DESCRIPTIVE CATALOGUE OF THE SPECIMENS OF THE ROCKS OP VICTORIA IN THE Industrial ant) ^ethncrlcrgkal MELBOURNE. GEOLOGY OF VICTORIA. DESCRIPTIVE CATALOGUE OF THE SPECIMENS IN THE Industrial mtb ^tthnalxrgical (MELBOURNE), ILLUSTRATING THE EOCK SYSTEM OF YICTOKIA. GEORGE H. F. ULRICH, M.E., F.G.S., Lecturer on Mining at the University of Melbourne, and Curator of the Mineral Collection in the Industrial and Technological Museum, Melbourne. MASON, FIRTH & M'CUTCHEON, GENERAL PRINTERS, 51 & 53 FLINDERS LANE WEST. 1875. PUBLIC LIBRARY, MUSEUMS, & NATIONAL GALLERY OF VICTORIA. Incorporated by Act 33 Vic., No. ccclvii. His Honour SIR REDMOND BARRY, President. DAVID CHARTBRIS M'ARTHUR, Esq., Vice-Pre- sident. Hon. J. A. MAcPiiERSON, M.L.A., Treasurer. The Hon. SIR WILLIAM F. STAWKLL, Chief Justice. Hon. SIR FRANCIS MURPHY, M.L.C. His Honour Sir. JUSTICE FELLOWS. Hon. SIR Jons O'SHANASSY. Hon. SmC. GAVAN DUFFY, M.L.A. Hon. SIR JAMBS M'CuLLOCH,K.C.M.G., M.L.A. Hon. JAMES GOODALL FRANCIS. Hon. THOS. TURNER A'BBCKBTT, M.L.C. Hon. SAMUEL HENRY BINDON. CHARLBS E. BRIGHT, Esq. Rev. JOHN I. BLEASPALE, D.D. Hon. SIR WILLIAM H. F. MITCHBLL, M.L.C. M. H. IRVING, Esq., M.A. SIR GEORGE VBRDON, K.C.M.G., C.B. Hon. CHARLBS MACMAHON, M.L.A. Hon. WILLIAM M. K. VALE. Hon. F. S. DOBSON, L.L.D., M.L.C. Hon. JOHN MACGRBGOR. Hon. EDWARD LANGTON, M.L.A. INDUSTRIAL & TECHNOLOGICAL MUSEUM, LABORATORIES, &c. W A Q 55 il _o'E ife 1 1 ^H S 5 a . fa j~ 0,g || 1 ' ' si d 1 1 1 1 o5 ^5 Plagioclase Roc! With Augite without Quartz). la 1 . iabase-Porphyry, ^.ugite-Porpbyry, >radorite-Porphyry. Dolerite, Anamesite, Feldspar-Basalt. Tachylite. j K$ " Ca ith Hornblende ith and without Quartz). oT ^ w .2*^ O J o^ orite-Porphyry, blende-Porphyrite, aclase-Porphyrite. P Andesite. .. ^ j "^ Og.Bf o M O TO i _ g o- - s-fc- > >- III 03^ i 'o B o CM |s ?fl if H 1 i s o 3 0) s|3 a 3|.o 'g ^'^ CU Qaartzless Orthoclase- Porphyry. i f. A o i m 09 ^ J3 ^ *J -^ ^ o N 1 g o SB 3 cc'o "I 1 ^i. ^^ *- t- r j ~~t A* s S ' ^ 3 g^' 3 J .2 13 "^^ ^ 3|g | "3 1 . a o E X 88 10 -^qdlo d . Xq , , 5 M ' JB I nnAU O jjtqdJoj jIBq pun pnn PUT! 1 omnBqdv 9n -oJd?o J &5S I9 1 ^P,0 I. CRYSTALLINE-GRANULAR SILICATE ROCKS. I. FELDSPAR ROCKS. A. OLDER FELDSPAR ROCKS; OLDER IGNEOUS OR PLUTONIC ROCKS. 1. ROCKS IN WHICH THE PREDOMINATING FELDSPAR IS " ORTHOCLASE." a. QUARTZOSE ORTHOCLASE ROCKS. THE species of rocks of this subdivision represented in the collection are granite (and syenite-granite); granite porphyry (and syenite-granite porphyry), and felsite porphyry. Of these the first and last are the most important, the intermediate species occurring generally only as local modifications, without any defined boundaries within tracts of granite. Granite This rock occupies a considerable portion of the area of the colony, forming larger and smaller isolated tracts and mas- sives, arranged without any system or without following any defined axis a mode of distribution which, according to Mr. Selwyn, seems to indicate the probability of the existence of the rock at no great depth beneath the entire surface of Victoria. Considering their physical features, the granite tracts exhibit each generally one or more high culminating points or massive ridges, from which descend steep rocky spurs, which in their turn gradu- ally merge into low swelling ridges, with here and there higher rounded bosses, and with broad grassy flats between. The higher points and spurs are in most cases quite bare, or support but a poor forest-growth of gum-tree (Eucalyptus), and, as specially characteristic, of she-oak (Casuarina) and honeysuckle (Banksia), which in most of the northern tracts is not even much improved in the lower country at foot, whilst in some of the southern ones (Gippsland) fine timber with dense undergrowth are there prevalent. Wherever the low swelling ridges or the higher rounded bosses are bare of vegetation, and show vertical sections, we observe the peculiar concentric-tabular jointing a special characteristic of B 2 4 granitic rocks. And isolated blocks of a more fine-grained texture than the rest, or two and three resting one upon the other often in fanciful shapes along the slopes or on the summits of the eminences, prove, by the gentle curvature of their top and resting- planes, to be the less destructible remains of as many concentric- tabular layers, long since disintegrated and removed. The boundaries of the granite areas, i.e., their junctions with sedi- mentary rocks (principally silurian), are partly very irregular, on account of numberless bends and ramifications, partly singularly well defined, often in straight unbroken lines for long distances (Mount Alexander granite, near Elphinstone, &c.). The influ- ence of the granite upon the bounding rocks will be noticed further on. With few exceptions, all the varieties of granite known and described occur in Victoria, and are represented in the collection, in all variations of texture, colour, and mode of composition. In the descriptions following and those given on the labels distinction has been made into binary, ternary, and quaternary granite, which qualifications refer to the number of the essential mineral components of the rock, i.e., whether it contains 2, 3, or 4. For instance, a compound of quartz, feldspar (orthodase and oligoclase}, and mica constituting the typical granite is called common ternary, whilst a replacement of one of these constituents by another mineral, for instance hornblende, tour- maline, talc, epidote, &c., is simply called ternary, and the modification mentioned. If a fourth mineral occurs in the rock, and by its mode of distribution or of association with the other three constituents appears as an essential component, the rock is called quaternary, and the new mineral noticed. It is generally one of the four just mentioned. In the reverse case of one of the three essential components being absent, the rock is called binary, yet with a certain reservation, namely, regarding the binary compound of feldspar (orthoclase and oligoclase) and mica in granular mixture, it is considered nearer allied to syenite, and called mica-syenite, in contradistinction to the typical horn- blende-syenite ; whilst, if the mixture is porphyritic, i.e., repre- sents a feldspathic base, enclosing ciystals of orthoclase and mica, it is called after the French minette, being in reality a mica- orthoclase porphyry. Amongst the specimens representing the binary granites in the collection is placed, however, a rather rare one, called greisen, a granular grey rock, composed of light-grey quartz and greyish, yellowish, and greenish mica ; the former in coarse grains strongly predominating. Although the absence of feldspar in this rock renders it inconsistent with the system of classification adopted to place it here, still as it stands in intimate relation to granite, it can be regarded as a granite variety without feldspar. In fact granite graduates into greisen, by a gradual decrease of the feldspar, the intermediate stages of which trans- formation may be considered either as granite poor in feldspar, or as greisen, containing as it were feldspar as an accessory constituent. It is an interesting fact that a very frequent acces- sory mineral of greisen in Europe, viz., cassiterite (tin-ore), in small crystals and grains, has here (Beechworth) also been found in it, and that the rock-mass from which the specimen in the collection was broken, occurs similarly as there associated with the variety of granite called tin-granite, which is also represented in the collection.