MINERAL RESOURCES. ' No. 24. THE MOLYBDENUM INDUSTRY IN NEW SOUTH WALES. Digitized by the Internet Archive in 2016 https://archive.org/details/molybdenumindust24andr Frontispiece. 5C5o NEW SOUTH WALES. Wvtnsrry V'Un OlSLl My i a . • 3 ^17 DEPARTMENT OF MINES. GEOLOGICAL SURVEY. J. E. Carne, F.G.S., Government Geologist. MINERAL RESOURCES. No. 24. THE MOLYBDENUM INDUSTRY IN NEW SOUTH WALES. BY E. C. ANDREWS, Geological Surveyor. SYDNEY: WILLIAM APPLEGATE GULLICK, GOVERNMENT PRINTER. t 68791— A 1916. [10s.] V h is 4 \£> C K. Ck.' Y.ft £uji. LETTER OF TRANSMITTAL. Geological Survey, Department of Mines, Sydney, 21st November, 1916. Sir, I have the honor to submit for publication Report, No. 24, of the Mineral Resources Series- on The Molybdenum Industry in New South Wales, by Mr. E. C. Andrews, B.A., F.G.S., Geological Surveyor. Molybdenum is much needed in the production of high speed steels, of steels of especial strength, of stabilizers for high explosives, and in other materials for munition purposes. j The molybdenite deposits of this State are highly important, being second in the list of the world’s producers of this mineral, Queensland being first. Although New South Wales exported only 32 tons of high grade molyb- denite concentrates during 1915, it is highly probable that the output could be largely augmented, as there are large low-grade deposits of promise in the State, which will probably be developed in the near future. Mr. Andrews’ work has been prepared with great care and thoroughness ; its appearance at the present time — when the demand is great, and the value high — should stimulate interest, and encourage development. I have the honor to be, Sir, Your obedient servant, JOSEPH E. CARNE, Government Geologist. The Under Secretary for Mines. 4 CN 374674 MAPS. # TO FACE PAGE 1. Localities in the State of New South Wales, in which the principal deposits of molybdenite occur ... ... ... ... ... ... ... ... 58 2. Sketch Map of Bolivia Granites ... ... ... ... ... Gt 3. The Kingsgate Molybdenite-Bismuth Pipes ... ... ... ... ... 94 4. Plans and projected Sections of Kingsgate Pipes ... ... 98 5. Tantawanglo Deposits ... ... ... ... .. ... ... ... 144 6. Sketch Plan and projected Sections of Whipstick Deposits 161 7. Sketch Map and Sections of Yethohne (Mount Tennyson) Deposits ... 174 PLATES. Frontispiece — Specimens of Molybdenite from Sachs’ Mine. PLATE TO FACE PAGE I. View of Treatment Plant belonging to “ Sachs of Kingsgate” Company ... ... ... ... ... ... .... ... 9 II. View of Treatment Plant at Irvinebank, North Queensland... ... 13 III. General view of three famous Molybdenite- Wolfram-Bismuth Mines in North Queensland, 1916 ... ... ... 14 IV. General view of Wolfram Camp, North Queensland ... ... ... 17 V. (a) Deep Sinking at Wolfram, 1913 18 (b) Murphy and Leisner’s Mine, 1913 ... ... 20 VI. Top Camp, Wolfram ... ... 22 VII. Stereogram Illustrating Occurrence of Pipes ... ... ... ... 57 VIII. (a) Black Range Deposits .. . ... ... 60 (b) Mount Momsen 60 VIII A. (a) Concentrating Plant at Queensgate Mine (b) Jackson’s Shaft, Queensgate Mine Black Range 62 62 IX. Sketch Maps of Bow Creek and Allies Mines X. (a) No. 25 North Pipe ... (b) Yarrow Creek ... 76 92 92 XI. Open Cut. No. 40 Pipe XII. (a) Open Cut of No. 1 and 9 Pipe ... (b) Lower Plant, Yates’ property XIII. Nos. 1 and 9 Pipe XIV. Sketch Plan of Face in No. 45 Pipe in 1905 XV. Goodwin’s Pipe XVI. Directions of various Pipes at Kingsgate XVII. Nos. 1 and 2 Pipes. M.L. 1, Kingsgate XVIII. Sketch Map, Moonbi Deposits XIX. Molybdenite Specimens, Warrell Creek XX. Sketch Map, Rocky River Deposits XXI. Sketch Map, Tantawanglo Deposits XXII. Sketch Map of Whipstick Area ... XXIII. Whipstick Mines XXIV. (a) Mount Tennyson and Macquarie Valley (b) Mount Tennyson from Wambool ... XXV. (a) No. 4 Open Cut (b) General view P.M.L. 12 ... XXVI. (a) Kirk and Wade’s Open Cut (b) Mount Tennyson XXVII. Wollastonite and Garnet. Yetholme XXVIII. Molybdenite with Quartz from Allies Mine, Deepwater 96 104 104 106 108 111 113 115 122 128 137 144 152 163 171 171 180 180 183 183 185 192 - > ■ FIGURES. FIG. PACF. 1. Staine’s Deposit, Maryland 28 2. Plan and Section of Pipes ... ... 42 3. Veins of Quartz in Granite Dyke 53 4. (a) and (b) Bald Nob Deposit 59 5. Ideal Section of Pipe at Bolivia (5 6. Sketch Section of Bottom in Murphy’s Pipe ... 70 7. Sketch Bow Creek Pipe 79 8. (a) Coronation Mine Section ... 80 (b) Sketch Map, Coronation Mine 80 9. Rummery’s Lease 83 10. Glen Eden Deposits ... ... 88 11. Ideal Section of Kingsgate Pipes 95 12. Sketch of Face of No. 40 Pipe in 1915 105 13. Sketch of Face in No. 40 North Pipe in 1915 105 14. The Reef Blow ... 107 15. Sketch of No. 45 Pipe Face in 1015... 110 16. Sketch Plan Wet Shaft 113 17. Maurer’s Claim, Yarrow Creek 116 18. (a) and (b) Sketch Map, Betts’ Deposits ... 124, , 125 19. Sketch Map, Warrell Creek Deposits 128 20. Sketch Section of Detail of Warrell Creek Reef ... 131 21. Sketch Map of Lode Hill 132 22. Sketch Map, Boundary ('reek Leases ... 138 23. Sketch Section of Reid’s and Adams’ Leases 138 24. (a) and (b) Sketch Sections, Boundary Creek 139 25. Idealised Section, Goodwin’s Pipe ... 140 26. Sketch Section of Face, Roberts and Heiss’ Pipe ... 142 27. Sketch Section across Whipstick Mining Area 154 28. Stalling’s Lode ... ... 169 29. Locality Map of Yetholme ... ... 170 30. Sketch Section, Yetholme Deposits 172 31. „ „ 173 32. ,, „ 174 33. „ „ 174 34. „ „ 176 35. ,, , , ... ... ... 176 36. „ „ 176 37. Sketches of Wollastonite and Limestone Nodules 177 38. Sketch Section of Detail of Yetholme Ore Deposits 178 39. 178 40. No. 4 Open Cut... 181 41. Sketch Plan, Borchardt’s Claim 187 42. Sketch Section, Borchardt’s Claim ... 188 43. ,, across portion M.L. 1 . 183 44. ,, across Cliff in M.L. 1 . 188 45. ,, „ ,, 188 1 687s)l -b TABLE OF CONTENTS. Letter of Transmittal I, Introduction and Summary ... ... Molybdenite Mining and Concentration only in the Pioneer Stages. II. Acknowledgments ... III. Properties of Molybdenum Minerals ... Molybdenum, Molybdenite, Molybdite, Wulfenite. IV. Uses of Molybdenum V. Technology of Molybdenum ... VI. Concentration of Molybdenum Ores VII. Regions of the World containing Molybdenite, with brief notes on their Geological Occurrence Canada, Norway, New South Wales, and Queensland, important producers. VIII. Production of Molybdenite in Australasia ... Almost entirely confined to New South Wales and Queensland. IX. General Geology of Molybdenite Deposits in New South Wales ... A. Granites Associated with Deposits (a) General type coarse, sandy, and granular (b) Wolfram Granite ... ... ... (c) Tin and Tin-wolfram Granites (d) Rocky River Granite... (e) Basic Granites These basis types always intimately associated with aplitic types where Molybdenite deposits occur within them. B. Types of Molybdenite Deposits in New South Wales (a) Pipes ... 1. Quartz Pipes 2. Pegmatite Pipes... ... 3. Granite Pipes 4. “Mica-Garnet” Pipes ... 5. “Garnet-pipes” ... (b) Pegmatitic and Aplitic Segregations (c) Pegmatitic Veins (d) True Quartz Veins ... ... ... ... 1 . In Marginal Areas of Granite within Greisen 2. In Tin-granites of Fiue Texture 3. In Coarse Basic Granites 4. In Sandy Granites Fine and Coarse in Texture 5. Networks of Veins in Quartz Porphyry (e) Contact Deposits containing Molybdenite Gemalla and Yetholme, Red Rock [and Duckmaloi ?] Com- parison with contact deposits recorded from Queensland and Canada. X. Notes on the Prospecting and Mining of Molybdenite Deposits ... Mainly found in coarse, sandy granites, near intrusive junction with other rock types. Occur mainly as pipes which have tortuous directions. Mining and development costs therefore heavy, especially as pipe dimensions are generally small. Con- centration is only in pioneer stage. (a) Prospecting Pipes ... (b) „ Xrue Veins (c) „ Pegmatitic, Aplitic, and Graphic-granite Segregations (d) General Occurrence of Ore Deposits in connection with Prospecting PAG*. iii 1 3 5 7 8 9 14 22 23 23 23 24 25 26 26 26 26 27 32 34 34 34 34 34 35 35 35 35 36 36 . 37 40 42 48 51 53 PAGE. Xll XI. Description of Deposits, and List of occurs in New South Wales.. Ardlethan Deposits Bald Nob Bathurst ,, Bega ,, Black Range ,, Bolivia ,, Appleby’s Deposit .. Cooper’s Pipes Fletcher’s Claim ... Horseshoe Bend ... Key’s (E. L.) Claim Key and Parry’s Claim ... Kiernan and Party’s Claim Murphy’s (E. W.) Claim... Wayne and Hamilton’s Claim Other and smaller Deposits Booroolong Deposits ... McKinley’s Claim... Macpherson’s Lease Robertson’s Claim... Schaefer’s Lease ... Wiidblood’s Claim Snape’s Authority... Stanley’s ,, Botobolar Deposits Brewongle. Broken Hill Bullin Flat... Burro wa ... Capertee ... Captain’s Flat Carcoar ... Carrai Cleveland Bay [?] Deepwater Deposits ... Allies Mine Bow Creek Mine Coronation ,, Ford and Barnett’s Claim Rummery's Claim... Delegate Deposits Diehard ,, .. Drake ,, Eden ,, ... Glen Eden ,, Baker’s Hill Deposit Glen Eden Mines ... Glen Elgin Deposits McDonald and Yuen’s Claim O’Keefe’s Claim Pheasant Creek ... Goodrich Deposits (few flakes) Goulburn ,, Captain’s Flat, Jerrabat Gully Towrang (Ludwell’s Claim) Gulgong (few flakes) ... Guy Fawkes Deposits ... Serpentine River ... Keaton and Cuskelly’s Claim Logan and Party’s Claim Holbrook Deposits Kempsey (few flakes) ... Kiandra ,, Localities in which Molybdenite ez A 58 58 f 8 6 !) CO 60 G3 64 65 67 67 67 68 69 69 70 70 71 71 71 71 71 72 73 73 73 73 73 73 73 73 73 73 74 74 74 75 76 SO 81 81 83 84 84 84 85 86 87 88 88 88 89 89 89 89 89 90 90 90 91 91 >endix. 91 92 Xlll XI. Description of Deposits, and List of Localities, &c. — continued. Kingsgate Deposits Kingsgate Proper Yates’ Pipes (with Schedule of Deposits, pp. 101 hnd (1) Arsenic Blow (2) Black Shaft ... (3) Forty (4) Forty North (5) Granite Pipe (6) Mount Morgan ... (7) One and Nine, or No. 5 (8) Reef Blow (9) Tin Shaft (10) Twenty-five North (11) Wolfram Blow Block 45 (1) Old 45, or Sachs’ Pipe (2) Monkey Shaft Sachs of Kingsgate Syndicate (1) Goodwin’s Shaft (2) Prospecting Area ... (3) Wet Shaft (Water-Cut) Speckhardt and Party (1) M.L. 1 Lancaster’s, O’Donnell’s, and smaller claims Y arrow Creek ... Maurer’s Claims Other smaller claims... Laura Creek Deposits ... ... Spencer’s Claims ... Llangothlin Deposit ... Manildra Deposits ... Higman’s Authority Lennan’s ,, Moore’s ,, Mann River Deposit ... ... Marulan Deposit Mole Tableland Deposits ... Taylor’s Lodes ... ... Walker’s Claim ... ... ... Watkin’s Claim Moonbi Deposits A. Attunga Deposits B. Moonbi (proper) Betts’ Claims Russ and Edwards’ Claims... Nambucca Deposits Kritsch’s Claim McLeod’s Claim ... , Myra- Lucy Claim Parker’s Claim ... Sutherland and Party’s Claim ... ... Nymagee Deposit ... ... ... ... Oban Deposit ... Lowe’s Claim ... ... ... ... Oberon Deposits ... A. Duckmaloi River Dwyer’s Claim Kirk’s Claim ... B. Lowther ... ... Webb and Party’s Claim Orange Deposits (small) Pambula. (Note by Rev. W. B. Clarke> t 68791— c 12 ) PAGE. 92 103 103 103 103 104 104 105 106 106 107 107 107 108 108 108 111 111 111 111 112 113 113 114 115 115 115 118 118 119 119 119 119 119 120 120 120 120 121 122 122 122 122 123 126 127 129 129 130 130 131 132 132 132 183 133 133 133 133 133 134 134 XIV XI. Description of Deposits, and List of Localities, &c. — continued . Rocky stiver, or Wunglebung Deposits A. Boundary Creek Adams’ Claim Reid and Weir’s Claim P. Wunglebung ... Goodwin’s Claim Petrie’s (John) Claim Petrie’s (W. F.) Claim Roberts and Heiss’ Claim Vaughan’s Claim. ... Other and smaller c-laims Skeleton Creek Deposits (small) Tantawanglo Deposits ... Clarke’s Claim (Packer’s Swam Fisher’s Claim ... ... Fulton’s Claims Hammond’s Claim Jessop’s Claim Knox (T. and P. J.) Claims Summerell’s Claim Tarlington’s Lease Taylor and Adams’ Lease Tenterfield Deposits Chorley’s Claim (Bungulla) Donaldson’s Claim (Bungulla) Other and Smaller Deposits Tingha Deposits Elsmore Deposits (small)... Howell Middle Creek Whipstick Deposits Mount Metallic Mine, Mount Metallic Pheasant’s Nest, Whipstick Mines, Ltd Young and Reid’s Claim Wilson’s Downfall Deposits Flint’s Vein Fordham’s Vein ... Gunn’s Authority... Martin’s Authority Staines’ Lease Stalling’s Lease Sugarloaf Mountain Waterson’s (John) Claim, Maryland Waterson’s (J. F.) Claim Yarras (Flakes recorded) Yetholme Deposits A. Mount Tennyson Deposits ... Boyds’ Blocks, Boyd’s Molybdenite, Yetholme Mines. Buekridge’s Block (P.M.L. 12), Boyd’s Molybdenite Yetholme Kirk and Wade’s Molybdenite Mines Kirk’s (Z) Block or Lithgow Company’s Field and Garrard’s Blocks Yetholme Molybdenite Options, Ltd. Other and Smaller Deposits B. Gemalla Deposits Reakes’ Block ) Slade’s Block > Described together Tonkin’s Block ) C. Tarana Deposits Borchardt’s Claim ... Railway Cuttings, near Tarana XII. Future of the Industry Appendix Blocks PAGE. 135 137 137 138 140 140 140 141 141 142 142 143 143 145 145 145 145 145 145 146 146 146 147 147 147 147 148 14S 149 149 150 161 161 162 166 166 166 166 166 167 167 167 167 168 169 170 170 179 179 ISO 181 182 182 183 183 183 184 186 186 187 190 192 The Molybdenum Industry in New South Wales. I.— INTRODUCTION AND SUMMARY. The molybdenite industry, especially in regard to the treatment of the ore, is only in the “ pioneer ” stage, and it is felt that the present report may be useful as a signpost to indicate the phase which this important industry has reached. It is recognised also that the report may be regarded as antiquated within a few years, owing to the rapid improvements being effected in the treatment o-f the ore. The fact itself that customs works charge from £1 10s. a ton upwards for the treatment of concentrates, even with oil flotation, shows that much remains to be ascertained in the way of simpli- fying the process. Nevertheless, it seems advisable to co-ordinate our present knowledge, so as to place the main facts connected with the industry before the mining community, so that the various deposits of the State may be viewed in the one perspective. The better to show the position or niche occupied by New South Wales in the Molybdenite Industry of the world, a special chapter has been inserted concerning the main occurrences of molybdenite throughout the world. Further reference may be found in the chapter on the outlook for the industry. General . — It is now many years since the pioneer work of Clarke, Daintree, and Wilkinson showed the intimate relation of the valuable mineral deposits of the plateau and coastal provinces of Eastern Australia to the great masses of granitoid rocks forming the buttresses of the plateaus therein. Some of these occurrences are very large, some small, seme are dark in colour and contain much hornblende and black mica, some are coarse in texture, granular or porphyritic in texture, many again are fine in texture and of granular habit and are composed essentially of small grains and crystals of quartz and felspar, well interlocked. It is coming to be known generally that these types occur together in many large areas, the dark types being the oldest, while those of fine texture and a high proportion of silica content, seen in nature as an abundance of sand grains in the rock, are the youngest or intrusive members of these granitoid assemblages. In general the darker, that is the more basic, types, are associated with gold and copper deposits; the coarse, sandy, and granular types with molyb- denite and bismuth (in New South Wales) ; while the very sandy types, which form striking topographic features in the landscape by reason of their resistarce to the agencies of denudation, are characteristically associated with tin and wolfram, especially with tin in New South Wales. The latter types where carrying tin deposits of importance, contain molybdenite in flakes well scattered, but not of commercial importance. In southern New South Wales these granitoids may be closing-Devonian in age, while they appear to be of late or closing-Permo-Carboniferous age in New England and in North Queensland. t 63791— A 2 Around the margins of the coarse sandy types, especially in New South Wales, molybdenite and bismuth deposits occur, and with them wolfram may occur rarely. These deposits occur in the coarse granite, generally as pipes of quartz or granitic material. An exception to this rule is to be found at Yetholme, in the Bathurst district, where the molybdenite occurs as .a contact deposit associated with limestone, claystone, and quartz porphyry near sandy granite. From time to time deposits of molybdenite, hitherto unknown or unpros- pected, are reported from the margins of certain coarse and sandy types of granite, and it is hoped that the publication of this report may be useful in directing further attention to these granite masses of the Bolivia, Booroo- long, Deepwater, Monaro, Moonbi, Rocky River, Tenterfield, and other areas, prospected as yet only in part In the report also is implied the advisability of mapping and classifying the composite granitoid masses in New South Wales. 3 II.— ACKNOWLEDGMENTS. The list of the names of all those who have supplied information for the preparation of the present report would he a very long one, and only those who have supplied information of major importance are here mentioned. Mr. W. H. Yates, of Bondi, has supplied the luminous notes from which the history of the Kingsgate field has been prepared, and every facility was afforded by Mr. Yates for the inspection of the very numerous and important deposits known as Yates’ Pipes. Mr. Wm. Marshall, and his brother, Mr. H. Marshall, have a first-class knowledge of the local conditions of mining at Kingsgate, and to their kindness in supplying notes on mining at Kingsgate the report on Kingsgate owes very much of any value which it may have. To Miss P. Speckhardt the writer is indebted for assisting in making the survey of the Kingsgate properties, outside those belonging to Mr. Yates, as complete as possible in the limited time at his disposal. To Mr. D. Munro and Mr. Hagen are due the notes on the Old 45 or Sachs’ Mine. To Mr. T. Schafer, of Whipstick, cordial thanks are due for showing the writer many spots of geological interest at the Whipstick Mines. Cordial thanks are due also to Mr. Schafer, Mr. J. Scantlebury, and Mr. H. Robertson, for information concerning the Whipstick Mines, Ltd. To Messrs. J. H. Fawcett, F. Cape, W. L. Garrard, H. Marshall, and Mr. Bethell, cordial thanks are due for general information concerning the interesting Yetholme deposits. To Messrs. E. W. Finch and A. Pedley are due the notes on Bow Creek Mine, and for general information on molybdenite mining. To Mr. A. Collins, of Deepwater, cordial thanks are due for conducting the writer to numerous molybdenite deposits at Deepwater and Bolivia ; to Mr. E. A. Baker also for information regarding the Allies and other mines. Cordial thanks also are due to Messrs. Frank Roberts and F. Heiss for information concerning the Rocky River deposits; to Mr. Percy Reid for conveyance to the Wunglebung deposits; to Messrs. Percy Reid and Hughie Weir for information concerning the remarkable Boundary Creek deposits; to Mr. Betts for conveyance to the Haystack Mountain, and information concerning same; to Mr. A. E. Cooper in connection with certain Bolivia, deposits; to Messrs. Cadogan, T. Betts, and Russ in connection with the Moonbi deposits ; to Mr. W. Balmain for conveyance to the Tantawanglo deposits, and to Messrs. Bush, Knox, and Fulton in connection with these deposits; to Messrs. Edwards, Jackson, and Wachman in connection with the Black Range deposits, and to Mr. H. H. B. Deane for conveyance to the Wymah deposits. A joint inspection of Yetholme was made by Mr. J. E. Carne, Government G;olog’st, and the Writer, in June, 1915, while notes on the Nambucca or Warrell Creek field have been supplied by Mr. Carne. Notes on various districts and deposits have been supplied by colleagues, especially on the Carrai, Manildra, and Serpentine or Guy Fawkes areas, by Mr. M. Morrison, on the Warrell Creek deposits by Mr. J. R Godrey, on the 4 Holbrook and Wymah deposits by Mr. H. Hooke, on the Bega and Delegate area by Mr. D. Milne, on tlie Monaro area by Mr. Leo. Jones, on the large New England area by Mr. George Smith, and on the Western District by Mr. J. Cart hew. Lists of occurrences were supplied by the various Wardens, and many places were shown to the writer by Mr. Warden Perry, in whose district the great bulk of the deposits occurs. Plates II, III, and IV have been reproduced through the courtesy of Mr. C. Y. Caird, of Sydney, by whom the original photographs were taken in North Queensland. Plates Y and VI have been reproduced from Mr. L. C. Ball’s negatives by the courtesy of the Queensland Department of Mines and the Editor of the Queensland Government Mining Journal. Plates I, XII, XVI, and XVIII have been reproduced from photographs kindly supplied by Miss Speckhardt. Plates XXV, XXVI, and XXVII have been supplied through the kindness of Mr. Fawcett. Plates XIV and XXIV have been reproduced from Mineral Resources , 1901, by Mr. E. F. Pittman; and Plate VIII Fig. (b) has been reproduced from the Annual Report of 1897, from a section taken by Mr. J. E. Carne. The diagrams of the Wet Shaft, Goodwin’s Pipe, No. 3 Pipe, on M. L. 1 and Nos. 5 and 25 North Pipes, all at Kingsgate, have been reproduced from figures courteously supplied by Mr. Leo Cotton, Acting-Professor of Geology at the Sydney University. The numerous plans, maps, and figures illustrating the report have been prepared by Mr. 0. Thicket t ; some of the figures being prepared from the writer’s measurements by Mr. Kenny, Field Assistant. The analyses of rocks were prepared at the Departmental laboratory under the supervision of Mr. J. C. H. Mingaye, and the petrological notes were supplied by Mr. G. W. Card, Curator of the Mining Museum. Magnificent specimens of molybdenite have been donated to the Mining Museum at the request of the Curator and other officers of the Survey and Inspectorial Branch, ana these specimens should be studied by all prospectors of molybdenite, who might thus save themselves much needless expenditure of time in the prospecting of insignificant deposits. Among the finest of these exhibited may be mentioned the donations of Mr. V. Sachs and Miss Speckhardt (from Kingsgate), of Mr. W. H. Yates (from Kingsgate), of Messrs. Hollibone and Parnell (Warrell Creek), of the Whip- stick Mines Ltd., of the Yetholme Molybdenite Options, and of Messrs. Boyd Bros., of Mr. Wm. Murphy (Bolivia), of Mr. A. E. Cooper (Bolivia), of Messrs. F. Roberts and F. Heiss (Wunglebung), of Mr. V. Schafer (Booroolong), of Messrs. Baker and Chalmers (Glen Eden), of Messrs. Pedley and Finch (Bow Creek), of Mr. E. A. Baker (Allies Mine), and others. 3 III. — PROPERTIES OF THE MOLYBDENUM MINERALS AND ORES. Molybdenum is a white metal with a specific gravity of 9. It is malleable and may be both welded and polished, but it is fused only with great difficulty. It has not been found in the native state ; but appears to have been isolated for the first time by P. J. Hjelm, who, according to the “ Encyclopaedia Britannica ” (11th ed.), in 1782 distinguished the mineral molybdenite from lead ore, with which it had been confused previously. Hjelm, also, is said to have discovered the element molybdenum in this mineral. Ores of Molybdenum. (1) Molybdenite . — The crystals of this mineral are hexagonal, and tabular in form. They may occur also as short and stout prisms with horizontal striations. It occurs, also, in the form of thin plates, masses, or scales, also as grains. Crystals, or massive forms, are separable easily into thin plates in a direction parallel to the base of the crystalline form. The thin plates thus obtained are very flexible but not elastic, that is, they may be bent readily in any given direction, but they do not spring back to their original positions, as micas generally do, when the pressure is released. The mineral may be cut easily with a knife. Its hardness on Molds scale, is from 1 to L5, that is, it may be scratched quite easily with the finger nail. The weight of a given volume of the mineral is from 4 - 7 to 4*8 times that of an equal volume of water. The lustre is metallic; the colour is lead-grey, and a bluish-grey streak is obtained by rubbing the mineral on white paper. It is opaque, and has a greasy feel. Its chemical composition is bisulphide of molybdenum, written MoS 2 , by which is meant tliat the smallest portions into which molybdenite may be broken without altering its nature entirely would contain each one atom or particle of the metal molybdenum, to which two atoms of pure sulphur would be found clinging. In pure molybdenite there is only 60 per cent., by weight, of molybdenum, the remaining 40 per cent., by weight, con- sisting of sulphur. It has a striking resemblance to graphite, both in softness and general appearance, but it produces a bluer mark on paper, and yields sulphur when burnt on charcoal. (2) Molybdite has a chemical composition known as molybdic acid or oxide, which is written in the form Mo0 3 . By this chemical formula the idea sought to be conveyed is that the smallest portions to which molybdite may be broken without altering its chemical nature would each contain one atom of molybdenum with three atoms, or particles, of oxygen gas clinging to it. This formula also indicates that in molybdic acid the molybdenum is present to the extent of 67 per cent, by weight, and the oxygen 33 per cent, by weight. It is a straw-yellow mineral, which occurs both in tufted, hair-like masses, and as yellow earthy incrustations associated with the brilliant faces of the molybdenite. (3) Wulfenite is another molybdenum mineral found in many parts of the world. It occurs also in New South Wales, but is a mineral of rarer occurrence than either molybdenite or molybdite. It is a molybdate of lead, which fact 6 is expressed in chemical notation by the formula PbMo0 4 . In this mineral each particle of lead is associated with one of molybdenum, while to them four particles of oxygen gas cling closely. The mineral is, however, fre- quently impure, containing admixtures, in such cases, of calcium, chromium , and a rare metal called vanadium. It occurs generally in squarish tables, also in massive form. Its hardness on Moll’s scale is 2-75 to 3 0, that is, it is just too hard to be scratched with the finger-nail, but is readily scratched with a knife. It is a heavy mineral, being nearly 7 0 in specific gravity. In colour it varies from yellow to orange, yellow and red ; it may also be dark dull green, brown, or almost colourless* The' streak is white. The mineral is brittle. 7 IV.