XXVII.—Note on the occurrence of Teniopteris in the roof of the coal seam in the Sydney Harbour Colliery. By W.S. Dun. [With Plate XLI.]... By ms ies sot | ODA: ABSTRACT OF PROCEEDINGS by sit ash eas i’ i, — xix. PROCEEDINGS OF THE GEOLOGICAL SECTION ... aes ioe. UX RY, TitLe Paces, Notices, PUBLICATIONS, CONTENTS, ... we, (li=" Vale) OFFICERS FOR 1911-1912... ase sae ais ted ve Be O.08) List or Mempers, &. ... A it ye oe a ... (xiii.) INDEX To VoLUME XLV. hs aie Ae oa, a7 ... XXVi. DATES OF PUBLICATION. i’ $ VotumMeE XLV. ‘Part I—pp. 1-64, published October 24,1911. Ti— ,, 65-224, ,, February 8, 1912. { a ; , ITI— ,, 295-444, ,, June 26, 1912) nn , IV— ,, 445-555, ,, September 30,1912, L" land par 5 Vis & Ah ated’ ‘a , rea AMopal Docietp of Aew South Bales. OPP EPEC ens Om 2olt-19O12. Patron: HIS EXCELLENCY THE RIGHT HONOURABLE THE EARL OF DUDLEY, P.c., G.c.M.G., @.C,V.0. Governor-General of the Commonwealth of Australia. Vice~Patron: HIS EXCELLENCY THE RIGHT HONOURABLE LORD CHELMSFORD, x.c.m.a. Governor of the State of New South Wales. President: J. H. MAIDEN, F.1.s. Vice-Presidents: W. M. HAMLET, F.1.c., F.c.s. F. H. QUAIFE, m.a., M.D. H. D. WALSH, B.A.1.,M. Inst.C.E, | Prof.T.W.E. DAVID, c.m.e., B.A.,DSe Hon. Treasurer: D. CARMENT, t.1.4., P.F.A. Hon. Secretaries: F. B. GUTHRIE, F.1.¢.,¥.c.s. | Prof. POLLOCK, psc. Members of Council: R. H. CAMBAGE, L.s., F.LS. CHARLES HEDLEY, v.u.s. H. G. CHAPMAN, m.p. T. H. HOUGHTON, M. Inst. oO. J. B. CLELAND, ™.p., ch.M. HENRY G. SMITH, F.c.s. HENRY DEANE. w.a., M. Inst. .5,| Prof. WARREN, M. Inst.C.E., Wh.Sc. R. GREIG-SMITH, p.sc. W. G. WOOLNOUGH, D.Se., F.G.S. FORM OF BEQUEST. £ bequeath the sum of £ to the Roya Society oF New Sourn Watss, Incorporated by Act of the Parliament of New South Wales in 1881, and I declare that the receipt of the Treasurer for the time being of the said Corporation shall be an effectual discharge for the said Bequest, which I direct to be paid within calendar months after my decease, without any reduction whatsoever, whether on account of Legacy Duty thereon or otherwise, out of such part of my estate as may be lawfully applied for that purpose. [ Those persons who feel disposed to benefit the Royal Society of New South Wales by Legacies, are recommended to instruct their Solicitors to adopt the above Form of Bequest. | RES er a ee ee NOTICE. Members are particularly requested to communicate any change of address to the Hon. Secretaries, for which purpose this slip is inserted. Corrected Address: SOS cares OCOD MOOSE HOT HEH EH HTH SES EEO SERRE LEHT IE ORE SOE EEE LCS « vee eee eee tedsee cee eee seRnsesseseseees eee eel eens ASSL) S vy e)(8 (8 8)\viee) (aia)is e/a (8) 616 #8) 8) hiole)© |e 6 eie\e |e als sle)¢ 0/e)¥) tee: seas) a'6 0/06 00/6 66.0.6 00 oie a6 vice ele soucelelese cle de picnckcisitaniclcl neta choker soles) e/®) dsje}iriele {aisiiehe\e\a)leje(eiis}s)ale]eie) ale) ¥\are\(s/ale 6{@\@]0\e\alels'g\elisloleieie/e)leleievele/aie)sie/eieleleve\sleisieverele COC ROO OGD ROOC OT CID SOCIO COO 0000 OO CIROO CODIGCO OOO CDOD COCO OCcUD OU 0 UOC OCOUUU UN CIOOCITOO OOOO OOGOOCOCMECROOIET To the Hon. Secretaries, The Royal Society of N. S. Wales, 5 Elizabeth Street, Sydney. LIST OF THE MEMBERS Aopal Societp of Ae South Wales. P Members who have contributed papers which have been published in the Society’s: Transactions or Journal; papers published in the Transactions of the Philosophical Society are also included. The numerals indicate the number of such contributions. oe Life Members. ected. 1908 Abbott, George Henry, b.a., mB. ch.m.. Macquarie-street ; p.r: ‘Cooringa,’ 252 Liverpool Road, Summer Hill, 1877 | P5| Abbott, W. E., ‘Abbotsford,’ Wingen. 1911 Abbott, John Henry Macartney, St. James’ Chambers. 1895| . | Adams, J. H. M., Broughton Cottage, St. James’ Rd.,Waverley.. 1904| . | Adams, William John, M. 1, Mech. £.. 175 Clarence-street. 1898 Alexander, Frank Lee, c/o Messrs. Goodlet and Smith Ld., Cement Works, Granville. 1905 Anderson, Charles, m.a., D.sc. Hdin., Australian Museum, Col- lege-street. 1909 | P 4; Andrews, E. C., B.a., Geological Surveyor, Department of Mines, Sydney. 1878 Backhouse, Alfred P., m.a., District Court Judge, ‘ Melita,” Elizabeth Bay. 1894 |P 17| Baker, Richard Thomas, Fr.t.s., Curator, Technological Museum.. 1894 {Balsille, George, ‘ Lauderdale,’ N.E. Valley, Dunedin, N.Z. 1896 Barff, H. E., w.a., Registrar, Sydney University. 1908 | P 1) Barling, John, ‘St. Adrians,’ Raglan-street, Mosman. 1895 | P9| Barraclough, S. Henry, 8.n., M.M.E., Assoc. M. Inst, C.E., M.I, Mech. E.,. Memb. Soc. Promotion Eng. Education; Memb. Internat. Assoc. Testing Materials; Lecturer in Mechanical En- gineering, Sydney University; p.r. ‘Marmion,’ Victoria-- street, Lewisham. 1906 Basnett, Nathaniel James, Accountant, Punch-st., Mosman. 1894 Baxter, William Howe, Chief Surveyor, Existing Lines Office, Railway Department, Bridge-street, 1877 Belfield, Algernon H., ‘ Eversleigh,’ Dumaresq. 1900 Bender, Ferdinand, Accountant and Auditor, 21 Elizabeth- street, North. 1909 Benson, William Noel, B. Se. 1905 Bignold, Hugh Baron, Barrister-at-Law, Chambers, Went- worth Court, €4 Elizabeth-street. 1905 Blakemore, George Henry, Australian Club, Macquarie-street. 1888 {Blaxland, Walter, F.R.c.s. Eng., L.R.c.P. Lond., Fremantle, West Australia. 1893 Blomfield, Charles E., 8.c.z. Melb., ‘ Woombi,’ Kangaroo Camp,. Guyra. (xiv.) Elected 1898 Blunno, Michele, Licentiate in Science (Rome), Government Viticultural Expert, Department of Agriculture, Sydney. 1907 Bogenrieder, Charles, Mining and Consulting Engineer, ‘Scibile,’ Little’s Avenue, off Nicholson-street, Balmain. 1879 t{Bond, Albert, 131 Bell’s Chambers, Pitt-street. 1907 Boyd, Robert James, M,£., Assoc. M. Inst. C.e., ‘Greenstead,’ Park Road, Burwood. 1910 Bradley, Clement Henry Burton, M.B., Ch. M., D P.H., Bureau of Microbiology, Macquarie-street. 1876 Brady, Andrew John, L.K.&Q.C.P. Irel., LR.CS. Irel., 3 Lyons Terrace, Hyde Park. 1891 Brennand, Henry J. W., B.a., M.B, Ch.M. Syd., ‘ Wobun,’ 310 Miller-street, North Sydney. 1902 Brereton, Victor Le Gay, Solicitor, Royal Chambers, Hunter- street, p.r. ‘Osgathorpe,’ Gladesville. 1878 ftBrooks, Joseph, F.R.A.S., F.R.G.S., ‘ Hope Bank,’ te street, Woollahra. 1876 Brown, Henry Joseph, Solicitor, Newcastle. 1906 | - Brown, James B., Resident Master, Technical School, Gran- ville; p.r. ‘Kingston,’ Merrylands. 1903 Bruck, Ludwig, Medical Publisher, 15 Castlereagh-street. 1898 {Burfitt, W. Fitzmaurice, B.A., B.Sc., M.B., Ch.M. Syd., 857 Glebe Road, Glebe Point. ‘1890 Burne, Dr. Alfred, Dentist, Buckland Chambers, 183 Liverpool- street. - 1907 |. Burrows, Thomas Edward, ™. mnst.c.z,, us, Metropolitan En- gineer, Public Works Department; p-r. ‘ Balboa,’ Fern- street, Randwick. 1880 | Bush, Thomas James, ™. mst.c.z,, Australian Gasiee Com- pany, 153 Kent-street. 1999 Calvert, Thomas Copley, assoc. M. Inst, 0.E,, ‘ Maybank,’ Manly. 1904 |P1}Cambage, Richard Hind, t.s., F.u.s., Chief Mining Surveyor ; p.r. Park Road, Burwood. 1907 Campbell, Alfred W., Medical Practitioner, 183 Macquarie-st. 1900 Canty, M., ‘ Rosemont,’ 13 York-street, Wynyard Square. 1876 Cape, Alfred J., m.a. Syd., ‘ Karoola,’ Edgecliffe Rd., Kdgecliffe. -1897 | P 4] Cardew, John Haydon, m. mst. c.z., u.s., 75 Pitt-street. 1S01 Card, George William, A.R.s.M., F.a.s., Curator and Mineralogist to the Geological Survey, Department of Mines, Sydney. 1891 Carment, David, F.1.A. Grt. Brit. & Trel., F.F.A, Scot., Australian Mutual Provident Society, 87 Pitt-st. Hon. Treasurer. 1909 Carne, Joseph Edmund,r.a.s., Assistant Government Geologist, Department of Mines, Sydney. 1903 Carslaw, H. S., M.A., D.Sc. Professor of Mathematics, Sydney University, Glebe. 1909 Chapman, H.G., m.p., Assistant Lecturer and Demonstrator in Physiology, Sydney University, Glebe. 1908 Chauleur, Paul, Officier de l’Instruction Publique, Conseiller du Commerce Extérieur de la France; Secrétaire-Trésorier de la Chambre de Commerce frangaise, Bond-street. 1909 |P 10] Cleland, John Burton, M.D. ch.M., Principal Assistant Micro- biologist, Bureau of Microbiology, 93 Macquarie-street. Elected 1907 1896 | P 2 1904 | P 2 1876 1906 1882 1909 1892 |P 1 1886 1905 1875 1890 1876; P3 1910 (xv.) Cobham, Allan Blenman, ‘Garthowen,’ Myahgah Road, Mosman. ; Cook, W. E., m.c.e. Melb., M.inst.c.z, Water and Sewerage Board, North Sydney. Cooksey, Thomas, Pn, D., D.sc,, Lond., ¥..c. Second Government Analyst ; p.r. ‘ Clissold,’ Calypso Avenue, Mosman. Codrington, a ohn Frederick, m.R.c.Ss. Hng., L.R.c.P. Lond., L.B.C.P. Edin., ‘ Roseneath,’ 8 Wallis-street, Woollahra. Colley, David John K., Superintendent, Royal Mint, Sydney. Cornwell, Samuel, J.e., Brunswick Road, Tyagarah. Cotton, Leo Arthur, B.a., B.sc. Assistant Lecturer and Demon- strator in Geology, The University of Sydney. Cowdery, George R., Assoc. m. Inst. c.E., ‘Glencoe,’ Torrington Road, Strathfield. Crago, W. H., m.r.c.s. Hng., u.R.c.P. Lond., 16 College-street, Hyde Park. Dampney, Gerald F., r.1.c., ‘ Doonbah,’ Hunter’s Hill. Dangar, Fred. H., c/o W. E. Deucher, 12 and 14 Loftus-street. Dare, Henry Harvey, m.z., M. Inst. c.z., Public Works Department. Darley, Cecil West, m. mnst.c.e., Australian Club, Svdney. Darnell-Smith, George Percy, B.Sc, F.I.c., F.c.s., Bureau of Microbiology, Macquarie-street. 1886 |P 21] David, T. W. Edgeworth, c.m.¢., B.A., D.Sc, F.B.S., F.G.S., 1909 1892) P 1 1907 1885 | P 3 1894 1875 P12 1880 | 1906 | 1876 | | 1899 | P1 1873 | P2 1908 | iP2 Professor of Geology and Physical Geography, Sydney University, Glebe. Vice-President. Davidson, George Frederick, Tramway Offices, Hunter-street; p.r. 223 Bridge Road, Glebe Point. Davis, Joseph, M. Inst. €.5. Davys, Hubert John, c/o Messrs. Clutterbuck Bros. & Co. Builders’ Exchange, Castlereagh-street , p.r. ‘La Bohéme,’ Marshall-street, Manly. Deane, Henry, M.A. M. Inst.C.E., F.LS., F.R. Met. Soc, F.R.H.S., Com- mercial Bank Chambers, George-street ; p.r. ‘ Blanerne,’ Wybalena Road, Hunter’s Hill. Dick, James Adam, B.A. Syd., M.D., C.M., F.R.C.S. Edin., ‘Catfoss,” Belmore Road, Randwick, Dixon, W. A., F.1.c., F.c.s., 97 Pitt-street. Dixson, hoa Storie, M.B., M.S. Edin., 151 Macquarie-street. Dixson, William, ‘Abergeldie,’ Summer Hill. Docker, Ernest B., m.a. Syd., District Court Judge, ‘ Mostyn,” Billyard Avenue, Elizabeth Bay. Duckworth, A., ¥F.R.n.S., A.M.P. Society, 87 Pitt-street ; p.r. ‘Trentham,’ Woollahra. Du Faur. E., F.R.4.s., ‘ Flowton,’ Turramurra. Dun, Willian Se Palzontologist, Department of Mines. > Epps, William, Secretary, Royal Prince Alfred Hospital, Camperdown, Sydney. Esdaile, Edward William, Optician, 54 Hunter-street. Estens, John Locke, 55 Flinders-street, Sydney. (Xvi.) "Elected 1879 P 4, Etheridge, Robert, Junr., s.p., Curator, Australian Museum ; p.v. ‘Inglewood,’ Colo Vale, N.S.W. 1877 {Fairfax, Edward Ross, 8. M. Herald Office, Hunter-street. 1896 Fairfax, Geoffrey E., S. M. Herald Office, Hunter-street. 1868 Fairfax, Sir James R., Knt., S. M. Herald Office, Hunter-st. 1887 Faithfall, R. L., m.p. New York, u.R.c.p., u.s.4. Lond., 5 Lyons Terrace. 1902 Faithfull, William Percy, Barrister-at-Law, Australian Club. 1910 Farrell, John, Assistant Teacher, Sydney Technical College; p.r. 55 Surry-street, Darlinghurst. 1909 |P1| Fawsitt, Charles Edward, p. sc. ph. p., Professor of Chemistry, Sydney University, Glebe. 1881 Fiaschi, T'hos., m.p., M. ch. Pisa, 149 Macquarie-street. 1888 Fitzhardinge, Grantly Hyde, m.a. Syd., District Court Judge, ‘Ned Hill,’ Beecroft. 1900 {Flashman, James Froude, B.A. B.Sc, M.D., Ch.M., Jersey Road, Burwood. 1879 {Foreman, Joseph, m.z.c.s. Hng., .R.c.P. Hdin., 141 Macquarie-st 1905 Foy, Mark, ‘Eumemering,’ Bellevue Hill, Woollahra. 1904 Fraser, James, M. Inst. c.E., Engineer-in-Chief for Existing Lines, Bridge-street; p.r. ‘Arnprior,’ Neutral Bay. 1907 Freeman, William, ‘ Clodagh,’ Beresford Road, Rose Bay. 1899 French, J. Russell, General Manager, Bank of New South Wales, George-street. 1881 Furber, T. F., F.R.4.s., ‘Sunnyside,’ Stanmore Road, Enmore. 1876. George, W. R., 318 George-street. 1879 Gerard, Francis, ‘ The Grange,’ Monteagle, near Young. 1859 Goodlet, J. H., ‘Canterbury House,’ Ashfield. 1906 Gosche, Vesey Richard, Consul for Nicaragua, 1 Bulletin Place, Pitt-street, City. 1906 | Gosche, W. A. Hamilton, Electrical Engineer, 1 Bulletin Place, | Pitt-street, City. 1897 Gould, Senator, The Hon. Sir Albert John, k.c.m.a.,‘Eynesbury,’ Edgecliffe. ; 1907 Green, W. J., Chairman, Hetton Coal Co., Athenzeum Club. 1899 Greig-Smith, R., p. sc. Edin , M.sc. Dun., Macleay Bacteriologist, Linnean Society’s House, Ithaca Road, Elizabeth Bay. 1899 | P 2| Gummow, Frank M., m.c.z., Corner of Bond and Pitt-streets. 1891 |P 16} Guthrie, Frederick B., F.1.c., F.c.s., Chemist, Department of | Agriculture, 136 George-street, Sydney. 1880 | P 3| Halligan, Gerald H., r.a.s., ‘ Riversleigh, Hunter’s Hill. 1892 Halloran, Henry Ferdinand, L.s., 82 Pitt-street. 1909 Hammond, Walter L., Science Master, Hurlstone Agricultural Continuation School, Hurlstone Avenue, Summer Hill. 1887 | P8| Hamlet, William M., F.1.c., F.c.s., Member of the Society of al Public Analysts; Government Analyst, Health Depart- ment Macquarie-street, North. Vice-President. (avin) flected 1905 |P 1| Harker, George, p.s., 35 Boulevarde, Petersham. 1887 |P 23/{Hargrave, Lawrence, Wunulla Road, Woollahra Point. 1884} P 1} Haswell, William Aitcheson, M.A., D.Sc, F.R.8., Professor of Zoology and Comparative Anatomy, University, Sydney; p.r. ‘Mimihau,’ Woollahra Point. 1900 Hawkins, W. E., Solicitor, 88 Pitt-street. 1891 | P 1} Hedley, Charles, F.u.s., Assistant Curator, Australian Museum, Sydney. 1899 Henderson, J., F.R.E.S., Manager, City Bank of Sydney, Pitt-st. 1884 | P 1| Henson, Joshua B., Assoc. M. Inst.c.E, Hunter District Water Supply and Sewerage Board, Newcastle. 1905 Hill, John Whitmore, Architect, ‘Willamere,’ May’s Hill, Parramatta. : 1876 | P 2| Hirst, George D., F.R.4.s., c/o Messrs. Tucker & Co., 215 Clarence-street. 1896 Hinder, Henry Critchley, m.B., o.m. Syd., 147 ieee ase st. 1892 Hodgson, Charles George, 157 Macquarie-street. 1901 Holt, Thomas S., ‘Amalfia, Appian Way, Burwood. 1905 Hooper, George, Assistant Superintendent, Sydney Technical College; p.r. ‘Branksome,’ Henson-street, Summer Hill. 1891 | P 2| Houghton, Thos. Harry, M. mst. c.5., M. 1. Mech. E., 63 Pitt-street. 1906 Howle, Walter Creswell, Medical Practitioner, Bega, N.S.W. 1904 Jaquet, John Blockley, a.n.s.M., F.G.s., Chief Inspector of Mines, Department of Mines. ie 1904 Jenkins, R, J. H., ‘Ettalong,’ Roslyn Gardens, Rushcutters Bay 1905|P8|Jensen, Harold Ingemann, p.sc, Government Geologist, Darwin, Northern Territory. 1907 Johnson, T. R., M. inst.c.z., Chief Commissioner of New South Wales Railways, Public Works Department. 1909 |P 13) Johnston, Thomas Harvey, m.a., D.sc., F.L,8., Biology Department, The University, Brisbane. 1902 Jones, Henry L, Assoc. Am. Soc., c.E. 14 Martin Place. 1867 Jones, Sir P. Sydney, Kut., s.p. Lond., F.R.c.s. Eng., ‘ Llandilo,’ Boulevard, Strathfield. 1911 Julius, George A., B. se, Me., Norwich Chambers, Hunter-street. | 1907 Kaleski, Robert, Agricultural Expert, Holdsworthy, Liverpool. 1883 Kater, The Hon. H. E., J.p., M.u.c., Australian Club. 1873 |P 3! Keele, Thomas William, m,inst.c.2, Commissioner, Sydney Harbour Trust, Circular Quay; p r. Llandaff-st., Waverley. 1887 | Kent, Harry C., M.A., F.B.1.B.A., Bell’s Chambers, 129 Pitt-st. 1991 Kidd, Hector, m. mst. ¢.E., M. 1. Mech. E., ‘ Craig Lea,’ 15 Mansfield- | street, Glebe Point. 1896 | | King, Kelso, 120 Pitt-street. 1878 Knaggs, Samuel T., m.p. Aberdeen, F.R.G.8. Irel., pie EEON: Bondi Road, Bondi. 1881 |P 22) Knibbs, G. H., ¢.M.G., F.S.s., F.R.A.S., Member Internat. Assoc. Testing Materials; Memb. Brit. Sc. Guild, Commonwealth Statistician, Melbourne. 1877 | Knox, Edward W., ‘ Rona,’ Bellevue Hill, Double Bay. (xviil.) Elected 1911 | P 2| Laseron, Charles Francis, Technological Museum. 1906 Lee, Alfred, Merchant, ‘Glen Roona,’ Penkivil-st., Bondi. 1909 | Leverrier, Frank, 8.a., B. sc. K.c,, 182 Phillip-street. 1883 | . Lingen, J. T., u.a. Cantab., 167 Phillip-street. 1872 |P 57 Liversidge, Archibald, M.A, Cantab, LL.D., F.R.S., Hon. F.R.S Edin., Assoc. Roy. Sch. Mines, Lond.; F.C.S,, F.G.8. F.R.G.8.3 | Fel. Inst. Chem. of Gt. Brit. and Irel.; Hon. Fel. Roy. Historical Soc. Lond.; Mem. Phys. Soc. Lond.; Mineral- | ogical Society, Lond.; Edin. Geol. Soc.; Mineralogical | Society, France; Corr. Mem. Edin. Geol, Soc.; New York Acad. of Sciences; Roy. Soc. Tas; Roy. Soc. Queensland ; Senckenbere Institute, Frankfurt; Société d’ Acclimat., Mauritius; Foreign Corr. Indiana Acad. of Sciences; Hon. Mem. Roy. Soc., Vict.; N. Z. Institute; K. Leop. Carol. Acad., Halle a/‘; ‘Hornton Cottage,’ Hornton-st., Kens- ington, London, W. 1906 Loney, Charles Augustus Luxton, M. Am. Soc, Refr.E, Equitable Building, George-street. 1911 Longmuir, G. F., B.a., Science Master, Technical College, Bathurst, 1884. MacCormick, Alexander, m.p., c.m. Edin., u.k.c.s. Eng., 185- Macquarie-street, North. 1887 MacCulloch, Stanhope H., c.m. Hdin., 24 College-street. 1878 MacDonald, Ebenezer, J.P., c/o Perpetual Trustee Co. Ld., 2 Spring-street. 1903 McDonald, Robert, s.e., ‘ Wairoa,’ Holt-street, Double Bay. 1891 McDouall, Herbert Chrichton, m.R.c.s. Eng., u.R.c.P. Lond., b.P.H. Cantab., Hospital for the Insane, Gladesville. 1906 | McIntosh, Arthur Marshall, Dentist, William-st., Chatswood. 1891 |P2| McKay, R. T., assoc. m. mst. 6.E, Geelong Waterworks and 4 Sewerage Trusts Office, Geelong, Victoria. 1893 McKay, William J. Stewart, B. sc., w.B., ch.m., Cambridge-street, Stanmore. 1876 Mackellar, The Hon. Sir Charles Kinnaird, m.t.c., M.8B., ¢.M. Glas., Equitable Building, George-street. 1904 McKenzie, Robert, Sanitary Inspector, (Water and Sewerage Board), ‘Stonehaven Cottage,’ Bronte Road, Waverley. 1880 | P 9| McKinney, Hugh Giffin, u.z., Roy Univ. Irel., m. mst.c.z., Aus- tralian Club, Macquarie-street. 1903 McLaughlin, John, Solicitor, Union Bank Chambers, Hunter-st. 1876 MacLaurin, The Hon. Sir Henry Normand, M.1.c., M.A., M.D.,. L.B.c.S, Hdin., LL.D. St. Andrews, 155 Macquarie-street. 1901 | P 1| McMaster, Colin J., Chief Commissioner of Western Lands; p.r. Wyuna Road, Woollahra Point. | McMillan, Sir William, k.c.m.a., ‘Althorne,’ 281 Edgecliffe Road, Woollahra. 1899 MacTaggart, J. N. C., mw. Syd., assoc. M. mst.c.e., Water and Sewerage Board District Office, Lyons Road, Drummoyne. 1894 ee Elected 1909 ( xix.) Madsen, John Percival Vissing’, b. sc, Bu, P. N. Russell Lec- turer in Electrical Engineering, Sydney University. 1883 |P 21] Maiden, J. Henry, J.p., r.u.s., Hon. Fellow Roy. Soc, S.A.; | | | | | | | | Hon. Memb. Nat. Hist. Soc., W.A., Netherlands Soc. for Promotion of Industry; Philadelphia College Pharm.; Southern Californian Academy of Sciences; Pharm. Soc. N.S.W.; Brit. Pharm. Conf.; Corr. Fellow Therapeutical Soc., Lond.; Corr. Memb. Pharm. Soc. Great Britain ; Bot. Soc. Edin.; Soc. Nat. de Agricultura (Chile); Soc. @ Horticulture d@ Alger; Union Agricole Calédonienne ; Soc. Nat, etc., de Chérbourg; Roy. Soc. Tas., Inst. Nat. Genévois ; Hon. Vice-Pres. of the Forestry Society of Cali- fornia; Diplomé of the Société Nationale d’ Acclimatation de France; Government Botanist and Director, Botanic Gardens, Sydney. President. Maitland, Louis Duncan, Dental Surgeon, 6 Lyons’ Terrace, Liverpool-street. P 1| Manfred, Edmund C., Montague-street, Goulburn. Marden, John, m.a., Lu.D., Principal, Presbyterian Ladies’ College, Sydney. Marshall, Frank, B.p.s. Syd., Dental Surgeon, 141 Elizabeth-st. P 27| Mathews, Robert Hamilton, L.s., Assoc. Etran. Soc. d’Anthrop. de Paris; Cor. Mem. Anthrop. Soc., Washington, U.S.A.; Cor. Mem. Anthrop. Soc. Vienna; Cor. Mem. Roy. Geog. Soc. Aust., Q’sland; Local Correspondent Roy. Anthrop. Inst., Lond.; ‘Carcuron, Hassall-st., Parramatta. Meggitt, Loxley, Manager Co-operative Wholesale Society, Alexandria. Miller, James Edward, Inverell, New South Wales. P 8| Mingaye, John C. H., F.1.c. F.c.s., Assayer aud Analyst to the Department of Mines; p.r. Campbell-street, Parramatta. Moore, Frederick H., Union Club, Sydney. ¢Mullens, Josiah, F.x.a.s., ‘ Tenilqa,’ Burwood. Mullens, John Francis Lane, m.a. Syd., ‘ Killountan,’ Challis Avenue, Pott’s Point. Myles, Charles Henry, ‘ Dingadee,’ Everton Rd., Strathfield. P 2| Nangle, James, Architect, ‘St. Elmo,’ Tupper-st., Marrickville. tNoble, Edward George, Public Works Department, Newcastle. Noyes, Edward, assoc. M. Inst. C.E., Assoc. I. Mech. B., ¢/0 Messrs. Noyes Bros., 109 Pitt-street. Old, Richard, Solicitor, ‘ Waverton,’ Bay Rd., North Sydney. Onslow, Lt. Col. James William Macarthur, Camden Park, Menangle. O’Reilly, W. W. J., m.v., uch, Q. Univ. Irel., m.R.c.s. Eng., 171 Liverpool-street, Hyde Park. Osborn, A. F’., Assoc. M. Inst.c.e.. Water Supply Branch, Sydney, Owen, Rev. Edward, s.a., All Saints’ Rectory, Hunter’s Hill. | | | ‘Linton,’ Parkes-street, Ryde. Electei 1880 1878 1906 1901 1899 1877 1899 1909 1879 1896 1881 1879 1887 1896 1910 1893 1901 1908 1876 1890 1862 1906 1909 1902 1906 1884 1895 1904 1882 1897 1893 Pl P7 P8 PA — (xx.) | Palmer, Joseph, 96 Pitt-st.; p.r. Kenneth-st., Willoughby. | Paterson, Hugh, 183 Liverpool- street, Hyde "Park. Pawley, Charles Lewis, Dentist, 187 Regent-street. | Peake, Algernon, Assoc. M. Inst. C.B., 25 Prospect Road, Ashfield. Pearse, W., Union Club; p.r. ‘ Plashett,’ Jerry’s Plains, via Singleton. Pedley, Perceval R., Australian Club. Petersen, T. Tyndall, Member of Sydney Institute of Pubiic Accountants, Copper Mines, Burraga. Pigot, Rev. Edward F., s.J., B.a., M.B., Dub., St. Ignatius College, Riverview. Pittman, Edward F., Assoc. R.S.M., L.S., Under Secretary and Government Geologist, Department of Mines. Plummer, John, ‘ Northwood,’ Lane Cove River; Box 413 G.P.O. Poate, Frederick, Surveyor-General Lands Department, Sydney Pockley, Thomas F. G., Union Club, Sydney. Pollock, J. A., D.Se., Cont Memb. Roy. Soc., aetna Roy. Soc. Queensland ; Professor of Physics in the University of Sydney. Hon. Secretary. Pope, Roland James. B.a. Syd., M.D., O.M., F.B.C.S. Hdin., Ophthalmic Surgeon, 235 Macquarie-street. Potts, Henry William, F.u.s., ¥.c.s., Principal, Hawkesbury Agricultural College, Richmond, N.S.W. Purser, Cecil, B.A., M.B., Ch.M. Syd., ‘Valdemar,’ Boulevard, Petersham. Purvis, J. G. S., Water and Sewerage Board, 341 Pitt-strect. Pye, Walter George, M.A., B. Se. N ield Avenue, Paddington. Quaife, F. H., m.a., M.D., m.s., ‘Hughenden,’ 14 Queen-street, Woollahra. Vice- President. Rae, J. L. C., ‘ Lisgar,’ King-street, Newcastle. tRamsay, Edward P., uu:p. St. And., F.B.S.E., B.L.S., 8 Palace- street, Petersham. Redman, Frederick G., P. and O. Office, Pitt-street, Rhodes, Thomas, Civil Engineer, Carlingford and Public Works Department. Richard, G. A., Mount Morgan Gold Mining Co. Mount Morgan, Queensland. Richardson, H. G. V., 32 Moore-street. Ross, Chisholm, m.p. Syd., m.B., c.m. Edin., 147 Macquarie-st. Ross, Herbert E., Equitable Building, George-street. Ross, William J. Clunies, B.se, Lond. & Syd., ¥.c.s., Lecturer in Chemistry, Technical College, Sydney. pe W. H., Colonial Sugar Co., O’ Connell-street, and Union Club. Russell, Harry Ambrose, 8.a., Solicitor, ¢/o Messrs. Sly and Russell, 369 George-street ; p.r. ‘ Mahuru,’ Pajatae Road, Bellevue Hill. Rygate, Philip, W., M.a., B.e. Syd., Assoc. M. Inst. C.E., 164 Pitt-st. (xxi. ) Elected 1905 Scheidel, August, Ph.D, Managing Director, Commonwealth Portland Cement Co., Sydney; Union Club. 1899 Schmidlin, F., 39 Phillip-street, City. 1892 | P 1! Schofield, James Alexander, F.c.s., A.R.S.M., Assistant Pro- fessor in Chemistry, University, Sydney. 1856 | P 1 |{Scott, Rev. William, m.a. Cantab., Kurrajong Heights. 1904 | P 1] Sellors, R. P., B.a, Syd., ‘Cairnleith,’ Military Road, Mosman. 1908 Sendey, Henry Franklin, Manager of the Union Bank of Australia Ld., Sydney; Union Club. 1883 | P 4| Shellshear, Walter, M. Inst. C.E., Inspecting Engineer, Existing Lines Office, Bridge-street. 1905 Simpson, D. C., M. Inst.c.E., N.S. Wales Railways, Redfern ; p.r. *Clanmarrina,’ Rose Bay. 1900 Simpson, R. C., Technical College, Sydney. 1910 Simpson, William Walker, Merchant, Leichhardt-st. more 1882 Sinclair, Eric, u.p., o.M. Glas., Inspector-General of Insane, 9 Richmond ieerice: Domain ; p.r. ‘ Broomage,’ Kangaroo- street, Manly. 1893 Sinclair, Russell, M.I. Mech.E,, Vickery’s Chambers, 82 Pitt-st. 1891 | P 3| Smail, J. M., M.Inst.c.z., Chief Engineer, Metropolitan Board of Water Supply and Sewerage, 341 Pitt-street. | 1893 |P 39| Smith, Henry G., r.c.s., Assistant Curator, Technological Museum, Sydney. 1874 | P 1\{Smith, John McGarvie, 89 Denison-street, Woollahra. 1892 | P 1| Statham, Edwyn Joseph, Assoc, M. Inst. C.E., Cumberland Heights, Parramatta. 1900 Stewart, J. Douglas, B.v.sc., M.R.c.v.s., Professor of Veterinary Science, The University of Sydney; ‘ Berelle,’ Homebush Road, Strathfield. 1903 Stoddart, Rev. A. G., The Rectory, Manly. 1909 Stokes, Edward Sutherland, M.A, Syd., F.R.C.P.S. Ivrel., Medical Officer, Metropolitan Board of Water Supply and Sewerage, 341 Pitt-street. 1883 | P 4| Stuart, T. P. Anderson, m.p., ut.p. Hdin., Professor of Physi- ology, University of Sydney; p.r. ‘ Lincluden,’ Fairfax Road, Double Bay. 1901 | P 4| Siissmilch, C. A., F.e.s., Technical College, Sydney. 1906 Taylor, Sir Allen, ‘ Woolton,’ Darley-street, Darlinghurst. 1906 | Taylor, Horace, Registrar, Dental Board, 7 Richmond Terrace, Domain. 1905 Taylor, John M., m.a., LL.B. Syd., ‘ Woonona,’ 43 East Crescent- street, McMahon’s Point, North Sydney. 1893 f{Taylor, James, B.sc., a.R S.u., ‘Adderton,’ Dundas. 1899 Teece, R., F.1.A., F.F.A., General Manager and Actuary, A.M.P. Society, 87 Pitt-street. 1861 |P 19) Tebbutt, John, ¥.R.a.s., Private Observatory, The Peninsula, Windsor, New South Wales. 1878 Thomas, F. “di; Newcastle and Hunter River Steamship Co., 147 Sussex-street. 1879 Thomson, Hon. Dugald, u.u.R., Carrabella-st., North Sydney. 1885 | P 2} Thompson, John Ashburton, u.p. Bruz., D.P.H. Cantab., M.R.C.S. _ Eng,, Health Department, Macquarie-street. 1896 Thompson, Capt. A. J. Onslow, Camden Park, Menangle. Elected 1892 1894 1879 1900 1883 1890 1892 1903 1907 1879 1899 1910 1910 1910 1901 1891 1903 1901 1898 1883 1876 1876 1910 1910 1911 1908 1910 1897 1903 1892 P 2| Vonwiller, Oscar U., B.sc., Assistant Lecturer and Demonstrator Pl P2 Ply Pl (xxii.) Thow, William, M. Inst. C.E., M. I. Mech. E., ‘ Inglewood,’ Lane Cove Road, Wahroonga. Tooth, Arthur W., Kent Brewery; 26 George-street, West. Trebeck, P. C., F. R. Met. Soc., 12 O’Connell-street. Turner, Basil W., a.R.s.M., ¥.c.S., Victoria Chambers, 83 Pitt-st.. Vause, Arthur John, u.B., c um. Edin., ‘ Bay View House,’ Tempe. Vicars, James, m.z., Memb. Int. Assoc. Testing Materials; Memb. B.S. Guild; Challis House, Martin Place. Vickery, George B., 78 Pitt-street in Physics, University of Sydney. Waley, F. G., Assoc. M. Inst.C.E., Royal Insurance Building, Pitt-st. Walker, H. O,, Commercial Union Assurance Co., Pitt-street. tWalker, Senator The Hon. J. T., ‘ Wallaroy,’ Edgecliffe Road,. Woollahra. Walker, Charles, Metallurgical Chemist, etc., ‘ Kuranda,’ Waverley-street, Waverley. Walker, Harold Hutchison, Major St. George’s English Rifle: Regiment, c.m.F., ‘ Vermont,’ Belmore Road, Randwick. Walkom Arthur Bache, B.Sc. Junior Demonstrator in (xeology, Sydney University; p.r. ‘ Lang-hay,’ Fisher-st., Petersham. Walkom, A. J., A.m.1.£.8., Electrical Branch, G.P.O., Sydney. Walsh, Henry Deane, B.a.1., Dub., M.lust.0.E., Engineer-in- Chief, Harbour Trust, Circular Quay. Vice-President Walsh, Fred., George and Wynyard-streets ; p.r. ‘ Walsholme,’ Centennial Park, Sydney E. Walton, R. H., F.c.s., ‘ Flinders,’ Martin’s Avenue, Bondi. Wark, William, Assoc. M.Inst.c.E, 9 Macquarie Place; p.r. Kurrajong Heights. Warren, W. H., Wh. Sc., M. Inst, C.E., M. Am. Soc. C.E., Member of Council of the International Assoc. for Testing Materials, Professor of Engineering, University of Sydney. Watkins, John Leo, B.A. Cantab., m.a. Syd., Parliamentary Draftsman, Attorney General’s Department, Macquarie-st. Watson, C. Russell, m.z.c.s. Eng., ‘ Woodbine,’ Erskineville. Watson, James Frederick, M. B.,Ch.M., Australian Club, Sdyney. Watt, Francis Langston, F.1.c., A.R.c.s., 10 Northcote Cham- bers, off 163 Pitt-street, City. Watt, R. D., M.A,BSc, Professor of Agriculture, University of Sydney. Weatherburn, Charles Ernest, M.A, B.Sc, Syd., B.A. Cantab.,. Ormond College, Parkville, Melbourne. Wearne, Richard Arthur, B.a., Principal, Technical College, Ipswich, Queensland. Webb, Frederick William, c.m.a., J.p., ‘ Livadia,’ Manly. Webb, A. C. F., w1.8.5., Vickery’s Chambers, 82 Pit-street. Webster, James Philip, Assoc. M. Inst. C.E., L,S., New Zealand, Towa Hall, Sydney. Elected 1907 1907 1881 1892 | 1877 1909 1879 1907 1876 1908 1901 1890 1891 1906 1909 1900 1905 1911 1901 1908 1908 1905 |. 1894 1900 Pl EG (xxiii.) Weedon, Stephen Henry, c.z., ‘ Kurrowah,’ Alexandra-street, Hunter’s Hill. Welch, William, r.r.a.s., ‘ Roto-iti,’ Boyle-street, Mosman. [Wesley, W. H., London. White, Harold Pogson, F.c.s., Assistant Assayer and Analyst, Department of Mines; p.r. ‘Quantox,’ Park Road, Auburn. ~White, Rev. W. Moore, a.m., Lu.D., Dub. White, Charles Josiah, Science Lecturer, Sydney Training College; p.r. ‘ Patea,’ Miller Avenue, Ashfield. ¢{Whitfeld, Lewis, m A. Syd., ‘ Sellinge,’ Albert-st., Woollahra. awater, William, _Kenyon,: Kurraba Point, Nontrar Bay. Williams, Percy Edward, ‘St. Vigeans,’ Dundas. Willis, Charles Savill, M.B.Ch.M. Syd., M.R.c.s. Eng., L.R.C.P. Lond., pv.H., Roy: Coll. P. & S. Lond., Department of Public Health. Willmot, Thomas, s.P., Toongabbie. Wilson James T., M.B., Ch.M, Edin., F.R.S., Professor of Anatomy, University of Sydney. Wood, Percy Moore, t.kr.c.P. Lond., M.R.¢.s. Eng., ‘ Redcliffe,’ Liverpool Road, ‘Ashfield. Woolnough, Walter George, D.Sc. F.G.s., Assistant Professor and Demonstrator in Geology, University of Sydney. Yeomans, Richard John, Solicitor, 14 Castlereagh-street. HonorAaRY MzMBERS. Limited to Thirty. M.—Recipients of the Clarke Medal. Crookes, Sir William, Kt., 0.u., LL.D., D.Sc., F.R.S., 7 Kensington Park Gardens, London W. Fischer, Emil, Professor of Chemistry, University, Berlin. Hemsley, W. Botting, r.z.s., Formerly Keeper of the Herbar- ium, Royal Gardens, Kew, 24 Southfield Gardens, Straw- berry Hill, Middlesex. Judd, J.W., ¢.B., LL.D., F.R.S., F.G.S., Formerly Professor of Geology, Royal College of Science, London; 30 Cumber- land Road, Kew, England. Kennedy, Sir Alex. B. W., Kt., uu.p., D. Eng., F.R.S., Emeritus Professor of Engineering in University College, London, 17 Victoria-street, Westminster, London S.W. Liversidge, Archibald, M.A., LL.D., F.R.S., Emeritus Professor of Chemistry in the University of Sydney, ‘ Hornton Cottage,’ Hornton-street, Kensington, London S.W. Oliver, Daniel, Lu.pD., F.R.s., Emeritus Professor of Botany in University College, London. Spencer, W. Baldwin, c.m.a, M.A., F.R.S., Professor of Biology in the University of Melbourne. M | Thiselton-Dyer, Sir William Turner, K.c.M.G., C.1.E., M.A., LL.D., Se. D., F.B.S., The Ferns, Witcombe, Gloucester, England. (xxiv), Elected 1908 Turner, Sir William, K.c.B., M.B., D.C.L., LL.D., Sc. D., F.R.C.8. Edin., ¥.8.8., Principal and Emeritus Professor of the University of Edinburgh, 6 Eton~ Terrace, Edinburgh, Scotland. 1895 Wallace, Alfred Russel, 0.M., D.c.L., LL.D., F.R.S., Old Orchard, Broadstone, Wimborne, Dorset. OBITUARY 1910. Honorary Members. 1875 Bernays, Lewis A. 1880 Hooker, Sir Joseph Dalton. 1903 Lister, Right Hon. Joseph, Lord. Ordinary Members. 1879 Chard, J. S. 1884 Jones, Llewellyn Charles Russell. 1876 Josephson, J. Percy. 1883 Osborne, Ben. M. 1906 Oschatz, Alfred Leopold. 1876 Voss, Houlton H. 1867 Weigall, Albert Bythesea. AWARDS OF THE CLARKE MEDAL. Established in memory of THE LATE Revp. W. B. CLARKE, m.a., F.R.S., F.G.S., etc., Vice-President from 1866 to 1878. To be awarded from time to time for meritorious contributions to the Geology, Mineralogy, or Natural History of Australia. The prefix * indicates the decease of the recipient. Elected 1878 *Professor Sir Richard Owen, K.¢c.B., F.R.S. 1879 *George Bentham, c.M.G., F.R.S. 1880 *Professor Thos. Huxley, F.R.s. 1881 *Professor F. M’Coy, F.R.S., F.G.S. 1882 *Professor James Dwight Dana, LL.D. 1883 *Baron Ferdinand von Mueller, k.c.M.G., M.D., PH.D., F.R.S., F.L.8. 1884 *Alfred R. C. Selwyn, LL.D., F.R.8S., F.G.S. 1885 *Sir Joseph Dalton Hooker, 0.M., G.c.s.1.,C.B., M.D.,D.C.L., LL.D.,F.B.S- 1886 *Professor L. G. De Koninck, m.p., University of Liége. 1887 *Sir James Hector, K.c.M.G., M.D,, F.R.S. 1888 *Rev. Julian EK. T'enison-Woods, F.G.S., F.L.S. 1889 *Robert Lewis John Ellery, F.R.s., F.R.A.S. (xxv.) Elected, 1890 *George Bennett, m.p., F.R.c.s. Hng., ¥.L.S., F.Z.8. 1891 *Captain Frederick Wollaston Hutton, F.R.s., ¥.a.s. 1892 Sir William Turner Thiselton Dyer, k.c.M.G.,C.1.E.,M.A., LL.D., Sc. D., F.B.S., F.L.S., late Director, Royal Gardens, Kew. 1893 *Professor Ralph Tate, Fr...s., F.G.s. 1895 Robert Logan Jack, Fr.a.s., F.R.G.s., late Government Geologist, Brisbane, Queensland. 1895 Robert Etheridge, Junr., Curator of the Australian Museum, Sydney 1896 *Hon. Augustus Charles Gregory, 0.M.G., F.R.G.S. 1900 Sir John Murray, K.c.B., LL.D., Sc.D., F.R.8., Challenger Lodge, Wardie, Edinburgh. 1901 *Edward John Eyre. 1902 F. Manson Bailey, F.u.s., Colonial Botanist of Queensland, Brisbane. 1903 *Alfred William Howitt, p.sc., F.G.S. 1907 Walter Howchin, r.a.s., University of Adelaide. (1909 Dr. Walter E. Roth, 8.a., Pomeroon River, Britisb Guiana, South - America. AWARDS OF THE SOCIETY’S MEDAL AND MONEY PRIZE. The Royal Society of New South Wales offers its Medal and Money Prize for the best communication (provided it be of sufficient merit) containing the results of original research or observation upon various subjects published annually. Money Prize of £25. 1882 John Fraser, B.a., West Maitland, for paper on ‘ The Aborigines of New South Wales.’ 1882 Andrew Ross, u.p., Molong, for paper on the ‘ Influence of the Australian climate and pastures upon the growth of wool.’ The Society’s Bronze Medal and £25. 1884 W. E. Abbott, Wingen, for paper on ‘ Water supply in the Interior of New South Wales.’ 1886 S. H. Cox, F.a.s., F.c.s., Sydney for paper on ‘The Tin deposits of New South Wales. 1887 Jonathan Seaver, r.a.s., Sydney, for paper on ‘ Origin and mode of occurrence of gold-bearing veins and of the associated Minerals. 1896 Thomas Whitelegge, ¥.R.m.s., Sydney, for ‘ List of the Marine a1 Fresh-water Invertebrate Fauna of Port Jackson and Ne - bourhood. . fi Rev. John Mathew, m.a., Coburg, Victoria, for Paper on ‘ Th e Australian Aborigines. , Rev. J. Milne Curran, F.c.s., Sydney, for paper on ‘ The Microscopie "i Structure of Australian Rocks.’ 1 Alexander G. Hamilton, Public School, Mount Kembla, for paper | °: on ‘The effect which settlement in A uepEEae has produced — upon Indigenous Vegetation.’ J. V. De Coque, Sydney, for paper on the ‘ Tighe of era South | - Wales.’ . ae R. H. Mathews, u.s., Parramatta, for paper on ‘The Aboriginal 4 Rock Carvings and Paintings in New South Wales.’ GC. J. Martin, psc, MB, F-R.s., Sydney, for paper on ‘The — Be physiological action of the venom of the Australian black — snake (Pseudechis porphyriacus).’ a Rev. J. Milne Curran, Sydney, for paper on ‘The occurrence of Precious Stones in New South Wales, with a description of the Beno: in which they are found.’ 4 i ot ] a, RNG v7 f ‘ “ay » ree! A 2 OSS ae ¥ < ; pte p> nt’ Fp rs bs . i ae ? a . ¥ . 3 7 ISSUED OCTOBER 24th, 1911. st Vol. XLV, : oO Ge Part I. JOURNAL AND PROCEEDINGS | ROYAL SOCIETY OF NEW SOUTH WALES; FOR LOTT: PART I., (pp. 1-64). \ CONTAINING PAPERS READ IN MAY to JUNE (in part.) WITH THREE PLATES. (Plates i, ii, iii) -~SYDNEY : * PUBLISHED BY THE SOCIETY, 5 ELIZABETH STREET NORTH, SYDNEY. M ; s LONDON AGENTS : 5 GEORGE ROBERTSON & Co., PROPRIETARY LIMITED, a aoe. 17 Warwick Squar:,. PATERNOSTER Row, Lonpon, E.C. 3 re 1911. |e F, WHITE: Typ., 344 Kent Street Sydney. PRESIDENTIAL ADDRESS. bi ; @ By T. W. EDGEWORTH DAVID, C.M.G., B.A. F.R.S., Hon. D.Sc. Oxon. With Plates I, II. [ Delivered to the Royal Society of N. 8. Wales, May 3, 1911. |] _ THE privilege having once more been accorded me of addressing you as your President, I propose on this, the ninetieth anniversary of the existence of our Society, to touch briefly on the history of the Society during the last twelve months, then to offer some notes on the chief - tectonic lines of Australia in particular and Australasia in - general. I—Royal Society of New South Wales. The number of members on the roll on the 30th of April, 1911, was 315; 12 new members were elected during the _ past year. We have, however, lost by death two ordinary members and two honorary members, and nine by resigna- tion. There is thus left a total of 316 members. This _ number, however, does not include the 14 honorary mem- bers. The losses by death were—Honorary Members, Sir William Huggins, Upper Tulse Hill, London, and Stanislao Cannizzaro, Reale Universite, Rome. Ordinary Members, Dr. Walter Spencer and W. J. MacDonnell. Dr. WALTER SPENCER, M.D. Brux., was for fourteen years a member of our Society, and for seven years was a member of our Council, whose meetings he attended with great regularity. Dr. Spencer is probably best known to our scientific world as the President of the British Science Guild, a position which he occupied at the time of his death | last year in Mexico City. He was most enthusiastic in his devotion to the work of that body, and was chiefly instru- mental in moving the Government of this State to provide A—May 3, 1911. 2 T. W. E. DAVID. increased ground space for the recreation of children, especially school children. His efforts at securing better methods for the carriage of stock for our Sydney Meat Supply further proves how near was the health and general welfare of the community to his heart. Throughout the whole of his life amongst us he proved himself to be a most conscientious and sympathetic worker in the cause of humanity no less than in that of science. Wa. JoHN MAcDONNELL, Fellow of the Royal Astronomical Society, was a member of our Society for forty-two years. An active member of the British Astronomical Association he was president for two years and secretary of the New South Wales Branch for several years, occupying that post when he died. He wasamost enthusiastic amateur astro- nomer. His memory was remarkable, he could quote volume and almost page for hundreds of articles which he had read in the English Mechanic. Years ago when the Royal Society had an astronomical section, he was at that time one of its most active members. He participated in one of the Transit of Venus Expeditions. He was also a keen numismatist, making a specialty of Greek coins. In regard to our Library it may be stated that books and periodicals have been purchased this year at a cost of £41 13s. 7d. A great number of unbound books and peri- odicals are about and will continue to be bound in a cheap style of binding in order to make them accessible to the members. The number of Institutions on the exchange list numbers 429, and the publications received in exchange for the Society’s Journal and Proceedings during the year were 222 volumes, 1815 parts, 161 reports, 282 pamphlets, and 20 maps, making a total of 2,500. | During the past year the Society held eight meetings at which 32 papers were read, the average attendance of the members being 34. = =~ v PRESIDENTIAL ADDRESS. 3 The following is a list of the series of Popular Science Lectures, illustrated by lantern slides etc., and of the Lecturers during 1910:—‘'The Velocity of Chemical Changes,’’ by Professor Fawsitt, p.sc., F.c.S.;_ “‘Harly Blue Mountain Exploration, (Barallier’s furthest West) by Mr. R. W. Cambage, L.s.; “‘The Mountains of New South Wales, their nature and origin,’ by Mr. C. A. Sussmilch, F.6.s.; **Modern Methods of Recording Harthquakes,’’ by Rev. E. F. Pigot, B.A., M.B., S.J.; “‘The Social View of Capital,”’ (two lectures), by Mr. R. F. Irvine, M.A. The excellent attendance at these lectures, and the enthusiastic way in which they were received is proof of their usefulness, and the hearty thanks of our Society are due to the lecturers who have so unselfishly placed their services at the disposal of our Society for the sake of the advancement of science. May I also on your behalf and my own, express on this occasion, our deep gratitude to the Hon. Secretaries, Mr. J. H. Maiden, F.L.s., and Mr. F. B. Guthrie, F.1.c., as well as to the Hon. Treasurer, Mr. David Carment, F.1.A., for their unremitting and generous services in the best interests of our Society. It issatisfactory to note that the finances of the Society are sound. On the occasion of my recent visit to Hngland, it was my privilege on several occasions to meet our old colleague, whom we have all come to look upon as a second founder of this Society, Professor Liversidge, and members will be pleased to hear that he is in excellent health and engaged in active research on lines made familiar to us by so many of his papers published in our journal. He desired me to convey his kindly greetings to all the members, greetings which, I am confident we all heartily reciprocate. It was obvious that he had played an important part together with Professor Masson of Melbourne, Professor Martin of the Lister Research Institute, R. Threlfall (late 4 T. W. E. DAVID. Professor of Physics at the University of Sydney) Professor J. P. Hill and others of our former colleagues in so success- fully pressing the invitation of the science bodies of Aus- tralia to the British Association for the Advancement of Science to come over and visit us in 1914. It was also obvious from the names mentioned of the intending visitors that the British Association would be well and worthily represented on what we all hope will bea happy and helpful meeting between the old world and the new. II—Notes on some of the Chief Tectonic Lines of Australia. | The relief model of Australia reproduced on Plate 1, and the lines of section which accompany it, represent some of the chief structural trend lines which have presented themselves to one’s notice up to the present. Suess in his magnificent and monumental work, “‘ Das Antlitz der Erde,’’ has already furnished a masterly sketch of some of the main trend lines of Australasia.’ The late Captain FY. W. Hutton, F.R.s., has furnished an excellent and succint account of the chief structural fea- tures of New Zealand.” The Horn Expedition to Central Australia threw much light on its dominant trend lines.® In 1893, in a Presidential Address to the Linnean Society, I attempted to sketch from somewhat meagre data the then state of our knowledge of the leading trend lines of Australia.* Professor Gregory, F.R.S., has indicated some of the chief trend lines of Victoria.” Mr. W. H. Twelve- trees, F.G.S., the Government Geologist of Tasmania and 1 Suess, The Face of the Earth, Translation by Hertha, B. C. Sollas and W. J. Sollas, Vol. 1, pp. 149-164; and Vol. trv, pp. 301 - 321 and 501. 2 Q.J.G.8S., May, 1885, Sketch of the Geology of New Zealand, by Capt. F. W. Hutton, F.a.s., pp. 191 - 220, figs. 1-4. ? Report of the Horn Exploring Expedition in Central Australia, Geology by Prof. Ralph Tate and J. A. Watt, B.a., Bsc, pt. 3, pp. 1-81 * Proc. Linn. Soc., 1894, Vol. vir1, Ser. 2, pp. 540 - 607, pls. xxvii, xxviii. § Geography of Victoria, Whitcombe and Tombs. By Professor J. W. Gregory, F.R.S. PRESIDENTIAL ADDRESS. 5 Mr. G. A. Waller have done similar work for Tasmania.? Still more recently Mr. E.C. Andrews,’ Mr.C. A. Stissmilch,? and Mr. OC. Hedley,* have dealt with the physiography, epeirogenic uplifts, disjunctive lines, and warping of New South Wales. In a later paper Mr. H. C. Andrews’ has summed up our knowledge of recent and Tertiary earth movements in Hastern Australia and Tasmania. Mr. Walter Howchin, F.G.s.,° has greatly added to our knowledge of the tectonic lines of South Australia. Mr. A. Gibb Maitland, F.G.s., the Government Geologist of South Aus- tralia, has summed up avast amount of information obtained by himself and the officers of his survey on the geological structure of West Australia in his presidential address to the Australasian Association for the Advancement of Science,’ and aiso in his recent paper on ‘‘ The Foundation Stones of West Australia.’’ He has also contributed for my present address a valuable note on the chief lines of fault traversing that State. In regard to Queensland. nearly all our knowledge of its structural features are contained in the reports of the Geological Survey, notably those by Dr. R. L. Jack, F.G.s., Messrs. W. H. Rands, F.G.s., and B. Dunstan, F.G.s. For the structure of Northern Territory the chief information is given in the official reports by Mr. H. Y. L. Brown, A.R.S.M. F.G.S., Government Geologist of South Australia, and by his assistant Mr. Basedow, B. sc. ° + Report Austr. Assoc. Adv. Sci., Dunedin, 1904, pp. 613, 622 — 629. * Physical Geography of New South Wales. by EH. C. Andrews, B.A., pp. 55 — 94. * This Journal, Vol. xu111, 1909, pp. 331 - 354, pls. ix — xiv. * Proc. Linn. Soc. N. S. Wales, Presidential Address, Vol xxxv, 1910 and ibidem Vol. xxxvi, pp. 9- 21, pls. i, ii. & This Journal, Vol. xuiv, pp. 420—480, figs. 1,2, The Physiographic Unity of Eastern Australia, by E C. Andrews, BA. ° The Geography of South Australia, by Walter Howchin, F.G.s., edited by Professor J. W. Gregory, 1909; also see Howchin, Journ. Roy. Soe. S. Australia, Vol. xxvii, pp. 253 — 280, pls. xxxvii -xliv, and Vol. xxx, pp. 227 - 262, pl. xii; also Q.J.G.S., Vol. uxrv, pp. 234 - 258, pls. xix — xxvi. 7 Report Austr. Assoc. Advt. Sci., Adelaide, 1907, Presidential Address by H. Gibb Maitland, r.a.s., pp. 181 - 187. ® Report on the Geology of Northern Territory, By Authority. Adelaide 1895 and 1906. 6 T. W. E. DAVID. It may be added that in the matter of late epeirogenic uplifts of Australia much light has been shed by the paleeon- tological researches of Messrs. R. Etheridge and W. S. Dun; and new and promising line of investigation bearing on recent movements of the Hast Australian coast line based on the present distribution of our forest trees in relation to soils and geological formations has been insti- tuted by Mr. R. H. Cambage, Ls.’ The excellent seismograph records now being published from time to time by the Rev. EK. F. Pigot, s.J., from the Seismograph Observatory at St. Ignatius College, Riverview are yielding invaluable information as to the areas of modern re-adjustment of the earth’s crust in the neighbour- hood of Australia. Other references will be given in their proper place throughout this address. The relief map of Australia and Tasmania reproduced on Plate 1, was specially prepared for this address by Mr. W.K. McIntyre of Sydney University, from data generously placed at our disposal by Mr. H. EH. C. Robinson, to whom Australian cartography is very deeply indebted. In this relief map the following features at once arrest attention : (1) The strongly marked eastern ranges approaching so closely to the coast near Cape Howe and in the neighbour- hood of Hinchinbrook Island and the Bellenden-Ker Ranges. (2) The broad basin lying to their west extending from the Gulf of Carpentaria to the Australian Bight with the eastern branch of the Darling-Murray Basin, and the immense western extension around the head of the Great Australian Bight as far west asCape Arid. The boundary on the south of the Darling-Murray Basin introduces us to a new tectonic element, (3) The Victorian Main Divide in which an east to west line of warping or uplift has domin- ated the older meridional lines, an uplift which is comple- * Report Austr. Assoc. Adv. Sci., Vol. x1, pp. 473 - 483. PRESIDENTIAL ADDRESS. 7 mentary to the inthrow of the parallel and adjacent structure of (4) Bass Strait. The boundary of the Darling- Murray Basin on the west reveals element (5), the great fork of the Mount Lofty and Flinders Ranges thrust far north into the great basin. The deep indents of St. Vincent and Spencers Gulfs and the basins of Lakes Torrens and Kyre, suggest strong tectonic disturbances extending from here towards the Gulf of Carpentaria. The main western boundary of the Great Basin is (6) the plateau of Central Australia, Northern Territory and West Australia, accentuated at its eastern edge by the strong east and west trend lines of the MacDonnell and Musgrave Ranges, and terminating south-westwards in the Darling Range peneplain, interrupted by the bold blutfis of the Stirling Range. The western boundary of the Darling Range is followed further west by what Mr. Gibb Maitland has shown to be one of the most remarkable tectonic features of Australia, a deep, long and narrow rift valley. Cape Leeuwin and Cape Naturaliste lie on the west side of this valley, the deep indent between Cape Naturaliste and Bunbury being due to this tectonic feature. I cannot do better than here quote Mr. A. Gibb Maitland’s account of this feature as well as on other fault lines in West Australia: “In the short time available it has been found quite im- possible to wade through the forty-one bulletins and fifteen annual reports of the Geological Survey. The following however, are the more important main fault lines, so far as is known :—1. The face of the Darling Range from the South Coast to somewhere about Minginew (S. Lat. 29 —34°) appears to be marked bya major fault, which there is some reason for believing marks the eastern wall of a long “rift valley,’’ of which probably part of the western wall is to be found in that narrow ridge of ancient crystalline rocks from Flinders to Geographe Bay. The fundamental rocks 8 T. W. E. DAVID. of the islands of Rottnest and Houtmens Abrolhos possibly mark the northward extension of these latter. The eastern fault which forms the escarpment of the range brings the palaeozoic and newer rocks in juxtaposition to the ancient crystalline schists, which are believed to be of Archaean Age. The sedimentary rocks which fill this “‘ rift valley ” are so arranged that there is a gradually ascending series southwards from the Irwin River Coal Field. Cretaceous rocks outcrop at Gin Gin, they have been met with in some of the bores in the metropolitan area, beneath Perth, and also rise to the surface to the southward along the coastal plain. The most recent beds in this “ rift vailley’’ make their appearance near Bunbury, and are associated with more or less horizontal sheets of basalt, these latter out- crop at Bunbury, at several places in the bed of the Black- wood and the south coast between Cape Leeuwin and Cape D’EHntrecasteaux, they have also been met with in a bore put down in the valley of the Donnelly River. There seem reasons for believing these to be contemporaneous with the bedded basalts of South Australia and Victoria, if so then it is very likely that this fault is Late or Post Tertiary. **2. On the Warrawoona Field, Pilbarra Gold Field, (Bull. 40, plate 10, of reprint of Bulls. 15, 20, and 23) a very marked fault at least six miles in length, traverses the field ina N.W. and 8.H. direction, and probably extends far beyond the limits of the area mapped. The fault hades to the N.E. at about 60 degrees. A glance at the map shews several bands of quartzite disposed somewhat in the Shape of a fan, the ribs of which open out gradually to the west. The peculiar mode of occurrence, and ending off of these beds is strongly suggestive of this line marking an important fault, which, however, makes no show at all on the surface. Further evidence of this hypothesis is to be PRESIDENTIAL ADDRESS. 9 found in the fact that the continuity of the newest diabase dykes, which cross the field ina direction about north-east and south-west, is very materially affected. Many of the rocks are sheared, and the quartz reefs folded and over- thrust, all of which points to this being a region of great dynamic movement. “3. The Warrawoona belt extends northwards fifteen miles to Marble Bar, which field is also traversed by at least four major faults, which have a general northerly strike. These faults have played great havoc with the newer diabase dykes, as may be seen by an inspection of the geological map (pl. 14, Bull. 40). Of the age of the faulting both here and at Warrawoona, there is no direct evidence, other than that it is younger than that of the newest diabase dykes, of whatever age they may be. “4, The Collie Coal Field is bounded by two faults trend- ing generally north-west and south-east. The faults are of considerable horizontal extent as well as of great down- throw. Iam rather inclined to regard the boundaries of the great Stirling Range, as marking the extension of the Collie group of faults.’ The trend and positions of these lines of faults are shown on Plate 2, and the rift valley and the folds in the adjacent peneplain are shown in figure 1. Fis. | DIAGRAMMATIC SECTION ACROSS THE GREAT TROUGH FAULT OF West AUSTRALIA. from data suggested by AGibb-Maitland F.G.S. Vertical Scale B.UQ0 feet to an inch. Fremantle Perth Darling ETRE Indian Ocean [zs w erey ea a SCHIST\, Pte = & GNEISSIC Ty he fe | ry GRANITE \ “S 4 Perlh Bunbury Geraldton Dongara FiG.2. LONGITUDINAL SECTION OF ABOVE. Fe TT RECENT..OUNE? ROCK. 02: : > eee 44 4 eee AS Sic LI Sr tg ous pee t 4 CARBONT = GNEISSIC GRANITE Pe a REREUS. naa gpscaasa gaa 3 ogo oS ee SS +315 miles TTA = ts ro Vertical Scale 20.000 Feet to an inch 10 T. W. E. DAVID. As already stated by Mr. Maitland, the faults bounding the Collie Coal-field’ are probably continuous with those which have given origin to the Stirling Range.’ Mr. Mait- land states in regard to the Stirling Range that lateral compression has worked from the south, and has formed three anticlines in a distance of ten miles. Mount Tool- brunup, the highest point in the range is nearly 4,000 feet above sea level. A prolongation of these faults to the H.S.H. runs through Cape Riche. The southern of these two faults, or perhaps zone of faults, has a throw of approxi- mately the order of 2,000 feet. In regard to the rift valley of the west coast, the sharp trend northwards of the Murchison River close to its mouth, and the remarkable coastal indents near Shark Bay are very suggestive of a prolongation of this rift valley in that direction. The probable geological structure of this rift valley are shown on Figs. 1 and 2, and that of the Collie- Stirling fault zone on Fig. 3. Fic 3. Diacrammaric Secrions Across CoLur-STIRLING TROUGH Vertical Scale 8000 feet to an inch M‘ Toolbrunup. 3341* STIRLING Collie Coal Field Fault Looking W.N.W Fault an GNEISSIC GRANITES eS ) 4 \ CNEISSIC & \ SCARY ves _CRANITE In addition to the evidence of the faults, the trend lines of West Australia are indicated by :— (1) Prevalent strikes of folds in sedimentary rocks. (2) The trend of the metalliferous (especially auriferous) belts. (3) The direction of the foliation and schistose structure in the gneisses and schists. (4) The trend of the banded jaspers and hornstones. 1 Permo-Carboniferous. * Older Palzozoie. PRESIDENTIAL ADDRESS. 1 | (5) The prevalent strike of the long axes of masses of eruptive rocks such as granite, quartz-porphyry, diabase, dolerite, etc. (6) Prevalent strike of quartz reefs. (7) Trend of joints in rocks. (8) Trend of rivers and lakes. The banded jaspers and hornstones are such a conspicu- ous feature in the geology of West Australia, and so wonder- fully persistent for distances of hundreds of miles, that they deserve special mention here. At Northampton in West Australia, there is a great development of what Mr. Maitland has termed sheeted zones of micaceous and garnetiferous granulite, traversed by much puckered and contorted veins of quartz. °“‘These sheeted zones trend generally north-west and south-east. These are not planes of bedding, but they represent gliding planes, along which the rocks have yielded to the irresis- table lateral pressure, resulting, inter alia, from the con- traction of the earth’s crust. The result of this lateral earth creep is that many of the rocks have been milled down, as it were, and in some cases rocks having all the external characters of finely banded slates or schist have resulted. An excellent instance of this occurs in the valley of the Helena River where the normal granite as a result of the operations of the great earth mill has been ground to powder or rock flour, producing a rock termed mylonite.”’ That the mylonites represented by the banded red jaspers and hornstones have been subject to earth movements since their formation is proved by the fact mentioned by Mr. Maitland, that at Bovgardie and on the Murchison field, as well as at Tuckanadra, 26 miles N.H. of Cue, they have been thrown into a series of gentle curves. They are crossed by numerous faults almost at right angles, and pockets of gold ore occur at the intersection. 12 T. W. E. DAVID. As regards prevalent strikes of folds in the sedimentary rocks and schistose structure in the gneisses and schists at the Porongorup Range near Albany, the massive gneisses are foliated in a direction N.W.toS.E. This trend is fairly constant amongst the older crystalline rocks of the southern part of West Australia, The three anticlines of the Stirling Range strike approximately parallel to the major faults which bound that range, the general trend being from W.N.W. to H.S.H. Mr. Maitland considers that the folding force has in this case operated from the south northwards. Further north, as in the Coolgardie and Kalgoorlie gold- fields, the strike of the foliation and bedding is more meridional being about N.N.W. and S.S.H. At Northam the trend of gneissic foliation is N.W. to S.E., while that of the quartz-dolerite or quartz-diabase dykes is chiefly from 8.W. to N.&. From the Murchison through Cue to Leonora, the trend lines in the older rocks are still a little W. of N. and H. of S. The same remark applies to the great auriferous belts. According to Mr. Maitland’s views, these consist of highly inclined metamorphic and sedimentary rocks associated with contemporaneous interbedded eruptive rocks. Some of these are distinctly amygdaloidal, and there is every reason to believe them to be ancient lava flows. These, in Mr. Maitland’s opinion, have been infolded in great synclines, amongst the gneisses, and have been subsequently intruded by newer rocks such as serpentines, quartz- dolerites (quartz-diabase), acid-porphyries, and granites, the last intersected still later hy greenstone dykes. According to Mr. Maitland’s view the great gold belts of Western Australia would therefore present some such an appearance as is shown diagrammatically on Fig. 4. The other alternative seems to be to regard these belts as overthrust, rather than as overfolded areas. There can be PRESIDENTIAL ADDRESS. 13 little doubt that both overfolding and overthrusting are present. Fic. 4. Sketch roughly diagrammatic from Perth to Kalgoorlie. ae Dee se Rv alictis of A. Gibb Maitland, FG GS ----- = =~ NS = = 7 N pod a aa os = / - t \ i \ b i : Me ‘ ) = Southern Cross - Perth DARLING RANGE 1” PENEPLAIN SS Te" > ¥ m sia a YE X i = EG <0 \y ; 3 AY AN | y \fexessieare SNEISS § OF vr . — reas ajo As the Pilbara region is approached, all the trend lines, as shown on Plate 2, swing from the nearly meridional once more intoa N.W. and §8.H. direction. This trend is well shown in the directions of the Ashburton, Fortescue, and De Grey Rivers, as well as in the trend of ranges like the Hammerley Range and the Throssell Range. The Doolena Gorge, “‘the gateway of the north-west,’’ and the Bangemall Anticline both have a N.W. to 8.f. trend. The 8.W. limb of this large anticline is steeper than the N.H. line, which suggests that the overfolding in this case came from the N.E. The fold * pitches’ to the S.H., which suggests that the earth-movement was more intense towards the N.W. At Warrawoona the newer dolerite dykes intersect the older folded rocks in enormous numbers. Their dominant strike is from S.W. to N.E., as in the case of the Northam dykes. In the Kimberley district of West Australia, Mr. H. T. Hardman’ has described Pre-Cambrian, Cambrian, Devonian and Carboniferous Rocks. Mr. H. P. Woodward’ has also described part of this area, as well as Dr. R. L. Jack, LL.D., F.G.S.° Their observations show that the schists, gneisses, * Report on the Geology of the Kimberley District, by E. T. Hardman By authority, Perth, 1884. 2 Report on the Gold-fields of the Kimberley District, by H. P. Wood- ward. By authority, Perth, 1891. 3 Bull. Geol. Survey, West Australia, No. 25, pp. 1-46. 14 T. W. E. DAVID. and banded jaspers strike in a N.W. direction through the King Leopold Range to King’s Sound. This belt of meta- morphic rocks is 10 to 30 miles wide and 120 miles in length. The Devonian rocks in the central and eastern part of the Kimberley region have been folded in broad open folds on axes which trend in a N. EH. and S. W. direction. The Carboniferous (Permo-Carboniferous Rocks) have not been folded, but merely tilted. In regard to the Devonian rocks of the Kimberley district Mr. Hardman estimated their thickness at nearly 11,000 feet, and Mr. H. P. Woodward describes these Devonian rocks as striking N.EK. and 8.W. The question that obvi- ously here suggests itself, is do these fold troughs of the central and eastern part of Kimberley, such as those of the Carr-Boyd Ranges, Saw Ranges and Lubbock Range meet Pre-Cambrian folds of the King Leopold Range in linking or insyntaxis. These trend lines from 8.W. to N.H. agree in general direction with the folding of the Devonian Rocks of the Burdekin district as well as with one of the two directions of folding on the Gilbert Gold-field of Queensland. From a letter received from Mr. Gibb Maitland it would appear probable that these two directions of folding at Kimberley in West Australia form part of a syntactic are, and they may therefore provisionally be grouped as such. At present the evidence as to the folds being symmetrical or asymmetrical in this region is insufficient. One cannot therefore as yet arrive at a definite conclusion as to the sense in which the folding force has operated. That we know so much already about the structure lines of West Australia, more probably than we know about those of any of the other States of the Commonwealth, is due chiefly to the enthusiastic and sustained efforts of Mr. A. Gibb Maitland and his colleagues, notably Mr. H. P. Woodward, Mr. EK. T. Hardman and others who have toiled PRESIDENTIAL ADDRESS. 15 so hard and so long ina country where travel bristles with dangers and difficulties. If now we turn to South Australia we find that most interesting features have lately come to light. The early report by A. R. C. Selwyn’ revealed a rough plan of the build of the Mount Lofty Ranges. The numerous records and reports by Mr. H. Y. L. Brown, Assoc. z.8.m.,? contain much information as to trend lines at intervals over this vast territory, and still more important information is afforded by his geological map of South Australia. The Horn Exploring Expedition to Central Australia elucidated the chief tectonic features of the MacDonnell Ranges.’ Mr. H. Basedow has published useful information as to the trend lines of the Musgrave, Mann, Everard, and Ayers Ranges.’ Dr. W. G. Woolnough’ has contributed a paper, chiefly petrological, on the Mount Lofty Ranges. Dr. Douglas Mawson, Bz, D.sc.,° has dealt with the structure of the north-eastern virgation of the Mount Lofty Range where it spreads away into the Barrier Ranges. Of late years a flood of light has been thrown on the obscure ques- tions of the trend lines of South Australia by Mr. Walter Howchin.’ e 1 Geological Notes of a Journey in South Australia from Cape Jervis to Mount Serle. Parl. Paper No. 20, Adelaide, 1859. 2 Chiefly on the mining fields of South Australia and Northern Terri- tory, published by the Mines Department of South Australia or as Parliamentary Papers. 3 Horn Scientific Expedition to Central Australia. Report on the Geology by Professor T'ate and J. A. Watt, m.a., B.sc. 4+ Trans. and Proc. Roy. Soc. 8.A., Vol. xx1x, pp. 57 — 102, pls. xiii — xx. > Trans. and Proc. Roy. Soc. 8.A., Vol. xxx11, pp. 121 - 137, pls. i, ii. 6 Thesis for D.Sc. Degree presented to the University of Adelaide, 1909-10. 7 Trans. and Proc. Roy. Soc. S.A., Vol. xxvi11, (1904), pp. 258 — 280. pls. xxxvii-xliv; Ibid., Vol. xxx, (1906) p. 227. Rep. Austr. Ass. Adv, Sci., Vol. x1, p. 114. The Geography of South Australia including the Northern Territory, by Walter Howchin, F.a.s., and Professor J. W. Gregory, D.sc. RS. Q.J.G.S., Vol. uxiv, 1908 pp. 234-258, by Walter Hewchin. 16 T. W. E. DAVID. In his introduction to Mr. Howchin’s Geography of South Australia, Professor Gregory contends that (op. cit., p. 25 26, fig. 6) there is evidence of two distinct groups of folds in South Australia, differing in date of birth as well as in direction. The older group has dominant H. and W. trends, the newer according to Gregory, have a nearly meridional trend inclining slightly to W. of N. His conclusions are evidently based on the observations of Mr. Howchin (op. cit., pp. 77-92). This very important problem will be discussed presently. Reference to the relief map, re South Australia, makes it clear that the most conspicuous tectonic feature is that of the depressed area in which lie Lakes Hyre and Torrens - prolonged southwards into the subsidence regions of Spencer’s Gulf and St. Vincent’s Gulf, and bounded east- wards by the western escarpment of the Mount Lofty and Flinders Ranges. Westwards the depressed area is bounded by the eastern edge of the great plateau of Central Aus- tralia near the west shores of Lake Torrens. If we refer to the map on Plate 2, commencing at Kangaroo Island and trace the lines of fold northwards, we cannot fail to be struck with the evidence of either a gradual change in the trend of the fold lines, or of the existence of two different groups of folds as argued by Mr. Howchin and Professor Gregory. The geological map is strongly in favour of a virgation and general meeting of the trend lines in syntactic arcs from Kangaroo Island to the Mount Lofty Ranges, and from the Mount Lofty Ranges to the Barrier Ranges. Dr. Woolnough in the paper just quoted, argues that the crystalline rocks on the eastern side of the Mount Loity Ranges represent folded Pre-Cambrian rocks, the trend of whose folds agrees approximately with the later folds of the Cambrian strata. Mr. Howchin on the other hand holds that these crystalline rocks of the eastern Mount PRESIDENTIAL ADDRESS. 17 Lofty Ranges represent Cambrian strata which have experienced intense contact metamorphism as the result of the intrusion of large contiguous belts of granite. Mr. Howchin, at the same time, has recorded the exist- ence of Pre-Cambrian rocks in the neighbourhood of Aldgate in the Mount Lofty Ranges, where their general trend lines, as far as they can be seen, correspond with those of the overlying Cambrian rocks. Certainly the Cambrian cleavages and joint planes pass directly downwards into those of the Pre-Cambrian. Mr. W.N. Benson, 8.sc.* states (op. cit., p. 107) that ‘‘in each of the three periods of great earth-movements evi- denced in the Mount Lofty Ranges, viz. (1) the Pre- Cambrian, (2) the older Paleeozoic Post-Cambrian, (3) the late Tertiary, the axis of folding or faulting was almost a meridional one. From Yankalilla to Aldgate, in the southern part of the Mount Lofty Ranges there appears to be an approximate agreement in direction between the Pre- Cambrian and older Paleozoic Post Cambrian folding. At the same time it is generally admitted that there is a strong unconformity between these two groups of rocks.”’ Again in Yorke Peninsula, near the Parara Mine, west of Ardrossan, Mr. Otto Tepper® shows that there is no great divergence between the strike of foliation there of the schists of Pre-Cambrian age and that of the Lower Cambrian limestone. He gives the strike of these Pre- Cambrian strata as N. 5° W.,’ at the Parara Mine, and N. 8° KH. at Mooloowurtie, the dip of the foliation at the Parara + Trans. Roy. Soc. S. Australia, Vol. xxx1u, 1909, Petrographical Notes on Certain Pre-Cambrian rocks of the Mount Lofty Ranges, with special reference to the Geology of the Houghton District, pp. 101 - 140, pls. i-v. 7 Trans. Phil. Soc. Adelaide, 1877-8, pp. 71-79, Cliffs and Rocks at Ardrossan, Yorke Peninsula. * The bearings given from here to the end of the paper are magnetic, except in the case of the bearings relating to West Australian areas. The latter bearings are true. B—May 3, 1911. Mine he gives as from about 60° to 70° easterly. The lower Cambrian rocks when traced northwards from Mount Lofty and eastwards into the Barrier Range district of New South Wales show, near Poolamacca a strike of N. 10° W. (magnetic) to N. 20° W., has been observed by me at Campbell’s Oreek in that vicinity, the dip being easterly at about 70°. At Torrowangie the lower Cambrian limestone (probable equivalent of the Brighton limestone near Adel- aide) dips E. 15°.N. at about 13° upto 20°. At Paps Oreek about 32 miles northerly from Broken Hill, near the locality of Campbell’s Creek above referred to, Dr. Mawson has observed an unconformable junction between the lower Cambrian system and a group of schists (talc and mica schists) immediately to their west. There can be little doubt that these schists are Pre-Cambrian. : 18 T. W. E. DAVID. The authors of the geology of the Broken Hill lode’ point out that there is a divergence of strike between that of the schists and that of the Cambrian strata at Paps Oreek of from 25° to 33°. These tale or mica schists although Pre-Cambrian may not be Archzean. Now at Broken Hill, only 32 miles to the south, the true Archzean gneiss and ~ amphibolite schists strike about H. 40° N., and have been strongly overfolded as well as overthrust ina south easterly direction. There is thus a wide divergence between the trend of the folia of these Archeean rocks of Broken Hill and the strike of the lower Cambrian glacial beds and lime- stones near Campbell’s Creek and Torrowangie, the diver- gence amounting in this case to about 60°. But there is also a divergence between the trend of the Broken Hill Archezeans and that of the Paps Creek schists. Possibly the latter may be Algonkian, for which age in the Mount Lofty region Dr. Woolnough has proposed the term Barossian. + Australasian Inst. Mining Engineers, Vol. v1, No. 11, April 1910, by Messrs. R. J. Donaldson, C. W. Matters, R. T. Slee, J. C. Coldham, H. H. Walman, F. Voss Smith, and H. W. Davies. PRESIDENTIAL ADDRESS. 19 There probably seems evidence in the Broken Hill region for a considerable divergence between the strike of the Archean gneiss and that of the lower Cambrian rocks. This Broken Hill evidence suggests that Mr. Howchin’s conclusions as to the difference in strike of the Pre-Cam- brian mountains of South Australia and the Cambrian may be reconciled with the apparent conformity of the two directions of strike in the Mount Lofty Ranges on the assumption that in the Pre-Cambrian complex there are at least two distinct groups, (1) an Archean group chiefly formed of gneiss and other coarsely crystalline rocks, (2) an Algonkian (or Barossian) group, and that the folding of group (1) took place much earlier than that of group (2) and was divergent in direction from it. It may also be assumed that group (2) was heavily folded before the depos- ition of the lower Cambrian beds, so as to leave a consider- able unconformity between it and the Cambrian system, but that the direction of folding was less divergent from that of the Cambrian than it was from that of the Archeean. Mr. Howchin concludes that there is strong evidence of the divergence of the Archean folds of what he terms the Willouran and Babbage line, and those of the Cambrian in the region between Lake Torrens and Lake Eyre. The other alternative is to assume that both Algonkian and Archean rocks have been folded on similar trend lines, which mostly diverge from the later trend lines of the Cambrian, though in places they coincide. On the whole it may be said that in the neighbourhood of Spencer’s Gulf, St. Vincent’s Gulf and the Mount Lofty Ranges the divergence between the trend lines of the Barossian group and the Yorke Peninsula group on the one hand and those of the Cambrian on the other, do not appear to be very strongly marked. On the other hand there is strong evidence of (1) aspiral structure, and (2) of virgation. 