* Granite has, in this colony, not as yet been much used as a building stone, owing principally to its being expensive to work on account of its hardness. The variety most abundant throughout Victoria, especially the western gold- fields a medium grained rock, composed of white feldspar, greyish-white quartz, and black mica though not of a very ornamental appearance, forms nevertheless a fine durable building stone, and could be procured at many places in large solid blocks. At Harcourt, near Mount Alexander, extensive quarries have been opened in it, from which very large solid masses have been extracted ; for instance, the square block, many cubic yards in size, covering the grave of Burke and Wills, the explorers, in the Melbourne General Cemetery ; those used for Burke's monument at Castlemaine ; and for Burke and Wills' monument in Mel- bourne, &c. Gellibrand's Hill, section 8, parish of Will-will- Rook, has also furnished good building stone ; for instance, for Prince's Bridge, the old Town Hall, and the Commissioners of Titles Office. A fine ornamental kind a syenite-granite, con- taining red feldspar and greenish hornblende occurs at Gabo Island and other places in Gippsland, that of the former place having been used for the General Post Office, the Custom House, and the Australasian Insurance Company's Offices. With regard to the moot point, whether granite is auriferous, i.e., contains gold impregnated or is traversed by auriferous quartz veins, the workings on the Nuggety Reef, near Maldon, have furnished valuable and interesting data. This celebrated reef, though it does not in fact traverse the granite itself, but terminates against it, is on the contrary, however, traversed by several granite veins, t The lines of contact of the reef-quartz and these * At the Elamore tin mine, near Inverell, New South Wales, " greisen" .occurs under quite similar circumstances. ir See note accompanying the Geological i sheet of the Maldon district. intrusive veins- are not, however, sharp and defined ; but the quartz becomes, by increasing accession of feldspar and mica, gradually transformed into granite, and within this zone of trans- formation, as it were, specs of gold and of the rare mineral maldonite (an - alloy of gold and bismuth) have been found in places quite richly impregnated. In the massive granite no gold has as yet been discovered. The auriferous character of the alluvial and older drifts of gullies and creek valleys, running through granite areas (for instance, at Beech worth, Maldon, Kingower,- Moliagul, &c.), can also not be considered as proof of the gold-bearing character of the rock, for the reason that the drift in its composition affords strong evidence of its being in part derived from denuded silurian rocks. In some cases this origin of the drift can be clearly established by the fact that the respective gullies and creeks rise in silurian ranges outside the granite areas ; but even where this latter feature does not obtain, we cannot otherwise explain the presence of silurian material in the drift than by supposing that silurian rocks once existed within the drainage area of such drift-channels. As regards accessory minerals, besides hornblende, black tour- maline (schorl), tin-ore and epidote, which constitute special varieties of the rock, the granites of the colony are, in comparison to those of other countries, rather poor. The most frequent are garnet, in fine crystals at Beechworth and Chiltern ; chlorite, in small nests, same localities ; fluorspar, in small patches, poorly crystallised, same localities ; amethyst, finely crystallised in druse- cavities and veins, same localities ; columbite, in small impreg- nated crystals at Maldon ; molybdenite, in small patches and crystals, at Yackandandah, Maldon, Mount Moliagul, &c.; iron- glance, in small plates and scales, at Mount Korong ; iron pyrites, in crystals and grains, generally distributed. It may also be mentioned that those peculiar mineralogical phenomena the so-called enhydros, or waterstones, i.e., irregularly polygonal, sharp angular bodies of chalcedony, with hollows inside, con- taining fluid and gas bubbles occur in decomposed granite beneath gold-drift at Beechworth. Felsite Porphyry. Several varieties of this species, as horne- stone porphyry, eurite porphyry, elvanite, quartz porphyry, &c., occur as dykes of sometimes considerable dimensions, and in larger intrusive masses. Of these latter, the best known are Mount Macedon, Dryden's Rock, and the Dandenong Ranges ; a patch in the valley of the Wannon, near Hamilton; and one, the most extensive, in Gippsland, at Buchan, bounding the Snowy River on the west. No minerals of any value have as yet been, found in this rock, which hitherto has only proved useful as a pretty good road metal. GRANITE. 1. GRANITE. Common ternary; coarse-grained, and rather feldspathic; contains orthoclase of bluish-white and pale pink colour; also small particles of whitish oligoclase. Excelsior Claim, Reed's Creek, Beechioorth. 2. GRANITE. Common ternary ; coarse-grained, and rather feldspathic ; contains some oligoclase. One-tree Hill, Beech- worth. 3. GRANITE. Common ternary. This specimen is composed of a coarse-grained, rather feldspathic portion in conjunction with a fine-grained rather quartzose one. Neighbourhood of Hensley's Tin-lode, fieechworth. 4. GRANITE. Common ternary ; rather coarse-grained and feldspathic ; some of the feldspar is oligoclase. Spring Creek, lliechu'orth. 5. GRANITE. Common ternary; rather coarse-grained; con- tains much oligoclase. Ten chains south of old slaughter-yard, Beechioorth. 6. GRANITE. Common ternary; fine-grained and very coarse- grained feldspathic portions mixed, the latter having in places the appearance of graphic-granite ; contains some oligoclase. Tail-race, Wooragee Creek, Heechworth. 7. GRANITE. Common ternary; medium-grained; quartz rather predominating and forming the largest grains; contains some oligoclase. Mount Alexander. Geological |- slieet 13 N. W. 8. GRANITE. Common ternary ; very coarse-grained and feld- spathic portion in conjunction with fine-grained one. From a vein in massive granite near Dargan's Creek. 9. GRANITE. Common, ternary ; very coarse-grained and feld- spathic ; contains some oligoclase. Station Peak, near Geelong. Geological % sheet 20 S.W. 10. GRANITE. Common ternary ; medium-grained ; in con- junction with black, dense, slightly porphyritic, metamorphic rock (hornfels). Baringhup. Geological sheet 14 S.W. 11. GRANITE. Common ternary ; rather coarse-grained quartz forming the largest grains. Harcourt quarries, near Mount Alexander. Geological | sheet 13 N. W. 12. GRANITE. Common ternary ; coarse-grained, feldspathic portion in junction with very fine-grained quartzose one; the 8 former shows some oligoclase. Station Peak, near Geelong. Geological \ sheet 20 S. W. 13. GRANITE. Common ternary ; coarse and fine-grained granite portions parted by a seam of fine-granular quartz. Station Peak, near Geelong. Geological \ sheet 20 S. W. 14. GRANITE. Common ternary ; rather fine-grained ; encloses large patches of orthoclase. Dog Rocks, near Geelong. 15. GRANITE. Common ternary ; rather fine-grained, with larger patches of feldspar and quartz. Dog Rocks, near Geelong. 16. GRANITE. Common ternary; medium-grained; contains some oligoclase. Mill-road, four miles from Beechworth. 17. GRANITE. Common ternary; fine-grained, with a slightly porphyritic aspect, due to enclosed larger patches of feldspar, smoky quartz, and black mica. Newtown quarries, Beechworth. 