— USES OF MOLYBDENUM. The salts of molybdenum, in the forms known as ammonium molybdate and molybdic acid, are used in chemical laboratories, to form blue pigments in the manufacture of porcelain, to dye silk and woollen goods, and to aid in the colouration of various leathers and rubbers. In the manufacture of -steel in the United States, several tons of molybdenum are used annually in the form of ammonium molybdate as a chemical reagent for the detection -and determination of phosphorus in steels. Ammonium molybdate is also reported to be much in demand for fire-proofing purposes, also as a disinfectant for cloth used in passenger carriages on railways. An important use to which molybdenum compounds may be put is the mixing of same to form stabilisers for high explosives, their presence prevent- ing both deterioration under moderate temperature, and premature explosion in these otherwise unstable compounds. The great use, however, to which molybdenum is put is in the manufacture of certain steels, as a substitute for tungsten, especially in self -hardening .steels, in armour, guns, and other steels needing tenacity and hardness Robert Forrester Mushet, in England, about the year 1858, found out that the introduction of the element tungsten into steel produced a remarkable result in the quality of the resultant product. He experimented on this product till about 1870, and a few years later the old Mushet self-hardening steel was produced, which contained about P85per cent, carbon, 9 per cent, tungsten, and about 25 per cent, manganese. In 1900, the University of Sheffield discovered that the elastic limit of steel could be almost •doubled without unduly sacrificing toughness and ductility by adding to this Mushet steel a relatively small quantity of vanadium. “ By reducing the carbon in the original Mushet steel frem 1-8 to 1-7 per cent., much increasing the tungsten and chromium, largely reducing the manganese, and adding 1 per cent, vanadium, the thermal stability of the cutting hard- ness was easily doubled, rising from 300° C. to well over 600° C. In fact, .such steel can be run for several minutes cutting cleanly at a red heat.” 2,500 0 0 5,250 0 0 437 10 0 175 0 0 131 5 0 2,200 0 0 ,675 0 0 ,000 0 0 500 0 0 Total estimated cost, £67,000. £66,868 15 0 The 21,000 tons of ore may be expected to yield -72 per cent, by weight of molybdenite, or 15,120 units, which at £4§ a unit yields £70,000 approximately, thus indicating a slight profit on the undertaking, but indicating none if the usual 10 per cent, margin be allowed for safety. This calculation is intended only as a guide, and does not pretend to be complete, inasmuch as certain unwarrantable assumptions have been made, and, moreover, certain necessary costs have been neglected. The unwarrant- able assumptions in the above calculation are : — 1. The assumption of control of all these pipes without payment by the owner of the plant. 2. The assumption, as an alternative to No. 1 assumption, of a guarantee, on the part of the owners or lessees of pipes, of the ore quantities necessary for a continuous running of the plant at full capacity. If the owner of the plant wished to secure the control of the pipes them- selves, it is almost certain that the former holders would not sell their rights under many thousands of pounds. If, on the other hand, he should depend upon the individual pipe owners for supplies of ore, each pipe being small, he must then depend, as a rule, upon the goodwill and the physical strength of the lessees as his only guarantee for supplies. For example, the individual small miner holding the lease of a “ pipe ” may wish neither to work continuously nor at high pressure ; he may fall sick, or he may be discontented with results and may refuse to supply more ore. The mill owner would expect also to lose much time, and thereby increase his costs greatly, by treating small parcels from each pipe separately. The assumption of a supply of ore sufficient to keep such a plant running for twelve months is a most risky one. The only localities where an amounl such as this may be expected with any show of reason are Kingsgate (Yates’ properties), Whipstick, and Yethohne. Yetholme deposits, however, are not ‘‘pipes.” In a case where a plant cannot be run continuously, or at its full capacity, the venture must end in great financial loss. 48 In the next case, suppose the ore to contain 2 per cent, molybdenite. Then, on the assumptions as above, a good profit is indicated. The only safe method, however, for the prospector to adopt in the early stages is to concentrate the crude ore in a moderate degree by hand-picking or with inexpensive machinery, and to send H to one of the several purchasers or concentrators of such ores in the State. Conclusion— Having regard to these various estimates, it is extremely doubtful whether a prospecting party could work a pipe from 3 to 6 feet diameter, and containing only 1 per cent, molybdenite, at a profit, even provided the ore be free from impurities, such as pyrites, zinc, lead, or copper. Pipes may be of pegmatite, of very siliceous granite, of garnet and quartz,, or of micaceous material containing quartz. These formations have direc- tions and size very similar to those obtaining in quartz pipes, but they are much more difficult, hence more expensive, to prospect, because of the distinctive appearance of the quartz in a granite setting as compared with the granitic and finely- textured pegmatitic gangues, which are not decidedly distinct as compared with the siliceous granite country. ( b ) Prospecting True Veins containing Molybdenite. Quartz Veins . — True veins of quartz containing molybdenite have been found and worked at Moonbi, Black Range, near Bega, Warrell Creek near Macksville, Oban in New England, and at the Haystaok Mountain, 17 miles south-east of Bonshaw. These veins are as well defined as true gold-quartz lodes, and the prospector of gold-quartz lodes would experience very little difficulty in exploring such deposits. The prospector of gold veins, however, is likely to be misled by the molybdenite contents. Being accustomed to prospect for gold in quartz he is inclined to over-estimate the amount of molybdenite present. Let it be assumed that the quartz vein can be traced for 400 feet along the surface, that the vein has an average width of 18 inches, that the gangue is clean, and that the mine is 350 miles from a port, 330 of which are by railway and 20 by road, the last 4 miles being across hilly and rugged country, so that the freight by team is, say, £2 10s. a ton. First — that the ore contain 1 per cent, molybdenite, and that it be hand-picked to 5 per cent, molybdenite, with a recovery of 80 per cent, of this mineral. Second — that the ore contain 2 per cent, molybdenite and be picked to 5 per cent, molybdenite. Both of these products are assumed to be despatched to Sydney. Third — that the ore contain 1 per cent, molybdenite and be treated at a local plant after being picked to 4 or 5 per cent, molybdenite. Fourth — that the ore contain 2 per cent, molybdenite and be treated at a local plant after being picked to a 4 or 5 per cent, standard. 1. This is the case of a vein of quartz 18 inches in width and containing 1 per cent, molybdenite. In a case such as this the surface indications, namely, the persistent and well-defined outcrop of a vein with definite walls for a horizontal distance of 400 feet, are extremely favourable for the expectation ot continuation of the 49 vein to a considerable depth from the surface. The reason for this belief is supplied on a subsequent page. Mining work may in this case, therefore, be laid out in advance with a certain measure of confidence, in striking contrast to the slow, laborious, uncertain, and expensive, methods of mining necessary in working “ pipes ” of ore. As in gold, silver, copper, lead, and zinc lodes, it is probable, in the highest degree, that the molybdenite occurs in shoots, occupying, say, only a portion of the vein or lode. In this case, however, it is assumed that the wein has an average content of 1 per cent, molybdenite. Suppose the vein to be developed by the sinking of two shafts 200 feet apart, and that two levels be driven on the vein, one at 100 feet and another at 200 feet, below the surface, and that the drives extend along the whole 400 feet of vein. Then the average cost of sinking the shafts may be estimated at £3, and the cost of driving at £2 a foot. The total cost of development may be put down at £2,800, and the cost of stoping and raising the ore may be estimated at £1 a ton. The total weight of ore in the block worked may be estimated at 9,250 tons, which has cost £2,800 for development and £9,250 for mining, or a total of £12,000 approximately to raise it to the surface under the most favourable circumstances, namely, the uninterrupted and continuous nature of the work, thus dispensing with the heavy cost of intermittent working, the heavy interest charges against capital, and the depreciation of machinery through lack of use. If the ore be picked to 5 per cent, molybdenite for a recovery of 80 per cent., then 6J tons of crude ore need picking to secure 1 ton of 5 per cent, concentrate, that is, the mine may be assumed to produce about 1.500 tons of 5 per cent, concentrate. The picking of this ore may be put down at 5s. on each crude ton or about 30s. on each ton of concentrate. The carriage on each ton of concentrate is assumed at £2 10s. to the railway and about 14s. by rail. Bags and bagging may be put down at 6s. a ton of concentrate, while carriage, sampling, and assaying, and so on, in Sydney may be taken at 15s. a ton of concentrate. It is probable that the most favourable terms upon which this 5 per cent, concentrate could be sold in Sydney would be £2 10s. a unit, or treatment at £4 10s. a ton, no impurities such as bismuth being present. A table of costs may now be presented. Mining and development on 9,250 tons Picking of 9,250 tons, at 5s. a ton ... Carriage of 1,500 tons concentrate to rail, at £2 10s. a ton Railway freight on 1,500 tons concentrate at 14s. Bags and bagging on 1,500 tons concentrate, at 6s. Sampling, assaying, &c., in Sydney, at 15s. a ton on 1,500 tons £ s. d. ... 12,000 0 0 ... 2,312 10 0 ... 3,750 0 0 ... 1,050 0 0 ... 450 0 0 ... 1,125 0 0 Total costs £20,687 10 0 Total value estimated — 1,500 x 5 units = 7,500 units, at £2 10s. = £15,000 + £3,750 = £18,750 0 0 Showing a great loss on transaction. If, however, the concentrate be treated for £4 10s. a ton for a recovery of 90 per cent, of the molybdenite and then be sold for £4| a ton, we have as before £19,562 for expenses to mill in Sydney, and to this must be added £1,500 x 4| for treatment, or £6,750, or a total cost of £26,312. On the credit side we have £1,500 x -9 x 4f x 5 = £31,500. 50 There is here an apparent profit shown, but it must be remembered that the customary practice is to make a 10 to 25 per cent, addition to the costs as a margin of safety. If this necessary precaution be taken, no margin of profit is revealed. In the second place, assume the ore to contain 2 per cent, molybdenite. On this basis a handsome profit is shown after hand-picking to 5 per cent, and paying for concentration in Sydney. On the third assumption a plant for the recovery of the ore is to be erected by the prospectors. The cost of the plant may be assumed as before. The accompanying table of costs furnishes some indication of the cost of mining and treating Gre containing 1 per cent, molybdenite. Mineral separation treatment is assumed. Mining and development on 9,250 tons Picking 9,250 tons to 6 per cent, molybdenite, at 5s. a ton Power on concentration of 1,500 tons, at 2s. 6d. a ton ... Labour, repairs, oil, &c., about Royalty, 5 per cent, on 1,500 tons of ore yielding 4*5 per cent. molybdenite ... ... ... ... ... ... Transport, sampling, assaying, &c., on 75 tons of 90 per cent, concentrate, say £ s. d. 12,000 0 0 2,312 10 0 187 10 0 1,000 0 0 1,575 0 0 250 0 0 £17,325 0 0 Total estimated value of contents recoverable is 75 X 90 x £4f = £31,500. And this shows a large margin of profit. Or, again, a plant for dry crushing and screening may be assumed. The cost of the plant may be estimated at £1,200, and the cost of working same at 15s. a ton. The ore may be assumed to be picked to 3 per cent, at 5s. a ton for a recovery of 80 per cent, of the material, and the fixed loss by the treatment in the plant may be assumed with some degree of confidence at •60 or -75 per cent, molybdenite, say -75 for purposes of computation. The grade of the concentrate may be taken at 90 per cent, molybdenite. Table of Costs. Mining and development on 9,250 tons Picking 9,250 tons, at 5s. a ton Treatment of 2,450 tons, at 15s. Cost of plant ... Bags, bagging, transport, &c., on concentrate, say £ s. d. ... 12,000 0 0 ... 2,312 0 0 ... 1,837 10 0 ... 1,200 0 0 ... 300 0 0 £17,649 10 0 Theoretically it might be considered that 5,550 units at £4§ a unit are obtainable as the result of this form of treatment, whereas in actual practice there are losses other than in the tailings, inasmuch as there is a double product from the screens, one a rich concentrate exceeding 90 per cent, molybdenite, and another which may be 40, 50, or 60 per cent, molybdenite. It would appear thus that the treatment by M.S. plant and sub-aeration machine would be the better process. In the case of a reef, 18 inches in width and averaging 2 per cent, molybdenite with treatment assumed as above, a magnificent profit would be indicated. The main point to be kept in mind, however, is that no lodes such as these are known definitely in New South Wales, Indeed, no lodes are known which have been proved to yield 500 tons of 2 per cent, ore to the present. TheBega 51 reefs are possessed of long and well-defined outcrops; their walls are well defined; they doubtless contain very large bodies of quartz; nevertheless prospecting is still at a stage so early that it is impossible to make any safe calculation as to the possible molybdenite content of, say, even 1,000 tons of ore. All that can be said with regard to these lodes is that the indications are very favourable as regards the expectation of fairly large bodies of quartz containing so-called “ payable ” molybdenite, Until such time as a large tonnage of ore reserves has been actually developed it is inadvisable to erect a treatment plant, inasmuch as the cost of same has to be charged against the ore. If that ore be 5,000 tons the erection of a local plant is imperative ; if it be 1,000 tons of 1 per cent, ore the erection of the plant is inadvisable ; if the ore be 2 per cent, the erection of the plant is advisable; if only 100 tons either 1 or 2 per cent, in grade, the erection of a plant is suicidal. Nevertheless, people appear to build plants with eagerness before there is any actual guarantee of ore existing in the veins or pipes. It cannot be stated too often that the cost of a plant of any service whatever would swallow up the profits from many tons even of rich ore, let alone low-grade material Pegmatite Veins . — These have the general form of some quartz veins, but may consist of a quartz matrix in which felspar crystals are irregularly scattered; they may consist of quartz veins containing large segregations of felspar crystals; they may appear as quartz veins in which only a few felspar crystals occur, or they may occur as large interpenetrating crystals of felspar and quartz, with or without mica plates. In New South Wales these pegmatite veins are generally very small and of very limited extension in length, width, and depth. The largest one known to the Writer is the Coronation deposit, about 15 miles east of Deepwater. In this pegmatite vein, the molybdenite present occurred as a segregation of large flakes associated with massive quartz and pink felspar. Usually, however, the pegmatite veins containing molybdenite are too small and podr in molybdenite contents to justify prospecting. (c) Prospecting of pegmatitic, aplitic, or graphic-granite deposits, containing molybdenite. It is concerning this type of deposit of molybdenite, perhaps more than any other, that the prospector needs some advice. The advice, also, is practically of the nature of a warning. The type of molybdenite here considered is very common in eastern New South Wales, and doubtless also throughout Eastern Australasia. In New South Wales, deposits of this nature occur on the Tantawanglo Mountain, in the Bathurst district, the Tamworth district (Moonbi), the Armidale district (Booroolong and Laura Creek), Elsmore, Bald Nob, Tenterfield district, and Wilson’s Downfall. The occurrences are generally large, usually from half an acre to as much as 20 acres in extent. The molybdenite, in these deposits, occurs as small flakes, or nests, in a fine-grained mixture of quartz and felspar, the quartz and felspar being interlocked as a rule, and small holes of irregular shape commonly occur throughout the mass of the rock. Quartz veins and pipes are characteristically absent, but patches of soft mica, greyish or greenish in colour, are common in many exposures. The most characteristic feature of the deposits, however, is the lack of commercial concentration of the small molybdenite flakes. Here and there a deposit is known, as at Booroolong, 52 which has yielded a small patch of ore averaging from 3 to 5 per cent- molybdenite, but the great bulk of the outcrops examined by the Writer would not exceed one-twentieth of 1 per cent, molybdenite. Prospectors- have assured him that within these vast exposures there must be molybdenite sufficient to flood the world’s market, and that all such exposures need is- development “ so as to get below the lean ore at the surface into the rich patches below.” Shafts and holes have been sunk on these outcrops, but they have failed to reveal the existence of any defined “ streak,” channel, or “ pipe,” in which the ore might be concentrated sufficiently to repay mining and treatment costs by such method. In each case, after the most laborious prospecting, the miners appear to be farther from success than when they commenced work. In no case did they possess any clue as to the existence of a rich patch below?' the surface from an examination of the outcrop, inasmuch as the molybdenite flakes were scattered with a kind of regular irregularity throughout the dense granitic rock. In each case they had sunk on the most promising patch of granite in which a few more molybdenite flakes were to be seen to the square fathom than in the areas alongside, but in each case they sank in the dark, as it were, lacking guidance in the nature of quartz vein, “pipe,” or pegmatite vein or pipe. Their only hope was to find a “ pay-patch ” by chance sinking and cross-cutting. In nearly every hole examined by the Writer these holes and shafts show no richer molybdenite concentration than is to be seen near the surface, and,, unless the prospectors should light haphazard upon a rich patch, they have no hope of reward by merely working on. The explanation lies in the fact that granitic patches such as these appear to have been segregated within, or to have intruded, granitic masses during or after consolidation of the latter,, and that the contained molybdenite was part and parcel of these later and more siliceous granites, and separated out as flakes throughout the cooling and consolidating stages, just as the quartz and felspar constituents had done, namely, right throughout the mass generally, in contradistinction to being formed in a vein, pipe, or large segregation. The difference between the quartz, felspar, and molybdenite, constituents of the granite, however, lies in the fact that whereas- the quartz and felspar constitute about 95 per cent, of the mass, the molybdenite forms only from one one-thousandth to- one ten-thousandth of the mass, except in the case of certain areas at Booroolong. In reality the prospectors are quite right in their contention that the- actual amount of molybdenite in these aplitic, pegmatitic, or graphic granite,, masses is immense. Take, for example, the case of exposures such as are to- be found on the Tantawanglo Mountain, near Cathcart in Monaro, or at Laura Creek, in New England, where masses of rock as large as 20 acres in outcrop contain what appears to be about one two-thousandth of their weight as molybdenite. It is highly probable that the molybdenite flakes would be found just as thickly to a depth of 100 yards. Thus in a mass whose exposed portion is 20 acres, and whose depth is 100 yards, and whose molybdenite content is one two -thousandth part by weight, there are about 18,500,000 tons, and of this about 9,250 tons would be molybdenite, truly a wonderful tonnage. Nevertheless, in each ton of granite there is less than 1 lb. of molybdenite recoverable by mill treatment after careful hand-picking, and the value of the molybdenite thus recovered would be less than 4s. , whereas the average mining of such ore to a depth of 400 feet on the pit principle would be 4s., while the hafid-picking of such poor class ore would 53 also exceed 10s. a ton. To this must be added cost of treatment by milling and so on. Thus the winning of this molybdenite r would cost probably ten times its value when recovered. If, however, the prospector is bent upon examining the deposits such as. are here under discussion, then he may like to know that, stated in numbers,, his chance of success is less than 1 in 100. That is to say, he may explore one hundred of these deposits and not find more than one patch of “ pay- ore.” Moreover, such patch of “ pay-ore” would doubtless be small. There are very many of these deposits in New South Wales, but not one has- yielded anything approaching a profit up to the present. Booroolong probably will prove an exception to the rule. (d) A few remarks concerning the occurrence of ore deposits, and true veins in particular, would not here be out of place. The Writer has seen prospectors jubilant at the discovery of mere specks of molybdenite in solid granite, or in small and scattered flakes in tiny joints, containing quartz, or as scattered flakes in hard compact pegmatites of fine texture. Hole after hole is sunk upon these poor and unpromising outcrops with unbounded, faith in the idea that the tiny quartz vein, o,r joint, or the hard hungry granitic rock “ must improve with depth,” or that the scattered flakes in the cavernous granite must give place, at a certain depth, to a magnificent pipe of brittle quartz studded thickly with large crystals and plates of molybdenite. An example of such belief may here be cited. Hearing of an important molybdenite discovery about 2 miles from Tenterfield in a north-westerly direction, an inspection was made of the occurrence. The accompanying figure (Fig. 3) illustrates the nature of the molybdenite de- posit. The molybdenite occurs as bright flakes, of small size, and somewhat like tinfoil or greyish- white scales, in tiny veins of quartz from a quarter of an inch to an inch in width, and of very limited length. These veins were arranged at right angles to the main trend of a tongue of aplitic or pegmatitic granite, which cuts across the “ blue granite ” of the district. The molyb- denite scales possibly formed from 2 to 5 per cent, of the vein material. The molybdenite and the containing quartz in these veins at one time were evidently part and parcel of the granite dyke or tongue when it was in a fluid condition. Upon cooling the granite dyke shrunk in size, much in the same way as iron which has been molten shrinks upon cooling. In this cooling process the consolidated rock cracked at right angles to the walls of the surrounding cooler “ blue granite,” which had been intruded. Into the shrinkage cracks or joints thus produced vapours were expelled from the consolidated but still hot granite. These vapours contained silica, molybdenite, and other minerals. Thus upon cooling the small shrinkage joints took on the form of tiny molybdenite quartz veins. Fig. 3. a = thin veins of quartz, £ inch to 1 inch wide, running at right angles to general trend of dyke. B = “ Blue granite ” of Tenter- field. E = dyke cr tongue (5 to 10 chains wide) of fine-grained sandy granite. 54 In this particular case it is evident that there is no reason to believe that these joints would be any deeper than they were long, nor that they would become wider or richer with much increased depth. Although the idea that molybdenite veins or ore masses generally must get larger and much richer with increased depth is firmly rooted in the minds of the prospectors of New South Wales, nevertheless this idea is against all experience, and the mass of observations by competent workers lies at the base of all mining geology. For example, if a true vein, or lode, is very narrow throughout its course along the surface, and if it is traceable only for a distance of about 100 feet, it is a matter of experience that a lode, such as this, cannot be expected to exist at depths much greater than 100 feet, and, moreover, it cannot be expected to show a greater average width with depth than it shows at or near the surface. If the outcrop of a lode be noted to widen considerably here and there, and if it persists along the surface for several thousands of feet, it is a safe conclusion that a lode such as this may be expected to persist to great depths and that, in places, it will show decided bulges or shrinkages as it is traced downwards. If a group, say, of fifty pipes be examined, it will be found that although each individual pipe may exhibit considerable variations in size as it is traced downwards, nevertheless the average area of all, either at the outcrops or at a distance of a few feet below the outcrops, would be much the same as the average area of all, say at a depth of 50 or 100 feet from the surface. Again, if a large mass of homogeneous aplitic or pegmati tic granite should show an average of one-tenth per cent, of molybdenite at a depth of about 10 or 20 feet below the surface over an area of, say, one acre, then it is safe to conclude that there is very little hope of finding an average content of molybdenite exceeding one-tenth per cent, over any area of an acre which may be exposed parallel to the surface to a depth, say, of 100 feet or greater. And, still further, if the flakes of molybdenite are scattered irregularly over the surface of these huge deposits without evidence of being concentrated in large bunches, in veins, or in pipes, then there is little chance of finding “ pipes,” lodes, or large bunches, of rich ore at any moderate depth. The miner may sink drive and crosscut as much as he pleases, but if the outcrops of these large pegmatitic masses are unpromising and contain only a few flakes scattered irregularly without the presence of “ pipes ” or veins being indicated there, then the prospector would be well advised to abandon such “ large low-grade deposit,” because, large as it may be, it has not a concentration of molybdenite sufficient to justify its exploration. All these estimates of commercial values are based on the assumption of the present price of molybdenite, as also on the present prices of mining and treatment. With regard to molybdenite pipes, no one can tell to what depth they may continue, nor in how many places, nor to \Yhat extent, they may increase or decrease in diameter. All that may be accepted with safety is that they may be expected to bend in a most perplexing manner, and that the molybdenite contents may be expected to occur in patches. Small outcrops of pegmatite in siliceous granites may be either the upper portion of “pipes” or they may be simply “bungs” or masses of irregular shape, which may die away with very little warning. 