20 T. W. E. DAVID. The great spiral commences in Kangaroo Island where an east and west trend swings gradually into a N. by E. to N.N.E. direction through the Mount Lofty Ranges, with a fine series of overfolds directed towards the west. As the Barrier Ranges are approached, the trend lines virgate striking about H.N.H. (true) near Broken Hill. There the folds are overturned and the fault planes overthrust towards the 8.S.H. Thus the ‘sense’ of the folding changes in the country which intervenes between the Mount Lofty Ranges and the Barrier Ranges. Mr. Howchin has shown that in the region which lies between the Barrier Ranges and Lake Torrens, the Flinders Ranges are not folded asymmetrically. Mr. Howchin' has shown that in the northern section of the Flinders region the trend lines, near Beltana, strike N.W. Mr. H. Basedow also states’ (p. 81) that the Cambrian strata near the head (northern end) of Lake Torrens appear to strike from N. 25° W. round to W. This suggests that the old trend lines of the western part of the great virgation are swinging round to meet the trend lines of the Musgrave Ranges. These ranges described by Gosse,’ 1873, and by H. Y. L. Brown* and V. Streich’ have also been examined and reported upon by Mr. H. Basedow,’ who shows that these Pre-Cambrian ranges formed of gneiss, schist, granite, quartzite etc., have a dominant strike nearly EH. and W. At Opparinna Spring he figures a strong overfold directed . to the north. Inthe Kelly Hills the schists strike about 1 The Geography of South Australia, Whitcombe and Tombs, 1909, p. 90. 2 Trans. and Proc. Roy. Soc. 8.A., Vol. xx1x, 1905, Geol. Rep. on the country traversed by the S.A. Gov. N.W. Prospecting Exp. 1903, pp. 57 — 108, pls, xili - xx. 5 Gosse, Central and Western Exploring Expedition. By authority, Adelaide, 1873. + Rep. Journey from Warrina to Musgrave Ranges, p. 2, Adelaide. By authority, 1889. 5 Sci. Results Elder Expi. Exp., Trans. and Proc. Roy. Soe. 8. > Vol. XVI, pp. 77 and 83. PRESIDENTIAL ADDRESS. 91 N.N.E. (true), dipping at 40° to E. 21°S. (true). Mount Woodroffe, 5,200 feet high, in these ranges is perhaps the highest peak inSouth Australia. Beyond the western end of the Musgraves rise the Mann and Tomkinson Ranges. The Mann Ranges, also formed mostly of Pre-Cambrian rocks, exhibit planes of foliation and schistosity trending from between N.H. and S.W., to W. by N. and E.byS. The folding as shewn by Basedow (op. cit., p. 62 and PI. xix) is intense but not very asymmetrical. As far as can be judged from his figure there is a slight tendency for the folds to be forced over towards the north. The Tomkinson Ranges, formed of Pre-Cambrian gneisses and schists, also have large intrusive dykes of olivine- gabbro and norite. The gabbro intrusions trend about H. and W. Diorite dykes follow the same trend. The planes oi foliation of the gneisses trend north-easterly (Basedow, op. cit., p. 75). In Ayers Range the gneissic folds have a general trend a little S. of W. and H. of N. At Mount Conner there is a great unconformity between the Ordovician quartzites and the Pre-Cambrian crystalline group. The strike of the quartzite varies from W. up to W. 30° N. (magnetic). Mounts Kingston, Olga, and Ayers Rock are formed respectively of quartzite, conglomerate and metamorphic grit, considered by Tate and Watt to lie at the base of the Ordovician Series.' The Levi Ranges to the south of the MacDonnell Ranges are also formed of Ordovician rocks and folded according to the same authors On approximately EK. and W. axes. The folds appear to be nearly symmetrical. In the MacDonnell Ranges the same authors show that the Pre-Cambrian gneisses, schists, and quartzites of that region are very strongly folded, and that the trend in the central and eastern part of the MacDonnells is nearly H. 1 Rep. Horn Exp. Centr. Austr., General Geology, p. 59. 22 , T. W. E. DAVID. and W., whereas westwards the folds bend somewhat to W. of N. inclining eventually to W.N.W. As far as can be judged from the sections supplied by these authors, there is a slight overfolding from N. to S. As regards newer structure lines it seems probable from the steepness of the southern escarpment of the Mac- Donnells and its narrow rocky canons, such as those of Redbank Gorge, and the gorge of the Finke River, that there has been comparatively recent movement along an old E. and W. fault plane. The most important of these newer tectonic lines, as has been indicated by Mr. Howcbin,* Prof. Gregory,’ and Mr. W. N. Benson, B.sc.,’ are the series of important and comparatively recent zones of fractures which run more or less meridionally between the western scarps of the Mount Lofty Ranges and the high western plateau bounding Lake Torrens on the west. In this fractured and foundered area, termed by Professor Gregory the ‘ Rift Valley of Australia,’ lie St. Vincent and Spencer Gulfs, Lake Torrens, Lake Hyre etc., the last mentioned at its centre being about sixty feet below sea level. This region appears to have been an area of subsidence from very early time. Even the lower Cambrian strata of Mount Lofty crept westwards in their effort to fill up this senkungsfeld; and in his latest paper Mr. Howchin has shown that even the Miocene strata to the south of Adelaide have been overfolded in the same direction. The earthquake which visited the Adelaide region on September 19th, 1902, appears to have had its epicentre near Warooka towards the southern end of Yorke Peninsula. This proves that movement of the earth’s crust along this important zone is still in progress. The accompanying 1 Q.J.G.S., Vol. uxiv, p. 234-268, pls. xxvi—xxix. Geography of S. Australia, pp. 88, 89 and 100; and Trans. Roy. S. S.A., Vol. xxvuir, 1904, pp. 258 - 280, pls. xxxvii - xliv, and ibid. Vol. xxx, 106, pp. 227 — 262; pl. x1. 2 Dead Heart of Australia. 5 Trans, Roy, Soc. S.A., Vol. xxx111, 1909, pp. 106-7, and ibid. 1910. “ie PRESIDENTIAL ADDRESS. 23 section, Fig. 5, after Howchin, shows the probable struc- ture of this senkungsfeld. . Fic 5. SkeTcH SECTION. (Suggested by works of Walter Howchin) Across THE RiFT VALLEY OF SOUTH AUSTRALIA sdk Vertical Scate 10,000 feet to an inch. MW Lofty 20 5 St VINCENT 1000% PortLincoIn spENCERS GULF VenGlaeniebe re 4008 TERTIARY , PERMO-CARBONIFEROUS AND CAMBRIAN ROCKS IN TROUGH FAULT FAULT We may now glance briefly at the trend lines of Northern Territory, as far as they are known. The Rev. J. H. Tenison-Woods’ figures a highly folded series of crystalline rocks without giving the trends of the folds. Mr. H. Y. L. Brown’ in several reports has, with his assistants, placed us in possession of our present information as to the dominant structure lines of that region. The following conclusions may be provisionally drawn from Mr. Brown’s reports :— (1) That the Pre-Cambrian schists and gneisses have been folded on lines whose directions vary from N. and S. to N.N.W. and 8.8.H. (2) That the lower Cambrian Salterella limestones and associated strata strike about N.W. and S.EH. with lines of major faulting and zones of crushing trending in the same direction. (3) That the Ordovician quartzites have been somewhat folded and strongly tilted, the chief direction of the tilt being towards a little W. of S. This tilting appears to be connected with the great tectonic lines which extend through New Guinea in an H. by S. and W. by N. direction. (4) That the Permo-Carboniferous rocks have not been folded. * Report on the Geology and Mineralogy of Northern Territory. By authority, Adelaide, 1886. ? Northern Territory Exploration, 1895. Northern Territory of S.A., Report by H. Y. L. Brown. By authority Adelaide, 1905. 7" | (5) That recently hot springs, such as those of the Douglas River have broken out along lines which trend between N. 35 W. and N.W. | We thus see in the Northern Territory evidence first of a N. by W. foliation of the Pre-Cambrian rocks, followed by a N.W. folding of the Cambrian strata, and this in turn succeeded by a general tilting of all the strata from Ore- taceous downwards in aS. by W. direction, showing that this part of Australia has probably of late fallen under the control of the New Guinea lines of uplift. Much informa- tion on the subject of the tectonic lines of Northern Territory may be expected from Dr. W. G. Woolnough on his return from the Scientific Exploring Expedition in Northern Territory. We may now turn to the south eastern part of Australia, and review the tectonic lines of Tasmania, Victoria, and New South Wales. 24 y T. W. E. DAVID. Tasmania.—Mr. W. H. Twelvetrees, F.G.Ss.,, and Mr. T. Stephens, M.A.,” and Mr. R. M. Johnston, F.G.s.,* have devoted some attention to the dominant trend lines. Mr. Twelvetrees has shown that on the west coast of Tasmania the schists of Pre-Cambrian age strike about N. 20° W., at the Rocky River on the Waratah Corinna Road, and at Cox’s Bight on the south coast Pre-Cambrian (Algonkian) biotite schists and quartzite strike N.N.W. to N.W. They dip at low angles to the S.W. Mr. Twelvetrees estimates a minimum thickness for these beds of about 13,000 feet. On the N.W. coast at Rocky Cape quartzites and quartz- schists (Algonkian) trend N. and §., or a little W. of N., and H. of S. At the Forth River micaceous schists, horn- blendic schists with garnet and zoisite, and quartzites strike W. of N. with a westerly dip. » Rep. Austr. Assoc. for Adv. of Sci., Vol. x1, 1907, pp. 4066 - 470, and ibid., Vol. x, 1904, pp. 613 and 622 — 630. # Proc. Linn. Soc. N. S. Wales, Vol. xxx111, pt. iv, pp. 752— 767, pls. XXIV — XXVili. $’ Geology of Tasmania, by R. M. Johnston, F.c.s., etc. By authority, Hobart, 1888. PRESIDENTIAL ADDRESS. 25 Infolded amongst these Algonkian rocks are strata of Cambrian, Ordovician and Silurian Age thrown into long folds approximately parallel to the older trend lines of the Pre-Cambrian rocks. These strongly marked N.N.W. and S.8.E. trend lines of the western side of Tasmania are crossed by a line of granite intrusion which may be termed the Waratah axis, as it runs through the Mount Bischoff Mine at Waratah; this trends about N.H. and S.W. On the east coast the long meridional line of granite intrusions extending from the Hippolyte Rocks on the S., through Maria and Schouten Islands, Freycinet’s Peninsula, St. Patrick’s Head, St. Helens and Cape Barren Island and Flinders Island, marks a strong N. and 8S. tectonic line. In the V formed by these two dominant trend lines is enclosed the Permo-Carboniferous and Trias-Jura basin with their massive sills of quartz-dolerite or quartz-diabase. Mr. Twelvetrees has shown that the alkaline rocks of the Port Cygnet district have broken out along a line trending S. 40° W., and that the distribution of the melilite basalts of Tasmania indicate an eruptive line trending about H. and W., near Lake Sorrell, and about H. 10° N. near Hobart between Rokeby and One Tree Point. The geological faults of Tasmania have not yet been worked out. Mr. Montgomery’ records minor faults with throws of about 200 feet at Beaconsfield to the north of Launceston. Mr. B.C. Andrews’ has enumerated some probable lines of heavy fault as indicated by physiographic evidence, as follows:—Ben Lomond, Western Tiers, Mounts Roland and Wellington, north-east coast and east coast. R. M. John- ston’ has already figured, on direct stratigraphic evidence several important faults on the south side of Mount Well- ington. The line of melilite basalt eruption already 1 Rep. Austr. Assoc. for Adv. of Sci., Hobart, Vol. 1v, pp. 321 — 327. ? This Society’s Journal, Vol. xtiv, 1910, p. 477. ° Geology of Tasmania, p. 163, see section opposite page. 26 T. W. E. DAVID. mentioned trending about H. 10° N., probably marksa fault along this line. The great scarp to the west of Oradle Mountain, 5,069 feet high, the highest point in Tasmania, probably marks a line of major faulting witha heavy throw to the west. Atthe same time the existence of the great resistent sills of quartz-dolerite thrust over the thick masses of soft sediment of the Trias-Jura and Permo-Carboniferous systems afford exceptionally favourable conditions in this part of the island for the formation of steep scarps by sap- ping, unassisted by faulting. A prolongation of this hypo- thetical line of faulting to the west of Cradle Mountain trends towards Hobson’s Bay, in Victoria. Another possible dislocation line in Tasmania is the gap through which the railway line from Launceston to Hobart passes between Ross and Oatlands. There can be little doubt but that in Tasmania block-faulting has assisted sapping in producing the steep scarps of the ‘tiers,’ that inland plateau so much of which is over 4,000 feet above sea-level, with peaks such as Mount Wellington 4,400 feet, Mount Field (or Humboldt) 4,721 feet, Ironstone Mountain 4,736 feet, and Cradle Mountain 5,069 feet above sea-level. Victoria.—A glance at Plate 2 at once reveals the important fact that there are at least two widely divergent trend lines in Victoria. First there is the obvious trend of the Main Divide of Victoria from H. to W. Then there are the older lines having a nearly meridional trend, which mark the position of the Grampians, Howitt-Wellington mountains, Snowy River porphyries, and the deep valleys of the Kiewa and Mitta-Mitta Rivers, the former sunk some 4,000 feet below the summit of the Bogong Mountain. The geological map of Victoria shows that trending sympathetically with the Main Divide is the belt of Trias- Jura sandstone of the Wannon, Otway, and Gippsland areas. Between the last two regions lies the great valley of Victoria." * The Geography of Victoria, by Prof. J. W. Gregory, D.8., F.R.S., p. 77 PRSIDENTIAL ADDRESS. 2k The central and western parts of this great valley are occupied by the basaltic lavas mapped on the sheets of the Victorian Geological Survey and recently described in detail by Professor H. W. Skeats.' This east to west sag of the trough of the “‘ great valley ’’ has led to the isolation of the Wannon Trias-Jura area from that of the Otway area, as the result of the inflow of the sea and deposition of Marine sediments over this part of the basin in Tertiary time. The isolation has been further completed still later by the outflow of vast sheets of basaltic lava. Dr. T.S. Hall’ has emphasised the isolation of the Otway region as the result of this subsidence along the great valley in his chapter ““ The Otways as an island.’”’ Mr. Reginald A. F. Murray’ has given a brief account of the metamorphic rocks and crystalline schists of Victoria and their trend - lines, as well as of those of the older Palseozoic rocks. He remarks that (op. cit., p. 34) ‘‘The leading characteristics of the Lower Palzeozoic rocks of Victoria are the normal N. Westly to N.N. Hasterly strike, and the high rate of inclination of their bands caused by the crumpling or fold- ing process to which they were subjected at a period not long subsequent to their deposition etc.”’ According to R. A. F. Murray, following A. R. C. Selwyn, Victoria as regards its older rocks and the lines of folding in older and newer Palzeozoic time is a vast syncline extend- ing from the crystalline schists of the Wannon and Glenelg Rivers on the west to the similar rocks of the Mitta-Mitta massif, or Benambra Highland on the east (op. cit., pp. 37, —78). Professor Skeats figures as Archean‘ (op. cit., p. 231) the foundation rocks between the Hummocks and the 1 Rep. Aust. Assoc. Adv. of Sci., Brisbane, 1909, pp. 173 — 229, pls. 1— iv. 2 Victorian Hill and Dale, by T. S. Hall, w.a., psc, Melbourne, T. C. Lothian, 1909, pp. 99 — 106. 5 Victoria, Geology and Physical Ceoetapue! By authority, Melbourne 1887, pp. 36, 37. * Rep. Austr. Assoc. Adv. of Sci. Brisbane, 1909, pl. i, p. 280. 28 T. W. E. DAVID. Mount Stavely Range. This geosyncline between Benambra and the Glenelg River is warped across in a direction trend- ing from about N. and &., or a little H. of N. and W. of S. by ancient axes or hinges of folding referred to by Professor Gregory as the line of the Colbinabbin Range.’ On the latest geological survey map of Victoria this area is coloured *‘ Heathcotian,’ and referred with a query to the Cambrian. Sections across this supposed Cambrian axis have been published by Professor Gregory.” In section 7 (op. cit.) he shows a parallel axis to the Colbinabbin axis at Dookie. On the other hand Professor Skeats in his able and well illustrated paper marks with a query as basal Ordovician the diabase series of the Knowsley district N. of Heathcote. In any case all the Victorian geologists seem agreed that there is an old axial line of folding run- ning approximately meridionally through Heathcote. On either side of this Colbinabbin axis lie troughs of Ordovician rocks. These have been folded very strongly as shown by Mr. E. J. Dunn,’ on lines about N. 25° W. (true) and H.ofS. The folds near Bendigo (Sandhurst) are some- what asymmetrical, the source of the thrust being to the H., so that the folds are overturned towards the W. So much have these Ordovician strata been compressed that for considerable distances they now occupy only one half of their original dimensions measured along H. and W. direc- tions. Professor Gregory shows four troughs of Silurian rocks* infolded in the eastern Ordovician syncline between Keilor and Mount Wellington. A glance at the geological map of Victoria shows that the Snowy River porphyries of Lower Devonian (?) time were developed along a line of eruption approximately meridional,andthe middle Devonian + The Geography of Victoria, p. 69, 70. * Proc. Roy. Soc. Victoria, 1902, pl. xxv. * Report on the Bendigo Goldfield. By authority, Melbourne, 1896. * Proc. Roy. Soc. Vict., 1902, pl. xxv, section 5. . PRESIDENTIAL ADDRESS. 29 Buchan and Bindi limestones lie in troughs also approxi- mately meridional. A very strongly marked trough is that in which lie the so called (on the geological map) Devonian, by others considered Carboniferous, rocks of the Mitchell, Avon, and Macallister River regions. These strata con- tain in places Lepidodendron australe. They mark a strong N.N.W. to S.S.H. trend line from Mount Wellington 5,363 feet to Mount Howitt and beyond. A good section across this area is given by Professor Skeats.’ To the W. of the Macallister River a strong fault is marked having a trend presumably about N.N.W. and S.S.E. The upper Palzeozoic rocks of the Mount Wellington and Macallister are shown dipping off an axis of intrusive serpentine. With these late Devonian or early Carboniferous rocks folding in Victoria practically ceased. The Permo-Car- boniferous glacial beds are mostly either nearly horizontal or but gently inclined. But near Bacchus Marsh, as shown by Messrs. OC. O. Brittlebank and G. Sweet, F.G.s.,” they dip in a general southerly to south-easterly direction at angles of from 5° up to in places 45°. As the grooving on the rock surfaces and the carry of the erratics all points to the ice having moved from 8. to N., and the whole sur- face of the country was probably overridden by ice from at least as far as Bacchus Marsh on the south to Beechworth on the north, the present Main Divide could not then have existed, but the gathering ground of the snowfields must. have‘ been situated near to, or south of, the present southern coast of Victoria. The strong southerly dip of the Permo- Carboniferous glacial beds near Bacchus Marsh suggests that the warping up of the Main Divideof Victoria took place chiefly in very late Palzeozoic time, and was connected with the intrusions of the large batholiths of granite which lie 1 Rep. Austr. Assoc. for Adv. of Sci., Brisbane, 1909, pl. ii, fig. 2, p. 238. 2 Rep. Austr. Assoc. for Adv. of Sci., Adelaide, 1893. 30 T. W. E. DAVID. mostly a little north of the present Main Divide. At the same time the distribution of these granites between the Strathbogie Ranges and Cape Liptrap suggests that merid- ional trend directions were still operative though on the whole dominated by the H.andW.trends. That the warping was continued into Mesozoic time is proved by the tilting into broad basins of the Wannon, Otway, and Gippsland Trias-Jura strata with their associated coal seams. These HB. and W. lines, which may be termed Bassian lines (after Bass Strait), continued to develop during Tertiary and Post Tertiary time. EKocene marine strata along the axis of the Great Valley of Victoria have been raised fully 800 feet above sea level. As already stated, the line of major fault, which has given rise to the steep escarpment W. of Bacchus Marsh, appears to have originated in Tertiary time and developed along the Bassian lines as did the H. and W. fault near Sorrento on the southern side of Hobson’s Bay (Port Phillip). Nevertheless while the E. and W. warp lines dominated earth movement in Victoria in Mesozoic and Cainozoic times, evidence is not wanting to show that the forces which had produced the old N. and 8S. trend lines were not entirely in abeyance. Mr. Stanley Hunter’ has shown that the floors of the Tertiary rivers have been much warped, so that for some distances the drainage direction is reversed, so that streams once flowing south like those of Ballarat have now a rising instead of a falling gradient down stream, and moreover they show evidence that their eastern bends have been tilted up showing that the ranges to the east have been uplifted subsequent to the formation of the lead. He also records the fact that comparatively recent fault lines are occasionally met with in the alluvial workings for gold with displacements of about 30 feet, (op. cit., p. 5). This * Mem. Geol. Surv. Victoria, No.7, Deep Leads. By authority, Mel- bourne, 1909, p. 4. PRESIDENTIAL ADDRESS. 31 evidence agrees with that mentioned to me by Mr. — Mahony, B.sc., of the Geological Survey of Victoria that the recent dune rock near Sorrento is heavily faulted to the east of Sorrento in a N. and &. direction with a downthrow tothe W. This fault trends northwards through the gap in the range through which the Melbourne to Sydney rail- way line passes to the south of Seymour. The homoseismic lines for the earthquakes of May 10, 1897, and May 27, 1900, suggest that the older meridional lines and the newer Bassian lines are still being followed by earthquake cracks.’ The nature of the folding to which Victoria has been subjected is shown on fig. 6 a and b, and the trend lines are shown on Plate 2. SECTIONS across VICTORIA Fig.6(a). Main Divide Snowy River Connors Plain 3500" yrWellington — POrPhyries : Fault: ‘Faulr 5363 Ft (Lower Devonian) x Glenelg Grampians : an UpperDevoruan sy 149: Ordovician River Silurian Lae Terhary Tertiary Silucian' Tertiary : Epo ierous Basait o Basalt Wb Ny - Vi 9890035358 08 OR BEY IDE brian Schists’ 3 : gate Ges Sseo9 Granite - -- - - - -- --- -- ------450 miles; Granite - - - - - Serpéntine SSeS eae -> “porphyry Fig.6(b). Alkaline Lavas : Ss N. Heathcote Harcourt arjacedon Permo-Carboniferous Pr Nepean >» ee (Permo ae Silurian ‘Bass Strait ‘ Echuca Ordovician ‘Carb? salt: Port Phillip Bay - Recent ; Sora: “+ Melbourne Fault Tertiary : ; Nort Sea Tertiary ; oye, 3 Dune Rock wee ew ee ee ee = a ee i = KK ne Ke etn New South Wales.—The outlines of the chief tectonic features of this State were traced with a masterly hand by the Rev. W. B. Clarke, F.R.s.”>. The late Government Geologist, C. 8. Wilkinson, constructed a valuable map of " Geography of Victoria, by Professor Gregory, p. 175. * Southern Goldfields of New South Wales, and remarks on the Sedi- mentary Formations of New South Wales. Fourth edition 1878. 32 T. W. E. DAVID. the Hartley Bowenfels District which shows the folds of the Devonian rocks of that neighbourhood, and did much to elaborate the geological map outlined by Mr. Olarke. This has been added to under the direction of Mr. Wilkinson’s successor Mr. H. F. Pittman, Assoc. R.s.u., by himself and the officers of his Geological Survey, notably Mr. J. E. Carne, F.G.S.,and Mr. H. C. Andrews, B.A., while the maps of the Southern Coalfield by Messrs. J. B. Jaquet, Assoc.B.s.M., and L. F. Harper, F.G.S., and that of the Hunter River Coal- field by Messrs. G. A. Stonier, W. 8S. Dun, O. Tricket and myself have added information on tectonic movements of the crust since Permo-Carboniferous time. These obser- vations have been supplemented by the valuable work of Dr. H. I. Jensen, p.sc., on the alkaline rocks of the Canobolas, Warrumbungle and Nandewar Ranges.’ Messrs. O. A. _Stssmilch, EH. C. Andrews, and CO. Hedley, have lately con- tributed useful and suggestive papers on the physiography of New South Wales, references to which have already been given at the commencement of this address. Dr. W.G. Woolnough, D.sc.,” and Mr. F. G. Taylor, B.A., B.E., B.Sc.,” have also added to our knowledge of the physiography of this State. The physiographic method of study of earth tectonics is obviously of special value in New South Wales, where along the whole of its Main Divide and coastal area marine strata later than the Permo-Carboniferous are unknown. In New South Wales there are two chief lines of trend, the older trends, (the direction of which is well shown by the orientation of the trough axis of our main + Proc. Linn. Soc. N.S. Wales, 1909, Vol. xxxiv, pt. 1, by C. A. Stiss- milch, ¥.¢.s., and H. I. Jensen, psc. pp. 157-194; ibid. 1907, xx x11, pt. 3, by H. I. Jensen, pp. 557 - 626, 842 etc. Also for general reference to distribution and trend lines of these alkaline rocks of East Australia together with references, see ibid. 1908, Vol. xxx111, pt. 3, pp. 491 - 588, and particularly Fig. 10 on p. 585. ? Ibid., 1906, Voi. xxx1, pp. 546 - 554. * Commonwealth Bureau of Meteorology. Physiography of Proposed Federal Territory at Canberra, Bulletin No. 6, 1910, and ibid. Bull. No. 8. PRESIDENTIAL ADDRESS. 33 coal basin) running N.N.W. and §.S.E., inclining to a more meridional direction southwards towards Kosciusko, and newer trends running parallel or sub-parallel to the present Pacific Coast, and that trends N. by E. toS. by W. The latter trends are well shown by Mr. Andrews.’ The tectonic feature which is most Conspicuous in the geology of New South Wales is the great syncline, in which lies the Permo-Carboniferous coal-basin, the main axis of which extends from Sydney to Gunnedah and Narrabri. This divides at once the Bathurst-Monaro highlands, or tableland, from the New England tableland. In the former tableland the older trend lines are well shown by the direction of outcrop of the chief beds of limestone, of Silurian age, which there run N. and S$. ‘Towards the northern edge of this plateau these fold lines swing more to the W. of N., the chief synclinal troughs in the upper Devonian series lying along N.N.W. to N.30 W. directions. There is a strongly marked unconformity, recorded and figured by Dr. W.G. Woolnough in the gorge of the Shoalhaven near Tallong, between the Ordovician slates and the Silurian limestones. The folding of the Ordovician rocks has also been much more intense than those of the Silurian. In the Yass district the general trend of the folds in the Silurian and Lower Devonian rocks is about N. 15° W. and S. 15° E., as shown by Mr. Harper’ and myself.* The prevailing dip is to about W.15'S. At Yalwal Mr. Andrews has shown that the Upper Devonian rocks, lying in a long and narrow basin, trend nearly due N. 30° H. (true). If we examine the direction of strike of elongated masses of intrusive granite from Delegate on the 8S. to Bathurst on the N., we find that there is aslight tendency to virgation, the great mass + This Society’s Journal, Vol. xuiv, p. 347. ? Proc. Linn. Soc. N.S. Wales, 1909, Vol. xxxiv, pp. 783—5. * Geol. Surv. N.S. Wales, 1909, Vol. 1x, pt. 1, pp. 1 - 53. + Ann. Rep. Depart. Mines, 1882, p. 148, with maps and sections. C—May 3, 1911. 34 T. W. E. DAVID. of granite extending from Bombala to Braidwood runs N. 15° E.andS. 15° W., but the mass extending from the Snowy near Forest Hill to Adelong trends about N. 8° W. In the Forbes-Parkes Goldfield’ Mr. Andrews shows the trend of the Silurian folds to be N.N.H. with suggested overthrusts to the H.S.EH., an approximation to the Broken Hill trends in pressure directions. In the Cobar region Mr. Andrews finds the strike of the Silurian limestones and conglomerates and Devonian quartzites is generally about N.N.W., with several major faults apparently overthrusts striking in the same direction with the overthrusting being towards the west. Traced in the direction of Girilambone, the strike changes to N. and even N.H., the rocks there being schists and quartzites, possibly, as Mr. Andrews thinks at present, Pre-Cambrian. Possibly these latter rocks represent an offshoot from the Pre-Cambrian series of Broken Hill which have, as already stated, prevalent north-easterly trends. Mr. C. S. Wilkinson’ shows that the strike of the Devonian beds, W. of the Blue Mountains is N.N.W. and §.8.H., and Mr. J. E. Carne’s work confirms this. At the same time the strike of the Jenolan Cave Pentamerus limestone, in the Silurian rocks, is nearly N. and S. with a westerly dip. Mr. OC. A. Siissmilch’ and Dr. H. I. Jensen* have referred to the folded rocks of Silurian and Devonian age in the Canobolas region, and the former determines the strike of these folds as about N.30°W.(true). Near Ponto to the west of Wellington, a very strongly developed and intensely folded trough in the Devonian and Silurian rocks has lately come under my notice. If the + Depart. of Mines, Geol. Surv., Mineral Resources No. 18, by authority 1910. * Geological map of the districts of Hartley, Bowenfels, Wallerawang, and Rydal. S$ This Society’s Journal, Vol. xu, p. 180, 1906. * Proc. Linn. Soc. N. S. Wales, Vol. xxx1v, pt. 1, 1909, pp. 158 - 194. 7 PRESIDENTIAL ADDRESS. 35 strata are not repeated by isoclinal folding and faulting, nearly 10,000 feet of red sandstones and shales are there developed lying in a trough, the axis of which trends nearly N. and S. from a little W. of Wellington towards Molong. Mr. Stissmilch’ has already called attention to the strong disturbances of the nature of recent faulting, determined on physiographic evidence, extending from Jindabyne and Cooma, in the former case north-easterly, in the latter northerly. The Cooma-Colinton line of fractures is parallel to the upper course of the Murrumbidgee, that is about N. 5 W. Mr. T. G. Taylor has further examined the zone of faults between Lake George and the Murrum- bidgee River near the site of the Federal Capital at Canberra. In his latest work he refers to this Snowy- Murrumbidgee line of disturbances asa rift valley running northwards to the volcanic region of the Canobolas, and thence by way of Wellington to the volcanic zone of the Warrumbungle volcanic necks. These faults, described by Sussmilch and Taylor, are of course recent faults for the most part belonging to the present cycle of erosion, but they appear to be established along old lines of intense folding and major faulting. It is much to be desired that a reliable cross section of this beautiful tectonic region between Bathurst and Parkes be obtained by actual survey. An important fact to be noted in the Bathurst-Monaro tableland lying to the south of the great central coal-basin, is that along its north-eastern margin is an extensive belt of Devonian rocks which strike nearly conformably with the axis of the main trough of the great coalfield. One would expect to find the overfolds of the Devonian rocks directed bere towards the main axis of subsidence ; on the whole, though the dips are often reversed in the neighbour- hood of axes of intrusive masses of granite, the marginal ? This Society’s Journal, Vol. xLIII, pp. 331 - 354, pls. ix — xili. 7" Devonian rocks show a tilt towards the H.N.H., that is in the direction of the main basin. 36 T. W. E. DAVID. If now we examine the important unit of the New Hngland tableland, the following tectonic lines are obvious :—The long belt of serpentine recently described in detail to this Society by Mr. W.N. Benson. This extends for fully 150 miles from Nundle to Bingara, striking in a general N.N.W. and 8.S.H. direction. The Carboniferous and Devonian rocks have been folded and powerfully fractured along the same line, the pressure coming from H.N.H. from about KB. 17° N. (true). Further north in the Hmmaville district of New England, the Permo-Carboniferous, and perhaps Carboniferous claystones, are folded on lines trending about N. 30° W. and §. 30° E., with evidence of the pressure having come from H.30°N. The trend of the Permo-Carboniferous limestones near Kempsey is about N. 35° W. (true). On the other hand the great intrusive masses of granite which occupy so large a part of the country between Tamworth and Wallangarra on the Queensland border strike about _ N. 22° E. (true). This direction is almost exactly parallel with the coast line, and shows that in New South Wales as in Victoria, the axes along which the granites were intruded belong to the newer trend lines which determined the position and orientation of the present coast line. Mr. H. C. Andrews has shown that in the New Hngland district the granites have strongly intruded the Permo- Carboniferous rocks, whereas in the Lithgow district of the western coal-field rolled pebbles of the Hartley granite are very frequent in the basal upper marine Permo-Carbonifer- ous rocks of that area. The long axis of the Clarence Basin is exactly meridional (true), Another important tectonic line is the belt of alkaline lavas which form such conspicuous elevated and isolated groups on the relief model, Plate 1, extending from the extinct volcanoes of PRESIDENTIAL ADDRESS. 37 the Canobolas through those of the Warrumbungle moun- tains to those of the Nandewar Ranges. The trend of this great alkaline belt and its prolongation in Queensland through the Macpherson Range, Cunning- ham’s Gap, and the Glasshouse Mountains on to Yeppoon, near Rockhampton, and thence to Clermont, has been well shown by Dr. H. I. Jensen.’ The trend of the Canobolas to Nandewar line is about N. (true) from the Canobolas to the Warrumbungles, and N. 35° H. from the Warrumbungles ~ to the Nandewars. The line of trachytic eruptions is pro- longed in aS8.S.W. direction from the Warrumbungle moun- tains to the Gibraltar Rock near Dubbo. As regards now the chief tectonic lines in the great central coal-field, there are two well marked directions, the first set running more or less parallel to the general axis of the trough in which the basin lies, (in the Lower Hunter district this is shown by the Greta etc. faults, running from between H. 30° S. and EH. 10° S. to W. 30° N. and W. 10° N., in the southern coal-field they trend ina general H.S.H. and W.N.W. direction). In this first set of faults the throw in each case is in towards the centre of the basin. The other set of faults runs more or less parallel with the coast line. A well marked trend belonging to this set, is the flat asymmetrical anticline forming the eastern escarpment of the Blue Mountains. This was referred to by me in previous papers to this Society.” The general trend of this fold is N. 15° W. (true). It is to be noted that this structure makes an angle of nearly 35° with the fold of the continental shelf. It cannot therefore be correctly described asa parallel structure. The continental shelf has been ably described in detail by Hedley.°® ? Proc. Linn. Soc. N.S. Wales, 1908, No. 131, pt. 3. * This Society’s Journal, Vol. xxx, 1896, pp. 33-41; Vol. xxxvi, 1902, pp. 399 — 370, pls. xvi, xvii. % Presidential Address, Proc. Linn. Soec., 1909, and ibid. 1910. The heavy fracture known as the Hlderslee Fault, west of Branxton, has a throw to the west of perhaps 5,000 feet. ? Its trend is at its southern end N. and S. (true), and north of the Hunter River N. 9° W. (true). The strata in this part of the coal basin are thrown into a series of broad Synclines and anticlines whose axes trend a little W. of N. and H. of S. Their steeper sides face inland, as though the pressure came from the direction of the Pacific Ooast and pushed the strata in towards the subsidence region of the great coal basin. Thus there is evidence of a crustal] creep towards the coal basin, but along hinges of folding which have an orientation intermediate between that of the long axis of the coal basin and the trend of the coast line. It is the evidence of the new pressure lines, (which eventually merged into the epeirogenic uplift which eventually formed our coast line and Main Divide) beginning to assert them- selves. The principal lines of faulting in late Tertiary and _ Post Tertiary time, mapped chiefly on physiographic evid- ence have been ably described by Messrs. E. C. Andrews,” O. A. Stissmilch,’ and T. Griffith Taylor.* These faults in the Monaro tableland are not parallel to the coast line but diverge some 25° to 30° from it. The trend of these frac- tures is mostly between N. 5° W. and N. 10° W. (true). But in the case of the fault scarp to the east of the Gourock Range Mr. Andrews shows this as being parallel to the coast. In the New Hngland tableland the fractures on either side of the axis of granitic upheaval, as far as they have been traced, trend somewhat W. of N. following near ¢o the direction of folds in the older rocks. The newest 38 T. W. E. DAVID. 1 Geological Map of the Hunter River Coal-field, Geol. Survey, Dept. of Mines, Sydney. This Society’s Journal, Vol. xiv, pp. 420-480. 3 [bid., Vol. XLi11, pp. 331 —354, pls. ix — xil. * Proc. Linn. Soc. N.S. Wales, 1907, Vol. xxx11, p. 327; also Common- wealth Bureau of Meteorology, Bulletin No. 6,1910, “ The Physiography of the Proposed Federal Territory at Canberra,” PRESIDENTIAL ADDRESS. 39 scarps of all may be more nearly parallel with the coast, but this point yet awaits investigation. Mr. Andrews has well shown that in this latest epeirogenic uplift the maxi- mum effect was produced at the mountain knot of the S.E. corner of Australia where the meridional direction of flexing met the cross flexing of the Bassian lines (op. cit., pp. 431-2). The recent epeirogenic uplift which has produced the present Main Divide and coast line and accentuated the continental shelf has the form of a gentle wave with its steeper side directed to the Pacific, a fact emphasized by Hedley. Hence for some time past the tendency has been for the Divide to be forced inland, that is westwards, through the steeper eastern rivers capturing the upper portions of the watersheds of their more sluggish western neighbours. Quite recently a downward joggle has taken place for a considerable distance along the coast, especially marked along the seaward edge of the great coal basin. This depression has amounted to about 200 feet. A very recent negative movement of the strand-line to the extent of about 15 feet is so general around Australia as to suggest that it may have been due to a eustatic negative move- ment of the whole ocean surface in the Southern Hemi- sphere, due tosome such cause as a locking up of sea water in the snowfields and glaciers of the Antarctic following on aiter extreme deglaciation during an interglacial epoch. We thus see in New South Wales a marked example of development of two sets of tectonic lines, the older an orogenic set of strong folds with numerous normal and some overthrust faults in each case directed inwards towards that master warp the great central coal-field, the newer set, of an epeirogenic nature, is a gentle flex, the hinge parallel to the continental shelf, coast line, and present Main Divide; but the normal faults with downthrows away from the main axis of upheaval in many cases show by their 40) T. W. E. DAVID. orientation a compromise in direction between the older orogenic folds and the newer line of epeirogenic uplift. SECTIONS across NEW SOUTH WALES. M! Fig 7(a). Kosciusko ite 4 Yass-Canberra Ze eOree urrurundl ; S Basalt . Lake Denman; Zon e pee Ap arden ; aie ‘George Basalt M Hunter River: Tame nave Armidale; ichmond River Lambie if ault Clorenge River Mt iW Silurian, arning Coal! imeasures. 4 : Devonian etal Fault : : Permo- Carb? Carb*: ; — EP CHe=~-— & Ne, Serpentine Granite t Granite Commaniferors al es ” Ord? Ondavenn: Ord” Tae : es =\chs eRe - - Granite - - - Granite - - *&2Om- -Carboniferous--Silurian ~ - ~~ - Devonian eed chists : Fig 7(b). faut wee Dubbo anoblas B67F! — (volcanic) _Coal AERTS = Tibooburra Bourke tyrouck Coonamble 689 F ‘Molong ; Bathursr: : Trias on Permo-Car6$. ArTEsiAN —_ BASIN 350P = 300F" patesian } BASIN ‘Devonian : Si? + (Devs Coat measures F Cretaceous Basalt Cretacéous yee! ranite x SF efi P)\ Sito ee i PF ea MS SAVORS Gar’ ae eS 0 Jurassic cates RATS Bx Vendy aid 0 apne: = Aina: oth Woe pert es BAA HE ANZ. La UNKNOWN UNKNOWN A y; ny y 4: Probably chiefly Older Palaeo+,\-zoic and Pre-Camérian aN J Hy _rocks with belts of Granite. a: ES 3S URS Granife- - ---------------- Granite ----800 miles. Saseeee Ordovician.-Ord?. Gr Gpaaeea See SS > Queensland.—We may now glance at the salient points in the tectonic geology of Queensland. Reference to Plates 1 and 2 of this address reveal the following dominant features: (1) Ranges mostly of Paleozoic rocks forming the highlands of the Main Divide, an ancient peneplain trending about N. 33° W. (2) A great basin of newer and softer rocks, the Cretaceous basin, with at its S.H. extremity an older basin of soft rocks, the Trias-Jura Basin. This formsa Y, the lower stroke of which is the Clarence Basin of New South Wales. (3) A plateau of older rocks in the neighbourhood of Clon- curry, rising to the Barclay Tableland near Camooweal. (4) The Great Barrier Reef may be added as a fourth unit which has shared in the tectonic development of (Queensland. PRESIDENTIAL ADDRESS. 4] As regards topographical relief one of the most conspicu- ous features in Queensland is that of the steep-to Kanges along the northern coast. hese ranges form a very steep-to coast from opposite Hinchinbrook Island through the Bellenden-Ker Ranges, 5,438 feet high, (the highest ranges in Queensland) to the north of Cairns. The Bellenden-Ker are situated only about ten miles inland from the coast, and Hinchinbrook Island, formed of granites, schists, slates, etc., is 3,650 feet high. This steep-to coast has remark- ably short rivers draining eastwards, as the Main Divide is here so close to the ocean. Western rivers, like the Gilbert and Mitchell, on the other hand, flow down long gentle slopes to the Gulf of Carpentaria. This steep-to coast is situated, for the most part, all along the area ‘facing the Great Barrier Reef. | There can be no doubt that a very important tectonic feature is indicated by this remarkable type of coast. Mount Bartle Frere in the Bellenden-Ker Range is 5,438 feet above sea-level; is formed of granite and is yet only fourteen miles inland from the coast. Peter Bott, also of granite, and 3,311 feet high, is only five miles back from the coast. ‘“‘Rough Round Hill,’’ about one hundred miles north of Princess Charlotte Bay, only three miles inland is 1,543 feet high, and also formed of granite. In fact the Main Divide near the Bellenden-Ker Range just north of Cairns is only eight miles distant from the Pacific on the east, whereas the nearest ocean, the Gulf of Carpentaria on the west is 275 miles distant. This extraordinary position of the Main Divide taken in conjunction with the evidence of waterfalls like the Barron Falls, 800 feet high, and the numerous high granite and slate islands is almost certainly due to comparatively recent crust foundering on a grand scale along the region of the Great Barrier Reef, whereby almost the whole of the eastern side of the old oe - 42 T. W. E. DAVID. Divide has been let down below sea-level. Thus only a few miles of the heads of the eastern rivers have been preserved. As the result of this extreme betrunking they have become greatly overhung above the foundered area. Hence the steep-to coast and high waterfalls. The theoretical struc- ture of this part of Queensland, near Cairns, is shown on Fig. 8. SECTIONS across QUEENSLAND. Fig.8. Main Divide foundered and fractured East slope W. Chillagoe M*BartleFrere of the Old Divide Gulf of Devonian 5158 F Cairns : Holmes Reef Carpentaria ayo ; : P. Te Ae oe fare ?-\ : GrearBarrier |; DianeReef : Post - Tertiary Sa ACIEY fils i i 3 Qh (de tists, Slates $$$ 90 oo tS (Bp s ‘ ! ae Granite 500 - -Granite - miles.- - Carboniferous - - - - - -~- -— ----~~---- = As regards unit (1) the Main Divide, an examination of the geological map of Queensland shows that it is formed largely of granites, and so-called Gympie rocks’ which may be more appropriately termed the Star Series. These differ from the true Permo-Carboniferous rocks in containing Lepidodendron and Aneimites, allied to Rhacopteris, as. contrasted with the Glossopteris-Gangamopteris Flora of the Permo-Carboniferous System. West of Townsville the Middle Devonian rocks of the Burdekin System form part. of the Divide, and near Chillagoe Mr. R. Htheridge® has. recorded Halysites from Silurian rocks. Probably older rocks of slates, schists, quartzites, etc., extend from ~ Springsure to near Townsville, and from west of Canoona. in the Rockhampton District in the direction of Bowen. * As the Gympie Rocks in the type district now prove to be Permo- Carboniferous, in the meaning of that term as used by New South Wales. geologists, it is no longer an appropriate term for the Lepidodendron Beds of the older (Carboniferous or possibly Upper Devonian) formations. The term Star Series will be used in this address for the latter. ? Geol. Sur. Queensland, Publication No. 190. Records No. 1, vitl, pp.- 30 — 32. PRESIDENTIAL ADDRESS. 43 Enclosed between these two old belts of Silurian or Pre- Silurian rock is the northern end of the great coal-basin of Queensland. This extends to near the head of the Dawson River. Its main axis strikes about N. 27° W. (true). The long axes of the intrusive masses of granite follow approxi- mately parallel directions, as do the folds in the Gympie rocks. At its north end the Bowen Coal Basin is abruptly rounded offi by an immense bar of granite trending nearly due H. and W. (true). At Peak Downs the folds have a general north-easterly to south-westerly trend. At the Cape and Charters Towers the trend of the folding in rocks of Pre-Burdekin (Pre-Devonian) age is about W.N.W. and H.S.E.. W. H. Rands’ estimates that the schists and quartzites of the Cape River Gold Field may havea thick- ness, without allowing for possible repetition of beds, of from five and a half to six miles, they dip at 30 —35° towards S.S.W. At Chillagoe the folds strike about H.S.H.. In the Middle Devonian rocks of the Burdekin Basin the folds trend about N. 40° H. and S. 40° W. Dr. R. L. Jack, in 1894, wrote to me “* There is no evidence as to when this folding took place in Queensland as the Devonian is not seen anywhere in contact with newer rocks, and so we cannot tell whether they have been folded together or not. The hiatus, however, between middle Devonian and our next series (Gympie) itself implies an upheaval and in all probability a folding prior to Gympie,” (i.e. Carboniferous times.—T.W.E.D.) It is worthy of note that these Burdekin folds trend at right angles to the adjacent coast line. In the Gilbert Gold-field, still further north, there are two well marked sets of folds, trending respectively H.S.H. to W.N.W., and * On the Cape River Gold Field. By authority Brisbane, 1868. W.S.W. to H.N.E. The latter are in sympathy with the Burdekin and Kimberley lines, and the former with those of the Cape Gold-field and the New Caledonia to New Guinea lines and the Charters Towers granite axis. Dr. R. L. Jack wrote me in 1894, ‘* The folding of the Gympie formation |Gympie here used in the sense of Pre- Star (that is Pre-Upper or Middle Carboniferous) and Post Burdekin (Post-Middle Devonian)—T.W.1.D.| must have been the chief factor in the evolution of the eastern coast range. That it took place before the deposition of the Star formation I have little doubt in my mind, as the latter though nowhere observed in contact with the Gympie, is comparatively undisturbed.’’ Dr. Jack would probably in view of later paleeontological determinations which show that much of the Gympie beds are really newer than the Star beds, and that the Gympie has certainly in places been folded fairly strongly, see his way to modify this statement, so that one might conclude that one of the chief factors in the evolution of the Main Divide has been the folding of the Carboniferous and Permo-Carboniferous rocks along lines mostly coincident with the long axes of the granite batholiths. Trend lines are also indicated in the Main Divide unit by the general distribution of the main basalt flows and volcanic foci. Notably to the east of Clermont these foci are grouped along N. 40° W. and S. 30° H. lines. 44 T. W. E. DAVID. Dr. H. I. Jensen’ has indicated the trend lines of the foci and general zone of the alkaline lavas in the Mount Flinders and Fassifern districts and the east Moreton and Wide Bay districts. In the former district the zone trends about N.E. and S.W. (true), but the local groups of volcanic foci appear to trend about N. 15° W. toS.15° H. (true). In the * Proc. Linn. Soc. N. S. Wales, 1903, pt. 4, ap. 842 - 875, pls. xlvi—1; abid., 1906, pt. 1, pp. 73-173, pls. v, vbis—xvi; ibid., 1908, Vol. xxxiil, pt. 3, pp. 491 - 588, especially p. 585 ; ibid, 1909, Vol. xxxiv, pt. 1, pp. 67 | - 104, pls. i- vi. ; PRESIDENTIAL ADDRESS. 45 latter district the trend is N. and S8. (true). Trend lines are also shown by the belt of serpentine to the west of Gympie (about N. 10° W., true) and the immense mass of serpentine to the north of Rockhampton. The latter trends N.W. and S.E. true, and is evidently situated on a zone of heavy fractures. These extend all the way from Gladstone to Herbert Creek at Broadsound. The trachyte volcanic centres of Yeppoon and Berserker Ranges are close to these major lines of fracture. They are doubtless part of the group of great fractures along which the former eastern side of the Divide has been stepped down below sea-level. There is both physiographic and stratigraphical evidence for this fault at Curtis Island. Mr. Lionel V. Ball, B.£.,° shows on map 11 of his instruc- tive report, that there is a basin of Burrum Beds (Trias, or Trias-Jura) thrown against Devonian rocks. The Boyne River follows this line of fault, which, presumably throws to H. 40° N. The channel between Curtis Island and the mainland is on a continuation of this fracture. Beyond Keppel Bay it seems to divide, an eastern branch going to Shoalwater Bay and the Northumberland Islands, the western to the estuary of Herbert Creek, at Broadsound. Another profound fracture, observed by me in 1891, bounds the Styx River Coal-field on the Hast. I estimate that it has a throw of fully 3,000 feet. It is probably prolonged to where on the chart of the Barrier Reef, north of Broad- sound, the note occurs “‘it is unsafe to pass to the eastward of this line.’’ If so, this fault has a length of fully 250 miles. This trends in aS. by EK. direction, striking for the Dawson River to the east of Duaringa. Several important faults have been recorded by Mr. B. Dunstan in this region. * Geol. Surv. Queensland, Publication No. 194, “Certain iron ore, manganese ore, and limestone deposits in the Central and Southern Dis- tricts of Queensland.” Brisbane, by authority, 1904. wy § ™ The trend of the ‘‘Gympie’’ and Permo-Carboniferous- Glossopteris Beds is, according to Dunstan, about W. 40° N. with a dip to S. 40° W.*| The Cumberland Islands and Whitsunday Island are almost certainly horsts amongst a network of faults. The trachytic volcanoes described by Mr. A. Gibb Maitland’ to the W. and N.W. of Mackay, such as Mount Mandurana, Mount Jukes, etc., mark a continu- ation of the disturbance lines in this zone, upon which are seated the above extinct trachyte volcanoes. A few other important fault lines may be mentioned. Dr. Jensen’ figures a probable line of fault running from near Mount Flinders ina N. by W. direction to the west of Ipswich. Several faults are figured on the geological survey maps of the Ipswich Coal-field, these have a general trend N.W. to N.N. W., with a throw to N.E. Dr. Jensen* has figured a fault north of Brisbane, striking W. 40° N.toS. 40° E., and throwing probably at least 1,000 feet to N.40°H. To the south-west of this fault lie the phyllites, hornblende schists, glaucophane schists, anthophyllite schists, cyanite-rutile granulites, etc. of the Mount Mee and D’Aquilar Range area. This appears to have been the core of the old Main Divide. In the Gympie Gold-field are a large number of faults which have been mapped by Mr. W. H. Rands, F.G.s.,’ and Mr. B. Dunstan.® The ‘‘ Smithfield OCrosscourse’’ runs H. 10° N. (true) with a N. 10° W. downthrow of 530 feet. The normal strike of the Gympie strata is in a general N. by W. and S. by H. direction. The Inglewood Fault strikes near K. 46 _ T. W. E. DAVID. * Geol. Surv,, Queensland, Bulletin No. 11. Report on the Geological Features of the country between Warren and Mount Lion in the Rock- hampton District. Brisbane, by authority, 1900. * Geol. Surv., Queensland. Geological Features and Mineral Resources of the Mackay District. By authority, Brisbane, 1889. 3 Proc. Linn. Soc. N. S. Wales, 1909, Vol. xxxiv, pt. 1, pp. 67 —- 104, and specially pl. i. * Proc. Linn. Soc. N. S. Wales, 1906, Pt. 1, p. 103, and see fig. 3, p. 76. * On the Gympie Goldfield. By authority, Brisbane, 1889. ®° Report of Geol. Surv. in course of publication. PRESIDENTIAL ADDRESS. 47 30°S., with a throw to N.30° H., and the Laing’s Fault strikes N.N.W. to N.W., with a throw towards N.E. An important tectonic structure to the south of Princess Charlotte Bay, to the north-west of Cooktown is the sen- kungsfeld of the Little River Ooal-field. This strongly marked trough is well figured by Dr. R. L. Jack." The indent in the coast at Princess Charlotte Bay is probably of tectonic origin. A significant fact in the structure of the unit of the Main Divide of Queensland is the newness of the folding and faulting. In the southern part of New South Wales the Permo-Carboniferous strata are simply thrown into broad undulations. In the New England district they are strongly folded and altered by granites. At Gympie they are much disturbed and considerably altered in places. About five miles north-west of Gympie specimens of Protoretepora occur completely replaced by stibnite.’ The Trias-Jura Coal-measures of the Styx River at Broadsound are thrown into broad folds,and at Maryborough the Maryborough Beds, classed by R. Htheridge as of Upper Cretaceous age, dip at angles varying from 7 — 12° up to 30—45° on the Isis River, as recorded by W. H. Rands.? The general dip is north-easterly. Nowhere else in Aus- tralia, as far as Iam aware are strata as new as Upper Cretaceous so much disturbed, as in the above district, The comparatively recent character of the volcanic erup- tions in the Cairns district is proved by the crater lake surrounded by scoria described by Mr. Meston, Lake EKacham.* The great submarine volcanoes perhaps the largest, which have as yet been discovered in the Australian + Report on the Little River Coalfield. By authority, Brisbane, 1882. * Geology and Palzontology of Queensland and New Guinea, Jack and Etheridge. By authority, Brisbane, 1892, p. 83. 3 Report on the Burrum Coal-field. By authority, Brisbane 1896. * Geol. and Pal. etc. supra, p. 587. 48 T. W. E. DAVID. region, lying between 104-128 miles east of Brisbane are probably of recent origin. ‘These have been referred to by ©. Hedley,’ and are shown on the accompanying fig. 9. Fig.9 NW. Bi ie . Submarine Silurian GREAT ARTESIAN BASIN rae Main Volcanic Peaks Cloncurr: Minton Longreach Blackall rias-Jura Divide PostTernary? teed: 9 Basalt Sandstone Basalt Brisbane , _, fathoms on Marine Cretaceous Marine ; Cretaceous Strata Pept Marine Care. oe ‘nfo Ha a UNKNOWN Att some if forte Probably mostly older Paleozoic rocks with belts af ri Older and newer cocks Permo-€a Graaite -- - -------------------------8OO miles.----- -----------Granite-Granite- -Faults--? The highest of these mountains is about 14,000 feet in height, at Lat. 28° 42’ 2", Long. 155° 37’ H. As far as can be judged from the soundings these submarine volcanoes have a general N. by W. to N.W. trend. As regards unit (2) the Queensland portion of the Great Artesian basin, little need be said from a tectonic point of view, except that the basin represents an area which was partly covered by great warp lakes in Trias-Jura time, and wholly covered by sea in Cretaceous time. The basin was deepest near its centre just over the border of South Aus- tralia from Queensland. There the sediments of Cretaceous and perhaps Trias-Jura age in part are a mile in thickness. Between Cloncurry and Hughenden (J. B. Henderson)’ a large sill of Paleozoic rocks, rising to within about 1,000 feet of the surface of the ground, forms a partial subter- raneous barrier to the Artesian basin. It trends in an H. to W, direction. The north-westward flowing tributaries of the Darling, suchas the Bogan, Macquarie, Castlereagh, Namoi, Gwyder in New South Wales formerly entered the south-eastern shore line of this Cretaceous sea by separate mouths. Subsequently, in Hocene time, a broad epeirogenic uplift supervened raising the whole basin, especially in the 1 Proc. Linn. Soc. N.S. Wales, Vol. xxxvi, pt. 1, pp. 32, 33. * Hydraulic Engineer’s Report. By authority, Brisbane. PRESIDENTIAL ADDRESS. 49 direction of New Guinea, the southern shore line of Aus- tralia undergoing submergence in Victoria, the southern part of South Australia, and the south-western part of New South Wales. This tilting from N. toS. in time started the Darling, the Bogan, and Macquarie rivers etc., now forming what Mr. T. G. Taylor’ has called ‘ boathook bends’ with the main stream. (3) In reference to the third unit, that of the Cloncurry region ascending to the Barclay Tableland beyond Camoo- weal, information as to its tectonic lines is at present very meagre. As regards recent uplift, as shown by Mr. E. C. Andrews,’ the Main Divide of Queensland has been warped up synchronously with the Main Divide of New South Wales. Dr. Jack’ has pointed out in an able lecture, quoted by Mr. Hedley, that the Main Divide of Queensland was formerly close to Brisbane, but now has been pushed west- wards by the rivers draining the eastern, the steeper, slope of the warp, so that it is now, at the latitude of Brisbane, some 50 miles west of its former position, owing to the east- ward flowing rivers having cut back their channels through the hard argillites and granites, just west of Brisbane, into the soft rocks of the Ipswich Coal-measures. Their progress further west has been checked at Toowoomba by the great sills and flows of basalt extending for some distance N.W. towards the head of the Burnett River. The latter river and the Dawson are fast eating their channels back through the Trias-Jura, and are touching the sediments of the old Cretaceous sea. The Nogoa and Belyando Rivers have broken right across all the old rocks of the plateau of the old Main Divide, so that now around their sources the Main Divide is situated on the Upper Cretaceous, Desert * Commonwealth Bureau of Meteorology, Melbourne. Physiography of the Proposed Federal Capital Site at Yass-Canberra, Bulletin No.6, p. 8. ? This Society’s Journal, Vol. xuiv, pp. 420 - 480, 3 Lecture Reported in Brisbane Telegraph, 22/5/94. D —May 8, 1911. 50 T. W. E. DAVID. Sandstone, rocks. Further north in the Oairns District a portion of what was perhaps the original old Divide still survives. In this case heavy crust foundering has all but completely effaced the old eastward flowing river system, leaving so narrow a Strip of eastern watershed as to make it impossible for any great rivers to gather, in the ten miles which intervene between the crest of the present Main Divide and the ocean. It seems strange that the very powerful lines of upheaval of New Guinea running about 4.S.H. and W.N.W. have left so little impression upon the tectonic plan of Australia. Possibly the W.N.W. to H.S.E. trend of the schists of the Cape River Gold Field is due to these New Guinea pressure lines, as well as the N. toS. tilt of the Cretaceous Basin and tilt of the Ordovician rocks near the Victoria River in Northern Territory. New Guinea.—Brief reference will suffice for what is known as to the tectonic lines of New Guinea. At Port Moresby Mr. A. Gibb Maitland’ found strata formed of sandy limestones and calcareous shales with flints. These contained a Voluta which Mr. C. S. Wilkinson, the late Government Geologist of N.S. Wales, considered to be of Miocene or EKocene Age. The Rev. J. H. Tenison-Woods considered the formation to be Pliocene. Lithologically the material somewhat resembles that of the Hocene beds of South Australia, which is also characterised by the presence of flints. The strata are steeply inclined, often vertical, the dip generally is E.N.E. to E. 30° N., at 30—55°. Merid- ional strikes with vertical dips are also recorded. At Yule Island the dip is N. 40° H. at 20—30°. At Ware (Teste) Island the limestones are folded on N.and8. axes. Atthe island of Kinauro (Cette) the dip is W. by N. at 50°. Ina recent letter Dr. W. G. Woolnough, informs me that he 1 Geological Observations in British New Guinea in 1891. PRESIDENTIAL ADDRESS. 51 thinks, as the result of a personal examination of the beds, that the pressure came from the north. Dr. Lorentz’ has referred to limestones discovered by himself in the Wilhel- mina Range as of Cretaceous Age. He calls them Alveo- lina limstones. They have been uplifted to over 14,000 feet above sea level. A good account of the geological structure of German New Guinea is given by P. Steph. Richarz.” = for the 4th quarter. 84 G. H. KNIBBS. In these expressions D,, D., D, denote the differences of the daily averages for the quarters (with the proper signs): T,, T., T;, the intervals, all being regarded as positive: and Q the length of the uniform quarter in days. In the case of the correction for the half-year, the daily average being still the datum, we have for the correction D being the difference (with its proper sign) of the daily averages for the two half-years; T the interval between the end of June and the middle of the year, reckoned posi- tive: and S the length in days of the uniform half-year. The correction is positive for the first half year and nega- tive for the second. These corrections are often so small that they may be neglected. Corrections for the unequal lengths of the years in a decennium are usually quite negligible. They may, of course, be computed on the same principles. 5. Equalised months and years.—Statistical results need- ing analysis can also be put in a suitable form by using as original data results for equalised months and years. The scheme should be as follows :— Inasmuch as the year 2000 is a leap year, the period of 199 years lasting from 1st January 1901 to 31st December 2099 may be regarded, for statistical purposes, as consisting of years of 365; days. Both months and years may then be readily equalised by making the months 3654 + 12 = 30x days, and considering the first of the month as falling differently in each year of the cycle of four years, accord- ding to the following scheme, viz.:— STUDIES IN STATISTICAL REPRESENTATION. 85 1901 1902 1903 1904 Years. 1905 1906 1907 1908 LCS 1910 1911 1912 etc. etc. ete. ete, seeived Beginning of Equalised Months. January Jan. O 0545 0535 012 February | Jan.30;5 °* 3075 3078 31,3;* March Mar. 144 aes els 122 April April 1535 1s 143 1-3; May May 14% 2 ore eG June June 1,35 lie ]42 018 July July 14¢ re 2525 155; August Aug. lis lits Wee: O1¢ September | Sept. 05%; 032 1 Mean October Oct. 042 133; 1 032 November | Nov. 0-5; 0+? 024 O22. December | Dec. 042 1+ 1,5; 0-2- January Jan. 0-4; 0-8; 032 0 * Feb. 0,3;. That is, the beginning of the equalised month or year will fall regularly into a new position each year in the cycle of four years, but this position will be repeated four years later. In allowing for change of absolute or relative num- bers for each month the principles already indicated may be followed. 6. Analysis of annual fluctuations. Quadrimestral and quarterly data.—A large number of statistical results may be more or less approximately represented by fluctuations which have an annual period; the simplest instance being those whose instantaneous value is representable by (10)...... y=a + bsin (« + £) the integral of which is StOn).....; Y=/{a+bsin(« + B)}dx = ax — bcos («+f) 86 G. H. KNIBBS. Since the form in which the data are usually furnished is that of average values for a period, e.g., monthly, quarterly etc., the data in question are not given in the form of equation (11) but in the form Y/fd« = y’; ie. Y/(§7) or Y/($7) for the cases of monthly or quarterly statistics as the case may be. Going back to equation (10a), it is seen that, if the data furnish values for half years only, then y’ = Y/z, and a is the mean between the two«values of y’: also either b or 6 may be arbitrarily assumed and the other then deduced. Ordinarily it will suffice to put 6 = 0. If, however, results are given for thirds of years, a unique solution for a, band 8, maybe obtained. Integrating (10a) 2x Or 4a 4 ° ° T between the limits 0 to 3° 3 to 3° and 3 to 27, the group results are :-— qY, = 27a + 4b(83 cos 6 + v3 sin f) Y,=27a + $b(- 2v3 sins) Y; =27a +4b(- 3cos f+ v3 sin £) “arr Whence dividing by fa dx ons we get, in each of these "0 expressions y’, instead of Wi a instead of 27a/3 and 3b/4m instead of 4 b.= Hence primarily, by addition { Cl) sa: 3a = yityetys; thusa = t(yity2t+y%3) and 3 V3 Yyi-2yot y3__a-Yo _ un bsinf (OS ears ee ha pant= + tan B or and, £ being ae we have (43) cscs! b= 20 (a—y'2) cosec 2; or (t3.a)))).ui b= = * (y:—y's) sec B. STUDIES IN STATISTICAL REPRESENTATION. 87 In practice, however, results are only rarely given in thirds of years. Usually they are quarterly or monthly. In the former case, if the sum of the first and third quanti- ties equal the sum of the second and fourth, we may suppose the frequency to be of the form @4)...... y = a+ b sin (« + f) The data do not allow of the inclusion of more terms except by making arbitrary assumptions which can in general have no validity. [If for example in equation (14) we add one term so that it becomes (14a)...... y =a-+ dsin («@ + 8) + csin 2 (x + y) we should have only four equations to determine the five unknowns a, b, 6, c, y, and we could obtain a complete solution only by making some assumption such for example as b =cor/ =yorthat y= 0.] In the case of monthly Statistics the frequency may be supposed to be of the form (15)...y = a + qm sin (« + a) + ae sin 2(% + a.) + ds sin 3(# + ;) + ...... the final term being d¢. It is first of all necessary that ~ should either be expressd in rates (calculated correctly for equal periods), so that the numbers may be independent of a secular change taking place during the period under review; or that the absolute quantities should be reduced to a common datum. For example, if the absolute number of births during a period is given, it must be reduced to birth rates or corrected so as to express what it would have been had population remained constant during the time under consideration : so that for example the final formula for absolute num- bers will be of the form (16)...... Y= Pe? {a)+a, sin (e-+o,) +a, sin 2 (x+o)+ ete. } Y being the absolute number of persons, and P being the absolute number for « = 0. From (14) above we have for quarterly fluctuations t= 0,57, mom, oT. 88 G. H. KNIBBS. and since (17)... /{a + b sin (x + B)} du = ax — bcos (« + B) the following are the values for the integrals between the limits indicated, viz., for the case where sum of first and third quarters equal sum of second and fourth. Y,=47a + b(cosf + sin 8); Y2=47a+b (cosf — sin B) Y;=37a — b(cos8 + sinf); Y,=$z7a—b (cos 8 — sin f) Let y', = Y'./37, in which k = 1, 2, 3, and 4, and yay y', and y, are the corrected quarterly means. Hence in these expressions we may write y’, instead of Y,; a instead of 47a; and 2 b/z instead of b and we thus obtain (18)... a=%F (y) Se Ye vig Y's aE y's); and also OTe sh eet ’ , = Cia) Bp (C8) seco TY = = tan 8 Yi Y 2 Y 3 Y 4 cos and 6 being thus found, we have (20)... b= rahe - y',+y's) cosec P = uit y>—ys— y) sec B If, as is very commonly the case, the sum of the first and third quarters is not equal to the sum of the second and fourth, we must introduce another term into the frequency, say c sin 2(«+y); then making c = b in accordance with the arbitrary assumption already referred to, the frequency becomes =a+t bsin (« + 8) + b sin 2(« + y) Proceeding on the same lines as before we have yi=at ah (cos 8 + sin 8B) + ae cos 2y yo=act 2p (cos 8 — sin 6) — 245 cos 2y 43 — 02 = 20 (cos B+ sin @)+ = cos 2y Ys= a — = 0 (cos 8 — gin B) — =p cos 2y STUDIES IN STATISTICAL REPRESENTATION. 89 from which, as before we obtain (18), (19), and (20), and further :— (20a)... b Cos 2y = a ae Yot y's 7 y's) from which we have 20b)... cos 2y = (y' = oat y's y's) sin P. ii TS (yaa y= yy) G 7. Annual fluctuations: monthly data.—With monthly average results reduced to a uniform basis we put, [see (1) and (4) | 214 Oe JS (Q+a, sin (@+4))+...... +a, sin m (a+ ,,) } da = (ht — 1, COS (+4) —...... — = On cos m(x+a,,). For the monthly averages, the integral is taken between the limits 0 to 47; 47 to $7; etc. Consequently if the right hand side of (21) be divided by $7, the monthly means (not aggregates) are obtained as a series of twelve equations of which the first is 6 g 6 ( us y 6 $= —-—. a, {cos (+m) — ae = A ‘con ates)| aia I | 0) the second is | ee | KF lines IS Gy—a,— — . @, 1c0S(+m)| —— . 3 a, 1cos 2(e+a,)+—.,, Hy | |x ia jas e and so on. Summing these vertically, we see that Si A Sa cewcas + $s. = 12 a; thus Ps. Gy =e 8: It is desirable for the purposes of computation to form the quantities s; — a 3 Ss: — a 3 ete., which will be denoted by r., 7, etc. Thus | n= 6 [a, {cos a, — cos (a, + 30°)} +4 s{ COS 2a, es —cos 2 (4,.+30°)} + 4 4;,{cos 3a;—cos 3 (a5 +30°)} +... | i, = 2 [a,i cos (a+ 30°) — cos (2,+ 60°} + £a,{cos 2(a,+ 30°) and so on. —cos 2 (a,+60°)}+...] 90 G. H. KNIBBS. These last equations reduce to r, = ©[a,.2sin (a, 415°) sin 15°+4 ay. 2 sin (a2+15°) sin 30° aa + za;.2 sin 3 (a, + L5°) sin 45° + ete....] aa Tan .2sin (a, +45°) sin 15°-+4 ay.2-sin (a+45°) sin 30° + 74;.2 sin 3 (a, + 45°) sin 45° + etc....] etc., etc., the angles increasing downwards 15’, 45° 75° etc., and horizontally 15°, 30°, 45°, etc. The following results are now obvious :— (23)..tor = 2 fan sin 2 (a-+15°)+ ~ asin 4 (0-415) + $a, sin 6 (a, + 15°)] (24)... = [as sin 2 (0,+105°) +P a, sin 4 (a, +105") + 2a, sin 6 (a, + 105°) | etc. It is thus evident that by making suitable combinations the whole of the values a, dz, d3...d5 and %, %...¢, can be obtained, and if «, be assumed to be 0, then a, can also be obtained. | For example we have from (23) and (24) (25)...?i + Pa P+ li = ae a, sin 4(o,+15°) =I, say, similarly (25a)... t fst gt Pu = mee a, sin 4 (a,+45°) = L, V3 (25b)...13+ fet rotte = eS a, sin 4 (a,+75°). = Ty. These last three equations may be written (6). b= i eatin Ai 8 boa.4a (26a)...In= 9% 4, , gin 40, (26b)...L,= eS a, (sin 40, — = cos 42.) from which we obtain STUDIES IN STATISTICAL REPRESENTATION. 91 673 , i ees se oe sy ee =) La Soe ma oy : (COS fel Mane eet ‘| |/Having obtained a, we have (28)...a, = - aay Meter t retry) cosec 44,. To get the terms a; and «; we form the sum 7,+7;+7, and the four possible similar ones. All the terms cancel each other except a; and a; and we thus obtain (29)... m+75 +15 ee [a;./2 sin 3(¢;+15°) +a, sin 6(¢,+15° YI = = M,, Say (29a)...72+ rt toe [a3.v2 sin 3(a;+45° ) + Gs sin 6(0,+45°)] == Me (29b)...73+ 77+ ee [a;.v2 sin 3(a;+ 75°) +a, sin 6(4,+ 75°) | — ins (290)... 05+ r= © fap. v2sin 3(uy + 105°) + asin 6(%+105°)] = M, from which the following are derived, viz., asa 28D (30)... ae a ee i = — tan 3a; ms one — Sa, .2 cos 3a, | (31)... and a; = a [ (Po+%6+ Pio) + (71+75+1%)| sec 3a, To obtain a, and 4, we proceed as follows (G2):..... 1-147 — Pio = a [2 a. sin 2(a, + 15°) + ~ as sin 6 (4,+15°)] = M, say, (32a)... r2—%s+%s—Tu = zs [2 a, sin 2(4, + 45°) + 4 ag sin 6 (45+ 45°)| = Nos (32b)... %3—Tet1o—-Pe = 2 [2 as sin 2(4 + 75°) + thus < ag sin 6 (4 +75°)| = No; Bie 2 dz. V3 Sin 2a, 1 (33)... Di Ns ys i= Gant ae, Bee cee Eilon) ions 20) 92 G. H. KNIBBS, and o, being thus determined we can derive a2 from the equation (34)...d. = co a(n V4 FP V7 =| 110) ey (1; aad Vs sie Ts oa rs) COSEC 2a, The values of a, % and a;, 4; can be determined from one operation as follows :— (35) oe — +73 —17o= fh, = 24v3 ae cc sin 15° sin (a, + 45°)—- F a; sin 75° sin 5 (4,+ 45°)| 24V 3 (35a)...%2— 1st fi-— Pio = Re = —— [a, sin 15° sin (a, + 75°)— + a; sin 75° sin 5 (4;+75°)] (35b)...%3— 1) + 15 — fu = Rs = ee [a, sin 15° sin (a, + 105°) — x d; sin 75° sin 5 (a;+ 105°) | (35¢)...1%4— Pip + 15 — Pe = Ra= gue [a, sin 15° sin (4 +135°)— = a, sin 75° sin 5 (a, +135 °)] From (35) and (35b) by addition (36)... Ri + R= v3 oe C sin 15° sin (4, + 75°) + = a; sin 75’sin 5 (45+ 75°)] from (35a) and (36) we have by Sanaa and subtraction (27a Re Re we a sin 1D sina oe Go nihes heh a = rm . Fa, sin 75° sin 5 (as +75°) Similarly from (35a), (35b), and (35c) we deduce (39)... R.+R +R, v3 = 2S a, sin 15° sin (o,+ 105°) (40), OR, R, v3 = Add ; 5 A sin 75° sin 5 (0,+105°) Ue and further R.