18. GRANITE. Common ternary, with but little mica; very coarse-grained ; feldspar slightly decomposed. Saddle in range east of Pound Creek, Beechworth. 19. GRANITE. Common ternary ; very coarse-grained and feldspathic ; mica of black and white colour ; encloses patches of schorl (black tourmaline). From a vein in silurian rocks near top of Mount Tarrangower. Geological sheet 14 S.W. 20. GRANITE. Common ternary ; very fine-grained portions poor in mica, mixed with highly micaceous ones, and enclosing krge patches and crystals of orthoclase. Ingleivood. 21. GRANITE. Same as No. 20. Ingleuood. 22. GRANITE. Common ternary ; coarse-grained portion in conjunction with fine-grained one ; encloses a large patch of crystallised schorl (black tourmaline) ; feldspar slightly decom- posed. From near Mount Tarrangower. Geological sheet US.W. 23. GRANITE. Common ternary; coarse-grained and rather feldspathic; feldspar slightly affected by decomposition. Mount Korong. 24. GRANITE. Common ternary coarse-grained ; quartz slightly predominating and forming the larger grains. Mount Kingower. 25. GRANITE. Common ternary ; very coarse-grained and traversed by veins of chalcedony. Spring Creek, Beechworth. 26. GRANITE. Common ternary; fine-grained. Spring Creek, Beechworth. 27. GRANITE. Common ternary, but poor in mica ; medium grained, and somewhat affected by decomposition ; rusty colour, due to percolation of ferruginous waters. Mount Beckwith. 28. GRANITE. Common ternary; coarse-grained and highly quartzose; portions consist of nearly pure quartz. North side of Pound Creek, Beechworth. 29. GRANITE. Common ternary, but very poor in quartz ; structure imperfectly laminated, resembling that of gneiss ; feld- spar slightly affected by decomposition. Pennyweight Flat, Beechworth. 30. GRA.NITE. Common ternary, but very poor in mica ; quartz of a dark smoky colour; contains a considerable per- centage of yellowish-coloured oligoclase. Mill-road, three miles from Beechivorth. 31. GRANITE. Common ternary; medium-grained, and rather feldspathic. The peculiar mode of the distribution of the black mica imparts to it a porphyritic aspect. Mount Korong. 32. GRANITE. Common ternary, but very poor in mica ; slightly affected by decomposition. Mount Beckwith. 33. GRANITE. Common ternary ; fine-grained and rather micaceous. Mount Beckwith. 34. GRANITE. Common ternary ; fine-grained and very micaceous. Mount Kingower. 35. GRANITE. Common ternary; main mass rather fine- grained, and rendered porphyritic by larger crystals of orthoclase and patches of quartz ; feldspar rather granular, and devoid of lustre on account of partial decomposition. Inglewood. 36. GRANITE Common ternary ; rather fiae-grained and poor in mica ; larger patches of feldspar impart to it a mottled appearance. Mount Beckwith. 37. GRANITE. Common ternary ; black mica strikingly predominating; medium-grained. Excelsior Claim, Reid's Creek, Beechworth. 38. GRANITE. Common ternary ; rather fine-grained ; mica scattered in small quantity. Bendigo. 39. GRANITE. Common ternary ; rather feldspathic ; medium- grained; occurs as pebbles in upper palaeozoic conglomerate. N.E. of Mia-mia. Geological % sheet N.E. Note 40. 40. GRANITE. Common ternary, but very poor in mica, flesh- coloured orthoclase predominating ; very coarse-grained ; would form a handsome building stone. Tail-race, Wooragee Creek, Beechworth. 41. GRANITE. Common ternary, but poor in mica; very coarse-grained and feldspathic ; feldspar of fine flesh-colour ; bears a strong resemblance to No. 40. Gabo Island. 42. GRANITE. Common ternary; contains black and white mica ; coarse-grained. Pyramid Rock, Phillip Island. 43. GRANITE. Common ternary ; flesh-coloured orthoclase .greatly predominating ; rather poor in quartz ; mica black, 10 green, and white ; encloses small patches of chlorite ; very coarse-grained. Gabo Island. 44. GRANITE. Common ternary, but poor in mica, mottled white and pink coloured orthoclase predominating ; medium- grained. Mount Beckwith. 45. GRANITE. Common ternary ; rather feldspathic, some of the feldspar being oligoclase ; medium-grained. Inglewood. 46. GRANITE. Common ternary, but very poor in mica ; one portion rather feldspathic and coloured brownish by ferruginous infiltrations ; in the remainder the black spots appear to be due to manganiferous brown iron-ore ; medium-grained. Mount Beckwith. 47. GRANITE. Common ternary ; in part very micaceous ; rather fine-grained. Mount Beckwith. 48. GRANITE. Common ternary; rather feldspathic ; medium- grained. Eastern slope of Mount Baw-baw, near Walhalla. 49. GRANITE. Common ternary ; a rather fine and even- grained mixture of white feldspar, quartz, and white mica, with a few small patches of black tourmaline (schorl), and a few grains of brown garnet ; some of the feldspar is triclinic (albite I) ; structure of the rock apparently tabular. Mount Korong. 50. GRANITE. Common ternary, but rather poor in mica ; medium-grained ; encloses large patches of quartz and orthoclase. From between Violet Town and Seymour. 51. GRANITE. Common ternary ; medium-grained ; encloses larger patches of quartz. From between Violet Toivn and Seymour. 52. GRANITE. Common ternary, but poor in mica, feldspar predominating ; very fine-grained. Mount Beckwith. 53. GRANITE. Common ternary ; very fine-grained ; consists of a rather decomposed highly feldspathic base enclosing larger patches of greenish- white mica. Tail-race, Wooragee Creek, Beechworth. 54. GRANITE. Common ternary, but poor in mica ; fine- grained very feldspathic base, rendered in part porphyritic by larger patches of quartz. Mount Beckwith. 55. GRANITE. Common ternary, but poor in mica; rather fine-grained. Mount Beckwith. 56. GRANITE. Common ternary, but very poor in mica ; fine- grained ; portion of a vein of coarse-grained granite containing oligoclase visible along one edge. Eiimemmering Greek, Robinson's Station. 57. GRANITE. Common ternary, rather feldspathic ; very 11 fine-grained. Back track to Wooragee, Beechworth. 58. GRANITE. Common ternary ; fine-granular mixture of orthoclase, some oligoclase, white mica, and quartz. Neighbour- Jwod of Ballarat. 59. GRANITE. Common ternary ; quartzose and very mica- ceous in part ; extremely fine-grained. From close to boundary of lower silurian rocks, Loddon River, near Mount Tarrangower. 60. GRANITE. Common ternary ; very micaceous and fine- grained. From close to boundary of lower silurian rocks, Loddon River, near Baringhup. Geological |- sheet 14 S. W. 61. GRANITITE. Common ternary; coarse-grained; contains quartz, much greenish-white oligoclase, flesh-coloured orthoclase, and little black mica. Occurs as pebbles in upper palaeozoic conglomerate north-east of Mia-mia. Geological |- sheet N.E. Xote 40. 62. GRANITITE. Common ternary ; very rich in greyish-green oligoclase, easily distinguishable from the flesh-coloured orthoclase ; medium-grained ; would form a handsome building stone. Pyramid Rock, Phillip Island. 63. GRANITITE. Common ternary ; fine-grained base, contain- ing much oligoclase, rendered porphyritic by patches of black mica and larger crystals and grains of flesh-coloured orthoclase and smoky quartz. Grampians. 64. GNEISS-GRANITE. Common ternary ; medium-grained ; very micaceous, the peculiar mode of distribution of the mica imparting to it a gneissose texture. Bucknall's Station, near Carisbrook. 65. GNEISS-GRANITE. Common ternary; fine-grained; very micaceous; the peculiar mode of distribution of the mica producing a gneissose texture. Part of the specimen in which this texture is absent is rendered porphyritic by larger crystals of orthoclase, and contains some oligoclase. Bendigo. 