55 Again, if molybdenite occurs in a spare and scattered manner or in small disconnected patches throughout a mass of quartz, the prospector must expect a deposit such as this to be patchy. If molybdenite occurs in a true vein in patches near the surface, it may be considered that the vein or lode will be patchy. It would occupy more space than can- be given in this report to supply the detailed reason for the beliefs expressed in these paragraphs, nevertheless a very brief reference to certain points in the geological history of the eastern portion of Australia may be of help to the prospector in this connection. The coast of Eastern Australia has not been always in the same position which it now occupies. At various times the sea has extended over the whole of what is now the coastal and plateau areas of Eastern Australia, and on the floor of this sea, which was more or less shallow, flat beds of mud, sand, and pebbles, have been deposited. At various times, on the other hand, the dry land has extended to the east of the present coast of Eastern Australia. More than once the flat beds of mud, sandstone, and pebbles, laid down thus on the sea floor have been squeezed or shoved strongly from the side, and have thus been folded into high mountains, and upon these the weather, the streams, and the waves, have played so long that their original form has gone long since. The waste derived from this action of weather, streams, and waves has gone to provide additional layers or beds of mud, sandstone, and pudding-stone to be deposited on the neighbouring sea bottom. It does not concern us here as to how these flat beds were squeezed and folded so as to produce great mountain ranges at various times where previously there had been only the sea with its silt and sand; but it is of interest to us to know that, during their formation; very large reservoirs of molten rock were tapped at a considerable depth below the earth's surface in these crumpled regions, and that from these hearths or reservoirs great masses of molten rock were forced upwards into the cores, or axes, of the folded sediments. Molten rocks such as these included serpentines, diorites, and granites both of dark and light colour. These rocks, which all resemble granites, do not appear to have reached the surface and flowed out as lavas do, but they appear to have consolidated and cooled beneath a cap of slate, sandstone, quartzite, porphyry, lava, or volcanic ash. Thus a prospector walking over the surface of New England at such a period might have been walking over granites with molybdenite pipes, yet he would have had to sink through thousands of feet of slate or other rock to find them. As these granites, diorites, serpentines, and related rock types, crystallised and consolidated from the molten stage, they became smaller in volume, and in doing so they developed a wdiole series of zones of weakness, which appear in part to have formed joints subsequently. Along these zones of weakness, as well as along others, a gaseous or watery residue from the cooling magma worked its way towards the cooler surrounding rocks, such as slates and porphyries, which had been intruded by the granite. In the siliceous or sandy granites these vapours or waters contained much silica, while in many cases they also contained molybdenite, bismuth, wolfram, tin, with lesser quantities of gold, silver, copper and iron. These vapours and waters gradually filled certain of the weak zones of the shrinking granite with quartz, pegmatite, and aplite, and with these also were deposited much molybdenite, bismuth, and other minerals. Many “ pipes ” also were formed by the action of the mineralised vapours w-orking along intersecting joints near the margin of the sandy granites. 56 In Victoria and southern New South Wales, however, the molybdenite deposits are older than those which are found north of the Hunter River in New South Wales. The mountains which we have mentioned here were worn away gradually by the weather and the streams, and plains were carved out of them near the sea level. Thus the granites, which had been hidden under a load of slate and other rocks, were exposed in the fulness of time to the light of day The low-lying plains were lifted in turn, slowly but surely, and in this way the present plateaus of Eastern Australia were formed. While both the earlier mountains and the later plateaus were being denuded, the molybdenite deposits in the granite were uncovered. As the granites w r ere worn away so also were the molybdenite deposits which were contained therein. The associated deposits of tin, bismuth, gold, and w r olfram, were also worn aw r ay at the same time. The tin and gold contents, being less perishable than the Plate VII. Stereogram illustrating occurrence of pipes in the marginal portion of a granite mass. The four horizontal plates are supposed to represent plateau surfaces at various periods, thus showing how any plateau surface cuts pipes or other ore deposits at varying depths below their topmost portions. molybdenite, wolfram, and bismuth, v r ere carried into the neighbouring watercourses, and there formed rich shallow leads. On the other hand, the molybdenite, bismuth and wolfram, were more perishable. The bismuth and molybdenite were changed into a yellow dust, and the wolfram was changed into iron-oxide in great measure. At a later date, again., these stream deposits were buried either under floods of black lava or under thick masses of sand and clay. These formed the famous Deep Leads. Now, in this gradual exposure of the molybdenite deposits by the action of the weather and streams after elevation of the land, it is evident that all of them were not affected equally. On the other hand some were worn away entirely, others were removed in part, while others were exposed only as to their upper portions. This is evident because the molybdenite, as also 57 the associated deposits, were arranged near the roofs and the walls of the high granite masses, and, as may be seen by a glance at the accompanying figure, any chance plain or plane (AB) cut through the mass, such as a plateau surface, would pass naturally through various deposits at variable heights from their uppermost portions. The prospector thus who examines any large group of molybdenite deposits such as those at Rocky River, Deepwater, Kingsgate, Bega, or Whip stick, may rest assured that the numerous pipes or veins composing these groups have been worn down in variable degree. The tops alone of some have been worn away, while the outcrops of others are hundreds of feet below their original tops. Others again, not visible to-day to the prospector, have been worn away entirely ; while others have their uppermost portions buried deeply below the surface, and it is doubtful whether any trace of them would be visible at the higher level. On the other hand, were the upper 2,000 feet of the present plateau and coastal masses to have been removed, it is highly probable that the molybdenite veins and pipes worked at present would have been worn away entirely. Nevertheless, it is probable that many other pipes and veins would have been found both on the upper surfaces now removed and on the deeper surface not yet exposed. From this the prospector may understand that the more superficial portions of the molybdenite lodes, “ pipes,” “ blows,” and “ bungs,” exposed to-day may be taken as a fair average sample of what he may expect to find upon sinking, allowance being made for the oxidation of the molybdenite to depths varying from 5 to 30 feet from the surface. The main lesson to be learned from this brief note is that lodes, pipes pegmatitic, and aplitic, deposits containing molybdenite cannot be expected to become either richer or larger, on the average, at considerable depths than they are at shallow depths below the present surface. 58 XL— DESCRIPTION OF LOCALITIES AND INDIVIDUAL DEPOSITS OF MOLYBDENITE IN NEW SOUTH WALES. Abington or Abingdon. See Laura Creek. Adams’ Claim. See Boundary Creek, under Rocky River. Adams’ Claim. See Tantawanglo. Allies Mine. See Deepwater. Amosfield. See Hughes’ Wolfram Lode. Angoperran. See Bolivia. Appleby’s Claim. See Bolivia. Ardlethan. Ardlethan Deposits. Molybdenite occurs in the Ardlethan district in granitic rocks as an accom- paniment of tin. Its occurrence, however, in the subject area appears to he merely a mineralogical curiosity. Mr. J. R. Godfrey,* Inspector of Mines, records the mineral from Buchanan’s Mine (p. 24), The Ranchero Syndicate (p. 60). Mr. Godfrey notes on p. 6, that “ The tin oxide is frequently associated with bismuthinite and bismuth ochre, molybdenite, wolfram, chalcopyrite, mispickel, cerussite, pyromor- phite and zinc-blende.” Mr. Geo. James, Mining Warden at Cootamundra, in a personal com- munication under date 25th January, 1916, states that the occurrence of molybdenite at Ardlethan “ has been observed on P.M.L. 110, Parish Warri, Persse and Baker, lessees, and on the adjoining lease, ‘ The Outcast,’ F. W. Watson, lessee. . . . There have also been traces observed at Merry- bindinyala, 7 miles from Bethungra, in the form of scales in the stone.” Arsenic Blow. See Kingsgate. Attunga Creek. See Moonbi. Backwater. See Oban. Baker’s (E. A.) Claim. See Deepwater. Baker’s Hill. See Glen Eden. Balderslie Deposits. See Booroolong. Bald Nob. Bald Nob Deposits. 1. Mur fhy and Young's Lease. — P.M.L. 8, nearly 4 acres on Portions 35, 52, and 64, Parish Bloxsome, County Gough. Near the main road from Glen Innes to Grafton, and about 15 miles east of the former town. Molybdenite occurs in the lease within pegmatitic granite and quartz, -at or alongside an intrusive junction of finely -textured and very sandy granite with a quartz-felspar porphyry. The intrusive contact is very irregular (Fig. 4 [a]), and a considerable amount of greisen has been developed along the general contact in the vicinity of the lease. The granite would be classed as a tin, rather than a molybdenite, type. The outcrop containing the molybdenite is large, and is composed of a cavernous aplite or pegmatitic * The Ardlethan Tin-field. Mineral Resources No. 20, Dept. Mines, N. S. Wales, 1915, pp. 24, 60. UBRAKV 0 f i HE UNivthsinr of Illinois 59 granite, the mineral sought being scattered about in flakes as an original constituent of the pegmatite. There is no surface indication of any con- centration of the molybdenite into veins, pipes, or bungs. A shaft (Fig. 4 [ a \ ) has been sunk to a depth of 28 feet in the drusy and sandy granite outcrop, and a hole about 6 feet in depth has been sunk in a similar granitic rock a little to the north of the shaft. These workings have pros- pected, in some measure, an outcrop of rock about 50 feet in length and about 15 feet in width, and throughout all of which molybdenite flakes are scattered. As with all similar occurrences, such as at Booroolong, Moonbi, Laura Creek, Tantawanglo, and Tarana, the great difficulty encountered here by pros- pectors is the lack of relative concentration within some body, which could be followed with some measure of certainty, such as a vein or pipe. The deposit might be prospected by sinking vertically for, say, 50 feet, and crosscutting for 25 feet in each direction from the base of the shaft. Should no vein, pipe, or “ bung,” be revealed by such work, or should the average molybdenite content of the stone as mined in sinking the shaft and in crosscutting not exceed 4 per cent., then the deposit might be considered as valueless under the present conditions. It may be pointed out here that there is very little hope of finding veins, pipes, or large rich pockets, of molyb- denite in these aplitic and pegmatitic phases of the sandy granite, inasmuch as they form a type to them- selves, just as pipes and veins are types. The form under con- Fig. 4 (a). Young’s Lease. Parish of Bloxsome, County of Gough. Young’s Lease. Parish of Bloxsome, County of Gough. sideration is one which is generally large to very large, without definite shape, and one in which the molybdenite is scattered throughout the mass as a very subordinate constituent compared with the quartz and the felspar present. 2. Young and Murphy's Claim. — M.L. 18, 1 acre on road between Portions 34, 64, and 72, Parish Bloxsome, County Gough, about 500 yards from "Murphy and Young’s Lease (Fig. 4 [a]) 60 Encouraging prospects of molybdenite were found on this lease in sandy granite near its intrusive contact with quartz-felspar porphyry. A consider- able development of greisen occurs along the contact. The deposit is sug- gestive somewhat of a pipe at the surface, but very little work has been done to prove its nature. The ore occurred abundantly in the outcrop, both as yellow molybdic ochre and as flakes of moderate size in a matrix of quartz with felspar crystals. Ballandean. See Tenterfield. Bathubst. Molybdenite flakes in granite and quartz have been recorded from various parts of this large district, to which, indeed, Yetholme (which see) itself belongs. The accompanying list of localities is a record mainly of occurrences of scientific interest only. The information has been supplied by Mr. Warden P>urke. 1 . Portions 74 and 107, Parish Thornshope, County Roxburgh. 2. Portions 144 and 155, Parish Bolton, County Westmoreland. 3. Portions 87 and 95, Parish Melrose, County Roxburgh. Bega Deposits. The Black Range Deposits. These include the Queensgate, or Jackson’s Reef, Finucane’s Reef, Joseph’s Reef, Scott’s Reef, Gleeson’s Claim, and Portion 220, all in Parish Kameruka, County Auckland. These deposits all occur in the Black Range, about 6 or 7 miles to The south of Bega, but, owing to the roughness of the country, the. deposits are best approached by a circuitous road about 10 miles in length. The undulating country around Bega consists of basic granitic rock types, which are relatively weak when exposed to stream and weather action, and the hills around Bega consist, for the main part, of dense Devonian conglomerate, •sandstone, and silicified claystone. The higher portions of the Black Range are composed, in the main, of Devonian sediments, while the gully bases and sides, in the range, commonly reveal the existence there of granite. In the range itself basic granite of the Bega type occurs, but the prevailing type is very siliceous in nature, generally fine in texture, and suggestive of a marginal intrusion into the older Bega type. At the Queensgate mine the reef occurs in the basic granite, but the reefs or lodes within the adjoining leases occur in siliceous granite. The molybdenite deposits of the Black Range are somewhat peculiar in That they occur as true lodes of considerable width, composed of compact white to translucent quartz. The granites are post-Devonian and pre-Permo-Carboniferous in age. 1. Jackson’s Lode, or the Queensgate Mine. — This comprises M.L. 3, of 40 acres, Parish Kameruka, County Auckland. The position of the lease, its topography, and the main geological features are indicated on the accompanying sketch map (PL VIII). The country is rugged and covered with brush growth. The western portion rises about 700 feet above the creek draining the lease, and is composed mainly of dense Devonian sediments. The granite containing the lode at the eastern portion of the lease is basic in nature and has intruded the sediments in a very irregular manner, forming numerous sills. 61 The molybdenite is contained within a true lode, which has a strike almost east and west, and a uniform and high dip to the north. The vein or lode has been traced for a distance of 175 to 200 yards along the surface, and it has a width varying from 15 to 40 inches. The vein is of quartz, dense Plate VIII (a). A — Devonian conglomerate, grit and sandstone. B — Sediments with granite intrusions. C — Granite, basic in the eastern, and siliceous in the western Mineral Leases. Plate VIII (6). O 10 20 O 500 tOOO HORI/ONTAl SC Air I I i CHAINS . VIRTUAL SCALE i i i EUT and white, with very little indication of holes or vughs. Both footwall and hanging wall are well developed. A powerful set of horizontal joints occurs in the vein at distances of a few feet apart. Throughout the quartz molybdenite occurs in a very fine state of division. The uppermost portions of the lode showed very little molybdenite, as proved by shallow prospecting holes, but a shaft, aided by the Prospecting Vote to a depth of 100 feet (P.B. Mines 15/5035), has been sunk to a depth 62 exceeding 50 feet from the surface, and molybdenite may be seen as though painted throughout the joints of the stone. The lode averages about Id inches in width in the shaft. A heap of stone about 40 or 50 tons in weight had been stacked round the shaft during my visit in March, 1916. The average molybdenite content of this patch of stone exposed in the shaft has not been ascertained, but a plant has been erected at a cost of about £1,300 to treat any ore which may be found in the future. This treatment plant has been described elsewhere (pp. 12, 13) in this report. Since visiting this mine I am informed that a drive has been put in 100 feet in length, and that 75 tons. of ore have been won altogether. The ore won appeared to me to contain from T5 to 2 per cent, molybdenite ; and a sampling of the ore exposed in the drive yiejded a return of 2’3 per cent, molybdenite approximately. 2. Gleeson's Claim. — This is included in M.L. 4, Parish Kameruka, County Auckland, and lies immediately east of M.L. 3, or the Queensgate. The lode prospected by Gleeson and Party is an eastern continuation of the Queensgate lode. A shaft had been sunk about 60 feet in depth on a lode averaging more than a foot in width. Molybdenite in fine flakes occurs throughout the stone. The lode at Gleeson’s shaft is near the intrusive granite contact, but the cover of altered Devonian sediments appears to be very thin, and the lode may be continuous in the granite below this cover. 3. Finucane and Edwards' Claim. — This occurs within M.L. 1, a rugged area adjoining M.L. 3 to the north. In this lease the granite is very siliceous in nature, and is capped by Devonian claystone, sandstone, and cliffs of conglomerate, all gently bedded at this point. Finucane’ s Reef is a dense mass of quartz of white colour, having a general east and west strike and a uniform and high dip to the north (see Map). The lode traverses very rugged country, and has been tested by a couple of shafts and several prospecting holes. The more western shaft was sunk some years since and is about 60 feet deep, according to report, the lode exposed being from three to 4 feet in width. A shaft about 20 feet deep, and about 40 yards to the east, had been sunk on the lode, here about 30 inches wide and formed of massive quartz. Fine molybdenite occurs throughout the lode as in the Queensgate lode. A parcel of several tons was picked from the crude ore during March, 1916, and was to have been treated at the Queensgate plant. It is impossible to state what percentage of molybdenite might be expected to be won from this stone from a mere inspection of the stone. 4. Joseph's Reef occurs in the western portion of the lease, and is indicated on the accompanying sketch map as a powerful quartz lode, which has not been proved to contain any deposit of commercial value as yet. 5. Scott’s Reef. — This occurs in M.L. 2, Parish Kameruka, County Auck- land, adjoining M.L. 1 on the north. The lode crosses the ridge through the siliceous granite. It is composed of dense bluish-white quartz, with a strike almost east and west, a high dip toward the north, and a width varying from 4 to 6 feet. Traces of molybdenite and bismuth are reported from the Underlie, or Scott’s Shaft, which is said to have been sunk on the lode many years ago to a depth of 40 feet. A softer crushed formation on the footwall side of the main lode is reported to have yielded gold and silver. 6. Portion 220. — This also lies on the Black Range, the granite out- cropping at the base of a steep hillside capped by Devonian sediments. The granite contains molybdenite in joints near its contact with the sediments, but the prospecting work has not revealed the existence of any molybdenite deposit of commercial importance. Plate VIII A [Photo by J. W. Fawcett .] (a) Concentrating Plant at Queensgate Mine, Black Range. Plate VIII A [ Photo by J. IK. Fawcett.] (b) Jackson’s Shaft, Queensgate Mine. 63 Bethungra Deposits. Betts’ Claims. See Moonbi. Binghi. See Mole Tableland. Black Shaft. See Yates’ Pipes under Kingsgate. Black Range Deposits. See Bega. Bluff. See Tenterfield. Bluff Land. See Tenterfield. The Bolivia Deposits. The general disposition of the Bolivia deposits is shown on the accompanying map of the Bolivia district. The molybdenite is found in association with two types of granite, and these two types are recognised easily by their topographical, geological, and other features. The large granite exposure, occupying the central and western portion of the area indicated on the map, is a striking topographical feature viewed from Deepwater or Bolivia. It forms a dissected plateau with rugged slopes rising above the general level of New England at Deepwater. The Great Northern Railway traverses it by means of a long wind-gap, and descends thence to Bolivia along a steep and dangerous cutting, known as the Horseshoe bend in its lower portion. This granite is a coarse granular type, very sandy in nature, and covered with stunted and scrubby vegetation. It is the eastern extension of the Great Mole Tableland granite, which has yielded so much tin and wolfram. The molybdenite occurs all round this mass in scattered flakes, and in numerous portions in Parish Bolivia, to the immediate north of the Angoperran granite. The latter occurrences, however, are associated intimately with small outliers and dykes of aplite, pegmatite, bosses, and graphic-granite dykes belonging to the main Angoperran mass. The Booroo or Splitter’s Swamp granite is indicated on the map as the eastern portion of the area mapped. Whereas the Angoperran granite and the associated quartz-felspar-porphyry form striking topographic features, the Booroo granite appears to be sunken well below the surrounding plateaus and to form the base and sides of a wide valley. This type is not nearly so siliceous as the Angoperran type, and its vegetation is not of a type so stunted as that which the western granite supports. Molybdenite occurs along its margin in pipes of a highly encouraging appearance, whereas the wolfram granite of Angoperran carries deposits of molybdenite which are not nearly so promising in appearance. In 1915 the Writer inspected isolated deposits of molybdenite both at Booroo, Bolivia, and Angoperran, and was at a loss to understand how one and the same type of sandy granite could present appearances and ore deposits so variable as those of Booroo and Angoperran. The intermediate country was very rugged and steep, and the prospectors did not appear to have considered the question of the possibility of the two granites being distinct. With this problem in mind a trip was made one day with Mr. A. E. Cooper, and another with Mr. Collins, of Deepwater, with the idea oi determining the granite boundaries. It was then ascertained that a high and rugged bar of quartz -porphyry separated the two granite types; that the lava type had been intruded by both granites, but that they had never invaded each other’s area, although in one place they were less than one 64 mile apart. It was then evident that the Booroo granite was not merely a phase or segregation of the wolfram type, hut that the two granites were of different types. The Booroo granite is closely allied to the Bow Creek and Kingsgate types in general appearance, in silica percentage, in topography, and in the vegetation which covers them. Moreover, they are strikingly alike in the manner of occurrence of the 'molybdenite pipes, although the Kingsgate types are more in the nature of true quartz deposits, whereas the Booroo and Bow Creek types are more granitic in character. This type of granite may be called the true or normal molybdenite granite. Owing to the greater resistance of the quartz-porphyry to the agencies of denudation than the Booroo granite, the former stands above the latter in high escarpments, which are rugged in places, as at Cooper’s Claim, in Portion 44. Inasmuch as the important pipes which hug the margin of the granite in Booroo occupy thus the area below the escarpments, there is a decided tendency for their outcrops to be concealed beneath the debris- showered upon them by the steep porphyry hillsides. Prospecting for pipes is thus a difficult matter, and only skilled and persevering prospectors can hope for success. It may be noted that four or five pipes are shown along the junction of the Booroo granite with the quartz-porphyry, but there is no reason to believe that many more pipes do not exist along the granite margin in the long line of contact indicated in the map as stretching from Mount Capoompeta (The Magistrate) on the Main Divide to a point one mile north of Bolivia railway station. 1. Appleby’s Claim . — About 60 yards in a direction south-south-west from the north-west corner of Portion 115, Parish Angoperran, County Gough, and about 13 miles north of Deepwater. Molybdenite and wolfram occur here in a pipe composed of a quartz paste or base containing felspar grains and crystals, all within a coarse sandy granite of the wolfram type {see Map). The deposit occurs about 150 yards from the intrusive junction of the granite with quartz-porphyry. A pink granite of fine texture (tin granite) appears to have a local development in Portion 115, between the main mass of the coarse granite and the quartz porphyry. The granite containing Appleby’s deposit is a continuation to the east of the Great Mole Tableland granite, which extends continuously from a point near the Dumaresq Biver on the Queensland border, through Torrington to the site under consideration. The map is a continuation of the one illus- trating the Vegetable Creek tin-field by Professor T. W. E. David,* and extended eastward by Mr. J. E. Carne.f Appleby’s deposit has not been prospected beyond a shallow depth. Its outcrop appeared to be about 6 feet across, and the molybdenite and wolfram ore was followed to a depth of 30 feet measured along the underlie, but only 15 feet in a vertical direction. It is stated that the deposit was prospected twenty -two years ago by Mr. Cassidy, of Deepwater, for wolfram, and only reworked at a later date by Mr. Appleby. The molybdenite occurs in crystals and flakes of considerable size associated with small and scattered lumps of wolfram. This claim has been abandoned temporarily owing to the lean nature of the stone prospected to date. * The Vegetable Creek District. Memoir No 1, Dept. Mines, New South Wales. 1887. t The Tin Mining Industry. Mineral Resources, No. 14. 1911. See map of Emmaville District. The eastern limits of Professor David’s and Mr. Carne’s areas are approximately the western limits- shown on the map accompanying the present report. Received from the Minister for Mines the undermentioned publication of the Geological Survey Branch of the Depart- ment of Mines, Sydney : — 04 6 CO LLl O C£ => o co LU q: ro <3J Q a> o (30 2 2 • • e8 <3 -h .O .2 _ _ ’-3 ’-3 S3 S3 t-i s-, Z Z t> t> a*-, O O ' T3 «5 . > ai C© : c© cog CO — I x x 0 o *4 I— a, s© . . . 5 * l! : : : 43 43 -*3 43 1 iiio — i wm -uo s o ©>£ rJ1 £ «- o H « 0) O 43 w.S **4 (-1 _o o S ©1 ;o ■5 5? O C S3 51^3 | 9. 3, 2 § G .3 % D n 02 S ° o 6 "2 O J CO *8 g S3 J-3 c E 88 CO^;" O | ^3 -d • • S3 -h -S i § S3 © S3 O X 05 rt X* d3 © ©3 Hoi ^Xi ® ^ t: /ffl o O Oh o mh hhPH o sh o 2 2 2 « S 2 o c o o 3 ^ S3 «*h 2 Z ° s tH 2 ^ ^ C) H 1 * 1 ° £ £ o «+H w "gx"© HN © h|n CO t— XO fc & a 2 o «« t-l MH 02 “x o © 2 S3 • 5j ^ S3 ce o . © ©02 qH | ^02 2 05 05 ^ l^od «s g © CO SO S 02 02 02 00 02 02 £ £ £ £ o o o o (-1 t-l t4 t-l ■4- H-l 4-( =+H 02 OQ 02 02 3 3 3 3 x x o o © o o c -H 51 © 00 ^ 3 Sood oo O Ol (M ^ © O S3 t, €. "1 § © h 1 H S ©ICO ^ © o Soq02 © - © j ^ © e © ©3^;« c 8^ 8 © S3 £- C C5 n-t O OO ©3 — (20 ©3 g ©3 c3 ©3 ©3 00 05 O -+ ©3 Tf< 4* O ft CO T* »C cot- GO 05 0 i— i 03 CO ■ 00 05 O — i ©3 CO — i — i ©3 ©3 ©3 ©» Prospected on surface only t Worked along footwall only. J Three additional pipes hare been found in the southern portion of Block 24 during 1916. Schedule of Pipes, Kingsgate — continued. 