+ Ri+ RB; V3 en sin (a4: 105) 2 3 oe ae c So Feeccrs) are) /3 4 Sindc. Gaaoe) 0 ee cot (cuties R.+ Rs;— R; v3 ~ sin 5(a;+ 105°) _ Baa ° (42)...2 Bok, 2 7 sind @+a5) eae STUDIES IN STATISTICAL REPRESENTATION. 93 which determine « and «;; when a, and a; can be at once deduced from (39) and (40). Lastly reverting to equations (29) and (29b) we see that (43)... + rst fst tt fottn) = (Het tst ret st fit Me) = Jee - Ag - COS 6 a, The data are not sufficient to enable us to determine both a, and o,, but with data thus restricted we may assume «, = 0 and we get at once the value of the amplitude ay. (44)... a a T prio The data at our disposal do not admit of solutions for terms higher than 62. mbt + ttt ta | 8. Quinquennial periods.—Quinquennial. periods with yearly results only are fully represented by two periodic terms. Let Y, ¥:... be the yearly results and q,, q.... the yearly means, then * Bae (45)...¥%, =| la+p sin (e+ ?)+e sin 2 (x | dx 219) and if Lee 5 ele « (46)...q. = % sii a+5~{b cos 6 (1— sin 18°) + b sin B cos 18° + 4c cos 2y (1 +. cos 36’) + be sin 2y sin 36°} with four similar expressions indicated in the table here- under. If sin 18° be denoted by s,; cos 18° by ¢,; sin 36° by s, and cos 36 by ¢:; the coefficients of b cos 6, b sin P, 4 © cos 2y, and $c sin 2y inside the bracket are given by the following scheme :— Mean. b cos B 6 sin B 4c cos 2y 4c sin 2y q l1—s, Ci tier So "Fe Sy +C, Sg —C, (5) = 5, = Siot= iC 5 Fs 0 —2 8, 0 2s Ws —8,—C, So— Cy C5 84 —8,—C, Ys ES Cy Sl Ee So 94 G. H. KNIBBS. Primarily we have, (47)... = E(u + atat ata). Then denoting the differences of the means from this quantity by 7, etc., we have (48)... W@-G=%13 G@—-G="}; etC...... then r; = a 2 sin 36. bsin 8 +2 cos 18°. Fesin27| and 4 (7%) + i) 2 (cos 18° . b sin 6 +sin 36° . 4c sin 2y) from which we obtain - ax 20 3 (Toate Silos (49)... b sin f 5 2 sin 36° sin 18° + cos 18° Further %—Vs = = 2 b cos 6 (1 —sin 18°) + 2(1+ cos 36°)4 € cos 2y| ot {2 b cos f/ (sin 18° + cos 36°) — 2 (sin 18° + cos 36°) +e cos 2y| Consequently NE Y, — £ % - £ 50)... (ta Shot 2 4 | = (aD) 5 (1+ cos 36 aes nai ae 9 sin 18° ij= ne 1 ) b cos | Sin 1 b cos f (2 i+ sn 18°) which determines b cos (6 and then from (49) we can obtain tan (6 and thence b. 9. Tabulation of terms as faras 6x.—The table hereunder gives the trigonometrical coefficients for terms up to 6x inclusive. In order to find, as is necessary, the several terms in the expansion of r,, r. having the value assigned to it in § 7, viz., NIT Gin =D al — a, cos (x+a,) — 4 ay COS 2(H+45) — 10.00. | af 1) = n— 1) 6 We may note that, ignoring the multipliers a, a.... and the 6 e e es constant —, the co-efficients of COS %, Sin 4: COS 4, SIN 4%: T COS 43, Sin a;...: are given as far as the term involving 6 in the table hereunder. TABLE OF OO-EFFICIENTS FOR SUB-DIVISION OF TOTAL PERIOD INTO TWELVE PARTS. -_h= ADIN In the following table? = 1+ S10 as sin a, SIN ag COS ag COS a; sin a, COS d, SIN ay COS a, sin as COS My COS a, S490 1S Oo 1O.2. Oo 2. oO leo pat) [00 rio3 leo os IN loo fe leo leo leo loo ~~ to) rio jo ie fend lo mn as Pp QS aloo} joo C arjoo rioo leo loo F leo lcs erica le ileo Pleo ico rho = rico loo f loo rico joo f rico hye So | cit ein ist mIN el OC) calle) le DO) roo 0 les rin ealoo loo IN Swrandawe Sf SF w2 anrn we § rat | | | | Mi 10. Illustrations of applications of sine formule, mar- riage rates.—The application of the formule for the fluctu- ations may be illustrated by the following examples. The corrected mean of the marriage rates for the Commonwealth during the years 1907-9 is given in the following table :— 96 G. H. KNIBBS. June 7:87 March | April 7°65 | 10°40 Nov. 7°36 May 6°99 July 7°23 Aug. 7°05 Sept Oct. 7°87 | 7°30 Dec. 8:13 Feb. 8:01 Jan. 7°52 If we group these in four-monthly periods, the three averages for these periods are 8°40: 7°28: 7°67: The frequency is y =a + bsin (#@+ f); and a = $+ (8°40 + 7°28 +-7°67) = 7°78 018 —=T 28) 840-767 =3v3 Therefore tan 8 = 1°186 and 6 = 49° 52’. Lastly b = = (8:40 -7°67) sec 8 from (12a) = 69875 = on eae CouGua to) mai. R,+R,+R.v3 32°80 + 31°696 Hence cot (a, + 75°) = — 1°439; thus 4, = 70° 12’. Then from (37) we have by = (ey ay Bette 3) 74 cosec 15° cosec («; + 75°) = 0°293 = 9°450 x °0218 x 3°864 x 11°951 = 9°513. From (33) and (34) a,= — 1°1833 o, =65° 31’ Krom (30) and G1) a;—— =, 0:155- o, —- 26 6 From (27) and (28) a,= + 0°099; a,—= 34° 30’ From (40) and (42) a;= — 0°046; «,=4° 36’ Lastly from (29), (29b) and (44), we have ») (AL de aba (apr) ae Ry oe oe sy COS 4% and if we assume that «4, — 0; then a, — —0°047. The frequency is thus = 62°08 + 9°513 sin (« + 70° 12’) — 1°183 sin 2(a+ 65°31’) + 0°155 sin 3(« + 26° 6’) + 0°099 sin 4(x + 34° 30’) — 0°046 sin 5(« + 4°36’) — 0°047 sin 6x which will give the group means from which they were derived, as may be readily verified. | The figures given in (4) representing daily number of persons committing suicide in the Commonwealth during the decennium 1900-09, may be taken by way of further illustration of the analysis into periodic series, and by way also of indicating the time-relation of the two series (see also § 13 hereafter). = STUDIES IN STATISTICAL REPRESENTATION. 99 . The average population during that period was 3,995,800, hence the average daily number of suicides per million of inhabitants is obtained by dividing the figures in (4) by 3°9958. The results are shewn in the following table :— Daily suicides per million inhabitants.—Equalised months. Jan, Feb. Mar. | April May June July | August] Sept. Oct. | Nov. Dec. °3589 |'3714 |°3349 |°3359 |°3096 |-2838 |-3008 |°3256 | 3071) -3531 |-38233 | -3451 By addition, as before, 1 € e — 12 Pea SO) se. 3451 | = °3291 The determination of the constants is effected as in the case of the temperature curve. The resulting frequency is = 0°3291 + 0°0354 sin (« + 72° 4’) —0°0117 sin 2 (a + 73° 22’) + 0°0031 sin 3 (x + 12° 49’) — 0°0142 sin 4(« + 40° 52’) —0°0131 sin 5 (« + 0°16’) + °0104 sin 62. 12. Reduction of epochal angle to days —It is sometimes desirable to reduce the epochal angles of an annual series to days, particularly in the calculation of “‘lag.’’ See § 13. Since an angle of 360° corresponds to 365°2422 days, the following approximate relation holds between D the number of days and g the epochal angle expressed in degrees 1 yah 1 1 it 62)... D=9 (1+ i99 +3007 a000 + 30000 + TOo000 which gives 365°2416. As many terms can be used as are necessary, and the result can frequently be written down by inspection. Asa rule it is sufficient to stop at the term ;.. Another convenient relation between D and g is 1 2 1 ee a5 — (62a)... D=9 (1 a ade een which gives 365°2421, and in most cases it would be sufficient to stop at the term =. 13. Determination of “lag” in correlated phenomena.— Given two periodic series of the same periodicity, viz., ie 100 G. H. KNIBBS. (53)... Ym == sin m (x +2): (ii) y'n = sin m (a + B), then since the values of each are 0 for the value x= - a and «== — 8 respectively, we may say that the “lag” of the second behind the first is given by (54)... \==a — (6+ 2nz) In general we may assume that n — 0, in the term 2nz, that is to say, in the majority of cases practically arising, the lag will be less than a whole period. Hence if we have reasonable grounds, apart from mathe- matical considerations, to look on them as causally related, then the second may be regarded as an effect of the first brought about after the lapse of time». Thusthe lag may be determined term by term when “‘a priori’’ we know the length of the period, and we should thus have for the lag of the ‘‘mth’’ term (55). Ne = An — On in which the accented letter is the epochal angle corres- ponding to the non-accented letter. But the resolving of a periodic oscillation under equation (1) is purely arbitrary, the periods being merely assumed instead of being known ‘‘apriori.’”’ In sucha case we may with some propriety regard the whole group of the second series of periodic terms as having what may be called a ‘‘oroup lag’’ in respect of the first series. It is obvious in the first place that the ‘‘ group lag’’ is a function of the epochal angles. Also, since the importance of any term varies with its amplitude, the influence of any epochal angle on the group lag must further be regarded as a func- tion of the amplitude factor. If then we suppose that the weight of each epochal angle enters into the result directly as the amplitude of the term, we shall have approximately for what may be called the mean epochal angle, _DVGAGH FT GpAoigticass aul Ouece) 5 8) 290 a a ‘ STUDIES IN STATISTICAL REPRESENTATION. 101 and the general lag will be Cf) seg == 0% — & 0. This expression which is empirical, however, loses significance as the similarity of the two curves disappears, and in any case can be regarded only as of the nature of a rough indication of the general time relation between them. 14. Analysis of sine and cosine curves:—When a curve is of the type of a simple sine curve, differing only in respect of absence of symmetry, it may be represented by (S72)... 4 = A +B sin «+ C cos « which is identical with is) 4 — A +b sin («+ 8) + ¢ cos (@ + y) since it is easily shewn that | (58)... B=bcos8 — csin y; and (58a)... C=—b sin 8+ © cos y. In all cases we have (59)... A= - 2h i If we put as before 7, = y,— A, we shall have for quadri- mestral division __ 2a(r,— £3) é ash Ry TY, , (60)... B= eis C= 33° for quarterly division (61)... B= a 2—-3—14)3 C= aint tat 1) and for division into five parts Ar 2/277 2)... B= —,—-1;); C= > — (6 ) B 95 +55 (ade T2—P4 Ts)3 C 5v(5 — V5) the coefficients of which may also be written 7/45(1 + cos 36°)? and 47/(5 sin 36°). Where the form in (57a)satisfactorily represents the data, it is occasionally necessary to determine the point where the curve has a maximum or minimum value or equals the average value (A). The points where y = A are given by B sin 6+ C cos ¢6=—0. 102 , G. H. KNIBBS. 6 being the value of x for y = A, that is:— C ad Oe. (63)... tan B: and the maximum and minimum values of ~, » say, are given by dy/dx« = B cos p — OCsin rp = 0, that is (64)... tan p =f= — cot 0. In comparing two curves of this type, we must have recourse to such corresponding phases as @ and p. The value of the ordinate at this point, viz. the maximum or minimum is | (G5)e5 4 — Ar vy eee. In other cases than that referred to, the determination involves the solution of an equation of the fifth degree, and need not be considered. Where there are more divisions than five it will in general be desirable to represent the frequency by an equation of the form (66)... y=atbsinx + ce cose +d sin 2% + e cos 2a, The integral of this is (66a)...fydex = ax—b cos « + ¢ sin « — $d cos 2x + fe sin 2x and if it be taken between the limits 0 to Ae 3 toss eters. and if y:, y2...denote the monthly means we have i=) +e {- b (cos 30° — cos 0°) + e (sin 30° — sin 0°) — $d (cos 60° — cos 0°) + § e (sin 60° — sin 0°)?, As before denoting y, —a by r,...we get a Series of equations of which the first is 5 1”, = b (cos 0° — cos 30°) + ¢ (sin 30° — sin 0°) + $d (cos 0° — cos 60°) + #e (sin 60° — sin 0°) Denoting 1 — a8 bym: “8 by! : and + by k, the 2 equations become gn=mb+hetdt dhe, STUDIES IN STATISTICAL REPRESENTATION. 103 the coefficients of b, c, d, e in the successive terms 1, 12, etc., being represented by the following scheme r b Cc ad e aD Cc d e Mantis oe sk To Hm) —-F ) t+ Ek meget lo oS 0 S ol =f 4 0 wo Wh Pak 2k 9 = am Eh mn. Wome Sook 10 =f) Pm s—b --4k em bm Oye A els pee bal eas 0 Mir ie 5 eek 12 =m at =e ak From these necessary combinations may be obtained for determining the constants b, c, etc. The most probable values of these constants may be obtained from the whole of the equations by making use of the method of least squares. Multiplying the equations in turn by m, l, $, etc., (i.e., by the different co-efficients of b) we obtain, since the sum of the co-efficients of c, d, e all total to zero, (67)... 5 fr, + Ur, + 4 ry +......1= 6 (2— v8) b. Similarly the following equations can be deduced (68)... = {4 m+ Ir t .... v= 6 (2— v3) ¢, CaF fen ttnt..j=s, “Ga and 7 . 3) #0)... m 4 bee Oo Pek {= 3 e. which give the values of b, ec, d, and e. In the case of the “‘ temperature curve’”’ already ex- amined, see § 11, 7, = 9°02: 17,—= 8°62, etc., and we derive the values a = 62°08; b = 3'227; ec = 8°965; d — 0°337; e= — 0°890. The second (small) co-efficients d and e denote merely small oscillations about the main curve defined by the first pair of co-efficients (large) viz., b and e. 104 G. H. KNIBBS. PEE EEE EEE € HEBBEREaea aN] HEBBEN pas SF AC 0 3450 HoaNOnNesoaey, i RECEP et T ECE SeUSNgae Db @hbca a? GER BERR RRRRREZe4200loL Ba on BRS VEER SHESS >SSSaR BS 4ORR DE IoSaaSSo50000. APE Let SSSR S0087.77 40005555 SCENE CET Peo eer StH PREECE COC Ae EESSEOEPONNSp; BRSSSEEae TA 28688080 GOO EEEEBSREDOSSESLSQb2uuNs (ea | aa | | a Hl J) y| a a A 7 Qj iY HEB a |_| a |_| H = H | a ot Z 7 a aT TN Hite eee: fe Oo [| a NE bases H - - i a r CCCCCEN SE Eeeceesatuansceee= ea CCC Vaile Be a Q |_| o wi NY LN | | |] B a a a a || | L- SEEEEETSESEEEEEETSEEEETTG®“auaTETeEEET=E CCCPRCCCEE Ee HHH Benner H H H 7. Seattiiiat “HFEEEE BESSARSESRSSOSOe — Soon! 4oneeo iZ |_| ele} Be | HH tte [| aE EE TT n SE ist [| [| | B : [aa mn a B Ag tH [eal - | [| a I PN’ +e Goa Jan Feb Mar Apr May Jum Jul Aug. Sep Oct. Nov Dec. For the suicide curve the co-efficients are :— | == 0°3291; = 0°0054; = 0°0285; = 0°0097; — 0°0064. It will be seen that the general trend is fairly well repre- sented by the sine and cosine in « only. In the diagram the different curves shew the following:— Curve 1—Suzcrdes. (a) The group results are shewn by firm rectangular lines. (b) The complete curve in sin « to sin 6x giving these group results is shewn by firm curved lines. (c) The curve given by sine and cosine of ~ and 2a by dotted » curved lines, STUDIES IN STATISTICAL REPRESENTATION. 105 The ordinates to the curve denote the number per diem per million committing suicide in the Commonwealth of Australia. Curve 2-—Suicides. (a) The curve shewn by firm lines denotes the solution in terms of sine and cosine « only. (b) The curve in dotted lines denotes similarly the solution in terms of sine and cosine 2x as well as x and shews the effect of the introduction of this second series. This is the same as the dotted line in curve 1, (c). The ordin- ates denote the number per diem per million committing suicide in the Commonwealth of Australia, but are plotted to a larger scale than in curve 1, (c) The curve in broken lines with dots is the suicide curve, as empirically deduced by formula (71) § 16 hereinafter, from the temperature curve 3a. Curve 3—Temperature. } (a) The curve in firm lines denotes the solution in terms of sine and cosine x only. ) (b) The curve in dotted lines similarly denotes the solution in terms also of sine and cosine 2x, as well as «x. Curve 4—Temperature. (a) The monthly means shewn by firm rectangular lines are obtained from the monthly means of the maximum and minimum temperatures of the capital cities of the States taken over a long series of years, weighted according to the population of the States. It may be considered as the curve of temperature affecting the population of the Commonwealth as a whole. (b) The firm line shews the complete curve in sin x to sin 6x giving the group results. (c) The dotted line shews the curve given by the terms in sine and cosine of « and 2z, only. 15. Periodicity affected by movable feasts.—The perio- dicity of marriage and of migration etc., is affected by the 106 G. H. KNIBBS. ‘““movable feast’? Haster. As ecclesiastically defined Easter day is the first Sunday after the 14th day of the paschal ‘‘ Calendar Moon,”’ a fictitious ecclesiastical moon, which is from one to three days later than the real moon (See De Morgan’s article in the Companion tothe Almanac 1845). The average position of Haster for the century 1800 to 1899 is April 8°55 days, and for the century 1900 to 1999 is April 8°89 days, or say for the whole period of 200 years April 8°72 days. In the illustrative figure herewith, the whole of the Hasters in each decade are shewn on a single line for the years 1800 to 1999 inclusive. It will be seen that an inspection of the diagram will disclose the fact that the points lie approximately on a series of 10 slanting lines, four days apart, these lines progressing at the rate of one half day per decade, and further that they are inversely symmetrical. For lines a, b, c, and e anda, 0’, ec’, ande’ the symmetry is perfect ; for linesd and d' however the symmetry is not absolutely perfect. It is evident that no means derived from two decades nor from periods of 19 years, nor from centuries are exactly comparable. Position of Easter. March April LEB wUBHWHITIASSTEIONL BMGT B22 LBW Te? ey GE me es | (CES) SRRSGEEDUL = 4] all STUDIES IN STATISTICAL REPRESENTATION. 107 Since the tropical year = 365°2422 days and the synodic lunar month = 29°530588 days, the Metonic cycle, *19 tropical years is 6939°6018 days, and 235 complete lunations equal 6939°6882 days, differing only °0864 day from the nineteen years. The following table exhibits the peculiarities for succes- Sive decades. Mean Position of Easter.* 1800. 1900. Easters|Mean of} Mean of | Easters Mean of| Mean of Decade. | Mean. in March} April | Decade. | Mean. in March | April March. |Easters} Easters. J March.|Easters | Easters. April April] 0-9 9°46 1 29 9:56 0--9 10°56 2 3075 13:12 10-19 | 816 3 25°67 | 13:57 | 10-19 | 8:36 3 27 12°86 20-29 8°86 2 28 11°50 | 20-29 8:06 2 29 10°25 30-39 7°86 3 2S 11°43 | 30-389 9'6& 2 27°5 12°62 40-49 | 9:06 2 25 12°50 | 40-49 8°96 2 26 12°12 50-59 8°56 3 27 13:57 | 50-59 7°56 2 27 10°38 60-69 | 796 3 28°67 | 11°86 | 60-69 | 9°66 2 275 | 12°88 70-79 9°36 2 29°5 11°88 | 70-79 8 66 3 28:33 | 13°14 90-89 | 946 | 2 25'5 12:62 | 80-89 8:66 2 28 11°25 90-99 | 6°76 2 27 9°25 | 90-99 | 8:76 2 30°5 | 10°88 Means | 8'55 2°3 27°48 | 11:70 | Means| 8-89 2°2 28:09} 11°94 —<—— * The complete cycle of Easter restoring both the day of the week and of the month is 4 x 7 x 19 = 532 years, the “ Dionysian” or “Great Paschal” period. To find the position of Easter day (Sunday) we have for any years subsequent to 1582 Y denoting the date (year of the Christian era) NV denoting the golden number # denoting the epact, or moon’s age at the beginning of the year (expressed positively) C denoting the number of centuries in the date | P denoting the number of days from the 21st March to the 15th day of the ‘‘paschal moon” L£ denoting the number of the dominical letter of the year To obtain a normal periodic fluctuation it would be pre- ferable, were it practicable, to combine the results, each for a series of years such as would give Easter an identical distribution. In the period such a series is, however, im- practicably long. Hence in the case of marriage, migration etc., we must consider the actual effect on the periodic fluctuation studied. The effect of Easter is to reduce the 108 G. H. KNIBBS, 1 denoting the letter belonging to the day on which the 15th of the ‘“‘paschal moon” falls p denoting the number of direction or number of days from 21st March to Haster day then a subscript 7 following brackets denoting that the remainder only is to be taken, and a subscript w in a similar position denot- ing that only the whole number in the quotient is to be taken, we shall have Revi (ss, : (CEN 19 25 N +10(N-1) C-16\ , (O=ise #=(— 3), (0-10) = aaa -¥ - (2), + (0-16) é (eo in which m is an integer such as will give a product not more than 6 greater than the number following in the brackets. o4 | Pe e24 = Ae a ozo WAT Oe les a | Mae sea sie Dei Hence the number of days from the beginning of the year is:— 81 + p for leap years, and 80 + p for common years : common years being such as are not exactly divisible by 4, or being divisible by 4 are also divisible by 100 but not by 400; excepting that ‘years divisible by 4000 are also common years. Leap years are years exactly divisible by 4, unless divisible also by 100 and not by 400; and further if divisible by 4000 they are common years, STUDIES IN STATISTICAL REPRESENTATION. 109 number of marriages in the Lent period (6 weeks) preceding, and toaugment them in the preceding and following periods. It may be noted that for the fluctuations of annual period in the marriage frequency, the great length of the Lent period, viz., 6 weeks, has the effect of throwing the increase of frequency as far back as February. The migration fre- quency is frequently thrown back into March. Thus as is evident from the preceding table and the diagram, decennial means will clearly be nearly but not exactly comparable. The data for a thorough study of periodic fluctuation would in these cases have to be weekly groups. 16. Connection between periodic series.—Correlation between statistical results may be of two kinds, viz., (a) rational, and (b) empirical. In the curves 2 and 3 in the figure, where the fluctuations of suicide and temperature are analysed by the expression in sin # and cos x only (which in the nature of the case probably really represents the general trend) the striking similarity is evident. That suicide is accentuated in the summer and falls off in winter, is thus indicated, and in the Northern Hemisphere the same holds, that is to say the maximum period differs about six months from that in the Southern Hemisphere. On com- paring the two curves in sin x and cos x only, we find the following results hold Temperature curve max. 71°61 at 19° 48’ min. 52°55 difference 19°°06 Suicide curve max. 0°3581 at 10° 44’ min. 0°3001 difference 0°0580 Since the mean for the suicide curve is 0°3291 and of the temperature curve is 62°08°, and since moreover 0°0580/19°06 = 0°00304 we have the suicide curve almost exactly pro- duced from the temperature curve by the formula (71)... g == 0°3291 + 0°00304 (¢ — 62°08’) 110 G. H. KNIBBS. in which q is the frequency of suicide per diem per million in the Australian Commonwealth and ¢ is the temperature in Fahrenheit degrees. This curve is plotted as curve 2 (ce) and it will be seen from the diagram, that if it be moved about 9 or 10 days to the left (19° 48’ - 10° 44’ = 9° 04’) it is practically coincident with the temperature curve. This identity is purely empirical. The discussion as to whether this relation can be rationalised is really an extra-mathe- matical one, and is outside the scope of the present paper. 17. Conclusion.—The formulee given for deducing the constants of the several equations will enable periodic series to be conveniently applied to the discussion of appropriate statistical results, without involving a prohibitive amount of labour, and will yield expressions that reproduce the data exactly, while giving instantaneous values through- out their whole range. The illustrations are intended only to exhibit the mode of application of these formule. ECHINORHYNCHUS POMATOSTOMI, N.SP. ja ECHINORHYNCHUS POMATOSTOMI, (N.Sp.) A SUBCUTANEOUS PARASITE or AUSTRALIAN BIRDS. By T. HARVEY JOHNSTON, ma, DSc, and’ J. BURTON CLELAND, M.D., Ch.M. (From the Government Bureau of Microbiology, Sydney.) [Read before the Royal Society of N. S. Wales, July 5, 1911.) In three species of Pomatorhinus and in three other Aus- tralian birds which were associated in each case with members of this genus, a number of larval individuals of a species of Hchinorhynchus was obtained by one of us from three different portions of Australia, each separated from the other by a distance of many hundred miles. As the occurrence of larve of this genus in vertebrates is rare, and is so far unrecorded for Australian Birds, it seemed to us advisable to describe this parasite as fully as the material willallow. From its association in each case with members of the genus Pomatostomus (Pomatorhinus), we have given it the specific name of HE. pomatostomi. The following information as to the discovery of these parasites may be interesting more especially to those ornithologists who have facilities for examining fresh carcases of Aus- tralian birds. In the latter part of the year 1907 one of us had an opportunity of securing some birds midway between Port Hedland and Marble Bar in North West Australia. On one occasion Pomatostomus rubeculus, Gould, and Climac- teris wellsi, Grant, were shot together in the same patch of scrub on the banks of a dry water-course (the Shaw River), together with a few other birds. On preparing the skins later, a number of small white bodies like very small 112 T. H. JOHNSTON AND J. B. CLELAND. grains of rice were found embedded in the subcutaneous tissue of the necks of these two birds. These were easily shelled out and then proved to be small larval worms. In May, 1910, about twelve miles south of Adelaide Pomatos- tomus superciliosus, Vig. and Horsf., and Aphelocephala leucopsis, Gould, were shot near the same patch of scrub together with several other small birds anda hawk. In the Pomatostomus and Aphelocephala were a number of larval worms similar to those in the North Western birds, distributed in the subcutaneous tissues of the neck and thorax, sometimes being more deeply placed between the muscles especially those of the chest or even within the muscles. In November, 1910, two specimens of Pomatos- tomus frivolus, Lath. (syn. P. temporalis, Vig. and Horsf.) together with several other birds were shot near Collar- enebri in the north of New South Wales. Both the Pomatostomi showed scattered larval worms in the same situations asin the birds obtained near Adelaide. The country here was open black soil plains with a few scattered | gum trees. We have recently received from Mr. J, W. Mellor through Mr. L. Harrison, a number of similar para- sites from the subcutaneous tisssue of Hylacola pyrrhopygia, Vig. Horsf., shot near Adelaide. It will be seen from the foregoing, that this small parasite is widely distributed geographically in Australia, having been obtained at three places sundered by many hundred miles from each other. Lines joining these three points would form roughly a triangle with its apex in Southern Australia, one angle in North Central New South Wales, and the other angle in North West Australia. The types of country of these three localities are absolutely distinct from each other, so that no particular type of country can have much influence on the development of the parasites. It is a significant fact that in each of ECHINORHYNCHUS POMATOSTOMI, N.SP. 143 the three localities birds of the genus Pomatostomus were infested. Several hundred birds have been examined by us from various parts of AuStralia, but the parasites have not been detected in any of these save in those above mentioned. It therefore seems highly probable that the ordinary host ‘for the larvz consists of birds of the genus Pomato- stomus, and that these have been the dispersing agents. throughout Australia, but that occasionally other small birds such as Climacteris, Hylacola, and Aphelocephala, living in the neighbourhood of Pomatostomi can also harbour the larve. It may be presumed however that the infestation of these other birds is more or less accidental, and that from their habits or the nature of their food, they do not so readily acquire the ova as does Pomatostomus. - If many species of Australian birds acted as the ordinary host of the larvee we would have expected to find more instances of invasion in other species, and also cases of birds being infected in neighbourhoods where Pomatostomus was not present. It will be interesting to see whether species closely allied to this genus can also act as distri- buting agents. If any such birds are found to act in this. way it would support their position as relatives of the genus Pomatostomus. It is possible that the adult worm may be: an inhabitant of the intestine of some birds of prey, and that in this way the life cycle is completed. The parasites usually resemble small maggots, about 3°33 mm. long, with a maximum breadth of about 1°26 mm., the surface of the body being transversely wrinkled. The posterior end is bluntly rounded, the anterior extremity being truncate and rather wider. Retracted within the latter lies the rostellum. The lemnisciare nearly 1°25 mm. in length. No other internal structures are recognisable. In one specimen (taken from P. superciliosus) the rostellum is everted, the worm being fully twice as long as the form H—-July 5, 1911. 114 T. H. JOHNSTON AND J. B. CLELAND. usually met with, reaching 7°4 mm., but its maximum width is only 0°93 mm. _ In this specimen the cuticle is quite smooth. There isa gradual tapering towards each end, the posterior end being rounded off, while the anterior terminates in the prominent rostellum. The latter is 0°74 mm. in length (measuring the whole eversible portion), and 0°55 mm. in width. The hook-bearing part is practically spherical, a somewhat narrower neck succeeding it. The hooks appear to be arranged in eight transverse rows, there being about forty altogether. ‘Those situated anteriorly are much more powerful than those located further back. Kach is surrounded by a kind of collar which projects prominently around the basal region. These hooks, which may reach 0°205 mm. in length, beara marked resemblance in general shape to those of the large Taeniae. The dorsal root is short but thick and rounded, the ventral root being relatively massive. The claw or blade which is the only portion seen in ordinary preparations, is also prominent. On its inner side near the tip, there is a distinct notch or barb which no doubt adds considerably to the adhesive power of the hook. The type slide of Echinorhynchus pomatostomi (from Pomatostomus superciliosus) will be deposited in the Australian Museum, Sydney. EXPLANATION OF FIGURE. Echinorhynchus pomatostomt. Fig. 1. Usual form with rostellum retracted, from Pomatostomus frivolus. Fig. 2. Specimen with rostellum protracted, from P. rubeculus. ig. 3. Hook from rostellum, from P. rubeculus. Fig. 4. Portions of hooks from (a) Anterior series; (6) middle series; (c) posterior series, drawn to same scale— showing collar—from P. superciliosus. AppENDUM.—In May, 1911, one of us obtained further speci- mens of this parasite in Pachycephala gilbertt, obtained near Blanchetown in South Australia. Pomatostomus was in the neighbourhood. 116 E. C, ANDREWS. EROSION AND ITS SIGNIFICANCE. By H. O. ANDREWS, B.A., Department of Mines, Sydney. [Read before the Royal Society of N. S. Wales, August 2, 1911.] Introductory: THE present note is an attempt to coordinate our know- ledge of stream processes, and to assign them their proper place in the sculpturing ofland forms. It is rapidly coming to be seen that in order to explain the origin of certain common but important “‘facts of form’’ one must grasp the real significance of the operation of certain highly variable factors, not only when acting individually but also when acting in combination. To take a single illustration, it is well known that wherever there are high plateaus in the temperate and tropical regions there one finds great fault scarps, deep narrow senkungsfelder,* and great numbers of minor fault scarps, arranged apparently in the most capricious fashion. On the other hand similar plateau blocks occur in the mountains of Western America, in Alaska, in southern New Zealand, in the Swiss Alps, in Norway and in the Antarctic, and it is almost certain from a consideration of mechanical principles, that in these regions also deep senkungsfelder were formed, nevertheless the intense glaciation to which they have been subjected in more recent times has so modified the preglacial profiles as to obscure them and to make it almost impossible to directly prove their origin by faulting, by stream action, or by a combination of these two activities. It is a remarkable fact, however, that so soon as one leaves the region of intense glaciation in such areas, one has the evidence of strong recent fault- 1 A senkungsfeld is a sunken, or dropped, block of the earth’s crust. EROSION AND ITS SIGNIFICANCE. 137 ing [e.g. Colorado, Utah, Arizona, and California]. To the case of the New Zealand Alps and the Californian Sierras reference will be made later. A personal experience may perhaps be of interest in this connection. During a great number of cross-country journeys undertaken some years ago in New England (New South Wales), the writer had observed the existence of a magnificent plateau level varying from 3,000 to 3,400 feet in height. One peculiarity of this grand land surface lies in the fact that it is separated into a northern and a southern portion by a plateau about 1,000 feet higher, the two surfaces being connected by long rambling spurs whose bases are not arranged after any regular pattern. Further- more, wherever examined the lower plateau was observed to be dissected by very broad and shallow valleys, as to its central portions, and by deep profound canons on its eastern (and western) portions. Various other plateau remnants also diversified the main surface, their heights varying from 200 to 1,200 feet above the general level. Ridges and peaks likewise rose from these higher plateau blocks. The walls of the broad plateau valleys were rarely rectilinear, but were interrupted by jogs and large re-entrants. Inthe year 1903 these surfaces were described as the products of several cycles of erosion.* In 1908 the writer accepted an invitation from Dr. G. K. Gilbert to visit the Sierras of California in connection with the question of the efficiency of ice as a powerful corrasive agent. The trip was carefully planned by him soas to lead _ the observer gradually toa scenic and physiographic climax in the Yosemite National Park. The way led first across the Great Californian Valley to Shafer via Fresno, thence up a fork of the San Joaquin tothe Upper Evolution Valley * «Tertiary History of New England,” Rec. Geol. Surv. N.S. Wales, 1903, p. 140, 118 E. C. ANDREWS. and to the summit of Mount Darwin (13,870 feet). The descent thence was made of the great east fault front of the Sierras. The base of this giant scarp was then skirted to Mono Lake. The Sierras were here ascended at Bloody Oanon. Mount Dana (13,000 feet) was visited, and the Yosemite was approached by way of Tuolumne and Cloud’s Rest. Trips also to the Grand Canon of Arizona and to the Wasatch Range of Utah were taken at Dr. Gilbert’s suggestion, and Pike’s Peak and Cripple Creek areas were also studied. To Dr. Gilbert, our master in physiographical — science, the writer is under a peculiar debt of gratitude for the trouble taken by him in pointing out all points of interest in this wonderland, and for supplying an explana- tion of the greater “* facts of form”’ there seen. The general account of the wonderful topographic and volcanic forms seen on that trip will doubtless be written by Dr. Gilbert and Mr. Willard D. Johnson who have both made a close study of them. As a result of that trip the writer wrote a paper on ‘‘Corrasion by Gravity Streams.’’’ But after the prepara- tion of that paper it was seen that the application of the principles therein deduced suggested the complete dis- mantlement of one raised peneplain surface during the development therein of another peneplain at a lower level, if both such surfaces had been excavated in rocks compar- able in hardness and resistance to the forces of erosion. This leads to the main thesis of the present note, namely, that in areas of homogeneous rocks or of rocks comparable in hardness, such as dense sandstones, quartzites, granites or crystalline schists, the existence of two peneplain sur- faces in association but separated by youthful topography must be explained by activities other than those of ordinary corrasion.” ? This Journal, Vol. xxiv, 1910, p, 204. * A joint paper on the physiographic criteria of faulting in Eastern Australia is in preparation by Mr. C. A. Stissmilch and the writer. EROSION AND ITS SIGNIFICANCE. 119 It was evident after the production of this note on cor- rasion that although the main plateau level of New England and the broad mature valleys in the main plateau level and the mighty canons dissecting them might be referred to the forces of erosion, nevertheless the various levels lying above the great lower plateau surface must be explained in some other manner. It may be stated, however, that when the earlier papers on New England were written, such explanation of origin as is there outlined was in harmony with the conceptions of modern physiographers. Land Sculpture by Streams. Scope of note.—An attempt is here made to present in briefest outline the various steps in the formation of the peneplain, and then to make several important applications of such reasonings to geological problems. | The following notes do not conflict with the published views on erosion by Gilbert, Powell, Davis, Penck, Dutton, Lawson, Tarr, Salisbury, and others, but seek simply to add to them and to call attention to the important conse- quences of accepting such principles. The forces of erosion.—Let us consider the reduction of a high mountain or plateau mass by the forces of erosion, the action of the sea being neglected in this connection.’ On the one hand we have a plateau or uplifted plain, either high or low, either simple or complex in rock struc- ture, either simply warped or intensely faulted, either resistant or weak. Such a feature is evidently a challenge to the forces of erosion. On the other hand as destructive forces we have the action of gravity in bringing streams down to the lowest points of a region, and we have still * The action of the sea appears to be very limited unless helped by relative subsidence of the land. This is easily seen from a consideration of the slight depth only at which wave base can be developed below sea- level, and the slope of the profile of the shore thence to the shore-line, along which the sea must possess strength sufficient to transport its burden as a whole. 120 E. C. ANDREWS. another action of an insidious nature, gradually breaking down the chemical and mineralogical structures so that the action of the descending streams may be hastened. These are the forces of corrasion and of weathering, the former being dependent upon the transporting power of the streams. The attack of the streams themselves on the rock structures (corrasion) may be considered as analogous to a direct muscular assault in the animal kingdom, while the effects of weathering on the rocks may be taken as analogous to the diseases among animals. It will be seen that the corrasive attack is the dominant one in the earlier stages of peneplanation, while the attack by weathering is the dominant one during all but the earlier stages of land reduction. Special attention is directed to these processes. Transportation.—Geikie and Gilbert both insist on the geometrical increase of transportation upon simple increase of velocity for the case of ordinary streams. We quote first from Geikie (Geology 1893, p. 380). “Mr. David Stevenson’s table of power of transportation of different velocities of river currents. Inches per Miles per Second. Hour. 3 0°170 Just work on fine clay 6 0°340 Lift fine sand 8 0°4545 Lift sand coarse as linseed 12 0°6819 Will sweep along fine gravel (24 1°3638 Will roll along rounded pebbles one inch in diameter 36 2°045 Sweep along slippery angular stones size of egg.”’ ‘““The effects of abrasion upon the loose materials on a river bed are but a minor part of the erosive work per- formed by the stream. A tayer of debris, only the upper ‘portion of which is pushed onward by the normal current, will protect the solid rock of the river channel which it EROSION AND ITS SIGNIFICANCE. OA | covers, but is apt to be swept away from time to time by violent floods.’’—(Geikie, Geology, p. 385.) ‘*More work may thus be done by a stream in a day than could be accomplished by it during years of its ordinary condition.’’—(Ibid., p. 381.) The case however for ordinary streams was first stated scientifically by Gilbert in 1883 (The Topographic Features of Lake Shores, U.S. Geol. Survey, Fifth Ann. Report, 1883-4 p. 89). “*. . . It gives to the exceptional flood a power greatly in excess of the normal or annual flood. Not only is it true that the work accomplished in a few days during the height of the chief flood of the year is greater than all that is accomplished during the remainder of the year, but it may even be true that the effect of the maximum flood of the decade or generation or century surpasses the combined effects of all minor floods. It follows that the dimensions of the channel are established by the great flood and adjusted to its needs.’’ ‘ Floods.—This leads us to a definition of the term flood. It is common to hear of “ floods”’ inrocky mountain gorges, of the “‘sheet flood erosion’’ of broad valley bottoms and the ‘‘floods’’ in areas of deep alluvium. It is evident that two distinct processes are here implied, the one implying corrasion, the other bringing about an actual deposition of material. Weare here mainly concerned with the mean- ing of the term flood as it is related to corrasion, never- theless both cases are considered. In physiographical studies the term corrasion implies the mechanical abrasion, quarrying and sapping of the sides and the bases of stream channels; that is, the corrasion of channel structures implies ‘‘work’’ done on them by external forces. For channel structures, such external forces arise as the result of stream action. It is thus evident that.a stream which moves the upper layer only of the débris in its channel is not attacking the channel structures, but on the other hand the débris in such a case actually protects its channel profiles. Stated in terms of mechanics, then such a stream is not doing ‘work ’’ on its channel structures. Thus a glacier which overrides its ground moraine, or an ordinary stream which enters a deep hole in its course without stirring the pebbles and boulders at the bottom, ora torrent which forms a great alluvial fan on the floor of a senkungsfeld are all magnificent examples of streams which at such points are not corrading but are aggrading their channel structures. fe) E. C. ANDREWS. In periods of great stream volumes in mountainous areas the channel débris overlying any particular point is carried over that point asa whole, while during a period of “‘fresh’’ or ordinary “ flood’’ the channel débris is only moved as a whole in a few places. In times of such moderate stream volume the débris in the deeper holes and on the edges of the larger cutting curves is not moved as a whole, and the stream accomplishes but little work on the channel struc- tures. The word flood may then be defined in terms of mechanics for mountain tracks; in the case of the rock channel it is that stream volume which accomplishes ‘‘work’’ on its channel sides and base by moving the channel débris as a whole over any point of such channel structures. In this case the curve of corrasion is concave to the sky. The time factor is here not taken into consideration. A stream again in its course of development may have been affected by the development of a deep senkungsfeld across its path. In this case it will attempt to construct a bridge across the senkungsfeld along which it may trans- port its load. Thus the senkungsfeld base becomes heavily aggraded. In this case, even during periods of heaviest flood, corrasion is only accomplished on the upfaulted block while the downthrown block isactually protected. During EROSION AND ITS SIGNIFICANCE. 123 the heaviest flooding the débris will be arranged on the senkungsfeld area in a continuous curve convex to the sky. Smaller floods will destroy the uniformity of this convex curve. Sucha phase of stream action is usually very short. lived. Thus the term ‘“‘flood’”’ is seen to possess a dynamical significance for both degrading and prote@tive stages. It is necessary thus to carefully examine present day stream channels to understand whether they become flooded or not at periodical intervals. For only by appreciating the action of a flood can the formation of a stream channel be understood. To understand the work of the Upper Amazon in flood, one shouid have knowledge of it during such period or at least one should have knowledge of other large streams when in flood. Again, if glacial cirques are stream channels, then they in turn must have been formed during periods of greater ice volume than at present, because the “‘Ice Age’’ has only just gone, and the high level glacier marks may be seen on the cirque walls. But. to-day the ice in such situations is relatively meagre in volume; itisina state of tension, whereas in channels. formed by streams, the streams themselves should have been in a condition of compression when accomplishing their task. This arises from the conception of flowage by pressure as weight. All the foregoing account of flood action is dependent on. the condition that fioods are of such frequent occurrence that weathering has no opportunity to obliterate such flood profiles by its action during interflood periods. Form of channel.—It is evident that the stream corrades. hot so much by its own material as by the load of earth débris it transports, unless indeed its own mass is so great as to exceed the ultimate crushing strength of the rock structures it traverses or so as to be enabled to detach 124 E. C. ANDREWS, rock masses from their unstable moorings on declines. It is also evident that a stream must so work as to be enabled to handle its load in the easiest manner, so as to minimise friction and nevertheless so as to take the line of quickest descent. To handle its rock load as a whole, the stream volume must greatly exceed that of its load. The stones ‘by their superior weight will also occupy the more basal portions of the streams. The individual pebbles and other ‘classes of channel débris will all attempt to take the line of quickest descent, but from considerations of friction and transportation the channel can not be V-shaped. On the other hand the stream is forced to concentrate its volume as much as possible, so as also to minimise friction. Inas- much then as the stream load is small as compared with the stream volume, as the stream channel is designed so as to minimise friction, and as the streams take the lines of quickest descent, so the channel floor, in homogeneous structures as a whole, must be flattish nevertheless possess- ing a gentle slope to one deepest point, and its sides must be steep as compared with the floor. The reason for the last condition is plain. The individual boulders and pebbles of the load by minimising of friction tend to roll smoothly over each other, and yet to occupy only a small portion of the stream volume. They thus abrade the rock structures and form a flattish floor and sap the walls of the channel which are also abraded in a minor degree by the sand and smaller pebbles of the higher flood waters. The width and ‘depth of a stream channel are thus functions of the volume, the velocity, and the load of the stream. This applies in the main to all streams alike. Thus if a glacier has exca- vated a valley as its channel, and such channel be examined at a moderate distance from its head then its base may be wide and fairly flat. If now the slowly moving glacier disappear and a much smaller mobile waterstream occupy its valley, then the new stream cannot occupy the whole EROSION AND ITS SIGNIFICANCE. 125. glacial floor from considerations of volume and friction, but “will excavate asomewhat similarly shaped channel in its. floor as opportunity offers. Depths of canons in plateaus.—If one knew the details of stream corrasion well, then having given the volume, the load, the steepness of the thalweg, and the strength of the rock structures acted upon, one could tell to what exact depth the streams could cut their bases into any plateau. For it is evident that the channel bases will be eut down towards base level so long as the stream is. enabled to carry its load as a whole over its channel struc- tures. In the absence of such exact knowledge it may be helpful to describe several canon types :— In Eastern Australia a peneplain has been raised in late geological time to forma high plateau. In this surface streams such as the Shoalhaven, Hawkesbury, Olarence and Barron have cut gorges, and they may be seen to be still growing by headward recession. The Tallong Plateau through which the Shoalhaven flows. is 2,000 feet in height, and 50 miles from the sea the gorge of the stream is 1,600 feet in depth. The Wollondilly, at a distance of 200 miles from the sea flows in a gorge through a plateau 2,600 feet high, yet its base is only 600 feet above sea level at this point. The Barron is an extremely short river possibly not more than 60 or 70 miles in length. It has recessed its front for a distance of about 10 or 15 miles. The base of the gorge under the giant waterfall (750 feet) where it leaves the upland is said to be only about 200 feet above sea level. Similarly for other streams of Hastern Australia. The Merced Gorge in California flows through a lofty plateau for many miles, nevertheless at El Portal, its base is only 1,850 feet above the sea. 126 E. C. ANDREWS. The Colorado River at El Tovar, Arizona, flows through a plateau 7,000 feet in height, yet the base of the gorge is only 2,500 feet above the sea. Numerous other examples might be cited in illustration. In all these examples it may be seen at a glance that the streams are still able to carry their loads as a whole easily over their channel bases when in flood. In each case the channel structures consist of dense rock structures. In other words, provided the rainfall in these regions does not sensibly decrease in amount, the streams under con- sideration will cut their bases much more closely to sea level before they become incompetent to carry their loads asa whole over any given point of the fresh rock structures of their channel bases. Transitional stage.—But for all streams a slope of channel base is reached at some time along which the load that is delivered to the main channel cannot be moved as a whole over any specified point of the channel base, even during periods of heaviest stream volume. This stage at which the corrasion of fresh rock structures ceases to be the dominant factor in peneplanation may be called the Transitional Stage. Henceforth weathering and transpor- tation become the dominant factors in land sculpture by erosive processes. Width of canons.—Tributary streams cut their way into the plateau at the same time that the main stream does. In the early stages these side streams will be hung up.* By the repeated branching of such streams, the plateau in the vicinity of the main stream becomes riddled witha network of gorges. In hard rocks, such as granites, the writer has observed that the lips of the canon are about one mile broad when once the canon exceeds a depth of ‘ E. C. Andrews, Ee Linn. Soc. N.S. Wales, moe Vol. xxxI, pp. 419 —516. pl. xl, EROSION AND ITS SIGNIFICANCE. 127 1,500 feet. Exceptions to this rule occur near the heads of the gorges, where canons 1,500 feet deep are not much more than 200 or 300 yards across at their brinks. Ata considerable distance downstream the canons may become much wider, sometimes attaining a width of 10 miles, and nevertheless retaining their marked canon characters. Sapping and the action of storm waters have been credited with most of the work of canon widening. The examination of an ordinary side thalweg in such a canon, and which receives only the drainage of the canon side, is interesting however in this connection. In areas of dense geological complexes acted upon by a considerable rainfall, the floor of the channel will be found to consist of steep rocky ledges and waterfalls, here and there cumbered with heavy rock fragments. The whole stream course thus bears signs of extreme youth. To leave the thalweg involves a scramble or a difficult climb up an excessively steep spur to the sides of which cling ferns, shrubs, jungle growths or even great trees. The rocks are much shattered, granite blocks may be easily detached; they appear to have been wedged apart; slates creep; and fresh scars of land and rock slides are common, the latter showing the influence of great master joints. Notwithstanding all this the spurs are frequently heavily grassed, and their crests are often con- vex to the sky. At the headwaters of the thalweg, that is, at the angle where two spurs meet at the lip of the canon (or at a point down the cafion side) an amphithea- trical enclosure may be seen often of appreciable size. Here there is no catchment for rain waters, the rocks are seen to be rotten, slates creep when present ; the material is weathered, and by sapping from corrasion at a point some distance down the thalweg the gravitative or amphi- theatrical head is formed by the action of material falling freely towards a Common point. This amphitheatrical ' Bi ~ 128 E. C. ANDREWS. head slopes downward to a narrow and steeply inclined thalweg. This then, the force of weathering, becomes a great factor in peneplanation when once the transitional stage has been reached. For the channel structures of the deep valley bases are attacked by the insidious force of weathering and lose their coherence, and thus the streams which could not corrade the fresh rock structures are enabled to gradually transport their weathered fragments. The important point to remember about this is that once the transitional stage has been reached, henceforth the signs of youthful topography gradually and continually decrease, never more to be revived unless by some much more potent stream action or by some powerful earth movement. Corrasion above the canon walls.—lIf a peneplain be slightly tilted as well as locally faulted or sharply flexed, then two valleys will be carved out of the upland at the same time, one a cafion receding from the face of the fault or flex, and one a broad and shallow valley formed head- wards of the canon growth. For during the peneplain stage which preceded the uplift, weathering activities extended to considerable depths below the peneplain surface, but the streams could only feebly transport such weathered material during the advanced old age stage of erosion. Upon slight tilting of the uplifted peneplain, however, the streams. would have their velocity increased sufficiently to corrade this weaker material, and thus a broad and shallow valley would extend headwards of the canon growth. Hvenif the plateau were not tilted, the very excavation of the canon would yield enough stream fall to enable a new valley to be formed in the weathered material above the falls. Such a valley will necessarily become rapidly mature and will usually be very shallow indeed owing to the downward limits set upon effective weathering. EROSION AND ITS SIGNIFICANCE. 129 The canon will recede along this shallow mature valley and in the divide it will assume a fairly broad amphithe- atrical shape, the depth and breadth of the form so pro- duced being strongly influenced by the height of the plateau, and both by the rainfall and the distance of the divide from the sea or from the nearest heavy fault or flex scarp. At the actual divide the curve of the surface should be convex to the sky, because in such places weathering runs ahead of corrasion—because of lack of catchment area—and the material tends to sink down hill under both its own weight and the influence of rains, thus tending to the parabolic curve convex tothe sky.* This feature needs attention to be directed to it, inasmuch as it illustrates the influence of weathering, even in this early stage in plateau dissection.” Subsequent stages of reduction.—The incapacity of the stream to directly scour its fresh rock structures at a cer- tain definite critical stage (varying in time from point to point in its history) is not so much because of the absolute efficiency of weathering processes, as that the streams have reduced the slopes of their thalwegs to such an extent that their velocities in turn have been much reduced. This again implies an almost incredible decrease in power of transportation, and this it is which furnishes the real check to the initial rapid corrasion of the uplifted peneplain. The influence of such a factor on the rate of sedimenta- tion will be dealt with later. This stage when weathering is so powerful a factor, and when lateral wear is in excess of vertical wear, is probably that which Davis describes as ‘“‘the balance between erosion and deposition,’’* and that to which Gilbert’ refers in his statement “‘that downward wear ceases when the load equals the capacity for transportation.”’ + Corrasion, p. 216. ? Convexity of Hill Tops, G. K. Gilbert, Journ. Geol. 1909, pp. 340 — 350. $ Journ. Geol,. 1902, pp. 86-87. * Henry Mountains, 1877, pp. 126-127. I—August 2, 1911. 130 E. C. ANDREWS. It must, however, be distinctly understood that though the stream has now no opportunity (except on narrow ridges) to effect much corrasion of live rock structures, nevertheless, as the rocks themselves become broken up by the action of the weather, so little by little the stream removes the incoherent mass so produced towards the sea. Thus the channel bases ever approach the main sea level. Because of the relative greater relief of the interstream areas, however, the latter will be more rapidly worn down to the general level of reduction by erosion than the main channel bases themselves. Thus the country tends ever more and more to the plain stage, and the youthful topo- graphic form becomes less and less possible. The convex profiles which characterise the actual crests, even in the youthful stage of dissection, ever grow wider and wider, and become ever more and more important features of the landscape, until, as in the case of the majority of the inland country of New South Wales, the summits of the gentle hill slopes can only be seen from points at some distance from their bases owing to their convexity of slope. This is the slow aggradation of the hillside, owing to the. supremacy of weathering agencies over those of corrasion and transport. Davis’ vivid picture of the death of the plateau shows how its features diverge more and more from those of youthful attack.* It may be noted, however, that in sub- arid New South Wales, as at Cobar, numerous narrow and steep ridges or peaks with steep rocky thalwegs dot the great plain of denudation. These represent the action of fierce thunderstorms on resistant rock ridges in an area which is not much influenced by weathering. We have then by this slow but fairly safe route reached the following important conclusion :— 1 Journal vf Geology, 1902. EROSION AND ITS SIGNIFICANCE. 131 Whenever two peneplain or [old age] surfaces are found associated in resistant rock structures, such as granites, crystalline schists, and dense quartzites or sandstones, and the two such surfaces are situated the one above the other, and the two are separated by a youthful or mature topo- graphy, it may be considered that they were formerly continuous, but are now discontinuous, owing to earth processes other than those due to erosive activities. Such earth processes may be either warping or faulting. This is absolutely irrespective of any irregularity of plan possessed by the youthful topography separating the two peneplains. Applications. Several important corollaries may now be deduced from the main principles of stream erosion :— (1) Height of peneplain above sea level. The profile of corrasion in the ideal case is a function of stream volume. At each point corrasion varies both as the stream volume and as the cube of the velocity thus derived. The thalweg may be considered as receiving equal increments of volume at points equidistant from each other. These produce a definite increase in velocity, but this in turn implies a much higher increase in kinetic energy. Therefore the profile of corrasion should steepen with relative rapidity as it is traced headwards. After the limiting profile of corrasion of fresh rock struc- tures has been formed, weathering ensues and the work is carried on by transportation of the rock material thus broken down. There is practically no limit to this action. The final stages of corrasion, however, will apparently bea low plain generally convex to the sky and not much raised above sea level. The convexity of profile to the sky will be assumed long before the reduction of the surface to very low levels, and a peneplain may well be conceived as having 133 E. 0. ANDREWS. a general height at its centre of several hundreds of feet, provided the divide be situated at a considerable distance from the sea. ! (2) Computations of the age of the earth based upon the estimated rate of denudation at the present day. | It is common to find the age of the eartb’s sedimentary record based on the assumption that denudation of the land occurs at a fairly uniform rate.* The study of erosive processes does not bear out such assumption for the following reasons :— (a) The mountains of the present day are doubtless com- parable in size with those of any Post-Archean Age. | (b) The mountain valleys of the present day are quite youthful, and their loads are enormous by reason of their great transporting and corrasive power. Such transporting and corrasive power is related in a rapidly increasing geometrical ratio to the simple increase of stream velocity. (c) Mountains are only transient forms in a landscape during the cycle of erosion necessary for the production of a peneplain. ! (d) The time necessary to reduce a continent or plateau from a height of 1,000 feet toa peneplain of 500 feet in height at its centre involves practically the same length of time as the reduction of a plateau 20,000 feet in height toa similar stage when all other things are equal. This is simply an application of the known laws of geometrical decrease of corrasive and transporting powers upon the great reduction of stream channel and land slope. : (e) Many great peneplains or surfaces or erosion have been formed at various periods in the earth’s history. It would thus appear that estimates of the earth’s age based on the assumption of uniform denudation are altogether too small. 1 A. R. Wallace, Island Life, 1892, pp. 210 - 240. EROSION AND ITS SIGNIFICANCE. 133 Hstimates of the earth’s age from a consideration of the thickness of the sedimentary deposits are also valueless for a similar reason. : | ; _ Estimates also as to the earth’s age based on the salinity of the ocean apparently need modification, because all the: factors do not appear to have been considered. Thus dur- ing an ephemeral mountain period, such as the present one, the volume of rock accessible to wandering waters which yield up their harvest of salts to the rivers is much greater than that during the incomparably longer life of the low lying plain of erosion. (3) Peculiarities of certain topographies.—Controversy has raged round the origin of certain topographic features for many years. Thus the Yosemite Valley of California has been explained variously as the result of stream, of fault, or of glacial action. The fiord and lake basins of New Zealand have also been explained in the same manner, so also the forms of the Scottish Highlands, of the Nor- wegian fiords, and of the Alpine valleys and lakes of Switzerland. While all these processes have doubtless been active in all the regions mentioned during recent times, it is necessary to decide as to what share each has had in moulding the landscape. In this connection brief mention only is made of the Yosemite and several New Zealand forms. Yosemite.—It is certain that glaciers have occupied the lower 2,000 feet of the valley in recent time and it is highly probable that they have produced the peculiar ‘“‘steps”’ and ““treads’’ at the Nevada and Vernal Falls. On the other hand there are no moraines in the valley worth serious consideration, and the upper valley slopes are certainly those due to sapping action. The most difficult thing to explain on the assumption of the origin of the Yosemite profiles by ice corrasion alone is the position of the Bridal Veil Falls and the peculiar re-entrant in the wall immedi- ately downstream of El Capitan (See Matthes’ Topographic Map). On the other hand this part of the valley could be easily explained by faulting action with later modification by ice-stream action. An interesting fact of observation in this connection is that the Yosemite Valley lies in a region of intense faulting and warping action in late Ter- tiary or recent time. Glacial action, however, has certainly exercised a marvellous influence on the preglacial Yosemite profiles. 134 E. C. ANDREWS. _ Preservation Inlet, [New Zealand].—Here a long broad and fairly shallow inlet dotted over with islands runs up along its lower portions into a plateau about 1,000 feet in height, while its upper portions run amongst much higher plateau remnants. The various topographies thus enumer- ated are separated by rough youthful forms. Heavy glaciers have passed down the inlet or sound, leaving moraines and other signs of ice action in various places. Tbe most feasible explanation (from a consideration of the present note) is that earth forces raised a peneplain here in recent times to form two high plateaus and dropped a centre block to form the inlet, which has since been modified by ice erosion. Lake Te Anau is a large body of water bounded by plains and lake terraces on the south and south-east, while its western and main eastern walls are composed of high plateaus of varying heights, and trenched by three or four profound fiords. The base of the lake lies many hundreds of feet below sea level. The topography to the west and north-east is singularly wild, rugged, and magnificent, while the approach from the south is tame and monotonous, except for the high and rugged Takitimu Range which bounds this low lying land block to the east. EROSION AND ITS SIGNIFICANCE. 135 On the same wide and low lying block as that which holds Lake Te Anau lies Lake Manapouri, and both lakes have their deepest portions in situations along which the greatest stream scour could not have taken place. On the other hand the locations of maximum stream (ice or water) scour have been along channels whose bases lie above or near lake level. Ina word, the lakes lie on an old age surface, and such wide surface is separated from other dismantled old age surfaces by the wildest topography imaginable. The region has been intensely glaciated in recent times. It is difficult to assign the exact share that earth move- ments and erosive activities have had in producing this magnificent topographical feature, but it is evident that corrasion has had only a minor share in producing the total result. The lake in quite recent times was much larger than at present, and from a consideration of the principles discussed in the present note it appears to represent the filling by water of a great senkungsfeld having the moun- tainous country on the western portion of the lake proper as one wall, the eastern wall of the lake for another, and the rugged and youthful Takitimu Range for another wall. The beginning of the fiords which break its western and northern walls may also have been in heavy cross faulting, but it is certain that the fiords have been intensely glaciated during the recent Ice Age, and that the long and profound canons discharging into the fiords may be easily explained by erosive processes alone. Similar reasoning may be extended to the case of Lake Wakatipu where faulting appears to have been most pro- nounced especially about Arrowtown, The Crown Terrace, and the great west front of The Remarkables. Heavy erosion by ice, however, is evidenced on the lower hills, the thickness of the ice stream having been several thousands 136 E. C. ANDREWS. of feet. It is probable that the Tertiary strata found in the valley have been let down by Late Tertiary faulting. Similarly for all the large Alpine lakes and most of the magnificent fiords of the west coast. In each case most intense ice action is evidenced, but there are also signs of _ formative activities other than those of streams. In some cases, for example, Dusky Sound, Doubtful Sound, Lake Manapouri and Lake Wanaka, it is highly probable that the basins have originated in heavy faulting action with the production thus of senkungsfelder, and that the senkungs- feld valleys have in later time been modified and extended headwards as canons, first by ordinary streams and then by ice action. The evidence for this conclusion is simply an application of the principles dealt with in this note and consists of the intimate association of topographical sur- faces in quite different stages of development in dense resistant geological complexes. Some of the lake and sound basins, such as those of Wanaka, Hawea, Wakatipu, Manapouri, Te Anau, Doubtful, Breaksea and Dusky Sounds are situated also where one could not expect them to be, if they had been the products of stream corrasion, and their maximum depths moreover, occur in places where the maximum stream scour could not have taken place. On the other hand the canons which open out into them are generally such as might have originated in stream action. It may be that certain large Alpine lake basins in other regions may be due also both to dislocations and to intense water and glacial action during a still later period. ON THE GEOLOGY OF WEST MORETON, QUEENSLAND. 137 NOTES on THE GHOLOGY oF WEST MORETON, QUEENSLAND. By R. A. WEARNE, B.A., and W. G. WOOLNOUGH, D.sc., F.G.S. [Read before the Royal Society of N. S. Wales, August 2, 1911. | I. Introduction.—The area designated in this paper as the West Moreton District extends from the Brisbane River on the north, to the McPherson Range on the south, and from the Logan River on the east to the Main Dividing Range on the west. Dr. H. I. Jensen, in his paper on the Alkaline Rocks of Southern Queensland, at the Brisbane Meeting of the Australasian Association for the Advancement of Science, referred to the Main Dividing Range as the Little Liver- pool Range. In the following remarks the title Little Liverpool Range is applied to the spur of the Main Range that runsfrom Mount Castle northwards, and is crossed by the Brisbane—Toowoomba Railway Line between Grand- chester and Laidley. II. Work of Previous Observers.—The northern border of the area under discussion has formed the subject of a monograph by Cameron.’ In this report the general sequence of the Ipswich Coal Measures is worked out, but no description is given of the volcanic series which forms the subject of the present paper. Jensen’ has studied the voleanic series. He describes a number of rock types, particularly from Mounts Flinders * Cameron, W. E.—Geology of the West Moreton or Ipswich Coalfield. Geol. Survey of Queensland, Rep. 1899. * Jensen, H. I.—Notes on the geology of the Mount Flinders and Fassifern Districts, Queensland, Proc. Linn. Soc. N.S.W., Vol. xxxIv, 1909, pp. 67-104; also The Alkaline Rocks of Southern Guepneleds Rep. Aust. Assoc. Adv. Science, Brisbane, 1909, pp. 249 — 258. 138 R. A. WEARNE AND W. G. WOOLNOUGH. and French. These he assigns to a variety of alkaline lavas. He is of opinion that “ the volcanic rocks of the Fassifern Scrub are all Post-Triassic and probably Post- Cretaceous.” He describes the area under consideration as a senkungsfeld and gives a detailed account of the tectonic geology. Marks’ is of opinion that the age of the volcanic series in the neighbourhood of Beaudesert is Trias-Jura, in which idea he follows Rands.’ In an account of Mount Lindsay in the Macpherson Range Andrews’ describes the eruptive trachytes as Trias-Jura in age. It will be seen then that considerable diversity of opinion exists in connection with this important question. III, Physiography.--The contour of the Main Dividing Range which separates West Moreton from the Darling Downs reveals the fact that two successive uplifts occurred, the first an uplift of about 2,000 feet, and the second of about 2,700 feet. The summits of the Main Range—Mounts Castle (3,700 feet), Cordeaux (4,100 feet), Mitchell (4,000 feet), Spicer (4,100 feet), Huntley (4,150 feet), Roberts (4,350 feet), and Wilson (4,060 feet) are practically at a uniform height above sea level. They represent the denuded remnants of an uplifted peneplain. The uniform level of this uplifted peneplain can be seen from the summit of Mounts Spicer and Mitchell gently sloping westwards across the Darling Downs. Four well defined “‘air gaps’’ occur between Spring Bluff and Bald Mountain, Mounts Cordeaux and Mitchell, Mounts 1 Marks, HE. S.—Coal Measures of South East Moreton, Queensland Geol. Survey, Publ. No. 225, p. 52, Brisbane 1910. 7 Rands, W. H.—Report on the Albert and Logan District, Qeensland, Parl. Papers. C.A. 5, p. 2, Brisbane, 1889. 3 Andrews, E. C.