66. TIN-GRANITE. Common ternary, but very poor in mica ; coarse-grained ; contains cassiterite (tin-ore) and copper and arsenical pyrites finely impregnated. Gimblet's Tin locality, Beechworth. 67. TIN-GRANITE. Common ternary ; fine-grained; very poor in mica and rich in oligoclase ; contains small grains and crystals of cassiterite (tin-ore) and arsenical and copper pryrites disseminated through the mass, and is irregularly traversed by thin quartzose veins full of the same minerals. Gimblefs Tin locality, Beechworth. 68. TIN-GRANITE. Common ternary; rich in silvery-white mica ; medium-grained ; contains grains of cassiterite scattered 12 through the mass; rather friable on account of partial decompo- sition of the feldspar. Hensley's Tin-lode, Beechworth. 69. GREISEN. Binary; composed of granular quartz with patches of white and greenish-grey mica ; contains scattered grains of tin-ore. (See introductory remarks under Granite.) Neighbour/Mod of Hensley's Tin-lode, Beechivorth. 70. HALF-GRANITE (Aplite). Binary ; quartz and orthoclase ; coarsely porphyritic. The orthoclase crystals are twins of the Baveno type. From a dyke in common ternary granite near Bradford. Geological ^ sheet 1 4 N. W. 71. HALF-GRANITE (Aplite). Binary; quartz and orthoclase ; coarsely porphyritic. The orthoclase crystals, though rather imperfect, appear, like in No. 69, to be twins of the Baveno type. Station Peak, near Geelong. Geological | sheet 20 S. W. 72. HALF-GRANITE (Aplite). Binary ; quartz and orthoclase, the former greatly predominating, the latter more or less decomposed. The peculiar layer-like mode of distribution of the feldspar produces a rather imperfectly laminated structure. Back track to Wooragee, Beechworth. 73. HALF-GRANITE (Aplite). Binary. This specimen consists of a porphyritic portion a white fine granular feldspathic base enclosing quartz grains which graduates into a dense intimate mixture of much quartz and some feldspar, conforming to felsite, or so-called " haelleflinta." Breakneck track, Reid's Creek, Beechworth. 74. HALF-GRANITE (Aplite). Binary ; medium-grained ; an even mixture of quartz and white orthoclase, rendered porphyritic by larger grains and crystals of orthoclase of a light flesh-colour. From a dyke in common ternary granite, Mount Alexander. 75. HALF-GRANITE (Aplite). Binary; quartz and orthoclase with a few scattered scales of mica ; the feldspar slightly affected by decomposition. Mount Beckunth. 76. . HALF-GRANITE (Aplite). Binary ; quartz and orthoclase, the latter slightly predominating; rather fine-grained. Mmmt Beckwith. 77. HALF-GRANITE (Aplite). Binary; fine-granular rather feldspathic base, composed of quartz and orthoclase, rendered porphyritic by small patches of quartz and a few scales of mica. Mount Beckwith. 78. HALF-GRANITE ( Aplite). Binary ; quartz and orthoclase with a few scales of mica ; rather fine grained. Mount Beckioith. 79. HALF-GRANITE (Aplite). Binary; very fine-grained uniform mixture of quartz and feldspar, the latter rather 13 predominating ; approaches felsite in appearance. Riddell's Creek, near Mount Macedon. 80. HALF-GRANITE (Aplite). Binary ; fine-grained mixture of quartz and orthoclase with larger patches of both minerals interspersed. Loddon River. 81. HALF-GRANITE (Aplite). Binary; very fine-grained mixture of quartz and orthoclase. From the " Hanging Rock" dyke, near Heathcote. (Geological Note by Mr. Norman Taylor. This dyke, which lies to the westward of the Heathcote township, is in places of an ordinary granite character ; in others it passes into eurite. The most prevailing colour is of a light-brown passing into light-green. In width it varies from two to five chains, and is traceable for four miles south of the Kyneton road-cutting, where it appears to pass into a thin granite dyke, accompanied by greenstone. It is extensively used in Heathcote both for building and kerbiug, the harder varieties being well adapted for these purposes. It has also been used for making filters, or " drip-stones." The dyke has, probably, some connection with one occurring in the area of Geological | sheet 51 S.W.) 82. HALF-GRANITE (Aplite). Binary ; fine-grained mixture of quartz and principally orthoclase. Button Grange, near Mount Alexander. Geological ^ sJieet 15 N. W. 83. HALF-GRANITE (Aplite). Binary ; very fine-grained mixture of quartz and orthoclase. Dyke under Mount Ida Hotel, Heathcote. 84. HALF-GRANITE (Aplite). Binary; much decomposed feldspar and greenish mica. Pyrenees. 85. HALF-GRANITE (Aplite). Binary; quite decomposed feldspar and quartz ; medium-grained. Pennyweight Flat, Beechworth. 86. EPIDOTE-GRANITE. Ternary; flesh-coloured orthoclase, green " epidote" (pistacite), and some quartz ; medium-grained. Head of Nuggety Gully, near Talbot. 87. TOURMALINE-GRANITE. Quaternary; a crystalline, fine- granular mixture of white feldspar, quartz, white mica, and black tourmaline (schorl), with a few grains of brown garnet ; some of the feldspar is triclinic (albite ?) ; structure of the rock apparently tabular. Resembles No. 49, but contains more tourmaline. Bendigo District. 88. SYENITE-GRANITE. Ternary ; consists of flesh-coloured orthoclase, hornblende, and quartz ; medium-grained. A fine ornamental building stone, but expensive to work. Used in the General Post Office, the Australasian Insurance Company's 14 offices, for gravestones, &c. Gabo Island. 89. SYENITE-GRANITE. Ternary; medium-grained; composed of flesh-coloured orthoclase, some greenish-white oligoclase, hornblende, and quartz. Would form a fine ornamental building stone, though, like No. 88, expensive to work. Gippsland. 90. SYENITE-GRANITE. Ternary ; fine-grained ; composed of feldspar, quartz, and hornblende ; some of the feldspar appears to be oligoclase. From a dyke in Van der Luffs paddock, near Heathcote. 91. SYENITE- GRANITE. Ternary ; a fine-grained base, com- posed of feldspar, quartz, and hornblende, rendered porphyritic by irregular-sized patches and crystals of feldspar. From a dyJce in south-west corner of Geological - sheet 51 8. W. 92. SYENITE-GRANITE. Quaternary ; brecciated-looking mix- ture of portions of common ternary, coarse and fine-grained granite, rendered porphyritic by crystals of black "hornblende;" a considerable percentage of the feldspar showing a light-greenish colour is "oligoclase." Mount Kingower. 93. SYENITE-GRANITE. Quaternary ; medium-grained, com- mon ternary granite with abundance of " oligoclase," rendered porphyritic by largish crystals of black " hornblende." Mount Kingower. 94. SYENITE-GRANITE. Quaternary ; medium-grained com- mon ternary granite base, rendered porphyritic by crystals of black " hornblende," and coloured brownish-red by hydrous oxide of iron ; part of the feldspar appears to be " oligoclase." Mount Beckwith. 95. SYENITE-GRANITE. Quaternary ; fine-grained common ternary granite base, rendered porphyritic by crystals of black "hornblende" and of both "orthoclase" and "oligoclase."- Bendigo. 96. DECOMPOSED GRANITE (Kaolin Rock). Feldspar entirely decomposed to kaolinite, through which quartz grains are sparingly distributed ; mica completely removed ; valuable for china manufacture. Deep Creek, near Eulla. Geological |- sheet 7 S.E. 97. DECOMPOSED GRANITE (Kaolin Rock). Same as No. 96. Mount Kingower. 15 GRANITE PORPHYRY. This species, which stands intermediate between granite and felsite porphyry, is represented in the collection by but a few and not very characteristic specimens. Several very fine and characteristic ones are contained, however, in the collection of rocks from New South Wales. 