102 So «*-( T 3 o c a> V «o o —I >& ft fff o Soco O U 5 H cq © (D g (D m 5*8 £ _o W ft £ e 3 ► CO O M o PQ £ O Hm 1—1 w r»< 1 I 1 1 Jill TJ ft •S S’S - 5 ® ^ "* h 2 ° **• 1 g § 4 1 ■S§ 4 «J O +3 l© l© I© tO ^ O w ~ ft H- 0 HH O P O u 1 s s o o ft ft s§* •sg al ^ ® © g ip. +>£ ft * „ a >© 43 09 e H* © O 05 * *• § (2 8 ^ s 8 * . _o : ft 1-5 •OKM S gslsa^ & CO ..ftft 0«IH« ^ >% J ^3 **| 83 31 J a co O -» g o o to (M O _ _ . ft*«H Ml GO ^ ^ cd cd ® S 4h ci A A >^rO D o o © ^ <; — Op, ■ **<«<* 129 The locality was examined in March, 1915, by Mr. J. E. Carne, Government Geologist, who has supplied the accompanying notes, together with other notes on individual claims, fo? this report : — “ The molybdenite veins occur about miles southerly by road from Macksville on the Nambucca River, and within lj to 2 miles of the North Coast Railway under construction in the northern extension of the Mount Yarrahappini granite, close to its junction with sedimentary rocks.” The accompanying notes on some specimens of country rock from the Warrell Creek deposits have been made by Mr. G. W. Card, Curator of the Mining Museum. The specimens were collected by Mr. J. E. Carne. Rock specimen 9075. — Granite, light grey in colour, of fine and even texture. It is speckled with biotite, and is not markedly quartzose. Iron pyrites is present. No. 9076. — A granite similar in appearance and composition to No. 9075. It is a little coarser than 9075, and contains but very little biotite. Microscopic Characters. No. 9075. — Much fresh felspar is present, a considerable proportion of which is plagioclase, showing well-marked zoning. Biotite is only subordinate in amount, and shows pleochroic haloes, with zircon. An isolated grain of hornblende was noticed. No. 9076. — Much of the felspar present is micro -pert hi tic, and a fair pro- portion of the felspar also is oligoclase. The felspar is somewhat clouded, and alteration to sericite has commenced. Certain crystals show a cltar outer zone. Quartz is under slight optical strain. Biotite is very scarce, and shows more or less bleaching, with some development of sagenite webs. Pleochroic haloes are visible around the zircons. 1. Kritsch’s (L. B.) Claim. — Notes by Mr. J. E. Carne : — “ The claim of this name occurs within M.L. 16 of. 20 acres. This was the prospecting claim mentioned in 1904. The shaft in 1915 was full of water and consequently not open to inspection, labour conditions having been suspended in March of that year. “ In this lease a series of quartz veins occur, short in length and erratic in distribution, making here and there, at intervals, along a direction varying from N. 80 degrees E. to east and west approximately. As many as three parallel veins may be traced fora few chains in length along the rough channel of the creek. “ Much of the quartz filling is of barren nature, although occasional vughs occur containing molybdenite. The molybdenite content of these veins is 1 patchy,’ in places, the flakes of the mineral sought are fairly abundant, whereas the intervening areas have a much lower content of molybdenite. “ It is possible that a moderate amount of concentrate might be obtained from the stone lying about the shaft mouth. This would require crushing and screening. “ From this base about 5 cwt. of rich molybdenite concentrate is reported to have been won in 1904.” 2. McLeods' ( J . and S.) Claim. — Notes by Mr. Carne : — “ J. and S. McLeod’s molybdenite claim adjoins that of Sutherland and party (M.L. 3) upstream along Woy Woy Creek, in M.L. 2. t 68791— E 130 “ In this lease some narrow veins of quartz with molybdenite out- crop both in the bed and banks of the creek. In width they vary from mere threads to a maximum of 2£ inches, and their general strike is about north 10 degrees east. These veins, or joint planes, pinch out horizontally within a few feet in places, and they are more or less parallel to each other, although arranged en echelon in plan. “ The relatively great width of the barren granite separating the veins, as compared with the widths of the veins themselves, together with the insignificant lengths of the individual veins renders open- excavation methods of mining, such as is the case with some stock- works, impracticable owing to the amount of dead work involved, to say nothing of the extreme hardness of the country rock. Each small vein thus necessitates mining by itself, excepting in such cases where two or three veins may lie within a zone whose width does not exceed that necessitated by ordinary mining operations. “ A shaft was sunk to a depth of 26 feet on an eastern vein which had a width of 1 to 2^ inches, but which did not persist in a horizontal direction. At a depth of 26 feet in the shaft the molybdenite was fairly solid, and, at a lower level, the molybdenite, in places, occupied the whole width of the vein. At these places, as also in the spots where the quartz occupies the greater portion of the veins, the molybdenite occurs as crystals in stellate groups. “ In the granite alongside, parallel veins about one-sixteenth of an , inch in width occur in a bank of the creek. “ In these veins the molybdenite is associated with a small percentage of pyrites and chalcopyrite in quartz.” Magnificent specimens of rosettes and crystal clusters of molybdenite in quartz are on exhibit at the Mining Museum through the kindness of Messrs. Hollibone and Parnell. An illustration of this ore is to be seen in PI. XIX. Fig. 20 also illustrates the association of quartz, molybdenite and country. It is not known whether the specimens shown on PI. XIX were secured from McLeod’s Claim or an adjoining one. During 1915 it is stated that about 24 tons of ore were raised, estimated to yield about 1 ton molybdenite. 3. Myra-Lucy Deposit . — Notes by Mr. J. Carthew, Inspector of Mines. The deposit is distant about 3 miles in an easterly direction from Warrell Creek, near Butcher’s Creek, Parish Warrell, County Kaleigli. It was held under Miner’s Right on Crown land in 1914. The occurrence was a quartz reef containing molybdenite. The strike of the vein was east and west approximately with a very flat dip to the north. In July, 1914, Mr. Carthew reported (P.B. Papers. 14-3061 Mines), that the work done consisted of trenching and sinking a shaft 6 feet in depth. It was proposed to sink a shaft to a depth of 50 feet “ The ore veins are showing in very hard quartz on both sides of the creek. Unlike the deposits at Kingsgate, the mineral is disseminated through the stone. . . .” 4. Parker's ( W . H.) Claim . — Notes compiled from information supplied from Mr. Parker and from specimens brought in to the Department of Mines at various times by Mr. Parker. The deposit or deposits are said to occur on the east side of Mount Yarra happini, about 6 miles from Stewart’s Point by falling road, and about 3 miles east of McLeod’s mine. The specimens shown consisted of large and thick flakes of molybdenite apparently scattered irregularly throughout a 131 very sandy granite containing small quartz veins. The numerous specimens seen suggest that the molybdenite has been deposited in part in small joints and veins, and that the vapours containing the molybdenite also deposited the mineral, in part, within the granite alongside or near the tiny veins. From an inspection of the specimens this locality appears worthy of being prospected. 5. Sutherland and Party's Claim. — Notes by Mr Carne : — “ The deposit nearest to Macksville is that worked by Sutherland and Party on M.L. 3 in the bed and banks of Wo y Woy Creek, not far above its junction with Warrell Creek. “ The molybdenite occurs in thin and non- persistent veins or joints in siliceous granite. It is associated with quartz, pyrites, chalco- pyrite, galena, and mispickel. The principal vein in this claim has a strike of north 10 degrees west, and, so far as had been proved up to the time of my examination, it had a width of about a quarter of an inch. Other exceed ingly narrow veins, or joint planes, occur within an apparent width of 20 feet approximately. “ The molybdenite assemblages, where most pronounced, occur as beautiful crystals having a stellate arrangement. “ Surface prospecting only was in progress in March, 1915.” The following notes have been supplied by Messrs. J. H. Trevarthan and G. S. Ashley. “ H. McLeod’s Prospecting Area is on the western slope of Woy Woy Creek, and molybdenite has been found in several places, but a zone of granite with quartz can be traced within the subject area, carrying a fair percentage of molybdenite within a width of 2 or 3 feet. The prospecting holes seen did not exceed 3 feet in depth.” “ Ainsworth’s Property occurs on the eastern slope, about two miles from H. McLeod’s. Molybdenite occurs in the quartz veins and granite.” “ North of Macksville, about 10 miles, on the western slopes of Mount England, molybdenite occurs in several places. One or two areas have been taken up, and some prospecting work done therein. On a quartz vein about 2 feet wide, a prospecting hole has been sunk to a depth of 7 feet, and molybdenite can be seen both in the quartz and the surrounding granite.” Monkey Shaft. See Kingsgate. Mount Metallic. See Whipstick. Mount Morgan. See Kingsgate. Mount Tennyson. See Yetholme. Murphy’s (Wm.) Claim. See Bolivia. Murphy and Wilson’s Claim. See Bald Nob. Murphy and Wilson’s Claim. See Kingsgate. Murphy and Young’s Clatm. See Bald Nob. Fig. 20. Sketch section of quartz vein with molybdpnite at Warrell Creek in one of the rich portions of the veins. 132 Myra-Lucy Claim. See Nambucca. Newsome’s Block. See Glen Eden. Nymagee. Molybdenite specks and flakes in a tight quartz in sandy granite. Speci- mens secured by Mr. D. Jones, a prospector. Oban. 1. j Lowe’s Claim. — M.L. 73, of 10 acres, at Lode Hill, or Backwater, Parish Coventry, County Clarke, about 30 miles south- south-east of Glen Innes. The claim under consideration occurs on a plateau about 4,200 feet above sea level, at a point near which the upland falls away suddenly to the Mitchell River, many hundreds of feet below. Molybdenite occurs within the lease with wolfram in very small quartz veins, and these are grouped in a narrow zone within a very sandy granite near its intrusive contact with a dark hornblendic granite. The granite MITCHELL OR SARA Fig. 21. Sketch geological map of Lode Hill, in Parishes Towagal and Coventry, County Clarke. containing the molybdenite veins is the typical tin granite, consisting of an intimate mixture of quartz and felspar, fine in texture, and of a pinkish- grey colour. Here, as in other parts of eastern New South Wales, the tin- granite presents striking contrasts with the associated basic granite. It forms a striking topographic feature, rising abruptly and in rugged manner from the gentle swellings or plain-like appearance of the basic type. More- over, it is covered with dense scrubby growths of tea-tree ( Leptospermum ), wild daphne ( Brachylome ), whitebeards ( Leucopogon ), geebungs ( Persoonia ), purple pea ( Hovea longifolia), honeysuckle (Banksia), oak trees (Casuarina ) , 133 native cherries ( Exocarpus ), bottlebrushes ( Callistemon ), wattles (Acacia), and other types, which make surveying a difficult matter. On the other hand, the hornblendic granite, where extensive, may be recognised at a glance by the park-like nature of the country, by the presence of isolated and picturesque tors or clumps of large rounded rocks dotting the plain, by the clumps of open forest composed of New England peppermints (Eucalyptus nova anglica), white sally (E. coriacea), black sally (E. stellulata), white gum (E. viminalis and E. rubida), and by the large open spaces between the forest clumps, covered thickly with grass and frequented by carolling magpies. The junction of the two types is separated almost as cleanly as with a knife by the plants and the topography, the undulations of the open parkland ending abruptly against the rugged and rocky topography, clad with dense stunted forest and scrubby undergrowth. The accompanying sketch map (Fig. 21) indicates the approximate junction of the two types between Portion 73 and Mount Mitchell. The molybdenite veins have a strike approximately N. 35 degrees E., with a dip almost vertical. The strike of the veins is almost at right angles to the general direction of the hornblendic granite and tin granite contact (Fig. 21). The main vein has been traced for a distance of 60 or 70 yards from the intrusive contact. It is from 4 to 10 inches wide, and it appears to contain very little molybdenite. Almost alongside the granite contact, however, there are several very narrow veins, varying from J to 1 inch wide, and these appeared to contain a fair percentage of stout molybdenite flakes. These veins, however, are too small for profitable mining, except by a couple of prospectors, who might mine and concentrate the ore with very simple machinery. Oberon Deposits. 1. Duchmaloi River. — Held under Authority to Enter, of 20 acres, on Portion 133, on private land owned by Johanna Boyle, Parish Norway, County Westmoreland, about 9 miles north-east of Oberon. The deposit under consideration is known as Dwyer’s (D.) Claim. Mr. David Milne, Inspector of Mines, reported as follows in 1915 (P.B. Papers, 15/3717 Mines). “ The occurrence consists of granite and garnet rock, containing minute specks of molybdenite and bismuth sulphide. A shaft was sunk on the lode formation some years ago by Messrs. Baker Bros, to a depth of 40 feet, or thereabouts, in the formation. Occasionally a speck of molybdenite can be seen. A crosscut tunnel had been put in also about 40 feet long The prospects obtained in the old shaft, and the appearance of the lode formation were poor.” 2. Lowther — Webb and Party's Claim (also known as Ryan’s (M. J.) Claim). — The accompanying notes have been supplied by Mr. E. W. Finch, of Sydney. P.M.L. of 10 acres, on M. J. Ryan's private land. Portion 35, of 83 acres, Parish Lowther, County Westmoreland, about 18 miles from Mount Victoria and 4 miles off main Jenolan Road from Mount Victoria. The deposit is situated on a steep spur of red granite, and it occurs as a series of small quartz veins, one having an average width of 8 inches and underlying about 50 degrees in a southerly direction, the strike being east and west approximately. Work was commenced here about two years ago by sinking an underlie shaft on the vein, which appears to occur at the junction of sandy granite and an altered rock. The shaft was sunk to a depth of 30 feet on the underlie * and a drive was put out a distance of 20 feet from the bottom of the shaft. 134 At the end of the drive the vein disappeared, giving place to a “ dig,” with traces of molybdenite and quartz. This may, of course, be merely a local pinch. Mr. Finch describes the molybdenite as being contained in the small quartz veins in the form of small but abundant flakes with copper pyrites. Kirk' » ( Z ..) Claim. — At Duckmaloi. Authority to Enter, of 10 acres, in Portion 164, Parish Norway, County Westmoreland. No infoimation is to hand concerning this deposit beyond the statement of the occurrence of molybdenite flakes. Information supplied by Mr. Warden Burke. O’Keefe’s Claim. See Glen Elgin. Old 25. See Kingsgate. Old 26. See Kingsgate. Old 45. See Kingsgate. One and Nine Ptpe. See Yates’ Pipes under Kingsgate. Orange. Molybdenite flakes in quartz and granite, in Portion 12, Parish Anson, County Bathurst. Mineral not reserved to the Crown. Information supplied by Mr. Warden Burke. Orchard’s Claim. See Bethungra. Outcast Mine. See Ardlethan. Packer’s Swamp. See Tantawanglo. Pambula. “ A band of this conglomerate runs along the east side of the intrusive por- phyry for more than two miles in the direction of the prevalent strike of the Coast and Black Ranges, which is towards south-south-east, and is distin- guished by veins of quartz with abundance of molybdenite on the road to Eden.”* Parker’s (W. H.) Claim. See Nambucca. Petrie’s (John) Claim. See Rocky River. Petrie’s (W. F.) Claim. See Rockv River. Pheasant Creek. See Glen Elgin. Pheasant’s Nest Mine. See Mount Metallic, under Whipstick. Piesse and Baker’s Lease. See Ardlethan. Potter’s Blow. See Sachs of Kingsgate, under Kingsgate. Pye’s Creek. See Bolivia. Queensgate Mine. See Black Range. Quinn’s Find. See Kingsgate. Reake’s Claim. See Gemalla, under Yetholme. Reef Blow. See Yates’ Pipes under Kingsgate. Reef Blow. See Sachs of Kingsgate. Reid and Weir’s Claim. See Boundary Creek, under Rocky River. Road Pipe (Sachs of Kingsgate). See Kingsgate. Road Pipe (Yates). See Kingsgate. Roberts and Hetss. See Rocky River. Robertson (E. H.). See Booroolong. * W. B. Clarke. Southern Gold-fields, p. 190. 135 The Rocky River or Wunglebung Deposits. The molybdenite deposits of the Rocky River or Wunglebung, are instruc- tive and interesting in that, although they fall under the head of “ pipes in granite,” nevertheless, as a group, they exhibit certain features peculiar to themselves. The locality lies about 26 miles south-east of Tenterfield, in a very deep and wild valley. The road leading from Tenterfield starts at a height above sea-level of 2,850 feet, and rises to a height of 3,100 feet above the same level in a distance of 11 miles. It has an indifferent surface and is of the switchback variety. Thence a descent of 2,000 feet is made to Demon Creek, the road on this section needing more cuttings to avoid the steep sidelings. From Billyrimba to Wunglebung, on the Rocky River, a distance of 6 miles, the, road is almost impassable in wet weather owing to the greasy nature of the yellow clay of the cuttings made in the dark felspar porphyry. Freight per ton to the railway at Tenterfield is said to be £4, or 3s. a mile. Wolfram, bismuth, and molybdenite, are the minerals mined, wolfram being found in greater quantities than either bismuth or molybdenite. These minerals occur in pipes of quartz or altered granite with pegmatite within coarse sandy and granular granite near its intrusive contact with two lava porphyries, one a dark felspar type, the other a light grey quartz-felspar type. The granite containing the pipes presents differences from those containing the important molybdenite and bismuth pipes of Whipstick, Kingsgate, Bolivia, and Deepwater. The latter, in common with the Rocky River types, are coarse, granular, and sandy, but they cut the associated clay- stones, slates, or porphyries, with sharp lines, there being little trace of variable or nondescript rock development at their margins. The granite of the Rocky River, in common with that at Rummery’s Claim (Fig. 9) intrudes the associated rocks in places only with clearly defined lines, while in other places it possesses a mantle of aplite, pegmatite, greisen, or siliceous material (PI. XXI). The coarse granite, also, of the main intrusion is more siliceous than the granites of the Bolivia, Deepwater, Kingsgate, and Whipstick, pipes, and indeed of other places in New South Wales containing molybdenite and bismuth pipes without wolfram and tin. It resembles the great siliceous or sandy granite of the Mole Tableland rather than the Kingsgate and other molybdenite granites. All of the granites of the district appear to have intruded Permo-Carbon- iferous sediments. The very sandy granites of Poverty Point containing gold pipes a few miles to the north form a high plateau east of Demon Creek, a tributary of the Rocky River. This high and rugged upland is flanked by “ dark granite ” types, containing abundant hornblende and sphene, and which the Poverty Point granite appears to have intruded. The floor of Demon Creek Valley, as also that of the Rocky River at Billyrimba and Wunglebung, consists of a felspar porphyry, whose base is very dark and almost flinty in texture. Near the leases worked for wolfram, molybdenite, and bismuth, the porphyry has been intruded by a granite mass, whose summit has been exposed by the denudation of the overlying and surrounding porphyry. The granite has only been exposed as to its summit (Plate XX). On the western side of the granite a quartz-felspar porphyry forms a rugged boundary. 136 The contrast between the granite and the dark porphyry is illustrated strikingly by the characteristic vegetation of the two formations. The porphyry, which decomposes into an extremely greasy clay, supports abun- dant growths of silver-leaved ironbark (Eucalyptus melanophloia) , grey box (E. hemiphloia), blue-gum (E. saligna), red stringybark (E. eugenioides ), red mahogany (E. resinifera), river red-gum (E. rostrata), red-gum (E. tereticornis) > tallow- wood (E. microcorys), ironbark (E. crebra), and other forest trees. Little or no undergrowth was seen on this rock type. The peculiar bluish-green colour of the foliage of the abundant silver- leaved ironbark was observed to end abruptly against the duller green of the sandy granite vegetation, the latter consisting of bloodwood (Eucalyptus Plate XX. Sketch geological map of Wunglebung Deposits. Rocky River, Parish of Wunglebung, County of Clive. corymbosa), brittle red-gum (E. dealbata ), red stringybark (E. eugenioides ), tea-tree ( Leptospermum scoparium) in thickets, clumps, and massed growths, native hickories and wattles (Acacia longifolia, A. penninervis, A. glau- cescens (?), A. nereif olia) and some beautiful shrubs with yellow pea blooms. To the immediate north the conical tops of several diorite intrusions are exposed in the bases of the deep and steep gorges, which make transport so difficult in this country. These cones are connected with each other pro- bably at a slight depth. They appear to have no connection with the molyb- denite and associated minerals. Several miles to the south, however, in the narrow bottom of a wild and rugged ravine, called Boundary Creek, three 137 knobs, dome-shaped, of sandy or siliceous granite form isolated outcrops. One knob is 200 feet in height, the others do not exceed 50 feet in height above the base of Boundary Creek. All have intruded the quartz-felspar- porphyry which forms so much of the country hence to Glen Innes, Deep- water, Bolivia, and Tenterfield. All are doubtless connected with one another, and with the Wunglebung outcrop at a depth. These sandy granites, particularly that exposed in M.Ls. 1 and 2, Parish Goolamanger, in Boundary Creek, are associated with wolfram and molyb- denite deposits. The distribution of the pipes and other deposits is shown on Pi. XXI, and in Fig. 22. The deposits occur within the sandy granite near its intrusive contact with the porphyry. An examination of the exposed granite humps suggest that here, in great measure, we have the original slope and surface of the granite summits, and that much of the flinty and siliceous debris of the surface, as for example, that seen in Goodwin’s lease, is part of the original mantle of the granite. Numerous pipes, unprospected as yet, dot this granite roof and suggest the tendency of the granite vapours to escape into the surrounding cooler rock masses, especially in the upper portions. The Whipstick granite is also a magnificent example of this action in the south-eastern portion of the State. History of Field . — According to Mr. Frank Roberts, it is believed that a hole 3 feet deep was sunk for gold about forty years ago on a large outcrop of quartz near Roberts and Heiss’ shaft, and known as “ The Quartz Blow.” Nothing of importance was found at the time, nevertheless had the prospectors continued the sinking for a few feet, they could not have missed the molyb- denite flakes which were scattered abundantly through the quartz. Mr. W. Smith, a selector, about the year 1912, found wolfram in what is now known as Goodwin’s Lease. This outcrop was then examined by Messrs. Scott and Lock, together with Mr. W. H. Yates, of Kingsgate. Mr. Goodwin, of Kingsgate, at a later date, proved it to be a quartz pipe containing wolfram and molybdenite. In September, 1913, Mr. Frank Roberts prospected the surrounding areas, and in company with Mr. Fred. Heiss, secured P.M.Ls. 1 and 2. A rich pipe was prospected by Roberts and Heiss, and a small plant for treating the ore locally was erected to offset the enormous transport charges to the railway (£4 a ton). Owing to the complex nature of the ore, this plant did not meet with success, and various parcels were sent to the Sydney Export Company for treatment. A. Boundary Creek . — The deposits of this locality were prospected about fifteen years ago by Mr. F. Heiss, who showed molybdenite specimens frou there to a local mining expert, by whom the mineral was said to be plum- bago and worthless. The prospecting operations were abandoned tempor- arily. Leases were taken up about 1914 on opposite sides of the creek, covering the small exposure of sandy granite in the base of the ravine (Fig. 22). The lessees were Mr. Percy Reid and Mr. Adams. The leases are 6 miles by very rough bridle track from Wunglebung. 1. Adams’ Claim. — P.M.L. 1, of 10 acres, Parish Goolamanger, County Clive. The granite is exposed as a knob or dome about 60 to 80 feet above the creek bed. This dome appears to be the original surface of the granite excrescence, and it is covered, in part, with the intruded porphyry. Small patches of rock containing wolfram, molybdenite, and hornblende, or similar material, have been found on the knob alongside the creek. Very little prospecting work. has been done on the lease. 138 2. Reid and Weir’ s Claim. — M.L. 1, of 20 acres, Parish Goolamanger, County Clive. The country is very rugged and steep, rising precipitously just beyond the creek. The granite (Figs. 22 and 23) outcrops only in the base of the ravine, and dips at a flat angle to the north-west, north, and east, under the quartz-porphyry, the greatest height above the creek bed of the exposure Fig. 22. Parish of Goolamanger, County of Clive. A — Outcrop quartz (pipe?). B — Granite and fine pegmatite containing molybdenite and wolfram. C — Pegmatite mantle, about 4 feet thick. D — Coarse siliceous granite. E — Filtered sediments and quartz -felspar -porphyry. N.W. 4 - J20yds_ SE. -> Sketch section across Boundary Creek showing the general relations of sediments to the quartz porphyry and the intrusive granite. 139 being only a few feet (Fig. 23). The granite is exposed for 225 to 250 yards in the left bank of the creek within M.L. 1, and at the widest point across both M.L. 1 and P.M.L. 1, it does not exceed 150 yards. On its northern or north-western portion for a length of 200 yards this granite has a mantle of coarse pegmatite, varying from 2 to 5 feet in thickness. Above this lies the porphyry or altered sediments, while below the mantle the coarse sandy and granular nature of the granite is apparent. This mantle gives place in the extreme eastern portion of the granite outcrop to a peculiar form of granite, lacking the coarse pegmatitic nature of the remarkable mantle further west. This eastern mass of ■silicified granite has a maximum length of 70 feet, forming a blunt wedge from 30 to 40 feet in width, and of unknown depth. The mass dips under the overlying porphyry at a low angle. From a heap of 100 tons moved from this mass of silicified granite, Mr. Hughie Weir states that 1 ton of wolfram has been handpicked, while a considerable amount of molybdenite and wolfram remains in the rejected material. The pegmatite mantle (Fig. 24) is studded irregularly with molybdenite and wolfram, but of very low grade. S.w. 25" N.E. - ^ - ‘—I Altered 'Sediments- - - _• ' Ma.nt.le of , coarse pegmatite^ containing ' ^ • — T flakes^- j Qf — „ molybdenite _ ^ Coarse + siliceous granite Fig. 24 (a). (a) Sketch section in Boundary Creek, Reid’s Claim, M.L. 1, Parish of Goolamanger, County of Clive. The granite dips to the north-west at a very gentle angle. At a distance of 40 yards downstream from the westernmost point of the lease (M.L. 1), a mass of quartz and coarse pegmatite outcropped in the rocky stream b?d A hole was sunk in this outcrop s ^ w i 220 yds about 3 or 4 feet deep, and about 8 feet across. The hole is now filled in great measure by stream debris, but according to Messrs. Reid, Roberts, and Weir, about 4 tons of stone were raised hence, from which 75 lb. of wolfram, and 1 ton of 4 per cent, molybdenite ore were handpicked, while 2 or 3 tons of stone lie on the surface apparentlycontain- ing about 2 Fig. 24 (b). Sketch section in Reid’s Claim, M.L. 1, Parish of Goolamanger, County of Clive, showing mantle of coarse and fine pegmatite exposed in workinrs in creek bank. A — Siliceous granite. B — Probable pipe of quartz. C — Thin mantle of coarse pegmatite containing molybdenite and wolfram. R — Fine pegmatitic granite containing molybdenite and wolfram. per cent. molybdenite. This quartz outcrop may represent a “pipe” in the granite, or again it may be only a prolongation of the pegmatitic mantle alongside. 