—A Preliminary Note on the Structure of Mount Lindsay. Rec. Geol. Surv. N.S.W., Vol, vir, 1903, pp. 328 - 240. ON THE GEOLOGY OF WEST MORETON, QUEENSLAND. 139 Mitchell and Spicer, and Mounts Roberts and Wilson. They represent the U-shaped mature river valleys eroded to base level, which have since been elevated to a height of about 2,700 feet above sea level. Cunningham’s and Spicer’s Gaps still preserve a perfect U-shaped contour, the latter being one and three quarter times the size of the former. A magnificent view of these ‘“‘gaps’’ can be obtained from the western side of “Jump Up,”’ a high ridge which runs to the north of Mount Alford about six anda half miles to the west of the township of Boonah. The gap between Spring Bluff and Bald Mountain has been faulted to a depth of about 500 feet below the uplifted peneplain, whereas Cunn- ingham’s, Spicer’s and Wilson’s Gaps are on the edge of the escarpment. These gaps have at the present time an important influence upon the meteorology of the eastern coastal plain. In Cainozoic times the Water Divide existed far to the east of its present position, and four important western flowing streams carved the U-shaped valleys of the afore- Said gaps to base level. The most northern of these rivers followed somewhat the course of the Lockyer and Murphy’s Creeks and flowed through the Spring Bluff gap near Toowoomba. Its tributaries on the left bank carved the agegraded U-shaped valleys through which Blenheim Creek and Laidley Creek now meander, and the rich agricultural lands of the famous Lockyer District are the result of their work. Thesecond river flowed west through Cunningham’s Gap, and one important tributary on the right bank is represented by the magnificent V-shaped gorge of Reynold’s Creek, which cleaves Mount Edwards. This gorge is at present about two miles long, its sides slope at an angle of 40°, and the summit of the V on the east is 1,000 feet above the bed of Reynold’s Creek, and that on the west 1,800 feet. It much resembles the famous Upper Shoalhaven River 140 R. A. WEARNE AND W. G. WOOLNOUGH. Gorge of New South Wales in appearance. The third stream ran roughly parallel to the second, divided from it by Mount Greville, and flowed through Spicer’s Gap. The fourth stream followed the upper valley of the Teviot, flowed through Wilson’s Gap, and thence along the upper course of the Condamine through the gorge known locally as ‘*Sydney Heads.”’ IV. Earth Movements.—In Cainozoic times the district was reduced to a peneplain level. It was next elevated to a height of about 2,000 feet, and the mature river valleys referred to above were worn to base level in the volcanic products. This is proved by the uniform depth of the U’s below the summit level. A second uplift of about 2,700 feet next occurred in late Cainozoic time, as proved by the fact that the uniform level of the ‘air gaps’ is at the same height above sea level. The comparative recency of the movement is indicated by the very slight alteration in form suffered by the uplifted valleys since their elevation. Hxtensive trough faulting then occurred between Indoo- roopilly near Brisbane and the Main Range. ‘The first faulting probably resulted in the production of what we call the Lockyer Fault Block, bounded on the west and south by the Main Dividing Range, and on the east by the escarpment of the Little Liverpool Range. This block is traversed by four meridional ridges :—the Little Liverpool Range, the Mount Mistake Range, the Hip Roof, and another of unknown name, with horizontal crest lines rising to a uniform level of about 2,000 feet. Immediately to the east of Toowoomba this faulting carried down a portion of the old mature valley about 500 feet below its original level. The faulting here was somewhat complex, and this fault is associated with one or more others increasing the total throw. ON THE GEOLOGY OF WEST MORETON, QUEENSLAND. 141 The second period of movement produced the Fassifern Block lying to the east of the Little Liverpool Range and the approximate collinear portion of the main range to the gouth of the junction. This fault probably amounted to about 900 feet. The throws of these faults have been calculated from the following evidence :— i. The mature topography of the main range near Too- woomba is continued to the east near Spring Bluff ata lower level of about 500 feet. ii. At the main range near Toowoomba basalt caps the coal measures at an altitude of 1,700 feet above sea level. It can be clearly seen from the railway line at the ninety- three mile post from Brisbane. Throughout the Lockyer Block a similar flow of basalt up to 600 feet in thickness caps the coal measures in each of the four ridges at a height of 1,200 feet above sea level. iii. At Mount Walker, a peak belonging to the Fassifern Block, basalt also caps the coal measures, but at a height of only 300 feet above sea level. This evidence is supported by the appearance of the sandstones and grits of the coal measures in the railway cuttings along the main range and the Little Liverpool Range. At the ninety-one mile post near Spring Bluff the slickensided surface of the fault scarp can be clearly detected. Between the first and second railway tunnels in the Little Liverpool Range a marked change in the dip can be noticed along the line of fault, and slickensided sur- faces were found in the grits and sandstones. One mile to the west of Ipswich the coal measures are tilted at an angle of 80°, and the Bremer River follows the line of fault for a distance of over two miles from Berry’s Lagoon to Coal Falls. 142 R. A. WEARNE AND W. G. WOOLNOUGH. V. Geology —(I) Sedimentary Rocks. (a) Permo-Carboniférous Rocks.—An inlier of Permo- Carboniferous rocks is to be found immediately to the north- west of Mount Barney, a high double peaked mountain, which is situated about six milessto the north-north-west of Mount Lindsay. These rocks have been previously con- sidered as of Trias-Jura age, but the discovery of a definite specimen of Fenestella fossula, Lonsd., submitted to Mr. W. 8S. Dun for identification places them in the Permo- Carboniferous. This is the first record of Permo-Carboni- ferous fossils in the West Moreton District. (b) Trias-Jura Rocks.—The representatives of the Trias- Jura rocks met with in the area under consideration are to be referred to the Welloon stage. They consist of con- glomerates, grits, sandstones, and shales with thin seams of coal. The coal measures form rather poor soil, and the surface ridges are mostly used for grazing purposes. (II) Eruptive Rocks. Four distinct periods of volcanic eruption can be traced in the West Moreton District by the occurrence of :— 1. Trachytes. 2. Andesites and Dacites. 3. Rhyolites. 4, Basalts. 1. TRACHYTES. Trachyte eruptions occurred along a zone running from the main range to Mount Cordeaux inan easterly direction to Redbank Plains, about eight miles south-east of Ipswich. These eruptions produced a number of cones, whose denuded remnants may now be seen at the summits of the main range and at Mounts Matheson, Greville, Edwards, French, Flinders, and the ridge to the south of Redbank Plains. The flow of this period attained a thickness of about 2,000 feet. ON THE GEOLOGY OF WEST MORETON, QUEENSLAND. 143 Mount Flinders.—The trachyte series at Mount Flinders (2240 feet) can be subdivided into three distinct sub-periods of eruption.. The first produced the dark basic looking trachyte (pantellarite of Jensen). It has a characteristic greasy looking lustre much like phonolite. The lower hills on the the northern side of Flinders are composed of this rock. The second sub-period produced the light alkaline felspar porphyry which composes Flinders and a number of the neighbouring peaks. Two distinct dykes of this light trachyte run from Flinders through the pantellarites, one to the north-west of that mountain, 20 feet wide, shewing well defined horizontal prismatic structure. The third sub-period produced a pitchstone porphyry containing phenocrysts of sanidine embedded in a black glassy matrix. (See petrographical descriptions.) Mount Blaine about two miles to the north of Mount Flinders is composed entirely of this material with inclu- sions of light and dark trachyte. One inclusion of the light variety measured 6° x 4’, and another of pantellerite 4”, Ivory’s Rock which can be seen about three miles to the east of the Rockton Railway Station, standing like a large obelisk above the plain, is about 1,300 feet high, and is composed entirely of trachyte breccia. At a point 400 feet from its summit the angular masses of breccia are cemented in a matrix of trachyte glass which seems to have forced its way from the centre of eruption through the porous masses of scoria. Main Dividing Range.—The main range near Cunning- ham’s Gap is composed of alkaline trachyte capped by olivine basalt. Mount Matheson (2,660 feet). appears to have been the main focus of the trachyte eruption of this district. Its summit consists of vesicular trachyte sur- rounded on all sides by huge masses of trachyte tufl, breccia ~ voy s = and conglomerate containing angular masses three feet in diameter. A steep escarpment exists to the north and west, and a ridge connects this mountain on the southern side with the lower slopes of Mount Mitchell. Johnston Greek and Clayton Gully rise in the elbow thus formed. A perfect view of the well defined U-shaped mature valley of Cunningham’s Gap can be seen from the summit of Mount Matheson. 144 R. A. WEARNE AND W. G. WOOLNOUGH.. ” Mount Mitchell (4,000 feet).—A splendid section of the volcanic series and the associated sedimentary rocks is revealed in Gap Oreek (the eastern one of this name) and the wonderful escarpment of Mount Mitchell itself. The Walloon stage of the Ipswich coal measures is distinctly intruded and capped by trachyte, and these in turn by basalts. A fairly thick seam of coal outcrops about one mile below the ‘Second Falls.’’ It is intruded by a dyke of basalt which has opened out into a sill along the seam. Several basalt dykes occur running roughly north and south at right angles to the creek, and each in turn causes the formation of a pretty waterfall. ; Cunningham’s Gap consists of a perfectly shaped U situated between Mounts Cordeaux and Mitchell, the trough being 1,500 feet below the summits of those mountains. It presents one of the finest examples of an Air Gap to be seen in any part of Australia. At the lowest point of the gap trachyte breccia is met with. The base of Mount Mitchell is composed of alkaline trachyte, tuff and breccia for a thickness of about 1,500 feet, and this in turn is capped by about 1,000 feet of basalt. The entire thickness is made up of a very considerable number of independent beds of volcanic material, each one practically horizontal. The summit of Mount Mitchell consists of a narrow ridge run- ning north and south. Viewed from the east it shows a broad rounded summit with a vertical escarpment of about ON THE GEOLOGY OF WEST MORETON, QUEENSLAND. 145 2,000 feet. From the south it appears as a huge inaccess- ible pinnacle. The narrowest part of the summit is not more than nine feet across, and a stone can be dropped on the eastern side for a depth of at least 1,500 feet before striking the rock face, while on the western side there is a similar cliff of about 500 feet. From the summit of the mountain an excellent view of the low lying Fassifern Block can be obtained, and beyond the hills around Ipswich, which bound the block on the east, the waters of Moreton Bay are visible. Mount Greville (2,700 feet) the sentinel of ‘‘ The Gap,”’ Situated about five miles to the east of the Main Range, is composed of grorudite, and its present contour is probably due to the erosion of the mature rivers that formerly flowed through Cunningham’s and Spicer’s Gaps. The northern slope corresponds in contour with the southern slope of the former, while the southern contour goonies the outlines of the northern slope of the latter. The eastern side of Mount Greville is cleft by fissures from 6 feet to 20 feet wide with precipitous walls from 100 feet to 200 feet in height. They have been formed by basalt dykes which being less resistant than the grorudite have been completely eroded. These clefts are studded with magnificent palms, ferns, and orchids, and form one of the most picturesque spots in Southern Queensland. Mount Edwards (2,300 feet) is composed of trachyte intruded by basalt, and Mount French (1,800 feet) is com- posed of comendite, tuffs and breccias. Spicer’s Peak (4,100 feet) presents a section almost identical with that of Mount Mitchell, and like the latter has a vertical escarpment on the east. 2. ANDESITES AND DACITES. A parasitic cone of andesite occurs along the old Warwick Road which runs through Spicer’s Gap (See Fig. 1). Here J—August 2, 1911. (auoo oniseied eyhyorry, “Oz | 99449819 [eprojepshury ‘eT e1Ayoery, ‘9 : Ajqeqoad) oytsapuy +77 IES Weseq ‘61 —eyhyorsy o1seq ‘ZT HU, ‘*G | eyXp seseg °9Z eqhyovry, “QT Hoy oykyoray, “T] Bo, ‘f ; ayAp yesegq ‘Gz eqAyoesy o1seq ‘/T| ayAyorsz o1seq ‘Q] ajAyoery, “¢ ayAp oyljouoyg ‘Fz e1000AQ, 07¥19 M10] 3 e10001q q[eseq oulalgQ ‘ez | pue gyno ojdyoery, ‘g] | -Se o1Ayoesy osavop ‘6 pue yn, oadyoury, ‘Z . synq oyAyqovly, ZZ eyfyoudy, ‘CT ayAyouly, °g eyizjaenb pue pny oykyoery, “[Z Buy, ‘PI Poy 2, | eucjspues eanp-seny *{ {204 O0ol “~—__.-_ AjedS jedijsa\s Spuejoavi— = _9e9G yPloZoH R. A. WEARNE AND W. G. WOOLNOUGH. CZ —-ALASA|IW = YOY $ AoUAaNDH $224 001 yeag Suadidc 146 ‘ooo youniwy PIO Suojn sbuvy wwpy fo woroaog—T{ ‘s1q ON THE GEOLOGY OF WEST MORETON, QUEENSLAND. 147 there is distinct evidence that the andesite intrudes and caps the trachyte. Mount Alford (2,200 feet) about three miles to the east of Mount Greville is composed of andesites, quartz-diabases and devitrified obsidians, etc., intruded by rhyolite dykes. This mountain presents a fine field for research work and ‘holds the key to the volcanic sequence. It is hoped that a detailed examination will be made later. Mount Maroon (3,300 feet) about 12 miles to the E.S.E. of Mount Alford is composed entirely of rhyolite. Two features are here worthy of note (1) the occurrence of huge vertical prisms 150 feet high on the northern side of the summit, and (2) the presence of two small but very deep elliptical lakes near Mr. Rose’s Farm on the mount side. These lakes are surrounded by rhyolite breccia and tuffs, and have never been known to be dry. The larger one is 150 yards long by 75 yards wide. Mount Barney the culminating peak of southern Queens- land, 4,625 feet high, is also composed of rhyolite, intruded by basalt dykes. It is situated between Mount Maroon and the McPherson Range. 3. RHYOLITES. A large rhyolite dyke intrudes trachyte at Johnston Creek, about one mile to the west of Mr. Anderson’s house ‘*Marraboola,’’ in portion 92 V, Parish of Clumber. Glennie’s Pulpit consists of the plug of rhyolite on the north-western side of Mount Alford. It stands about 120 feet above the contour of Mount Alford, and is composed of practically horizontal hexagonal prisms, pointing to a vertical conduit for the molten magma. It is surrounded by acid tuffis and breccias and represents a centre of rhyolite eruption. ee | ? ® ab 3 . » 148 R. A. WEARNE AND W. G. WOOLNOUGH. 4, BASALTS. Basalt intrudes and caps trachyte along the Main Divid- ing Range near “The Gap.’”’ Basalt dykes intrude trachyte at Mounts Greville, Edwards, French and Flinders. Basalt dykes intrude andesite at Mount Alford, and basalt dykes intrude rhyolite at Mount Barney. A striking difference is presented between the relation- ship of the basalt dykes to the streams near the Main Range and at Mount Barney. At the former locality the dykes cross the streams at right angles, whereas at Mount Barney the streams are subsequent and follow the course of the dykes. Basalt seems to have been extruded through- out the whole district by fissure flows. At the Main Range near Toowoomba two distinct dykes of large dimensions can be seen along the eastern escarp- ment—one at the 93 mile post on the railway line from Brisbane, 200 yards in thickness, and the other at the 91 mile post exposing a width of 600 yards in the railway cutting. Intrusive sills of basalt occur on the Main Range along the old Warwick Road at an altitude of 2,040 feet, and at the “Jump Up”’ see figs. 1 and 2. Fig. 2. | “>= Sandstone =am ‘ oa 262 W. R. HEBBLEWHITE. plates with varying apertures on the top of the float. For quantities above 1°4 cubic feet per minute, this plate is replaced by one having a hole sufficiently large to pass a large proportion of this amount ofair. The float now falls considerably, but further increase in the rate of flow will again cause it to rise and begin a new range. There are three such “‘ranges”’ of readings, giving a total capacity of 8 cubic feet per minute. The capacity might be increased by enlarging the discharge holes, but this would decrease the sensitiveness. For a larger plant, however, it would be advisable to do so. 4. Calibration. —Hach range was calibrated separately, and the curves are shown in Fig. 3. Calibration was effected by the use of standard meter calibrating tanks. The varying pressures of the air were read from a mano- meter, and the necessary allowance made. 5. Diagrams.—Sample diagrams taken by the instrument. are shown in Fig. 4, superimposed, with a common zero line. The amount ofair passing was varied by the air cock on the exhaust main. It will be observed that in the second and third ranges, the vibrations diminish very con- siderably as compared with the first range diagram. | 6. Impulse Absorber.—The absorber apparatus, as at first. arranged, was an attempt to provide a reservoir in the air passage, which, while free to take up, by change of volume, the irregularities in the air flow, maintained at the same time the constant pressure corresponding to that in the instrument for the given rate of flow. This was easily arranged by the use of a small gasometer in the air path, the float of which was balanced by a counter-weight sufficiently large to give the required air pressure. The gasometer rose and fell under the varying irregularities, but the air passed on at a constant pressure to the recorder’ and gave a good diagram. The gear was not automatic’ “gnoyf yp fo don oy) 07 pagzyf ‘hgaarjoadsas ‘saqnjd ainjisdy aban) puv ‘aingusdn yous ‘yunjg oy) burguasasdas sabuvs oasyg ay sof saaing buywsquog—e *Biq ‘OyNUIP, Jod yoo O1QnH UL MOTA-aATY JO Oger § 8G 9-6 PG GG 6 8-1 9-1 v1 Gl “Tl 8: 9. V: G- ie | i ‘SoqOUy Ul WeISseIq Jo JUSIOH “4osuapuo,) Uo poop unazs ou yp uayn suvsbory ajdungy pasodursadng—p “B1q et i ei TS ay RADAR GILLd Soa dal WVU cai ‘asuvy palyy, “WF ‘HOTJOV JO JNO UMOIYY YUeMINAYSUT “PY 4 ‘eSuey puooeg “7 ‘quejd Jo osvyvo] [VWION “7 “9S UT Joq1OSqe OU YYIM ‘osuVY 4SILY “G {NYS YOO aovyVol ILy “yy ‘19JVM 1OAO POX 19q10sqe YIM ‘gsuey 4SIlq ‘O ‘ATYYSIS posvotoop osvyvo] IIy ‘¢ _‘pegdope AT[eug se ‘surads suoy Aq 1098 ‘PpOSVOLOUL OSVYLO[ ITY JOAO popuedsns areqsosqe TAI ‘osuVYy ISI “T ‘OUIT 0107 °F ‘WOTJOW OFUL UMOIYY JUOUINAYSUT ‘esUVY 4SITT +9 INLET LONG EXTENSION SPRING Fig. 5—Impulse Absorber, for damping the impulses due to the action of the pump. and required adjustment of the counter-weight for varia- tions of the mean rate of flow, i.e., of the mean pressure. The apparatus finally adopted (Fig. 5) is a modification of the above and is automatic initsaction. A spring replaces the cord and counter-weight. Hence, the gasometer rises under the air pressure until the tension of the spring has relaxed sufficiently to give equilibrium. By choosing a spring of very long range, a considerable variation in volume may occur by rise or fall of the gasometer without any appreciable change in the mean pressure of the air. The efficiency of the apparatus is demonstrated by the sample cards. 266 W. R. HEBBLEWHITE. The author desires to acknowledge his indebtedness to Prof. S. H. Barraclough for his help in the construction of the apparatus, and to Messrs. Parkinson and W. and B. Cowan for the use of their calibrating plant. SOME NEW ENGLAND EUCALYPTS AND THEIR ECONOMICS. 267 ON SOME NEW ENGLAND HUCALYPTS AnD THEIR ECONOMICS. By RicHArD T. BAKER and HENRY G. SMITH, Technological Museum, Sydney. With Plate XIII. [Read before the Royal Society of N. S. Wales, November 1, 1911. ] Introduction.—The ground covered by this paper includes botanical remarks, descriptions, chemistry of the oils and general economics of the following species of Eucalyptus: . acaciaeformis, Deane and Maiden. . Andrewsi, J. H. Maiden. . Bridgesiana, R. T. Baker. . laevopinea, R. T. Baker. . nova-anglica, Deane and Maiden. mot by by fy fy . campanulata, sp. nov. New Hngland might be called the land of the ** Pepper- mints,’’ for in no other part of New South Wales is the term ‘“‘ peppermint ’’ applied to so many Hucalypts in such an indiscriminate manner, and one might add without sufficient reason, for many of the trees so called do not contain the peppermint constituent, piperitone, in their oil. What has been the ruling feature in such naming is, how- ever, not far to seek. The designation has most probably been applied originally, and since passed on, to the nature of the bark, for it resembles in its general features the characteristics of the Sydney Peppermint, EH. piperita, to which species of Hucalyptus the name peppermint, owing to the presence of the peppermint constituent, was applied by the medical officers of the First Fleet in 1788, and con- sequently this is regarded as the type of all peppermint barks. - ‘ It would have been better from a commercial standpoint if the early northern settlers had acquired more than a superficial knowledge of the trees from a general appear- ance of their barks, before applying a common name. 268 R. T. BAKER AND HENRY G. SMITH. Out of the four so called “‘peppermints’”’ only one,—H. Andrewsi, is really entitled to be called a ‘‘peppermint,”’ as neither of the three others contains piperitone in their oil, whilst the new species here described yields that constituent, and yet has not received the name of pepper- mint so far as we are aware. This is a good illustration of how chary one must be in dealing with Hucalypts from their common names. The following will give some idea of the vagaries of vernacular nomenclature in this district of four of the Species mentioned in this paper :— E. acaciaeformis. Red Peppermint at Tentertield, Peppermint (generally). Narrow-leaved Peppermint (Deane and Maiden). EL. Andrewst. Peppermint at Bundarra. New England Peppermint. E. Bridgesiana. White Peppermint at Uralla. White Peppermint at Tenterfield. White Peppermint at Woolbrook. EL. nova-anglica Black Peppermint at Black Mountain. Red Peppermint at Armidale. Red Peppermint at Woolbrook. Broad-suckered Peppermint (J. H. Maiden). Timber.—The timber tests here given have been made by Mr. Nangle, Lecturer in Architecture at the Technical College, and are the first recorded. SOME NEW ENGLAND EUCALYPTS AND THEIR ECONOMICS. 269 Oils.—The portion devoted to the determination of the volatile oils of the species of Hucalyptus included in this paper, embraces two sections: (1) The investigation of new oils obtainable from the leaves of H. Andrewsi, EH. acaciae- formis and E.campanulata; and (2) results of investigations into oils of species not examined previously from this locality. The results obtained by this additional chemical evidence go to support the fact that there exists a remark- able constancy in the chemical products of identical species of Eucalypts, which has enabled an auxiliary method of discrimination between species to be evolved, one which in conjunction with botanical and physiological features assists in determining the relations between members of the several groups and allied sections of this large class of Australian vegetation. The study, in this instance, has been devoted largely to the characters of the oils derived from species yielding products which may perhaps be considered of an anomalous nature, so far as ordinary Hucalyptus oils are concerned. The economic side of this question, too, cannot be ignored, especially in view of the prominence Kucalyptus oil has lately reached. The species dealt with in this section are H. laevopinea, E. nova-anglica and HE. Bridgesiana. Prior to the discovery of the promin- ence of the terpene pinene in certain Hucalyptus oils, it had been generally recognised that the terpene phellandrene was the most abundant product of their terpene oils. While this is true, so far as the species of one large group is con- cerned, yet, it has been possible to show that not only does the terpene pinene occur in abundance in the oils of some Hucalyptus species, but that both active modifications are obtainable from different trees. Hucalyptus laevopinea may, probably, often have been considered by botanists as EH. macrorhyneha, the ‘* Red Stringybark ’’ of Southern New South Wales, or perhaps E. pilularis, but from a com- mercial point of view alone this supposition cannot- be a 270 R. T. BAKER AND HENRY G. SMITH. entertained, and it was with the endeavour to determine how far the constant botanical and chemical characters hold that the present investigation has been undertaken. The localities, Armidale and Uralla, are far away from Rylstone from which locality the first described material was obtained. The original data derived from that material were published in our work ‘‘Research on the Eucalypts,”’ pp. 41 and 242. Hucalyptus species appear always to give chemical products practically identical in composition and general characters, no matter where found growing, of course allowing for slight differences always found in natural products of this nature. While one could readily distil laevo-rotatory turpentine from the leaves of Eucalyptus laevopinea, it would not be possible to do so from those of either HE. macrorhyncha or H. pilularis. Unfortunately the yield of oil from naturally growing trees of EH. laevopinea is somewhat small (0°6 per cent.), and thus the commercial production of turpentine from this source is not possible at its present price, (although the yield of oil from EH. dextro- pinea is somewhat larger) but it perhaps might be feasible, by a proper system of treatment and cultivation, to induce this and similar species to secrete a greater abundance of pinene, and so render its production profitable. If the quantity of oil from the chief pinene bearing species was as great as that from the most prolific phellandrene bearing species, the maufacture of turpentine from the Eucalypts could be made a profitable undertaking. From all the evidence we have obtained there seems no doubt but that E, laevopinea is a distinct species of Hucalyptus, and differs in characters from any other. It may, perhaps, be con- sidered as the “‘Stringybark”’ of the Northern Highlands of New South Wales, while E. macrorhyncha is the ‘*Red Stringybark’’ of Southern New South Wales, and as the one species goes north and the other comes south, they both meet in the neighbourhood of Rylstone, and are thus found growing together in that locality. SOME NEW ENGLAND EUCALYPTS AND THEIR ECONOMICS. 271 The other species of special interest is H. nova-anglica. As its name implies, its principal location is in the New England district. The previous determination of its essential oil was published in the “‘ Research on the Huca- lypts,’”’ p. 34, and it was there shown to consist principally of the sesquiterpene peculiar to Kucalyptus oils. Nearly three-fourths of the oil of this species consists of that con- stituent. The chief terpene in this oil was also shown to be dextro-rotatory pinene. It might reasonably be supposed that the presence of such a large amount of a high boiling constituent as the sesquiterpene would cause the oil to alter considerably at various times of the year, or when the trees were grown under variations of climate, or influenced by soil or local conditions, and to decide this point further investigations have been made with the oil of thisspecies. Here again, however, was found a remarkable constancy of constituents and physical properties in the oils from varying localities. Species. EUCALYPTUS ACACIAEFORMIS, Deane and Maiden. *“Red”’ or *‘ Narrow-leaved Peppermint.”’ Historical.—It was first brought before the scientific world by J. H. Maiden in a paper on “‘Some Hucalypts of the New England Tableland,’’ read before the A.A.A.S. in 1898, being Hucalypt No. 3, of that article. Messrs. Deane and Maiden described and figured it in the Proc. Linn. Soc. N.S. Wales, 1899, under its present Specific name. Remarks.—This is one of the most widely distributed of the “‘Peppermints’’ of New England, and so far has not been recorded outside that area. Its oil is now described for the first time. Essential Oil.—Leaves were obtained from Tenterfield and distilled 15/1/10. The material was collected as for 272 R. T. BAKER AND HENRY G. SMITH. commercial distillation, so that the yield is an average one. The crude oil was red in colour, very mobile, and had a rank, turpentine like odour. It consisted principally of dextro-rotatory pinene and the sesquiterpene of Hucalyptus oils. Phellandrene could not be detected, and eucalyptol was only present in very small quantity. The amount of ester was somewhat large for an oil of this class, and con- sisted almost entirely of geranyl-acetate. In its general characters the oil of this species has some resemblance to that of E. nova-anglica, although the abundance of dextro- rotatory pinene (with a very high rotation), the less yield of oil, the higher ester content, the lower specific gravity, and the small quantity of the sesquiterpene, all show it to differ from the oil of that species. The following results were obtained with the crude oil :— Yield of oil per cent. = 0°197 Specific gravity at 15° C. = 0°8864 Rotation ap oa ai to Refractive index at 20° ©. = 1°4713 Insoluble in 10 volumes 80 per cent. alontenl Kster by boiling, 3°216 gram oil required 0°056 gram KOH=.".S.N.. = 17:41. Hster in the cold, two hours contact, 2°59 gram required 0°042 gram KOH ..S.N. = 16°21. From this determination the ester is principally geranyl acetate and the cold saponification of the oil shows 5°7 per cent. of that ester to be present. Only 50 cc. of the oil could be spared for rectification, and only one or two drops came over below 154° O. (cor.) Between 154 — 157° 70 per cent. distilled; between 157 —183 16 per cent. came over, leaving 14 per cent. of high boiling constituents in the still. The specific gravity of the first fraction at 15° C. = 0°8644; of the second = 0°8772 and of the residue = 0°9833. The rotation of the first fraction SOME NEW ENGLAND EUCALYPTS AND THEIR ECONOMICS. 273 a = + 40°4 or specific rotation [a], = + 46°74°; of the second fraction dy = + 35°5. The refractive index at 21° O. of the first portion = 1°4661; of the second =1°4686. The residue gave S.N. 80°6 or 28°2 per cent. of ester, calculated as geranyl acetate. The acid of the ester was isolated and determined to be acetic. The saponified oil had a marked odour of geraniol, but it was too small in amount to enable the alcohol to be separated. All the evidence, however, goes to show that the ester of this oil is almost entirely geranyl acetate. . HuUCcCALYPTUS ANDREwsI, J. H. Maiden. ‘‘New Hngland Peppermint.” Historical.—According to Mr. Maiden the specimens collected by Mr. W. Christie in 1877 in connection with his paper on”“‘The Forest Vegetation of Central and Northern New England in connection with Geological Influences,” Proc. Roy. Soc. N.S.W., 1887, belong to this species. Messrs. Deane and Maiden describe it in the Proc. Linn. Soc. N.S.W., 1898, p. 794, under the name of H. Sieberiana var. Oxleyensis. It was however raised to specific rank in 1904 by Mr. J. H. Maiden, Proc. Linn. Soc. N.S.W., and is more fully dealt with by this author in his ‘* Critical Revision of the Genus Hucalyptus,’”’ Part VII. (Vide note under remarks in this paper as to systematic position of this Eucalypt). Remarks.—Like most other Eucalypts this tree unfortu- nately has several vernacular names, being known as ‘Blackbutt,’ “‘Peppermint,’’ and ‘‘Messmate,”’’ but these are not mentioned here to be perpetuated, but the reverse, and the hope is expressed that the name of New England “‘Peppermint”’ will in future be associated with it. This common name now carries an important commercial significance from its association with phellandrene in the R—Nov .1, 1911. 274 R. T. BAKER AND HENRY G. SMITH. oil. The chemical results here given will probably lead to an exploitation of the tree almost immediately, as similar oils are now in great demand in connection with the treat- ment of ores by the flotation process. The botanical and chemical evidence available in the Technological Museum goes to show that this tree is the northern form of E. dives, Schau., and the fruits depicted in the “‘Critical Revision of the Hucalypts,’”’ Part VII, pl. 36, and ‘“‘Forest Flora of N.S.W.,’’ J. H. Maiden, Part XXI, under EH. Andrewsi, J.H.M., faithfully delineate those of BR. dives, Sch., (‘Critical Rev. Gen. Euc.”’ Part VII). The normal leaves of these two trees are identical, as also are the timbers and bark. It seems now that the only differ- ence so far is that no sessile, cordate, sucker (abnormal) leaves have been found in connection with H. Andrewsi as obtains in EH. dives. Mr. Cambage informs us that the seedlings of these two trees are different. The oil obtained from the Tenterfield specimens contains practically the same constituents as H. dives, although it is less in yield. These slight differences may perhaps be accounted for by its occurrence on granite ranges from which formation our specimens were obtained. Timber Tests.— TRANSVERSE TESTS. No. 1 | No. 2. No. 3. No. 4. Size of specimen | B.3; D.3;| B.3:04; D.3; |B. 3; D.2 99; |B. 299; D. 3-03; in inches L. 36. L. 36. issaG: L. 36. «Area of cross sec- 9 9:12 8:97 9°05 tion, sq. inches Breaking load in 4,960 4.990 4,660 5'900 tbs. per sq. in. Modulus of rupture 9,920 | 9,849 9°382 11,606 in Ibs. per sq. in. Modulus of elas- | 1,440,000 | 1,578,947 1,322,269 1,428,571 ticity in Ibs. per sq. inch Rate of load in ths. 708 623°7 €65°7 453°8 per minute SOME NEW ENGLAND EUCALYPTS AND THEIR ECONOMICS. OT Hssential Oil.—Leaves were obtained from Tenterfield and distilled 21/1/10. The material was collected as would be done for commercial distillation. The crude oil was lemon-yellow in tint, and but slightly coloured, and had a secondary odour of peppermint. It has all the appearances and characters of a “‘ Peppermint Oil,’’ and resembles very closely the oils distilled from the group of which H. dives may perhaps be considered the type. The principal con- stituents in the oilare laevo-rotatory phellandrene, piperi- tone, and the sesquiterpene, of which the first predominates | very greatly, in fact, this species may be considered as yielding one of the most pronounced phellandrene bearing Hucalyptus oils, not even excepting EH. radiata. Pinene appears to be quite absent, and eucalyptol was only detected with difficulty. The amount of ester was very small, as was to be expected. The crude oil gave the following Tests :— Yield of oil per cent. ... oe come ie Specific gravity at 15° C. ay ===) OF8646 Rotation dp oe ce bis ne AIS Refractive index at 15° C. We iy =e, 4B o4 S.N. of the ester + free acid ... soa Sa avd Insoluble in 10 volumes 80 per cent. alcohol. On rectification only a few drops of acid water and a small quantity of volatile aldehydes came over below 174 C. Between 174-178° 56 per cent. distilled; between 178 — 182° 26 per cent.; between 182—194° 6 per cent. The temperature then rose to 245° and between that and 255° 8 per cent. came over. It thus divided roughly into the fractions containing the main constituents, although in the higher ones phellandrene was still present. The specific gravity at 15° C. of the first fraction =0°8508; of the second = 0°8563; of the third = 0°8749; and of the fourth =0°9034. The rotation of the first fraction ay — 47°2; 276 R. T. BAKER AND HENRY G. SMITH. of the second —44°; of the third —32°9°; with the fourth light did not pass. The refractive index at 18° O. of the first fraction = 1°4819; of the second = 1°4839; of the third = 1°4862; of the fourth = 1°4968. The nitrite was prepared with the phellandrene, and was separated into two forms, one melting at 112—113° O. and the other melting at 105° OC. In view of the prominence recently acquired by the phellandrene Eucalyptus oils in the separation of metallic sulphides from ores by the flotation process, this species, as stated above, has value as an oil producing tree. The yield, however, is much lower than with such species as KH. dives or E. amygdalina. At present we do not know of any other species growing in the New England District of New South Wales from which a greater yield of phellan- drene oil can be obtained. EUCALYPTUS BRIDGESIANA, R. T. B. ** White Peppermint.”’ - Historical.—This was specifically described in the Pro- ceedings of the Linn. Soc., N.S.W., in 1898 by one of us. Remarks.—Since this species was established further material has been obtained from many parts of New South Wales, and its range even extended to South Australia. All this additional evidence goes to prove the stability of the species and further justifies the contention that it is quite distinct from the “‘Apple’’ of Victoria upon which H. Stuartiana was founded by Baron von Mueller, as main- tained by Dr. Howitt and J.G. Luehmann. Vide also remarks under EH. Bridgesiana, ‘* Hucalypts and their Hssential Oils,’’ p. 86. The fruits preserve a constancy of shape, but vary in size, the largest fruited form being at Woolbrook (Tam- worth). SOME NEW ENGLAND EUCALYPTS AND THEIR ECONOMICS. ye Essential Oil.—Leaves were kindly sent to the Techno- logical Museum from Walcha by Mr. J. F. Campbell, and distilled 18/9/99. The material was collected as would be done for commercial distillation. The crude oil was of an orange-lemon colour, and had an odour indicating an oil of the pinene-eucalyptol class. It was very rich in eucalyptol, contained some pinene, but phellandrene was quite absent. The higher boiling portion consisted largely of the sesqui- terpene common to these oils. The ester was small in amount. ‘The rectified oil was slightly tinged yellow as is common with the rich eucalyptol oils of this class. Leaves of this species were received later from Woolbrook and distilled 8/4/08. The oil was identical with that from the previous material both in the crude and rectified condition. The following are the results obtained with the crude oils from these two localities :— Walcha, 18/9/99. Woolbrook, 8/4/08. Yield of oil per cent. ... bet = O8F29 = 0°744 Specific gravity at 15°C. .... = 0°9223 = 0°9246 Rotation ap... ie ws +19 + 1°38 Refractive index at 19° OC. .... = 1°4716 at 20°= 1°4729 $.N. of ester and free acid ... = 8°7 0 Kucalyptol in portion distilling below 183° C. ie ...=73 percent. =78 percent. As the eucalyptol in the Walcha sample had been deter- . mined by the phosphoric acid method, that in the Woolbrook oil was also so determined. Rectifying the Walcha sample, between 172—183° 77 per cent. distilled; between 183 — 245° 11 per cent.; and between 245—265° 5 per cent. These results agree very well with those obtained with the Woolbrook sample. The first fraction as shown above consisted very largely of eucalyptol with pinene. The oil from the original Be id 4 278 R. T. BAKER AND HENRY G. SMITH. material described in the ‘Research on the Eucalypts,’’ p. 87, contained a little more dextro-rotatory pinene, owing to its being collected at the time of the year when pinene is most pronounced in the oils of this class, otherwise the oils are almost identical. A portion of the crude oil was rectified by steam distil- lation, as for commercial purposes. The product was yellowish in tint, resembling in this respect oils rich in eucalyptol of this class, as those of H. globulus, EH. gonio- calyx, etc. It had a good odour and consisted very largely of eucalyptol. It had specific gravity at 15° C. = 0°9203; rotation ap = + 3°1°; and refractive index at 21° C.=1°4602. KUCALYPTUS LAEVOPINEA, R. T. B. ‘‘Silver Top Stringybark.”’ Historical.—The first material (imperfect) of this species was obtained from the Gulf Road near Rylstone (R. T. | Baker), and was thought then to be a form of H. obliqua, L. Her., Proc. Linn. Soc., N.S.W., 1896. In the same Proceedings and later in the same year, Messrs. Deane and Maiden state, “they are unable to place it either with HE. macrorhyncha, F.v.M., or HE. capi- tellata, Sm. In “ Notes on a trip to Mount Sea View” by J. H. Maiden, Proc. Linn. Soc., N.S.W., 1898, appears the follow- ing reference to this tree:— | “HH, macrorhyncha, F.v.M. Near the summit of Mount Sea. View there occurs a Stringybark with large fruits undoubtedly belonging to this species. The fruits are similar to those collected by Mr. R. T. Baker, Gulf Road, Rylstone, except that the rim is a little more domed and the valves a little more exserted, probably because the Sea View specimens are a little riper. In my opinion Mr. Baker’s specimens are now undoubtedly to be referred to £. _macrorhyncha, F.v.M., a point in regard to which Mr. Deane and myself had some doubt.” SOME NEW ENGLAND EUCALYPTS AND THEIR ECONOMICS. 279 In 1898 full material was obtained by one of us, when the evidence derived from its investigation proved that it had characters sufficient to warrant its being raised to specific rank under the name of EH. laevopinea, Proc. Linn, Soc., N.S.W., p. 414. Messrs. Deane and Maiden in the same year and in the same proceedings refer to the species as follows:— “We have not had sufficient opportunity of examining these trees although we have been favoured with herbarium specimens by Mr. Baker . . . . we think it is a pity that the chemical pro- ducts of that species £. pilularis had not been enquired into before naming the two new ones.” (HL. pilularis had been chemically investigated at this time although not published.) “We must, however, offer our protest against. naming specics after recondite properties which can only be recognised after close analysis in the laboratory.” We are glad to see however, in the “Critical Revision of the Genus Hucalyptus,”’ Part VIII, p. 247, that Mr. Maiden now recognises the value of chemical evidence in determin- ing differences in species. Reference is again made to this species, Proc. Linn. Soc., N.S.W., 1901 by Deane and Maiden, in these words :— “We find that &. laevopinea, R. T. B., is specifically identical with £. dextropinea, R.T. B., and consequently with £. Mulleriana, Howitt.” In Part I of the ‘‘Oritical Revision of the Genus Huca- lyptus,’’ Maiden, places it along with E. dextropinea and E. Muelleriana as a synonym of H. pilularis,Sm. A deter- mination to which we cannot agree as our researches show that the two, H. pilularis and E. laevopinea, differ in timber, bark, fruits, buds. leaves, oil and habitat. In Part VIII, same work, E. Muelleriana is restored to specific rank; and on p. 221, the following reference is made :— 280 R. T. BAKER AND HENRY G. SMITH. “The fruits of E£. laevopinea, R. T. Baker, from Gulf Road, Rylstone (R. T. Baker) display such variation in size and shape as to have caused differences of views as to the species. For example, in Proc, Linn. Soc., N.S.W., 1896, Mr. Deane and I referred some of them to an abnormal form of £. macrorhyncha between it and Z£. capitellata. That they are identical with Z£. Mulleriana, Howitt, has since been shown ” Under EH. macrorhyncha in the same work no reference is made to E. laevopinea. Remarks.—¥rom the above it will be seen that on morphological grounds considerable differences of opinion have arisen in regard to this species. Since it was described in 1898, however, further material of this Kucalyptus has been examined from trees growing far north of the original locality of Rylstone, and so far no new facts have been brought to light that would warrant its being described as other than that it is specifically distinct from any of its congeners. ‘To place it under H. pilularis or EH. macro- rhyncha, with their chemical characteristics, would be fatal to the commercial exploitation of EH. laevopinea and E, dextropinea for their respective turpentine oils. With the price of turpentine now ruling, manufacturers will necessarily look to other fields for supplies. The “ Oil and Colour Trades Journal,’’ August 26th, says:—‘Accord- ing to Bulletin 40 of the United States Agricultural Depart- ment, the supply of turpentine in the United States will be exhausted in 1918. While the sources of supply have been decreasing, Statistics show the demand has increased over 90 per cent. in the last 15 years.’ This question is therefore of some importance to Aus- tralia, as it would be possible to procure early supplies of turpentine from young plants of pinene yielding Hucalypts grown from seed. The leaves of the young growth of eucalyptus species yield oils identical in composition with SOME NEW ENGLAND EUCALYPTS AND THEIR ECONOMICS. 281 that obtained from the mature trees, and often produce it in larger quantity. Byscientific treatment, beet has been made to secrete sufficient sugar to enable it satisfactorily to compete with sugar obtained from cane. Similar scien- tific treatment, with the right species, should also make it possible to produce turpentine from the EKucalypts to satisfactorily replace that now derived from the oleoresin of Pine Trees. Timber Tests.— TRANSVERSE TESTS. : No. 2. : No.1 | No. 3. No: 4. B. 3:00; | B.3:00, | B.3:02; | B. 302; Size of specimen in inches | D. 3:04; | D. 3°03; | D. 3:02; D. 3-02; L. 36. L. 36. L. 36. | L. 36. Area of cross section, sq. in. 9°10 9 09 9°12 9:12 Breaking load in tbs. per 5,750 5°750 5,050 5°710 square inch. | Modulus of rupture in ibs. 11,201 93138 9,901 11,196 per square inch. Modulus of elasticity in fbs.| 1,883,640 | 1,309,099 | 1,230,379 | 1,285,714 per square inch. Rate of load in ibs. per 638 650 505 | 713 minnte. | | Hssential Oil.—Leaves were obtained from Armidale, ist July, 1907, and from Uralla, 13th July, 1907. The material for distillation was collected as would be done for commercial purposes, so that the yield of oil given here is what would be obtained in practice. The crude oils in both instances were red in colour, but this colour being due to iron - derived from thestiJl, was easily removed with a few drops of aqueous alkali, or by agitating with two or three drops of phosphoric acid. The oil thus treated, after well wash- ing and drying was ofa very light lemon colour. When rectified, the products were colourless. The crude oil has a turpentine odour which is more pronounced in the large fraction distilling near the temperature required for pinene. Phellandrene does not seem to be present in the oil of this species at any time, thus differing in this respect from the 282 R. T BAKER AND HENRY G. SMITH. oil of EH. macrorhyncha. The stearoptene of Hucalyptus oils (Hudesmol) although such a pronounced constituent in the oil of HE. macrorhyncha, has not been detected in the oil of E. laevopinea. A very small quantity of eucalyptol occurs in the oil of H. laevopinea, not exceeding 5 per cent.- it is however a very pronounced constituent in the oil of KH. macrorhyncha. About 3 per cent. of ester, calculated as geranyl-acetate, is present in the oil of H. laevopinea. The following table gives the general results obtained with the crude oils of this species, those previously recorded for the Rylstone sample being given for comparison :— Rylstone. Armidale. Uralla. 1/8/98. 1/7/07. 13/7/07, Yield of oil, per cent. = 0°66 = 0:586 = 0:iihe Specific gravity, 15°C. = 0°8755 = 0°8875 = 0°8871 Rotation a, crude oil = B07 =o Rotation ap portion distilling below lo4- of the several fractions were—first + 30°3°; second + 22°4°; third — 2°1°. The light passed with the third fraction fairly well when diluted with an equal portion of chloroform. The specific gravity of the first fraction at 15° C. = 0°8652; of the second = 0°8713; and of the third = 0°9326. The refractive index of the first fraction at 19° OC. = 1°4679; of the second = 1°4724; and of the third = 1°4989. The first and second fractions were mixed and again distilled, when 9 per cent., calculated on the original oil, came over between 156-157° C. This fraction had specific gravity at 15° C. = 0°8631; rotation ay + 31°6, or specific rotation |a]p = + 36°61°; refractive index at 18°C. = 1°4677, and was almost pure pinene. With the Uralla oil 10 per cent. distilled between 160 — 170° C., which had specific gravity at 15° C. = 0°8638; and rotation ad) = + 27°7, and refractive index 1°4678. With the Armidale sample 10 per cent. distilled between -160-—170° C., which had specific gravity at 15° C. =0°8705; 7" 288 R. T. BAKER AND HENRY G. SMITH. rotation dp + 24°4°, and refractive index 1°4667. It con- sisted almost entirely of pinene, but eucalyptol was more pronounced in this oil, evidently due to the time of year when the material was collected. This is evidently the best species of Hucalyptus from which to obtain the sesqui- terpene to enable its chemistry to be determined. Kino.—The kino or astringent exudations of both the Armidale and Uralla trees were collected from the logs. Both gave identical reactions. It is friable, gives a green coloration with ferric chloride, and contains eudesmin, characters quite distinct from the kinos of the true ‘** Peppermints.” EXUCALYPTUS CAMPANULATA, Sp. nov. * Bastard Stringybark.’’ An average forest tree. Bark decidedly stringy, per- sistent on the main trunk, branches smooth. ‘* Sucker ’’ or abnormal leaves broadly lanceolate, oblique not shining, same colour on both sides, often over 9 inches long, venation well marked, lateral veins oblique, distant intramarginal vein well removed from the edge. Petiole over 1 inch long. Normal leaves comparatively small, lanceolate, oblique, subcoriaceous, not shining. Venation not at all well marked on the smaller upper leaves, but distinctly so in the others. Lateral veins very oblique. Buds, clevate or club shaped, the operculum domed. Fruits: At the earliest stage of development campanulate: on a Slender pedicel, a feature not noticed in other species by us. Mature fruits pyriform, rim truncate or slightly countersunk, about 6 mm. diameter at the rim. Bark “‘ stringy’ as implied in its common name. Timber, light coloured or whitish, fissile, but close q grained, easy working, in fact, similar in general charac- SOME NEW ENGLAND EUCALYPTS AND THEIR ECONOMICS. 289 teristics to some of the “Ashes” or ‘‘Stringybarks,”’ although perphaps a little more inclined to develop gum veins. [Arbor (Bastard Stringybark), distincta, nomine altitu- dinem 60 ft.,attinens, ramulis primum compresso-tetragonis mox teretiusculis. Cortex partim secedensin trunco persistens ramis levibus. Folia abnorme (suckers) obliqua falcato-lanceolata petio- lata, alterna concoloria vena peripherica a margine remota; vena laterale obliqua graviter. Folia vulgare, falcato- Janceolata, obliqua, petiolata concoloria, alterna subcori- acea, vena aut prominentes aut obscura obliqua, pleraque 3-6" longer. Pedunculi axillare umbellis multifloris; operculo-depresso hemispherica, mucronulatato breviter, calcycis tubus circa 1 cm. longus; fructibus truncato-ovatis, 1 cm longi, 5 mm. lati valvis non exsertis. | Remarks.—The material of this tree for investigation was collected by Mr. C. F. Laseron, the Museum Collector, at Tenterfield, where it passes as the “’ Bastard Stringy- bark.’’ His herbarium material appears to be identical with specimens collected by Mr. A. Rudder in the Upper Williams district. The fruits somewhat resemble those of EH. virgata, Sieb. or H. Sieberiana, but then the timber, bark and oil differ from these species. The oil of H. virgata consists almost entirely of eudesmol, as shown in our work on “The Kucalypts and their Hssential Oils.’’ Fruits, timber and oil differentiate it from EH. obliqua, which species has been collected in almost the same neighbourhood, at Mount McKenzie, Tenterfield. There isa distinguishing feature of the species in its very early fruits, which are quite bell shaped and remind S—Nov. 1, 1911 | Ve f : >) ° = one of the shape of the mature fruits of H. Deanei. As they mature, this shape passes gradually away, the calyx gradu- ally tapering into a pedicel, very rarely is the fruit hemi- spherical. 290 R. T. BAKER AND HENRY G. SMITH. On a cortical classification it would be placed with the ‘‘ Stringybarks,”’ or between them and the “‘ Peppermints,”’ but the timber may be classed as one of the ‘“‘ Ashes,’’ such as E. regnans, H. oreades or EH. Delegatensis. The large oblique suckers are not at all unlike those of H. obliqua, or even the above three species. At Tenterfield it is found growing amongst such ‘““ Stringybarks’”’ as H. obliqua and H. laevopinea. Hssential Oil.—Leaves of this species were obtained from Tenterfield, and distilled 14/1/10. The material was col- lected as for commercial distillation, so that the yield is an average one. The crude oil was of a light yellowish tint, and had a secondary odour of peppermint, due to a small quantity of piperitone. The presence of this con- stituent, and the absence of aromadendral, distinguish this oil from that of E. obliqua. A small amount of eudesmol was present at the time of distillation. The oil of this species consists principally of phellandrene, and pinene seems to be quite absent. EHucalyptol was detected in the portion distilling at about 176° C., but it was very small in amount. The oil of this species agrees with those of the members of the *‘Mountain Ash’’ group of Eucalyptus, but in its general characters more closely approaches, perhaps, that of E. oreades than any of the others. The following results were obtained with the crude oil :— Yield of oil per cent. ... “ag 5 | = Oa Specific gravity at 15° C. sa .. = 0°8804 Rotation ap ae oe i = 2iaee Refractive index at 18° e si .» |, = 14856 Scarcely soluble in 10 volumes 80 per cent. alcohol. Saponification number for ester + free acid = 7°6. | ; SOME NEW ENGLAND EUCALYPTS AND THEIR ECONOMICS. 291 On rectifying the oil only the usual few drops of acid water came over below 175° C., together witha very little oil containing some volatile aldehydes. Between 175 — 188° C. 68 per cent. distilled; between 188-224’, 11 per cent. came over; between 224 — 265°, 11 per cent. distilled- The specific gravity at 15° C. of the first fraction =0°8589; of the second = 0°8714; of the third = 0°9224. The rotation of the first fraction ap = — 34°8°; of the second — 32°6. Light did not pass with the third. The refrac- tive index at 18° of the first fraction = 1°4812; of the second = 1°4835; of the third = 1°4989. Kino,—The kino of this tree agrees in its appearance and reactions with those of EH. Sieberiana and allied species. It gives a violet coloration with ferric chloride, slowly changing toa grey precipitate, and does not contain either eudesmin or aromadendrin. — EXPLANATION OF PLATE. . Sucker or abnormal leaf. . Twig with buds and flowers and normal leaves. . Twig with leaf and fruits. i 2 » o Harly fruits. 4 5, Individual fruit. All natural size. vi ’ I ; - “oF a 292 J. A. THOMSON. ON ROCK SPECIMENS FROM CENTRAL AND WESTERN AUSTRALIA. COLLECTED BY THE ELDER SCIENTIFIC WXPLORING EXPEDITION OF 1891-2. By J. ALLAN THOMSON, B.A., D.Sc., F.G.S. (Communicated by Prof. David, B A., C.M.G., F.R.S., Hon. D.Sc, Oxon.) [With Plate XIV.] [Read before the Royal Society of N. 8. Wales, November 1, 1911.] THE rocks described in the present paper were presented to Professor David by Mr. Richard Helms, the naturalist of the Hider Scientific Exploring Expedition of 1891-2. Through the kindness of the former gentleman the writer was permitted to examine the collection and prepare the following notes on the rocks. The expedition, well equiped by Sir Thomas Elder, crossed from South Australia to the Murchison Goldfield in the years 1891 and 1892." A large number of rock specimens were collected all along the route, and a brief account of these, and of the chief geological features of the country passed over has been given by Mr. Victor Streich.? The . rocks here described appear to be in some respects supple- mentary to those listed by Mr. Streich. One of them comes from Fraser’s Range, H.N.H. of Norseman, W.A., 1 Cf. Lindsay, D., Journal of the Elder Scientific Exploring Expedition, 1891-2. With Maps. Adelaide, 1893. 2 Trans. Roy. Soc., South Austr., Vol. xvi, Part 1, 1893, pp. 74—110;. also Stelzner, A. W., Supplementary Notes on the above named Collection ibid., pp. 110-2. Tate, R., Appendix, List of Rock-specimens collected by Mr. Wells, Second Officer, on a Journey east from Murchison Goldfield, ibid., pp. 118-5. Map of route showing position of camps and geological formations, ibid., facing p. 236. ROCK SPECIMENS FROM CENTRAL AND WESTERN AUSTRALIA. 293 the other sixteen come from localities between the Barrow Ranges and the Hverard Range, t.e. between longitudes 127° HK. and 132° E., and latitudes 25° S. and 28° S. Considerable practical interest attaches to the geology of this region. In the first place it lies not far north of the country to be traversed by the proposed Transconti- nental Railway from Port Augusta to Kalgoorlie or Hsper- ance; and in the second, it lies to the east of the great belt of gneiss that forms the eastward boundary of the gold- fields of Western Australia, and there is still the possibility that new gold-fields will be found once the gneiss is crossed. The rocks, however, are not of a nature to give us as much information on the solid geology as might have been hoped, since they appear to be in large measure dyke rocks; on the other hand, some of them possess great intrinsic interest. | The gneissose belt referred to has been recently traversed and described by Mr. C. G. Gibson, for the Geological Survey of Western Australia.’ His map shows a large granitic or gneissic belt lying east of the greenstone belt in which Kanowna, Bulong and Mount Monger lie. The belt trends to the north-east and is succeeded on the east by the Tertiary limestones of the Hampton Tableland. Lindsay’s route in this part lay entirely within the gneiss, and this accounts for the paucity of fundamental rocks collected, for the gneiss area is largely covered by sand and spinifex flats. Streich considered this part of the country as “the most westerly part of the Great Australian meso- zoic basin.’’ The outcrops which he considered mesozoic, viz., “a System of terraces, having a general N.W. and 8.EH. trend, their strata dipping ata low angle to the North- * The Geological Features of the Country lying along the Route of the Proposed Transcontinental Railway in Western Australia, Bull. 37, Geol, Surv. W.A., 1909. 294 J. A. THOMSON. Hast ’’ are probably superficial deposits of desert origin similar to the surface quartzites of the South African arid regions. Dr. J. M. Maclaren has informed me that he has found such terraces northwards from Leonora, and that he considers them of analogous origin to the ferruginous laterites of Western Australia, and proposes to designate them by the name of “‘siliceous laterites.”’ The only rock in the collection from the southern end of this gneiss belt is that from Fraser’s Range. It is practi- cally identical with a rock collected by Gibson from Simon’s Hill, Fraser’s Range, and labelled ‘‘gneiss”’ in the Register of the Geological Survey of Western Australia (No. 8696). Besides garnetiferous gneiss, garnetiferous mica schist and pegmatite from Fraser’s Range. Streich records a horn- blendic schist as forming the main mass of the range, of which rock Stelzner writes:—‘'671 is according to the microscopic examination of the rock section, an undecom- posed diabase, which is distinguished on account of its containing highly pleochroic augite and biotite and apatite as accessory components.’’ ‘This is obviously the rock now to be described. The hand specimen is a dark, distinctly banded rock, the banding being due to the separation of the felspathic and the femic minerals into poorly defined layers. Microscopic examination shows that the latter minerals consist pre- ponderatingly of hypersthene, with subordinate biotite and rare hornblende. Iron ores and apatite are the only accessories (Fig. 1, Plate XIV). The felspars are some- times twinned on the albite and pericline laws, but the twinning is fine and not very constant, and is absent in many of the crystals. They all possess refractive indices superior to that of Canada Balsam, so may be all referred to plagioclase. The largest extinctions on symmetrically placed albite lamellae amount to 19’, indicating a species at least as basic as andesine. The felspars never show ROCK SPECIMENS FROM CENTRAL AND WESTERN AUSTRALIA. 295 crystal outlines, but form a polygonal mosaic of uneven grain. No evidence of cataclastic structure is seen, but strain shadows are not rare. The hypersthene is a little schillerised, strongly pleochroic variety with rose-red to green tones, and is optically negative with a fairly high optic axial angle. It occurs in irregular layers which have a rude parallel arrangement, but within the layer the mineral is not definitely oriented. It has sometimes con- siderable tendency to idiomorphism, but when surrounded by felspars occurs in more rounded forms. Closely associ- ated with, and often penetrating, the hypersthene is a considerable amount of reddish-yellow to black biotite. In Helm’s specimen, but not in Gibson’s, there is a little common green hornblende intergrown with the hypersthene. Apatite is fairly abundant in stout prisms with a general elongation in the direction of the banding. Fig.1, Plate XIV, gives an adequate idea of the relative proportions of the different minerals. While it is not impossible that the rock belongs to the gneissic series, its structure and mineralogical composition suggest, aS more probable, that it is of directly igneous origin, as Stelzner supposed, and is a norite with feeble protoclastic structure and well marked fluxion banding. The presence of hypersthenic dyke rocks at Norseman’ makes the presence of norite dykes in the Fraser Range quite probable. The northward extension of this gneiss belt has not yet been delimited by the Western Australian Geological Survey. Apparently the western margin turns north towards Burtville, where the gneiss is found a few miles east of the town.” The eastern boundary is unknown in the northern part. ' Campbell, W. D., The Geology and Mineral Resources of the Norse- man District, Dundas Goldfields, Bull. 21, Geol. Surv. W.A., 1906, p. 24. 2 Gibson, C. G., The Laverton, Burtville and Erlistown Auriferous Belt, Mount Margaret Goldfield, Bull. 24, Geol. Surv. W.A., 1906, pp. 29, 30. 296 J. A. THOMSON. Two rocks in the Helms’ collection are possibly to be referred here. The first is labelled ‘‘12 miles N.W. of Camp 23, 17/7/91,” i.e., in the northern part of the Blyth Range. It has the appearance and mineralogical composition of a hornblende granite, but some peculiarities in structure, though neither hand specimen or section show any parallel structure. Both orthoclase and quartz are abundant, together comprising the bulk of the rock, and the first peculiarity is the relation of these two minerals. Large pseudoporphyritic plates of orthoclase are found enclosing small rounded grains of quartz in poecilitic fashion (Fig. 2, Plate XIV). Such a structure, if original, as there seems no reason to doubt it is, may be explained by the fact that the magma originally contained quartz in excess of that required for the quartz-felspar eutectic. The structure is, however, further complicated by the presence of a thin zone of quartz-felspar intergrowth between the host and the enclosed mineral. Outside the large plates of ortho- clase such intergrowths are very abundant, but are always of fine grain, and have a great tendency to resemble grid- irons rather than the script-like forms that have given rise to the term ‘graphic.’ Their presence between the ortho- clase and enclosed quartz suggests that they are not original, but of the nature of “myrmekite,’ a type of struc- ture which in Sweden and Finland is taken to prove great metamorphism and the Archean age of the granite.” Besides orthoclase there is also a smaller amount of microcline and oligoclase, both bounded by similar intergrowths. The oligoclase is sometimes included within the orthoclase. All these minerals occasionally show strain shadows. The ' Cf., quartz in oligoclase. Dwerryhouse, A. R., On some Intrusive Rocks in the Neighbourhood of Eskdale (Cumberland), Q.J.G.S., Lxv> 1909, pp. 63 and 70. ? Holmquist, J. P, Studien tiber die Granite von Schweden. Bull. Geol. Inst, Upsala, vir, 1904-5, Nos. 13, 14, p. 116. ROCK SPECIMENS FROM CENTRAL AND WESTERN AUSTRALIA. 297 dark minerals, iron-ores, hornblende and biotite occur in intricate clusters, along with much apatite and a little zircon. The hornblende is almost opaque from dusty magnetite inclusions, is intimately penetrated by biotite and is embraced by compact iron ores, around which and in the bays of which biotite is freely developed. The rock may therefore be interpreted as a hornblende granite, probably belonging to the gneiss series. The second rock is labelled “10 miles EK. of Camp 33,” i.e€., from the east of the Barrow Range. Streich states - that the Barrow Range consists of eruptive granite, but mentions the occurrence ten miles east of the range of two small “isolated hills of granulite, which is distinctly stratified with a low angle of dip towards south.’’ Stelzner remarks of one of these specimens that “‘it resembles so closely the granulite of the Saxon granulite-ellipsis that it could have been found there as well.’”’ The present speci- men is distinctly banded in yellow and dark layers, and presents considerable superficial resemblance to the more yellow varieties of jaspers so abundant in the goldfields of Western Australia. It difiers from them, however, in a profusion of small red garnets, which when examined with a lens show no sign of crystal faces. In addition the lens reveals an abundance of an elongated well cleaved colour- less mineral with adamantine lustre. In section the latter mineral shows prismatic forms, with a perfect longitudinal cleavage, has straight extinction, positive elongation, and a birefringence considerably superior to that of quartz (between ‘015 and ‘020 according to Levy and Lacroix’s colour scale). Basal sections are approximately quadrate in shape, and by their study the mineral is shown to be almost uniaxial and optically posi- tive; the opening of the axial brushes is almost impercep- tible. An examination of tho crushed mineral in liquids of 298 J. A. THOMSON. known refringence prove the maximum refractive index to be in the neighbourhood of 1°658. This combination of properties precludes identification with any well known uniaxial mineral. To test the possibility of the mineral being phenacite, Mr. G. J. Burrows very kindly undertook a qualitative examination of the rock for beryllium, but with negative result. There isno common biaxial mineral of low axial angle which agrees in all the above characters, and as the amount of material was too small to permit of isolation and chemical analysis, the mineral must be left unidentified for the present. The other minerals present are quartz and orthoclase in large amount, magnetite in smaller quantity and occasional crystals of zircon. The yellow colour of the rock is due to Staining by limonite, the orthoclase in particular being striated by plates of this mineral along the cleavage planes. The quartz and orthoclase form an uneven grained mosaic with a limonitic cement, a structure which in many respects suggests a clastic origin. On the other hand the nearly constant orientation of the unnamed mineral, and an alter- nation of bands of clear mosaic with other bands containing magnetite and limonite points more strongly to a parallel structure developed in situ (Fig. 3, Plate XIV). It is reasonable to suppose that the rock is a member of the gneissose series. There is only one rock that resembles the rocks of the auriferous areas of Western Australia, and it is from the Cavanagh Range. The hand specimen is a light green aphanatic rock, which shows when wetted a few veinlets. of lighter colour. The section shows that it consists pre- dominatingly of fine grained albite and clinozoisite with smaller amounts of a pale actinolite, chlorite, sphene and accessory apatite. The felspars, in bundles of sub-radiating prisms, form a network within which the other minerals ROCK SPECIMENS FROM CENTRAL AND WESTERN AUSTRALIA. 299 lie in characteristic forms, clinozoisite and sphene in granules, actinolite and chlorite in more or less elongate prismatic forms. There are in addition a few nests of secondary quartz and epidote, while the veinlets are seen to consist of clinozoisite with a little sphene. The rock is a fine grained amphibolite, rather more felspathic than usual. Rocks very similar to this are of frequent occurrence in the goldfields of Western Australia, e.g., Kalgoorlie, Norse- man, the Murchison Valley, etc. They seem to form the country into which large dykes of coarse grained basic rocks, now also amphibolites, have been intruded, and may therefore be termed the older amphibolites. As a rule these fine grained amphibolites are not conspicuously auri- ferous, except near the contact of graphite or quartz- porphyry. The specimen, however, is of considerable importance in showing that the rocks of the known aurifer- ous belts are found as far eastwards as the Cavanagh Range. The remaining rocks are probably intrusive, though the interpetation of some is not without doubt. A rock from Skirmish Hill (22/7/91) is probably to be identified asa much altered quartz porphyry. The hand specimen is grey- black and aphanatic except for red phenocrysts of felspar. In section these phenocrysts are excessively turbid, but may be identified as orthoclase in many cases, although an acid plagioclase also appears to be present. Apatite occurs in large prisms of such size as to deserve the name of phenocryst, and magnetite also occurs in large grains. Much more abundant than the felspar is quartz, in very perfectly elliptical shapes. Sometimes these are occupied by one large plate of quartz, with a marked rim of dusty inclusions at a short distance from the margin, or a mar- ginal fringe of small grains, at other times by a mosaic of grains of smaller size. Though bearing much resemblance 300 J. A. THOMSON, to amygdules, these elliptical plates of quartz may perhaps be more correctly interpreted as corroded phenocrysts round which a secondary deposition of quartz has taken place. The groundmass consists ofa fine grained structure- less aggregate of quartz, turbid felsparand magnetite with an abundance of chlorite much stained by limonite. The rock is therefore a porphyry, and perhaps a quartz-porphyry. Streich states that Skirmish Hill is composed in the main of a porphyritic syenite. Another rock, certainly a dyke rock, is labelled Cavanagh Range. It isa dark grey, very finely crystalline rock in hand specimens. In section it is seen to be porphyritic, the phenocrysts being in part small euhedral prisms of red- violet, slightly pleochroic titaniferous augite, and in part much larger pseudomorphs of some earlier mineral. The pseudomorphs now consist mainly of chlorite (pennine) with a less amount of carbonates, sphene and flakes of tremolite. Their forms are distinctly suggestive of olivine, although if they represent this mineral, the alteration is an unusual one. The groundmass of the rock is made up largely of small prisms of brown-green hornblende, often green on the margin. They contain occasional small kernels of augite and are surrounded by short fibrous outgrowths of paler hornblende. Next in importance comes felspar in short multiply twinned lath-shaped or radially built forms. The low birefringence, refractive indices less than that of Canada Balsam, and extinction angles up to 15’, refer the Species to albite. Here and there large nests of yellow epidote are found, in whose neighbourhood the hornblende is chloritised and carbonates are abundant. Small iron ores are plentifully scattered throughout the groundmass; their form refers them to the magnetite group, while a partial alteration into sphene shows that they are titan- iferous (titanomagnetite). ROCK SPECIMENS FROM CENTRAL AND WESTERN AUSTRALIA. 30] The rock is certainly an augite-hornblende lamprophyre, probably a camptonite. It is the first rock of this class so far found in Western Australia.’ A rock of very peculiar character may be described here, as it has some faint resemblance to the camptonite just described, (Cavanagh Range, 31/7/91). It is probably the rock referred to by Streich as tachylite, of which Stelzner remarks :—*‘This rock is of such an extremely fine grain that I cannot determine it, even with the aid of the micro- scope on rock sections.’’ The hand specimen is a dark aphanitic rock with some superficial resemblance to a tachylite, but contains a few clear patches of quartz and small geodes containing pyrites. The section (Fig. 4, Plate XIV) shows a number of small elliptical and larger irregularly shaped areas formed of small rods of almost opaque material grouped together like bundles of faggots; between these bundles and acting as a cement are clearer areas consisting of irregular biotite flakes and an indeterminate green mineral in a fine grained quartz base, The green mineral possesses a higher birefringence and lower refringence than the biotite, but a similar absorption - and a pleochroism from opaque to dark green or yellow. It appears to be uniaxial or feebly biaxial, is optically nega- tive with positive elongation. The dispersion is very strong, comparable to that of chloritoid, from which, however, it differs in its direction of maximum absorption and its lack of polysynthetic twinning. Most often it occurs in shapeless plates, but occasionally gives lozenge-shaped sections. These differ from hornblende only in the absence of cleavage planes. The mineral thus appears to be intermediate between biotite and chloritoid in its characters, and may possibly be pseudomorphous after hornblende. 1 The rocks described as camptonites by Simpson and Glauert from the Philips River Goldfield appear to the writer to be really contact-altered amphibolites, Bull. 35, Geol. Surv. W.A., 1909, pp. 42-3. The faggot-like areas give an aggregate polarisation colours like those of carbonates, but under high magnifica- tion this is seen to be due to the presence of numerous minute flakes of biotite. The small rods appear most often to be opaque, but on the edges of the section they are seen to consist of the green mineral described above. Finally there are a few elliptical areas like amygdules, consisting of coarse grained quartz and large flakes of bictite. 302 J A. THOMSON, The interpretation of such a rock is impossible without field work to fix its geological nature, and in case it is an alteration product, to enable one to trace stages from some recognisable form. Assuming the small rods to be pseudo- morphous after hornblende, the rock might represent a fine grained amphibolite or more likely a camptonite such as that described above. Such an assumption is, however, little removed from guesswork. The rock is certainly not a tachylite. The remaining ten rocks, though not all from the same locality, form a distinct and related group. They show a graduated mineral composition, and differ chiefly in grain size. They are remarkable for the freshness of their felspars and pyroxene, and although the olivine and iron ores are at times somewhat altered, there is no sign of saussuritic, sericitic, chloritic or epidotic alteration pro- ducts. They must, therefore, be assumed to be of much later age than the gneissose, and probably also the dyke rocks, just described. They are for the most part holocrystalline, coarse grained and almost black, the felspars being so transparent as to affect the colour of the rock very little. The mineral composition is that of gabbros or norites, but on account of the perfect ophitic structure displayed, the term dolerite is preferable. The more basic rocks contain much olivine, the most acid contain free quartz in micro- pegmatite, while the whole series is characterised by the ROCK SPECIMENS FROM CENTRAL AND WESTERN AUSTRALIA. 303 small amount of iron ores and a great richness in ferro- magnesian minerals, viz. olivine, hypersthene and enstatite augite. The following table shows the mineral composition, the rocks being arranged approximately in order of their basicity :— ra LS) PS (St) | cS rent ao i [=>] * i sk 8 Olivine ee Sheets) ch Hypersthene ... | ial Enstatite-augite a8 net Augite... 2, se (cea A i 7 + T * | —-t- Pyroxene-perthite ...) — Hornblende A. Biotite... Iron ores Apatite Plagioclase * Ok Kb ee | 2 = ie < *—-I- «| re ||