98. GRANITE PORPHYRY. Extremely fine-grained binary base, composed of feldspar and quartz, full of crystals of orthoclase and quartz ; those of the latter representing mostly the double hexagonal pyramid, with no, or but occasional very small, planes of the hexagonal prism. Back Creek, east of Spring Plains. Geological ^ sheet 51 S.W. 99. GRANITE PORPHYRY. Very fine-grained, common ternary granite base, showing imperfect crystals and patches of quartz, and accumulations of scales of greyish-green mica ; encloses also pseudomorphs of brown iron ore after iron pyrites. M'Intyre Diggings. 100. GRANITE PORPHYRY. Common ternary, very fine-grained granite base, poor in mica, with larger and smaller crystals of orthoclase, oligoclase, and dark-coloured quartz. One-tree Hill, Beechworth. 101. GRANITE PORPHYRY. Common ternary, very fine-grained granite base, with crystals of quartz, orthoclase, and mica, the latter rather prominent. Brewery Springs, near Maldon. 102. GRANITE PORPHYRY. Extremely fine-grained, nearly dense, binary granite base, composed of feldspar and quartz, enclosing crystals of orthoclase and small granular black patches, consisting of scales of black mica. North-east of Baynton. Geological J sheet 51 S.W. 103. SYENITE-GRANITE PORPHYRY. Fine-grained, common ternary granite base, enclosing crystals of hornblende and large crystals of orthoclase. West of Lancefield-road, south of parish of Baynton. Geological - sheet 5 N. W. 104. SYENITE-GRANITE PORPHYRY. Very fine-grained, qua- ternary, rather quartzose, granite base (quartz, mica, hornblende, and orthoclase), with large crystals of hornblende and feldspar ; the latter consisting of both orthoclase and oligoclase. Mount Kingower. 105. SYENITE-GRANITE PORPHYRY. Fine-grained, quaternary granite base (feldspar, quartz, mica, and hornblende), enclosing large crystals of hornblende, mica, and feldspar ; some of which latter appears to be oligoclase. Heathcote. 16 106. SYENITE-GRANITE PORPHYRY. Fine-grained syenite- granite base (orthoclase, quartz, and hornblende), with larger crystals of feldspar and hornblende. From a dyke at south-west corner of Geological ^ sheet 51 S.W. FELSITE-FELSITE PORPHYRY. Of this species the collection contains a number of fine characteristic specimens, representing most of the known varieties. Some of these varieties are called by various names, which have been noted both on the descriptive labels and in the sequel. 107. FELSITE (Feldstone, Elvanite.) Dense siliceo-feldspatbic rock. From between Violet Town and Seymour. 108. FELSITE (Feldstone, Elvanite). Dense siliceo-feldspathic rock, similar to 107. From a hill 12 miles north of Sandhurst. 109. FELSITE (Feldstone, Elvanite). Same as 108. 110. FELSITE (Feldstone, Elvanite). Extremely fine-grained, nearly dense rock, with imperfect slaty cleavage, consisting of an intimate mixture of quartz and feldspar, of which the former greatly predominates. The black markings appear to be of a dendritic character, caused by oxide of manganese. From a dyke running along Suriper's Reef, Maldon. 111. FELSITE (Feldstone, Elvanite). Siliceo-feldspathic rock ; rather porous. Similar to 107 and 108. Heathcote. 112. FELSITE. A light greenish-coloured felsitic rock, traversed and rendered breccia-like by innumerable veins and nests of quartz From a dyke in granite, Spring Creek, Beechworth. 113. FELSITE PORPHYRY (Feldstone Porphyry, Eurite Por- phyry, Elvanite). Yellowish- white felsitic base, enclosing rather small crystals of quartz (mostly perfect double hexagonal pyramids) and orthoclase. Bank of the Yarra River, betiveen Prince's Bridge and the Botanical Gardens. Geological ^ sheet 1 S.E. 114. FELSITE PORPHYRY (Feldstone Porphyry, Elvanite). Yellowish-white, rather dull felsitic base, with crystals of orthoclase, hornblende, patches of greenish-white mica, and occa- sional grains of quartz. Gippsland. 115. FELSITE PORPHYRY (Eurite Porphyry, Quartz Porphyry, Elvanite). Dense, white, apparently pure feldspar base, enclos- ing grains and crystals of quartz. This rock has some resem- blance to the species " granulite" or " leptynite." Dunolly. 116. FELSITE PORPHYRY (Feldstone Porphyry, Quartz Por- phyry, Elvanite). Whitish, rather dull felsitic base, with grains 17 and crystals of quartz ; appears to be indistinctly laminated ; -the black spots are apparently, as on No. 110, of a dendritic oh aracter. Kingower, 117. FELSITE PORPHYRY (Feldstone Porphyry). Bluish-grey, very fine-granular, siliceo-feldspathic base, with rather scattered crystals of orthoclase and quartz. Loddon River, near Maldon. 118. FELSITE PORPHYRY (Hornstone Porphyry). Dense, brown, hornstone-like base, densely impregnated with crystals of orthoclase and grains of quartz ; a few scattered mica scales and grains of almandine garnet are also observable in places. Kingower. 119. FELSITE PORPHYRY (Hornstone Porphyry). Dense, brown base, with rather small crystals of reddish orthoclase and grains and crystals of dark-coloured quartz. From between M-Jvor and Sandhurst. 120. FELSITE PORPHYRY (Hornstone Porphyry). Dense greenish-grey, hornstone-like base, enclosing crystals of flesh- coloured orthoclase and grains of quartz. Upper Wannon Falls. 121. FELSITE PORPHYRY (Hornstone Porphyry). Base greyish- black ; otherwise same as 120. Upper Wannon Folk. 122. FELSITE PORPHYRY. Very fine-granular, greyish-black base, with crystals of feldspar, some of which appear to be triclinic. West of Mount Disappointment, Upper Plenty River Geological sheet 3 N.E. 123. FELSITE PORPHYRY (Hornstone Porphyry). Dense, black, hornstone-like, brecciated- looking base, enclosing grains of quartz and in less quantity small crystals of flesh-coloured orthoclase. Dandenong Ranges. 124. FELSITE PORPHYRY. Dense, yellowish-grey base, densely impregnated with crystals of orthoclase and grains of quartz; slightly affected by decomposition around the margin. Bendigc. 125. FELSITE PORPHYRY (Feldstone Porphyry, Quartz Porphyry, Elvanite). Very fine-granular, siliceo-feldspathic base, with crystals of quartz (frequently perfect double hexagonal pyramids) and a few scattered crystals of feldspar. M'Intyre. 126. FELSITE PORPHYRY (Feldstone Porphyry, Elvanite). Greenish-white, siliceo-feldspathic base, with crystals of feldspar and grains of quartz ; the former affected by decomposition. From between Violet Town and Seymour. 127. FELSITE PORPHYRY (Feldstone Porphyry, Elvanite). The same as 126. 128. FELSITE PORPHYRY (Feldstone Porphyry, Elvanite). JDull yellowish-white, siliceo-feldspathic base, with scattered 18 scales of greenish-white mica, thin needles of hornblende, and a few quartz grains; affected by decomposition round the margin. Loddon River. 129. FELSITE PORPHYRY (Elvanite). Very fine granular, siliceo-feldspathic base, full of grains and crystals of quartz, orthoclase, and hornblende. From between Violet Town and Seymour. b. QUARTZLESS ORTHOCLASE ROCKS. Rocks belonging under this head, in which quartz does not form an essential component, though it may occasionally occur as an accessory, are apparently very rare in Victoria, and the collection contains only three specimens, representing the species " syenite" and " syenite porphyry" (quartzless orthoclase porphyry). 130. SYENITE. Medium-grained mixture of flesh-coloured orthoclase and greenish-black hornblende, with scattered particles of chlorite and a few quartz grains. Head of Nuggety Gully, Talbot. 131. SYENITE. Fine-grained mixture of much flesh-coloured orthoclase, little hornblende, epidote, and a few scales of mica and grains of quartz. Traversed by seams of dense green epidote (pistacite). Omeo-road, Gippsland. 