140 It appears advisable to prospect this quartz and pegmatite further, and it also appears advisable to take samples across the large wolfram exposure at the eastern end of the granite, and to form some idea of the depth to which this ore body persists. If this body of granite really yields from 1 to 2 per cent, of wolfram it would be a valuable deposit. B. Wunglebung Deposits. — 1. Goodwin’s Claim, P.M.L. 3: — This lease is worked by Goodwin and Party, and covers very steep granite country, the granite being coarse and sandy. Several pipes outcrop on the hillside, but the deposit worked at present is indicated on the map (PI. XX), as No. 9, being a pipe of white quartz outcropping alongside a creek in precipitous country. The greater measurements of the pipe in cross-section are about 10 by 8 feet. In September, 1915, it had been worked to a depth of 30 feet along the dip, the latter being about 60 degrees. At this depth the pipe appeared to split. In February, 1916, the shaft was about 40 feet deep, and the pipe branches were seen to have united below what perhaps may be called a granite horse. The general arrangement of the minerals in the upper portion of the pipe In the typical cross-section the “ footwall ” portion varied from 1 to 4 inches in thickness, and was of compact, non-cavernous, grey quartz. In the “ gutter ” of the “ footwall,” according to Mr. Good- win, the bismuth occurs. The wolfram and molybdenite contents appeared to be arranged in the outer portion of the pipe, the wol- fram being developed, typically, in an outer, and the molybdenite in an inner, ring, the quartz enclosing them being compact and non-cavernous. The central portion of the pipe contained a large pro- portion of white quartz with a low wolfram and molybdenite content. Higher up the hillside a couple or more of very fine quartz out- crops are to be seen (PI. XX). These appear to represent a large pipe and its branches. These have not been prospected as yet. Production . — According to Mr. H. A. Goodwin, the production till the end of 1915 was 3 tons containing 65 to 67 per cent, tungstic acid, 15 cwt. containing 93 per cent, molybdenite, 1 cwt. bismuth. A heap about 7 tons in weight was lying at the mouth of the pipe. This appeared to contain about 1 per cent, molybdenite and a high content of tungstic acid, perhaps exceeding 8 per cent. 2. Petrie’s (John) Claim. — Now known as the Rocky River Wolfram and Molybdenite Syndicate, managed by Mr. G. F. Litchfield, P.M.L. 4, of 12 acres, Parish Wunglebung, County Clive. Adjoins Goodwin’s Claim (PI. XX). The country is of coarse sandy granite. On the map the deposit worked is indicated as No. 8. At the surface the deposit appeared to be a was somewhat as shown in Fig. 25. -+- -+ -H -H 4- Fig. 25. Idealised section across Goodwin’s pipe, as seen in 1915. A — Coarse siliceous granite. B — Light grey quartz containing wolfram. C — Milky and transparent quartz with ’ abundant flakes of molybdenite. D — Compact, white quartz, with very little wolfram, bismuth, or molybdenite. E — Compact grey quartz, non-cavernous, with a considerable amount of bismuth. 141 quartz vein of peculiar form. By following the quartz for a length on the underlie of 40 feet and a vertical depth of 22 feet it appears to have formed a small pipe about 3 feet in diameter. The quartz in the face, as seen in February, 1916, appeared to form the centre of the pipe, with molybdenite forming an outer zone. Wolfram occurred near the footwall. A small cracker and rolls driven by a whim horse is employed to treat the ore. The circle walked by the horse is about 22 feet in diameter, and the diameter of the drum is perhaps 3 feet. The plant is valued at £50. Production. — 1914. Not known. 1915. 25 tons of ore, estimated to produce 4 cwt. molybdenite, valued at £76. Wolfram also occurs with the molybdenite. 3. Petrie’s (W. F.) Claim. — P.M.L. 5, about 19 acres, adjoining Goodwin’s Claim (PI. XX) in rough granite country. Small prospecting holes have been sunk here upon quartz and other siliceous outcrops. Very little work has been done, and nothing was being done during my visits in 1915 and 1916. A large mass of impure quartz and granite occurs at the junction of the granite and porphyry alongside this lease as shown on Plate XX. The area appears to be worthy of prospecting. 4. Roberts and Heiss’ Claim. — P.M.L. 1, about 18 acres, and P.M.L. 2, about 9 acres, Parish Wunglebung, County Clive (PL XX). The leases occur in very rough country composed of siliceous and coarse granular granite intrusive into dark and light-coloured porphyries. The main workings are connected with the Rocky River at Wunglebung by a steep track about lj miles long. A considerable number of deposits are known to exist on the two leases, as maybe seen by a glance at the accompanying map (PI. XX). The deposit marked 3 on the map is a large wolfram pipe outcropping as a mass of tight granular quartz with encouraging prospects for wolfram. Deposit 4 is suggestive of a typical white outcrop of quartz at Kingsgate, and large flakes of molybdenite occur in abundance in the outcrop or quite near the surface. Deposit 5 is known as the Tin Pipe, and outcrops as a mass of quartz containing same tinstone, molybdenite, bismuth, and wolfram. Deposit No. 7 possesses a large outcrop of grey quartz with a fair wolfram content. It also possesses an outcrop of quartz and granite containing native bismuth and wolfram. Deposit No. 2 includes what appears to be a bismuth pipe, and a pipe outcrop containing much quartz and with a fair content of wolfram, molybdenite, and bismuth. .The deposit marked 1 is a quartz and granite pipe containing wolfram, molybdenite, and bismuth. The size of the pipe in cross-section appears to be about 10 feet x 6 feet. From the surface the deposit was followed in a direction about north 40° east, at an angle of 50 or 60 degrees to the horizontal. At a depth of 40 feet, as measured along the underlie, the pipe was found to have a direction of north 40° west, with a dip of 50 degrees. A vertical shaft 35 feet deep was sunk to facilitate mining operations. Near the bottom of the shaft the pipe was followed in a direction almost north 40° east. Excrescences, short processes, or vertical arms of quartz occur along the back of the pipe, and these are arranged in a manner such as to suggest the influence of a joint, or joints, in the formation of the main pipe. The prospectors, Messrs. Roberts and Heiss, appear to have been aware before- hand of the great bend in the pipe from north-east to north-west by 142 observing the changes in the arrangement of these vertical quartz processes or excrescences. Fig. 26 illustrates the arrangement of the minerals in that portion of the pipe exposed in the face, or bottom, in. September, 1915. Wolfram and bismuth occurred in a light grey and compact quartz at the lowest portion of the deposit or “ footwall,” while above this, about 2 ieet above the bottom, an assemblage of bismuth and molybdenite was seen with numerous long crystals of decomposed beryls. Above this was a rock material which appeared to represent granite altered to grey granular and compact quartz, and containing some wolfram and bismuth. A very compact, .granular quartz, grey in colour, and rich in wolfram was lying upon the altered granite, while above the wolfram a seam of molybdenite ore occurred, varying in thickness from 1 to 12 inches. The Hanging Wall, so-called, was composed of altered granite containing molybdenite, but no bismuth. In February, 1916, the pipe at the face was steep, while rich molybdenite, in seams, was visible in the roof. Wol- fram was also observed in fair quantity in the face. Production. — According to Messrs. Roberts and Heiss the production up till Dec- ember, 1915, was : — Wolfram. — 2 tons 5 cwt. (70 per cent, tungstic acid). Molybdenite. — 2 tons 12 cwt. (90 per cent, molyb- denite). Bismuth Sulphide. — 5 cwt. A large heap of ore, about 90 tons in weight, is lying at the shaft. This is very rich ore, possibly containing as much as 10 per cent, of wolfram, bismuth, and molyb- denite combined. A magnificent specimen of this complex ore is on exhibi- tion at the Mining Museum, Miller’s Point, Sydney. 5. Vaughan’s Claim. — P.M.L., 10 acres, adjoining Roberts and Heiss’ nlaim. The country is of granite, and contains certain siliceous outcrops, one of which is indicated on the accompanying map as No. 6, or the Mica Pipe. It is apparently a mass of granite which has been altered in great measure to soft secondary mica and impure quartz, the felspars especially being altered. It contains the usual association of minerals characteristic of the locality. Mr. Vaughan has sunk a certain distance upon the pipe, but no returns of ore won have been reported as yet. 6. Other Prospecting Areas. — Many other Authorities to Enter have been applied for within Portions 24, 38, and 48, Parish of Wunglebung, and several Authorities have been held also on Portions 6 and 8, Parish Goolamanger. From all of these molybdenite has been reported. Sketch section across face of Roberts and Heiss’ pipe in September, 1915. A — Coarse siliceous granite. B — Granite altered by silicification. C — Vein rich in molybdenite from 2 to 10 inches thick. D — Dense grey granular quartz very rich in wolfram. E — Granite altered to grey quartz, with wolfram and bismuth. F — Bismuth, wolfram, molybdenite, and beryls in light grey compact quartz. (Richest bismuth in “ gutter.”) 143 Future of Wunglebung or Rocky River Locality. — The locality as a whole is well worth careful prospecting. The leases already in force are deserving of careful and systematic work, particularly P.M.Ls. 1, 2, 3, and 4. The pipe at present being worked by Roberts and Heiss has only been worked to a depth along the underlie of 60 feet or thereabouts. Nevertheless about 5 tons of molybdenite, wolfram, and bismuth have been sent away, and apparently about 8 or 10 tons more of these minerals lie at the surface in the form of a rich complex ore. This indicates a very rich yield from a shaft 60 feet deep, and from 6 to 10 feet diameter. A good road to Tenterfield would help the district considerably. Ruming’s Claim. See Kingsgate. Rummery’s Claim. See Deepwater. Russ ,a nd Edward’s Claim. See Moonbi. Ryan’s (M. J.) Claim. See Lowther under Oberon. Rye Creek. See Burrowa. Sachs’ Folly. See Kingsgate. Sachs of Kingsgate. See Kingsgate. Sachs’ Old 45. See Kingsgate. Schaefer’s (H.) Claim. See Booroolong. Scott’s Reef. See Black Range under Bega. Serpentine River. See Guy Fawkes. Skeleton Creek. Twelve miles east of Glen Innes. Molybdenite flakes in granite. Infor- mation supplied by Messrs. Jamieson and Griffith, of Sydney. Snape’s (P.) Authority. See Booroolong. Slade’s Blocks. See Yetholme and Gemalla. Spencer’s (A. S.) Claims. See Laura Creek. Splitter’s Swamp. See Bolivia. Sproull’s Authorities. See Elsmore under Tingha. Staine’s Lease. See Wilson’s Downfall. Stalling’s Lease. See Wilson’s Downfall. Stanley’s (W.) Claim. See Booroolong. Stewart’s Point. See Nambucca. Sugar Loaf Mountain. See Wilson’s Downfall. Summerell’s Claim. See Tantawanglo. Sunrise Mine. See Bolivia under Cooper’s Claims. Sutherland and Party’s Claim. See Nambucca. Sydney Tin Mine. See Middle Creek under Tingha. The Tantawanglo Deposits. Topography. — The Monaro plateau from Cooma to Bombala andCathcart is high and bleak and is covered in the main with stunted growths of eucalypts. At a distance from the sea of 30 to 40 miles this wind-swept upland breaks away to the coastal lowlands by means of wild and tumul- tuous profiles. The main lines of descent to the coastal area are at the 144 Brown Mountain, the Tantawanglo, and the Big Jack, about 3,200, 2,600, and. 2, 200 feet respectively. From this great, but broken, eastern escarp- ment of the Monaro plateau long high spurs extend eastward. These east and west spurs, of which the Wyndham and Wolumla Mountains are examples, form watersheds between such rivers as the Bega and the Towamba. These spurs, in turn, mark residuals of the Monaro plateau which once extended with gradually-falling surface to the coastal ranges at Bega, Eden, Wolumla, and Tathra. The Bega and Towamba waters have excavated their own great valleys, and are now busily occupied in still gnawing their way headward into the great Monaro Plateau. At one time it was thought by the Writer* that the great eastern escarpment of the plateau had been due to faulting or warping of the coastal area, but upon personal examination of the area it was evident that the topography was due to stream action on:rocks of variable strength. One of the main points of descent of the range is the Tantawanglo Moun- tain, and the molybdenite deposits known as the Tantawanglo occur, for the most part, on the upper portion of the great plateau escarpment at this point. From the plateau towns, such as Bombala, Cathcart, and Cooma, the mountain is approached by good undulating roads, but the approach from Bega and Eden is by long steep mountainous roads, which, however, have fair surfaces. From Bombala, Cathcart, and Bega the Tantawanglo summit is distant about 18, 8, and 33 miles respectively. The whole of the great Tantawanglo Mountain is composed of siliceous granite, but the basalt of Monaro comes within a very short distance of the eastern escarpment of the mountain ah the summit of the road. Magnificent forests of gigantic eucalypts abound in the ravines and on the slopes of the mountain. The siliceous granite of which the mountain is composed is dotted here and there with very large segregations, or intrusions, of aplite and pegmatitic granite in which scattered molybdenite flakes occur as an original con- stituent. These deposits are very large, one being several hundreds of yards in length and several hundreds of feet in width at the surface. Nevertheless, there is no evidence as yet of any natural concentration into commercial deposits within these great outcrops. No pipes, nor veins, containing motybdenite have been found, and the deposits are altogether too poor to be worked as a whole. There thus appears to be little hope of mining these deposits at a profit. According to Mr. P. J. Knox, a resident on the summit of the mountain, the place was prospected for molybdenite about three years ago by Mr. W. J. Tarlington and another. They found specks of this mineral in M.L. 2. After this discovery Messrs. P. J. and T. Knox found specks of the same mineral on M.L. 4. M.L. 2 was then applied for. A prospector named Mr. Jessop meanwhile had found molybdenite on the area now covered by M.L. 6. Another prospector named Mr. Hammond found the mineral within M.L. 3. T. Knox then took up M.Ls. 5 and 9. M.L. 12 was taken up as a machinery site, and M.L. 10 was taken up at a date slightly later by Taylor and Adams. Another deposit found in the vicinity of M.L. 6 was A. L. Fulton’s in M.L. 8. * E. C. Andrew’s. The Geographical Unity of Eastern Australia. Procs. Roy. Soc. N. S. Wales, ■vol. XLIV, 1910, pp. 420-480. Plate XXL _.Pl. PLAN ^ SHOWING THE POSITION OF THE MOLYBDENITE DEPOSITS NEAR Scale L JTCha i t£s LAM AH 'bcfesi'tc. * fte G 1 ** PHOTO-LITHOGRAPHED BY W. A GULLICK, GOVT. PRINTfR, N.S.W. 145 All these occur in Parish Bredbendoura, County Auckland. Other deposits found in the neighbourhood were Summerell’s on Portion 95, Parish Creewah, County Wellesley, A. J. Fulton’s M.L. 1, in Parish Yuglamah, County Auckland, and It. H. Clarke’s claims on Packer’s Swamp, Parish Thoko, County Wellesley. 1. Clarke's Claim . — According to Mr. It. H. Clarke the deposit occurs about half a mile from the head of Packer’s Swamp, Parish Thoko, County Wellesley, about 9 miles from Holt’s Flat. The molybdenite occurs as scattered flakes in quartz and aplitic or pegmatitic granite, and according to the same authority the miheral has been found as at least six distinct out- crops over a distance of about a quarter of a mile. Some of the specimens forwarded to the Department of Mines by Mr. Clarke possess a fair percen- tage of molybdenite, but the average stone appears to be lew in grade. 2. Fisher's ( E .) Claim— This has been covered by M.L. 7 of 10 acres, Parish Bredbendoura, County Auckland. It is an area of siliceous granite in which infrequent flakes of molybdenite have been found. Very little pros- pecting has been done on this block. 3. Fulton's (A. G ) Claims. — These include M.L. 8 of 10 acres, in Parish Bredbendoura, County Auckland, and M.L. 1 of about 10 acres, Parish Yuglamah, County Auckland. The former of these is a mass of aplitic or pegmatitic granite surrounded by siliceous granite of more normal type. The outcrop contains scattered flakes of molybdenite. Prospecting opera- tions have been confined to the sinking of a shallow shaft and a little surface work. Nothing of commercial value has been reported. The second lease is in siliceous granite also, within which an outcrop of quartz and felspar occurs, containing flakes of molybdenite. A shaft has been sunk to a depth of about 20 or 25 feet, and some fair specimens of molybdenite and molybdic ochre have been obtained. Nothing of com- mercial importance appears to have been won as yet. [General information supplied by Mr. A. G. Fulton.] 4. Hammond' s Claim. — M.L. 3 of 20 acres, Parish Bredbendoura, County Auckland. This lease is in siliceous granite, within which a large outcrop of aplitic or pegmatitic granite has been found, containing flakes of molybdenite. [Information supplied by Mr. P. J. Knox.] 5. Jessop's Claim. — M.L. 6 of 10 acres, Parish Bredbendoura, County Auckland. The country is of siliceous granite, and in the southern portion of the lease an outcrop of aplitic or pegmatitic granite occurs, about 200 feet in diameter. As in all the Tantawanglo deposits, this aplitic type is of fine texture. Molybdenite occurs throughout the outcrop in small scattered flakes, without concentration at any particular point. Prospecting opera- tions have been confined to surface napping and to the sinking of several holes about 12 feet in depth. 6. Knox's Claims. — These consist of M.Ls. 2, 4, 5, and 9, which were taken up by Messrs. T. and P. J. Knox after prospecting. (a) M.L. 2, 10 acres, Parish Bredbendoura, County Auckland. The lease is connected by fair bush track with the main road near the summit of the Tantawanglo. The country rock is a siliceous granite, which appears to be traversed by a mass of aplitic and pegmatitic granite about 400 yards in length and 150 yards in width. This granite is fine in texture, and it contains numerous small holes and small patches of quartz. 146 Small flakes of molybdenite are scattered with a sort of regular irre- gularity throughout the aplite, but no concentration into pipes, veins, or large patches or “ bungs,” has been proved. Nowhere has any one mass of, say, 10 tons of stone in situ been found which contains more than one tenth of 1 per cent, of molybdenite. Prospecting has been confined to the breaking of surface stone, and to the sinking of shallow holes in the great outcrop. (b) M.L. 4, 20 acres, Parish Bredbendoura, County Auckland. The country rock of the lease is siliceous granite, the whole area being covered with a dense forest of magnificent eucalypt growths. In the southern portion of the lease a small knob of aplite or pegmatitic granite- outcrops. This is about 200 feet in diameter. The aplite contains numerous tiny holes or druses, and small thin flakes of molybdenite are scattered throughout the aplite as an original constituent, but without being concentrated into pipes, veins, or large patches at any one point. The average molybdenite content of the deposit is exceedingly low probably less than one-tenth of 1 per cent. Aid was, however, granted the prospectors from the Government Prospecting Vote, as it was deemed advisable to give this new field a fair trial in the hope of discovering something of commercial value below the oxidised zone. With this aid a shaft was sunk 75 feet, and a cross-cut put out for a distance of 50 feet. From the stone mined,, about seven or eight bags of low grade molybdenite ore were won by hand-picking. The stone tested by sinking and cross-cutting appears to be very similar to that exposed at the surface. (c) M.L. 5, 20 acres, and M.L. 9, 10 acres, both adjoining each other,, and in Parish Bredbendoura, County Auckland. According to Mr. P. J. Knox these leases both contain outcrops of molybdenite ore in siliceous or sandy granite, very similar in general character to the occurrences in M.Ls. 2, 4, 6, and 8. 7. Summerell’s Deposit . — Portion 92, 40 acres, Parish Creewah, County Wellesley, private land. From 3 to 4 miles north-west by good road from the summit of Tantawanglo Mountain at Hammond’s. The occurrence is in the sandy or siliceous granite of the Tantawanglo, andfrom specimens secured thence by my colleague, Mr. Leo Jones, and from descriptions also by Mr. J ones, the occurrence appears to be quite similar to the Tantawanglo deposits described above 8. Turlington s Deposit. — M.L. 12, 20 acres, Parish Bredbendoura, County Auckland. The area is composed of sandy granite, with a few flakes of molybdenite. A fine stream of permanent water traverses this lease, and it is said that the main value of the area would be to provide water for the treatment of the ore mined in the adjoining leases. 9. Taylor and Adams' Deposit. — M.L. 10, 15 acres, Parish Bredbendoura, County Auckland This deposit lies about three-quarters of a mile to the north from the summit of the Tantawanglo at Hammond’s. The country is of sandy granite, and molybdenite flakes occur within it, apparently as an original constituent. The occurrence is similar in general character to the neigh- bouring Tantawanglo deposits. A shaft about 21 feet deep has been sunk on the outcrop. 147 T arana. See Yetholme. Taylor’s Lode. See Mole Tableland. Ten Mile. 'See Deepwater. The Tenterfield Deposits. These are all unimportant, and include the various occurrences around Tenterfield itself, at Bungulla, and at the Bluff. A long undulating valley, from 3 to 15 miles in width, extends from a point 8 miles north of Tenterfield to Bolivia. This valley is bounded in all directions by high, rugged walls. The valley rocks are composed of the “ Blue Granite ” of northern New England, the sphene- hornblende granite of New England, and, in a very subordinate degree, the molybdenite granite of Bolivia. To the north this valley wall consists of the sandy tin granites of Boonoo Boonoo and Stanthorpe districts ; to the west the wall consists of the wolfram granite of the Mole River; to the south the tin and wolfram granite of the Bolivia cuttings bounds the valley ; while to the east the high and rugged Main Divide cuts off the valley. The latter is formed of quartz-felspar porphyry. From a point one mile south of Tenterfield the Great Northern Railway follows the sphene -hornblende granite porphyry for a distance of 15 miles towards Bolivia, hugging its junction with the intrusive wolfram granite forming the rugged hills to the west. In these hills of coarse and fine sandy granite, numerous small deposits of molybdenite occur. In other places large dykes or tongues of the sandy granite have intruded the darker granites of the main valley floor described above, and in places these sandy granite tongues are traversed by tiny quartz veins containing scattered flakes of molybdenite. Bluff {The) or Bluff Land. — Small deposits of molybdenite have been recorded from Portions 33 and 56, Parish Bluff Land, County Clive. The mineral appears to occur in granite. Bungalla. — Several small deposits occur about 2 miles to the north-west of Bungulla Siding, in the fine sandy granite. The more noticeable of these which have been prospected are contained in James Chorley’s and Michael Donnelly’s C.L’s., being Portions 32, 34, 46 and 78, Parish Strathearn, County Clive, and about 7 miles south-south-west of Tenterfield. According to Mr. F. Chorley, the molybdenite occurs as flakes in small quartz veins through the sandy granite of both Chorley’s and Donnelly’s land. Tenterfield.— Mr. C. S. Wilkinson, a former Government Geologist, reported as follows on a molybdenite ore from this locality* : — “ A yellow, friable, ochreous mass of carbonate and oxide of bismuth, with quartz and molybdic oxide, from Tenterfield, contained bismuth 43-29 per cent., molybdenite 6-60 per cent.” (a) Town Common, 2 miles west of Post Office. — Occurrence : As flakes in tiny quartz veins ( 7 ^- in. to J in. wide) in large acid (“ sandstone ”) granite dykes exceeding 1 10 yards in width, traversing blue granite. The dyke has, in cooling, contracted normally to its length, and the result- ing fissures have been filled with quartz containing molybdenite (vide dia- gram illustrating chapter on “ Hints to Prospectors”). (b) Tenterfield Creek, lj miles south of Post Office. — Occurrence : As flakes in an eurite dyke traversing alike the blue granite and sphene-horn- blendic granite -porphyry. This occurrence, as also that described in (a), is interesting, inasmuch as it proves the molybdenite to be a segregation of the granite dykes themselves. The molybdenite flakes occur in small * Mineral Products, New South Wales, 1882, p. 33. 148 lens-shaped pegmatitic secretions some 6 inches in length, shading off insensibly into the surrounding eurite. This type of dyke evidently repre- sents a fairly well-hydrated magmatic excretion. Small deposits occur also in the siliceous granites' in Portions 19, 22, 23, 28, 36, and C.P.L. 3,560, Parish Graham; in Portions 15, 101 and 102, Parish Glen Lyon; in Portions 2 and 7, Parish Addison; and in portion 6, Parish Ballandean, all in County Clive. Thompson* * * § s ( F .) Claim. — See Coronation Mine, under Deepwater. (c) W allangarra. — These occur in coarse and fine sandy granites near their intrusive contacts with basic granites and quartz-felspar porphyry. The deposits appear to be unimportant. They occur in Portions 27, 66 and 78, Parish Ballandean, County Clive. Tingha Deposits. Various unimportant occurrences of molybdenite within a radius of 20 miles from Tingha township are included under this heading. 1. Elsmore. — (a) The Elsmore Tin Mining Company (N.L.). Mr. J. E, Came,* Government Geologist, in reporting upon this tin property at Elsmore Hill, Parish Anderson, County Gough, states that “ the tin veins and the enclosing country also contain nests of wolfram, a little bismuth, molybdenite, and scheelite, the first-mentioned being the most common.” The granite at this locality is a sandy and siliceous type, containing a great development of greisen. Professor Liversidge| also mentions the occurrence of molybdenite with tinstone at the Elsmore and Newstead Mines. (b) The New Cornwall Lode.J — Portion 88, Parish Anderson, County Gough, “ about 1 mile south of Elsmore, on south side of Macintyre River. Outcrop not visible. Shaft sunk 200 feet in the early seventies, soon after tin -mining began. ... In the shaft spoil heap, the rotten granite still shows a, little tin associated with molybdenite.” (c) Molybdenite has been found in small flakes in unpayable quantities in various old tin workings near. Elsmore. Information supplied by Mr. Warden Perry. Mr. Leo Cotton§ has also described the Elsmore tin and molybdenite deposits. According to this writer they consist of numerous small inter- secting quartz veins in siliceous or tin-granite. Tin is the most important mineral in the deposits from a commercial point of view. “Wolframite,” according to Mr. Cotton, “ is found both crystallised and massive The wolframite is not abundant, for very little is obtained when cleaning the tin for market. Its total weight is less probably than 1 per cent, of the tin present at Elsmom ” “ Molybdenite occurs rather less abundantly than wolframite, and is to be found in small hexagonal flakes throughout the more siliceous parts of the veins.” (d) Applications by Mr. C. A. Sproull were made for Authorities to Enter on Portions 88 and 89. Parish Anderson, County Gough, to mine for molyb- denite. Information supplied by Mr. Warden Perry. * Tin Mining Industry, N.S. Wales. Mineral Resources, No. 14, 1911, p. 310. t Minerals of New South Wales, 1888, p, 71 . f J. E. Carne : Tin Mining Industry. Mineral Resources, No. 14, 1911, p. 220. § The Tin Deposits of New England, N.S. W. Procs, Lin. Soc. N.S. Wales, Vol. 34, 1909, pp. 733-781. 