has elaborated this view with special regard to quartz-dolerites, and suggests further that they represent a critical stage in assimilation, in that they are almost entirely made up of intergrowths of related minerals, and have reached the limit of saturation of a basic magma with quartz. Both these writers totally fail to explain the excess of magnesia and iron over non-felspathisable lime which is necessary for the formation of hypersthene or enstatite-augite. Whether we admit with them that quartz- dolerites have arisen by the assimilation of acid material by a basic magma, or agree with Vogt that they have arisen by differentiation as an ‘“‘anchi-eutectic”’’ rock, we must still postulate that the primary magma had funda- 1 Daly, R. A., The Secondary Origin of Certain Granites, Am. Journ. Sci., xx, 1905, pp. 185 - 216. * Tyrell, G. W., Geology and Petrology of the Intrusions of the Kilsyth-Croy District, Dumbartonshire. Geol. Mag., Dec. 5, Vol. vit, 1909, pp. 295 - 309 and 359 — 366. 314 J. A. THOMSON. mental chemical peculiarities to allow it to give rise to a secondary magma capable of producing these minerals, instead of common augite. It is this chemically peculiar primary magma which is necessary for the establishment of a petrographical province. A further line of evidence which strengthens the writer’s suggestion is the recurrence of quartz-dolerites at different geological ages in some of the above fragments of Gondwana Land. Owing to their degree of alteration, it is not possible to assert that the older groups also contained enstatite- augite, but analyses support the view. This phase of the subject is too extended to discuss at length here, but the following facts may be instanced. Among the Western Australian amphibolites of supposed pre-cambrian age there are rocks which can be shown to be merely uralitised and saussuritised quartz-dolerites." Henderson’ has described similar rocks from the Transvaal, which may be assumed to be much older than the Karroo dolerites. In India, the important fragment of Gondwana Land from which Mesozoic quartz-dolerites have not been noted, there is a well known occurrence of the rock in the Cuddepah, and in these Wahl has shown the presence of enstatite- augite. But there is also in the Archzean of India the — peculiar group of charnockites which exhibit, not indeed the same structural peculiarities but very similar chemical relations, viz. a high proportion of magnesia and iron com- pared to non-felspathisable lime combined with an excess of silica.* | * Thomson, J. A., Petrographical Notes to Bull. 38, Geol. Surv. W.A., 1909, pp. 137, 145, 151, and 156. 2 Henderson, J. A. L., Petrograpical and Geological Investigations on certain Transvaal Norites, Gabbros and Pyroxenites, London, 1898, pp. 29 — 33. * Holland, T. H., On Augite Diorites with Micropegmatite in S. India. Q.J.G.S., 111, (1897) p. 405. Wahl, loc. cit. ; * Hoiland, T. H., The Charnockite Series, a group of Archean Hypers- thene Rocks in Peninsular India. Mem. Geol. Surv. India, xxvu1., Pt. 2, pp. 119 - 249, 1900. ROCK SPECIMENS FROM CENTRAL AND WESTERN AUSTRALIA. 315 Whether the similar recurrence of these rocks at different periods of geological history will be found so abundantly elsewhere as to invalidate the force of this argument, so far as it applies to the rocks of Gondwana Land, remains for the future to disclose. In so far as it applies to Aus- tralia, it opens up a fruitful field of enquiry for Australian petrologists. NOTE.—Since the above was written, an important paper by Dewey and Flett has made suggestions that to some degree undermine the above views.’ In effect, they pro- pose to recognise besides the well known Atlantic and Pacific suites of rocks yet a third known asthe spilitic, and geographically associated with districts of long continued and gentle subsidence. The rocks characterising the suite are picrite, diabase (often albitised), minverite, quartz- diabase, keratophyre, soda felsite and albite granite. The most striking chemical peculiarities of the group are the richness in soda compared to potash and lime, not indeed always to be seen in the original minerals, but betrayed by the juvenile albitisation that the rocks have undergone. Quartz-dolerites, then, are claimed by them as belonging, at least in part to the spilites, both on account of the albitisation which they sometimes exhibit and of their geological relationships with other members of the suite, whereas in the ideas put forward above, they are attached to the charnockite suite on account of their relative rich- ness in iron and magnesia. It must be admitted at once that the above authors have a far stronger case for their general view, based as it ison a much greater body of observation. There are even features in Western Australia that give support to the possibility of the spilite suite being 1 Dewey, H., and Flett, J. S., British Pillow-lavas and the Rocks associated with them. Geol Mag,, Dec. 5, Vol. viti, 1911, pp. 202-9 and 241-8. 316 J. A. THOMSON. developed there, viz. the occurrence of albite granites and the presence of albitisation amongst the older (amphiboli- tised) quartz-dolerites. If, on the other hand, the commonly occuring rock types are correctly accounted for as anchi- eutectic rock, as many authors are now willing to believe, there would be a tendency for the development of similar rocks from widely different primary magmas. That such ‘diphiletic’* rocks are present in the case of the Atlantic and Pacific suites has been consistently denied by Rosen- busch, but even he is unable to ascribe most basalts to one or the other suite, and other observers believe in the possibility of diphiletic rocks. It would not do to push this possibility too far in connection with the views suggested above, or the primary chemical peculiarity postulated above would not be deducible from such a diphiletic anchieutectic rock, Summary and Conclusions. A series of seventeen rocks collected by the Hlder Scien- tific Exploring Expedition from the neighbourhood of the eastern boundary of Western Australia are described in detail, and compared with the rocks of the Western Aus- tralian goldfields. Only one resembles the immediate country of the auriferous veins. 'T'wo are probably to be referred to the gneiss formation. The remainder are dyke rocks; they include a camptonite, the first undoubted occurrence of this type in Western Australia, and a num- ber of very fresh intrusive dolerites of considerable petro- logical interest, especially in that they are the first rocks on the Australian mainland in which enstatite-augite and pyroxene-perthite have been recorded. A comparison of these rocks with the later dykes of Western Australia and the dolerite sills of Tasmania, Antarctic and South Africa 1 Tam not aware whether the term diphiletic has been used before in this sense. It was suggested to me in conversation by Dr. J. S. Flett. ROCK SPECIMENS FROM CENTRAL AND WESTERN AUSTRALIA. j 317 is made, and the suggestion is put forward that they are of the same age and magmatically related. The results obtained from this small collection are sufficient to show that the whole official collection, con- sisting of some hundreds of rocks is worthy of a fresh examination in the light of the recent knowledge acquired in the Western Australian goldfields. Presumably the collection is in the possession of the Royal Society of South Australia. EXPLANATION OF PLatTe XIV. Fig. 1. Banded norite, Fraser’s Range, Western Australia, Natural light. Magnified 15 diameters. ,» 2. Hornblende granite-gneiss, Blyth Range, Central Australia. Crossed nicols. Magnified 15 diams. 3. Granulite, Barrow Range, Central Australia. Natural light. Magnified 15 diams. 4. So-called tachylite, Cavanagh Range. Natural light. Magnified 15 diams. ,, 9. Pyroxene-perthite in quartz dolerite, No. 14, Near Depdt 1. Crossed nicols. Very highly magnified. 6. Hypersthene olivine dolerite. showing ophitic structure of both olivine and hypersthene towards felspar, No. 8, Hills near Camp 5, 20/6/91. Natural light, Magnified 15 diams. 318 F. B. GUTHRIE. A SUGGHSTED EXPLANATION OF ALLOTROPISM BASED ON THE THEORY OF DIRECTIVE VALENCY. By F. B. GutTHRig, F.1.c., Department of Agriculture. [Read before the Royal Society of N. S. Wales, December 6, 1911. | THE suggestion that valency is due to the transference of corpuscles from one atom to the other, and that in conse- quence the valency bonds familiar to chemists in the graphic representation of molecular structure may be regarded as having definite direction, was first put forward by Sir J. J. Thomson.* This hypothesis is enunciated by him in the following terms: ‘‘For each valency bond established between two atoms the transference of one (negatively charged) corpuscle from one atom to the other has taken place, the atom receiving the corpuscle acquiring a unit charge of negative electricity, the other by the loss of a corpuscle acquiring a unit charge of positive.’’ Sir J. J. Thomson regards each of these transferences as a “unit tube of electric force between the two atoms, the tube starting from the positive and ending on the negative atom.”’ The connecting links between the atoms which are usually represented by straight lines would then be replaced by arrows indicating the direction taken by the corpuscles, namely from the more positive to the more negative atom. Compounds, such as marsh gas and tetrachlormethane would be represented thus :— + The Corpuscular Theory of Matter, pp. 138, 139. ALLOTROPISM BASED ON THE THEORY OF DIRECTIVE VALENCY. 319 Cl aa Cl Sir Wm. Ramsay in his Presidential Address to the Chemical Society 1908,’ has further elaborated this hypothesis and has suggested that electrons are atoms of electricity and serve as the *“‘ bond of union’”’ between atom and atom. He explains the constitution and ionization phenomena of complex inorganic salts, such as nitrites of the cobaltammines by this hypothesis. This extremely interesting suggestion has been pursued further by K. G. Falk and J. M. Nelson,” who have shown that many cases of isomerism amongst carbon compounds ean be explained by this hypothesis as well as by spacial configuration. They have shown that this method of repre- senting the relation between the atoms can be applied to earbon compounds with triple and double bonds, nitrogen compounds with single and double bonds, and compounds containing double bonds between unlike atoms. Falk’ has further applied this hypothesis to the ionization relations of organic acids. The object of the present communication is to attemp to apply this hypothesis to an explanation of the structure of allotropic forms of the elements. In the case of the isomers of organic and inorganic com- pounds, the assumption of valency direction provides a possible second explanation of such isomerism for which a satisfactory explanation is already forthcoming in the + J.C.S., Vol. 98, Trans. p. 774. 2 K. G. Falk and J. M. Nelson, Journ. Amer. Chem. Soc., 32, 1637. 3 K. G. Falk, Journ. Amer. Chem. Soc., 38, 1140. 320 F. B. GUTHRIE. spacial grouping of the atoms. In the case of allotropism, no satisfactory explanation has yet been advanced, and any hypothesis which will explain this phenomenon must have a profound bearing on our conception of molecular structure. The hypothesis most generally accepted to account for allotropism is that it is due to the ability of the element to form molecules of varying numbers of atoms. This is true, for instance, in the case of oxygenat ordinary temperatures, and experimental proof is available of the condensation in the case of the ozone molecule, but attempts to account for other cases of allotropism in the same way have not been successful. Erdmann’ assumes a molecular structure S;, for the second dark liquid form of sulphur, on the analogy of oxygen, and proposes for it the name “‘thiozone.”’ This form is, however, a phase and not an allotropic form, and is dependent on temperature. There is no experimental proof that the sulphur molecule breaks up into any other than S, molecules. In the case of other elements, this variation in the num- ber of atoms composing the molecule is only observed in the state of vapour. Such variations, when observed, depend upon the temperature, (and, in the case of sulphur at its boiling point, on the pressure), and afford no explanation of different physical forms existing at ordinary tempera- tures and pressures. Iodine, for example, which forms no allotropes, varies like sulphur in respect to the molecular constitution of its vapour at different temperatures; at 600°, the molecule of iodine contains two atoms, whereas above 1,500", itis monatomic. This variation in the vapou density does not constitute allotropism. . In the case of isomerism amongst organic compounds, the direction taken by the negatively charged corpuscles depends upon the relative electric conditions of the neigh- ? Erdmann, Annalen, 1908, 362, 133. ALLOTROPISM BASED ON THE THEORY OF DIRECTIVE VALENCY. 321 bouring atoms. What, however, happens when, as in the case of an element, the atoms composing the molecules are the same? Isit possible that valency direction is affected by the conditions under which the molecules are formed ? The assumption that variation of the conditions attending the formation of the molecule may alter the relative direction of the ‘tubes of electric force,’’ the directions in which the electrons are discharged, will account for variations in the structure of the resulting molecule which may possibly havea bearing,on the different physical forms which the molecule is capable of assuming. In what follows, the data concerning the molecular weights and allotropic forms of the elements are taken for the most part from Roscoe and Schorlemmer’s ‘Treatise on Chemistry,’’ Vol. 1, 1905. All other references quoted have been verified. SULPHUR. The molecular weight of sulphur as determined by the freezing point depression and boiling point elevation of solutions in carbon-bisulphide and naphthalene, corresponds to a molecule consisting of eight atoms. The vapour density diminishes rapidly with increase of temperature, until at 860° it corresponds with the formulaS., and remains constant up to 1400°. At temperatures nearer the boiling point of sulphur (400°) the vapour-density is nearly constant at pressures between 540 mm. and 125 mm., and corres- ponds to a formula between S., and S,, the molecular weight diminishing rapidly with reduced pressure at this temper- ature. Itappears most probable that the sulphur molecule contains eight atoms at lower temperatures, splitting up into S. molecules as the temperature rises (or at 440° with diminished pressure). With regard to its valency, sulphur is divalent in its principal compounds with hydrogen and the metals, occas- T—Dec. 6, 1911. —— 322 F. B. GUTHRIE. ionally tetravalent (in SCl,), and hexavalent (SF;). The molecule of sulphur may therefore be represented by the graphic formula :-— 5 ye PN nae oe \ iniellaaiagl ena: If now we indicate direction in the various bonds and replace the straight lines by arrows showing the direction in which the electrons are projected towards the neighbour- ing atom, we shall be able to produce a large number of possible figures representing the structure of the different molecules formed by variations in the valency direction. It is fair to assume that the transference of corpuscles takes place only between the atoms within the molecule and that corpuscles are not discharged beyond the molecule, which would result in its disintegration. It is further demonstrable that if a greater number of electrons travel in the one direction than in the other, (except in the case in which they all travel in the same direction) the result is unsymmetrical, and presumably unstable. We thus reduce the number of possible figures to about forty, of which only four are symmetrical, namely :— 1. In which all the corpuscles travel in the same direc- tion, represented by the formula (aaaaaaaa). 2. In which each alternate bond represents a corpuscle travelling in opposite directions, represented by the formula (ab ab ab ab). - 3. In which a pair of neighbouring bonds represents cor- puscles travelling in one direction (a) alternating with a pair travelling in the opposite direction (b) represented by the formula (aa bb aa bb). ALLOTROPISM BASED ON THE THEORY OF DIRECTIVE VALENCY. 323 4. In which four neighbouring bonds representing cor- puscles travelling in one direction (a) are’ followed by four travelling in the opposite direction (bh), represented by the formula (aaaabbb b). Oase 1 is represented by the graphic formula :— 1) es E Ch) Fiatane %S S + J Se pe SS) Each atom has lost a corpuscle (a unit of negative elec- tricity) to one of the neighbouring atoms and has gained one from the other neighbouring atom, the result being a symmetrical stable molecule in which the electrical charge on each atom is neutralized. | Case 2 is represented as follows :— Cies—>s$_ Lf uN a) S +2 a) +e -2 \ re 8, In this case each alternate atom receives two negative corpuscles, acquiring two unit charges of negative elec- tricity, and loses two negative corpuscles, acquiring two unit charges of positive electricity, the result being a symmetrical stable molecule in which the electrical charge is evenly distributed. 324 F. B. GUTHRIE. Case 3 is represented as follows :— (3) e —- SS °S -2 In this case, one of the upper and lower atoms have each lost two corpuscles becoming in consequence charged with two unit charges of positive electricity, one of the right and left hand atoms have acquired two unit charges of negative electricity, and the intermediate atoms have gained and lost a negative corpuscle and are consequently neutral. Case 4 is represented as follows :— +2 0 4) [§> Ss 1k \ i S : o va oo 5 —2 Here again we have a molecule of symmetrical structure in which the positively charged atom in one part of the molecule is balanced by the equally negatively charged atom in the other, but its configuration suggests that it is probably more readily altered than the previously figured molecules in which the electrical charge is more evenly divided. It may represent one of the less stable modifica- tions, probably the plastic variety. We have here figures that may not unreasonably be regarded as representing the four comparatively stable modifications of the element sulphur. The viscid modifica- ALLOTROPISM BASED ON THE THEORY OF DIRECTIVE VALENCY. 325 tion need not be taken into account, as its formation is dependent upon the temperature, and it can hardly be regarded as a true allotrope. Any other graphic repre- sentation indicating valency direction will be found to yield either an unsymmetrical molecule or one of the forms already figured. PHOSPHORUS. In the case of phosphorus, we have an element whose molecular weight calculated from its vapour density at 444°8° is 126°6, corresponding to the molecular formula P,.* Mitscherlich, and Deville and Troost obtained the molecular weight of 123°84 at the temperature of 515° and 1040° {Roscoe and Schorlemmer). © Determination of the molecular weight from the raising of the boiling point of solutions of phosphorus in carbon bisulphide,” and the depression of the freezing point of solu- tions in benzene,’ further prove that the molecule consists of four atoms. If we regard phosphorus as a trivalent element we shall have as the ordinary representation of the phosphorus molecule P P = If now we assign valency direction to these bonds we get twelve possible cases, assuming as in the case of sulphur that the transference of electrons takes place only between the atoms of the molecules. We obtain :— Case A. when the double bonds travel in the same direc- tion (aa). This gives rise to three variations according as the single bonds travel— * Chapman, Journ. Chem. Soc. 1899, Trans. Vol. 75, p. 734. * Beckmann, Zeitschr. Physik. Chemie, 1890, 5, p. 76. * Hertz, ibid., 6, p. 358. “i beh. 326 ; F. B. GUTHRIE. 1st, both in the same direction as the double bonds (a) 2nd, both in the opposite direction (b) 3rd, one in the same direction with the double bonds (a) and one in the opposite direction (b). Case B. The double bonds travel, one pair in the direction (aa), the second pair in the direction (bb). There are three combinations possible, as in the previous case. 1st, :in which both single bonds travel in the same direction (a) 2nd, in which both single bonds travel in the same direction (b) 3rd, where the single bonds travel in opposite directions (a and b). Case ©. One pair of the double bonds travels in the same direction (aa), the second pair travels, one in the direction (a) the other in the direction (b). This also permits of three combinations according to the direction of the single bonds. Case D. The individual bonds in each pair of double bonds travel in different directions (ab) (ab). Giving rise as before to three modifications depending on the direction of the single bonds. Out of the twelve figures which it is possible to construct we get only the following figures which are symmetrical. (1) | | This is Case Al, in which double and single bonds all have the same direction, resulting in a symmetrical stable molecule in which the electric charge is evenly distributed. ALLOTROPISM BASED ON THE THEORY OF DIRECTIVE VALENCY. 327 (2) This is Case A2, in which the single bonds travel in the Same direction, but in‘a direction opposite to that in which the double bonds travel. We have also (3) +1 P ace ie A modification of Case D. (supra) in which the individual bonds in each pair of double bonds travel in opposite direc- tions, (a and b) and the single bonds travel in the one direction (a). This is identical with figure (1). (4) ,P SS P. In which the double bonds travel as in (3), and the single bonds travel both in the same direction, (b) opposite to that in which they travel in Figure 3. This is also identical with Figure 1. Figures 3 and 4 are identical with figure 1, so that there remain only the two possible combinations, figures 1 and 2 : which result in symmetrical molecular structures. These may be assumed to represent the yellow and red varieties respectively. All other combinations result in unsym- 328 F. B. GUTHRIE. metrical molecules overloaded in one portion with negative or positive electricity. This agrees with the conclusion of Chapman’ as to the existence of only two allotropes of phosphorus, and excludes the existence of the so-called ““metallic phosphorus,’’ produced by dissolving phosphorus in lead as an independent allotropic form. It is probable that ‘‘metallic’’ phosphorus and red phosphorus are identical, only the former is better crystallised. Schenck’s phosphorus, or scarlet phosphorus’ is also excluded. This substance is obtained by heating phosphorus in PBr;, and has not been prepared ina pure state. It appears most likely that it consists of a mixture of a solid hydride of phosphorus and ordinary phosphorus. SELENIUM. According to Saunders,’ the following well defined modifications of this element exist :— 1. Amorphous, vitreous, and soluble or colloidal. These are all soluble in carbon bisulphide. They differ in appear- ance, but may be regarded as belonging to the same allotropic form, and are classed by Saunders under the name of “liquid selenium.”’ 2. Red crystalline selenium. This occurs in two closely allied but distinct crytalline forms, soluble in carbon -bisulphide. 3. Crystalline grey or “‘ metallic selenium.”’ This is the stable form, and is insoluble in carbon bisulphide. There thus exist, as in the case of sulphur, four definite forms, for though the red crystalline forms both belong to the monoclinic system, measurements of the crystals made by Mitscherlich and later by Muthmann (both quoted by * Chapman, Journ. Chem. Soc. Trans. 1899, Vol. 75, p. 734. 2 Journ. Soc. Chem. Ind., 1903, Vol. 22, p. 1226. > Saunders, Journal Physical Chemistry, 1900, 4, 423. ALLOTROPISM BASED ON THE THEORY OF DIRECTIVE VALENCY. 329 Saunders) show that they crystallise in different forms of different stability, one of which is isomorphous with mono- clinic sulphur. The third allotrope (metallic selenium) is the stable form into which the red crystalline forms pass over on heating to 170°—180°. The crystalline forms are produced from the amorphous variety when the latter is dissolved in carbon bisulphide. With certain solvents, such as quinoline, amorphous selenium is converted directly into the metallic modification. The vapour density of selenium diminishes very rapidly with the temperature and its behaviour resembles very closely that of sulphur. Selenium boils according to Deville and Troost at 665° under 760 mm. The vapour density, as determined by Szarvasy' at 774° corresponds to a molecular formula between Se, and Se;. Between 900° and 1800° the vapour density is constant at 78°6 and corresponds to the formula Se. It is extremely probable that at temperatures closer to the boiling point, the molecule would be very much larger as in the case of sulphur, which selenium so closely resembles. It is to be noted that in the case of sulphur the vapour density observed at 606° (which is only 160° above its boil- ing point), corresponds to the molecular formula 8,, whereas at 440° the molecule is 8. In the case of selenium, the temperature (774°) at which the vapour density corresponds to the molecular formula Se, is more than 100° above its boiling point, and we are justified in expecting that at lower temperatures the number of atoms in the molecule would increase as in the case of sulphur. } Szarvasy, Berichte, 1897, 30, 1244. * Biltz, Zeitsch. Physik. Chemie, 1896, 19, 4, 15. 330 F, B. GUTHRIE. Beckmann and Pfeiffer’ have determined the molecular weight by observing the depression of the freezing point of solutions of selenium in phosphorus, and find that this corresponds to the molecular formula Ses. We are therefore justified in assuming that the selenium molecule is of similar construction to the sulphur molecule | and consists of eight atoms. Like sulphur also, the selenides of hydrogen and the metals have the formula Se’M,. If therefore, we ascribe direction to the uniting bonds repre- senting valency, we obtain as in the case of sulphur four possible combinations, in which the electric charges on the individual atoms are either neutralised or evenly distributed, producing four symmetrical, more or less stable molecules, corresponding to the four definite allotropic forms. If further speculation is permissible, one would be tempted to suggest that the most stable form (metallic selenium) might be represented by the neutralised molecule (corresponding to Case 1 of sulphur) and that the less stable crystallised modifications are represented by figures similar to Nos. 3 and 4, in the case of the sulphur molecule. TELLURIUM. In the case of tellurium, the information is more meagre and the conclusions less satisfactory. Apparently only two allotropic forms of this element are recognised, namely the crystallised form occurring in hexagonal riombohedra, with a silvery lustre, and the amorphous variety produced when solutions of the oxide are reduced by sulphurous acid.” Gutbier® has obtained two colloidal modifications of tel- lurium, a brown one obtained on reduction of solutions of tellurium dioxide and telluric acid, and a bluish-green one formed only on the reduction of telluric acid. Whether 2 Fabre and Berthelot, C.R. 104, 1405. _ 5 Gutbier, Zeitsch. Anorg. Chemie 1902, 32, 51. ALLOTROPISM BASED ON THE THEORY OF DIRECTIVE VALENCY. 331 these differences in colour are due to the state of suspension or to variety of allotropic forms he leaves an open question in view of the present state of our knowledge as to the colloidal condition of the elements. On passing an electric current through solutions of telluric acid in the presence of potassium cyanide, Gutbier and Resenscheck’ obtain a brown violet liquid hydrosol. If ammonium oxalate is used instead of potassium cyanide the solution becomes steel- blue. If the brown solution is hydrolised before metallic tellurium is produced the solution of hydrosol is permanent. With regard to the molecular weight of tellurium there is an equal difficulty. The only determinations of the vapour density quoted are those of Deville and Troost,’ who found the vapour density at 1390° to be 9, (Air=1 Biltz’ finds this number, (which corresponds to the formula Te.) to be correct at 1800 degrees. At the same time Biltz considers that Deville and Troosts’ conclusions are certainly incorrect, and that at lower temperatures, tellurium vapour has a much higher specific gravity, and like sulphur and selenium, the molecule contains a greater number of atoms, splitting up into smaller molecules at higher temperatures. There are no determinations, as far as Ihave been able to ascertain, of the molecular weight of tellurium by other methods. The data therefore, in the case of tellurium both in respect to the number of allotropic forms and the molecular weight are not sufficiently reliable to enable us to speculate on the connection between thetwo. If we assume that only two allotropic forms exist, and that the formula is correctly represented by the vapour density at 1390° and above, and is Te., then we have the very simple explanation that under these circumstances two and only two modifications are possible, namely :— 1 Gutbier and Resenscheck, Zeit. Anorg. Chemie, 1904, 40, 264. 2 C.RB., 1863, 56, 891, | 3 Biltz, Zeitschr. Physik. Chemie, 1894, 19, 415. 302 F. B. GUTHRIE. 2 ° +2 — Oo Temas re Teste If, however as seems more probable, tellurium follows sulphur and selenium, and the molecule at lower tempera- ture more nearly approaches the formula Tes, then we are confronted with the question whether there are not more than two allotropic forms of the element. If the molecule is octatomic and the atom divalent, then as in the case of sulphur and selenium we would require four allotropic forms if the allotropy is conditioned by the direction of valency. Itis possible, of course, that the two recorded colloidal forms are true allotropes, or that there are other allotropic forms not yet isolated. Tellurium is still a some- what rare element, and its properties have not yet been studied with the thoroughness and care accorded to sulphur. ARSENIC, The arsenic molecule like that of phosphorus is tetra- tomic. At 860° the vapour density is 146°88 corresponding toa molecular weight of 293°8 = As, At higher tempera- tures, 1600° — 1700°, the vapour density diminishes by nearly one-half and the molecule only contains two atoms. Its molecular weight as determined by the elevation of the boiling point of solutions of yellow arsenic in bisulphide of carbon, corresponds also to the formula As, We may - therefore assign to it a formula similar to that of the phosphorus molecule. Agi=e= As With regard to its allotropes, the number of these has not been definitely established. In addition to the steel-grey crystalline form obtained by reduction of the oxide and ALLOTROPISM BASED ON THE THEORY OF DIRECTIVE VALENCY. 333 sublimation, and the amorphous black variety formed when arseniuretted hydrogen is strongly heated, the following forms have been noticed by different observers. When arsenic is sublimed in hydrogen it is said to be split up into acrystalline form, an amorphous form, anda yellow vapour depositing grey crystals. These forms are deposited at different distances from the source of heat. An extremely unstable, but, according to Erdmann and Unruh,’ a definite yellow crystalline variety is obtained when arsenic vapour is strongly cooled and led immediately into carbon bisulphide in which it is soluble. It is very rapidly converted at ordinary temperatures and by light into the black variety, and it is only possible to keep it permanently in complete absence of light and at a tempera- ture of —65° to - 70°. Erdmann and Unruh (loc. cit.) also find that a reddish- brown precipitate separates out very slowly from a solution of the above yellow arsenic in carbon bisulphide. The substance has not been obtained free from sulphur nor has it been obtained in sufficient quantity to enable it to be identified by a specific gravity determination. Reviewing the information available, there appear to be certainly two well defined and distinct allotropic forms of arsenic, the crystalline and the amorphous. _ The molecular structure of these may be regarded as corresponding to those suggested for yellow and red phos- phorus. There may be more than one crystalline form, but the information on this point is not definite. The yellow variety of arsenic is exceedingly unstable and might be represented by one of the eight unsymmetrical forms which are producible according to the hypothesis advanced. It appears probable that the red-brown form is not anallotrope at all. * Erdmann and Unruh, Zeitsch. Anorg. Chemie, 1902, 32, 437. 334 F. B. GUTHRIE. If the two crystalline forms obtained on subliming arsenic are identical or form only one allotrope, then arsenic falls definitely into line with phosphorus, and the two stable allotropic forms (crystalline and amorphous), may beassumed to have the same molecular structures as are assigned above to yellow and red phosphorus. CARBON, SILICON, BORON. Speculation on the foregoing lines is not justified in the case of these elements, whose molecular weights have not yet been ascertained with certainty. In the case of carbon it appears probable that the molecule consists of twelve atoms or some multiple of twelve. A representation of a twelve-atom molecule, the atoms of which are tetravalent obliges us to recognize more than three stable symmetrical forms if freedom of direction is assumed for the corpuscles exchanged between the atoms. Conclusions. It would appear that the corpuscular theory of valency, involving valency direction, may afford a possible explana- tion of certain cases of allotropism among the elements. It is suggested that the relative directions of the discharged electron or “‘valectron’’ may be due to the condition under which the molecule is produced. Variation in the direction of these corpuscles gives rise to molecular figures which differ from each other in the manner in which the electric charge is distributed amongst the atoms. Those molecules in which the electric charge is neutralized or symmetrically distributed, may be regarded as being more or less stable molecules and as representing the various allotropic forms of the elements. It is not suggested that this is the sole cause of allotropy nor that it supplies an explanation in all cases. The case of oxygen and ozone would appear to be sufficiently explained by molecular condensation. . ALLOTROPISM BASED ON THE THEORY OF DIRECTIVE VALENCY, 335 The only assumption made which is unsupported by experimental proof is that of the valency-values assigned to the several elements under discussion. It is now generally accepted that the valency of any given atom depends upon the nature of the atoms with which it combines and is consequently a variable property. Sulphur for example is divalent towards hydrogen, tetra- valent towards chlorine and hexavalent towards fluorine. Valency is not even a constant quantity towards the same element, thus manganese forms MnCl,, MnCl,, MnCl, ete. No experimental evidence is available concerning the valencies of the atoms of an element in combination with atoms of the same element, and the assumption has been | made that these are the same as those which the elements exhibit towards hydrogen a.‘d in their principal compounds, and which are suggested by their positions in the periodic table of the elements. Sulphur, selenium and tellurium have been assumed to be divalent, arsenic and phosphorus trivalent. Such an assumption does not contravert the theory of variable valency. In the case of sulphur, selenium, and phosphorus, the hypothesis would appear to offer a reasonable explanation of the observed facts. Inthe case of tellurium and arsenic the data are not sufficiently unimpeachable to justify an extension of the argument to their case though it appears probable that they will be found to follow the examples of sulphur and phosphorus respectively. In the case of carbon, silicon, and boron, our inability to visualize the molecule prevents our speculating on these lines. A point of considerable interest in this connection is that allotropic forms do not exist among the non-metallic elements which are monovalent, (such as hydrogen and the halogens), nor among those which are monatomic (helium, 336 F. B. GUTHRIE. neon, argon, krypton, xenon). All the other non-metallic elements, with the single exception of nitrogen,’ form allotropes. These facts tend to support the hypothesis here put for- ward, since, in the case of monovalent elements, variation in the direction of the discharged electron produces no alteration in the structure of the resulting molecule. = | + | e e ° . +] — | l i H H is identical with H 4 With monatomic molecules there can also be no change of direction. In the case of the metals, allotropy, where it exists, as in tin, is a function of the temperature. Deter- mination of the vapour densities of cadmium, mercury and zinc show that the molecules of these elements are mona- tomic. Mensching and Meyer have shown that. this is also the case with bismuth. Tammann’ has shown further that at — 40° (using the method of depression of the freezing point of mercury) nearly all the metals have monatomic molecules. My thanks are due to Mr. G. H. Knibbs, c.M.c., Common- wealth Statistician, for his kindness in verifying and abstracting certain references which I was unable to refer to locally. Also to Mr. L. Cohen of the Chemist’s Branch of the Department of Agriculture, for preparing the diagrams which illustrated the reading of this paper. 1 A chemically active modification of nitrogen has been described by R. J. Strutt, (Bakerian Lecture, Proc. Roy. Soc., 1911, A. 85, 219). 2 Berichte, 1889, 22, 726. $ Tammann, Zeit. Physik. Chemie, 1889, 3, 441. THE NATURE AND ORIGIN OF GILGAI CUUNTRY. 337 THE NATURE AND ORIGIN OF GILGAI COUNTRY (With NOTES ON QUATERNARY CLIMATE). By H. I. JENSEN, D.Sc. [Read before the Royal Society of N.S. Wales, December 6, 1911. ] I. Nature of Gilgais. Gilgai country is remarkably uneven country, consisting of alternate hummocks and hollows. It occurs in its characteristic form only on the western side of the Dividing Range. Gilgai country has a similar appearance to the *‘melonhole’ country of the coastal swamps and the ‘ crab- hoiey’ country of the tablelands, but the irregularity of the surface is much greater than these types. Sometimes in the western country we get the terms ‘ melonhole’ and ‘crabhole’ applied to the gilgai areas in which the irregu- larity of the surface amounts only to a difference of two or three feet between the tops of the hummocks to the bottoms of the depressions. The genuine ‘gilgai’ country is much rougher. The difierences in elevation between the knolls and the hollows amount to ten, fifteen and even twenty feet. The hummocks are sometimes of rounded outline, but more often they are irregular in shape, usually serpentine, vermiform or variously ramified. The depressions have also correspondingly irregular shapes. The depths of the hollows may be very variable within a comparatively small area. For some time after rain they contain stagnant water. The angle of slope from the summit of a knoll to the bottom of the adjacent depression may be anything from 10° to 60°. In typical brigalow gilgai country a sec- tion of the surface would consist of a very wavy line, the crests from 25 to 50 feet apart, and the hollows LO to 20 V—Dec. 6, 1911. 338 H. I. JENSEN. feet deep, quite deep enough to obscure a horse and its rider from the view of an observer ona hummock 10 yards away. The hollows vary in length from 25 to 50 or even 100 feet. The country is far too rough to ride over even when cleared. Gilgai country may occur in small areas of only a few acres, but where typically developed a gilgai area has fre- quently an extent of several square miles, and along the northern edge of the Pilliga Scrub these gilgai areas occur close together, separated from one another by narrow belts of red soil, and of light sands lining the creek courses, over an area about 25 miles long and 5 to 10 miles wide. This portion of the Pilliga Scrub we can call the ‘Gilgai Belt.’ It has an area of about 200,000 acres, adjacent to the towns of Narrabri and Wee Waa. The gilgai lands are, I believe, on the average more low- lying than the belts of red soil and the diluvial sands of the aggraded creek banks. Jam informed that a heavy flood inundates all the gilgai country before the red soil belts and sandy belts are flooded. II. Distribution of Gilgai Country. As far as 1am aware no description of ‘gilgai’ country has ever been published, but it has often been observed by surveyors and scientists in different parts of the State. Mr. R. H. Cambage, L.S., F.L.S., informs me that he has traversed gilgai country in many districts, and that, accord- ing to his experience, it is found in various places along the western slopes, north, central and south. It occurs usually near the white box belt, the zone of Eucalyptus albens. Mr. HK. C. Andrews, B.A., has had a similar experience of the distribution of typical gilgai country. He has informed me that he has only met with this type of surface on the THE NATURE AND ORIGIN OF GILGAI COUNTRY. 339 aggraded portion of the western slopes and on the plains adjoining the slopes. Mr. G. H. Halligan tells me that he has seen gilgai country well developed between the Kalga Range and Ooonamble (Urawilkie). The universal experience of scientific workers seems therefore to show that gilgai country occurs at the base of our western slopes in areas where aggradation has been great and often in places where indications of late tertiary subsidences are in evidence. It lies in the zone between the areas of denudation and the great Black Soil Plains and Red Soil Plains of the west. III. Characteristic Vegetation. The typical gilgai country of the Pilliga Scrub is covered witb dense brigalow and belar scrubs. The brigalow col- lected was identified for me by Mr. J. H. Maiden as Acacia harpophylla, and the belar as Casuarina lepidophloia. These two timbers seldom grow intermixed, but in some gilgai areas brigalow is wholly in possession, in others belar. Occasionally on the edges of gilgai country, as near Narrabri West, grey iranbark (Hucalyptus crebra) may be sparingly associated with the brigalow. Where such is the case the inequalities of the surface are only slight, amount- ing to two or three feet at the most. In other places the poplar box (EH. populifolia) is seen to extend some chains into the gilgai, especially where belar holds sway. Wilga (Geijera parvifiora) occurs sparingly in both belar and brigalow gilgais even in their centres, but especially where there is a tendency to the formation of red soil on the sur- face of the hummocks. On ‘ crabholey’ country near the edges of gilgai areas, and also on larger blocks of ‘crab- holey’ and ‘melonholey’ country, that is, less strongly developed gilgai than the deep gilgai, an oak (Casuarina glauca ?) and two phylloclade bushes (Leptomeria aphylla and Apophyllum anomalum) occur together with belar, wilga and brigalow. 340 H. I. JENSEN. The only herbs which seem to grow on typical gilgai country in the natural state are members of the saltbush tribe (Rhagodia species, R linifolia and others). The vegetation grows mainly on the hummocks sending long surface roots into the depressions. The gilgai vegeta- tion is characterised by abundant surface roots and an absence of tap root. | IV. The Soils of the Gilgai Areas. The soils of the gilgai country are mostly dark grey or almost black clays which in appearance suggest a consider- able degree of salinity. They resemble soils which have been irrigated with saline artesian water for a period of years. A small gilgai belt lying 10—12 miles south of Cuttabri, on the track to Cubbo, has red clay soil, and small patches of crabholey country also occur in the red soil belt along Baradine and Dubbo Creeks. In mechanical composition (See Table A) the gilgai soils are chiefly heavy stiff clays with a small percentage of rather coarse sand. In dry weather they crack with the formation of deep fissures just like the most heavy clay soils of the Namoi Black Soil Plain. In wet weather they are very boggy, and on drying they become as hard as cement. A crowbar or pick has to be used to get a soil sample. In the hummocks we find a layer of soil from six inches to two feet from the surface in which white specks and nodules, ranging up to the size of a pea, occur. These white lumps consist of carbonate of lime, chemically pre- cipitated. This precipitation of carbonate of lime in the subsoil of the hummocks indicates a rise of salts by capil- THE NATURE AND ORIGIN OF GILGAI COUNTRY. 34] larity from the hollows, and their precipitation by the evaporation of the water in a zone where the effects of dew and rainfall by downward percolation are negligible. The chemical nature of these soils is remarkable. They are alkaline in reaction on the hummocks, but the hollows may beacid. The gilgai soils proved on analysis (Table B.) to be far from well balanced, the amounts of phosphoric acid and sometimes potash being low in proportion to the lime (Table B). They are very high insoda and magnesia, and also in manganese oxide. The amount of soil insoluble in acid is lower than in the case of normal black soils. The water extract (Table C) contains in addition to colloidal clay a considerable amount of salts, chiefly sodium carbonate and common salt. Water-soluble magnesia and lime are practically absent in the hummock soils, being insoluble in alkaline solution. The sulphuric acid radicle is quite absent, no reaction for that ingredient being obtainable. The volatile matter in the gilgai soils ranges' from 4°50 to 9°86 per cent., averaging 6°42 per cent., but very little of this, probably not more than 3 per cent. is organic. The balance is combined water contained in the colloidal clay. Nitrogen is in most cases low, averaging °070 per cent. _ Occurrence of Manganese.—The manganese oxide {Mn,0O,) not carried down with iron, was estimated in the gilgai soils and is generally speaking high. Manganese being one of the most soluble constituents of acid soils tends to accumulate in undrained depressions. In the numerous complete analyses of soils given by Hilgaard in his book on the ‘Soil,’ the percentage of manganese seldom exceeds “020 in leached soils like the Hawaiian volcanic soils or those of the Californian orchard slopes; in other soils manganese ranges from °010 to ‘300 per cent. averaging “100, the humid soils giving a slightly higher average than 342 H. I. JENSEN. the arid ones. The reason for this is not clear, and the accumulation of further data may reverse the result. Our own experience in the Department of Agriculture of New South Wales is that leached laterite soils like those of The Dorrigo, the Robertson Range and the Macpherson Range, even when derived from highly manganiferous form- ations, are low in manganese and high in humus. Coastal marsh soils, highly acid peat soils, are quite free from manganese. Manganese is, on the other hand, high in soil from undrained depressions having a local catchment and no outlet except in flood time. In alkaline soils an accumulation of manganese might be expected when the alkalinity is due to carbonate of soda. This has been found to be the case, and is due to the fact that manganese enters largely into the composition of colloidal clay (see Hilgaard). The manganese estimated during the course of my work was only a portion of the total present, for the portion which was carried down with the iron was not separated and added on. The figures given therefore only repre- sent from one-half to at most two-thirds of the manganese present. Clearly these soils are high in manganese, a fact. suggesting that they have been accumulated in an un- drained basin. The salt and carbonate of soda present are evidences in the same direction. The remarkable thing is. that the faintly acid gilgai soils Nos. 5 and 15 are most. highly manganiferous, while the strongly alkaline soils Nos. 4 and 11 are least so. This paradox is rendered less startling when it is stated that the chemical work proved the alkalinity due mainly to carbonate of lime, the soda present being never a very excessive amount, though quite sufficient to be injurious. It appears then that while the lime which creeps into the hummocks by capillarity is precipitated there and : THE NATURE AND ORIGIN OF GILGAI COUNTRY. 343 accumulates in them, the manganese may creep up too, but is washed back to the depressions every time a spell of wet weather brings about a decay of leaves and a restor- ation of surface acidity. The manganese therefore tends to accumulate in the less alkaline depressions. The accu- mulation of manganese in these is evidence of absence of subdrainage, for if any escape existed the manganese would be carried away in the faintly acid soil water which May accumulate here. ) The capillary power of most of the gilgai soils is very poor, though the small patches of faintly acid red gilgai country may have very good capillary power. Small as the amount of sodium carbonate is in the alkaline soils it is yet sufficient to destroy their mechanical condition. The water capacity is highest in the case of the alkaline, colloidal clay soils. V. Origin of Gilgai Country. A number of theories have been advanced to explain the uneven nature of gilgai country. The most accredited are: 1. Collapse of substrata causing a breaking up and partial subsidence of the top soil. 2. Expansion and contraction due to alternate wetting and drying. 3. Removal of soluble soil ingredients, as for instance lime, by percolation into the underlying sandy, Subartesian strata. 4, Wind action. d. Effect of vegetation. 6. Effect of sodium carbonate in destroying soil crumbs, and causing partial collapse of the soil. 7. Mud springs. 1. The theory that the irregularites in surface are due to faulty substrata, or subsiding substrata, is widely 344 H. I. JENSEN. accepted by surveyors. Support is lent to this theory by the fact that gilgai country occurs only along the belt of heavy Tertiary and Post-Tertiary alluviation, at the western base of our western slopes. The deep detrital accumula- ions of this belt are no doubt settling down and being rendered more compact by their own weight. Buta sub- sidence due to this cause can hardly be expected to give rise to the vermiform depressions and tortuous hummocks observed in the gilgais. The whole surface would be expected to subside at a uniform rate, and if ridges were formed at all, one would expect them to have a definite alignment and to be of a gentle nature. It has been suggested that the depressions are due to an underlying limestone formation, which is being removed by subterranean waters and causing overlying soils to sink into the hollows so formed. This suggestion can be dis- missed with the statement that borings in the district show no limestone in the substrata but only sands and clays. Nor is there a scrap of geological evidence to favour the suggestion. It has also been suggested that subterranean streams in the underlying subartesian strata might be undermining the surface soil, bringing about its collapse. No such streams have been met with, nor could such a cause produce the tortuosity of the gilgais over such a wide area. 2. Alternate expansion and contraction of clay lands from wetting and drying is known to produce an uneven surface. The inequalities produced in this way seldom exceed six or twelve inches. On p. 114, ‘The Soil,’ by Hilgaard, such country is described under its American name ‘hogwallows.’ This cause by itself could not produce the gilgais, though it might give a start to the formation of a hummocky sur- face which might develop into gilgai from other causes. THE NATURE AND ORIGIN OF GILGAI COUNTRY. 345 The coefficient of expansion of gilgai soil on wetting is certainly great as illustrated by the experiment described in Appendix I. The crabholey and melonholey country of our tablelands and coastal regions is often formed in the same way as * hogwallows.’ = 3. The removal of soluble ingredients by downward filtra- tion cannot have produced the gilgais, for the soil is almost impervious, being exceedingly clayey, and if removal by downward percolation were the cause of gilgai formation the hollows should contain less manganese. Drained soils are usually low in manganese; gilgai soils are high in that constituent. There can be little or no downward drainage into subjacent water-bearing strata. The gilgai holes hold water for many months after rain and appear to lose it only by evaporation. 4. Great inequalities of surface are often caused in arid regions by wind action on loose detrital deposits. One might suppose the gilgai surface to have originated in a quaternary, very arid, cycle prior to any kind of vegetation getting a hold on it, by the wind scooping out the hollows. At the present time the country is too well wooded for the wind to have any such effect. But hummocks raised by the wind should have definite shape and alignment. Theirregularity of the gilgai surface cannot be explained on this hypothesis. 3. In swampy country of our coastal districts and table- lands and in lowlying country frequently flooded, we fre- quently find a tussocky grass or grasstree (Xanthorrea) grass growing in tufts. The roots of each tuft keep on raising the spot on which the tuft grows by their decay and intervening spaces between the tussocks are lowered by nutriment being drawn away fromthem. The tussocks 346 H. I. JENSEN. also tend to raise the spots on which they stand by catch- ing atmospheric dust and débris. In this way ‘melonhole’ country often forms in coastal districts. Its formation may be aided by the alternate expansion and contraction of the soil on wetting. Indeed coastal ‘melonhole’ country is usually on peaty clay soils and the knobs being more peaty than the hollows would probably expand at a more rapid rate and to a greater extent on ‘wetting.’ While such causes might have helped to produce the beginnings of gilgai country in the Pilliga Scrub, they are no longer operative, for the soils are not peaty in nature, nor do the roots of the plants existing there at present act as do the tussock grasses of swamps. The roots of belar and brigalow being mainly surface roots certainly help to maintain the hummocks intact, but I cannot believe that they have produced these irregu- larities. Indeed belar grows abundantly on country which is not ‘gilgai,’ and I believe this is the case with brigalow. also. 6. Mr. J. fF. Campbell, L.s., in a paper on Soil Physics read at a meeting of the Institute of Surveyors on May 18th 1909, suggested that ‘melonholes’ (‘crabholes’ or ‘small gilgais’) are due to the effect of sodium carbonate in destroying soil crumbs and causing the soil to subside by counteracting the cementing crumb-producing properties of carbonate of lime. | Possibly this cause may at times produce ‘melonhole’ country, but I cannot believe that our gilgai country could have been produced in this way. Chemical evidence is also against this theory, for in my soils the hummock soils had the highest alkalinity, whereas their alkalinity should be least under Mr. Campbell’s hypothesis. 7. Mudsprings exist according to the statements of many old pioneers of the Pilliga Scrub in the country lying about THE NATURE AND ORIGIN OF GILGAI COUNTRY. 347 15 to 20 miles south of Brigalow Creek on the back runs of old ‘OCubbo’ station. These mudsprings are described as mound springs. One is described as being situated in the centre of a round clay pan. The bushmen believe that these clay pans are often formed by the subsidence of country round the vent of a mudspring. Clay pans witha saline soil, studded with extinct mounds built up by mud- springs are reported as numerous in the comparatively unknown parts southward from Brigalow Creek. It has been suggested to me by local men that the gilgais are the result of mudspring action, but while I can readily under- stand that round mounds and circular depressions can be formed in this way, I fail to see how the labyrinthine courses of the gilgai contours can be formed in this way. Having now disposed of the various theories advanced by others, I desire, before advancing my own to discuss a question which bears considerably on the result. It is that of Late Tertiary Climate. VI. Late Tertiary Climate. In several papers’ I have given facts in evidence of remarkable changes of climate in our western districts in Late Tertiary and Quaternary times. It is generally agreed by geologists that in the late Tertiary periods large areas of Central Australia consisted of lakes receiving sediments from the high ranges that separated these parts from the coast. Central New South Wales and Queensland constituted a depression in which extensive alluviation took place. Mammalian drift occurs in places and gives evidence in favour of a moist, if not very wet, climate. The remark- able fauna of giant marsupials which existed up to the end 1 Prelim. Note on the Geol. History of the Warrumbungle Mountains, Proc. Linn. Soc. of N.S.W., May, 1906. Geology of the Warrumbungle Mountains, loc. cit., August, 1907. Geology of the Nandwar Mountains, loc. cit., 1907. p48 H. I, JENSEN. of the Tertiary period was decimated owing to the estab- lishment of desert conditions. Drainage became disin- tegrated. Arid erosion succeeded normal erosion. To the west of the Warrumbungle Mountains near Toora- weanah, at Coonamble, at Nyngan, and throughout the Pilliga Scrub I have obtained abundant evidence of a period not far removed from the present, in which drainage was completely disintegrated, and erosion was wholly of the arid type. The late Tertiary wet period leaves its insignia in the form of old water channels bestrewn with boulders so large that the floods of present streams are unable to account for anything like them in the same districts, and in the form of huge accumulations of sand and coarse gravel underneath the varied soils of the western plains. The dry cycle which followed levelled up the country, filling former creek beds with windblown drift, and arid erosion added to the accumulation of detritus at the base of the slopes. The present period can only be described as subarid. There is a sufficient rainfall to permit erosion to take place and the drainage systems have become re-integrated. Additional evidence of increased rainfall is afforded by the present creeks cutting V shaped valleys along their present courses through the heavy thicknesses of Tertiary and Quaternary drift, especially along their upper courses. Along their lower courses over the plain the tendency is largely to aggrade in flood time. In the Pilliga Scrub gilgai belt the two or three hundred feet of sand, gravel and clay under the surface soil, consist largely of detritus borne down from the Warrumbungle and and Nandewar Mountains in the wet period of the Tertiary. - During the succeeding dry climate the detrital deposits were added to and drainage became disintegrated by the THE NATURE AND ORIGIN OF GILGAI COUNTRY. 349 silting up of the outlets of numerous swamps and marshes along the courses of stream channels. Subsequently wind- action filled in these channels. In the Pilliga Scrub the gilgai area, originally a depression, which was during the wet cycle receiving Warrumbungle detritus carried down by large rushing streams, became a sea without outlet, and later, as the streams became extinct, a series of salty marshes into which little trickles of water, highly charged with solids, came from a great abundance of mudsprings in the back country. The dark (black and dark grey) gilgai soils were laid downatthistime. Their peculiar chemical and mechanical nature shows that they are not true alluvial soils like those of the Black Soil plain. Their high lime and magnesia, without correspondingly high potash and phosphoric acid, suggest that they were derived from the evaporation of spring waters. Their salt and soda contents show accu- mulation in an undrained basin, and this conclusion is strengthened by the high manganese. Mudsprings might have existed locally over the gilgai area, but probably the muds were chiefly supplied by springs some little distance away on the flanks of the Coghill hills in the centre of the Pilliga Scrub. In these saline marshes various coarse grasses would grow in tufts and give rise to inequalities of surface, which would be increased by, (1) the greater shrinkage and crack- ing on drying of the intervals between the tufts than of the knolls which the roots would tend to hold together, and by (2) the chemical deposition of carbonate of lime round the grass roots and stems on every occasion that a particularly droughty spell caused the evaporation of a marsh. This kind of precipitation of lime we often see where sea-water has been carried by spring tides into the small swampy depressions behind the hurricane bank of the 350 H. I. JENSEN. shore and undergoes quiet evaporation. In this way the knolls would grow in size especially as the fine matter carried down by the small streams would tend to deposit both its dissolved and suspended material chiefly on the tussocks. One can state with absolute certainty that the gilgai soils were not deposited by normal streams from the War- rumbungles either in the late Tertiary wet period or in the present semiarid period. Both the floods of the former and of the latter are chiefly responsible for sandy material such as we see along present creek beds or in the alluvial strata underlying the gilgai at a depth of 30 to 40 feet. While I cannot agree that the hummocky surface of gilgai country is due to subsidence of underlying strata, I am strongly inclined to think that the formation of large basins which developed into gilgai areas was partly due to sub- sidence of late Tertiary sands and gravels ofa loose nature which havea great thickness under these areas. It is true that these depressions always occupy sites along a belt of our western slopes which is largely downfaulted, but the faulting was probably in progress in the wet cycle of our late Tertiary period and responsible for the thick accu- mulation of detritus deposited along this belt at that time. - The amount of subsidence in the arid period was probably very slight, so slight that it can easily be accounted for by the settling down of loose sediments. OTHER HVIDENCES. (a) West of the Warrumbungles.—On the plain country westward from Tooraweanah and Tundebrine, on the western side of the Warrumbungle Mountains, it is a com- mon thing to find the present creeks separated by slight ridges, each of which is capped by an old creek bed con- sisting of boulders and heavy gravel. Almost invariably — the highest ground is a gravel ridge marking the course of THE NATURE AND ORIGIN OF GILGAI COUNTRY. 351 a former stream. These ridges are usually only from 10 to 15 feet higher at the most than the intermediate gullies, The present streams in this vicinity are denuding the country, otherwise they would not occupy depressions, but the water would come down in a sheet from the mountains, and the old creek gravels as wellas the intervening country would be covered with a uniform level sheet of recent silt. In very recent geological times (Quaternary) there was an arid period in which the ancient creeks ceased to run, when débris accumulated in the mountain valleys of the Warrum- bungles mainly through arid erosion, when the small spring fed creeks flowed only to the edge of the mountains and became absorbed in the thirsty soil while they deposited their fine silt in the form of small black soil plains. In this period the country immediately north and west of the mountains became a plain, levelled by arid agencies. When again a moister climate came, the streams, though large enough to cut down, were not large enough to remove the boulder beds of the old stream channels, hence we find present streams carving down in the old alluvial plain formed by the floods of the wet cycle leaving the old chan- nels as intervening ridges. This I take as clear evidence of a more arid climate than the present in recent geological time. (b) North of the Warrumbungles.—To the north of the Warrumbungles on the drainage areas of Cubbo Creek, Dubbo Creek, and Baradine Creek, similar facts are in evidence. Great alluviation took place in the wet cycle, the streams depositing most of their sand and gravel as soon as they reached the level country. A dry period followed in which all inequalities were levelled by wind action, the courses of old streams becoming infilled with drift sand. Many of these former courses are easily picked out by their more sandy soil and by gum and apple trees 352 H. I. JENSEN. mingling with pine along them instead of the usual associ- ation of pine and box. That this arid period has come to a close is evidenced by the deep U-shaped depressions or gullies cut by the present creeks from the Warrumbungles in the deep late Tertiary alluvial. Thus at Baradine, the creek is a deep gully 40 feet below the surrounding level country. The banks of the creek rise steeply, indicating that this gully has been carved and is being enlarged by each successive flood. The same is the case with Bohena or Borah Creek and other creeks until they get 20 or 30 miles away from the mountains. Along their lower courses in the plain country these creeks still occupy depressions, more shallow courses carved by the rare and occasional big floods, and filled up again with sand by smaller floods. The smaller creeks in this plain country do not actually occupy depressions. Their beds are lower than their banks but about the same level as the country passed over. The banks are built up of sand washed down from the hills; is the product of the period of arid erosion redistributed by water in the present cycle. This is the case in the gilgai belt where small creeks like Oakey Hole Creek and Brigalow Creek are entrenched between banks of their own flood products. The fact that streams carrying down sheets of sand have been able to sweep over the gilgai plain indicates a restoration of integrated drainage by the advent of moister conditions. (c) The Castlereagh and Coonamble Plains.—At Ooo- namble and on the surrounding plains we also get abundant evidence of an arid period having existed prior to the present period. The deep alluvial soils are underlain by great thicknesses of sandy drift and clays deposited over the Coonamble district area in the wet periods of Tertiary time. The lake or swamp in which this alluviation took place dried up on the inauguration of arid conditiens, but é THE NATURE AND ORIGIN OF GILGAI COUNTRY. 353 when occasional heavy downpours occurred in the Warrum- bungles water would come down in a sheet, carrying with it the fine silt now forming the Black Soil Plain. After a . period of great aridity, in which wind blown detritus only accumulated, moister conditions again allowed flood waters to come down from the mountains. The larger floods carved shallow beds in the level country. These were promptly infilled with sand by smaller floods, while the finer silts settled on the flooded plains adding tothe black soil deposits. The old stream beds formed in this way are known as ‘monkeys.’ Thecountry being very level, the rivers would continually change their courses as it was easier for fresh floods to sweep across the black soil than to sweep over the old sand beds which were often higher than the intervening country, owing to the greater subsidence on drying of mud than ofsand. The continual change of course by the Castlereagh River in the early part of the present cycle was probably aided by the fact that the drainage System had not yet become reintegrated. Occasionally the flood waters would sweep westwards from Coonamble and empty into the Macquarie marshes. At other times they would sweep north-west into marshy country near the present junction of the Castlereagh with the Barwon. That conditions are moister now is shown by the fact that the present bed of the Castlereagh is a definite U- shaped hollow containing little or no sand. The Gwydir and Moree Plains.—Similar observations were made on the Gwydir River near Moree. The Bogan and Bogan Plains.—At Nyngan ona visit about two years ago, I noticed similar evidence of a recent arid period. The red soil plains on the western side of the Bogan are fine grained windblown soils derived from the Cobar massive of metamorphic rocks. The black or rather brown soils on the eastern side of the Bogan consist of a W—Dec. 6, 1911. 