132. SYENITE PORPHYRY (Quartzless Orthoclase Porphyry). Fine-granular, syenitic base (apparently composed of hornblende and feldspar), with crystals of very glassy-looking orthoclase. Brock's Monument, north-east of Mount Macedon. Geological sheet 6 N. W. 2. ROCKS IN WHICH THE PREDOMINATING FELDSPAR IS TfilCLINIC (PLAGIOCLASE). a. OLIGOCLASE ROCKS. DIORITE AND ALLIED ROCKS. The rocks of this class, essentially compounds of oligoclase and hornblende, occasionally associated with quartz and mica, are also known under the general term " greenstone" " horn- blendic greenstone" in contradistinction to the " augitic green stone," " Diabase," not yet observed in Victoria. They occur in our colony mostly as dykes, varying from a few to several 19 hundred feet in thickness, traversing upper silurian rocks, and are represented in the collection in nearly all the varieties of texture and mineral composition mentioned in text-books. These dykes are, as mining features, of special interest and importance, because they have nearly, as a rule, been found impregnated with auriferous pyrites, and traversed by or associated, either on the hanging or foot-walls, or on both walls, with auriferous quartz veins, partly regular, partly quite irregular, in course, extent, and richness. In fact, it may be affirmed that by far the greater quantity of the quartz-gold produced by the goldfields occupied by upper silurian rocks, is derived from such diorite dykes. As some of the dykes celebrated in this respect may be mentioned the large dyke of the Morning Star Hill, Wood's Point ; that of the Loch Fyne Company, near Matlock ; at Gaffney's Creek those of the Eldorado and Wallaby companies ; and a very important one which has been opened for four to five miles in length, and has been for years successfully worked by the Rose of Denmark Company at its northern, and by the Castle Reef and Al companies at its southern end, with numerous rich claims intermediate. In Gippsland we have rich dykes at Donnelly's Creek j and at Walhalla, besides that of the Longfellow's Company, the dyke of the celebrated Cohen's Reef, perhaps the richest one in the colony. Some of the specimens from it shown, in the collection, represent the variety " diorite aphanite," and can hardly be distinguished from those derived from the dyke of the Rose of Denmark Company, Gaffney's Creek. At Crossover Creek, North Gippsland, the dyke of the Albion Company is interesting, on account of its highly micaceous character, and the clear evidence it affords of the favourable influence of the dyke upon the gold-bearing character of the reefs traversing it at right angles to its strike. For whilst these reefs are but very poorly auriferous in the upper silurian slate, into which they continue on either side, they become even richly gold-bearing throughout the width of the dyke (about 90 feet). Another place where a great number of diorite dykes occur, most of which have proved auriferous, is Alexandra ; but they are there very much decomposed a feature shown by most dykes, in a stronger or lessdegree, to varying sometimes considerable depths beneath the surface. With regard to the question whether the strike or direction and angle of dip of dykes, texture or mode of com- position of the rock i.e., whether coarse or fine-grained, or the predominance of either feldspar or hornblende have any bearing upon the auriferous character of the traversing or associated quartz veins, no conclusive observations have as yet been made. c2 20 Judging from a number of well-known dykes, it seems, however, as if neither of these features has any influence in this respect. Whilst, for instance, the dyke of Cohen's Reef, Walhalla, and the extensive one at Gaffney's Creek, above noticed, are for the greater part of an aphanitic, highly feldspathic character, the equally rich dykes of the Morning Star Hill, Loch Fyne, Eldorado, Wallaby, &c., are coarse-granular and highly horn- blendic, and their strikes and dips are also different. There is another feature in connection with some of these dykes which deserves special notice namely, that they show in strike and dip great changes both in texture and composition. For instance, the extensive dyke of Gaffney's Creek, and, in a less degree, the dyke of Cohen's Reef, are in some parts distinctly crystalline-granular, i.e., show a granitic texture with triclinic feldspar and hornblende plainly perceptible, whilst for the greater part opened they are micro-crystalline-granular, apparently quite dense, light greenish-grey feldstone-like with neither horn- blende nor feldspar recognisable. In fact, if it was not for the occasional changes in texture and composition just mentioned, the rock would sooner be taken to be a true feldstone than as belonging to diorite, representing the variety feldspathic diorite- aphanite. A fine illustration of both a textural and mineralogi- eal change combined exhibits the dyke on which the Thomson River copper-mine has been opened. The copper-ore-bearing part is here a coarse-granular, highly hornblendic diorite in fact, nearly pure hornblende rock in places which forms " shoot- like," the northern termination of the dyke, whilst southward in strike it changes within a very short distance, through fine- granular to a nearly dense, highly feldspathic aphanite, closely resembling the rock of the Cohen's Reef and Gaffney's Creek dykes, just spoken of. ( 133. DIORITE. Granular mixture of hornblende and oligo- clase, with scattered quartz grains. Near south-east corner of section 15, parish of Metcalf. Geological sheet 13 S.E. 134. DIORITE. Rather coarse-granular and hornblendic. Eastern side of right-hand branch of Stringer's Creek, Walhalla. 135. DIORITE. Coarse-granular and highly hornblendic; forms the northern termination of a strong dyke, and represents the "lodestone" of the Thomson River copper mine, being in parts densely impregnated with copper and iron-pyrites, and traversed by irregular larger and smaller veins of these ores, intimately mixed. Southward in strike it changes to a dense, feldspathic aphanite (see No. 150). Thomson River copper mine, near Walhalla, North Gippsland. 21 136. DIORITE. Crystalline-granular, medium-grained ; strongly impregnated with iron pyrites. Dyke of the Eureka mine, about three-quarters of a mile east of Walhalla, North Gippsland. 137. DIORITE. Medium-grained, and rendered slightly por- phyritic by small patches of quartz and crystals of triclinic feldspar and hornblende ; impregnated with iron and magnetic pyrites. East of Lancefield. Geological % sheet 5 S.E. MR. NORMAN TAYLOR'S NOTE. The greenstone (diorite) com- posing the range to the east of the parish of Lancefield is very variable in its lithological character. Mount William, at the extreme northern and highest part of the range, and at its jun'ction with the Great Dividing Range, is composed of a very hard, dark-greenish black, dense (aphanitic) rock, closely resembling a basalt, and with a metallic ring when struck, like " clinkstone," passing southwards to a Tighter green, hard ' rock, with crystals of triclinic feldspar, sometimes having the appearance of a greenish-white rock, with black, dendritic (horn- blendic) markings. This stone (see building-stone Cubes R, 30, 31, 32), were it not for its extreme hardness, and consequent difficulty and expense in quarrying and working up, would make a very handsome stone for building or ornamental purposes. Further south it passes into a black, highly crystalline, horn- blendic rock, and then again to a dark-green, dense rock with specks of iron pyrites. Near the centre of this range (see j sheet 5 S.E.) is a fault, cutting off the greenstone. Its place is supplied by a very rich and heavy brown iron -ore or brown hematite (see Mineral Collection, National Museum, case 13, No. 36). The greenstone weathers externally to a rusty-brown colour. The unfossiliferous silurian shales resting as small outliers on the top of this greenstone range (probably the remains of a denudation of the formation up-heaved by it), and also the contiguous rocks on the west side, are all highly metamorphosed, the shales being converted into a hard jaspery porcelanite. About a mile north-east of Mount William is the site (locally called " The Native Tomahawk Quarries") whence the aboriginal tribes of the neighbouring districts have procured the greenstone used by them for making tomahawks. From the amount of broken stone covering a large area, this quarry must have been in use for a very lengthened period. 