149 (c) Authorities to Enter have also been taken over portion of Portions 80, 83, 84 and 244, Parish Anderson, to seek for molybdenite. Very little prospecting work has been done. 2. Howell. — Conrad Mine. — Molybdenite reported as occurring in rare flakes in association with tin sulphide, galena, zincblende and quartz. Graham! s Claim. — M.L. 2, of 40 acres, on James Graham’s Crown lease of 1,798 acres, Crown lands, Parish Tienga, County Hardinge, about 8 or 10 miles westerly from Tingha, and about 4 miles from How'ell, near track to Bundarra. Molybdenite flakes in sandy granite. Very little prospecting work done. Middle Creek. — Mr. C. S. Wilkinson, a former Government Geologist of this State, reported* that “ in cutting a race through the granite of the Sydney Tin Mine, Middle Creek (between Tingha and Elsmore), a ‘ blow' ’ or sudden expansion of quartz was exposed. In the quartz I found abundance of fluorspar in imperfect octahedral crystals of an amethystine or greenish colour. With this were also galena, iron pyrites, and molybdenite. One small specimen I obtained with all these minerals together.” Tin Pipe. See Yates’ Pipes, under Kingsgate. Tompkin’s Gully. See Wilson’s Downfall. Torrington. See Mole Tableland. Tonkins’ Leases. See Gemalla and Yetholme. Towrang. See Goulburn. Turbet’s (W. and R.) Claim. See Mount Metallic. Twenty-Five Pipe. See Kingsgate. Twenty-Five East. See Kingsgate. Twenty-Five North. See Kingsgate. Two-Mile Creek. See Wilson’s Downfall. Vaughan’s Claim. See Rocky River. Walker’s Reefs. See Haystack Mountain, under Mole Tableland. Wallangarra. See Tenterfield. Wallendibby Mine. See Delegate. Warrell Creek. See Nambucca. Water Shaft. See Sachs of Kingsgate. Waterson’s (John) Claim. See Wilson’s Downfall . Waterson’s (J. F.) Claim. See Wilson’s Downfall. Watkin’s Claim. See Mole Tableland. Watson’s Lease. See Ardlethan. Wayne and Hamilton’s Claim. .See Bolivia. Webb’s Lease. See Lowther, under Oberon. Weir’s (Hughie) Claim. See Boundary Creek, under Rocky River. Wet Shaft. See Sachs of Kingsgate. * Mines and Mineral Statistics, N. S. Wales, 1875. p. 85. 150 The Whipstick Mines. The Whipstick Mines lie near the main road connecting the townships of Panbula and Bombala. From the former the mines are 15 miles, and from the latter 36 miles by mountainous road. Bombala lies on the Monaro plateau, while Whipstick lies among the coastal ranges, the descent from the plateau being made by way of Big Jack Mountain, down which the road descends 2,200 feet in about 4J miles. The mines may be approached also by steamer, the port being Merimbula, distant 18 miles from Whipstick, ■via Panbula. Another route is by motor for 75 miles from Cooma to Bega, by way of the Brown Mountain, thence by motor 22 miles to Panbula, and thence by coach to Whipstick. The greater portion of the area for a radius of from 30 to 50 miles from Whipstick consists of Devonian sediments which have been intruded by granites, and over both of which, in the plateau area, Tertiary basalts have been poured. The granite, which is mainly a dark hornblendic variety, containing numerous basic segregations, intrudes, but underlies, the Devonian sediments, the latter, with few exceptions, forming the summits of the hills and mountains. The granite at Whipstick itself, however, appears to be younger than the basic type of the district. From a consideration of the general arrangement of the massive conglomerate, grit, sandstone, and other beds composing the Devonian sediments, the granites, both basic and siliceous, appear to have their upper surfaces approximately parallel to the bedding planes of the enclosing sediments. On the other hand the granites of this great area may be seen to have burst through the old roof of sediments in various places, while sills are of common occurrence. The description* of one portion of this region, namely, Wolumla, by Mr. J. E. Carne, Government Geologist, together with the sketch section accom- panying his report, and reproduced on PL VIII, is characteristic of the Whip- stick, Bega, and Candelo districts. “ The principal physical feature of the Wolumla district is an extensive granite valley almost completely surrounded by an elevated rim formed by the Wolumla, Black, Mumla, Bemboka, and Tantawanglo Banges. The high lands on the north and west, towards Cobargo and Tantawanglo, are chiefly granite, while those on the south and east are mostly of sedimentary origin. The latter dip gently off, and away from, the granite of the valley. “ It would appear, from existing phenomena, that the granite originally Tose to a considerable elevation over the site of the present valley, lifting a portion of the western edge of a great sheet of accumulated sediments from the coastal margin of the oceanic basin in which it had been deposited. During the uplift, which evidently was effected without any violent de- rangement of the strata, the basal bed (conglomerate) in contact with the granite was baked and hardened, quartzitic characters being developed in the sandy paste in which the pebbles are embedded. Extensive vertical joints in the conglomerate probably attest the strength of the tangential strain of the uplift, more than shrinkage caused by desiccation. “ Where the gold deposits occur a section of the uplifted strata has been tilted to a high angle, and partially engulfed in the granite magma, portions of which have been squeezed upwards through numerous joints and fractures in the sedimentary rocks, crushing and saturating them. The dynamic energy of the intrusions has also left its impress on the extruded granite, * Annual Report, 1897, pp. 162-167. 151 for it presents a crushed and sheared appearance in the mass, and a waxy or chitinous aspect on closer view, owing to the felspars having been converted into a felspathic paste “ Though apparently the granite originally formed a huge boss-like mass over the present Wolumla Valley, it was not isolated from the extensive outcrop trending southerly beyond the Victorian border, and westerly to the Monaro tableland. “ From the relative positions of the granite and the sedimentary rocks between it and the coast, it would appear that the original line of weakness marked by the former was coincident or closely parallel with a shore line of a Devonian sea. The sedimentary rocks betray their shallow marginal origin by massive conglomerates and ripple-marked sandstones “ At Wolumla, the western margin of the beds caps the ranges, and with the one exception of Momsen’s Hill, the dip is at a low angle eastward and southerly of the granite, which outcrops on the western flanks and in the gaps and valleys between the ranges and peaks. At Momsen’s Hill, where the exceptional dip occurs, the beds have been tilted to an angle approaching the vertical “ Data collected in the Wolumla district not only confirm the previously- expressed opinion in my Pambula report that the quartz-felsite and rhyolite of Eden and Pambula are partially intrusive in the overlying Devonian series, but also demonstrate that the granite is likewise younger and intimately connected with the abovementioned acid eruptives.” Before describing the geology of the siliceous granite at Whipstick Mines themselves, the following note* by Mr. E. F. Pittman, A.R.S.M., Government Geologist, dealing with the bismuth deposits, may be here inserted : — “ The Jingera Mineral Proprietary Mines . — These mines are situated at Whipstick (near Wyndham), about fourteen miles to the west of Panbula, and are at the present time producing nearly all the bismuth raised in New South Wales. In their character and mode of occur- rence the deposits are very similar to those of Kingsgate and Pheasant- Creek, from which they are distant about five hundred miles. They consist of more or less cylindrical pipe-veins, which have a very irregular course and inclination, and which intersect granite rocks in proximity to their junction with slate. The filling of the pipes, however, instead of consisting entirely of quartz, as is the case at Kingsgate, is composed of a coarsely crystalline admixture of felspar and quartz, with a little mica, and occasional bunches of garnet rock. At least six of these pipes have been found, and they are all situated in proximity to a dyke (about four or five feet wide) of trachyte, which intersects the granite. The maximum diameter of the pipes is about fifteen or twenty feet, and the area within which they have, so far, been proved to occur is about two acres. The minerals which occur disseminated through the matrix are native bismuth, sulphide of bismuth, carbonate and tri oxide of bismuth, and molybdenite. No wolfram has been found in these deposits. Quite recently a fine patch . of native bismuth, weighing four hundredweight, was found associated with white quartz in one of the pipes, but as a rule the sulphide is the more common ore met with at a depth, while the carbonate and oxide occur near the surface. * Mineral Resources, 1901, pp. 261-262. 152 “In 1891, shortly after the mines were opened, an isolated patch of ■extraordinarily rich ore was discovered close to the surface. It weighed three and a half tons, and was forwarded to Sydney for examina- tion. After the parcel had been crushed and thoroughly mixed, a sample was assayed in the Laboratory of the Department of Mines, and yielded as follows : — Metallic bismuth, 23-34 per cent. Fine silver, at the rate of 1,108 ounces per ton. Fine gold, at the rate of 11 dwt. 23 gr. per ton. “ Further prospecting failed to reveal the source whence this apparently isolated bunch of ore was derived. One or two instances, however, of narrow but highly argentiferous veins have been discovered, and in 1893 the company exported thirty-one tons of argentiferous bismuth ore, which yielded three and a half tons of metallic bismuth, twelve ounces of gold, and 6,107 ounces of silver. An auriferous quartz reef also occurs in proximity to the bismuth pipes, and four tons extracted from this are said to have yielded at the rate of an ounce of gold per ton; on being followed down, however, the stone became poorer, and ceased to be payable. “ The mines have been worked principally by a tunnel which has been driven in a straight course, and when pipes have been intersected by it they have been followed laterally, or vertically, as the case might be. From one of these pipes more than six hundred tons of ore have been extracted.”* General Geology. — The Whipstick mines, as mentioned earlier by Mr. E. F. Pittman, occur in granite near its contact with sedimentary rocks. Unlike the granite of Bega, Bemboka, Candelo, Rocky Hall, and the Big Jack Mountain, which are dark or basic types, containing much hornblende in stout crystals, and many dark inclusions, the granite of Whipstick is light- coloured and siliceous in nature The vegetation, however, is not so starved and stunted as might be expected from a sandy granite type such as the one under consideration. The general absence from Whipstick of stunted growths, which botanists usually associate with such poor soils, is to be explained in part by reason of the abundant and constant rainfall and in part also by reason of the rugged nature of the country, which consists of deep sheltered gorges .separated by high narrow ridges. Eucalypts of immense height and magnificent appearance form dense forest growths on the slopes, while brush growths of myrtles, tree ferns, and other plants, abound in the lower portions of the ravines. The main portion of the larger vegetation con- sists of the black ash ( Eucalyptus Sieberiana), mountain ash (E . Delegetensis), cut-tail (E . fastigata), stringybark (E. eugenioides, E. Muelleriana, E. capitel- lata, and E. obliqua), peppermint (E. amygdalina), white gum (E. viminalis), E. radiata, white hickory ( Acacia melanoxylon) , hickory (A. joenninervis ) , golden wattle (A. longifolia, in thickets), sunshine wattle (A. discolor ), A. decurrens , A. stricta, lillypilly ( Eugenia Smithii), dead finish ( Cassinia ), everlastings ( Helichrysum ), wild holly (Oxylobium trilobatum), and other types. The granite is coarse in texture, and consists of large and abundant grains of quartz associated with pink felspar and abundant plates of white mica. Near the contact of the granite with the Devonian sediments the white mica * Mineral Resources of New South Wales. 1901, pp. 201-262. 153 is much more abundant than in the main body of the rock, and, in certain places the mica content of the granite is such as to give the appearance of a mass of white mica. The sediments have been classed as Devonian by their lithological resemblance to those beds in the neighbourhood which have been proved to be of Devonian age by Mr. J. E. Carne. Moreover, by filling up the valleys of erosion in the ranges in imagination the sediments of the Whipstick Mountain may be inferred to have been continuous, at some former time, with the Devonian slate, sandstone, and conglomerate beds mentioned by Mr. Carne.* These sediments occupy the higher portion of Whipstick Mountain, while the siliceous granite forms the lower and middle portions to the west, south, and south-east of the mines, as may be seen on the accom- panying map and section across the area. (PI. XXII, and Fig. 27.) Parish of Wyndham, County of Auckland. D — Altered claystone. G — Siliceous granite. • Annual Report, 1897, p. 168. 154 Although the main granite and slate contact is well defined, nevertheless numerous small patches of sediments occur as isolated residuals upon the granite at slight distances from the main mass of the sediments. This feature is well illustrated in Young and Reid’s leases. The sediments have been intruded by the granite, as may be seen by the contact alteration of the Devonian sandstones to quartzites, of the claystones to knotted slates, by the development of minerals such as mica within the granite near the contact, and by the peculiar geological occurrence of the “pipes ” at Whipstick them- selves. The granite may have a laccolithic development over restricted areas. Numerous dykes of varying composition intersect the granite, and reference is made to these in the description of the mine workings. W. Pipes containing molybdenite ( Young Sr Reid ) Pheasants Nest Pipe containing molybdenite and bismuth at Altered Devonian ■ ofi s^hrr- contact of granite and sediments Siliceous 'granite Fig. 27. Sketch section across the Whipstick Mining area. The section illustrates the flatness of curvature of the granite surface, and the occurrence of the molybdenite pipes at and near the contact of granite and altered sediments. The accompanying figures illustrate some of the main geological features at and near the mines. The granite and slate contact forms a surface which is fairly flat, and the molybdenite deposits appear to occur close either to a present or former roof of altered sediment, and, what is significant, there is a suggestion from the mining workings themselves that the “ pipes ” have branched as they approached the sedimentary roof. {See Map.) A study of the outcrops in the Mount Pleasant, the Metallic, the Whipstick Mines, Limited, and Young and Reid’s blocks does not indicate that each group of pipes is related to any definite geometrical plane, nevertheless a study of the lower workings of the Whipstick and Metallic Mines indicates that each group of pipes, considered separately, commenced at a considerable depth below the intrusive granite contact from a common source and that as the pipes approached the granite margin they branched in various directions from the single lower source. Mineralogical Notes on the Pipes .— The pipes of the Whipstick Mines, Limited, and the Metallic Mines may be taken as types of the deposits in the locality. In the Metallic group the Gold Pipe outcropped as a manganese gossan and a rock composed, in the main, of white mica in fairly coarse flakes. This mass was of the nature known to miners as kindly, being soft, friable and drusy. So much manganese ‘was present in this, and other outcrops, that specimens have been forwarded to the Departmental Laboratory for analysis as manganese ores. Gold was found in this outcrop in quantities sufficiently rich to repay working expenses, but little or no bismuth appears to have been noted. In the bismuth pipe, or branch, of the same mine the outcrop consisted of a mass 155 of manganese gossan with molybdic and bismuth ochre. At a depth from 20 to 30 feet below the surface the sulphides of molybdenum and bismuth were found, and here the manganese gossans disappeared almost entirely, their place being taken by a transparent granular form of garnet, occurring in large and small bunches scattered throughout an altered form of siliceous granite. This altered granite forms the greater portion of the pipes of Whip- stick. In places the texture of the granite has not been altered in any marked degree, but silicification has gone onto such an extent that much of the felspar content has been replaced by granular quartz, white mica has been developed abundantly in places, while molybdenite in crystals and rosettes, native bismuth, sulphide of bismuth, and garnet, both massive and crystalline, have been developed throughout the granite. This apparent alteration seems to have been most intense at the more central portion, or longer axes, of the pipes, and it has died away in such a manner as to have caused the pipes to become large and approximately elliptical in cross-section. Beyond these limits there is a gradual transition into the unaltered granite of the country. The No. 3 pipe of the Whipstick Mines had a massive cap of manganese gossan, which disappeared at a vertical depth of 40 feet, approximately, from the surface. At this depth the manganese gossan gave place to altered granite containing large patches of reddish garnet. Molybdenum and bismuth ochres occurred abundantly below the surface, but it was not until a depth of 30 to 40 feet had been reached below the surface that the clean sulphides were found. A similar association of minerals is reported from the upper portion of the No. 1 pipe, which outcropped on the steep hillside below the No. 3 pipe. In both of these pipe branches the rock was very similar in appearance to that of the pipes of the Mount Metallic Mine in the vicinity. At a considerable depth below the outcrop of No. 3 pipe or branch, other pipes or branches were worked. The ore in these resemble that in Nos. 1 and 3 branches. Among these branches or pipes may be mentioned No. 2, or the Main Pipe, Nos. 5 and 6. ( See accompanying Maps.) On the sketch map of the plans and sections of Whipstick Pipes, in “ Plan at F” the No. 6 pipe has been labelled No. 2. This is incorrect, because the No. 2 pipe has disappeared at this level F. At the No. 2 or upper level also, the branch, known as the Pilot, was seen. This consisted of a tortuous cylinder of quartz, brittle and white, and quite distinct in appearance from the pipes of altered granite associated with it. A ring or zone of garnet rock surrounded the quartz axis of the Pilot for a width varying from 2 to 12 inches. The Pilot does not appear to have contained molybdenite or bismuth in considerable quantities. At a depth of 215 feet below the lower or No. 1 Level (see Maps), the pipes known at the present time are only two in number and are close together. The main pipe, No. 2, is here the usual altered granite, consisting in places of a granular aggregate of quartz, with a slight admixture of felspar in the central portions. At a depth of 260 feet below the No. 1 or low-level tunnel the No. 2 Pipe is composed of a very siliceous granite with garnet. At a depth of 215 feet below No. 1 tunnel, a garnet pipe was found in contact with the No. 2 or Main Pipe. This was found to be about 25 feet in longer diameter of cross-section, and perhaps 20 feet in greatest width in cross-section. Instead of being composed of granite it was found to be a mass of granular garnet, fine in texture, and containing large patches of quartz with native bismuth, sulphide , of bismuth, telluride of bismuth or Joseite, and molybdenite. Appended are analyses of both pipe granites and the Joseite by Messrs. H. P. White and W. A. Greig, of the Departmental Laboratory, under the supervision of Mr. J. C. H. Mingaye. The granite of the country contains about 74 per cent, silica. 2515. — Biotite granite from Whipstick Mine. 2516. — Granite from Whipstick Mine. 3336. — Muscovite granite, from Whipstick Mine, near mouth No. 1 tunnel, 450 feet from pipe. 2515. 2516. 3336. Chemical Composition. Per cent. Per cent. Per cent. Silica ... 83-54 87-66 75-02 Alumina ... 9-13 7 32 1377 Ferric oxide... ... 0-50 0-30 1-40 Ferrous oxide ... 0-36 absent 0-27 Magnesia ... 0-30 0-08 0-04 Lime... ... 0-46 absent 0-12 Soda ... ... ... ... ... 3-51 3-58 3-29 Potash ... 1-14 0-20 4-78 Water (100° C.—) ... 0-10 0-02 0-07 Water (100° C. + ) ... 1-14 0-36 1-17 Carbon dioxide . . . absent 0-05 absent Titanium dioxide ... . . . *trace absent 0-30 Zirconia dioxide ... absent absent absent Phosphoric anhydride ... 0-05 0-02 0-03 Sulphur trioxide ... 0-04 absent absent Chlorine ... 0-04 * trace absent Fluorine ... . . . absent absent absent Sulphur ... ... absent 0-16 absent Chromium sesquioxide . . . absent absent absent Nickel and cobalt oxides ... . . . absent absent absent Manganous oxide ... . . . absent # trace 0-02 Barium oxide ... absent *trace absent Strontium oxide ... f present absent absent Lithia . . . absent fpresent fpresent Vanadium oxide . . . absent absent absent Copper ... absent absent absent Bismuth ... . . . absent 0-54 absent Lead ... absent absent absent Molybdenum ... *trace *trace absent 100-31 100-29 100-22 Specific gravity ... 2-666 2-646 2-633 * Les? than 0-01 rer cent. f Spectroscopic reaction only. Gold, nil Silver, a trace j- 2515 Gold, nil Iqkir Silver 4 dwt. 8 grs. per ton f 0 ° 2515 — Analysis by W. A. Greig. 2516— „ H. P. White. 3336— „ H. P. White. 2050. — Mineral picked from native bismuth with telluride and sulphide of bismuth in glassy quartz and garnet material. The analysis indicates the mineral to be Joseite. Analysis by J. C. H. Mingaye. Per cent. Bismuth 82-92 Tellurium 9-16 Selenium ... trace Sulphur 6-19 Manganese ... 0-77 Iron ... 0-47 Gold ... ... ••• absent Silver ... ... ... absent Insoluble matter 0-32 99*83 Specific gravity — (1) 7*793; (2) 7-688 157 Origin of Pipes . — From a knowledge of these facts, combined with a study of the accompanying plans and sections, it would appear that the pipes have been formed subsequently to the general consolidation of the granite in its more marginal portion ; that each group of pipes has been formed from some centre within the cooling, but still hot, granite, that the pipes have branched as they approached the surface ; that the alteration of the granite in part, if such alteration did occur, proceeded from a series of tortuous lines now forming the longer or vertical axes of the pipes; and that the alteration has been such as to introduce much silica, manganese, sulphur, and perhaps water, with certain amounts of molybdenum, bismuth, tellurium, selenium, gold, silver, and iron, into the siliceous granite. It has been stated already that there is no trace to the unaided eye of joint planes which might have afforded a passage for ascending hot vapours carrying minerals in solution, nevertheless the evidence of the collinearity of the main axes of the Nos. 1, 2, and 3 pipes is so striking, as is also the evidence of the transition from ore to granite in radial directions as measured from the longer axes of the pipes, together with the “ step-and-tread ” nature of certain pipes, as may be seen for No. 3 Pipe in the map, that it appears justifiable to infer the action here of vapours, expelled from the cooling granite, containing molybdenite, bismuth, silica, manganese, and other minerals, all exceedingly mobile under the action of great heat and pressure. These vapours may be inferred to have been working their way from a region of high pressure, namely, the heated granite, to a region of less pressure, namely, the cooler sediments near the contact zone. The penetrative powers of the vapours under these conditions were such that they could ascend planes or zones of weakness in the cooling granite not visible necessarily to the naked eye, especially at points where these planes had been inter- sected by microscopic cross-joints. These ascending vapours would naturally find less resistance to their progress as they neared the granite contact with the slate, and thus branching might be expected, with deposition of the molybdenite, bismuth, gold, silver, and other contents in the less heated granite margin, much in the same way that sulphur, copper, bismuth, zinc, and certain other minerals may be deposited from fumes in the cooler portions of chambers or chimneys leading from a smelting furnace. This idea of the pipes being due to replacement agencies is also suggested by the very variable degree of alteration, or mineral composition, which the pipes present, not only in the various members, but in the same individual. Thus it is remarkable how a large pipe, as much as 25 feet in diameter, may disappear overhead as a mere thread, or a tiny joint carrying molybdenite, or how such a deposit may appear to disappear as an insignificant and irregular body when traced in a horizontal direction, while it may reappear in another place as a great impregnation. The Pilot, the Nos. 1 and 2 pipes of the Whipstick, and the Gold and Bismuth pipes of the Metallic may be taken as types of this supposed variable alteration of granite by vapours containing various elements in solution. The Gold pipe of the Metallic Mine appears to represent an alteration of the felspars of the granite to mica; the Nos. 1 and 2 pipes appear to represent stages more advanced than the introduction of mica. In these deposits the mica does occur, but only in subordinate amount. A marked sihcification is noted in these pipes, and a considerable development of garnet. In the Pilot, on the other hand, an alteration, almost completely to quartz, may be noted, the core and main portion of the deposit consisting of white brittle quartz, while the margin, or 158 collar, is of garnet, or rarely of mica. In the opinion of the Writer, the Pilot- consisted, at one period, of a granite containing about 74 per cent, silica; at a later period vapours ascended along intersecting vertical joints of very small dimensions. These altered the granite surrounding the joint inter- sections in a manner such that their intensity decreased in a radial direction, within any horizontal section. They gradually replaced the felspars of the granite by fine flakes of hydrous mica. These, in turn, were replaced by garnet masses and by silica, which became more or less continuous with the quartz grains originally in the granite. This granular quartz, garnet and mica admixture gradually became replaced at and near the linear core by a white brittle quartz, the latter being encircled by a collar of .garnet in places, of hydrous mica in other places, each dying away into an encircling zone of granite, showing felspars invaded by mica specks and flakes. This- association in the Pilot does certainly suggest a decreasing intensity of altera- tion in granite in a horizontal direction from the general direction of the twisted linear core of the pipe. History of Whipstick Mines . — The following notes on the earlier history of the Whipstick Mines have been derived in part from Mr. Pittman’s* notes on the field, in part from information supplied by Messrs. R. Vernon. Saddington and R. Y. Medcalf, and in part from notes supplied by Mr. W. H. Yates, of Kingsgate. Bismuth ore appears to have been discovered in 1891 on the slope of the Whipstick Mountain, overlooking Merimbula. Eight leases, totalling 203- acres in area, were taken up then at this locality by the Great Jingera, Proprietary Silver-Mining Company. According to Mr. E. F. Pittman, f it appears that “in 1891, shortly after the mines were opened, an isolated patch of extraordinarily rich ore was discovered close to the surface. It weighed three and a half tons, and w^as forwarded to Sydney for examination. After the parcel had been crushed and thoroughly mixed, a Sample was assayed in the laboratory of the Depart- ment of Mines, and yielded as follows : — Metallic bismuth, 23-34 per cent. Fine silver, at the rate of 1,108 oz. per ton. Fine gold, at the rate of 11 dwt. 23 gr. per ton. “ Further prospecting failed to reveal the source whence this apparently isolated bunch of ore was derived. One or two instances, however, of narrow, but highly argentiferous veins have been discovered, and in 1893 the Com- pany exported thirty- one tons of argentiferous bismuth ore, which yielded three and a half tons of metallic bismuth, twelve oz. of gold, and 6,107 oz. of silver. An auriferous quartz reef also occurs in proximity to the bismuth pipes, and four tons extracted from this are said to have yielded, at the rate of an ounce of gold per ton.” The accompanying notes on the history during the period 1891-1896 were supplied by Mr. W. H. Yates, of Kingsgate : “ Near the summit of the spur or range (about 1,000 feet above the flats at the foot), a small excavation, about 4 feet deep by, say, 6 feet by 6 feet, had been made in the soft decom- posed surface granite, which showed for a width of, say, 2 feet, a considerable quantity of bismuth- carbonate in fine grains, well disseminated, and said to be rich in silver. • E. F. Pittman. Mineral Resources, 1901, p. 262. t Op. cit., p. 262. 