354 H. I. JENSEN. mixture of windblown detritus and silt deposited in a kind of marsh by floods from the Central Tableland in the period of increasing rainfall before integrated drainage was re-established. Evidence ofa greater rainfall at the present time is afforded here by two facts, (1) a slight amount of undulation has been produced in the windblown detritus by rainwaters in the present cycle, (2) the Bogan River flows in aslight depression and reaches the Darling in flood time so that the drainage has become integrated. Under both the red and black soils of the Bogan we get hundreds of feet (from 300 to 1500 feet) of Tertiary gravels and clays which were deposited under wet meteorological conditions, possibly ina lake. The coarseness of the sands and gravels interbedded in this series shows that big streams deposited here the material carried from the central parts of the Cobar massive. The great differences in depth to bed rock in the various bore holes around Nyngan show that the depression in which this heavy alluviation took place was probably formed by downfaulting in a period when the Cobar massive was a rugged mountain group widely different from the smooth and weatherworn aspect it presents at the present time. In fact mesas of Triassic rock occur under the Bogan silts, though to-day no Triassic (Trias Jura) rocks remain on the Cobar massive, proving that a block of country around Nyngan was depressed or downfaulted in early Tertiary period. Two points of interest might here be briefly touched on. Firstly—The difference in climatic conditions between the period of aridity and the present is not great, and it might be held that the restoration of integrated drainage is the effect of an uplift of the Central Plains rather than of increased rainfall. Whether this is the case or not I cannot say, but I think that recent conditions are less arid than those of the period of disintegrated drainage. THE NATURE AND ORIGIN OF GILGAI COUNTRY. 30D Secondly—There appears to be good reasons for believing that in quaternary times a number of semiarid periods and arid periods have alternated, just as did the glacial and inter-glacial periods of the last Ice Age. For some of the red clay bands in the upper clay bands interbedded with the late Tertiary alluvials and drifts underlying the plains might well be wind blown deposits of arid intervals between the wet periods which gave us the gravels. Again the numerous ‘monkeys’ of the Castlereagh and other rivers may each have had its course formed in a wet period, and might have been filled with drift sand in the succeeding dry period. This too is a plausible theory. VII. Origin of Gilgais. It is possible that a tussocky herbaceous growth has been aided by the contraction and expansion of clay soils with wetting and drying, and by the chemical precipitation of lime and magnesian salts on plant roots during periods of drying up in the formation of a hummocky surface over the gilgai area of the Pilliga Scrub. The question arises, if such an origin be assumed, why did the inequalities not vanish when marshy conditions disappeared with the restoration of integrated drainage ? Not only have the hummocks remained, but they have become enlarged and the depressions have relatively deepened. There can be little doubt that the salinity of the Pilliga Scrub gilgais has been reduced by repeated floods inthe recent period. There can be little doubt that the present flora of belar, brigalow and saltbush took root as soon as moister conditions commenced and that these plants have helped to preserve the hummocks and to resist their collapse. But the vegetation could not have performed this work without the assistance of another factor which has done much to produce an accentuation of the hummocky surface. This factor is the migration of salts and carbonates of lime and magnesia into the hummocks by capillarity. Ohemical analysis shows the hummocks to contain a higher percen- tage of these substances than the depressions. So great. has the precipitation of lime been in the hummocks, that at a depth of six inches it forms little pea-shaped nodules. or concretions in the soil. Unquestionably the forces of capillarity have in the present cycle done much to enlarge the hummocks. Inequalities of surface must have pre- existed and might have been produced by one or all of the suggested causes, but the main features of gilgai country as distinct from ° melon-hole’ country is the augmentation of existing inequalities of surface by capillary action. 356 H. I. JENSEN. Mudsprings.—Some mudsprings are supposed to be still active in remote portions of the Pilliga Scrub. Many extinct ones occur, as well as salt pans formed by mud- springs. These occupy a line along the border between the flat alluvial belt of the north-western plains and the outermost outcrops of Trias Jura formation. Not having seen these mudsprings it is not possible to say anything with confidence about them. Yet their presence along the border between the belt of heavy Tertiary alluviation and the Trias Jura suggests that they might have been produced by the expulsion of enclosed water from the loosely cemented Tertiary débris by the settling down of this material under its own weight. The Tertiary gravels of the Pilliga Scrub are very water bearing, though only pumping supplies are obtained in the bores. The bearing of the here suggested origin of the mudsprings. has an important bearing on the origin of artesian water. The matter is of economic interest and wants further investigation. VIII. Summary. 7 In this paper I have given a description of gilgai country, some remarks on the distribution of such lands, and possible THE NATURE AND ORIGIN OF GILGAI COUNTRY. Bail mode of origin. It is suggested that in the gilgai zone of the Pilliga Scrub this type of country was a lake without outlet at no distant geological period. In this period the rainfall of our north-western districts was exceeding low, and the gilgai lake was dry at intervals, receiving only small streams from mudsprings in the hilly country twenty miles away. The contraction of the clay deposits on Meine. the growth of tufty grasses in the salt marshes and chemical precipitation on the tussocks gave rise to a hummocky surface. When moister conditions revived the creeks from the Warrumbungle Mountains integrated drainage was restored. The inequalities of surface on the gilgai area were accentuated by capillarity when new conditions had been established. | Various facts of physiographic interest pointing to grave Climatic changes in recent and late Tertiary times are recorded in this paper. ANALYSIS OF GILGAI SOILS. Table A.—WMechanical Analyses. No. | Colour. Reaction. eee Ticheainth cee CHDyE | Ieuies | eh Per cent. hours. Per cent. | Per cent. | Per cent. 4 | black | strongly alkaline} good 49 fair 3 10'2 | 18:3 | 71°5 5 3 faintly acid fair 44 fair 4 74 | 10°7 | 81:4 6| ,, | alkaline good 47 fair 3 10°'7 | 19°3 | 70:0 9 » | alkaline good 47 fair 44 | 10°0 | 22°3 | 66°9 11 » | Strongly alkaline} high 63 poor 2 2°4 1:0 | 96°6 15 | red | very faintly acid | low 33] excellent 10| 16°4 | 31°7 | 51:9 Table B.—Chemical Analyses. ° ngane No Moisture.| Volatile. | Nitrogen. Tea Fete pices an ede 7 N. 2 P30; Mn,0, Per cent.| Per cent. | Per cent. Eee cent. | Per cent.| Per cent. Per cent. 4 6°52 6°67 "042 1-080 "215 "152 “085 5 6°58 9°86 "142 "4.4.6 "225 "188 "155 6 7°55 7°27 070 ‘600 °335 °128 "100 9 3°50 4°50 04.2 *308 087 "049 "120 11 6°29 521 014 “712 "126 ‘079 "062 15 1:94 501 LZ ‘260 175 "1138 °270 358 H. I, JENSEN. Table C.— Water Soluble. Total Solids ake Total Solids : Sulphurie N including ea rey without us cid % \colloidal clay 2¥"'3 |colloidal clay H,SO, Per cent. Per cent. Per cent. Per cent. Per cent. Per cent. 4, "154 023 "069 ro trace absent 5 °106 012 "005 eas “4 et: 6 °100 "041 ‘010 an is | fs 9 n.d. * 006 trace ‘058 = ee ll "863 ‘058 °040 "1038 pe 5 15 he aos Ate AS. a0 | Br No. 4 = Belar gilgai hummock, Yarrie Lake. No.5 = Belar gilgai hollow, Yarrie Lake. No.6 = Cleared belar gilgai, Yarrie Lake. No. 9 = Belar gilgai, Alexander’s, Yarrie Leke. No. 11 = Brigalow gilgai, Trindall’s, Brigalow Creek. No. 15 = Red gilgai belt, brigalow and wilga, Cubbo-Cuttabri track. APPENDIX I. Two open cylinders, A and B, each 12 inches in diameter, were closed at one end with a piece of muslin, and were filled with coarsely powdered soil to a depth of 5$ inches. and 5; inches respectively. In A was placed gilgai soil (No. 11), in B black soil of alluvial origin (Namoi alluvial). Hach cylinder was thoroughly drenched with water until the soil in it was saturated. The soil in A expanded to 6% fnches and then became puddled, that in B expanded to 5% inches. The soil was. then allowed to drain, thereafter it was dried at 100° C., removed from the cylinders, broken up to the same degree of fineness as before, and then replaced in the cylinders. and measured. The soil in A had shrunk to 5 inches and that in B to 54 inches. The difference in volume between the saturated soil and the same dried at 100° O. was then calculated. The result obtained gave an expansion on wetting of 37°3% for the gilgai soil and an expansion of 17°1% for normal Namoi. alluvial. The expansion of gilgai soil on wetting is there- fore more than twice as great as that of black alluvial soil. SOME CURIOUS STONES USED BY THE AUSTRALIAN ABORIGINES, 359 SoME CURIOUS STONES USED By THE ABORIGINKES. By R. H. MATHEWS, L.s. [With Plate XV.] [Read before the Royal Society of N. S. Wales, December 6, 1911.] In the report of the Australasian Association for the Advancement of Science, Vol. x11, pp. 495 — 498, I described some remarkable stones, chipped and ground into shape by the aborigines, discovered over a large area of the north- western part of New South Wales, but which have not been reported from any other part of Australia. The scattered remnants of the tribes in the region indicated are all more or less civilized at the present time, and have ceased to use these stones in their ceremonies. For this reason it is especially important that all available inform- ation should be collected and published as widely as possible, in order to bring these relics under the notice of every person who may have opportunities of obtaining further particulars regarding this interesting subject. These prepared stones vary in length from less than half a foot to more than two feet, in exceptional cases, but the more common lengths range from 9 to 15 inches. They are of different material, including sandstone, clayslate, kaolin, quartzite and such other kinds of stone as might be available. In the majority of specimens the longitudinal axis is practically straight, as in Nos. 1, 2, 8, of Fig. 1. There are others which have a crescent or horn shaped shaft, of which No.3isanexample. The shaft is generally round in section, but examples are not infrequent where the breadth of the stone is two or three times greater than the thickness. Some are long and slender, as Nos. 2 and 8, whilst others are short and squat like Nos. 4 and 9. > i our 3 ’ 360 R. H. MATHEWS. They are thickest at the base and taper gradually upwards to an obtusely pointed apex. Some of them have a large Scale of Inches 0.1 2 3.4.5. 6. -7esaeee fn ai tu ef — fel — feet let] A HM, del Fig. 1—Seven Magical Stones. SOME CURIOUS STONES USED BY THE AUSTRALIAN ABORIGINES. 36] number of marks cut into the surface, apparently with a sharp stone, shell, or piece of bone, as Nos. 8 and 9; others have but afew incisions, whilst some are quite plain. A characteristic of this type of native implement consists of a depression worked into the base; in nearly all the specimens, instead of the large end being flat, the central part has been picked out and afterwards ground fairly smooth, forming a concavity resembling a shallow saucer or trough—the shape of the concavity depending upon whether the base is round, or is longer in one direction than in the other. In some specimens, instead of a single hollow, there are two trough-shaped depressions, as in No. 6, and specimens with three troughs in the base are occasionally found. Ina few examples, the base is flat or nearly so, witha number of grooved lines.reaching right across the diameter; or else starting at the centre and radiating in every direction to the margin. There may be only a few of these lines or there may be a score or more on the:base. It has been supposed that some of the softer specimens of these articles, kaolin for example, are not natural stones but have been artificially manufactured from burnt gypsum by the natives. Mr. R. Hall, curator of the Tasmanian Museum, speaking of a specimen in the museum, says in a letter to me:—‘‘According to Dr. Noething here, it (the specimen) is sulphate of lime, roasted and then wetted to form the required shape. That is also my opinion.’”’ Iam quite certain that none of the numerous specimens which I have met with have been made in that way, but that all of them, whether kaolin or not, are natural products cut into their present shape by human labour. No. 1. A decomposed sandstone, 244 inches long, with a circumference of 11 inches round the thickest part of the shaft. There are no marks on the surface, nor has it the 302 R. H. MATHEWS. usual depression in the base. It was found on Murtie Run, Darling River, and weighs a little over 10 Ibs. No. 2. A slender, cylindrical clay slate, 213 inches long, with amaximum circumference of 62 inches. Ata distance of 2+ inches from the apex, a well defined groove extends completely round the shaft. There is a slight depression in the base, and a number of marks all along the shaft, but not shown in the drawing. It was found near Wilcannia. No. 3, acompact grained kaolin, is interesting on account of its very pronounced crescent shape, on the convex side especially. The native workman had perhaps to accom- modate the design of the implement. to the form of the. block from which he obtained it, or the shape may have — been intentional. The total length is 12 and 33 of an inch. A section through the shaft about midway would have an elliptical shape, the longer diameter of which would be 34 inches and the shorter 2 7 inches. There are several marks cut into the surface, one of which, near the base, reaches quite round the stone, and there is a well defined hollow an eighth of an inch deep in the base or large end. The specimen was found on the Darling River above Wilcannia, and weighs 3 ths. 13 ozs. Nos. 4, 5, 6. A quartzite pebble, 9 inches long and 37 broad. No.5 isa side view showing the thickness of the : stone to be 2 3% inches. The specimen is evidently just in the condition it was in when picked up by the native artist, with the exception that the basal end was first beaten flat, and then a couple of trough shaped hollows worked into it. No. 6 exhibits the outline of these hollows which lie in the. direction of the longer diameter of the base. One of the hollows has been ground into a depth of a thirtieth of an inch, and the other is slightly shallower. This specimen is interesting from the fact that the only labour bestowed upon it consists of the formation of the cavities in the SOME CURIOUS STONES USED BY THE AUSTRALIAN ABORIGINES, 363 base. Mereover, two concavities in the base are of unusual occurrence, a single depression being the normal condition. The stone was found on Wilcannia Common, and weighs 4 ths. 3 ozs., which is a great weight for its bulk. No. 7, a whitish argillaceous sandstone, 45 inches long and 4 inches in circumference at the larger end. It is uninscribed and is without the characteristic hollow in the base. Found on Murtie Run, Darling River, and weighs 8 ounces. No. 8 represents a conical shaft of hard clay-slate, 11 inches long by a maximum diameter of 23% inches. A section through the shaft at right angles to the longitudinal axis would be almost circular. An oval shaped concavity has been ground into the base to a depth of 3% of an inch in the deepest part. The weight of the implement is 2 tbs. 7 ozs. On the side represented in the illustration there are 99 incised marks, many of which are horizontal or nearly so, and are in pairs. About an inch from the pointed end, one of the lines is cut completely round the stone. Attention is also invited to 14 pairs of short, almost vertical incisions, a form of marking which is somewhat uncommon. The regular and symmetrical outline of this specimen, as well as the extensive marking, show that considerable labour has been expended upon it. Found on Tankarooka Run. No. 9. This profusely incised specimen is a reddish coloured rock, probably derived from basalt, rich in iron, and may be described as a sandy laterite. A small portion has been broken off the base and also off the apex, the supposed extent of the missing parts being indicated by dotted lines. The present length of the stone is 95 inches, but was probably about 102 inches originally. The circum- ference round the thickest part is 11 inches, and a section through the stone at that place would give an elliptical 364 R. H. MATHEWS. figure, with a longer diameter of 4 inches and a shorter of 2; inches. There are numerous horizontal lines of excep- tional length, as well as some vertical and oblique ones, cut conspicuously into the surface; the total number being 111. All the markings are straight or nearly so, with the exception of two near the middle of the specimen, which have a graceful curve. Found near the southern end of Poopelloe Lake, and about 20 miles south from the Darling River, and weighs 4 Ibs. 2 ozs. The uses of the stones above described are not fully known, but sufficient evidence has been gathered by me to show that they were employed in magical incantations connected with causing the food supply to increase, making rain, injuring an enemy, and other occult functions. The object of the present article is to promote and encourage inquiry by station owners, managers, and others residing in the north-western districts of New South Wales, where there are still a few old aborigines who could perhaps increase our knowledge respecting these curious native productions. For the purpose of enabling the reader to obtain a more realistic conception of what the stones look like, I have added a photograph of six specimens (Plate XV, Fig. 2). The crescent or horn shaped stone, No. 5 in the photograph is identical with No. 3 in the diagrammatic drawing. Another stone, No. 1, also has a crescent form outline, especially on one side. In all of the specimens the shaft is practically round and would give an almost circular section. The material in these specimens is kaolin, sandstone and clay- slate, and each of them has a shallow hollow in the base. The six specimens in the photograph are different from those shown in the diagrammatic drawing, with the excep- tion of No. 5 as stated above. On the floor of the photo- graph are six stone hatchets of different sizes, three of AUSTRALIAN MELALEUCAS AND THEIR ESSENTIAL OILS. 365 which havea very distinct deep groove around them, for the purpose of attaching the handle. They are not numbered. Another photograph (Plate XV, Fig. 3), shows six magical stones, all of which are different from those described, excepting No. 3, which is the same stone depicted as No. 9 in Fig.1. Nos. 1, 2, 3, and 4, are of the same material as No.9in Fig.1. Nos.8and 10 are clay-slate, while the rest. are grey sandstone. The three small articles on the floor of the picture are stone hatchets used by the aborigines, and are without numbers. ON THE AUSTRALIAN MELALEHUCAS AND THEIR. ; ESSENTIAL OILS, Part IV. By RIcHARD T. BAKER, F.L.S. and HENRY G. SMITH, F.C.S.,. Technological Museum, Sydney. With Plates XVI - XXIV. [Read before the Royal Society of N. S. Wales, December 6, 1911. | Melaleuca genistifolia, Sm. Historical.—_This species was described as far back as. 1796, by Dr. Smith, in Trans. Linn. Soc., London, III, 277. Bentham in his Flora Australiensis, Vol. III, p. 144, (1843, 1858) synonymises M. lanceolata, Otto. and M. bracteata, F.v.M. under it. In our third paper on the Melaleucas published in this. Journal, Vol. XLIV, it is shown both botanically and chemically that M. bracteata is quite distinct from M. genistifolia, and further it will be demonstrated in a later paper that M. lanceolata is all that is claimed for it as a species. 366 R. T. BAKER AND HENRY G. SMITH. Remarks.—As Bentham’s description, loc. cit., may now be regarded as a composite one, and Smith’s a little too brief perhaps to mark clearly the tree indicated, a descrip- tion is added (infra) in order to definitely place the species, and to show upon what material the histological and chemical work is based. Smith after his short description in Latin loc. cit., states inter alia :—‘“It is in some respects like M.nodosa.’’ This evidently refers to the infioresence, which in some instances is rather in a close cluster than a spike. Mr. CO. F. Laseron in his field notes states that at Gosford it isa small very crooked tree rather straggling in growth, growing in flat localities among other “‘tea trees.’’ Diameter very rarely above 5 or 6’, timber reddish. Description of Plant.—A shrub attaining 30 feet in height with a thick papery bark. Leaves ovate, blunt or obtuse, slightly concave, trinerved, shortly petiolate, about — 3 lines long and 13 lines wide. Flowers in short terminal spikes or clusters. Calyx pubescent. Fruit sessile, cup or urn Shaped, constricted below the rim, which is some- times contracted, valves not exserted. Leaf Histology.—The leaf being slightly concave, a cross section is boomerang in shape. The structure is uniform, the two parenchymas being in equal proportion. The palisade layers are of equal thickness on both sides with rather more delicate cell walls than generally obtains in the Melaleucas examined by us. The spongy parenchyma cells are circular in cross section, through the middle of which run the vascular bundles, three in this case being most prominent, these give the trinerved feature men- tioned by Smith when first describing the species. The main bundle is normally orientated, the phloem being towards the under side. A circle of sclerenchymatous fibres more numerous on the outer sides surrounds it (and similar AUSTRALIAN MELALEUCAS AND THEIR ESSENTIAL OILS. 367 tissues of the other two) but occasionally a few parenchyma cells extend around it to the cuticle. The epidermal cells are small and irregularly rectangular in shape. The lysigenous oil glands are few and scattered throughout the leaf tissue. Some sections show the presence of the man- ganese compound in the cells. Essential Oil.—The results obtained with the oil of this species again illustrate the fact brought forward in our last Melaleuca paper (Part III of this series), that the chemical characters of ordinary ‘*Cajuput’’ oil are not representative of the group of essential oils obtainable from the Melaleucas. The constituents of the oil of each species appear to be representative and characteristic for that species wherever found growing naturally. Since our last paper we have obtained material of M. bracteata from Kinbombi in Queensland, hundreds of miles from the pre- vious locality, and the’oil distilled at the Museum from that material was identical in character with that described for this species (Proc. this Society, Dec. 1910). The oil of M. genistifolia was distilled in Victoria in 1862 by Mr. Bosisto, but he only obtained 0°07 per cent. of oil from the leaves and branchlets, and no data are given as to the character of the oil. Our results as to yield do not agree with the above, as we obtained over half per cent. of oil from our material, which also consisted of the leaves and terminal branchlets like that which would be used commercially. The oil of M. genistifolia consists very largely of dextro- rotatory pinene—which has a very high rotation—and is almost devoid of cineol, less than 2 per cent. of that con- stituent being present in the crude oil. As the oil contains between 80 and 90 per cent. of pinene, it might have some economic value as a “‘turpentine’’ producing plant, pro- viding the vield of oil was greater than it is. a ae . ol . 1@ 368 R. T. BAKER AND HENRY G. SMITH. Experimental.—The material was collected at Gosford in this State, and distilled in January, 1911. The amount of material was 214 ibs., and the oil obtained was 18 ounces, equal to 0°526 per cent. The crude oil was reddish brown in colour, due to the small quantity of iron present, but it was readily cleared to a light yellowish colour when agitated with two or three drops of phosphoric acid, well washed and dried. It had a marked turpentine odour, and cineol could hardly be detected in it. The crude oil had the following characteristics :— Specific gravity at 15° C. oe . = 0 80e Optical rotation ap... i 0 = spreeame Refractive index at 22° C. 1°4702. Cineol (determined by the resorcinol method in the second fraction) ... = 2 per cent. Saponification number of ester + free acid = 6°8, Insoluble in 10 volumes 80 per cent. alcohol. I For distillation, 100 cc. were taken. The amount of acid water and volatile aldehydes distilling below 155° C. (cor.) was very small indeed. Between 155 — 162° 79 cc. distilled; between 162—183° 6 cc. The thermometer then quickly rose to 250° and between that temperature and 263° 11 ce. came over. The specific gravity of the first fraction at 15° O. = 0°8661; of the second = 0°881; of the third = 0°9293. The rotation of the first fraction ay = + 36°8°; of the second = + 19°6°. The refractive index of the first fraction at 22° O. = 1°4645; of the second = 1°4671; of the third = 1°4967. : Another distillation was undertaken with comparable : results. The first two fractions (145 cc.) were then added together and again distilled, when between 154-156 C. 114 cc. distilled, and between 156 -— 158° 13 cc. more. The quantity of oil boiling within two degrees of temperature from AUSTRALIAN MELALEUCAS AND THEIR ESSENTIAL OILS. 369 200 cc. was 114 cc., = 57 per cent. The specific gravity of the first fraction at 15° O. = 0°8638; of the second = 0°8667. The rotation of the first fraction dp = + 39°1’, or a Specific rotation |a], = + 45°27", of the second fraction = + 36°3°, or a specific rotation [a], = + 41°88°. The refractive index of the first fraction at 23° C. = 1°4636; of the second fraction = 1°4638. The nitrosochloride was readily prepared with the oil of the first fraction; it was purified by dissolving in chloroform and precipitating with methyl alcohol. It melted at 104° ©. (uncorr.). The higher boiling constituents of this oil consisted largely of the sesquiterpene, and gave the characteristic colour reactions for that substance. It also contained some ester, the saponification number being 16°7, equal to 5°8 per cent. of ester calculated as terpinyl-acetate. Melaleuca gibbosa, Labill. Historical.—This species was first described by Labil- lardiére, Pl. New Holland 1799, presumably from a Tasmanian specimen, and has since been recorded from the mainland in Victoria and South Australia. Remarks.—It stands in the happy position of having no synonyms, so that after these years its systematic status must be regarded as unchallengeable. The fruits perhaps call for a little notice, for as soon as maturity is reached they are then a little distance from each other, but gradu- ally become immersed in woody tissue by a thickening of the rhachis. Although it appears to be a constant feature of the species, yet it may be pathological and is worthy of investigation, for perhaps here we may havea host species of either the animal or vegetable kingdom. Weare indebted to Mr. EK. Rodway, F.L.s., Government Botanist of Tasmania for fresh material for dissecting purposes. X—Dec. 6, 1911. 370 R. T. BAKER AND HENRY G. SMITH. Leaf Histology.—Amongst Melaleucas there are several differences which characterise the structure of the leaf texture of this species. The palisade parenchyma is not a distinct feature in a cross section, although it is more in evidence on the underside of the leaf than towards the top surface. The cells of the spongy parenchyma have circular walls in a transverse section, as against the angular shape of those of M. leweadendron, and this particular leaf sub- stance is in greater proportion towards the petiole, although in other parts of the leaf it is in equal proportion to the palisade parenchyma. Near or close to the petiole, the palisade parenchyma gives place entirely to spongy paren- chyma. Stomata occur mostly in the lower portion of the leaf and more especially on the inner or upper surface at that portion of the blade. Another distinguishing feature in this part is the strong development of papillose projec- tions on the cuticle of the epidermal cells of that surface. The vascular bundles are normally orientated, the phloem facing the outer or under surface of the leaves, and are entirely surrounded by a compact or coalesced body of sclerenchymatous tissue exceeding in area that of the bundle. These were doubtiully regarded as transfusion tissue under M. uncinata, Part I of thisseries. The median bundle is finally bounded towards the cuticle by spongy mesophyll which thus makes a complete break in the con- tinuity of the palisade parenchyma. Essential Oil.—The oil of this species consists largely of dextro-rotatory pinene, cineol, a small quantity of ester, and a sesquiterpene. It belongs to the pinene-cineol group of Melaleuca oils, and resembles somewhat in general characters the oil of M. nodosa, although it is richer in cineol than the oil of that species. The yield of oil is some- what small, so that M. gibbosa cannot be considered of value as an oil producing tree. | . : . AUSTRALIAN MELALEUCAS AND. THEIR ESSENTIAL OILS. HA Experimental.—The material was collected at Little Swanport, on the east coast of Tasmania, and distilled in June, 1908. The leaves and terminal branchlets were alone used, and 316 ibs. of material gave 8 ounces of oil, equal to 0°158 per cent. The crude oil was of a dark lemon yellow colour, and had an odour resembling the cineol- pinene oils of the Melaleucas, as for instance that of M. thymifolia. The crude oil had the following characters :— Specific gravity at 15° O. Be Pe ae OL Or Optical rotation ad) ... ee Bae eee Refractive index at 20°C. ... um pisse 408. Cineol (determined by the resorcinol method) = 61°57 Saponification number of ester + free acid = 9°9. Insoluble in 10 vols. 70 per cent., but soluble in 1 vol. 80 per cent. alcohol. This comparative insolubility is evidently due to the presence of the pinene and the sesquiterpene. For distillation 100 cc. were taken. The usual small amount of acid water, and volatile aldehydes, were first obtained, and these reminded strongly of valeric aldehyde. Between 165—173° (corr.) 28 cc. distilled, and between 173—195° 52 cc. came over. The thermometer then quickly rose to 245° and between that temperature and 265° 16 cc. distilled. The specific gravity of the first fraction at 15°C. = 0°8963; of the second = 0°9045; of the third = 0°9252. The rotation of the first fraction dy = + 6°8°, of the second = + 3°9°. The refractive index of the first fraction at 20° C. = 1°4621; of the second = 1°4630; of the third = 1°4954. The cineol in the first fraction was removed by resorcinol, the residue again rectified, and the portion distilling below 158° C. utilised for the preparation of the nitrosochloride. This substance was readily formed; it was purified by dissolving in chloroform and precipitating with methyl alcohol. It melted at 104°C. The active o12 R. T. BAKER AND HENRY G. SMITH. terpene in the oil of this species is therefore dextro- rotatory pinene, and the limonenes appear to be absent. The high boiling fraction consisted largely of the sesqui- terpene, which is so pronounced a constituent in the oil of M. paucifiora, and the characteristic colour reactions were readily obtained with it. It also contained a fair quantity of ester, the saponification number being 20°7. The odour of the separated oil, after saponification, reminded of ter- pineol, and the acid was determined as acetic, so that the ester is probably terpinyl-acetate, and the fraction thus contained 7°24 per cent. of that substance. Melaleuca pauciflora, Turcz. Historical.—This species was described by Turczaninoff in Bull. Mosc. in 1847, and so far its systematic position or rank has not been challenged, nor has it any appendages in the form of synonyms. | Remarks.—This Melaleuca is characterised by leaf features found to occur only in one other species of the genus, viz., M. hypericifolia, which latter species has, however, other specific differences sufficient to warrant a systematic differentiation. The inflorescence of the two also shows marked distinctiveness. The leaves of this species have the peculiarity of f neuanGe unless pressed as soon as gathered. Leaf Histology.— As this plant hasa convex leaf a trans- verse section gives a vinculum figure. The leaf is chan- nelled above so that two convex surfaces form the upper cuticle, which is characterised below by a very much thicker development of palisade parenchyma than the | upper surface, as shown in the plate. The spongy paren- chyma is fairly limited in area, the cells being circular in cross section. Stomata occur on both surfaces, and are. rather more numerous than obtains in other species of AUSTRALIAN MELALEUCAS AND THEIR ESSENTIAL OILS. dio Melaleuca examined, and what might be expected, more so in the channel of the midrib. Bundles occur through the median line of the spongy parenchyma, the central vascular bundle,—the midrib, of course, being the largest. It is normally orientated and entirely surrounded by a thin layer of sclerenchyma fibres. The medullary rays being well defined, the cells increasing outwards in size. Essential Oil.—The oil of this species is another instance of the differences in the characters and constituents of those obtainable from the various species of Melaleuca, as it has little resemblance to that of ordinary ‘‘cajuput.’’ There appears to be an entire absence of pinene in this oil, the terpene present being limonene and probably dipentene. The principal constituent is a high boiling one, and no less than 67 per cent. of the total oil came over between 260 — 276 (corr.), This high boiling fraction consisted principally of a sesquiterpene, and asit occurs in the oil of this species in such large quantity it should be possible to work out its chemical characteristics and combinations, and so deter- mine whether it is new to science. It is dextro-rotatory, and the optical rotation of the purest sample so far obtained, Was dp = + 85’. Its specific gravity is somewhat high = 0°9364 at 15° C., and its refractive index at 21°C. = 1°5004. It boils between 260 — 270° ©. It has marked colour reactions when two drops of oil are dissolved in 10 cc. selvent, and shaken with one or two drops of sulphuric acid. (a) If the solvent is glacial acetic acid the colour is pink at once, soon changing to crimson, and then to pur- plish-brown on long standing. (b) If the solvent is acetic anhydride the colour is bright green at once, soon becoming darker green, and deep blue on long standing. (c) If the vapours of bromine are passed over a film of the oil on a watch glass, the colour is bright blue and violet at once, changing to green on standing. 374 R. T. BAKER AND HENRY G. SMITH. (d) If the vapours of bromine are allowed to fall down a test tube on to a solution of two drops in glacial acetic acid, a violet colour at once forms, changing to indigo-blue on standing. This sesquiterpene appears to be present in the high boiling portions of the oils of many species of Melaleuca, and the above colour reactions are readily obtained with them. The amount of cineol in the crude oil is but small, it was determined by the resorcinol method in the first fraction, and calculated for the crude oil. The whole of the cineol was removed from the first fraction by the aid of 50 per cent. resorcinol, and the separated terpenes again rectified. Nothing distilled below 175° C. (corr.), so that pinene cannot be present but in traces. The greater por- tion of the terpenes distilled between 175-178° C., and gave other indications for limonene or dipentene. The ester in this oil is probably terpinyl-acetate, as the acid was determined as acetic, and the odour of the separated oil, after saponification, reminded strongly of terpineol. Free terpineol is probably also present, as on boiling the oil with acetic anhydride and anhydrous sodium acetate in the usual way, over 5 per cent. of an alcohol was shown to be present. ) The high boiling fraction when agitated with acetic anhydride did not easily dissolve, so that it was possible to remove largely the ester and the free alcohol from the sesquiterpene by the method of agitation. Bie Experimental.—The material was collected at Gosford, in this State, and distilled in January, 1911. 208 ibs. of material (leaves and terminal branchlets) gave 10 ounces of oil, equal to 0°3 per cent. The crude oil was of a dark amber colour, somewhat viscous and greasy in appearance —similar in this respect to the oil of M. bracteata—and AUSTRALIAN MELALEUCAS AND THEIR ESSENTIAL OILS. 375 left a permanent stain on paper. It had a somewhat pleasant odour, probably due to the terpineol present. The crude oil had the following characteristics :— Specific gravity at 15° ©. be iso = :0°9302: Optical rotation dp... ae i Fea dn oir a Refractive index at 24°C. ... SEA ots Cineol (determined by the resorcinol method) = 8°7% Saponification number of ester + free acid = 8°25. Scarcely soluble in 10 volumes 80 per cent. alcohol. For distillation 100 cc. were taken. A few drops only of acid water and volatile aldehydes came over below 177°C. (corr.). Between 177 —218° 29 cc. distilled. The ther- mometer then quickly rose to 260°, and between that temperature and 276° 67 cc. came over. The specific gravity of the first fraction at 15° C. = 0°8801; of the second — 0°9382. The rotation of the first fraction a) = + 3°4°; of the second = + 7°8°. The refractive index of the first fraction at 24° C. = 1°4767; of the second=1°4991. After the removal of the cineo!l in the first fraction by resorcinol, the portion of the terpenes distilling between 175 -— 178° C. had specific gravity at 15° OC. = 0°8572; rotation a> = + 4°9°; refractive index at 22° C. = 1°4769. The fraction had the odour of limonene. When tested for the tetrabromide a few crystals formed, but they were difficult to separate, neither phellandrene nor sylvestene were present, and all the indications go to show that the terpene in this oil is limonene, or dipentene. The saponification number for the ester in the large high boiling fraction was 9°2, equal to 2°16 per cent. of terpinyl- acetate in the crude oil. A portion was then esterised in the usual manner when the S.N. had risen to 36°6, repre- senting 5°05 per cent. of free alcohol as terpineol in the crude oil. Methyl eugenol and the ester of cinnamic acid appeared to be both absent in the oil of this species. 376 Rk. T. BAKER AND HENRY G. SMITH. _ Material of this species was also received from Port Macquarie, in this State, and distilled November 1910. In general appearance and characters it resembled the oil from the Gosford sample, and was even more viscid. The specific gravity at 15° C. = 0°9552, which is higher than that of the sample from Gosford. The refractive index at 24° OC. = 1°4923. The saponification number of ester + free acid = 81. The rotation was not sharp, but it was between two and three degrees to the right. EXPLANATION OF PLATES. Plate XVI. Melaleuca genistifolia. Figs. 1 and 2. Flowering twigs. ,, 2 Individual flower. . Individual bundle of stamens. . Individual leaf. . Individual early fruit. . Individual fruit with contracted rim. CON & Oe . Cluster of fruits. 1, 2, and 3, natural size. Plate XVII. Fig. 1. A cross section through the centre of a complete leaf, showing the general disposition of the parenchymatous tissue, oil glands and vascular bundles. x 110 Fig. 2. A cross section through half a leaf, towards the upper | portion. |x 110: Plate XVIII. Fig. 3. A transverse section through little more than half a leaf. The midrib on the extreme right is surrounded by sclerenchy- matous fibres shown black in the plate; a smaller bundle is on the extreme left towards the edge of the leaf. Other rudi- mentary bundles are seen in the median line but not sur- rounded by fibres as in the case of the other two. A few oil glands are seen. x 141). AUSTRALIAN MELALEUCAS AND THEIR ESSENTIAL OILS. 377 Plate XIX. Fig. 4. This is a higher magnification of the midrib or main Fig. Fig. bundle in Fig. 3. The dark cells are sclerenchymatous tissue, and this is now seen to much greater advantage here than in that figure. The larger crescent shaped cluster is towards the underside of the leaf, the concave face butting on to the phloem with its cell walls scarcely discernible. The xylem cells succeeding these upwards have thicker cell walls and are quite distinct. The larger cells in the outer field are those of the spongy parenchyma. x 450. Plate XX. 5. This is another section of a leaf cut without bleaching out the cell contents, consequently the presence of manganese compound is marked by the dark substance in the lumen of the spongy parenchyma. Three oil glands are shown. The chloroplastids are distinctly seen in each cell. x 140. Melaleuca gibbosa. . 6. A transverse section of just a little more than half a leaf, the midrib or central vascular bundle being on the left of the picture, to the left of which is a large oil gland. x 140. Plate X XI. g. 7. A slightly larger section of a portion of a leaf between the midrib and edge, and showing chloroplastids in the cells of the palisade parenchyma. The upper surface of the leaf has the papillose projection of the cuticle. x 150. 8. Similar to figure 7, but a large oil gland is to the right ef the main bundle in this case, thus showing how irregularly the oil glands are distributed throughout the leaf. x 140. Plate X XII. . 9. A cross section through more than half a leaf, towards the petiole. x 110. Plate XXITI. g. 10. A cross section through the centre of a leaf towards the petiole, showing how the palisade parenchyma is displaced by 378 Fig. R. T. BAKER AND HENRY G. SMITH. the spongy parenchyma in the upper portion of the leaf over the central vascular bundle, and beyond. Only one whole oil gland comes into the field of vision. x 140, Plate XXIV. . 11. A cross section through the central bundle of a leaf and surrounding tissue cut from the upper portion of the leaf. Here the palisade parenchyma is in its normal position, and the mass of sclerenchymatous fibres surrounding the central bundle are distinctly seen. This section also shows clearly the papillose projections of the cells of the cuticle on the ventral surface, and these are the first so far met with in Melaleucas. Ina few of the spongy parenchyma cells cal- cium oxalate crystals can be seen. x 225, Melaleuca pauciflora. 12. A cross section through a two-thirds portion of a leaf. The bundle is normally orientated, the channel denoting the — upper or ventral surface, towards which it will be noticed that the palisade parenchyma is more strongly developed than on the dorsal surface. The oil glands it will also be seen are not numerous. Here also as in WM. gibbosa the spongy parenchymatous cells bound the central bundle on the dorsal side. Several bundles occur on the median plane of the leaf texture, two at the extremities of the picture being cut obliquely. Four crystal sacs occur in the palisade paren- chyma of the upper surface towards the right, and in two, rhomboidal crystals are well outlined. x 110. | GEOLOGY OF ERUPTIVE AND ASSOCIATED ROCKS, POKOLBIN. 379 THE GHOLOGY or THE ERUPTIVE anp ASSOCIATHD ROCKS or POKOLBIN, NEW SOUTH WALKS. By W. R. BROWNE, B.sc., and A. B. WALKOM, B.&c., Demonstrators in Geology, University of Sydney. With Plates KXXV—XXVIII. [Read before the Royal Society of N. S. Wales, December 6, 1911.} I. Introductory. II. Physiography and Preliminary. III. Faults. | IV. Geological Age of the Formations. V. Geology—A. Carboniferous Rocks. Drake’s Hill Area. ‘Mount Bright Area. Matthews’ Gap Area. B. Permo-Carboniferous Rocks. VI. Order of Succession. VII. Petrology. VIII. Summary. TX. Conclusion. Introductory. The district which it is proposed to deal with in this paper is situated in the County of Northumberland, about Six miles from the town of Cessnock. The eruptive rocks lie in the Parishes of Rothbury, Pokolbin and Milfield, and comprise an area about six miles long by about two miles broad at the widest part, the longer axis being roughly north and south. ~ So far aS we are aware, no detailed description of the igneous rocks of this district has hitherto been published. In Professor David’s “Geology of the Hunter River Coal- 38U W. R. BROWNE AND A. B. WALKOM. field of N.S.W.,’’ Part I,* there are allusions to Pokolbin, and the eruptive complex is referred to as a Carboniferous inlier. A sketch map is given, and some sections indicate suggested relationships between the rocks, which are referred mainly to Carboniferous times, with some con- temporaneous lava flows in the Lower Marine of the Permo- Carboniferous. This is, to the best of our knowledge, the only place in geological literature where reference is made to the igneous rocks of Pokolbin. We propose to treat the district in some geological detail, since, though it is of no very great extent, it possesses a very interesting geological history. For convenience of treatment and reference the district will be divided into three areas :— (i) The Drake’s Hill area, extending from a point about half a mile north of the southern boundary of the Parish of Rothbury to ‘‘Maluna”’ homestead. (ii) The Matthews’ Gap area, from Maluna to Mat- thews’ Gap. (iii) The Mount Bright area, from Matthews’ Gap as far south as the “Jerusalem Rock’’ and Mount View School, including the northern portion of Mount Bright. These areas are by no means to be separated geologically or petrographically, as we shall endeavour to show that the rocks of the whole district, with a few exceptions, are to be considered as forming part or all of a geological unit. Physiography and Preliminary. The northern portion of the district forms a chain of foothills to the Brokenback Range, whose steep scarp runs in a general E.S.H. direction as far as Matthews’ Gap, where it takes a sudden turn tothe east. Continuing thus * Memoirs of Geol. Surv. N.S.W., Geology No. 4, 1907. 4 1 ” GEOLOGY OF ERUPTIVE AND ASSOCIATED ROCKS, POKOLBIN. 381 as far as Mount Bright, it once more turns H.S.E. and follows an irregular course. The range forms part of the boundary of the old Hunter Valley, which extends for many miles to the east as a generally level plain. This range probably represents the remnant of a ge-anticline of Permo- Carboniferous rocks which had a roughly meridional axis. It is composed of Permo-Carboniferous sediments dipping to the west, capped by gently dipping Triassic sediments— the Narrabeen Series and Hawkesbury Sandstone. At Matthews’ Gap, where the range turns eastwards, the eruptive rocks are encountered, and of these the range is composed as far as the southern boundary of the district we have to deal with. Professor David considers that, subsequent to the eruption of the lavas of this district, marine conditions obtained, and the eruptive masses existed as islands or at all events as submarine elevations in the Permo-Carboniferous sea. EHlevation and denudation have laid them bare again, above sea level. At present the physiography is a mixture of maturity and youth. Itis evident on the one hand that a considerable amount of dissection and denudation took place before the deposition of the Permo-Carboniferous sediments, as conglomerates can often be traced filling in what were Permo-Carbonifer- ous valleys and containing pebbles of the Carboniferous rocks. Furthermore some of the hills of to-day must be substantially as they were at the close of Carboniferous times, as we find the conglomerate dipping off their flanks with comparatively little evidence of further denudation. Drake’s Hill is a case in point. On the other hand, Post-Triassic erosion has in many places cut into the eruptive rocks, and the work of dissec- tion is still proceeding. In the Matthews’ Gap area the youthful physiography of the country is particularly evident, V-shaped valleys being formed with eruptive rocks on 382 W. R. BROWNE AND A. B. WALKOM. either side, while the steep eastern scarp of the range from Mount Bright to Mount View also betrays youthful physio- graphic conditions. | Two examples of imminent stream capture on a small scale are to be seen near Matthews’ Gap, within a quarter of a mile of one another, where two parallel branches of Moogering Creek are eroding back towards Flying Fox Gully which is flowing at a higher level than the other creeks, in a direction perpendicular to them and with a much gentler grade. A reference to the contour map will make evident the very short distance which remains to be eroded in both cases. Faults. Although there is evidence of extensive and complicated faulting very little can be definitely determined with regard to it. This is due to the fact that much of the faulting occurred probably as early as Mesozoic times, so that all surface evidence has long been obliterated, and the exist- ence and position of the faults must be inferred from geological considerations. Professor David has determined, on stratigraphical grounds, aseries of faults affecting the beds of the Permo- Carboniferous, and it is quite likely that in connection with these main movements minor faulting occurred in the eruptive rocks of the district. A very marked line of fault- ing is that along the eastern face of the range from Mount Bright to Mount View. In fact two almost parallel faults seem to be indicated here. The evidence is both physio- graphic and geological. The bold scarp of rhyolite, per- pendicular in places, and towering to a height of 600 feet above the plain, isa very marked feature of the landscape, and at once suggests a very recent fault-scarp, while the fact that rhyolites and Permo-Carboniferous conglomerate are found along the top of the range on its western side, CONTOUR MAP OF MATTHEWS GAP & MT. BRIGHT Fig. 1.—Contour;Map of Matthews’ Gap and Mount Bright Areas. 384 W. Kk. BROWNE AND A. B. WALKOM. and at the plain level on the eastern side, is undoubted evidence of local vertical movement. This fault, the more easterly of the two, is the older. Two other small and doubtful faults are shown on the map, at Post Office Hill, and at the place named Jerusalem Rock. In both cases the throw is probably small and the evidence for the fault- ing is mainly physiographic, showing that such faults, if they really exist, are of comparatively recent origin. Other faults, postulated on geological grounds and noted on the map, will be referred to as they occur, in dealing with the general geology of the district. Geological Age of the Formations. In this district there are representatives of two, and possibly three, geological periods. -The principal and most interesting series, comprising acid, intermediate and basic lavas, is of Carboniferous age: in the Lower Marine of the Permo-Carboniferous, basic lavas and tufis are developed : while underlying the Carboniferous lavas of Mount Bright is along narrow outcrop of grano-diorite which is either Lower Carboniferous or Pre-Carboniferous. Itis with the Carboniferous lavas that we are chiefly concerned in this paper. Round the gently sloping elevations comprised in the Drake’s Hill area the basal conglomerates and sandstones of the Lower Marine can be traced in such a way as to leave no doubt that they actually surroundit. They appear dipping at a low angle off the igneous rocks, so that it may be concluded that Drake’s Hill was an isolated elevation on the floor of the Permo-Carboniferous sea, against the sides of which these sediments were deposited. This con- glomerate contains pebbles of the rocks of which the inlier itself is composed, so that the eruptives are anterior in age to the Permo-Carboniferous. The age of the Matthews’ GEOLOGY OF ERUPTIVE AND ASSOCIATED ROCKS, POKOLBIN. 385 Gap rocks has been determined on similar evidence, and by the fact that a tuff bed has been found containing Carboniferous fossils. A very definite and persistent horizon of Lower Marine conglomerate can be traced in many places from “‘ Maluna”’ homestead as far as Mount View; this forms a very con- venient datum bed, as it immediately overlies the Carboni- ferous rocks. The conglomerate is unfossiliferous and, apart from local inclusions of the underlying rocks, is characterised by very much rounded pebbles of quartz-por- phyry and quartzites from some unknown locality. The conglomerate can be traced on both the eastern and western sides of the Mount Bright area. At one point on the western side, about one and a-half miles north of Mount View School, a beautiful section shows the sequence from the Carboniferous rhyolite through Carboniferous con- glomerate, shales and grits to Permo-Carboniferous con- glomerate and sandstone. At this point the latter are at least 200 feet thick, the unconformity between them and the Carboniferous being very slight. That the Mount Bright grano-diorite is considerably older than the Carboniferous rhyolites has been definitely proved by the finding of pebbles of grano-diorite in the rhyolite and tutis at different points along the junction oi the two rocks. Since considerable denudation must have been necessary to lay bare the plutonic rock before the rhyolite flowed over it, the grano-diorite must be referred to the Lower Carboniferous or some anterior period. Geology of the Three Areas. A—CARBONIFEROUS ROCKS. The Drake’s Hill Area.—The rocks consist mainly of rhyolite, rhyolite breccias and tuff, trachyte, and a number of isolated patches of andesite. The rhyolitic rocks are Y—Dee. 6, 1911. YY ¥ Ts 7 4 ' 386 W. R. BROWNE AND A. B, WALKOM. mostly on and around the Post Office Hill, and have under- ~ gone very violent and extensive contortion, apparently when in a plastic condition and also subsequent to consoli- dation. The rhyolite is as a rule strongly banded, and the even course of the banding is often broken by folds varying from a fraction of an inch to several feet across. Persistent tilting of the rock mass is observed, the flows dipping at various angles in an average direction of about N. 10° HE. The beds are cut off abruptly by the small submeridional fault already referred to, which also at its southern end throws down the trachyte against the rhyolite. The rhyolite is mainly of the glassy type, no porphyritic quartz crystals being seen as is the case with the Mount Bright rock. What appears to be secondary material of a jasperoid nature, dark brown to black in colour, is of fre- quent occurrence. There is evidence of several successive flows in this area, the earlier of which were brecciated by the later eruptions. Fine rhyolite tuff also occurs in con- siderable abundance, and a hard green tuff which is spar- ingly found seems to be a modification of the rhyolite tuffs. Trachyte overlies and partly surrounds the rhyolite. It is in places of a tuffaceous nature, and is of the leucocratic or acid type, light brownin colour. The andesite probably represents the remnants of former flows on top of the trachyte or intrusive into it. An outcrop of chocolate shales and dark coloured con- glomerate is exposed in the bed of a creek on the Rothbury Road, not far from the Post Office. These are entirely different in appearance and constitution from the known Permo-Carboniferous rocks, for which reason they have been put down as Carboniferous and correlated with similar occurrences in the other areas. Monnt Bright Area.—Here a very much older formation is met with in the shape of grano-diorite; as its age may 4 i : GEOLOGY OF ERUPTIVE AND ASSOCIATED ROCKS, POKOLBIN. 387 be Carboniferous, it may be conveniently be treated here. It outcrops in a long narrow band along the eastern face of the range between Mount Bright and Mount View. The typical rock is medium-grained, with a slight preponderance of light over dark coloured minerals. At the northern limit of the occurrence two extremely well marked types of local differentiation products occur, the first being a basic modification, much darker in appearance than the general type. From examination of hand-specimens the ferro-magnesian constituents hornblende and biotite are seen to predominate, forming about 80 per cent. of the rock, while the remainder consists of plagioclase, pink orthoclase and a little quartz. A short distance away a further modification appears in the shape of a pink aplite, consist- ing of porphyritic laths of plagioclase, showing albite and carlsbad twinning, in a fine-grained base of quartz and felspar with subordinate biotite. Pyrites in very small crystals is abundantly distributed. The aplite in places also contains irregular small patches of tourmaline, and large segregations of the same mineral showing fibrous radial structure also occur, probably as a result of pneu- matolytic action. The final phase of differentiation of the grano-diorite magma is represented by a pegmatite. This rock is extremely coarse in texture and consists of an intimate intergrowth of allotriomorphic to subidiomorphic quartz and pink felspar. At this northern end the grano- diorite is cupriferous, the copper minerals being in close association with the pegmatite. Azurite, malachite, pea- cock ore, pyrites, etc., have been obtained near the upper boundary of the grano-diorite, but the workings are now abandoned. Attempts to find copper near the Mount View end of the outcrop have proved unsuccessful. Rhyolite and rhyolite tufis are the earliest of the Upper Carboniferous volcanic series, and form the greatest part i » " 388 W. R. BROWNE AND A. B. WALKOM. of the rocks of this area. The rhyolite here does not appear to have suffered so severely from earth movements: as that of Drake’s Hill, and in appearance differs from it in many respects. Typically the Mount Bright rock is whitish to dark red in colour, sometimes, but not invariably, strongly banded and containing small idiomorphic quartz and felspar crystals sparsely distributed. Secondary chalcedony is found, opaque yellowish to red in colour. On the edges of the area a coarse agglomerate is. developed, containing boulders of banded rhyolite up to about a foot in diameter. This may have been produced towards the close of the rhyolite eruptions or may repre- sent the result of the first explosive outbursts of trachytic lava. Overlying the rhyolite, and filling in eroded hollows. in it, are flows of trachyte of considerable extent, gener- ally yellowish-brown in colour and containing small laths. of felspar in an aphanitic base. The relations of this. trachyte to the rbyolite are very definite. Only three very small occurrences of basic rocks have been observed among the Carboniferous eruptives, in the shape of what appear to be small necks of basalt and dolerite. The mineralogical and structural points of similarity con- necting these occurrences suggest that they should be correlated, but as the occurrences are isolated from other basic rocks their precise geological age is difficult to determine; all that can be said is that they are post- trachyte. Resting directly upon the acid lavas and underneath the Permo-Carboniferous conglomerate is a Carboniferous sedimentary series, consisting of conglomerates, fine grained friable chocolate shales and tuffaceous sandstones: some or all of the members of this series can be traced at many points around the area, and up into the Matthews’ Gap area. They are well seen on the road about half a mile: 7 3 GEOLOGY OF ERUPTIVE AND ASSOCIATED ROCKS, POKOLBIN. 389 N.W. of Mount View School, where the whole sequence from the rhyolite to Lower Marine conglomerates can be traced, the Carboniferous sediments dipping at about 12° off the rhyolite and attaining a thickness of 400 feet. On the western side the formation appears as tuffaceous sand- stones, in close association with rhyolite agglomerate, and containing obscure plant remains. On the eastern side the greater part of the sediments has been faulted out of sight, ia save in afew places where small outcrops of chocolate shales are | seen. Kear The exposure of the grano- diorite in this area is probably the effect of the older Mount Bright fault. A glance at the tel} Oe \. maps and at Section 1 will serve oa \ to explain how the faulting has ie Be brought down the rhyolite to a = on much lower level and thrown it against the grano-diorite, at the Ye \ Rhyolite 3 Tuffs os NS7, ane N! same time exposing the latter. é5 - We = Matthews’ Gap Area.—While 45 this area is continuous with the S : ae w others in respect of the more Ox F Se acid lavas, the occurrence of 12 ° ° eo more basic rocks is better uo wy marked as regards both extent and variety. The rhyolite tufis appear as isolated outcrops mostly confined to the northern end, but nearer Matthews’ Gap itself the rhyolites are com- pletely hidden under trachytes, So) basalt, agglomerate, trachy- 390 W. R. BROWNE AND A. B. WALKOM. andesite, and dacite, with patches of Permo-Carboniferous quartz-porphyry conglomerate dipping off the eruptives or | filling in old valleys. The tufis or breccias are of a some- what different variety from those occurring at Drake’s Hill and Mount Bright. They are medium in texture, the fragments being up to about two inches long, and ranging down to microscopic dimensions. The inclusions comprise fragments of cherty rock, rhyolite of various colours, trachyte of a kind not met with in the flows of the district and therefore probably of much earlier date, and fine-grained green siliceous-looking rock probably closely related to the green tuff of Drake’s Hill and to another tuff found else- where in the Matthews’ Gap area. The latter seems to be a variety of the rhyolite tuff. It is extremely fine-grained, of a blue-green colour, hard and compact. Its chief differ- ence from the Drake’s Hill green tuff consists in the presence of abundant felspars, largely idiomorphic, but often with the appearance of angular fragments, suggesting that they are of extraneous origin—not crystallised in the tuff. Some other very fine grained tufis are found occurring om top of the coarser rhyolite tufis, in particular that already referred to as containing the Carboniferous plant fossils. Rhacopteris and Cardiopteris, also an extremely fine- grained greenish-white cherty tuff which is to be found on the N.W. end of Mount Bright. Both of these are stratified,. and the Rhacopteris tuff isin places fractured and shattered. the pieces having slipped on each other, excellent miniature examples of different kinds of faulting have been produced. Trachyte is very abundant, and has followed directly on the rhyolite and tuffs. It may be divided into two varieties, leucocratic and melanocratic, this division being based on a microscopic comparison of the two types. It is more fully discussed below. The leucocratic trachyte is of a. GEOLOGY OF ERUPTIVE AND ASSOCIATED ROCKS, POKOLBIN. 391 brownish colour, similar to that in other parts of the district, with small phenocrysts of felspar showing macro- scopically. The melanocratic variety is much finer and more even grained, and is of a bluish colour, having the general appearance of a rather light-coloured basalt. The leucocratic type has the wider distribution, and is the older of the two types: on top of it the Carboniferous sedimentary rocks, represented by sandstones and conglomerates, have been deposited. On top of the conglomerate are further flows of trachyte, both the leucocratic and melanocratic varieties, accompanied by dykes and sills in the conglomer- ate. More basic rocks succeed, the most extensive and important being a coarse agglomerate associated with basic looking tuffs, which are capped by trachy-andesite and andesite. The blocks in the agglomerate are often rounded, giving the appearance of a coarse conglomerate; they include rocks of a felsitic nature, with pebbles of a green tuffaceous-looking rock, and the cementing material is of a dark basic appearance, but of undetermined composition. The whole of this series is well exhibited on the long ridge along which run the old and new roads to Matthews’ Gap. Probably connected with the same outbursts is the inter- mediate glassy rock or pitchstone, of which a couple of isolated outcrops are found and of which an analysis is given below, and the andesite in the N.W. portion of the area. The most basic portions of the Matthews’ Gap area series are a flow of basalt and associated tufts. The last phase of the volcanic activity of Carboniferous age is represented by a flow of dacite, which partially con- ceals the outcrop of many of the earlier rocks, and which is immediately under the Permo-Carboniferous conglomerate in some places. - Dykes of leucocratic trachyte in the agglomerate and trachy-andesite may belong to the same phase. Bi be Conglomerate & Sandstone re--- -Permo-Carbs. -----4 Leucocratic _ oS ps ée za of ond 2 On U Fault m Section 2 W. R. BROWNE AND A. B. WALKOM. The western extension of the agglomerate outcrop is cut off under this dacite, but on the eastern side it abruptly joins the Mount Bright trachyte, and is seen no further south. A similar sharp boundary exists for the trachy-andesite and Mount Bright trachyte, and these circumstances indicate a faulted junction. (Vide Section 2.) Another small fault is probably to be placed to the east of the old road, letting down the Car- boniferous conglomerate and trachyte a vertical distance of about a hundred feet. No great extension of this fault can be traced, whence it may be argued that it antedated the agglomer- ate and consequently the dacite. A line of fracturing and crushing is developed in the dacite, whereby a typical crush-breccia has been produced. Every phase can be traced, from the unjointed rock, through a highly jointed zone toa zone of intense fracture and lateral movement. This is however, merely a local phe- nomenon. A fault on the extreme west of the area which has brought —s GEOLOGY OF ERUPTIVE AND ASSOCIATED ROCKS, POKOLBIN. 393 the Upper Marine sandstones into juxtaposition with the Carboniferous formations is probably part of the Elderslee fault of Professor David which has caused the burying of the Greta coal measures to a considerable depth. B. PERMO-CARBONIFEROUS ROCKS. . These have not been studied in detail, but their relation- ships have been noted where they are contiguous with the Carboniferous rocks. The most notable among the sedi- mentary series is the quartz-porphyry conglomerate, which in this district appears to form the lowest of the Permo- Carboniferous strata. It has been suggested, however, that any possible lower beds have been concealed through overlapping. The conglomerate sometimes disappears and then the eruptives are immediately overlain by the Lower Marine sandstones. The igneous rocks are confined to basalt and tuffs con- temporaneous in the Lower Marine. The position of these is indicated in the geological map, and it will be observed that in the southern portion of the district they exist as a marginal belt to the Carboniferous rocks. They occur some distance up in the Lower Marine, intrusive through the basal conglomerate and some of the overlying sand- stone. Their contemporaneity is proved by the presence of Stenopora and Fenestella found by Professor David in the associated tuffs on the western side of the Mount Bright area. A considerable extent of the basalt on this western side is amygdaloidal, the steam holes being filled with zeolites, chiefly radiating aggregates of natrolite, often in fairly large masses, with associated minor development of pinkish datolite and analcite. It is a remarkable circumstance that similar occurrences are not met with in the basalt on the south and east of the area. 394 W. R. BROWNE AND A. B. WALKOM. The country between the Drake’s Hill volcanics and ‘‘Maluna’’ is composed principally of Lower Marine sediments—conglomerate, sandstone and foraminiferal limestone. A belt of basaltic or andesitic lava can be imperfectly traced by means of the resulting soil and by a few obscure and decomposed outcrops, but this has not been accurately mapped, as the boundaries are impossible of delimitation. North of the Drake’s Hill area, in the Parish of Rothbury, is a small low conical hill composed of basalt, with a few short dykes radiating from it. The relations of this outcrop are much obscured by recent alluvium, but it is in all probability contemporaneous in the Lower Marine. It is surrounded by Lower Marine sandstones which a short distance away are distinctly dipping towards the outcrop. Order of Succession of the Lavas. As a result of our investigations we are inclined to advance the following order of succession for the rocks of the district :— Carboniferous : i. Rhyolite and rhyolite tuffs. ii. Trachyte, beginning with leucocratic, and followed by melanocratic. ili. Agglomerate, trachy-andesite and andesite. iv. Dolerite and olivine basalt necks, and basalt flows. v. Dacite and (?) dykes of trachyte. Permo-Carboniferous : vi. Basalt. The positions of the rocks under iv, and of the trachyte dykes are of course not certain, but there is little doubt that the general character of the succession is correct. There seem to have been several eruptions of rhyolite, both as quiet flows and as explosive outbursts. The trachyte GEOLOGY OF ERUPTIVE AND ASSOCIATED ROCKS, POKOLBIN. 395 followed on the rhyolite apparently without any consider- able interval. Succeeding the trachyte was a period of quiescence in the vulcanicity and of gradual subsidence, during which the Carboniferous conglomerates, shales and sandstones were laid down, before volcanic action recom- menced. The longest period of volcanic inactivity was probably that between the dacite and the Lower Marine basalt. During this interval the Permo-Carboniferous sedimentation began and advanced to a considerable degree. Petrology. The rocks found in the district include, as has been already shown, a wide range of types. They may be divided up as follows :— A. Plutonic, B. Hypabyssal, and ©. Volcanic (i) acid (ii) intermediate, and (iii) basic. The only plutonic representative is the grano-diorite mass exposed along the eastern face of Mount Bright. Hypabyssal rocks are represented by the dolerite at Matthews’ Gap which occurs aS a (?) volcanic neck, and the small neck of ophitic dolerite in the Mount Bright area. The acid vol- canics include the rhyolites and the dacite, both occurring as flows, and probably the leucocratic trachytes can be classed with these. The intermediate volcanics include the melanocratic trachyte (which in hand-specimens resembles very closely a light coloured-basalt), trachy- andesite, andesite and pitchstone. Among the basic rocks there are olivine basalt, and basalt. One of the most noticeable features of the volcanic series is the extremely limited development of ferro-magnesian constituents. This is very marked in the trachytes and =e » 1 ‘ ~ po ° . ‘ 396 W. R. BROWNE AND A. B WALKOM. andesites, which are almost devoid of such minerals. In some cases, however, a good deal of alteration has taken place, and it is possible that a good deal of the ferro- magnesian mineral has been replaced by secondary material, The norms of the two analyses of quite fresh rocks (andesite and pitchstone) calculated according to the American classification, show respectively 16°78 and 11°80 per cent. of pyroxene; from this it seems probable that there isa good deal of ferro-magnesian constituent present in the base though it cannot readily be distinguished under the microscope. A. Plutonic. Grano-diorite. Coarse-grained phanerocrystalline rock, consisting of quartz, felspar, hornblende and biotite as far as can be seen in hand specimen. Quartz and felspar form more than half the rock. Under the microscope the rock is holo- crystalline. Its grainsize is even and coarse, and the grains have an average diameter of about 2mm. The fabric is hypidiomorphic granular. The minerals present are:—Plagioclase, orthoclase, quartz, biotite, hornblende, magnetite, apatite and sphene. Plagioclase is the most abundant mineral; it is subidio- morphic and is twinned after the albite law. It is a good deal decomposed. The orthoclase is not so abundant but is present in fair quantity. Both the felspars are crowded with inclusions of tiny fragments of biotite, hornblende and magnetite. Quartz is present but not abundantly. The biotite is slightly decomposing to chlorite in places, and has a rather fibrous appearance. The hornblende is the green variety and is decomposing to chlorite. Apatite and magnetite are fairly abundant and sphene is sparingly present. The order of consolidation is: : GEOLOGY OF ERUPTIVE AND ASSOCIATED RUCKS, POKOLBIN. 