138. DIORITE. Fine-granular; contains scattered specks of iron pyrites. Loddon River. 139. DIORITE. Fine-granular and very even-grained. Lod- don River. 140. DIORITE. Fine-granular and slightly porous; affected 22 by decomposition. Loddon River. 141. DIORITE. Fine-granular, highly feldspathic, much de- composed ; traversed by a small quartz vein, and slightly impregnated with crystals of iron pyrites. From a dyke traversed with auriferous quartz veins, South LongfelloufsCompanyls ground, near Walhalla, North Gippsland. 142. DIORITE. Fine-granular ; strongly affected by decom- position ; full of patches and irregular veins of partly crystallised iron pyrites. From the, gold-bearing dyke of Hunt's Claim, Ga/ney's Creek. 143. DIOKITE. Granular; medium-grained; strongly affected by decomposition. From the gold-bearing dyke, the so-called " Cohen's Reef" Wallialla, North Gippsland. 144. MiCA-DiORiTE. A rather coarse-granular mixture of somewhat gneissose texture of oligoclase, mica, and quartz ; conforms in composition to the rock described as " kersantite," occurring in the Vosges mountains, France. Van der Luft's paddock, near Heathcote. 145. MICA-DIORITE (Mica-Porphyrite). Fine-granular, feld- spathic, apparently chloritic and somewhat decomposed diorite base, rendered porphyritic by hexagonal plates of brownish-black mica and a few crystals of feldspar and hornblende ; strongly impregnated with grains of copper and iron pyrites ; conforms to the rock described as " kersanton," occurring in Brittany, France. From a dyke traversed by highly auriferous quartz veins at Crossover Creek, North Gippsland. 146. DIORITE- APHANITE. An extremely fine-grained, appa- rently dense diorite, rendered micro-porphyritic by very slender prismatic crystals of hornblende. Den Hilh, near Montham. 147. DIORITE-APHANITE. Apparently dense homogeneous base, rendered slightly porphyritic by crystals of triclinic feldspar (oligoclase) ; contains scattered specks of copper pyrites. Dyke under Mount Ida Hotel, Heathcote. 148. DIORITE- APHANITE. Microcrystalline-granular ; quite dense and compact looking ; highly feldspathic ; encloses crystals of iron pyrites, and shows on one side a crystalline coating of bitterspar, in which is embedded a small speck of gold. From the auriferous dyke of the A 1 Company, Castle Reef, Raspberry Creek. 149. DIORITE-APHANITE. Microcrystalline-granular ; quite dense and compact looking ; highly feldspathic ; traversed by veins of auriferous quartz and arsenical pyrites, and strongly impregnated with crystals of iron pyrites and slender prismatic crystals of arsenical pyrites. From the auriferous dyke, the so-called 23 " Cohen's Reef" Wal/talla Company's mine, Wallialla. 150. DiORiTE-ApHANiTE. Microcrystalline-granular ; appa- rently dense, felsite-like ; highly feldspathic, and rather calcareous ; traversed by quartz veins. Forms the modification southward in strike of tlie Jiornblendic, cupriferous, diorite dyke of the Thomson River copper mine, Walhalla (see No. 135). 151. DIORITE PORPHYRY (Aphanite Porphyry). Microcrys- talline-granular ; aphanitic diorite base, densely charged with small crystals of white triclinic feldspar (oligoclase ]) ; a few scattered needles of black hornblende are also observable. "Hanging Rock" dyke, near Heathcote. Geological | sheet 51 N. W. 152. DIORITE PORPHYRY (Aphanite Porphyry). Dense, greenish-black aphanite base, with crystals of whitish oligoclase, and scattered, small patches of very fine-scaly mica. North-east of Baynton, county of Dalhousie. 153. DIORITE PORPHYRY. Finely crystalline-granular, greyish diorite base, with crystals of white oligoclase and black horn- blende. Dyke two miles north of the Green Hill, near Malmsbury. 154. DIORITE PORPHYRY (Aphanite Porphyry). Dense, greenish-black aphanite base, with crystals of triclinic feldspar and grains of quartz. Loddon River. 155. DIORITE PORPHYRY. Finely granular, micaceous diorite base, with crystals of triclinic feldspar and hornblende ; strongly affected by decomposition. Intrusive patch near Tarilta. Geological sheet 16 N.E. Geological Note. This specimen comes from a peculiar intrusive mass of rock, several acres in extent, that, in most places where exposed, consists of diorite (pinkish triclinic feldspar and black hornblende), but assumes at others granitic, syenitic, porphyritic, and brecciated characters. Thus at its junction with the black graptolite slates of the neigh- bourhood, where several small faults have been traced (see sketch on geological |- sheet 15 N.E.), the rock bears the character of a porphyry, more or less decomposed (specimen 155) ; whilst at another place, scarcely four chains off, the accession of black mica and some quartz renders the rather decomposed rock undistinguishable from decomposing granite ; and from one of the small shafts sunk for the purpose of examination, specimens of 4f epidosite" (see specimen 239) were also obtained. In small cavities of the porphyritic variety, crystals of " albite," associated with abnormally formed quartz crystals, occur, and it was there- fore probable that the feldspar entering into the composition of the rock might also be " albite," though the absence of the characteristic twin-striation on its cleavage planes gives it all the -appearance of " orthoclase." The following results of an analysis 24 by Mr. J. Cosmo Newbery, viz. Silica, 67 - 70 ; alumina, 20*50 ; sesquioxide of iron, traces ; lime, traces ; magnesia, traces ; potassa, traces ; soda, 10 '00 proves it, however, clearly to be " albite," and the rock is therefore a diorite according to recent views on petrographical classification. The adjoining fossiliferous strata are not, or but very slightly, altered, and hand-specimens can easily be obtained, of which one half (of a specimen) consists of black slate, with well-preserved graptolites, and the other of the porphyritic variety of the intrusive rock. The brecciated variety, apparently a mixture of chips of silurian rock and of the dioritic paste, occurs only here and there along the boundary of the two formations. PORPHYRITE AND ALLIED ROCKS. 156. MICA-PORPHYRITE. Microcrystalline-granular, dark, feld- spathic base, with crystals of triclinic feldspar, abundant hexagonal plates of dark bronze-brown mica, and a few scattered quartz grains. From the Black Spur, near Fernshaw. 157. MICA-PORPHYRITE. Same as No. 156. 158. MICA-PORPHYRITE. Same as No. 156, only feldspathic base of lighter colour. From the Black Spur, near Fernshaw. 159. FELDSPAR-PORPHYRITE. Microcrystalline-granular, dark- green, probably chloritic feldspar base, with crystals of triclinic feldspar, grains of quartz, and small, greenish-black, scaly patches of probably a " bydromica." Black Spur, near Fernshaw. 