159 “ A large area of land in 40-acre mineral blocks had been taken up. Seven or eight of these blocks, including the rich find near the summit, were amal- gamated and held by a syndicate. This was the position in September, 1891. “ The rich ore near the summit was followed on its dip for about 10 feet, where it disappeared abruptly against a well-defined quartz reef running north-east and south-west. The miners were unable to trace the ore beyond this, and horizontally the impregnation did not extend. About four tons of ore were obtained here, averaging about 24 per cent, of bismuth and 1,200 ounces of silver a ton. This ore was sent to Germany. After this the Company sank 30 or 40 feet on the quartz reef, but found no bismuth, although it was said to contain silver and gold in payable amount. A tunnel was then driven into the hill in a south-east direction to cut the quartz reef about 100 feet below the outcrop whence the rich ore patch had been taken. The estimated length of this tunnel, prior to driving operations, was 300 feet. At a point 115 feet along the tunnel from its mouth, granite carrying bismuth was cut unexpectedly. This formation was found to continue into the hill, in patches, for 30 feet, the bismuth occurring as sulphide disseminated in particles thickly through portions of the granite. Molybdenite occurred also in this material. It is stated that 50 tons of ore containing 10 per cent, of bismuth were obtained during 1892. “ The tunnel was continued, and at a distance of about 320 feet from the mouth the ‘Quartz Reef’ was cut, and was driven on its course south-west for 60 feet, but no bismuth was found in it. [It was a well-defined vein three feet in width.] The tunnel was driven a farther distance of 80 feet, making 400 feet in all, but nothing of commercial importance was found by this extra work.” “ About March, 1893, the Company ceased operations entirely and the mine lay idle for about eighteen months.” The history of Whipstick for a considerable period subsequent to 1893 has been supplied by Messrs. R. Vernon Saddington and R. Y. Medcalf. In 1895 the mine was acquired by the late Mr. R. Saddington, in conjunction with Mr. E. W. Bathurst. A considerable amount of money was spent in developing the mine. Bismuth was sought primarily, and silver secondarily, while molybdenite, which occurred rather abundantly, was regarded as an impurity, inasmuch as it had no commercial value at that time. Nevertheless the bismuth had to be free from molybdenite admixture. At that time the ore was hand-dressed. Much of the ore contained as much as 10 per cent, bismuth, while small lots also contained silver as high as 1,000 to 1,200 oz. a ton. Arrangements were made, at a subsequent date, to supply Messrs. Elliot Bros, with 3,000 tons of bismuth ore, which was to be converted into metallic bismuth by the buyers. Difficulties, however, were experienced in fulfilling the conditions of the contract, and at last Elliot Bros, took the mine on tribute until the amount promised under terms of the original contract should have been mined. In 1897 the existence of a quartz reef, containing gold, was reported from the locality. This vein was prospected along the outcrop for a distance of about 100 yards. The gangue was a true quartz, slightly honeycombed, and crystallised in places. The gold was reported to be of heavy and shotty nature. 160 After the termination of Elliot’s tribute arrangements were made with Messrs. Charles Markell & Company, with the executors of the late Mr. R. Saddington, and with Messrs. Elliot Bros, to work the mine afresh and conjointly. The “ International Mines Ltd.” was thus formed, with a capital of £10,000 in 10,000 shares of £1 each. Mining was carried on with varying fortunes for a time, when, owing to the metal contents of the ore being won at the time dropping to about 0-60 per cent, bismuth, the Company ceased mining operations at Jingera. During the term that this Company was producing ore, the richer portions were sent to the works at Balmain, belong- ing to Elliot Bros. The low grade ore was concentrated before being despatched to Balmain to be converted to refined bismuth. A portion of the refined product was used locally, but the greater portion is said to have been sent to Messrs. Johnson and Matthey, in England. The accompanying notes dealing with the history of Whipstick during the past few years have been supplied by Mr. J. E. Scantlebury. The lease taken up by Mesrs. Marked & Company lapsed a few years ago, and it was then taken up by Messrs. T. A. Schafer and H. Robertson. In 1912 they raised 63 tons of molybdenite ore, valued at £500. The ore was hand-dressed and despatched to Germany for treatment. Messrs. Schafer and Robertson then gave a working option to a small group of mining men. During a period of twelve months the option had the right to remove ore either from the mine or the dumps on the basis of a 5 per cent, royalty. This syndicate, so-called, was merged subsequently into a company of 24,000 shares of 10s. each, of which 18,000 are said to have been issued and 6,000 held in reserve. This company is known as the Whip- stick Mines, Ltd. Production . — It is not possible to obtain a complete statement as to the production of molybdenite and bismuth from the various Whipstick Mines. In the earlier days of mining at this locality the molybdenite was cast aside for reasons already set forth. Moreover, the producers of bismuth main- tained a secretive policy, as far as possible, concerning the output and the price of this metal. The accompanying return has been compiled from the various official publications, but at the best it is only a statement which is far from being complete. The Whipstick Mines, Ltd . — In 1892 the Whipstick Mines, known then as the Great Jingera Silver- Mining Company, “ sent away to Europe 31 tons of argentiferous bismuth ore, which gave a return of 3| tons of bismuth, 12 oz. gold, and 6,107 oz. silver, of a total value of £2,343.”* “ In the Annual Report, 1897, page 42, it is pointed out that 1,430 tons of ore were raised during that year, of which 146 tons were sold and exported. The estimated value of the bismuth sold was £3,100, and that of the silver associated with the bismuth, £264.” f “ Mr. G. C. Elliot reports having raised 576 tons of ore from his mine at Whipstick, Jingera, during the year, which were treated in Sydney, some 10 tons of bismuth being produced.”! In 1901, 1902, 1903, it is reported that 20-8 tons, 10-15 tons, and 21-75 tons, respectively, of bismuth concentrates were produced in the State, the greater portion of which amount is said to have been won from Jingera (Whipstick). * J. A. Watt. Bismuth Ores of New South Wales. Mineral Resources, No. 4, 1898, p. 11. t J. A. Watt. Mineral Resources, No. 4, 1898, p. 11. j Annual Report, 1900, p. 64. PARISH 161 In 1904, bismuth concentrates to the amount of 40-3 tons were produced in the State. A large proportion of this came from the International Mines, Ltd. (Whipstick Mines, Ltd.) 1905. — 1,964 tons of bismuth ore. Value, £5,320. 1907. — 372 tons of bismuth ore. Value, £2,504. 1908. — 4J tons of bismuth ore. Value, £60. 1909. — Return unknown. 1910. Schafer and Robertson (Whipstick Mines, Ltd.) raised 60 tons of ore, which was not treated in 1910. 1911. — 3£ tons bismuth concentrate. Value, £479. j 68 tons bismuth ore. Value, £859. 1912 gg tons jnolybdenite ore. Value, £500. j 4 tons bismuth concentrate. Value, £739. 1913 j jg tons mo iybdenite concentrate. Value, £6,400. j 36 tons bismuth ore. Value, £1,742. 1914 | g tons molybdenite concentrate. Value, £5,000. j 17 tons bismuth ore. 1915 | |2 tons molybdenite. Valued at £6,000. J Till 30th June about 12 or 15 tons molybdenite. | 4 tons bismuth. The Mount Metallic Mine. 1904. — 850 tons of ore raised, yielding 5-05 tons bismuth concentrate, valued at £2,262. 1905. — 290 tons bismuth ore. Value, £544. 1906. — 230 tons bismuth ore. Value, £460. 1914 I ^ ^ 0nS concentrates. Value, £201. ( Molybdenite, not known. | 20 tons bismuth ore said to contain 3 tons bismuth, not known. ( 20 tons molybdenite ore, not known. The early returns of Whipstick were for bismuth only, but- they are recorded here in order to emphasise the amount of molybdenite rejected, inasmuch as the molybdenite content of the ore appears to be comparable with that of the bismuth. Descriptions of Mines. 1. The Mount Metallic Mines. — These embrace M.Ls. 45 and 49, of 40 acres approximately, Parish Whipstick, County Auckland. This area embraces the old mines known as the Mount Metallic and the Pheasant’s Nest. The deposits consist of mica, garnet, and granite, pipes with free quartz in large patches, all occurring either at or near an intrusive granite contact with altered Devonian claystone. All the deposits outcrop on a very steep hillside covered with brush growths. Between the outcrops of the old Metallic Mount and the Pheasant’s Nest there are indications of other pipe outcrops which may represent points of connection with the Pheasant’s Nest. The prospectors of the Metallic Mine came upon a patch of manganese gossan, with much white mica, forming a small circular outcrop on the hillside near the main granite and claystone junction. This was found to t 68791— F 162 contain gold. The deposit dipped steeply into the hill, and was followed with ease to a depth of about 80 feet by reason of its pronounced content of mica and gold. At this depth the pipe, or branch, proper was lost tem- porarily, but by following an irregular impregnation in a sub -horizontal and circuitous direction the prospectors are said to have come upon a bismuth pipe which rose steeply to the surface with a strong outcrop of garnet rock. This pipe, or branch, was not traced to a depth greater than about 60 feet below the surface. Prospecting was continued in various horizontal direc- tions by means of certain “ indications,” and this led to the exposure of various irregular impregnations. Finally, Mr. Schafer, a prospector,- was led to a pipe containing both bismuth and molybdenite, which dipped steeply in a fairly uniform direction. This pipe was prospected to a depth of about 100 feet below the point at which the gold pipe had been lost, but at a con- siderable distance in a horizontal direction. The prospects of this pipe I was unable to ascertain, inasmuch as there was a considerable amount of water in the bottom during my visit in 1915. A tunnel has been put in the hillside at the level of the base of the gold pipe so as to work all the connected openings. The Pheasant’s Nest deposit is a pipe which occurs at the actual contact of the granite and the overlying and silicified sediments. The workings are about 240 feet in length as measured along the dip, which is probablf less than lin 2. Several openings were made here in the early days, one a few yards below the present entrance and one a little to the right as the entrance is faced. From the outcrop and from the portion of the deposit near the surface, it is reported that the early workers found large patches of very rich bismuth ore. The pipe is somewhat irregular in size. In places it is from 5 to 6 feet in height and from 8 to 10 feet across. A large dyke has intersected the pipe at a considerable depth below the surface, and the earlier workers of the deposit abandoned it because of the trouble caused by the dyke intrusion. Mr. W. Turbet and party picked up the pipe beyond the dyke and followed it along the contact. Aid from the Prospecting Vote was granted to prospect the pipe, and the deposit is being prospected under this grant. At the deepest point reached in March, 1916, the pipe appeared as though it might be about to leave the contact zone, inasmuch as the slate roof appeared to be rising while the pipe appeared to be descending. This, however, may be merely a local feature. In my opinion this pipe is worthy of further prospecting. 2. The Whipstick Mines, Ltd. — The accompanying sketch plans and sections illustrate the general occurrence of the pipes, but there is no preten- sion to accuracy in the plates and figures, as they have been compiled merely from measurements and directions supplied by Messrs. Schafer and Robertson during my tour of inspection. The figures, however, are approximately correct, and they illustrate the relation of the pipes' to each other, as also to the granite and the altered sediments in the immediate vicinity. The deposits outcropped on a steep hillside, and as they were followed below the surface the workings were connected by means of tunnels driven into the hillside for several hundreds of feet from which crosscuts were made to the mine workings. Vertical measurements in the mine are referred generally to the main, or No. 1 Tunnel, thus the bottom workings are spoken of as being 260 feet below the No. 1 Tunnel, while the No. 2, or main, pipe is The Whipstick Mines. [Photo E F. Pittmaii.] Plate XXIII. 163 said to disappear at a height of 100 feet above the No. 1 Tunnel. The No. 2 Tunnel is also spoken of as 100 feet above No. 1. This tunnel was driven for a distance exceeding 400 feet in order to test a well-defined quartz reef which has a long and well-marked outcrop. This reef is said to have been proved by the tunnel, but no deposit of commercial value was found therein, and the reef has not been tested further at this depth. The bottom workings are in the main, or No. 2, pipe only, which is about 25 or 30 feet across in greatest measurement, the larger axis being almost north-east and south-west. The indications suggested by an examination of the workings about 25 feet higher up are that another pipe exists in the immediate vicinity. At a height of 35 to 40 feet above the bottom a drive to the north-east has been put in a large garnet pipe. The deposit is large, and is about 25 feet in longer diameter, while its shorter axis or diameter has not been proved as yet. The garnet is massive, granular, and reddish. It contains irregularly- shaped patches of quartz, with native bismuth, sulphide of bismuth, telluride of bismuth, and molybdenite. This pipe was not met in the upper workings, and it has been proved only through a height of about 7 feet. It is almost in contact with the main, or No. 2, pipe. The average content of bismuth and molybdenite in this great pipe is not known, but large rich bunches of ore are said to have been obtained there- from, and according to Mr. Schafer, the returns were so promising that great hopes are entertained of a large supply of milling ore from this part of the mine. According to Mr. Schafer also, the bottom of the No. 2 pipe was systematically sampled for bismuth, and the result was about 1 per cent, of this mineral. This was done years ago, and the molybdenite content was neglected. About 60 feet above the bottom workings, and 200 feet below the No. 1 tunnel, the main pipe in cross-section has maximum measurements of 25 and 15 feet, while the No. 3 pipe is about 7 feet in diameter. The workings are connected, and the longer axis of the pipes are almost collinear. About 50 feet below the No. 1 tunnel, and about 200 feet above the bottom, the pipes exposed present an appearance much different from that at any of the lower levels. The main pipe has axial measurements of about 12 and 15 feet in cross-section, but the longer axis is not collinear with that of the associated pipes. No. 3 pipe appears to be leaving the main deposit more and more. No. 1 pipe, from 8 to 10 feet in diameter, is in contact with the main deposit. No. 1 pipe does not appear to have been proved much below this level, and it is probable that it has branched from the main pipe near this level. Two other pipes occur to the south of the axis along which Nos. 1, 2, and 3 are arranged. These are the No. 4 and the Pilot. The Pilot consists of brittle white quartz surrounded with a narrow zone of garnet, while the No. 4 is of altered granite surrounded in places with a narrow zone of white mica. The latter has an erratic course and has not been found above the No. 1 tunnel. At the No. 1 tunnel level, the Nos. 1, 2, an(I 3 pipes have their longer cross axes arranged in a line or plane. The main, or No. 2, is large, but Nos. 1, 2 and 3 are relatively small. No. 3 is seen as diverging from No. 2. The No. 4 has disappeared, while the Pilot, with its enclosing zone of garnet, is still to the south of a line connecting the main axis of Nos. 1, 2, and 3. 164 The No. 2 tunnel is about 100 feet above No. 1 tunnel, and at a depth of a few feet below this level the longer axes of Nos. 1, 2, and 3 pipes are approxi- mately collinear along a plane almost N.N.W. and E.N.E. No. 2 pipe is large. No. 3 here is distant 50 to 60 feet from the No. 2, while the Pilot has moved apparently round No. 2. It is here small and in contact with No. 2. At and just above the No. 2 level a remarkable change is apparent in the arrangement and appearance of the pipes. The main, or No. 2, pipe has disappeared, except for the existence of a few patches of garnet and a narrow joint carrying much molybdenite. It is possible that this joint may lead in the direction of another deposit of bismuth and molybdenite at a higher level, but it must be admitted that the skilled and experienced prospectors of this field have been unable to trace the pipe in a vertical direction above the level. The Pilot also has been lost at this level. No. 1 is large and has diverged from the general direction of the No. 2, while No. 3 is also large and about 60 feet to the north-east of No. 2. Prospecting operations at this level have led to the discovery of several large pipes leading upwards and connected only indirectly with either the No. 1, No. 2, or No. 3 pipes. Two of these lying to the south of the No. 2 are especially large, the No. 5, or the south stopes, being fully 30 feet in diameter. The Jump Up, or what may be called No. 6, inadvertently shown on the accompanying map as No. 2, on the plan as F, is about 20 and 25 feet in axial measurements in cross-section, and it is traversed by two, if not three, parallel dykes. One of the dykes is kaolinised, and appears to be a decomposed felsite, while a dyke alongside is hard and of felspar-porphyry. These dykes appear to have intersected the pipe, as the body is cut quite cleanly, the walls being sharp with a dig or “ flucan.” Nos. 1 and 3 pipes outcrop on the hillside. Treatment Plant. — The ore is crushed in a battery and passed over three Wilfley tables. The bismuth is collected as a marketable product over the end of the table, the molybdenite and the sands being elevated to a conical settling pit and passing thence to a 12-inch Mineral Separation unit. This plant is described elsewhere (p. 10) in the report. As a guide to the recovery which may be expected to be made by the plant, the accompanying results of two trials by the Mineral Separation may be quoted from a return furnished by the Mineral Separation Company. Both samples were crushed to 60 mesh. Test I. Weight. Assay. Recovery. MoS 2 . Bi. Fe. Insol. MoS 2 . lb. % % % % % % Crude ore ... 1,906’ 100 5-2 0-4 0-9 90-2 100-0 Concentrates ... ... 105 5-5 87-0 3-0 0-7 9-4 91-0 Residues 88-6 0-2 1 ... 3-4 Eucalyptus, f lb. a ton of ore. 165 The concentrates were refloated with a little sulphuric acid added. The middlings cut out from the concentrates contained approximately 3 per cent, molybdenite and 2 per cent, bismuth. Test H. Weight. As«ay. Recovery. MoS 2 . | Bi. Fe. Insol. MoS 2 . lb. % % ! % 1 % O/ 1 O/ /o /o Crude ore 2,208 100*0 5*14 0*6 ! 0*7 100*0 Concentrates ... 117 5*3 87*7 1*4 | 0*4 9*5 90*4 Residues 93*3 0*3 1 ~ 0*4 8-4 Eucalyptus, £ lb. a ton of ore. The concentrate was refloated with a little sulphuric acid (J lb. acid a ton of ore). At the completion of the tests the concentrates w T ere bulked and refloated producing a final concentrate assaying 90*5 per cent, molybdenite, and 1*3 per cent, bismuth. In this operation about 2 per cent, of the total molyb- denite was left in the middling which would be re-treated in practice. According to Mr. Schafer, the loss in the actual treatment up to date is about 0-4 unit molybdenite. This indicates the advisability of handpicking the ore to 4 per cent, molybdenite before treatment. Future of the Mine. — In the earlier days of mining at Whipstick the molyb- denite was rejected as an impurity in the bismuth ore. Moreover, owing to the primitive methods employed in the treatment of the bismuth ore, a considerable amount of the bismuth was not recovered also. This unrecovered material, in some measure, lies about the hillside near the mine workings. During the years 1914 and 1915 a very large tonnage of this material was hand-picked and sent both to Sydney and elsewhere for treatment. A great amount, however, still exists on the hillsides and in the base of the small gully along which the surface mining workings have been carried out. Thus the plat at No. 1 Tunnel is triangular in plan, its apex pointing to the tunnel mouth and lying about 10 feet in front of same, and there ending abruptly against bed-rock in the steep gully bed. The distance from the apex to the centre of the base of the triangle is about 70 feet, and the length of the base is about 70 feet. This triangle base forms the edge of the plat, which slopes steeply thence to the gully base 45 feet vertically below. This heap contains from 1,750 to 2,000 tons of low grade ore necessitating hand-picking before its despatch to the mill, 1 J miles away. According to Mr. H. Robert- son, about one-half of the material composing these heaps is to be sent to the mill, but it is not possible, without experience, to estimate the average grade of this hand-picked material. Both on the plat, and below it, are large heaps totalling between 300 and 400 tons of low grade bismuth and molybdenite ore. | On the hillsides between No. 1 Tunnel mouth and the outcrop of No. 3 pipe about 200 feet vertically above other large deposits of low grade molyb- denite lie scattered about, and the tonnage in these must be somewhat comparable with that in the large heap forming the plat at No. 1 Tunnel. 166 In the mine itself molybdenite ore occurs in the No. 3 pipe, about 40 feet below the surface. There is a large body of ore exposed in the main, or No. 2 pipe and the Garnet Pipe at the lowest levels worked as yet in the mine. Other ore patches of variable size occur in different parts of the mine such as the “ Jump Up,” the No. 3, and from a point below the No. 1 tunnel. From the two firstmentioned of these^ places the magnificent ore specimens were, obtained which were sent to the Panama Exhibition and a fine sample of which is on view at the Departmental Museum at Miller’s Point. In my opinion the Whipstick Mines are worthy of a vigorous policy of development and prospecting. 3. Young and Reid. — The leases held by these partners in 1915 consisted of M.L. 30 of 8 acres, and M.L. 33 of 10 acres, approximately. The workings in these leases are numerous. Some are old while others are recent. They all occur in the granite near the old sedimentary roof. Most of them are shallow and show the usual favourable indications of manganese and mica gossans. Certain of the deposits appear to be arranged linearly, while others suggest a tendency to branch. Wilson’s Downfall Deposits. 1. Flint's Molybdenite Vein . — Described by Mr. E. C. Saint-Smith in 1909 as “ 3 chains south of the Maryland to Wilson’s Downfall Road, on left bank of Tompkins’ Gully, Parish Ruby, County Buffer, 10 miles north-west of Wilson’s Downfall. Discovered by Thomas Flint about 1910. Only a few pieces of rock have been broken by fossickers. The molybdenite occurs as scattered small flakes in a coarse siliceous granite intruded by a small aplite vein with a strike of north 10 deg. east.” 2. Fordham's Molybdenite Vein . — According to Mr. E. C. Saint-Smith the occurrence under consideration was noted in the “ bed of Two Mile Creek, 2 miles south of Wilson’s Downfall, Parish Corry, County Buffer.” According to the same authority it was “ discovered by Lewis Fordham about 1904, but no work was done. Strike N. 25 deg. E., and a dip apparently vertical. The molybdenite occurs very sparsely as fine blebs and scales in a, narrow white quartz vein, 12 inches wide, traversing unaltered hard coarse biotite granite. Traced for a few feet in length. A similar vein, parallel to- this one, occurs 10 feet away. “ This occurrence would seem to be worthless from a commercial point of view.” 3. Gunn's Authority . — Portion 54, Parish Ruby, County Buffer. Apparently molybdenite flakes in sandy granite. Information supplied by Mr. Warden Perry. Hughes' Wolfram Lode . — Mr. J. E. Carne described this deposit as being “ on the west side of the Wilson’s Downfall-Stanthorpe Road, near Amosfield, 1 mile north-west of Wilson’s Downfall, Parish Ruby, County Buffer. “ Discovered about 1898, worked mainly by Rees Hughes in 1907-8 for about eight months, who opened it by a trench 40 feet long, and 9 feet at deepest. “ Examined in 1910 by E. C. Saint Smith, who described the wolfram as occurring in a bluish- white quartz vein, varying from 8 to 15 inches in width, which splits and reunites from point to point, small lenticular ‘ horses ’ of Tungsten Mining Industry. Mineral Resources, 15, 1911, p. 59. 