397 Apatite Magnetite Sphene Hornblende Biotite _--eeeoeoeoee Plagioclase —_————— Orthoclase Quartz Ee ae ot B. Hypabyssal. Dolerite, Matthews’ Gap. A greenish coloured greasy-looking rock; phanerocrystal- line and fine-grained. Felspar and a dark ferro-magnesian mineral can be seen in hand specimen. Porphyritic cry- stals of pyroxene showing hour-glass structure are also visible. Under the microscope it is holocrystalline with a few porphyritic crystals. The base has medium grainsize. The fabric is hypidiomorphic granular. The minerals present are:—Plagioclase, augite, magne- tite, chlorite and calcite. The plagioclase is in tabular idiomorphic crystals, zoned and twinned after the albite, carlsbad and pericline laws. It is partly decomposed to kaolin, the decomposition often being zonal. A symmetrical section showing both albite and carlsbad twinning gives two symmetrical extinctions viz.:—244° and 374, indicating that it is labradorite with composition Ab,An,;. Augite is in large subidiomorphic crystals with zonally arranged inclusions. €10-0 | 010-0 | 900-0 |¢20-0 | 910-0 | 600-0 | 00-0! |810-0 | 210-0 | 800-0 | 100-0 | 800-0 | BIuomue o1uesI9 ‘g 08-8 SI-F 00-8 8.0 04-0 G8. 00-01 | O4-1T | 08-1T | 00-9 08-8 O€-IT |", 2° OUuloTEO °Z 88-2 | ZL.18 | Zo.F% | F9-9T | 9T-OT | 82-92 | 82-Eh | 48-99 | 96-19 | 00-28 | F2-2 | PH.49 | ONPISer pITos [VIOT, “T ‘S0°'SL'E |°60° 01°92 ‘80'S “60 01°93 ‘80°C € ‘80°OL'S | ‘80°OL'6Z | °80°01°6Z "60° 1S *80°OL'62 ‘*60°T'S ‘60'T'S ‘stsATVUy JO 93eq +(8) (L) (9) (a) (4) (¢) (2) (T) | “PaDUIwpyjuoyn punog s7ay asoy7 fo suajnv yy, 2Y2 fo s1azovLMY) JooIWaYyD) buineyg—]| WIAV, THE VALUE OF THE NITRATE FIGURE, ETC. 413 wells in Table II (wells well away from cesspits) the marked way in which the cesspit contamination has affected the nitrogen as nitrate figure will be seen. Taste II.—Showing Chemical Characters of Two other Well Waters for comparison with Waters from the Hight Condemned Wells. | (9) (10) Analysed Analysed 3.12.08. 29.10.08. 3.12.08. 1. Total solid residue ... ua ies LO°40" 13°24 14:64 2. Chlorine nee oe ven es 0:90 | 0°95 0°90 3. Organic ammonia ... Be sie 0001 0:°004 0°001 4, Free ammonia sie i Ee 0:002 0:006 0°002 5. Nitrites ae ee | 000" |) 0000 0-001 6. Nitrates a 1a a: 0-200 0°272 0-050 7. Oxygen avsorbed 15 minutes ua 0-008 0°012 0-008 8. Oxygen absorbed 4 hours ... Hs 0:012 0:020 0°012 9. Permanent hardness ns as 4°8 | ie 15 10. Total hardness i oe 6°0 | ee 10°5 11, Poisonous metallic contamination none none none 12. Alkalinity... ae a 1:2 ay 9°0 Figures equal to parts per 100,000. The following epidemiological evidence also pointed to these wells being contaminated :—Population of the town 508, living in 125 houses. During the twelve weeks 17th December 1908 to 7th March 1909 twenty-one cases of: typhoid fever occurred at this town, equal to an attack rate of 41 per 1,000 of the population for less than a quarter of the year. During the twelve months, March 1908 to February 1909, thirty-seven cases of typhoid fever occurred, equal to an attack rate of 72°8 per 1,000 of the population. The attack rate for the whole of New South Wales for the same twelve months was about 1°19 per 1,000 of the popu- yetion. Moreover, twelve cases occurred in one month, February 1909, constituting almost an “‘explosion”’ in such a small population. It will thus be seen to what an exces- sive degree this town suffered from typhoid fever. The possible effect that the contaminated water had on the typhoid incidence is shown by the next mentioned facts: 414 Cc. S. WILLIS. (a) Of the 37 cases occurring in the twelve months, 30 occurred on premises where there were wells ; (b) A large number of the cases occurred amongst people who, it is reasonable to suppose, had access to the wells actually condemned. Reference to attached map will show the relative positions of cesspits, wells and houses in which typhoid occurred. SUMMARY: (1) Personal inspection of the cesspits and the wells, com- bined with local evidence, proved that seven of the condemned wells were being polluted by soakage from cesspits. (2) Epidemiological evidence supported the conclusion that these wells were being contaminated by the cesspits. (3) Chemical evidence of the pollution of seven of the wells was furnished mainly by the large and the varying (in different wells) quantity of N as nitrates present in the well waters. THE HAEMATOZOA OF AUSTRALIAN BIRDS. 415 THE HAEMATOZOA or AUSTRALIAN BIRDS, No. II. By J. BURTON CLELAND, ™.D., chm., Government Bureau of Microbiology, N.S.W., and T. HARVEY JOHNSTON, M.A, D.Sc, Queensland University, Brisbane. With Plates XXX - XXXIII. [Read before the Royal Society of N. S. Wales, December 6, 1911. | IN a communication that we submitted to the Royal Society of South Australia last year, we detailed the results of an examination we had undertaken of the blood of vari- ous Australian birds for haematozoa. Since then, we have continued our observations, being greatly helped by the kindness of Dr. T. L. Bancroft, of Queensland, who has so materially assisted us with valuable material. To this pioneer of parasitology in Australia, science is indebted for much important work. . The results of these further exam- inations are incorporated in the present paper, including descriptions of halteridia, trypanosomes, embryo filariz, and other (presumed) parasites. Appended are lists of the additional positive and negative findings. The numbers (M. 7) etc., refer to the Hand-list of the Birds of Australasia published by Mathews in “The Hmu,”’ (Vol. vii, 1907-8). Halteridia in Australian Birds. In this further examination of Australian birds, halteridia were met with in 16 species. In 14 of these, they have not been recorded before, whilst in the other two, Zosterops coerulescens and Tropidorhynchus corniculatus, we have recorded their presence in our former paper and now extend their geographical distribution. In these halteridia, we have not attempted to define specific differences, merely stating the outstanding features 416 J. B. CLELAND AND T. H. JOHNSTON. noticed. We believe, however, that specific differences do exist between many of the forms, in as much as we find considerable variation in the size of the parasites, the amount of melanin, and the presence or absence of granules in the protoplasm. These differences are slight and hard to define and the question of specificity is perhaps best left to the future to decide. : Halteridium of Catheturus Lathami (M. 7). In this megapode, the *‘ Brush Turkey,’ these parasites were found in five out of six birds obtained by Dr. Bancroft near Hidsvold, Queensland. They were numerous in a specimen obtained in November and one in March: in four other March specimens, they were few in three and absent in one. The parasites themselves showed conspicuous male and female forms. They occupied one side and the ends of the host cells but did not overlap the nucleus on the far side. Pigment was prominent as coarse grains or rods, sometimes collected at one end. Vacuolar spaces (? arte- facts) were often present at one or both ends. Rounded forms, bulging the host-cell opposite its nucleus, were seen. Halteridium of Platycercus adelaidce (M. 336). Ina bird of this species shot near Adelaide in May, 1911, halteridia were found occupying nearly all the available space in the host cells except on the far side of the nucleus. Halteridium of Merops ornatus (M. 396). In the Bee- eater, halteridia were found in three out of four specimens sent by Dr. Bancroft from Widsvold, Q. The birds were secured in October, December and March. The parasites were present in moderate numbers and presented characters differing considerably, more especially as regards granules in the protoplasm. In the first specimen, the halteridia were half-grown and oval with very little pigment; in the second, they extended a little beyond the nucleus of the host-cell and were either pale or finely granular. Melanin THE HAKMATOZOA OF AUSTRALIAN BIRDS. 417 was present in small amount, either as a few fine grains near the centre, or one end, or as a rounded ball of grains atone end. In the third bird, deep blue granules were con- spicuous, crowded at or near the ends; and the parasites were elongated, occupying one side and most of the ends of the red cells. Melanin was again scanty in amount, being either in the centre near the nucleus or between it and the end. The special characteristics of this halteridium were the small amount of pigment and the deep blue granules. Halteridium of Microeca fascinans (M. 433). A series of nine specimens of this bird were obtained from Hidsvold, Q., of which eight, obtained in February, April and May, showed halteridia. In one of these obtained in April, trypanosomes were also present, whilst in two others, peculiar bodies elsewhere described, were present in the leucocytes. The parasites were, as a rule, fairly numer- ous and male and female forms were conspicuous. The melanin appeared as a few small grains or rods. The parasites occupied a large area of the host-cell, occasionally pressing the host-nucleus nearly against the opposite side, thus filling up practically all the available space. In films from two birds, specimens were found in which the parasite occupied one side and one end only of the host-cell. Another parasite, stained a fairly deep blue, showed a rounded nucleus located at one end with a few grains of pigment near it, whilst most of the pigment was located asa ballat the other end. Several oval forms were present in one bird, bulging the host-cell opposite its nucleus. Both blue and pale parasites were noted. Halteridium of Petroeca phcenicia (M. 440). Ina speci- men of this bird, shot on Mount Kosciusko (at 5,000 feet) in December, 1910, scattered halteridia, containing very little pigment, were seen. This bird is a wanderer, fre- quenting mountainous areas in summer time and plains, A 1—Dec. 6, 1911. 418 J. B. CLELAND AND T. H. JOHNSTON. often far away, in winter. The locality of infection is not necessarily that where the bird was shot. Halteridium of Grallina picata (M. 646). Halteridia were found in one bird out of three obtained at Widsvold, Q. The affected subject was obtained in April. There was a very heavy infection of the red cells, reaching ten or more per cent. The grains of melanin were small; many of the parasites were of an elongated oval shape, others typical halter forms. Halteridium of Aphelocephala leucopsis (M. 689). This bird was sbtained on the Murray Flats, 14 miles west of Blanchetown in South Australia, in May, 1911. Inthe red cells, halteridia were detected. The melanin appeared as large rods or granules. There were many rounded pale or deeper blue forms. Halteridium of Zosterops coerulescens (M. 712). In our previous communication, we have already recorded the occurrence of halteridia in birds of this species obtained in Sydney. We have now to record its presence in a bird obtained at Adelaide in May, and at Hidsvold, Q., in April 1911. Deep blue and pale forms were present. The para- sites occupied one side and most of the ends of the host- cells. The melanin appeared as small rods and granules. Halteridium of Pardalotus melanocephalus (M. 729). Fairly numerous halteridia were present in six out of ten (numerous in four) of these birds obtained ia April at Hidsvold,Q. Trypanosomes, but no halteridia, were present in a bird taken in March, and filarize, but no halteridia, in a specimen shot in May. The parasites were large, occu- pying one side and nearly all the ends of the host-cells. Melanin appeared as a few large grains near the centre or towards one end. The forms were deep blue or pale blue, some being almost colourless. In a bird taken in March, halteridia alone were found, while in two shot in May no THE HAEMATOZOA OF AUSTRALIAN BIRDS. 419 halteridia were detected, though microfilariz were present in one. Halteridium of Myzomela sanguineolenta (M. 746). In one of four specimens of this bird, obtained at Hidsvold in June, halteridia, as well as very long thin filarize and intra- corpuscular trypanosomes, were present. The parasites occupied the side and both ends of the host-cells and had fairly abundant coarse grains of melanin. Halteridium of Ptilotis fusca (M. 769). A few halteridia, together with intracorpuscular trypanosomes in two instances, were present in three out of nine specimens of this bird, obtained at Hidsvold in March, and in one bird obtained in April. The parasites occupied a relatively large area of the red cells. Halteridium of Ptilotis sonora (M. 772). A few halteridia were present in the blood-cells of a specimen of this bird obtained on the Murray Flats near Blanchetown, S.A., in May. The parasites occupied one side and most of the ends of the host-cells, and had a few coarse grains of melanin. Halteridium of Myzantha garrula (M. 804). Hight birds from Queensland were examined—seven came from Wids- vold and one from Gladstone. MHalteridia were present in three of the Hidsvold specimens, obtained in December (1) and February (2). The February birds also had filarie. Halteridium of Myzantha flavigula (M. 806). Ina bird shot at Rowena, in the north of New South Wales, in November 1910, halteridia were found. Melanin was present as fairly large rods. Halteridium of Entomyza cyanotis (M. 813). Ina bird shot at Hidsvold, Q., in October by Dr. Bancroft, a few halteridia were seen. This bird also showed ‘intracorpus- cular trypanosomes’ (elsewhere described in this bala? and a small species of embryo filaria. 420 J. B. CLELAND AND T. H. JOHNSTON. Halteridium of Tropidorhynchus corniculatus (M. 818). We have already described’ the halteridium present in this. bird as H. philemon. We have found it in a bird shot at Hidsvold, Q., in March, which extends its geographical distribution from New South Wales to Queensland. Halteridium of Oriolus sagittarius (M. 850). Halteridia were found in three of these birds obtained at Hidsvold in January, March and April. They contained moderately- sized scattered melanin granules. In two of these birds, ‘intracorpuscular trypanosomes’ were also present, in one of the two, free trypanosomes as well: the third bird had filarie. Trypanosomes in Australian Birds. In our previous paper we described the presence of try-- panosomes, which we called T. anellobice, in the honey-. eater Anellobia chrysoptera, the birds being obtained by Dr. T. L. Bancroft in Queensland. A further study of films from some of these birds, together with a series of specimens from other birds shot near Hidsvold, Q., also forwarded by Dr. Bancroft, has shown us a phase of these trypanosomes that we had previously overlooked. This consists in an intracorpuscular stage, the organism being a parasite (Leucocytozoon?) of the red corpuscles. That these intracorpuscular bodies are really stages of a trypano- gome, we think there can be no doubt. Not only is their body protoplasm stained in exactly the same way as that of free trypanosomes present in some of the films, but the macronucleus is also similar, and in a few favourable examples, the micronucleus has also been visible. It may be well, first of all, to describe the free and encysted forms in general. The free trypanosomes varied in form, some being very broad and others extremely narrow. Though the parasites 1 This Journal, 1909. THE HAEMATOZOA OF AUSTRALIAN BIRDS. 421 in any particular film were usually of one or other of these types, in some films both forms were present as well as others of intermediate size. The intracorpuscular forms were more or less globular, and lay in the protoplasm of the host-cell, embayed in the nucleus which sometimes surrounded the parasite so as to envelop three-fourths of its circumference. The bodies were uSually deeply stained blue, but occasional much paler forms were seen. As already stated they possessed a central macronucleus, and occasionally, near the periphery, what appeared to be a micronucleus was present. Considerable doubt existed for a long time as to the nature of the host-cell. Though the tinting of its nucleus was similar to that of an injured red cell (having the same reddish colour), irregular corona-like projections on the far side of the host-nucleus suggested that the cell might be a leucocyte. The question was, however, finally set at rest by detecting, in a film from Ptilotis fusca, very early intracorpuscular forms, without question parasitizing red cells. In one the protoplasm of the red-cell was still quite distinct, and its nucleus was being indented by the parasite so aS to form a kind of cap to it. Of course it is not impossible that mononuclear leucocytes may also act as host-cells. It is of much interest to note that our intracorpuscular trypanosomes (or ‘leucocytozoa’), while distorting the nucleus of the host-cell by indentation and stretching, in no instance cause the extraordinary elongation of host-cell and nucleus seen in Leucocytozoon ziemanni. This alone shows that the species are distinct. We think it highly probable that the trypanosomes and intracorpuscular bodies we have found in several Australian birds are all referable to the same species, and this we have already designated as Tryp. anellobiae. It will be seen 7 492, J. B. CLELAND AND T. H. JOHNSTON. that we have found free trypanosomes in five species of birds. In only one of these species have we failed so far to find intracorpuscular bodies. In addition, in four other species we have found the latter bodies without trypano- somes. Trypanosomes, when present, have always been few and more easily overlooked, whilst intracorpuscular bodies have usually been found with ease. TRYPANOSOMES—FE'REE AND INTRACORPUSCULAR. Free Trypanosomes of Micreeca fuscinans (M. 483). In one of these birds, obtained in May at Hidsvold, Q., free trypanosomes as well as halteridia were found. The para- sites were very broad and similar to those described later under Pardalotus melanocephalus. The posterior end was broad and irregular, the latter perhaps the effect of distor- tion; the body then narrowed rapidly to end in a short beak at the anterior end. The body was a deep blue, in some cases having an alveolar arrangement, in others showing streaky lines of fine bluish granules. There was a central macronucleus: the micronucleus appeared near the pos- terior end as a very conspicuous large deep purple dot or rod. A narrow undulating membrane was visible, but the flagellum was not definitely recognisable. No intracor- puscular phases were seen. Other specimens, four in number, obtained in April and May showed halteridia in three cases, but no trypanosomes. Free and Intracorpuscular Trypanosomes of Pardalotus melanocephalus (M. 729). In a bird obtained at Hidsvold, ()., in March, a few fine specimens of trypanosomes were found. The parasites were large and conspicuous, with a broad blunt posterior end from which the body narrowed uniformly to end in an elongated anterior end. The body was a deep blue with an alveolar appearance: a large macronucleus occupied the centre: a deep purple spot close to the posterior end indicated the micronucleus, from which THE HAEMATOZOA OF AUSTRALIAN BIRDS. 423 the flagellum, surrounded by the undulating membrane, arose and wound round the body to end in a short free flagellum. In addition, two pale oval bodies, about the size of the red corpuscles of the host, were seen with a small purple dot near one end: no macronucleus was detected: in one specimen was a short tapering ‘tail.’ The bodies suggested small phases of a trypanosome. No intracorpuscular bodies were seen in this specimen, though in one out of seven birds obtained in April, one of these bodies, embayed in the nucleus, was noted ; this bird had halteridia as well. Another of these seven birds showed bodies which probably also were intracorpuscular trypano- somes. In two May specimens filarize alone were found. Intracorpuscular Trypanosomes of Myzomela sanguineo- lenta (M. 746). In three out of four specimens of this bird obtained at Hidsvold in June, intracorpuscular trypanosomes were present. One of these also contained halteridia and filarize. Pale and deep blue forms were present. Free and Intracorpuscular Trypanosomes of Ptilotis fusca (M. 769). Of nine birds of this species shot at Hidsvold in March, one showed free trypanosomes alone, four showed free and intracorpuscular forms, in three, intra- corpuscular forms alone were detected, while in one no trypanosomes but a few halteridia were seen. In an April bird, intracorpuscular trypanosomes and halteridia were present. The free trypanosomes varied from moderately narrow, through a fusiform shape, to broad forms. The macronucleus was a little in front of the centre. The micronucleus was in some specimens close to the posterior end, in others decidedly further forward. The undulating membrane wound round the body, ending in a moderately short flagellum. The protoplasm took a deepish blue colour and corresponded in this and in its appearance to that of 424 J. B. CLELAND AND T. H. JOHNSTON. the deeper-coloured intracorpuscular bodies. In one speci- men, the micronucleus seemed to be dividing. The intra- corpuscular bodies were numerous in one bird, in which there were seen also occasional halteridia. Both full-sized dark and pale forms were present and also a number of much smaller forms, the smallest being about a fourth of the size of the largest. In the earliest form seen, the parasite was at one pole of the red cell, and the host nucleus was not yet distorted. The central macronucleus of the parasite was present and there was no pigment. In aspecimena little larger, the parasite was towards one end of the red cell, and, in the protoplasm of the latter beside it, was a small vacuole; beyond the vacuole, the host’s protoplasm showed a few scattered red dots. The nucleus of the host cell was redder than in an uninjured cell, slightly enlarged, not distorted but pressed to one side. Instill larger para- sites, the gradual embaying of the parasite in the nucleus of the host-cell was traceable through all its stages, from slight cupping onwards. In most of these young forms, the host-cells were clearly recognisable as red cells, about which there could be no mistake. In this film was also seen an apparently free vermicular form, rather like a heemogregarine with one edge slightly curved; the body was about as long as the red cells and as broad as their nuclei; its nucleus was nearer one end of the parasite. Intracorpuscular Trypanosomes of Myzantha garrula (M. 804). Four out of eight specimens of this bird from Hidsvold, Queensland, showed intracorpuscular trypano- somes. Two were obtained in February, one in December and one in May. In two specimens, the parasites were few, but in the other, a February bird, they were numerous. The parasites were, in many cases, pale in colour; two large examples showed bodies like micronuclei in addition to the macronuclei. THE HAEMATOZOA OF AUSTRALIAN BIRDS. 425 Intracorpuscular forms were found in the films from Anellobia chrysoptera from which we had _ previously described the free form. We had overlooked the presence of this phase. Free and Intracorpuscular Trypanosomes of Hntomyza cyanotis (M. 813). Both of these forms were present in two blue-faced honeyeaters obtained at Hidsvold in April. In one bird the trypanosomes were very narrow, in the other they were broad, approaching those of Microeca fascinans and Pardalotus melanocephalus. Bird 1.—The free trypanosomes were very narrow, with a Sharp-pointed posterior end and a similar anterior end. The body was vacuolated with a few deep blue granules : the macronucleus was near the centre, and the micro- nucleus near the posterior end. The flagellum and undu- lating membrane were not recognisable. Intracorpuscular bodies, similar to those to be described in Oriolus sagit- tarius, were present. In some of these parasites were a number (a dozen or so) of scattered small deep bluish gran- ules. One early form was seen in a red cell; it was oval, pale blue compared with the whitish host protoplasm, and lay to one side of the host nucleus, being as yet not embayed. It had a reddish elongated macronucleus, and two dark blue dots. Some pale, irregularly oval free forms were also seen, as if they had escaped from their host-cells. One of these was pale blue and slightly vacuolated; it had central purplish nuclear fragments, and at one end a broad deep purple dot resembling a micronucleus. Bird 2.—This bird showed much broader trypanosomes than the previous bird, approaching those of Pardalotus melanocephalus, though not quite so broad. The posterior end was broad, narrowing however rapidly at the extreme end: the parasite narrowed rapidly anteriorly. The body was alveolar-looking and deep blue, being of the same tint 426 J. B. CLELAND AND T. H. JOHNSTON. as the intracorpuscular bodies which were also present. The micronucleus was prominent near the posterior end: the undulating membrane was just recognisable with a short flagellum anteriorly. Another trypanosome was paler and less broad. One of the intracorpuscular forms had a definite deeply-stained micronucleus. Short filarise were present in one of these birds, but halteridia were not detected, though found in another specimen. In another bird, obtained in March at Hidsvold, a few free trypanosomes and intracorpuscular bodies were found. The trypanosomes were of the half-broad and narrow types with well-marked undulating membranes and moder- ately short flagella. The posterior end in one was shortly beaked. A few deep blue granules were seen in the proto- plasm of a narrow form. Some of the large intracorpuscular forms showed a deeper blue outer zone and a central paler area in the protoplasm, within which was the macronucleus. Short filarise were also present. In a fourth bird shot in October at Hidsvold, besides a few halteridia, intracorpuscular trypanosomes were also present. In one pale form, a few fine deep blue granules were present in the protoplasm. One free body was seen somewhat resembling a broad trypanosome without undu- lating membrane or flagellum ; its body was pale blue and vacuolated with purplish nuclear fragments near the centre and at one end a broad deep purple dot (micronucleus). Free and Intracorpuscular Trypanosomes of Oriolus sagittarius (M. 850). Free trypanosomes were found in a bird of this species shot at EKidsvold in January, and intra- corpuscular forms in the same bird and also in two obtained in April and May. The free trypanosomes were deep blue and very narrow; they showed a central macronucleus and a marked micronucleus near the posterior end: a narrow THE HAEMATOZOA OF AUSTRALIAN BIRDS. Ai undulating membrane and a short free flagellum were also present. The intracorpuscular phase in this bird occurred as deep blue spherical bodies embayed in the nuclei of red cells. The protoplasm was finely granular or alveolar with an occasional small vacuole: the macronucleus appeared as a pale purplish-red central mass: in one speci- men, the macronucleus appeared as a purplish mass at the side of the parasite, whilst near the centre, in a clear ring, the micronucleus was distinct as a deep purple dot. The nucleus of the host ceil was stretched round the parasite, extending from half way to beyond this. The protoplasm of the host cell could be traced beyond the parasite and host nucleus as a faint rim. Occasionally an earlier phase or a male form of intracorpuscular body was seen embayed similarly in a nucleus; its tint was a pale blue witha pale purplish central mass. In the April bird a single intracorpuscular body was seen. Halteridia were present also in this bird and in the January one, but were not seen in the May specimen. Intracorpuscular Trypanosomes of Sphecotheres mawil- laris (M. 852). In two birds shot in April, a few typical intracorpuscular bodies, like those found in Oriolus, were seen. Micronuclei were not noticed. Intracorpuscular Trypanosomes of Corcorax melano- rhampus (M. 883). In two specimens obtained at Eidsvold, Q., in April, a few typical intracorpuscular trypanosomes without centrosomes were seen, also one doubtful injured free trypanosome. Filariz were present in both of these. - PECULIAR BODIES, FREE AND IN THE LEUCOCYTES, IN THE BLOOD OF Micreeca fascinans. In the large mononuclear cells of a specimen of this bird obtained in May, in which halteridia but no intracorpuscular trypanosomes were present, some small rounded bodies were seen. Four cells were found thus affected in a few 498 J. B. CLELAND AND T. H. JOHNSTON. minutes search; the bodies lay in the protoplasm, some- times over the nucleus, and were from 3 to 9 in number. They were small (about the size of human blood-platelets), - rounded, and seemed to lie in small vacuoles. They stained reddish with Giemsa, and, in favourable specimens, the staining showed about 7 chromatic dots arranged in a ring with aclear space between the ring and the host protoplasm. In another bird obtained in April, several small purple bodies, perhaps a further stage of the above, were seen in a mononuclear cell. A larger phase, with bodies bluer, was also seen, and groups of considerably larger free spherical bodies of a pale bluish tint with a deep blue thickened edge round one half were fairly numerous. The last were quite possibly artefacts derived from the injured nuclei of red cells, though we have not seen the same appearance before. The blood films containing these various bodies were rather poor and the parasitic nature of the bodies is ques- tionable. We record what we have seen, however, so that other investigators may be on the lookout for similar appearances in other specimens of this bird. Bopiss (DEGENERATED RED CORPUSCLES) FROM A GALAH. | In a galah, Cacatua roseicapilla, which died in a Sydney shop in April from a peculiar nervous affection to which these birds are subject, some peculiar bodies were found in the blood. The bodies, which were about as long as but considerably narrower than the host red-cells, had elon- gated somewhat pointed ends and were spindle-shaped. Their protoplasm was bluish and somewhat granular, and was occupied by one to three rounded spherical bodies, showing in a clear area reddish chromatin masses. What appeared to be a larger form was also noticed; this was oval, the protoplasm was reduced toa peripheral ring and ~ THE HAEMATOZOA OF AUSTRALIAN BIRDS. 429 the centre was occupied by a large spherical pinkish body showing scattered chromatic granules. A further examination revealed the presence of other forms of these bodies which seemed to link them up with degenerated forms of red cells, in which the nuclei became separated into spherical portions and gradually degenerated. At first sight the bodies suggested a parasitic origin. SPORES OF A MOULD MISTAKEN FOR PARASITES. In the Second Report of the Wellcome Research Labora- tories at Khartoum appears in a coloured plate (Plate XXI, b.c.) a representation of elongated bodies supposed to have been found in the blood of a guinea-fowl, and these are referred to in the text (p. 196). The bodies are elongated and divided into four or more parts by partitions. On several occasions we have noted bodies identical with these while examining dried films of blood from birds, notably so in that of a Roller Bird (Eurystomus pacificus, M. 381). Their true nature was not realized until many months afterwards, when one of us was examining a small specimen of liquid blood forwarded in a bottle from a horse. This had become slightly mouldy, and on staining films, bodies indis- tinguishable from those mentioned above were numerous. The mould would seem to be a species of Fusisporium, a not uncommon saprophyte, and finding the spores in dried slides of blood may be easily accounted for either by their entanglement in the blood from the surroundings when the film was made or by the occurrence of mould in the sur- roundings of the film while stowed away. Microfilarie from Australian Birds. Filarial embryos have been detected in films from the following additional birds:—(1) Phalacrocorax melano- leucus; (2) Accipiter cirrhocephalus; (3) Glossopsittacus pusillus; (4) Podargus strigoides; (5) Hurystomus pacifi- cus; (6) Psphodes crepitans; (7) Artamus leucogaster; (8) a 430 J. B. CLELAND AND T. H. JOHNSTON, \ Artamus tenebrosus; (9) Cracticus nigrigularis; (10) Cracticus destructor; (11) Pardalotus melanocephalus ; (12) Myzomela sanguineolenta; (13) Plectorhampus lanceo- latus; (14) Stigmatops ocularis ; (15) Ptilotis fusea; (16) Myzantha garrula; (17) Entomyza cyanotis; (18) Oriolus sagittarius; (19) Corvus coronoides; (20) Struthidea cinerea; (21) Corcorax melanorhampus. (1) Microfilaria sp. from the Little Cormorant, Phalacro- corax melanoleucus, Vieill. (Hawkesbury River, N.S.W. Nov. 1910). These embryos were rather long, stout forms reaching from 116 to 140 ~in length by about 6pin width. The anterior end was bluntly rounded and of about the same diameter as the main portion of the worm. The posterior region tapered somewhat to end in a broadly rounded extremity. Faint transverse striations were recognised. The various breaks were situated as indicated. (Figs. 60, 61). (2) Microfilaria sp. from the Sparrow Hawk, Accipiter cirrhocephalus, Vieill. (Dr. Bancroft, Eidsvold, Q., June 1911). These parasites were relatively long (100 to 130) and thin, possessing a uniform breadth of 3°3 », excepting at the posterior end which tapered somewhat to terminate in a bluntly rounded tail. The ‘“‘spots’’ were situated at about 36, 74 and 94 per cent. of the body length distant from the head end. (Figs. 65, 66.) (3) Microfilaria sp. from the Little Lorikeet, Glossopsit- tacus pusillus, Shaw. (Dr. Bancroft, Hidsvold, Q., June 1911; L. Harrison, Gladstone, Q., Oct. 1910). In a blood film made from this host by Dr. Bancroft, there were abundant embryos, but they did not take up the stain satisfactorily. They were fairly short (66 to 75, long), | THE HAEMATOZOA OF AUSTRALIAN BIRDS. 431 the anterior region being a little wider (4) than the remaining portion, which gradually tapered to end in a sharply-pointed tail. In some specimens there was also a narrowing anteriorly, the rounded head end being not quite as wide as the succeeding portion. No distinct “‘spots”’ were recognisable, nor were annulations detected. The parasites present in a film made by Mr. Launcelot Harrison from a specimen shot near Gladstone stained rather better. They were slightly longer (68 to 100) and showed the presence of annulations. The anterior clear area was larger than that seen in the Burnett River speci- mens. The forms from both districts were of the same shape and probably belong to the same species of nematode. The spots were situated at about 25 to 28, 34 to 38, and 80 per cent. of the body length respectively. (Figs. 38, 39.) (4) Microfilaria sp. from the Frogmouth, Podargus stri- goides, Lath. (Dr. Bancroft, Eidsvold, Dec. 1910). Length 90 to 100 », breadth about 5p. The parasites were relatively short and thick, with a rounded anterior end anda short rapidly-tapering tail. Delicate transverse markings were present. The spots lay at about 27, 53 and 80 per cent. of the body length distant from the head end. (Figs. 53, 54). (5) Microfilaria sp. from the Roller, Eurystomus pacificus, Lath. (Dr. Bancroft, Hidsvold, Dec. 1910). Length 130 +, breadth 3°5 ». The head end was slightly rounded, the posterior end tapering toa fine point. The specimens did not allow of further examination. (Fig. 59.) (6) Microfilaria sp. from the Coachwhip, Psophodes crepi- tans, Vig. and Horsf. (Dr. Bancroft, Hidsvold, April 1911). 3 Length 200 p, breadth 5p. Very few specimens of this large Microfilaria were detected. The worms stained fairly 432 J. B. CLELAND AND T. H. JOHNSTON. evenly throughout. The extremities were almost alike, both being broadly rounded. In afew embryos, the tail end was slightly narrower than the rest of the body. (Figs. 55, 56.) | (7) Microfilaria sp. from the White-rumped Wood-swallow, Artamusleucogaster,Valenc. (Dr. Bancroft, Hidsvold, April 1911.) Length 90 to 120 4, breadth 4. Hach end was bluntly rounded, the tail tapering slightly. Annulations were readily recognisable. The nerve ring lay in the anterior sixth and the excretory spot in the fourth sixth of the body. (Figs. 50, 51.) (8) Microfilaria sp. from the Wood-swallow, Artamus tenebrosa, Lath. (Dr. Bancroft, Hidsvold, Febr. 1911). Length 120 », breadth 5. Very few parasites were detected. The head end was somewhat truncate, the tail end gradually tapering to terminate bluntly. Transverse strie were not recognised (figs. 72,73). This form is prob- ably specifically identical with that found in Artamus leucogaster. (9) and (10) Microfilaria sp. from the Butcher Birds Crac- ticus nigrigularis, Gould (L. Harrison, Gladstone, Oct. 1910), and C. destructor, Temm. (Dr. Bancroft, EHids- vold, April 1911). The two above mentioned species of Cracticus were found to be parasitised by a short thick microfilaria possessing distinct annulations. Hach extremity was bluntly rounded, the tail being only slightly narrower than the head in most of the specimens seen. In a few (from C. nigrigularis) the tail was rather more pointed. The length of the embryo varied from 80 to 110, the breadth being from 5to6p. A few smaller forms of 58 » by 2°5 pb possessing a somewhat pointed tail were seen in the film from C. nigrigularis. The THE HAEMATOZOA OF AUSTRALIAN BIRDS. 433 various spots were not distinctly recognisable in most specimens, though in some from the latter host their loca- tion appeared to be at about 30, 70 and 90 percentage of the body 20g distant from the head end. (Figs. 52, 57, 58.) | (11) Microfilaria sp. from a Pardalote, Pardalotus melano- cephalus, Gould. (Dr. Bancroft, Hidsvold, April 1911.) Length 90 to 1204, breadth 5°>. This parasite was found in only one out of many birds of this species examined by us. They were rather long and of an almost uniform breadth, the tail end being only slightly narrowed. Wach extremity was broadly rounded. The “‘spots’’? were at about 33, 60, and 90 per cent. of the body length. (Figs. 62, 63.) (12) Microfilaria sp. from the Blood Bird, Myzomela san- guineolenta, Lath. (Dr. Bancroft, Hidsvold, June 1911.) Vilarial embryos were detected in films from one out of four forwarded recently by Dr. Bancroft. The same film contained, in addition, both halteridia and intracorpuscular trypanosomes. ‘The filariz were relatively extremely long and delicate, measuring 270, or even more, in length, while the breadth only reached 1°54. The width was uniform. Hach end was bluntly rounded. The spots were situated as indicated in fig. 75. Dery TV, a OURNAL AN D PROCEEDIN GS | ROYAL SOCIETY a es NEW SOUTH WALES, i “PART IV., (pp. 445-555). ig fut Conrarnine PAPERS READ IN DECEMBER. WITH EIGHT PLATES. — _ Plates XXXIV, EXXV, eben XXXVii, XXXVill, XXXixX, KL, XLi. ) - Also with Abstract of Preceedinae: ; Title Page, List of - Publications, eae List of Members etc., and Index. ; SYDNEY: a! SHED BY THE SOCIETY, 5 ELIZABETH STREET NORTH, ‘SYDNEY.. / LONDON AGENTS: eee GEORGE ROBERTSON & Co., PROPRIETARY LIMITED, 17 WARWICK SQUARE, PATERNOSTER Row, Lonpon, E.C. , 1912. ee F. WHITE Typ., 344 Kent Street Sydney, on) pe = » co GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 445 THE GEOLOGY AND PETROGRAPHY OF THE PROSPHOT INTRUSION. By H. STANLEY JEVONS, M.A., B.Sc., F.G.S., H. I. JENSEN, D.Sc, T. GRIFFITH TAYLOR, B.A., B.Sc, and C. A. SUSSMILCH, F.G.S. (With Plates XXXIV -XXXIX.] ae. “a aaa ape [Read before the Royal Society of N. 8. Wales, December 6, 1911. | Part I. General Geology and Shape of the Mass. By T. Grirritra Taytor and H. Srantey JEVons. 1. Introduction. , 2. Bibliography. 3. General description of the mass. i. Shape of surface exposure. ii. General idea of shape. iii, General nature of the rock. iv. Exposures. | . Shape and thickness of the mass. . Manner and mechanics of intrusion. . Age of the intruded mass. 7. Depth of the intrusion, oO OF Part II. Petrography of the main mass and evidence of differentiation. By H. I. Jensen and H. Srantey Jevons. 8. General Petrology of the mass. 9. Systematic descriptions of selected specimens. i. Reservoir Quarry. } | ii, Emu Quarry. — ui. Other parts of the mass. 10. Characters of the original Minerals. i. Felspars. . , ii. Pyroxenes. ili, Other minerals. eon alt foi tdsx ay C 1—Dec. 6, 1911. ey NOV 7 1913 | (ager = \\\\ ; Vational Muse> at eee a. ee ee 446 H. 8. JEVONS, H, I. JENSEN, T. G. TAYLOR AND C. A. SUSSMILOH. 11. Characters of the Secondary Minerals. 12. Origin of the Analcite. 13. Consideration of the Analyses. (Analyses stated in full here, only the more important constituents having been stated under the descrip- tion of rocks.) 14. Nomenclature of the Rocks, (1) on the old, and (2) on the American quantitative systems. 15. Variations of Composition in the main mass. Distribu- tion of minerals and space relations of the resulting rocks. (Tables showing mineral composition of typical specimens. ) 16. Metamorphism and assimilation of the country rock. Part III. Segregation Veins. By OC. A. Sussmitcn and H. Sraniey Jrvons. 17. Distribution of the Segregation Veins in the mass. 18. Megascopic characters and relations of the rocks compos- ing the veins. 19. Micrographic description of the pegmatites and aplites. Appendices. I. Determination of the mode. II. Restoration of the original mineral composition. I. General Geology and Shape of the Mass. By T. GRIFFITH TAYLOR and H. STANLEY JEVONS. 1. Introduction. In the midst ofa gently undulating well wooded country, composed of Triassic (Wianamatta) shales, and almost at the centre of the great Permo-Carboniferous and Triassic basin of New South Wales, there occurs a massive intrusion of essexite (or dolerite) which displays many features of extreme interest, and which has been so well exposed by quarrying operations that it seems to merit a detailed description. The mass forms a conspicuous elevation— GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 447 named Prospect Hill—rising about 200 feet above the level of the surrounding country, and flanked on the west by the Prospect Reservoir, which conserves the water supply of Sydney. The hill covers an area of about 700 acres, and is situated immediately to the south of the main Western Road, some 18 miles from Sydney. It is accessible from Toongabbie station on the Main Western Railway, which lies nearly three miles to the north. The geological sketch map of the country in the vicinity of Sydney, published by the Mines Department of New South Wales, indicates the situation of the mass, and its relation to the neighbouring dykes and necks which are composed of similar basic rocks. 2. Bibliography. Owing to the position of Prospect Hill on the once much travelled main western road, we find references to it, and brief accounts of its geology, very early in the history of the State. Since the large quarries were opened, Prospect has been a favourite haunt of geologists, yet no systematic description of the whole mass of the eruptive rock has been attempted hitherto. The following is a list of the more important works containing notices or brief descriptions of the igneous mass at Prospect :— P. Lesson—Voyage autour du monde, Paris, 1826; vol. i, p. 328. M. Lesson made a journey to the Blue Mountains, and remarked ‘‘. . ce fait curieux d’une colline élevée, entiére- ment de dolérite, dont le pied est enveloppé de gres.”’ J.D. Dana—Report of United States Exploring Expedition of 1840. In 1840 Dana spent some months in New South Wales, and made some very interesting investigations into its geology. The results of his work are embodied in the very rare volume giving an account of the above expedition. 448 H. 8. JEVONS, H.I, JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. Under the heading ‘‘ Basaltic and Allied Rocks,”’ (Litho- logical characters, page 497) he distinguished ten varieties of which the four following are found at Prospect :— Variety (a). Tough compact black rock, no traces of crystallisation, .... afew grains of chrysolite may with difficulty be distinguished. Variety (e). A dark bluish rock, finely porphyritic with small points (not tables) of felspar. Variety (g). A porphyritic basalt in which augite and felspar are both distinct and some of the crystals of augite are a quarter of an inch long. Variety (h). A felspathic rock consisting almost purely of thin tables of felspar aggregated into a moder- ately compact rock, with occasional geodes of smaller felspar crystals. Some small specks of augite appear disseminated through it and more resemble green earth than augite. Further he madea very interesting note:—“‘At Prospect. Hill the compact black basalt changes to a compact rock with disseminated points of felspar; .next to porphyritic basalt with distinct crystals of both augite and felspar, and next to the felspar rock (h), in which augite is almost wholly wanting.” Dana also gives asketch of columnar structure occurring at Prospect, and explains a peculiar type of decomposition, which will be referred to in a later section. Rev. W. B. Clarke—Report on the Southern Gold Fields. of New South Wales, 1860. Clarke decided that Prospect Hill was composed of ‘*magnetic diorite . . . . which is probably the summit of a concealed mass, submerged during the Carboniferous. | period;’’ andassigned the basaltic border variety to a much | later intrusion. These views have not been upheld by sub- sequent investigation under more favourable circumstances. GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 449 T. W. Hdgeworth David—Proc. Roy. Soc., New South Wales, 1896. In his Presidential Address, Prof. David corrects Olarke’s errors, and shows that ‘‘the dolerite graduates into the basalt,’’ and that ‘‘both have intruded the overlying Wiana- matta shales.’’ There is also some description of the main type of rock, and its decomposition. M. Morrison—Records of the Geological Survey of New South Wales, Vol. vil, pt. 4 (1904), p. 241. A list of the dykes, necks and other masses of igneous rock in the neighbourhood of Sydney, with a detailed account of several of the less known localities. A list of literature on the subject is given, which was of service in compiling the present bibliography. 3. General Description of the Mass. Prospect Hill rises sharply from nearly level country on its western, southern and eastern faces, but its northern slope is more gradual. As regards shape it may be com- pared in plan to a rude shark-hook, the shank lying to the east, the convex bend to the south. The depression in the centre is drained northwards by a small creek which ultimately finds its way into the Parramatta River. The accompanying map (Plate XXXIV), will convey a more accurate idea of the shape of the surface outcrop of the igneous rock, and indicates by means of rough contour- lines the elevation of the surface. The whole mass is nearly two miles long by one mile wide; and portions lying to the east and south—the ‘“‘shank’’ and ‘“‘bend of the hook’’—are somewhat higher than the western part— the “* barb.”’ Inspection of the map shows that there is an isolated area of Wianamatta shale surrounded by exposures of the igneous rock. Numerous sections show that nowhere in this patch is the shale more than a few feet thick, and 450 H. 8S. JEVONS, H. I. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. that the igneous rock is everywhere continuous beneath it. Moreover, it is thickest about the centre and thins out in every direction against the surface of the intrusive, not excepting the direction of the confined valley by which the creek leaves the mass. Here for a short distance there is no actual shale to be found, though there is every reason to suppose that a connecting neck of shale may have existed until comparatively recent times. On its outer edges the intrusive mass abuts nearly vertically against the shale, as will be shown later. In shape, therefore, the igneous mass is a rather elongated irregular oval, its upper surface being depressed in the centre. In composition the main mass of the igneous rock resembles the olivine-gabbros and dolerites (diabases), though, having only about forty-two per cent. of silica, it is more basic than their average by about four or five per cent. Its composition and association show, however, that, though poor in alkalies, it is in reality an essexite, similar to the essexites of Brandberg and Solvsberg. The essential constituents of the main Prospect rock are a violet-brown titaniferous-augite and an acid labradorite in about equal proportions (roughly 36% each), olivine (about. 10%), ilmenite and magnetite (about 137); and as acces- gsories, sometimes increasing in importance, occur biotite and apatite. The outer envelope of the intrusive mass is a very dark compact grey rock, having the appearance and microscopic characters of basalt. Going inwards from the edge it passes gradually into a rock having the appearance of a very fine-grained dolerite, and the grainsize continu- ally increases until it becomes fairly uniform in the central parts of the mass. Here the rock, when fresh, has a speckled black and white appearance, the individual crystals of augite and felspar being easily visible in the hand speci- men; or, where partly decomposed, it has the chloritic green colour so well known in weathered dolerites. Im- GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 451 mense veins of lighter coloured rock, reaching four feet thick, nearly white where fresh, but generally light greyish- green from decomposition, traverse the main mass, and catch the eye upon the walls of the quarries. These are aplitic veins, the final product of differentiation resulting from the cooling of the mass. Less obvious, but equally interesting, evidence of difierentiation by other processes preceding the aplitic segregation has been obtained by Messrs. Jensen and Jevons in the course of their study of the proportional distribution of the minerals in different parts of the mass, and wil! be stated in the second part of this paper. An interesting series of decomposed products is found, and analcite occurs in such manner as makes it necessary to discuss the possibility of its being of primary origin. Hixposures of the igneous rock are numerous and good. By far the best section is given by the Old or Reservoir Quarry, situated on the westernmost slope of Prospect Hill, close to the eastern end of the great dam for which it provided the massive stone facings. As shown by the map (Plate XXXIV), a level floor has been cut nearly one hundred yards back into the hill, thus exposing a steep freshly cut face of rock three hundred yards long, by from seventy to eighty feet in height. A sketch of part of its face is given in the transparent sheet overlying Plate XXXV, which is a photograph of a part of its face. Other exposures on the W. and S.W. of the mass are afforded by some shallow workings a few yards S.H. of the south end of the Reservoir Quarry, and by Booth’s Quarry a little further to the S.E. These afford excellent sections of the outer envelope of the intrusion and of the overlying shales. A little to the north of the centre of the mass, lies the Emu Quarry (so-called because it has been for some years worked by the Emu Plains Stone and Gravel Company). 452 H.S. JEVONS, H.I. JENSEN, T G. TAYLOR AND C. A. SUSSMILCH. The foregoing are the exposures which have provided most of the material, but there area few other shallow workings, and numerous natural crags and outcrops of weathered rock, especially on the eastern ridge or “‘shank”’ of the hill. Our work has been hampered for want of exposures only in connection with determining the outer boundary of the mass, and in trying definitely to decide whether the inner area of shale is connected with the shale outside along the creek or not. 4. Shape and Thickness of the Mass. The shape of the Prospect intrusion can be inferred from inspection of the map in conjunction with the cross section which accompanies it, and it is found to be peculiar and difficult to explain. The line of section shown upon the map (Plate XXXIV) passes nearly east and west through the centre of the mass, and was chosen as being that along which the exposures gave the most precise information. In the middle of the intrusion is seen a thin layer of Wianamatta shale resting upon the outer layer of compact igneous rock, which we propose to call pallio-essexite,' which in turn rests upon the main mass of essexite. (Figs. 1-3). Both to east and west the junction of the intrusive rock with the shale rises, until first the pallio-essexite is un_ covered, and then the essexite. Unfortunately no section ’ The prefix pallio- has been adopted by Mr. Jevons as part of his systematic nomenclature of igneous rocks, to denote the compact envelope of rapidly cooled rock which encioses every intrusion, from pallium, a mantle or cloak. We see no reason why the use of this term should be confined to a particular system of nomenclature, and believe that it could be compounded with names at present in use with much advantage in clearness and brevity of expression. Thus pallio-granite would signify the rock, usually a quartz-porphyry, which occurs on the border of a granite mass a little way within the contact. Further from the junction the rock assumes the character of a granite-porphyry, and it might be denoted sub-pallio-granite. It is also convenient to use the word palliwm to denote the compact outer envelope of a mass without special reference to the kind of rock which composes it. GEOLOGY AND PETROGRAPHY OF THE PRUSPECT INTRUSION. 453 showing the junction of the igneous rock with the shale on the periphery of the mass is anywhere exposed, hence only hypotheses can be advanced concerning its exact position, or angle of dip, at either end of the section. At the west end there is, however, some evidence, for shale was found in situ at the top of the bank of the cutting. Furthermore, one of us was assured by the Waterworks Kngineer, Mr. Jacob, that the shaft which is on the line of the section AB was sunk entirely through Shale. Asan exposure of pallio- essexite occurs something less than 100 yards to the east of where the shale is found in situ, and as it is found from this point to follow the slope of the hill upwards until it gives place to the essexite, it seems rational to suppose that here the envelope of compact rock is dipping outwards, 7.e. west, and at an angle a little steeper than the slope of the hill. If this be so, the junction with the shales must dip more and more steeply as it descends or else it would not avoid the shaft which is 50 feet deep. Probably the peri- phery of the mass has the vertical section shown by. the hypothetical broken lines at the western end of the section. At the eastern end of the section, although there are a few exposures of pallio-essexite on the outer slope of the hill, there is not such clear evidence of the direction of the junction. The position of the outer junction is difficult to determine on almost every side of the mass; but we have been to some extent guided in mapping by a rather sudden change of suriace gradient from a steeper slope above to one more gradual below, which probably indicates roughly the change from harder to softer rock. At first considerable use was made of the change from the red soil of the igneous rock to the bufi-coloured soil of the shales. This change is empha- sised by the occurrence where the soils mix of peculiarly shaped calcareous nodules varying in size from that of a 454 H. 8. JEVONS, H. I. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. pea to that of a large compound potato, which latter they resemble in shape. Finding however, that the red soil could be traced in some directions right down to the bed of the creek, draining the valley on that side, we were at a loss to know how much to allow for surface creep, and came to regard the change of slope already mentioned as more trustworthy, except on the S.W. of the hill where the proximity of the Prospect Oreek has led to considerable denudation. ; The original spacial form of the intrusive mass may be inferred from the map and section. The mass was roughly oval in its horizontal extension. Its upper surface was depressed in the centre, and rose to a ridge all round, or nearly all round. Outside the ridge its surface probably fell everywhere steeply outwards. The under surface is nowhere exposed, and its shape is wholly a matter of con- jecture. That the intrusive mass has roughly the form of a Sheet seems probable, partly because of the well known tendency of basic magmas to lift strata bodily and spread out in horizontal sheets, but still more because the shales of the overlying central patch are almost everywhere practically horizontal, just as are the undisturbed shales throughout the district. Only in one place has a dip of as much as 10° been observed (in Booth’s Quarry), and here the dip is nearly parallel to the surface of the mass. It is impossible that the cavity formed by the mere lifting of a block of strata, without bending or tilting, should have any other shape than that of a sheet of uniform thickness, though if the under surface of the block be not flat, it necessarily cannot be a flat sheet. The best conclusion from the available evidence seems to be that the Prospect mass was originally a sheet, shaped like a round bottomed oval dish with the convexity downwards. As regards the thickness of the sheet there is no direct — evidence; and the unfortunate scarcity of fossils in the GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION, 455 Wianamatta shales precludes the posibility of using paleeon- tological zones to determine the horizon of the central area of shales. Indirect evidence, however, is available. The nearness of the outcrop of the underlying Hawkesbury Sandstone, located about five miles both to east and south, makes it almost certain that the Wianamatta shales which have an extremely small westward and north- westward dip, cannot be here more than at most 300 or 400 feet thick, whilst they may be only 200 feet thick. If the intrusive sheet were more than 300 or 400 feet thick it must therefore have lifted Hawkesbury Sandstone; but there is not the slightest trace of any sandstone beneath the shale of the central area, or even of the shale being of a sandy character. Remembering that the lower surface of the central patch of shale stands about 50 feet above the level of the surrounding country, we thus have 450 feet as the absolute maximum which we can allow for the thickness of the sheet; but a more probable figure would seem to be about 300 feet. There is nothing in the character of the rock exposed on the floor of the Reservoir Quarry, which penetrates deeper into the mass than any other exposure, which would lead one to suppose that this latter figure is an under estimate. The same quarry provides us with a minimum figure of about 150 feet for the thickness of the sheet, for at its northern end it extends at least 80 or 90 feet below the cooling surface, and there is no sign of the grainsize beginning to get finer again at the bottom. Whether the intrusion more probably took place through a fissure or a pipe we cannot say, for both these forms of conduit are common in the district. The position of the supply pipe or fissure is also uncertain. It may be under the south-east portion of the hill, because this is the most elevated and massive, or it may more probably, as will be shown later, be beneath the central area of shale. 456 4H. S.JEVONS, H. I. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. 5. Manner and Mechanics of Intrusion. An attempt to elucidate the manner in which the intru- sion took place may not be without interest. The locality is near the centre of the great Permo-Carboniferous basin, and the magma may be presumed to have been forced upwards through about 13,000 feet of marine and coal measures, and about 2,000 feet of Triassic strata, by an earth movement which was probably continuing the warp- ing of the basin, and produced a widespread igneous activity, which will be referred to again. Whether the magma ascended by a fissure or a pipe, soon after leaving the Hawkesbury Sandstone it reached such a level in the shales that the weight of the superincumbent strata became less than the upward lift of the magma. The latter then tended to spread laterally. For some reason, however, it did not follow the horizontal bedding planes, as in an ordinary sill or lacolite, but spread in a conical layer, liit- ing, through a height of 300 feet or more, an oval portion of shale with a rather rounded shallow conical base convex downwards, 700 acres (280 hectares) in area. A question difficult to settle is whether the overlying shale was dislocated and faulted up as shown in fig. 1, the corners being rounded off by assimilation or engulfing of of fragments, as indicated by the broken line, or whether the strata were sharply bent as shown in fig. 2. In favour of the hypothesis of bending is the fact that on all sides, wherever the pallio-essexite is visible, it dips outwards gradually. This is particularly noticeable on the northern slope of the mass, and to account for its development by assimilation from a vertical wall, as in fig. 1, would postu- late a greater amount of assimilation than petrographical evidence seems to admit. On the other hand, against the hypothesis of bending is the fact that no exposure of shales with an outward dip has been found. It is true that with Wianamatta Basalt Eraded Shale Dalemrte Surface, s 4 VETERAN HALL , CREYSTANES A | ' WIANAMATTA SHALE Eroded Surface. oo Hall. SAY Greystanes. (Pallio - Essexite).. Se SSS a ee \ ly NB ope \ WIANAMATTA SHALE Eroded Surface. | : 4 j BASALT. Z all Veteran Hall. | (Pallio - Essexite). = Greystanes, but that in passing from specimen P to the Survey specimen, when the felspar changes from 50 to 563 per cent., the ratio of ores to augite is nearly constant, thus perhaps pointing to the dilution theory as acting between these two specimens. Changes in the proportion of the iron ores are not found only in a vertical direction, or from the exterior of the mass inwards, but also in an apparently irregular manner, The best example of this is to be found in the Reservoir Quarry, a little to the south-east of the middle of the face. In the immediate neighbourhood of the great segregation veins, and particularly in their pegmatitic portions, the ilmenite crystals attain great.size and generally lie nearly horizontally. They form a striking feature in the hand- specimens, appearing aS very thin hexagonal tables or 520 H.S. JEVONS, H. I. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. leaves with almost the lustre of biotite and often nearly 3cm. (1 inch) in diameter. Other bands or patches rich in ilmenite have been found in other parts of the mass. Little can be said with certainty as to the distribution of apatite, because it is almost impossible to estimate its quantity with any approach to the truth by the Rosiwal method unless unusually abundant. The impression gained from all the slides made, however, isthat there is a tendency for apatite to be more abundant in the immediate neigh- bourhood of segregation veins, whilst there is undoubtedly a good deal of it in those veins themselves. Of the speci- mens represented in the table, P comes from close beside an aplitic vein, the Survey specimen (column V) probably comes from near one, and column VI is the aplite, and all have more apatite than specimen I; but so has a specimen of the pallio-essexite also (column IT). The main features of the distribution of the minerals as described above may be summarised thus: (1) the pallio- essexite is richerin olivine and biotite than the main rock, and its plagioclase is a little more acid; (2) a concentration of felspar occurs in a layer extending horizontally probably throughout the mass, and reaching downwards from a depth of 4 or 5 metres below the junction with the shales to 17 metres, and always parallel with the junction; (3) the irregular distribution of the iron ores, which tend, however, to be much more abundant in the main rock than in the pallio-essexite, especially than in the inner zone of the latter (as represented by specimen ©); and(4) the uniformity in composition of the main rock below the segregation veins so far down as it is anywhere visible. The principal changes in composition have been found to be ina vertical direction; as to whether there is any change horizontally on a large scale in the mass as a whole, the exposures do not warrant any certain conclusion. Probably the pallio- GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 521] essexite on the sides of the mass has the same composition as on the top, and if so there must be horizontally the same change on going inwards to the main rock as was found in going vertically downwards; but there is nowhere any indication of further horizontal change. 16. Metamorphism and Assimilation of the Country Rock. The only kind of country rock abutting on the intrusive rock at the present surface of the ground is the Wianamatta shales, which varies little in composition, except that occasional bands are more sandy and others more calcareous than the average. In no place is more than the very slightest alteration apparent. The shales have been con- siderably hardened, enabling them better to resist weather- ing, but in the hand-specimen no other change but the different fracture due to this hardening is visible. In thin section under the microscope, specimens of shale taken from close to the junction appear precisely the same as unaltered shale, so that the alteration which has taken place must be extremely slight, and be confined probably to a recrystallisation on an extremely minute scale. Optical investigation having given this negative result, the matter did not seem worth pursuing by chemical analysis. Melting up and assimilation of the country rock has undoubtedly occurred to some extent, though probably not on a large scale. Direct evidence is afforded by the occur- rence in a number of slides of the pallio-essexite of circular or oval patches which are nearly opaque or dark grey in colour, having a minutely granulated appearance; do not depolarise except weakly as a very fine mosaic under the high power; and whose edges are not defined, but shade away gradually into the surrounding fine-grained ground mass. These are unquestionably partially absorbed frag- ments of shale, which they closely resemble in every way under the microscope; but no special minerals are seen 522 H.S. JEVONS, H. I. JENSEN, T. G. TAYLOR AND OC. A. SUSSMILCH. around them, nor any unusual abundance of the ordinary minerals of the essexite. Hence we may assume that the portions of shale assimilated merely augmented the felspars of the magma and perhaps to some extent the augite, by supplying hypersthene molecules produced by the inter- action of quartz with olivine. A few rounded crystals of quartz have been found in the pallio-essexite, which are undoubtedly grains of sand derived from arenaceous bands in the shales. One of these which occurs in a section of specimen L is reproduced in fig. 1, Plate XXXIX. The quartz is all one crystal, but it has been much cracked, and chlorite has forced its way into the cracks. It is surrounded by a reaction rim of a very pale green or color- less fibrous mineral disposed in an irregularly radial manner, which may be either actinolite or simply a non-titaniferous augite. It is evidently formed by reaction of the quartz with the olivine molecules still in the magma, with the inclusion perhaps of some anorthite and wollastonite mole- cules. ‘The amphibole or pyroxene of this reaction rim is now a good deal chloritized. Indirect evidence of assimilation of the shales is perhaps to be found in the more acid character of the plagioclase of the outer envelope as compared with the rock of the main mass. Microscopic evidence alone suggested this comparative acidity, as the maximum extinction angles in Symmetrical sections of the plagioclase crystals were found to be lower in specimens coming from near the contact than in the specimens from the main mass. Subsequent calculation from analyses of the average compositions of the plagioclase of the typical specimens amply confirmed this view. In specimen B of the pallio-essexite the aver- age compositions of the plagioclase was Ab;Ans, in speci- men I of the main rock it was Ab,An,. That the more acid character of the felspars of the outer envelope is due to assimilation, and not to some kind of differentiation GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 523 cannot be absolutely affirmed; indeed it may be only partly due to assimilation and largely to the fact that the process of differentiation which produced the great segregation veins containing nearly pure albite, to be discussed in the succeeding part of this paper, impoverished the main rock near these veins (which is all that is accessible) in regard tothe albite component; so that the average composition of the plagioclase of the pallio-essexite would be only a little more acid than that of the original magma before intrusion, and that of the main rock distinctly more basic. Hence we may say that there is evidence of slight assimil- ation, but no more. Analyses of Prospect and other rocks. Table I. I. IT. IIT. IV. V. VI. VIL. (Prospect) 09 SiO, 4745 46°92 4541 43:06 41:05 47:90 47-00 mine oo 180 16°65" 1631) 12°27 16-55, «15-20 He,0 7 © 2°47 3°61 4-14 5°40 6°39 5°67 5°69 feO® has | 6-73 8°86 po Opa lel=2i6 8:10 6°85 MgO 5:00 7:43 0:27 5°49 6°38 4°44 8:76 CaO 8°87 BB oll 9°43 3°37- 10°96 9°35 §=12°60 Nias? ~ 2°97 2°99 3°38 3°12 2°43 3°23 1-45 K,O 0-99 1:24 0-64 EON 0:53 2:08 0:66 PLO: 0:19 8 0:32 0:19 0:32 trace nOO-12 9 99°98) 100-29 100°30 100;3)- 99°75 100-81 Table II. | ie II. Lies IV. V. VI. Vik SiO, 48 48 46 46 43 48 AT Al,O, 15 Lo= i 13 Wears oi Fe,O, 2°5 ed 43 0 6-7. Del at PeO* 15 ¥ 9 = 1 8 7 MgO 5 (= 7- 6 6- 4— 9 CaO 9 9— 10 10 tl— 9- hee Na,O 3:0 wae 319 Die 2°5 3:3 US K,O 1:0 Thee) if 1°] 15) 2:1 T TiO, 1°5 1:0 1:5 2°6 4:5 1:9 2:3 P,0, nt “2 2 3 2 3 trace * To the FeO are added MnO, NiO, and CoO. 524 H.S.JEVONS, H. I. JENSEN, T. G. TAYLOR AND C. A. SUSSMILOH. I. DoueriteE ; Scourie, Sutherlandshire, Scotland. J. J. H. Teall, anal., J. J. H. Teall, Q.J.G.S., xxi, (1885) p. 135. II. DoueritE (Diabase); Bochtenbeck, between Niedersfeld and Wiemeringhausen, Oberes Ruhrthal, Westfalen. III. Doxerite; Nant Llwyngwern, Berwyn Hills, North Wales. M. Dittrich, anal. Not previously published. IV. EssexitE; Prospect, probably Emu Quarry. J. C. H. Mingaye, anal. G. W. Card, desc., Records Geol. Surv. N.S.W., Vol. vit, part 3 (1903) p. 229. In addition 0:02 Cl, 0:26 S, 0:02 BaO, 0:05 V,0O,.. V. Essexite; Prospect, Specimen I, towards north end of Reser- voir Quarry. J. O.H. Mingaye, anal. In addition 0°35 §, 0:06 VO. VI. Essexire; Tofteholmen, Christiania Fiord, Norway. V. Schmelck, anal. W.C. Brogger, Erup.-gest. des Kristianiageb., Vol. 111, p. 83. VII. Essexite ; Solvsberg, Gran, near Christiania, Sarnstr and Schmelck anal. W.C. Brogger, Q.J.G.S., L. (1894) p. 19. Table III. VIII. IX. X. XI. XII” XN Seve (Prospect.) SiO, 48:22 45:74 43:39 4626 46°51 47:66 45:11 Al,O, 14°27 1482 16°67 13:36 15:27 14:36 242-438 Fe,O, 2°43 2°40 347 2°34 2°50 2°83 2°67 FeO* 9°23 7°52 8995) 10°66 9-00 8°44 9°62 MgO 6:24 6:98 7°30 8°87 8:40 8:19 /-— Tias CaO 8:45 10°81 oes) 9:18 9°12 9:36 10°61 Na,O 2°90 3°08 3°30 a27 3°12 3°51 3°05 K,O 1:93 290 2°17 1:23 Ll 1:54 1:01 H,O 1:94 2°94 2°96 2°23 1:43 0:37 0:94 CO, 0:15 1:50 0:39 0:06 0°61 Bs ine TiO, 2:79 2°80 2:20 1:78 2:20 3°83 2°34 iP @, 0°64 0:64 0:41 0:42 0°33 0:45 0-51 99°30 100-23 100:28 99:90 99:90 100°54 100-02 GEOLOGY AND PETROGRAPHY OF THE PKOSPECT INTRUSION. 529 Table IV. Void. IX, xX. XI, XY * exeElt, OXY. SiO, 49 46 45 48 48 48 46 PAO One SY sAl52 conzeex -or4 ieeaididiéeusct ‘hee Fe,0, 25 pes Gis 2 ee D- eal Oni FeO* 9_ 8 gee TS Me 9 goatee Tig MgO 6— i es 9 Bi 8 Lie Cad Bo abr sluhe 9 9 Gaia Monee. Tl Tig 0) ) DRE EARS) Oo mmo et) aR is eg 2 et sg oor rare eas) Ope t Sa aOlsl ag TiO, sageee oth! Wo. gti quplo)\ipig ilo seg inl ong P.O, 7 7 4 -4 3 ey 1D Des * To the FeO are added MnO, NiO, and CoO. VIII. CamptoniteE; Mount Ascutney, Vermont, U.S.A. W. F. Hildebrand, anal. R. A. Daly, B.U.S.G.S., 148, p. 70. In addition 0:04 BaO, 0:01 Cl, 0:05 F, 0°36 FeS,. TX. Moncuiquire; Rio do Ouro, Serra do Tingua, Brazil. P. - Jannasch, anal. Hunter and Rosenbusch, Tscher. Min. Pet. Mit., x1 (1890) p. 464. In addition 8 0:10. X. BasAtt, containing ANALCITE; Bondi, Sydney, N. 8. Wales. J.C. H. Mingaye, anal. G. W. Card, J.C. H. Mingaye, and H. P. White, Rec. Geol. Surv. N.S.W., Vol. vir, pt. 2, GHoO2) son oi) s In saddition VO, 0:01, SO, 0-19, Cl.0-02; BaO 0:02. XI. PALLIO-ESsEXITE; Prospect, specimen B, south end of Reser- voir Quarry, J.C. H. Mingaye, anal. In addition SO, 0:13, Ci 0:01, Cr,O3 0:02, BaO 0:05, V,O, 0:03. XII. Basatr; Camden Park, near Sydney, N.'S.W. J. C. H. Mingaye, anal. Mingaye and White, Rec. Geol. Surv., N.S.W., Vol. vu, pt. 3, (1903), p. 230. In addition V,O, 0:03, SO, O-11, Cl 0:04, Cr,O, 0°02, BaO 0:04. XIII. Basatr (Camptonose); Castelfullit, near Olot, Oatalonia, Spain. H,8. Washington, anal. and desc., Q.J.G.S., Vol. Lxull, (1907), p. 74. XIV. Basatt; Pinto Mountain, Uvalde County, Texas. W. F. Hildebrand, anal. W. Cross, B.V.S.G.S., 168, p. 61. In addition Cl 0:11, S 0:01, V,0, 0:04. H 1—Dec. 6, 1911, 526 4H. 8. JEVONS, H. I. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. III. The Segregation Veins. By OC. A. SUsSMILcH and H. STANLEY JEVONS. 17. Distribution of the Segregation Veins in the Mass. In petrological literature the term segregation vein has a generally understood but not very precise signification. It will be used here to mean all those rock masses which are distinct in composition from the main rock of the intrusion, tending to be more acid, and which in their origin are intimately connected with the later stages of cooling and crystallisation of the magma, whether occurring in sheets or irregular shapes, within or without the main mass. The term denotes the rocks commonly known as aplites and pegmatites, the former finer-grained, the latter coarser-grained than the main rock; but we extend it to rocks of this character in the widest sense—whether their grainsize differ much or little from that of the main mass, and whatever the composition of the latter. In the segregation veins at Prospect there occur both aplitic and pegmatitic rocks, and these only according to our definitions which will be explained later; but these distinct rocks are not generally confined to different veins, but are closely intermingled or associated in the same vein. In tracing the distribution of the segregation veins through the mass, therefore, no account need be taken of the rocks composing them. The only general feature we have observed regarding the distribution of the different types of rock is that the smaller veins (those up to about 10 cm. in thickness) appear to be more frequently composed of the aplite only, than of either the pegmatite only, or both rocks mixed. Both constituents of the segregation veins appear at a distance lighter in color than the main rock, whether fresh or weathered, the aplite rather more so than the pegmatite, and there is thus little difficulty in finding and following them over any available area of rock. The veins vary much in thickness, from 1 to 120 cm. | GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 927 The best exposure in which to study the segregation _ veins is undoubtedly the Reservoir Quarry. Here may be seen at a glance the two great segregation veins already mentioned above (see Plates XXXV. and XXXVI.). They lie about 4 m. (13 ft.) apart; and they run parallel in a remarkable degree with the junction surface of the pallio- essexite and with the shales, following even minor undu- lations of the junction, the uppermost at a depth of 13 m. (45 ft.) below it. Where the junction turns sharply upwards _and vanishes in the present ground surface, near the north- western end of the quarry, the great veins follow and also are lost by denudation; so that in the middle of the quarry the outcrops of these two veins upon the face are roughly horizontal, whilst in the north-western part of the quarry they dip to the south-east at 30° (see Plate XXXV). The true dip of these great segregation sheets in the southern half of the quarry may be ascertained by standing near the face of quarry and looking to the south east. On the southern wall of the quarry, although the rock is much decomposed, the segregation sheets are clearly seen, dip- ping at about 35° inwards, towards the face of the quarry (see Plate XXXVI). Their dip here is nearly east-north- east, that is, directly towards the centre of the southern part of the intrusion, as may be seen on consulting the plan. The reason why the outcrops of the veins on the face turn upwards and disappear in the northern half of the quarry, is that these sheets no longer dip at right angles to the face, but due east (magnetic). The sheets have in the southern pavement of the intrusion, a quaquaversal dip towards a centre of the intrusion. Bearing in mind the close conformity of the outcrops of the sheets upon the face with the overlying junction, it seems probable that the sheets were everywhere parallel to the junction, hence the upper surface of the intrusion near its periphery must have had a quaquaversal inward dip of about 35°; which 528 4H. S. JEVONS, H, I. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. is evidence of the existence of the peculiar rim to the oval dish-shaped sheet already mentioned in the first part of this paper. In the northern part of the Reservoir Quarry, the main rock is exposed well below the great segregation veins, and it is found to be comparatively free from segregation veins of any kind. A few thin veins are to be seen, gener- ally not exceeding 10 cm. in thickness, two or three of which are parallel with the two great veins, whilst most of them have no special orientation. There is no trace of any other great segregation veins comparable with the two just described. They would be easily seen even on the most weathered rock if they existed. Between the great segregation veins there are a few thin veins connecting them, running nearly at right angles. to them or more obliquely ; and these cross veins sometimes swell into irregular masses of aplitic and pegmatitic material. Above the great veins there are also numerous. smaller veins running in various directions. One of these,. averaging from 20 to 30 cm. in thickness, is larger than the rest; it branches off the upper great vein near the middle of the quarry face, runs upwards a little, and then continues. parallel with the junction of the shale, at a depth of 5 m. (16 ft.) below it. This vein finds its counterpart in a somewhat similar vein lying at the same depth in the Emu Quarry. The smaller veins are some of them parallel with the junction, and the rest run very roughly at right angles. to it. It is worthy of note that the segregation veins. never penetrate into the most compact part of the pallio- essexite, that is, within 2 m. (6 ft.) of the junction with the shale, and the few which are found in the sub-pallium to 4 m. from the junction are always thin. | The thickness of the two great segregation veins is. variable ; indeed they are not regular sheets like the very GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 529 thin veins, but from point to point are everywhere altern- ately swelling and thinning out again in an irregular manner. Inthe thinnest parts they are sometimes reduced to as little as 15 cm. in thickness, where largest they reach a width of 120 cm. Their average thickness is per- haps about 60:cm. In places, however, the veins swell up into oval or irregular shaped masses, from which one or more subsidiary veins often branch off. The largest of these (Fig. 4) is shown on Plate XXXV., near the letter H, and is described and figured in the next section. It is nearly 3 m. thick, and more than twice as long. Fig. 4.—Sketch of part of one of the large Segregation Veins. In the Hmu Quarry segregation veins are common in much the same degree as in the upper levels of rock exposed in the Reservoir Quarry, and the upper of the two great veins is exposed in the deeper part of the quarry at its north end, so there is evidence that they have a wide extension. Hxposures in other parts of the mass (e.g. Booth’s Quarry) show that segregation veins, chiefly aplitic, are widespread in the mass at a level immediately below the most compact pallio-essexite. Neither pegmatitic nor aplitic veins have been found penetrating and intruding the shales anywhere at Prospect. 18. Megascopic Characters and Relations of the Rocks Composing the Veins. The rocks fillmg the segregation veins vary both in composition and texture. As already stated they may be 530 4.8. JEVONS, H. 1. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. classed in two distinct groups: the pegmatitic which is coarser than the normal rock, and the aplitic which is of equal or finer grainsize. There are two kinds of pegmat- ites, and three kinds of aplites, distinguished from one another by their grainsize. All grade into one another, but the types named are the most abundant. The finer pegmatite has a variable grainsize, approximately 2°5 mm. and is thus but little coarser than the main rock. The coarser varies considerably in its grainsize, roughly from 5 to 10 mm., but individual crystals more than 30 mm. in length are not uncommon. Towards the southern end of the Reservoir Quarry the pegmatite of the great segre- gation veins contains abundant ilmenite in exceptionally large crystals. They are thin hexagonal flakes, sometimes skeleton-like, a deep rich brown in colour, with almost the splendent lustre of biotite, and commonly 3 or 4 cms. in diameter, though in one place they reach 10 cm. in greatest diameter. It is curious that they seem to stand roughly perpendicular to the edge of the vein. The finest-grained aplite is almost compact in appearance, its grainsize varying from 0°1 to 0°15 mm. In the medium variety the grainsize varies from 0°25 to 0°75 mm., and in the coarse aplite from 1 to 2mm. In different patches of the same kind of aplite, or from part to part of one patch, the grainsize may vary between the limits stated (which do not pretend to great accuracy); but the boundaries between aplites of different grainsize are always extremely sharp. The coarse aplite often has the same grainsize as the main rock of the intrusion, but is quite distinct both from it and from the fine-grained pegmatite in texture and composition. The most interesting feature of the segregation veins is the mutual relations of these different varieties of aplite and pegmatite when they occur side by side in the same GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 53] vein. When the two are present in the same vein the aplite always occurs in the middle of the vein with the pegmatite on either side. There are, of course, many small veins containing aplite only, and a few containing pegmatite only; but where the two are together there is always pegmatite on either side of the aplite, though there may be very much more on one side than the other. The pegmatite not infrequently appears to shade off gradually into the main rock, and it is never separated from it by a. quite sharply defined boundary, but its junction with the aplite it encloses is generally quite sharp. The relations of the pegmatite to the aplite, and of the different varieties of these rocks to one another, are never suggestive of the intrusion of a consolidated rock by a wholly or partly liquid magma. There are no broken frag- ments of one rock in another, there is never the slightest trace of a rapidly closed selvage, and there is no fluxion structure. The bounding surfaces of these rocks are always rounded, not angular, though where patches are of lentic- ular shape they may be drawn off to points at either end. No better simile could be found for the relations of these various rocks than the intermixing of the different colours in the plainer kinds of “‘marbled’’ paper used by book- binders. There are the same flowing curves, sharp points and streaks, and the same sharp edges to the varieties of rock as to the different colours. It is impossible in words to convey a correct idea of the relations of the kinds of rock in the segregation veins, and we have therefore reproduced here sketches and photo- graphs of such parts of the veins, easily accessible in the lower part of the Reservoir Quarry, as seemed to exhibit specially wellin asmall area structures which are common throughout the great veins and occur also in others. In Plate XXXVII is recorded part of the upper great segre- 532 4H. S. JEVONS, H. 1. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. gation vein near the middle of the Reservoir Quarry. It shows the relations of the medium and fine aplites, and the fine and coarse grained pegmatites, the aplites as usual lying in the middle of the vein in wavy streaks. Fig. 4 is a sketch of the large irregularly oval segregation mass in the upper great vein in the Reservoir Quarry, already referred to, which is located near letter H in Plate XXXV. It is an arched lenticular swelling of the vein, both the pegmatite and aplite becoming thicker. Two veins con- sisting of varieties of aplite branch off from the middle downwards. The following is a measured section across the thickest part of the vein at this point :— Pegmatite grading imperceptibly into normal essexite ... che ... | 1 2-mehies Pegmatite with veins of aplite ct) | 2G Aplite medium to coarse Las LL. OOZ6S Tees Pegmatite bss be 24! Pegmatite grading into normal essexite 24 ,, Total43: Je TORTS It has been possible to take a few photographs of the segregation veins, and two of them are reproduced in the plates to be found at the end of this paper. In Plate XXXVII we see a portion of the upper great aplitic vein taken near the middle of the Reservoir Quarry. On either side lie coarse and fine pegmatite and in the middle medium and fine aplite. A little study of the photograph shows that the arrangement of the different varieties of rock, though somewhat irregular, is not devoid or order. The medium aplite occurs only as a strip of varying width in the middle of the vein; it is bordered by fine aplite, and the pegmatite occupies the rest of the vein above and below. The coarse aplite here occurs mostly in the shape of bulging pockets. The dimensions of the vein measured 7 = GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 533 across the middle of the picture from top to bottom are these :— Coarse pegmatite oe ES) CMs.) 4296! Inches! Fine pegmatite ... EF ENZO) OR | Bee Wine and medium aplite... 75 ,, elas! Fine pegmatite ... ee Wied, 4 02 ,, Coarse pegmatite 1 NESS Ps ise Approximate total width 62 sn 24 ~«, A photograph of the lower great vein only a few metres from the part just described is reproduced in Plate XXXVIII. Measuring across the vein it is composed as follows :— Pegmatite a Smeles: Medium aplite .. 2 ,, Coarse aplite }; to; ,, Medium aplite ... 24 ,, Pegmatite ee tae Total... etal: ee The specimen shows the full width of the whole vein at this point. As usual the aplite occupies the middle of the vein. A vein containing aplite only will be seen branching downwards at the left of the photograph. This vein con- tains medium aplite and is about 14 to 2 inches in thickness. A specimen of fine-grained aplite, with a vein of coarse- grained aplite traversing it is, reproduced in Plate XL. The aplite is light greyish-green in colour, the individual crystals of felspar are just visible with the naked eye, and the fracture is rather rough. In general appearance it reminds one rather of a solvsbergite, but the green colour is not so bright, being chloritic. The vein of coarse-grained aplite has sharply defined and irregular boundaries. Opposite edges do not fit into one another, either on this side or on the reverse, hence the vein is probably not a small dyke or injection into a fissure. If it were so, the fissure must have been formed in some most unusual manner. The tabular crystals of albite can be clearly seen, and some black crystals of augite. Some dull patches are crystals of secondary dolomite showing curved faces and absence of lamellar twinning under the micro- scope. In this, as also in the fine-grained aplite, the tabular felspar crystals lie in all directions, there being no trace of fluxional parallelism. 534 H.S. JEVONS, H. 1. JENSEN, T. G. TAYLOR AND C. A. SUSSMILOH. There remains one feature worthy of close attention. The fine-grained aplite appears to be associated with the medium or coarse-grained aplite in two ways; it often occurs in blobs or rounded masses which look as if they had been suspended in the coarser aplite, but also occurs as a definite band or ‘‘selvage’’ on either side of the coarser aplites, i.e., between the coarse aplite and the pegmatite. The following section measured from the upper vein near the south end of the quarry illustrates this :— Thickness. Pegmatite ‘nate ... 6 inches Fine aplite Bey) Abo ee Medium to coarse aplite 10 _,, Fine aplite oe sonk il teers Pegmatite sar lee otal, “<..4o kee 19. Petrological description of the Pegmaiites and Aplites. The aplites and pegmatites differ little from point to point. except as regards grainsize. Itappears unnecessary there- fore, to describe a number of individual specimens, and we give a generalized description, first of the pegmatites and then of the aplites, in tabular form. 3 PEGMATITES. Megascopic Description.—Colour: At a distance, dark greenish-grey ; near at hand, speckled white, dark green GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 535 and black. Grainsize: Coarse, varies in different specimens from 2 mm. to10 mm., and occasionally more. Commonest grainsize 2°5 to 3mm. (denoted fine-grained, limits 2 to 5 mm) and 5 to 10 mm. (coarse-grained, limits 5 to 10 mm.). Minerals visible: Felspars, white or chloritic green. Long rectangular crystals are often seen beautifully zoned, the centre clear and glassy, and thus appearing rather dark, the outer zone opaque white owing to kaolinisation. The boundary between the zones is sharp, and is marked ina few crystals by a thin dark line of chlorite, which makes a perfect rectangle. Black prisms of augite are common, and needles of apatite may be seen with alens. There are also abundant white patches of analcite, and dark green masses of chlorite. Microscopic Description. Texture: Holocrystalline, hypidiomorphic-granular. Grainsize, see above. Minerals present :— Corrected. As measured ee aadonite Nf cee aw) 49°0 Albite:”’s.. sh soo GIES 31°4 Pyroxene (augite, diopside and egyrine-augite) 11 8°2 Ilmenite ... ee ee 51 Apatite ... Be ee Os: 0°5 Secondary—Analcite .. ae eh o 38 Chloritoid mad piltedtis Ane 2°0 100°0 100°0 The measurement was made by about 350 separate lengths on each of two slides. In the correction the anal- cite has been divided nearly equally between the albite and labradorite because there is much difficulty in deciding what it replaces when it occurs in patches, and a small allowance has been made for the tendency to overestimate the colored constituents. The measurement should only 536 4H. S.JEVONS, H. I. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. be taken as affording a very rough idea of the composition of the pegmatites. Felspars. The plagioclase is mostly idiomorphic and thick tabular in habit, all the larger crystals being zoned. Under the microscope the interior is usually seen to be fairly clear and glassy, and is proved by the R.I. being markedly higher than balsam, and by the extinction angles in symmetrical sections ranging up to 24°, to be an acid labradorite. These labradorite centres must be nearly uniform in composition throughout, for they show shadowy extinction only very slightly. Perhaps at their edge they may be acid enough to be called andesine. Then there is a sudden transition to practically pure albite which has a mean R.I. very slightly, though distinctly below that of balsam. These outer zones of albite are turbid and brownish in colour from kaolinisation, and twinning on the carlsbad and albite laws is continued in them from the labradorite centres. Peri- cline twinning occurs, though rarely. On measuring the diameters across some of the short lath-shaped sections, we found that the albite occupies about a quarter of the diameter, the figures on three well formed crystals being respectively 30, 25 and 27 per cent. Remembering that the alkaline felspar forms the outer shell of the crystal, calculation shows that at this ratio of diameter, each completely formed crystal must consist of 60 per cent. of alkali felspar, and 40 per cent. of the acid labradorite. This proportion appears somewhat startling in comparison with the results of the Rosiwal measurement, but the dis- crepancy is easily accounted for by the fact that the crystals never are perfectly developed, more than half the space of the albite zone being occupied by interfering crystals. The alteration of labradorite to analcite along cracks and cleavage planes, producing veins and small patches of eared GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 537 the mineral, is common in the pegmatites as in the main mass. A photograph of one of the large plagioclase crystals between crossed nicols is shown in Plate XXXIX, Fig. 5, which shows the analcite plainly. There is also seen the carlsbad twin-plane in the upper part of the picture, and in the lower part faintly the kaolinised outer zone of alkali felspar. The analcite veins are very clearly seen by ordinary light if the condenser be sufficiently stopped down. Pyroxenes. There are three varieties of pyroxene present in the pegmatites :— (1) A pale green non-pleochroic diopside in nearly idio- morphic stout prisms, some, but not all, having an outer zone of egyrine-augite. | (2) A light purplish-brown feebly pleochroic augite with hour-glass structure, chiefly in large prisms reaching occasionally 3 cm. in length, but partly also interstitial to felspar, and generally similar to the augite of the main rock. It is never bounded by egyrine-augite. (3) Aigyrine-augite, pleochroic from dark grass-green and olive-green to yellow, irregularly distributed as small imperfect prisms and as a narrow outer zone to the diopside crystals. One instance only was observed of intergrowth of the brown augite and the diopside, the latter occurring as an irregular outer zone. In relative abundance the brown augite is predominant, and the egyrine-augite quite sub- ordinate, forming less than one per cent. of the rock. Other Minerals. The other minerals are all similar to those occurring in the main rock. The biotite is of the usual strongly pleo- chroic brown variety, the crystals averaging about 1 mm. in diameter. The ilmenite presents a triangular skeleton 538 H.S8.JEVONS, H. 1. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. structure very perfectly in places, and is variable in quantity, ranging from 3 to 8 per cent. in different parts of the normal pegmatite, whilst basic patches occur here and there much richer in ilmenite. Apatite is abundant and its prisms frequently surpass 3 mm. in length. APLITES. Megascopic Description.—Colour: White, grey or pale green. Grainsize: (a) the fine-grained type 0°1 to 0°15 mm.; (b) the medium-grained type 0°25 to 0°75 mm.; (c) the coarse-grained type 1to2 mm. Minerals visible: felspar, sometimes pyroxene, rarely biotite. Miarolitic structure is not uncommon, particularly in the coarser types. Microscopic Description.—Texture: Holocrystalline, almost panidiomorphic-granular. Grainsize, see above. Minerals present :— Original—A lbite Orthoclase (? anorthoclase) Pyroxene (diopside, augite, and egyrine-augite) Biotite (rarely) Ilmenite Apatite Secondary—Analcite Chloritoid and chlorite Calcite The Felspars. These, which consist of albite and orthoclase (? anortho- clase), make up from 70% to 85% of the rock. They are always idiomorphic and thick-tabular in habit. Under the microscope they are seen to be much kaolinised, while some crystals show alteration into analcite. The chloritoid decomposition products are frequently present, sometimes marginally arranged. The albite crystals have a R.I. distinctly lower than that of the canada balsam, and in sections symmetrical to the albite lamellae, give extinction GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 539 angles up to 16°. Pericline twinning is occasionally seen. The orthoclase exhibits carlsbad twinning, but is too decom- posed for an accurate determination as to whether it is anorthoclase or not. Pyroxene. This mineral is present in relatively small quantity and usually occurs as small idiomorphic crystals, wholly or partly enclosed in the felspars. It is usually a pale green, non-pleochroic diopside, with in some of the larger crystals an inner zone of purplish-brown feebly-pleochroic augite. A thin outer zone of egyrine-augite is occasionally present. In one slide only, numerous small idiomorphic crystals of gegyrine-augite occurred, associated with much biotite. The pyroxenes are much less altered than the felspars, pro- ducing chloritoid decomposition products. Some crystals have been partly replaced by calcite. Other Minerals. These are all similar to those described as occurring in the pegmatite veins, but are, for the most part present in less quantity. The following is an analysis of the aplite by J. C. H. Mingaye with the norm calculated from it:— Analysis, coarse Aplite. Molecular ratio. Norm. % SiQ, 58°82 980 Quartz 1°92 Al,O, 16°91 166 Orthoclase 17°79 Fe,O, 2°40 015 Albite 06°59 FeO 4°59 064 Anorthite 6°95 MgO O38 022 Corundum 0°10 CaO 2°42 043 Hypersthene 6°82 Na,O 6°74 109 Magnetite ~ o'48 K,O 2°96 032 Ilmenite 2°13 H,O 100 C. A eoeh 141 Apatite 0°62 H7O 100 COC; + 1°98 Calcite 1°20 CO, 0°54. 012 HO, and Cl 2°55 TiO, 1°14 014 —_——— P.O; 0°34 002 Total 100°15 Cl O-01" — 5 —_——— MnO 0°13 001 Total 100°42 aed ‘ 540 4H. 8S. JEVONS, H.I. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. Class—Dosalane. Order—Germanare. Rang—Monzonase. Subrang—Akerose (Magmatic Name). In view of the decomposition which this rock has under- gone, as evidenced by the presence of calcite, chlorite, and other decomposition products, it is necessarily difficult to ‘form a satisfactory estimate of the ‘‘ mode,” and it is still more difficult to satisfactorily calculate the mode of the unaltered rock. The calculation is given in Appendix I with the following result :— Ilmenite ike cee a ae saa 2°2 Orthoclase ... af ee or ms 18°2 Albite.... ss«. sei; seed 1) Ste rr Anorthite ... Rs a, ae at 4°0 Magnetite ... ae #3 Bs see 2°8 Pyroxene ae ae vos se it: 15°8 Apatite ae ae sah oe As. OF 100°0 The amount of pyroxene shown is somewhat larger than the examination of a number of slides led one to expect. Appendix I. Determination of the Mode. ) The calculation of the mode, or actual mineral compo- sition, of a rock is possible, as pointed out by Cross, Iddings, Pirsson and Washington,’ only when it contains not more than one ferric or alferric mineral, unless the compositions of any such minerals present be known. If there be more than one alferric mineral present, it is necessary to know, not only the composition of each, but also the quantity present of all but one. Hence the calcu- lation of the mode entails, if it is to be done accurately, ? Quantitative Classification, p. 210. GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 54] not only the separation and analyses of all the ferric and alferric minerals present, but also the measurement of the rock by the Rosiwal method. Whenall the necessary data are not available it is possible to calculate the mineral composition approximately by making reasonable assump- tions as to the composition of one or two minerals, or their quantity. Thisis the course we have followed with regard to the Prospect rocks. The composition of the augite we know by analysis. We assumed a composition for the biotite agreeing closely with a number of analyses of biotite from igneous rocks and left the composition of the olivine to be determined by the remainder. A check was obtained, however, by the necessity of assuming the olivine to have the same composition in both specimens. This led toaslight re-adjustment of the proportion of FeO and MgO molecules in the biotite; and aclosely approximate solution of the compositions of the rocks was finally obtained with the assumption of the following compositions for biotite and olivine:— BIOTITE. OLIVINE. Molecular. By Weight. Molecular. By weight. SiO, 40 BY ip 30'4 oo 2 AsO 11 17°3 Fe,0, 4 9°9 FeO 10 alsa o2° t 40°1 MgO 20 12°4 o4°2 24°0 K.O 6 Sidiw. « H,O 8 2°2 TiO» 1 1°2 100 100°0 100°0 100°0 It will be seen that, whilst the biotite has quite a normal composition, the olivine is unusually rich in iron, and isa hyalosiderite, approaching fayalite. Its composition as here found is not dependent on the composition assumed I 1—Dee. 6, 1911. 542 4H. 8. JEVONS, H, I. JENSEN, T. G. TAYLOR AND C. A. SUSSMILCH. for the biotite, but is conditioned by the remainders of FeO and MgO after allotting for the augite and magnetite in specimen I, which contains an insignificant quantity of biotite as will be seen on referring to the table of mole- cular proportions for that specimen. Confirmation of the high iron content of the olivine is to be found in the deep colour of the serpentine, whether brown or green, resulting from its alteration. Further verification of its ferriferous nature seemed desirable, however, and the only readily available means appeared to be the determination of the strength of double refraction, for according to the figures of Levy and Lacroix* that of olivine is ‘036, that of natural fayalite °049 and of artificial fayalite ‘043. Sections of specimens B and Y in which the olivine is abundant and little altered were searched, and the section giving the highest colour examined in convergent light, with the result that a section was found in Y very nearly parallel to the optic axes, in Bone not so nearly parallel, but sufficiently so to be worth examining further. The highest colour shown by any of the labradorite crystals in the vicinity of the olivine crystal chosen was then found. In both cases it lay in the first order yellow to red, and was accurately determined by addition and subtraction with a quarter- wave plate. The olivine crystals were found to be heterogeneous in composition. Most of the crystals have an outer zone distinctly stronger in double refraction than the interior of the crystal section, the strength of D.R. increasing gradu- ally but rapidly on nearing the edge of the section. Inone or two cases, however, the zone of stronger D.R. was wrapped round an irregular centre of weaker D.R., the boundary between the two being perfectly sharp. The readings, and the results obtained by us of Michael Levy’s chart are shown in the following table. ‘* See Mineraux des Roches, pp. 248-9. GEOLOGY AND PETROGRAPHY OF THE PROSPECT INTRUSION. 543 g Colour of Olivine between i Thickness of .. Minimum — erossed nicols. Maximum phase) slice in neigh- | Possible D.R. ® =~ difference (eX) | pourhood of a Interior. Outer Zone. of labradorite. | olivine crystal. | Inte:ior. Optex a Tee fe PBOUCS Y|GreenIV! Red IV =) 450 pp "050 mm. | ‘038 |°042 Ord. Ord. | B| Red IV | Green V_ 505 ,, "098 ,, | °037 |°041 Ord. Ord. | | The chief element of uncertainty was found to be the D.R. of labradorite, which is here taken as ‘009. Levy and Lacroix give ‘008 for both albite and labradorite, and °013 for anorthite, but their determination for labradorite is admittedly accurate only to within °002. If ‘008 is correct for albite, and this seems to be in accordance with general experience,’ the probability would seem to be that the D.R. of labradorite is ‘009 at least, assuming that the progressive change in properties with composition holds good for D.R.as with all the other optical properties. The results in the two slides agree very closely when allowance is made for the section in B not being quite parallel to the optic axes. If the D.R. of labradorite be assumed to be °0085 the D.R. of the olivine must be reduced in each case by °002. The figures obtained certainly agree with the hypothesis that the olivine is more than usually ferriferous. There can be no question as regards the difference of D.R. by °004 between the interior of crystals and the outer zone, so that, even if the interior of the crystals be olivine of normal composition, nearly one-third of the volume of the phenocrysts, and the whole of the not very numerous small crystals of the groundmass, must be unusually rich in iron. In the two specimens in which the composition of the augite was known, it was found that the silica was deficient for producing albite with all the soda. At first thought the presence of nepheline would be inferred from this, but there is no microscopic evidence whatever of the original 1 Of. the determination of the D.R. of the andesine of Baskerville as °0081 by Offret (Bull. Soc. Min., France, 1890, x111, p. 648.) 544 4H.S. JEVONS, H. I. JENSEN, T. G. TAYLOR AND O. A. SUSSMILCH. presence of any lenad—not the slightest suggestion of it. A deficiency of silica is not uncommonly found in calculating modes from chemical analysis, and it is most probable that in this, as in other cases, the deficiency is due to the de- composed state of the rock. A slight under-estimation of ferric iron would have the same effect by producing an underassignment of magnetite; and it is just possible, considering the difficulties of ferrous iron determinations, that a small part of the deficiency may be due to this cause in specinen B, in which the ferric iron is particularly low and the deficiency of silica rather high. The removal of silica during decomposition is undoubtedly the main cause of the deficiency of silica, as shown by the presence of much secondary analcite; and in calculating the modes, silica has therefore been added sufficient to form polysilicates of the whole alkalies excluded from the alferric minerals. MopDE OF SPECIMEN I. The quantity of biotite present was assumed to be a. little less than 2 per cent., in conformity with the micro- scopic evidence, and the number of molecules of oxides in the proper proportion necessary to make this quantity was. calculated. Allotment then proceeded as in the following table, equations involving lime-alumina ratios being used to determine the augite and anorthite :— ae Ps E eae g rt oor “A =| — 3 o ° a = Oo ee gP8/ 3/3 /8/2/2/8 1/2) 8] 2] 2 | & g q ra) 2 g i) TE es =} gq 3 = = = ce Ss eb fe ee PS qi < » ms In Advance... GG. To Parliamentary Grant on Subscriptions received— Vote for 1910-1911 » Rent >, Sundries.. », Exchange waded a Conane cheduees », Clarke Memorial Fund—Loan ‘To Balance on Ist April, 1910 ... PAYMENTS. By Advertisements », Assistant Secretary .. » Books and Periodicals », Bookbinding ... », Caretaker », Hlectric Light .. » Freight, Gheeses, Packing. ate » Gas A laaeice ; » Interest on Mortgage, » Office Boy : », Petty Cash Be penses:.. » Postage Stamps » Printing » Printing and PubHeRing J eienal’ Carried forward £85 15 2 272 8 29 3 2 33 5 2 249 9 11 975 ll 3 vil. ABSTRACT OF PROCEEDINGS. PAaYMENTS—contiuued. £ siggy £748. 2 Brought forward _... R 975 11 3 By Rates... ane 510 sot ae a 6412 9 », Repairs... $i ode Bot ve es 4210 2 » Stationery ay, an bh 3 a aes 13. 7,46 >», sundries Ae ie ee hives Ai 37. Lae » Conversazione.. cf 638 2 3 », Clarke Meroe Wind“ Resaide ineake General Account cae ie aa eal3O) Tow 5 Ditto, ditto, Interest... ee a Bae ds aaa : -_—— 131 19 10 » Bank Charges ... : ae Bae 016 8 », Cash in hand 31st March, 1911 ce Ae 2. toa ,», Cash in Bank on 3lst March, 1911... Py 108 2 8 £1461 16 10 BUILDING AND INVESTMENT FUND. Dr. BS as To Loan on Mortgage at 4% _ ... wee Oe: wt «~« olLOOP ima Clarke Memorial Fund—Loan nas a vig ae 18 15 11 33 £3118 15 11 Cr. £ sod. By Deposit in Government Savings Bank, March 81st, 1911 1. Se2 Balance of Account, 3lst March, 1912 ... SA0 |) Saas 3) £3118 15 11 CLARKE MEMORIAL FUND. Dr. £ Sa! To Amount of Fund, 31st March, 1910 ... me cide =.) (SOLA », Interest to 3lst March, 1911 ... an 8 1a . it) LOR Ss », General Account Repaid on a/c Loan he of M3OREG 1 » General Account, Balance _... ae a 700 un 2a! 16 | £649 2 3 Cr. £ "3d By Deposit in Savings Bank of N.S. W., March 31,1911 ... 285 1 9 », Deposit in Government Savings Bank, March 31,1911 ... 214 8 6 ,, Repaid on a/c Loan to Building and Investment Fund ... 18016 1 » Loan to Building and Investment Fund ... une vi LS eae £619 2 3 AUDITED AND FOUND CORRECT, AS CONTAINED IN THE BOOKS AND ACCOUNTS. W. PERCIVAL MINELL, F.c.v.a., Auditor. D. CARMENT, r.1.a., F.¥.a., Honorary Treasurer. SrYDNEy, 26TH APRIL, 1911. ABSTRACT OF PROCEEDINGS. Vil. On the motion of Mr. HENRY DEANE, seconded by Mr. HovueutTon, Mr. W. P. MINELL was duly elected auditor for the ensuing year. On the motion of Mr. J. H. MAIDEN, seconded by Mr. R. H. CamBace, Mr. W. Borrinc HEMSLEY, F.R:S., late of Kew, was unanimously elected an Honorary Member in recognition of his distinguished services in promoting a knowledge of the Australian Flora. Ninety-six volumes, 169 parts, 15 reports, 7 pamphlets, and 15 maps were laid upon the table. There being no other nominations, the following gentle- men were declared duly elected Officers and Members of Council of the Royal Society of New South Wales for the ensuing year :— President: J. H. MAIDEN, F.u.s. Vice-Presidents; W. M. HAMLET, rF.t.c., F.c.s. F. H. QUAIFE, m.a., 1p. H. D. WALSH, B.A.I., M. Inst.C.E. | Prof.T.W.E. DAVID, c.m.a., B.a.,D. Se, Hon. Treasurer: D. CARMENT, t.1.4., F.F.A. Hon. Secretaries: F. B. GUTHRIH, F.1.c., F.c.s. | Prof. POLLOCK, D.Sc. Members of Council: mh oH. CAMBAGE;, .S:, F.1.S. CHARLES HEDLEY, F.u.s. H. G. CHAPMAN, m.p. T. H. HOUGHTON, M. Inst. 0.8. J. B. CLELAND, ™.pD., ch.m. : HENRY G. SMITH, F.c.s. HENRY DEANE. ™.a., M. Inst. c.B.| Prof. WARREN, M. Inst.C.E., Wh.Se. R. GREIG-SMITH, D.Sc. W.G. WOOLNOUGH, D.Se., F.G.8. The President made the following announcement :—that the Geological Section, of which Mr. J. EH. CARNE, F.G.S., was Chairman, and Mr. C. A. SUSSMILCH, F.G.S., Honorary Secretary, would meet every second Wednesday in the month, unless members were otherwise notified. Professor T. W. EK. DAvip then delivered his Presidential Address. Vill. ABSTRACT OF PROCEEDINGS. In it he referred to the loss which the Society has sus- tained during the year in the deaths of Dr. WALTER SPENCER and Mr. W. J. MACDONNELL. Dr. SPENCER had not only given to the Society the benefit of his services as a member of the Council, but had of late been prominent as president of the New South Wales branch of the British Science Guild. His efforts to secure larger playgrounds and reserves for the school children had been crowned with success, and his good work would live after him. Mr. MACDONNELL was esteemed as a patient and enthusiastic worker in Astronomy. Reference was made to the recent Antarctic expeditions under Captain Scorr and Captain AMUNDSEN and Lieutenant SHIRASE, and a strong appeal was made to the members of the Royal Society to support Dr. DoUGLAS MAWSON in the Australasian expedition which he was now organizing with so much energy. An outline was given of the preliminary scientific work about to be undertaken in the Northern Territory, on behalf of the Federal Government, by Professors BALDWIN SPENCER and GILRUTH of Melbourne University, Dr. BREINL of the School of Tropical Medicine, and Dr. W. G. WooLNouGH as Geologist. This expedition, which starts early in June and which will be away for about eight or ten weeks, is intended to be a prelude to a larger expedition in which every branch of Science bearing on the problems of the Northern Terri- tory will be represented. The special subject of the address was the geological structure of the Australian Continent, especially in relation of the evolution of its mountains, valleys, plains and plateaus. A large scale relief map of Australia and Tas- mania, specially prepared for illustrating these features by Mr. W. K. MoIntTyRE of Sydney University, was exhibited. This was based on an accurate map kindly supplied by Mr. H. E. C. Ropinson. ABSTRACT OF PROCEEDINGS. ix. At the conclusion of the address, a very hearty vote of thanks was given to the retiring President, and Mr. J. H. MAIDEN was installed as President for the ensuing year. ABSTRACT OF PROCEEDINGS, JUNE 7, 1911. The three hundred and forty-first (341st) General Monthly Meeting of the Royal Society of New South Wales was held at the Society’s House, 5 Hlizabeth-street north, on Wednesday, June 7th, 1911, at 8 p.m. Mr. J. H. MAIDEN, President, in the Chair. Twenty-eight members were present and ten visitors. The minutes of the preceding meeting were read and confirmed. The certificates of candidates for admission as ordinary members were read; one for the second, and one for the first time. Mr. W. J. CLUNIES Ross and Mr. WILLIAM WELCH were appointed Scrutineers, and His Honor Judge DOCKER deputed to preside at the Ballot Box. The following gentleman was duly elected an ordinary member of the Society :— R. D. WATT, M.4., B.Sc, Professor of Agriculture in the University of Sydney. The President made the following announcements :— (1) That the Council had decided to open a subscription list in favour of Mr. W. H. WEBB, who had resigned the office of Assistant Secretary, after a service of thirty-four years. (2) That aseries of Popular Science Lectures, illustrated by lantern slides, experiments, or diagrams, would be held during the Session, on the following dates, at 8 p.m. :— June 15—‘“ Insects and Disease,” by W. W. FROGGATT, F.L.S8. x; ABSTRACT OF PROCEEDINGS, July 20—“ The Ancient Italian House, with special reference to Pompeii,” by Dr. F. A. Topp. August 17—“ The Reign of Ill-custom in English Spelling,” by Professor HE. R. Hoime. September 21—“ The History of Taxation,” by B. R. GuLiine. (3) That a meeting to further the objects of Dr. MAWSON’s Antarctic Expedition would take place in the vestibule of the Town Hall, Sydney, on June 13th, at 4 p.m. (4) That the Geological Section would not meet this month. (5) That donations consisting of 22 volumes, 88 parts, 12 reports, 24 pamphlets, and 3 maps, were laid upon the table. THE FOLLOWING PAPERS WERE READ: 1. ‘‘ Notes on Transition Curves,’ by W. SHELLSHEAR, M. Inst. c.B. In the absence of the author, the paper was read by Mr. H. DEANE. 2. ““Notes on the Oxy-acetylene Welding Process,’ by Prof.S. HENRY BARRACLOUGH, with a practical demon- stration of cutting and welding steel by Mr. GEORGE IKENNEDY. ABSTRACT OF PROCEEDINGS, JULY 5, 1911. The three hundred and forty-second (342nd) General Monthly Meeting of the Royal Society of New South Wales was held at the Society’s House, 5 Elizabeth-street north, on Wednesday, July 5th, 1911, at 8 p.m. Mr. J. H. MAIDEN, President, in the Chair. Twenty-one members and one visitor were present. The minutes of the preceding meeting were read and confirmed. ABSTRACT OF PROCEEDINGS. xi. The certificates of candidates for admission as ordinary members were read; one for the second, and one for the first time. Dr. H. STok#&s and Dr. COOKSEY were appointed Scru- tineers, and Mr. D. CARMENT deputed to preside at the Ballot Box. The following gentleman was duly elected an ordinary member of the Society :— CHARLES FRANCIS LASERON, The Technological Museum, Sydney. | The President made the following announcements :— (1) That the Popular Science Lecture on ‘‘The Ancient Italian House, with special reference to Pompeii,’’ by Dr. F’. A. ToDD, would be delivered in the Society’s House on July 20th, 1911. (2) That a printed announcement referring to a proposed testimonial to Mr. W. H. WEBB has been distributed in the hall for members. (8) That donations consisting of 13 volumes, 90 parts, 9 reports, 3 pamphlets, and 5 maps were laid upon the table. THE FOLLOWING PAPERS WERE READ: 1. “Observations on the Corrosion of Steel in Water,” by G. J. BURROWS, and OC. H. FAWSITT, D. sc., Ph. D. Prof. Davip, Mr. DARNELL-SMITH, Dr. CooOKSEY and Dr. STOKES took part in the discussion. 2. ““On the application of Fourier’s Series to Statistical Data, illustrated by the Analysis of Fluctuations of Annual Period in Rate of Marriage, Temperature, Suicide etc.’’ by G. H. KNIBBS, C.M.G., F.R.A.S., F.S.S., etc., Commonwealth Statistician. Read in abstract by Mr. F. B. GUTHRIE. X11. | ABSTRACT OF PROCEEDINGS, 3. “Hehinorhynchus pomatostomi, a subcutaneous parasite of Australian Birds,’’ by T. HARVEY JOHNSTON, M.A., D.Se. and J. BURTON CLELAND, M.D., ch.m. Read by Dr. J. B. CLELAND. EXHIBITS. (1) Two volumes Eleventh Hdition of Hncyclopedia Britannica on India Paper, by F. H. QUAIFE, M.A., M.D. (2) The Digby and Biggs Dionic Water Tester, by Dr. HK. STOKES. ABSTRACT OF PROCEEDINGS, AUGUST 2, 1911. The three hundred and forty-third (343rd) General Monthly Meeting of the Royal Society of New South Wales was held at the Society’s House, 5 Hlizabeth-street north, on Wednesday, August 2nd, 1911, at 8 p.m. Mr. J. H. MAIDEN, President, in the Chair. Twenty-four members and one visitor were present. The minutes of the preceding meeting were read and confirmed. One new member, Professor R. D. WATT, ™.a,, B.se., enrolled his name and was introduced. The certificate of a candidate for admission as an ordinary member was read for the second time. Mr. LAWRENCE HARGRAVE and Mr. CLUNIES Ross were appointed Scrutineers, and Dr. QuAIFE deputed to preside at the Ballot Box. The following gentleman was duly elected an ordinary member of the Society :— EDWARD STEVENSON SMITHURST, 7 Bridge-st., Sydney. The President made the following announcements :— (1) That the Popular Science Lecture on *‘ The reign of ill-custom in Hnglish Spelling,’’ would be delivered by ABSTRACT OF PROCEEDINGS. Xlli. Professor EH. R. HOLME, M.A., in the Society’s Hall, on the 17th August, 1911. (2) That Volume xiv, of the Society’s Journal would be ready for distribution to members in about two weeks. (3) That donations consisting of 34 volumes, 155 parts, 8 reports, 3 pamphlets, and 5 maps had been laid upon the table. CORRESPONDENCE. Letter from Mr. W. Borrinc HEMSLEY, F.R.S., expressing his thanks to the Society on his election as an Honorary Member of the Society. THE FOLLOWING PAPERS WERE READ: 1. ‘* Hrosion and its Significance,’’ by E. C. ANDREWS, B.A., read in abstract by Mr. C. A. SUSSMILCH, in the absence of the author. 2. ** Notes on the Geology of West Moreton, Queensland, by W. G. WooLNOUGH, D.Sc, and R. A. WEARNE, B.A., read in abstract by Mr. C. A. SUSSMILCH in the absence of the authors. 3. ‘‘ Preliminary Note on the Nepheline-bearing Rocks of Liverpool and Mount Royal Ranges,”’ by W. N. BENSON, __ B.Se. 4, ‘““Geology of the Kempsey District,’’ by W. G. WooL- NOUGH, D.Sc, read in abstract by Mr. C. A. SUSSMILCH, in the absence of the author. 5. “The effect of Heating and Antiseptic Treatment on the Solubility of the Fertilising Ingredients in Soils,” by H. I. JENSEN, D.sc., read by Mr. F. B. GUTHRIE, in the absence of the author. 6. ““The Origin of the Small Bubbles of Froth,’’ by Prof. J. A. POLLOCK, D.Sc. Xiv. ABSTRACT OF PROCEEDINGS. ABSTRACT OF PROCEEDINGS, SEPTEMBER 6, 1911. The three hundred and forty-fourth (344th) General Monthly Meeting of the Royal Society of New South Wales was held at the Society’s House, 5 Hlizabeth Street north, on Wednesday, September 6th, 1911, at 8 p.m. Mr. J. H. MAIDEN, President, in the Chair. Twenty-seven members were present. The minutes of the preceding meeting were read and confirmed. One new member, Mr. HDWARD S. SMITHURST enrolled his name and was introduced. The certificate of one candidate for admission as an ordinary member was read for the first time. The President made the following announcements :— (1) That a Popular Science Lecture, entitled ‘‘A Brief History of Taxation,’’ by Mr. B. R. GELLING, F.S.S., would be delivered in the Society’s Hall, on Thursday evening, September 21st, 1911, at 8 p.m. (2) That the Geological Section would not meet this month, many of the geologists being away in the country. (3) That donations consisting of 26 volumes, 135 parts, 9 reports, 10 pamphlets, and 5 maps had been laid on the table. CORRESPONDENCE. A letter from His Excellency the Governor General con- senting to act as Patron of the Society was read. The President announced to the meeting the death of Mr. F. W. WHITE, printer to the Society for over half a century, and the meeting resolved to express its sincere condolence to the relatives of Mr. WHITE. THE FOLLOWING PAPERS WERE READ: 1. ‘‘Suicide in Australia, a Statistical Analysis of the facts,’’ by G. H. KNIBBS, C.M.G., F.R.A.S., F.S.S. etc., ABSTRACT OF PROCEEDINGS. XV. Commonwealth Statistician. Read in abstract by Mr. Ff. B. GUTHRIE. 2. “‘Notes on the Occurrences of Explosive Reports in the Interior of Australia, with suggestions as to their nature,’’ by J. B. CLELAND, M.D., ch.m. EXHIBITS. Mr. W. M. HAMLET exhibited a new wave length Spectroscope, by Hilger. Mr. WSDAILE exhibited a Stereo-telemeter by Zeiss. ABSTRACT OF PROCEEDINGS, OCTOBER 4, 1911. The three hundred and forty-fifth (345th) General Monthly Meeting of the Royal Society of New South Wales was held at the Society’s House, 5 Hlizabeth-street north, on Wednesday, October 4th, 1911, at 8 p.m. Mr. J. H. MAIDEN, President, in the Chair. Twenty-nine members were present. The minutes of the preceding meeting were read and confirmed. The certificate of candidates for admission as ordinary members were read; one for the second, and one for the first time. Mr. W. S. Dun and Mr. C. A. SUSSMILCH were appointed Scrutineers, and Mr. R. H. CAMBAGE deputed to preside at the Ballot Box. The following gentleman was duly elected an ordinary member of the Society :— JOHN HENRY MACARTNEY ABBOTT, Author, St. James’ Chambers. : Hleven volumes, 108 parts, 7 reports, 118 pamphlets, and 43 maps were laid upon the table. Xvi. ABSTRACT OF PROCEEDINGS. THE FOLLOWING PAPERS WERE READ: 1. ‘‘ Note on a new type of aperture in Conularia,” by OHARLES FH’. LASERON. 2. °*The River Gravels between Penrith and Richmond,”’ by H. I. JENSEN, D.Sc. A discussion then took place on ‘‘ Notes on the Occur- rences of Explosive Reports in the Interior of Australia, with suggestions as to their Nature,’’ by Dr. J. B. CLELAND, in which Dr. WooLNoUGH, Messrs. HARGRAVE, CAMBAGE, Dun, Dr. JENSEN, Messrs. SUSSMILCH, BARLING, CLUNIES Ross, and MATHEWS took part, and the author replied. EXHIBITS. (1) A new Miniature Model Brunsviga Calculating Machine; (2) Improved Type Large Model Brunsviga Calculating Machine; (3) Prismatic Compass, with Radium Illumination for use in mining or at night; (4) The Ver- schoyle Pocket Transit, by Mr. EK. EspDaILr. (5) Belemnites and Fossil Cephalopods from Port Darwin, by Dr. WOOLNOUGH. ABSTRACT OF PROCEEDINGS, NOVEMBER 1, 1911. The three hundred and forty-sixth (346th) General Monthly Meeting of the Royal Society of New South Wales was held at the Society’s House, 5 Hlizabeth-street north, on Wednesday, November ist, 1911. Mr. J. H. MAIpgEn, President, in the Chair. Thirty-one members were present. | The minutes of the preceding meeting were read and confirmed. The certificate of one candidate for admission as an ordinary member was read for the second time. ABSTRACT OF PROCEEDINGS. Xvil. _ Messrs. D. J. COLLEY and H. O. ANDREWS were appointed Scrutineers, and Dr. W. G. WooLNouGH deputed to preside at the Ballot Box. The following gentleman was duly elected an ordinary member of the Society. G. F. LONGMUIR, B.A., Science Master, Technical College, Bathurst. The President announced that the Geological Section would meet on Wednesday the 8th November, at 8 p.m. Fifteen Volumes, 121 parts, 14 pamphlets, 4 maps and 4 reports were laid upon the table. A letter from Mr. G. H. BLAKEMORE re frost markings was read. With reference to the death of Mr. WILLIAM SUTHERLAND, M.A.,D.Sc., Of Melbourne, it was proposed by Professor POLLOCK and seconded by Professor DAVID, that a letter of sympathy be forwarded to Miss SUTHERLAND; and with reference to that of Mr. NORMAN SELFE, an old member of the Society, it was moved by Mr. HouGHTON seconded by Prof. DAVID, that a letter of condolence be sent to his family. THE FOLLOWING PAPERS WERE READ: 1. ‘“‘An Autographic Air Flow Recorder,’’ by W. R. HEBBLE- WHITE, B.E., communicated by Prof. S. H. BARRa- CLOUGH, B.E., M.M.E., etc. 2. *‘Some New England Hucalypts and their Economics,”’ by R. T. BAKER, F.L.S., and H. G. SMITH, F.C.S. 3. ‘“On Rock Specimens from Central and Western Aus- tralia,’’ (collected by the Hider Scientific Exploring Expedition of 1891-2), by J. ALLAN THOMSON, B.A., B.Sc., F.G.S., communicated by Prof. T. W. EH. DAVID, B.aA., ©.M.G., F.R.S., Hon. D.Sc., Oxon, b—Dec. 6, 1911, XVill. ABSTRACT OF PROCEEDINGS. EXHIBIT. Rock from Volcanic Neck, Dundas, by Mr. Corron. ABSTRACT OF PROCEEDINGS, DECEMBER’6, 1911. The three hundred and forty-seventh (347th) General Monthly Meeting of the Royal Society of New South Wales was held at the Society’s House, 5 Hlizabeth-street north, on Wednesday, December 6th, 1911. Mr. J. H. Marpen, President, in the Chair. Thirty-three members were present and six visitors, including Mr. Davin LINDSAY, the South Australian Explorer. The minutes of the preceding meeting were read and confirmed. The certificate of one candidate for admission as an ordinary member was read for the first time. Five volumes, 141 parts, 12 reports, 2 pamphlets, and 1 map were laid on the table. The following letter was received from Miss SUTHERLAND: 4 Highfield Grove, Kew, Melbourne, November 23rd, 1911. To the Hon. Secretary of the Royal Society of N.S. Wales. Dear Sir,—Your letter of the 2nd instant received. Will you kindly convey to the members of the Royal Society of New South Wales, on behalf of the members of the family of the late Mr. W1LL1am SUTHERLAND an expression of appreciation and thanks for their kind letter of sympathy, and tribute to his work. Yours faithfully, JESSIE SUTHERLAND. THE FOLLOWING PAPERS WERE READ: 1. ‘A suggested explanation of Allotropism based on the Theory of Directive Valency, by F. B. GUTHRIE, F.1.C., F.C.S. 2. “The Nature and Origin of Gilgai Country,”’ by H. I. JENSEN, D.Sc. “I ABSTRACT OF PROCEEDINGS. xix, . “Some Curious Stones used by the Australian Abori- gines,”’ by R. H. MATHEWS, L.S. . “The Geology and Petrography of the Prospect Intru- sion,’’ by H.S. JEVONS, M.A., B.Sc., F.G.S., H. I. JENSEN, v.sc., T. G. TAYLOR, B.A., B.Sc., and OC. A. SUSSMILCH, F.G.S. . “The value of the Nitrate Figure in determining the fitness of water for drinking purposes,’’ by O.S. WILLIS, M.D., M.R.C.S. . “Notes on the occurrence of Tceniopteris in the roof of the Coal-seam at the Sydney Harbour Colliery,’ by W.S. DUN. . “The Geology of the Hruptive and Associated Rocks of Pokolbin, N.S.W.”’ by W. R. BROWNE, B.Sc., and A. B. WALKOM, B.Sc. . “The Haematozoa of Australian Birds,” No. 2, by J. B. CLELAND, ™.D.,Cch.m., and T. H. JOHNSTON, M.4A., D.Sc. . “On the Australian Melaleucas and their Essential Oils,” by R. T. BAKER F.L.S. and H. G. SMITH, F.C.S. * li. "> A> eA & “A i nd - why oy) TO oe ee Pea { 1 hee on \ ay it ; TA a3 ee { ay) ' rr a ¥ at a ait Dae GEOLOGICAL SECTION. re | mh } ABSTRACT OF PROCEEDINGS. XXilj. ABSTRACT OF PROCEEDINGS OF THE GEOLOGICAL SECTION. << - Monthly Meeting, Sth March, 1911. Mr. J. E. CARNE in the Chair. Ten members and two visitors were present. Mr. W. S. Dun exhibited a specimen of Glossopteris with some unusual characters from near Mudgee. Mr. C. A. SUSSMILCH exhibited crystals of Rhodonite from Broken Hill. Mr. W. N. BENSuUN exhibited some photographs from Terrigal, and made remarks on some of the physiographical features of the district surrounding Brisbane Water, which led to an animated discussion on the evidences of a recent small uplift. . On the motion of Mr. R. H. OAMBAGE, seconded by Mr. W.S. Don, the retiring President, Mr. J. H. CARNE, and the retiring Hon. Secretary, Mr. C. A. SUSSMILCH, were re- elected. . Monthly Meeting, 12th April, 1911. Mr. J. H. CARNE in the Ohair. Thirteen members and three visitors were present. Mr. W. S. Don, exhibited the wing of an hemipterous insect embedded in selenite from a copper mine at Mount Hiliott, Queensland, A discussion took place on (a) The Geographical Unity of Hastern Australia, by H. O. ANDREWS, and (b) A Study XXIV. ABSTRACT OF: PROCEEDINGS. of Marginal Drainage, (Presidential Address to the Linnean Society of N.S. Wales) by O. HEDLEY. The discussion was avery animated one, and was adjourned to the following meeting. Monthly Meeting, 10th May, 1911. Mr. J. H. OaRne in the Chair. Thirteen members and four visitors were present. Mr. W. S. DUN exhibited a specimen of the fossil coral Diphyphyllum from the Molong District, and made some remarks regarding the occurrence of Lower Devonian strata in that. region. The discussion started at the April meeting was con- tinued and concluded. The general principle of the geo- graphical unity of Eastern Australia in late Tertiary time was agreed upon, but there was some difference of opinion as to the nature and cause of the earth movement which closed the Tertiary Period. Monthly Meeting, 12th July, 1911. Prof. T. W. E. Davin in the Chair. Ten members and five visitors were present. Mr. W. N. BENSON gave a detailed account of the geology of the Nundle, Manilla, and Bingera districts, and Mr. DUN exhibited fossils of Devonian Age (Spongophyllum, Favo- sites, and Stomatopora), and Carboniferous (Lithostrotion) in connection therewith. Monthly Meeting, 9th August, 1911. Mr. R. H. CAMBAGE in the Ohair, Nine members were present. An informal discussion was held on a paper by T. GRIFFITH TAYLOR, B.Sc, on “The Physiography of Hastern Australia,” ABSTRACT OF PROCEEDINGS, XXV, Monthly Meeting, 11th October, 1911. Mr. J. HE. OARNE in the Ohair. Ten members were present. Mr. A.B. WALKOM exhibited an undescribed Oystiphylloid coral from Derrangullen Creek and a new species of Favo- sites from the same locality. Dr. W. G. WOOLNOUGH exhibited specimens of belemnites, ammonites and other cephalopods from Port Charles, Northern Territory, and a fossil crustacean from the same locality. A discussion then took place on the age of the alkaline igneous rocks of New South Wales. No definite conclusion was arrived at regarding the alkaline intrusives, except that they were Post-Triassic, but the general opinion regarding the alkaline volcanic rocks was that they were at least as young as Miocene. Monthly Meeting, 8th November, 1911. Mr. J. HE. CARNE in the Chair. Hleven members and three visitors were present. The principal business of the evening was a discussion on Professor T. W. E. Davin’s presidential address on “ The Ohief Tectonic Lines of Australia. ; On the motion of Mr. W. S. Dun a vote of thanks was passed to the Secretary for his efforts on behalf of the Section during the year. At the close of the meeting the Chairman, on behalf of the members wished bon voyage to Messrs. WATSON and HUNTER, two members of the Mawson Antarctic Expedition. XXVl. INDEX. A’ ees | Abstract of Proceedings as Air-flow recorder, Autographic 258 Allotropism, A suggested ex- planation of, based on the theory of directive valency 318 Andrews, EK. C., Erosion and its significance / LG Australian Melaleucas and their essential oils ... 865 B Baker, R. T., On some New England Eucalypts and their economics ... — Onthe Australian Mela- leucas and their essential — oils; part iv , 365 Benson, W. N., Preliminary note on the nepheline-bear- ing rocks of the Liverpool and Mount Royal ranges 176 Building and Investment fund vi. Burrows, G. J., Observations on the corrosion of steel in water ae ee (OF 267 Cc Clarke Medal, awards of (xxiv) memorial fund _... vi. Cleland, Dr. J B., Echinorhyn- chus pomatostomi, (n.sp.), a subcutaneous parasite of Australian birds ... Bee) Gi — On the occurrence of Ex- plosive or Booming noises (Barisal Guns) in Central Australia . 187 — The Haematozoa. of Aus- tralian birds, No.2 ~~... 415 Conularia, Note on a new type of aperture in . 247 Corrosion of steel in water, Observations on the hdd Council, members of... Jets ANAL report of ... wi Peony at D David, Professor T. W. E., Presidential Address ee Sas | Pags Dun, W. 8., Note on the occur- rence ea Teniopteris in the coal seam of the Sydney Harbour Colliery ... vee O04 E Kchinorhynchus pomastomi(n.sp.), a subcutaneous parasite of Australian birds ... af Erosion and its significance ... 116 Essential oils of Australian Melaleucas .. Eucalypts, On some New Eng- land, and their economics 267 Explosive or Booming Noises (Barisal Guns) in Central Australia, on the occur- rence of . 187 365 Fawsitt, C. E., Observations on the corrosion of steel in water 3 oes ant eB Financial statement... v Fitness of water for drinking purposes, value of the nitrate figure in determin- ing the : 408: Froth, The He of small bubbles of . ae .» 204 Geological Section _... re Vil —— abstract of proceedings ... xxi Gilgai country, The nature and origin of; with notes on quaternary climate 1) BOF Guthrie, F. B., A suggested ex- planation of allotropism based on the theory of directive valency ... .. 318 Haematozoa of Australian birds No. 2 Heating and antiseptic treat- ment, The effect of, on the solubility of fertilising in- gredients in soils ... .. 169 415 XXVI),.. ; Paau Hebblewhite, W. R., An auto- graphic air-flow recorder.., 258 J Jensen, Dr. H. I., The effect of Heating and Antiseptic treatment on the solubility of fertilising ingredients in soils .. 169 —— The river gravels ‘between Penrith and Windsor . 249 —— The nature and origin of Gilgai country; with notes on quaternary climate ... 337 —— The geology and petro- graphy of the Prospect intrusion 445 Jevons, H. S., The geology and petrography of the Prospect intrusion ... 445 Johnston, Dr. T. H, “Echino- rhynchus pomatostomi (n.sp.) a subcutaneous parasite of Australian birds .. EE — The Haematozoa of Aus- tralian birds, No. 2 . 415 K Kempsey district, Preliminary note on the geolcgy of ... 159 Knibbs, G. H., Studies in statis- tical representation: sta- tistical applications of Fourier series oa S10 Suicide in Australia: A statistical analysis of the facts... . 225 Laseron, C. F., Note ona new type of aperture in Conu- laria.. es . 247 Lectures, popular science iv, ix MM Mathews, R. H., Some curious stones used by the abor-: igines we. BOD Medal, Clarke, awards of ...XX1V Society’s, awards of .. XXV Melaleucas, On the Australian, and their essential oils; part iv , . 365 Members, deceased _.... iv, xxiv, l —— honorary vil, xxili Prick Members, list of... (xiii) —— newly elected ili, ix, xi, xii, XV, XVil N Nepheline-bearing rocks of the Liverpool and Mount Royal ranges, Ric tans note on the Sate .. 175 Nitrate figure, value. wat in determining the fitness of water for drinking purposes 408 Oo Obituary ... Bee aie XX1V notices bes ome ae 1 Officers Vil FP Pokolbin. The geology of the eruptive and associated rocks of _... Pollock, Prof. J. A., The origin of the small bubbles of froth 204 Popular science lecturesin1910 3 Presidential Address, Prof. T. W. E. David Se ae | Proceedings, abstract of Sesh Prospect intrusion, the geology and petrography of . 445 . 379 Quaternary climate, notes on 337 River gravels between Penrith and Windsor “ Rock specimens from Central and Western Australia,col- lected by the Elder Scien- tific Exploring ye of 1891-2 249 . 292 S Shellshear, W., Notes on trans- ition curves Smith, H. G., On some New England eucalypts and their economics ... —— Onthe Australian Mela- leucas and their essential oils, part iv. . 365 Statistical representation, Stu- dies in: Statistical appli- cations of Fourier series... 76 Stones, some curious, used by the aborigines . 359 61 267 XXVIil. PaGE Suicide in Australia: A statis- tical analysis of the facts Siissmilch,C. A., The geology and petrography of the Prospect intrusion .. 445 225 T Taylor, T. G., The geology and petrography of the Prospect intrusion Tectonic lines of Australia, 445 Paar Transition curves, Noteson ... 61 WwW Wearne, R. A., Notes on the Geology of "West Moreton, Queensland 137 West Moreton, Queensland, Notes on the geology of ... 137 Willis, Dr. C. 8S., The value of the nitrate figure in deter- mining the fitness of water Notes on some of the chief 4 | for drinking purposes ... 408 Thomson, J. A., On rock speci- | Woolnough, Dr. W. G., Notes mens from Central and on the Geology of West Western Australia, collec- Moreton, Queensland 187 ted by the Elder Scientific —— Preliminary note on the Exploring kk neta of geology of the Kou 1891-2 < .. 292 district se ap . 159 Sydney : F. W. Warirr, Printer, 344 Kent STREET. 1912, Plate I. uosuljoy'g“3"H Aq Smog pue sdew Uo peseg. LSC bh Aq pdyonaysuog— — oe ia : ore ee he e | *#euyy pues, Surmeys > : : WITVHLS AY yo dew sarjsy Journal Royal Society of N.S.W., Vol. XLV., 1911. Plate IL 150 RESS\CYORK TRAST Ik Marine Tert Cretaceous § | Trias-Jura.. sperieD (HEAVY FAULTS) Perma-Carbo Granite... lo : ar A\RNS ea w 2 z PROBABLE Fauurs x uder 7) bk < I, LENDEN KER S426rr , \ B 8 A y are Dy nie, MEE. TOWNSVILEE J Fe u Qa P4 3 q fe) So SABRISBANES 9 as Big? we .) H E C.Robinson. Delt. Society, N.S. Wales. Journal, Ro INDEX Marine Tertiary Cretaceous Basins d ’ fe ‘, Peiican tas ar Trias-Jura : “ey s Py Permo Carboniferous LENDEN KER S28+7 Granite SOUND FAULT AT STYx RIVER Town Re, Be SVILLEY Se 3 ae tt Re, we Macdonnell rR eh Ges ~‘ oe Capricorn o 3 ten DOWNTHROW Sou an “Orige RY « oF J “coy #2 eWowe TECTONIC FEATURES fret ae AUSTRALIA«*® TASMANIA. To illustrate Presidential Address &Y T.W. EDGEWORTH DAVID, 1911 A tate Scale of Statute Miles B_ Basset edges, or foliation of rocks: 100 2 = 090 Volcanic Foci Faults are specified as such | Yao" wonoes INDEX TO TECTONIC FEATURES HECRobunson. Delt. ff vr sen cthr ap * BA oa +> ra iia “. i m i * *E Ne ¥ if i oy ; aes ce res F 4 t Plate IIT. Journal Royal Society of N.S.W., Vol. XL V., 1911. ‘SOSURY SUIPIS oy} oe ‘oURASIP AVF UT “QJoT Oy} UG) ‘“puodog 9dURYSIP B[PpIUT OY) UI oTFOLpOO AA JUNOT! YAM ‘J[N-9 S,JUSOUI A “IQ JO Opis 1vou 94} UO dn Moys sosuey AQJoT JUNO] OY, ‘“SUITeD A¥aT 4SvOd 04-doeq4s 94} SI “4QYSIA OUIAI}xe 94} UD ‘seoURIIOA ABMEpUeNT OY} sozeoIput yeod dieys puooes oyy uUlese {YSTI 94} 09 pu 41 puUIYyeq soouKd JOA 9[Ssunquinase A, oy} Jo yvod dueys oy} YIM , 100004), JoJUNF{ OY} SI OYSNIOSOy Jo YSII 9Y4 09 Your 9UO ‘soulT puer) "AA pue ‘Wy pue ‘g pue ‘Ny 904} jo JuIod Sutyjouy 94} 9¥ OYsNIOSOY JUNO; puY ‘yIeIWQ sseq Jo YsnoIly WNT OY} JO FJoT 09 VIUEISeT, Jo .ysIOYy, oy} Sutmoys ‘otAqupoy_ “yy “AA Aq vluewsey, pue eljeiysny Jo japom jorjery . es a Uw ae 4 Ft pitas nia atric CRA RE tenia ante etn cen ee 2s a isin oe Journal Royal Society of N.S.W.,Vol. XLV., 1911. Plate IV. ‘qsvo oy} Worl dey s.meygsniuuny WO ‘peoy YOIMIV AM PIO Mos Plate IVa. ‘raays Joe; QO0'S ATAvOU VoVZ snozIdiosad vB SuIMOYS Yog s,1901dg Journal Royal Society of N.S.W., Vol. XLV., 1911. ‘ybnoujooy ‘4D ‘ff PUv ouwgway “p a—puvjpsusen’dy ‘uojauopy pe4y fo Abo70045 2y47 UC IQ} JUNO Tou Plate V. Sebast Jowrnal Royal Society of N.S.W., Vol. XLV., 1911. GEOLOGICAL SKETCH MAP of part of the MACLEAY RIVER DISTRICT Geological Boundaries are not accurate. Shading is diagrammatic and has no relation to strike of beds. Gees Limestone eral Glacial conglomerate Conglomerate. perhaps BELLBROOK glacial Tuffs and tuffaceous sandstone. The remainder of the area between Sherwood and Moparrabah ts occupied by slaty rocks. Plate V. J Journal Royal Society of N.S. W., Vol. XLV., 19117. Plate VI Journal Royal Society of N.S.W.,Vol. XLV , 1911. Plate VII. Pe fs i a)#) a v4 Journal Royal Society of N.S.W., Vol. XLV., 1911. Yj YW yi y y 7 q Plate VIII. Yj if} a | Wj y j Yj Yy Y) . 1% solution of acetic aci F Photographs of a bubble of CO, being formed in-— Journal Royal Society of N.S.W., Vol. XLV., 1911. Plate 1X. Photographs of a bubble of CO, being formed in = ~ S S JS ~ D S S . MW dD = = of oOo = ae (Ee >= a) S wD oN =) =n on 3 ; Journal Royal Society of N.S.W., Vol. XLV., 1911 Plate X. Photographs of a bubble of CO, being formed in iberceeeeny Hlodmenrenmrnaniipyyboenmmmmmme IIT // a sot sR) ~~ ° Ss on a2 ae a a S a) ~ S ‘ 3 ie) Sa Ss is = => O-1% solut he 5 4 7 a aa : | ” Ny en ied Sere “ly Journal Royal Society of N.S.W.,Vol. XLV., 1911. Plate XT, Fig. 1—Conularia cf. levigata, Morris. Lateral view of specimen, natural size, with portion near the aperture removed. ,» 2—The portion of Fig. 1, removed, showing the nature of the orna- mentation on the interior of the aperture. ,, 3—The same specimen. View of the aperture, showing the infold- ing of the walls. Journal Royal Society of N.S.W.,Vol. XLV., 1911. Plate XLT. 4 3 i : F z RECORDING PEN PAPER DRUM APERTURE PLATE ‘RECORDING DRUM FLOAT ZERO-LINE PEN DISCHARGE HOLES “CLOCK GEAR GAUGE GLASS AIR INLET THE AUTOCRAPHIC AIR-FLOW RECORDER. Fate, HLAB, bith ee OR Rc EUCALYPTUS CAMPANULATA, ATE, del ad nat — Ta Sp. NOv.. Plate XIV. Vol. XLV., 1911. ‘ mr) Journal Royal Society of N.S.W. Fig Fig. 6, Fig. & Journal Royal Society of N.S.W., Vol. XLV., 1911. Plate XV. Fig. 2—Sia Mayical Stones and Six Matchets. SATs SSE SS afte. AY pee eG B i ee 7 J ea ah, a AUAB: Sith. MELALEUCA GENISTIFOLIA, Sm.. "RI[OJIJSIUAS PONalRLVW ADIEU 2 'G ‘“SIy Plate XVII. @LU Ueerald Journal Royal Society of N.S.W.,Vol. XLV , 1911. Plate XVI/1. Journal Royal Society of N.S.W., Vol. XLV., 19/1. "eI[OJIISIues eonslejeaw Journal Royal Society of N.S.W.,Vol. XLV., 1911, Plate XIX. Fig. 4. x 450. Melaleuca genistifolia. ‘eBSOQQIs BoOnesTRIeIW ok 9 Fy Plate AO So pas 7S “BI[OJIISIUSS BONITO! ‘OFI xX "Gg ‘SIy Journal Royal Society of N.S. W., Vol. XLV., 1911. Plate XXI. Journal Royal Society of N.S.W., Vol. XLV., 1911. Or ~* ‘esoqqis evonsleleW "8 SL Journal Royal Society of N.S.W., Vol. XLV., 1911. Plate XXII. xe TO) 9 Melaleuca gibbosa. Plate XXIII. Journal Royal Society of N.S.W.,Vol. XLV.,1911. OF ‘eSOqqis PonelRelaWw fae) Re dapatilly a fet ee 4 + / ; cys ee ie » — Pa a 4 : ‘OTT Xx *eroyjroned wonelejea yw — zy] ‘Bua ISSAC Plates X XTV. hee “eSOqqIs vonelelaNW— II ‘sly Journal Royal Society of N.S.W., Vol. XLV., 1971. <0 5 SO SxS o. ERR o, S825 S25 Ce xX Plate XX V. Journal Royal Society of N.S.W.,Vol. XLV., 1911. SNIVHD Of i \ \ 39S . sauojspues pue sayesawo)3u05| Po Ss cM WE Wa AK \ SS KWL OQ KY sauospues perry . S2/PYS SajesawojJu0D 34149|09 SJOUTMNOWIVIONUTT "auoysyoyig E> y ‘eysepuy ==] ‘ausapuvdyoay FE == ALIAWO|IFe WuesX0, ha ©xesoourjay) arAyoos RSS nes909NA7) arAyorsy INS ayesoWO/Bae aHOAYY eed] suns pur awohves TTT a Morpourss [SG 1 MSN NIG1OX0d cy0N GALVIDOSSV B IAlLdNYA aMi 40 d¥W 191901039 ON3937 snouasiNoguvo Journal Royal Society of N.S.W., Vol XLV.,7911. Plate X XVI. . Z ah aalegecat %, a ee ‘ — S \ lege fe H \ ; ws aa ; . : \ 5 ‘ : i we pln pe ns ap rel et ee sal BBW®ye NOI, 4) ta A RS Ny Py g SS D = Ne S > ~~ OCVE Journal Royal 8 ers NG warn Heit ee ee Plate XO) aa Fig. 5. ety of N.S.W.,Vol. XLV.,1911. yal Soct Journal Ro Plate XXIX. ed les eyo Deed s/o Ps a7g o< : Cernelery THMATES LanwD TR ACeaCOUR SS “CLARA Typhot aL (Prev cases $40¢077 Thus @ lesshels a d G 4 We lis ” oN, oa Journal Royal Society of N.S.W.,Vol. XLV.,1911. Plate XXIX. \Z Facecourse Ag cu ——| 36 igs oe SS ee Wolir Typhord forercases shewrs Tha @ Cesseils e aya wells . w c TEMPORARY Common Journal Royal Society of N.S.W., Vol. XLV., 1911. Plate XXX. Plate XXXII. Journal royal Society of N.S W., Vol. XLV , 1911. Plate XXX TT. Journal Royal Society of N.S.W., Vol. XLV., 1911, x wPNy oe ee, . Ln Plate Ao op, y of N.S,W., Vol XLV.. 1911. Yociet Journal Royal = Plate XXXIV. =Ssivas— ———————— N x Q x x x . o x ~ x « x x ee % & 5 x x - x « x td a4 x * x x x « 4 x x x PEGS Rane x si x x x x xX « x Xx he x x x x x x x K x x s * i x Ses Che td fear 2 NW Xi peaches icy ie - E Shai Samet teeny 3 ter pe at LAH 4 Ag x _ T2A9]-898 Baogn jaay 997 — J wvNLVG < * a eas ss aT ae Sg ee ats eS = x al reas x « Bake as 393) 002 ‘oot oe D suivia “g ¥ 7% 70 31V9S dV ANIT NO NOILOEUS HOLANS AIVHS VLLVWYNVIM ee aLldd9 100 GF 4) suivad “OP ‘OT 31V9S 0 Suivi ‘SATVM HLNOS MIN NOISOULNI LOddSOUd x ta x. 4 aLIaIOd x od a ———S-—— 4 ae = = “MOAsasay 199ds0sg Dans | Plate XXXIV. Journal Royal Society of N.S.W., Vol. XLV., 1911. av95 §V ANIT NO NOILOIS HOLANS SAIS VLLVMVnviAN sunerioa 22} oe avas S31¥M HLNOS MAN NOISNYLNI LOadSOUd wi 10 d¥W 1V91ID010439 MIOAYISIN 19308080 Plate XXXV. gslede stixezed-oilisGD. -_— —= <_ ~——aeO— a ee ——_— — <— stixseed | nisV NOlEuS 192 19qq UJ . ; | otixeseed neni. SER tes a eenomeneecunss a bne Sond wrisuQ 16 ae NOisnyLl 4 eer a : : r Se ee og sae Plate XXXV. Bg Journal Royal Society of N.S.W.,Vol. XLV., 1911. ie ¥ i aN 4. ee. ing . ee us) g Y a er ‘ Plate XXXVI. Royal Society of N.S.W., Vol. XLV , 1911. Journal Plate XXXVII. Journal Royal Society of N.S.W., Vol. XLV., 1911, Ife AXVIT Plate XX Journal Royal Society of N.S.W., Vol. XLV., 1911. Aaa 5 a ‘ ; Plate XXX1X. Journal Royal Society of N.S,W., Vol. XLV.. 1971. val Sp aS & . ORS Journal Royal Society of N.S.W., Vol. XLV., 1911. Plate XL. Journal Royal Society of N.S.W.,Vol. XLV , 1911. Plate XL. . = Se eee Sl ‘ ae ) 1 ee ‘ 7 oi ; i ae A ice oul e | i ha i = ¥ rw 4 A | a q 1 fl aphii tt ; i DUE Ki : ; \ ~ 9 3 \ j Dont fit, : \ A \ i = A, Wel in \ ( il ‘at 5 : Vey Mi, J Eun i! Ay To Whe ae { { ' * i ' + ' \ | { i Bay ey | \ ) 4 { | hi us | f j i eer : af ui ” ' = 1 l nt i hk i j al of t . ; ee yy * le q \ \ i it \ i | ‘ ‘ i 1 i } j if | i F | luyy f | \ ‘ | i iy A A A [h, i in 3 9088