167 aplite being enclosed by the quartz. Wolfram occurs in patches, prin- cipally in the central portion of the vein. It is associated with a little iron and copper pyrites, metallic bismuth, bismuth-carbonate, and flakes of molybdenite. “ Thin veins of quartz extend from the main vein into the aplite. The quartz is crystallised in part. The lode traverses aplite for the most part, but where it passes through coarse granite it is bordered by micaceous granite. The lode has been opened by small potholes for a length of about 600 feet. “ The molybdenite does not appear to occur in commercial quantity.” 4. Martin's Authority to Enter. — Portions 72 and 73, Parish Ruby, County Puller. Molybdenite flakes in sandy granite. Information supplied by Mr. Warden Perry. 4a. Maryland. See Waterson’s (John) Claim. 5. Staine’s Lease. — P.M.L. 1, of 5 acres, within Portion 72, and an Authority to Enter of about 5 acres, adjacent to P.M.L. 1 on the west, within Portion 68, Parish Ruby, County Buller, at Maryland, and about 8 miles north- north-east of Wilson’s Downfall. Molybdenite occurs as fairly large flakes and crystals in a coarse siliceous granite near its junction with a granite of very siliceous nature. Upon casual inspection the molybdenite appears to be scattered at random through- out an unaltered granite, but upon closer inspection it may be seen to be associated, in places, with very small flakes of secondary mica along tiny joints, as also at the intersection of these joints. Quartz is also associated with the molybdenite. Alongside certain of these joints the granite is discoloured for widths varying from 1 to 10 inches, and this discolouration appears to be due to an oxidation of iron which had been introduced, probably as iron pyrites, into the granite along the joints which favoured the passage of the molybdenite and silica vapours. Fig. 1 illustrates a detail of this occurrence seen on the outcrop alongside the open cut. It suggests an early stage in the formation of a “ granite ” pipe (see p. 28). The workings occur in the northern portion of P.M.L. 1, and they consist of an open cut about 40 feet in length and 15 feet deep at one point. The prospects are not encouraging, from a commercial point of view, as there appears to be very little hope of expecting the tiny intersecting joints to form a pipe lower down. 6. Stalling's Lease. — M.L. 2, of 8 acres, on Crown Lease, Parish Wylie, County Buller, alongside main road from Stanthorpe to Wilson’s Downfall, and about 1 mile from Wilson’s Downfall. According to the statement of of the prospector, Mr. H. J. Stalling, molybdenite in small veins of quartz has been found in the lease traversing a sandy and cavernous granite of line texture near its intrusive contact with a coarse hornblende granite. Wolfram occurs also in the lease, but is not associated directly with the molybdenite. Mr. Stalling stated that one shaft was about 40 feet deep in September, 1915, and that other prospecting work had been done also. The veins appear to be narrow, six in number within a belt of country rock about 50 yards in width. The strike of the deposits is said to be parallel to the longer sides of the lease, that is about north-east and south-west, and the veins are said to persist throughout the length of the lease. The molybdenite is said to occur as large flakes in brittle, white, and cavernous quartz. 7. Sugarloaj Mountain. — Parish Ruby, County Buller, on the New South Wales-Queensland border, about 12 miles west of Wilson’s Downfall village. 168 The mountain is rugged and rises about 3,700 feet above sea level, and about 600 feet above the Wilson’s Downfall Plateau. Mr. E. C. Saint-Smith reports* that “ the summit of the Sugarloaf Moun- tain is composed of a coarse-grained granite Several veins of greisen occur through the rock mass, especially at the head of Herding Yard Creek and its tributaries on the Queensland border. These veins as a rule carry tinstone, wolfram, and a little molybdenite, with occasional coatings of iron and copper pyrites along joint faces.” Sugarloaf Claim. — M.L. 50, about 20 acres approximately, Parish Ruby, County Buller, at Sugar Loaf Mountain. In the north-eastern portion of the lease a great number of loose fragments of impure quartz were seen. These contain flakes of molybdenite and appear to have been shed from a vein. In the western portion of the lease a small quartz vein outcrops with a strike approximately north 40 degrees east, and a dip almost vertical towards the south-east. The vein has been proved for 70 yards at least within the lease, and it has been traced for a considerable distance within the State of Queensland to the west. The vein traverses granite of fine texture and very siliceous nature near its intrusive contact with a basic granite containing much hornblende. The minerals found in the vein include wolfram and scattered flakes of molybdenite. The deposit was prospected many years ago for wolfram by means of shallow shafts and open cuts, the depths of which vary from 5 to 25 feet approximately. In one of these open cuts, now partly filled with waste, and about 15 feet in depth at the present time, the vein may be seen to be split into two, each about 4 inches wide near the surface, and forming one vein about 8 or 9 inches in width at a depth of 12 or 15 feet. The wolfram in the vein is in the form of plates, and is of good quality. The molybdenite occurs as scattered flakes of small size in the silicified granite alongside the quartz vein. Fig. 28 illustrates the approximate position of the vein in the lease. Mr. R. F. H. Ormiston has a lease of the area at the present time, and he states his intention of working the quartz vein for both wolfram and molyb- denite. The prospects for wolfram are certainly encouraging. This vein may be the same as that described as Stalling’s Lode, by Mr. J. E. Carne, which was discovered by G. and F. Stalling in 1892, but not worked until 1907, and in which wolfram, with a little molybdenite, was reported to occur. 9. Waterson’s {John) Claim, Maryland. — This has been worked by means of a Mineral Prospecting Area of 40 acres, near Portions 78 and 79, on Crown land, and held as a special lease by W. Waterson, in Parish Ruby, County Buller, at Maryland, about 8 miles to the north-north- west of Wilson’s Downfall. The occurrence is of the nature of a granite and pegmatite “ pipe ” about 9 or 10 feet in diameter, within a coarse siliceous granite. The pegmatitic granite composing the “ pipe ” is variable in appearance, and may consist of : — (a) Large long crystals of orthoclase felspar in a glassy paste of bluish and translucent quartz. ( b ) Irregular patches of an intimate mixture of quartz and felspar grains in a paste of translucent bluish and glassy quartz. * J. E. Carne. Tin Mining Industry. Mineral Resources, 14, 1911, p. 84. •The Tungsten Mining Industry. Mineral Resources, No. 15, 1911, p. 67. 169 The pipe, so far as proved, is vertical, but the greatest depth reached appears to be only about 20 feet. The shaft was half filled with muddy water during my visit in September, 1915, thus the lower portion of the workings could not be examined at that time. From the nature of the specimens lying about the surface, and the general appearance of the pipe near the sur- face, however, it would appear that the deposit is worthy of further pro- specting. Rich speci- mens have been ob- tained in the pegmatitic mate rial usually as large, but thin flakes. 10. Waterson’s (J . F.) Claim . — Two Author- ities to Enter on W. Stonebridge’s C.P., Por- tions 58 and 59, Parish Ruby, County Buller, about 3J miles north of Amosfield. According to Mr. J. F. Waterson, molybdenite occurs here with wolfram in a small quartz reef in granite, north-east and south-west. Parish of Ruby, County of Buller. Occurrence of Molybdenite with Wolfram at Sugarloaf Mountain, Wilson’s Downfall. The strike of the reef is approximately 10. In a cutting along main road from Wilson’s Downfall to Stanthorpe. j mile from first-named township. — Occurrence : — Asa great number of scales and small flakes of molybdenite scattered throughout a miarolitic eurite dyke, The dyke is about 100 yards wide, and has its mica (biotite) in irregularly scattered plates (similar to mica in graphic granite). The association of the molybdenite with the peculiar miaroles shows it to be part of the intruding body which has cooled out in isolated patches, the hydration not .being pronounced enough to allow of the concentration of the mineral in quartz veins. The “ sandstone ” granite containing this molybdenite deposit intrudes the coarse porphyritic granite of Wilson’s Downfall. This latter is a unique rock type, and contains innumerable patches of tin greisen, also wolfram. The later “ sandstone ” granite occurs as bosses from 2 to 3 miles in diameter, with networks of dykes radiating therefrom. Wolfram Blow. See Kingsgate. Woomargama Station. See Holbrook (in Appendix). Woy Woy Creek. See Nambucca. Wunglebung. See Rocky River. Wymah. Yarrahappini Mountain. See Nambucca. 170 Yarras. “ About 4 miles westerly from the copper lode, on the Forbes River, a reel carrying fair bunches of molybdenite on the surface has been opened recently, but as only a limited amount of work has been done no opinion can be formed of the prospects.” [Extract from Prospector' s Guide, N.S. Wales, p. 82.] Yarrow Creek. See Kingsgate. Yates (W. H.). See Kingsgate. Yetholme District. The examination of the Yetholme molybdenite deposits was commenced in June, 1915, by Mr. J. E. Came, Government Geologist, and the Writer, several days being spent on the Mount Tennyson or northern portion of the field. In November the Writer spent several days at these deposits and the neighbouring ones of Gemalla and Tarana, while in January, 1916, he revisited the area for a couple of days with Professor H. E. Gregory, of Yale Sralo? ' Z ‘ * ^ Miles Plan showing the position of the Yetholme and Eusdale Molybdenite deposits. University, New Haven, U.S.A. A preliminary report was prepared jointly by Messrs. Carne and Andrews. This earlier note has been printed in the Government Geologist’s report for 1915.* Situation and communication. — The more important of the molybdenite deposits occur in the eastern portion of Parish Yetholme (Fig. 29), and the less known Gemalla deposits occur a few miles to the east, that is, in the western portion of Parish Eusdale, County Roxburgh. With these may be included the Tarana deposits hung a couple of miles farther east, also in Parish Eusdale. Both the Yetholme deposits proper, or Mount Tennyson, Annual Report, 1915, p. 170-177. Plate XXIV. [ Photo J . H. Fawcett ] (a) Mount Tennyson and the Macquarie Valley. The valley is about 1,400 feet deep. The knob shown just beyond Garrard’s house is a garnet outcrop. [Photo J. If. Fawcett ] (b) Mount Tennyson from Wambool. The garnet rock extends from 0 to 0, and still further to the east. 171 and the Gemalla deposits lie near the Great Western Railway line, the former about 2 miles northerly of Locksley, the latter 2 miles northerly of Gemalla railway station. The Tarana deposits lie about 3 miles northerly from Tarana railway station. Tarana, Gemalla, and Locksley stations are distant from Sydney by rail, 120, 125, and 129 miles, respectively, and are respectively about 2,563, 2,538, and 2,500 feet above sea level, while the highest points of the molybdenite workings at Tarana, Gemalla, and Yetholme respectively are about 3,100, 3,800, and 3,800 feet above sea-level, respectively. No direct road connects the Yetholme and Gemalla deposits with the railway stations, and in the case of the Mount Tennyson or Yetholme deposits proper, all passenger and goods traffic at present is with Wambool railway station, 131 miles from Sydney, and 2,600 feet above sea-level. A steep road with good surface and about 8 miles in length connects Wambool with Yetholme, 3,600 feet above sea-level, approximately, thence communication is secured with the Mount Tennyson deposits by bush road about 5 miles in length. A considerable amount of money would be needed to secure a good connection by road with these deposits either from Yetholme or Locksley, inasmuch as most of the deposits outcrop on the sides of deep and steep ravines. (PI. XXIV.) Similar remarks apply to the case of any proposed connection by road with the higher deposits at Gemalla. Geography . — The district is drained by the Fish River, one of the two main tributaries of the important Macquarie River. The Fish River is distant only 2 or 3 miles in a straight line from the Yetholme deposits, but whereas the stream is only about 2,450 feet above sea-level at Tarana, the upper deposits of Mount Tennyson, as near Garrard’s House, are about 3,800 feet above that level. The appearance of the wide and deep Macquarie valley, from Mount Tennyson itself, is such as to suggest that the Macquarie River carved its own valley out of the plateau. This was not the result of a simple operation but of one which has been repeated or renewed at various times, because traces of old valley floors are to be seen at levels much higher than the present river level. Thus there appears to be a general north-westerly pitch to the main plateau surface of the region. Yetholme, Blayney, and Orange lie on this dissected level while high residuals of former land masses rise above this general surface. Examples of such residuals are the Tarana, Yetholme, Sunny Corner, and other Trigonometrical Stations, as also large sub -horizontal masses as Sunny Corner hills themselves. Through tins general plateau surface the Macquarie appears to have cut a shallow but very broad valley, many miles indeed in width. Remnants of this floor are to be seen around Brewongle, Wambool, Mount Pleasant, and other places, and lying from 2,600 to 2,800 feet above sea-level. Below this broken surface the river has excavated other broad and shallow valley-in- valley structures, the whole appearance being strongly suggestive of a former surface of low relief, which had been raised in the past, thus enabling the Macquarie streams to excavate a broad and shallow valley in the low plateau. During periods still later the land rose again giving increased cutting power to the streams; thus the main broad valley now has the appearance of valley-in- valley structures. The valley proper of the Macquarie has been excavated within dense granite structures, nevertheless, these are weak as compared with the associated Devonian, Silurian, and other Palaeozoic structures of Sunny Corner, Yetholme, Tarana, Orange, and Oberon. Thus, while the main Macquarie has worn the granite of the Bathuist district down to broad 172 undulating forms the side streams have excavated gorges only in the dense Palaeozoic structures of the higher plateaus. So marked is this difference in strength between granite and altered sediments, associated with the granite, that near Tarana the river flows within the granite, and is overlooked by sediments forming dissected escarpments rising from 1,000 to 1.200 feet above the river, and having an alignment such as to suggest a fault-origin for the valley at this point. This alignment of spur points at one time led the Writer to a belief in the origin of the Macquarie valley by the action of faulting,* but an examination of the Cargo Gold Field and the Yetholme molybdenite deposits has led him to the belief in the origin of the great valley by the action of running water. Sketch section across altered sediments near north-west corner P.M.L. 5, Parish of Yetholme, County of Roxburgh. A — Quartz porphyry. B — Silicified porphyry (?), containing hornblende, garnet aggregates and wollastonite. C — Granular garnet rock containing amphibolite, silicified sediments, small quartz aggregates and molybdenite. Maximum thickness from 20 to 35 feet. D — Mass of limestone with claystone altered to granular marble, wollastonite and garnet with silicified claystones. E — Large masses of altered marble. Geology . — The geology of the Yetholme field is highly interesting, and is well worthy of detailed study by a research student. The accompanying notes are merely of reconnaissance nature, and are based upon field notes made during a couple of visits extending over about eight days all told. The accompanying map, sections, plates, and sketch figures will help to make the descriptions clear. General Geology . — The Yetholme and Gemalla molybdenite deposits fall under the head of contact deposits. A large mass or bathylith of granite has intruded the older Palaeozoic sediments of the Bathurst district. The granite characteristically forms the lower portions of the landscape, while the altered and folded sediments associated with the granite, and intruded by the same, stand out as high and deeply-dissected surfaces. This is only true in the main, for the bathylith is of the composite type, being of basic nature for the greater part, but containing large masses of very siliceous granite in the eastern and southern portions. These siliceous types stand up as high residuals of the lower land surface cut in the basic granites or they * The Geographical Unitv of Eastern Australia in Tertiary and Post-Tertiary Time. Procs. Roy Soc. N.S. Wales, vol. XLIV, 191*0. 173 form portion of the higher plateaus as at Tarana Mountain or Yetholme village. The bathylith extends east and west from a point near Rydal to a point about 15 miles west of Bathurst, a distance exceeding 40 miles, while it has a great development both north and south of Bathurst. The late Mr. W. J. Clunies Ross suggested that future workers might establish a laccolithic origin for the bathylith.* The more northern, central, and western portions of the mass are of basic nature and good crops of wheat and other produce have been obtained from this type for the past sixty years. It is the rock mass underlying the “ Bathurst Plains.” In the neighbourhood of Yetholme and Gemalla the siliceous granites appear to have intruded the basic granite near its intrusive contact with the older Palaeozoic sediments. To the immediate north of Yetholme the siliceous granite is aplitic in appearance in places, in others porphyritie, fine in texture, and miarolitic. In these types scattered flakes of molybdenite occur as an acces- sory constituent. Still farther north the granite is coarse and more basic and contains small quartz veins with flakes of molybdenite, as in Donaldson’s paddock. Under Mount Tenny- son, or the Yetholme molyb- denite field proper, the granite is coarse and siliceous, but between it and the intruded sediments, in patches, there exists a marginal development of considerable width of a granite of varying texture and composition. In places it has the appearance of a siliceous pegmatite; in others it appears as an aplite, while in other places it merges into a granite of fine texture containing small crystals of ferro -magnesian minerals. The contact zone is wide, long, and narrow, extending for several miles along the granite margin, and extending about 1 mile into the sedimentary rocks at the most. The zone of alteration may reach about 200 feet in thickness as a maximum, while that portion of the alteration zone which contains the molybdenite has not been proved to exceed 30 feet in thickness, excepting in one spot. Fig. 31. Sketch section across garnet rock near south- western corner of P.M.L. 5, Parish of Yetholme, County of Roxburgh. A — Granular garnet with blebs and patches of glassy quart/, containing flakes of molybdenite. B — Large blocks of sediment altered by introduction of silica, lime, and iron. C — Large and small patches of ladiating wollastonite, generally spheroidal. D — Mass of segregations of wollastonite with cement of granular garnet. The sediments intruded are older Palaeozoic limestones, claystones, sand- stones with quartz porphyry masses apparently as interbedded flows. The vegetation of the quartz-porphyry is peculiar, consisting of stunted growths of Eucalyptus Cambagei (Bundy), E. dives (Peppermint), E. maculosa (White Persona] communication in 1894. 174 Gum), Brachylome daphnoides, and dense growths of Stypandva glauca y and Boa ccespitosa. The limestones occur as small lenses, and have been changed to sugary marble. The beds associated with the limestones are of fine texture, and they occur in very numerous and very thin beds. They have all been intensely silicified, and in places appear as quartzite, or flinty claystone. They may be altered claystone beds or volcanic ash. There is probably a considerable calcareous content in their composition. They are distinguished particularly by a development of luxuriant growths of Casuarina stricta, or long-leaved oak. The molybdenite occurs mainly in a garnet zone, and this, in the northern portion of the field, appears to overlie the so-called claystone, or volcanic ash, beds and the altered limestone lenses while it is in turn overlain by the quartz-porphyry and ash beds. On the southern portion, however, of Mount Tennyson in the vicinity of Kirk and Wade’s blocks, the garnet zone is both overlain and underlain by the so-called claystone beds, the limestone being .2 :o" Fig. 32. Detail of alteration in P.M.L. 10, Parish of Yetholme, County of Roxburgh, A — Silicified sediments. B— Alteration of sediments to siliceous material , contain - ing garnet, hornblende, and other minerals. Fig. 33. Sketch section of rock structure in P.M.L. 1 5, Parish of Yetholme. A — Granular mass of garnet, with quartz and traces of molybdenite. B — Bedded claystones (?), altered to silice- ous masses, with wollastonite and garnet segregations and amphibolite. absent, and the quartz-porphyry and ash beds being above the zone of alteration. In Parish Gemalla the garnet rock is pronounced but relatively thin, the zone of alteration is not thick, and the overlying and underlying beds are different from those of Mount Tennyson. At Borchardt’s claim, on Tarana Mountain, the siliceous granite is associated with a sill about 25 feet thick of fine-grained granite (Fig. 42). A zone of alteration, somewhat similar to that at Yetholme occurs on each side of the sill. In this case the underlying rocks appear to have been claystone altered to quartzites, and the overlying rocks appear to be fine volcanic ash or sandstone. No limestone was obeerved in situ. The garnet rock, therefore, does not appear to have been developed between any two particular layers of sediment or rock, except locally. The garnet zone may occupy the central portion of the belt of alteration ; or the alteration may occur either above or below the garnet layer in the main. These points are illustrated in the accompanying coloured plan and sections. This garnet zone, again, is of variable width. In some portions of P.M.L. 15, it has been seen about 25 feet in thickness, whereas in others it has been seen EPOSITS IE) Outcrop of 'arnet — molybdenite rock on plateau near the main road to Vet holme _ $ 500 ' 5000 ' containing epidote, fuartz and molybdenite Palaeozoic sediments, claystone (?) volcanic osh (?) and limestone. ■IOTO-LITHOQRATHED BV W. GULLICK, GOVt. PRINTER. N.S.W. SKETCH GEOLOGICAL PLAN OF THE MOLYBDENITE DEPOSITS AT i MOUNT TENNYSON (YETHOLME) PARISH OF YETHOLME 175 no thicker than 2 feet; and again in P.M.L. 15 it has been observed to die away altogether over small areas (Figs. 33, 34 and Map). The garnet belt contains the molybdenite, amphibole, epidote, calcite, and quartz in various forms, generally as small lenses, eyes, streaks, tiny veins and small patches of irregular shape. In the region of the granite and the limestone patches the zones of alteration, or zones of transition between the garnet-molybdenite layer and the unaltered sediments are of considerable thickness, but at considerable distances from the granite, limestone being absent also, the zone of alteration or transition is not thick. This zone of alteration has an interesting ipineral composition. In the northern end of the field, as in Kirk’s and in Field and Garrard’s blocks, lime- stone patches outcrop within the zone, and these may be seen to be traversed by networks and knots of granular garnet of a brown to honey colour. (Fig. 36.) Large spheroidal masses of wollastonite also occur in the altered limestone (Figs. 34, 37, 38). Surrounding these limestone masses beneath the garnet layer are considerable thicknesses of altered sediments of fine texture. These, for very many feet vertically, have been intensely sili cified, while in many places they have been altered in other directions. This more intense alteration is of a patchy nature, taking the form of huge pockets beneath the garnet zone (Fig. 39). In these pockets the [Figs. 31, 34, 38, 44, and 45] alteration products consist of spheroids of cherty or flinty material, veins and patches of impure quartz, spheroids of granular marble, spheroids large and small, of wollastonite, and strings, kernels, knots and patches of granular garnet. Patches of calcite with crystallised garnet are also common, one rhom- bohedron of the latter mineral exceeding 2 inches in diameter. Above the garnet zone in the northern portion of the Mount Tennyson area, the altera- tion belt is banded, the bands being parallel both to the general plane of the garnet-molybdenitee zon and to the dip of the beds generally (Figs. 35 and 36). These altered and overlying rocks are mainly quartz- porphyry types, and the parallel zones or belts traceable in them consist in the main of wollastonite masses. These are mainly spheroidal or ellipsoidal in shape, and they may, or may not, possess kernels of sugary or granular marble. Figures 34, 37, and 45, illustrating this feature, are sketch sections of such forms from measurements bv Professor H. E. Gregory and the Writer. These wollastonite masses with marble kernels may occur either above or below the garnet- molybdenite zone, and they cannot be shown to have been derived directly from the limestones of the vicinity. In the southern portion of the field, as in Kirk and Wade’s blocks, and at Borchardt’s lease on Mount Tarana, there are numerous spheroidal or ellipsoidal masses of wollastonite, some with kernels of marble (Figs. 37 and 45), which occur in large pockets of alteration (Figs. 36 and 39) in sediments which appear to be altered claystone or volcanic ash- beds of very fine texture. It would appear, as a result of this very incomplete examination, that a composite bathylith had intruded the older Palaeozoic sediments of the Bathurst district in post-Devonian and pre-Permo-Carboniferous time, that the portions intruded first were basic granites and allied types, and that these were intruded in turn in the Yetholme area by very siliceous granitic rocks of variable texture and mineral composition, and that these siliceous types were arranged marginally to the great mass of the granite intrusion proper. Vapours containing molybdenum, sulphur, iron, abundant silica, as well as other elements, appear to have been expelled from these siliceous. 176 granite types into certain zones of relative weakness in the associated and intruded palaeozoic sediments. The zones, along which the vapours could advance with relative ease, were the bedding planes of the sediments and and lavas, the forms assumed by the action of the vapours are very similar to those of sills, in that they conform to the bedding pianes'in the main, but transgress them in places, thus passing, in places, from one set of bedding planes to another. Fig. 35. Sketch section near south-west cor- ner P.M.L. 15, Parish of Yetholme. A — Fine-grained sediments altered to greenish mass of wollastonite, silica, hornblende and garnet. B — Compact brown mass of granular garnet, with small patches of quartz and traces of molybde- nite. B — Silicified porphyry, containing amphibolite and wollastonite, with some garnet (the so-called diorite of the miners). C — Silicified rock, containing a low percentage of molybdenite. D — Mass of altered claystones and limestone. E — Altered limestone bed. F — Silicified fragment (15 feet long) of claystone. G — Granular marble invaded by strings, and aggre- gates of garnet. H — Large aggregates of wollastonite in po*t