160. FELDSPAR-PORPHYRITE. Very finely-crystalline-granular base, enclosing larger and smaller grains of quartz, crystals of triclinic feldspar, and small scales of black mica those of feldspar being predominant and most striking. From a dyke east of J3mberton. Geological sheet 13 S.E. 161. FELDSPAR-PORPHYRITE. Same as No. 160, but mica very scarce. Dyke east of Emberton. Geological ^ sheet 13 S.E. b. LABRADORITE ROCKS. Rocks of this class are only known as yet from two localities in Victoria, though judging from the occurrence of serpentine the general associate of some species (gabbro, &c.) in the Gippsland ranges, more localities will most likely be found there on further exploration of the country. 162. GABBRO, DIALLAGE ROCK. A coarsely-crystalline- granular mixture of light-green " labradorite," and of a dark- 25 green augitic mineral, which according to its lustre and cleavage is " diallage." Barmbool Hills, west of Geelong. Geological I sheet 24 S.E. 163. GABBRO, DIALLAGE ROCK. Same as No. 162. On one side affected by decomposition, the feldspathic component being in places wholly removed, leaving the diallage behind as an irregular hackly surface of interwoven crystals. Note. This rock occurs as a pretty extensive mass, sur- rounded by mesozoic carbonaceous rocks, principally sandstone ; but is evidently older than the latter, on account of their being interstratified with beds of coarse conglomerate, partly composed of rounded pebbles of it. On account of its fine colour and texture, it is well adapted for ornamental purposes, though its- great hardness and toughness renders it rather expensive to work. On some specimens diallage has been observed of a darker colour than the rest, and with the angle of cleavage of hornblende, which would indicate an alliance to uralite. The following are the results of analyses of the rock by Mr. J. Cosmo Newbery : Analysis of the Hock in mass. Soluble Portion. Insoluble Portion. Silica ... 50-84 46-34 53-94 Iron sesquioxide Iron protoxide Alumina Lime ... 0-52 6-99 12-92 14-35 1-30 2905 14-56 11-78 2-80 14-39 Magnesia ... Soda ... 10-97 traces 3-44 ) 16-13 Potassa Loss by ignition Water 1-83 0-71 f 4-51 1-75 99-13 100-95 99-04 40-06 per cent, is soluble in hydrochloric acid, and the analysis of this portion proves it to be labradorite, whilst that of the insoluble one comes very near to the mean composition of diallage. 164. GABBRO, DIALLAGE HOCK. Very large-grained ; nearly wholly composed of interlacing crystals of greyish and greenish diallage, showing cleavage planes of fine pearly lustre, with but little, more or less decomposed, triclinic feldspar (labradorite) between. From the Serpentine of Mount Wellington, Gippsland* 26 B. NEWER FELDSPAR ROCKS ; NEWER IGNEOUS OR VOLCANIC ROCKS. Of the four series of rocks belonging under this head viz., the trachyte rocks, nepheline and leucite rocks, basalt rocks and .younger anorthite rocks only the third the basalt rocks have as yet been observed in Victoria, though it is not impro- bable that some rocks from certain localities classed amongst them may belong to the nepheliue series, as will be explained further on. As trachyte rocks exist in the neighbouring colony of New South Wales, and more extensively further north in Queensland, they may perhaps also occur in this colony in the ranges near the boundary of New South "Wales ; but this could only be in small outcrops or dykes ; for that they should exist massively developed and be hitherto overlooked is extremely doubtful, as the country is too well explored. BASALT ROCKS. These rocks, which are essentially composed of auyite, labra- dorite, and titaniferous magnetic iron, are extensively developed in Victoria, being estimated to occupy from GOOD to 7000 square miles of the surface. Their eruption took place during at least two distinct periods within tertiary times, and they are therefore divided into older and newer basalt rocks. The older basalts apparently the more widely distributed appeared at the end of the miocene epoch, whilst the eruption of the newer commenc- ing towards the close of the pliocene epoch seems to have been continued into the most recent post-pliocene times. In its phy- sical features the country occupied by these two basalts differs generally very much, and the geological observer has no difficulty in determining the nature of the rock. The older basalt country exhibits gently sloping rises with occasional higher smooth hills, the surface above the rock consisting of several feet in places up to 10 feet and more of a very fertile black, brown, or chocolate-coloured soil, which is doubtless the result of long- continued decomposition of the rock. It supports the most profuse and dense vegetation, hardly penetrable scrubs and forests, in which the trees of all kinds frequently reach gigantic dimensions 10 to 12 feet in diameter at the base, and up to 300 feet and above in height, being not uncommon amongst some of the eucalypti as, for instance, in the ranges east of Berwick, along portions of the Gippsland road, and in the Western Port District. As another effect of the long-continued action of decom- 27 posing agencies, the structure of the rock, though sometimes iinely columnar or prismatic, is most frequently sphaeroidal, poly- gonal, concretionary, and much jointed characteristic features, which destroy the use of the rock as a building stone com- pletely, but do not affect its applicability for road and railway- ballast metal, for which purposes it deserves indeed to be extensively used. Alternating with these hard layers are generally such of an unctuous, frequently amygdaloidal, soft clay, which shows all variations of colour from pure white to dark red, dependent on the amount of hydrous oxide of iron admixed. In some places this clay is thickly traversed in all directions by ferruginous masses, which exhibit in section a concentric shell- like structure, due to the effects of advancing decomposition, and pointing to their representing but the nuclei of larger, irregularly- polygonal masses that originally composed the whole mass of the layer the clay now intervening being the result of the com- plete decomposition of successive concentric coats of these poly- gons. These various structures are well exemplified in the North Melbourne Railway and the Flagstaff Hill road-cuttings, but occur most extensively developed on the south coast of Phillip Island, on the shores of Western Port Bay, in the Pent- land Hills, near Bacchus Marsh, &c. Considering the mode of eruption of the older basalt, the absence of real craters, and the general scarcity, and in some districts total absence, of points of eruption, is very remarkable, and seems to indicate that the rock mostly issued from large fissures or gigantic dykes ; whilst some of the smaller dykes, abundant in some dis- tricts (Cape Patterson, Western Port, &c.) may also have contri- buted their share to the outpour. On this account the specimens in the collection have been classed simply as basalt, and not as basalt-lava, the term lava being generally applied only to those rocks which have issued from, or whose origin can distinctly be traced to, craters or unmistakeable volcanic vents. The newer basalt has in this respect, in contrast to the older, to be called a lava ; for its extensive sheets and streams can in every case be traced either to distinct craters or to points of eruption, which latter seem in many instances to be filled-up craters, and show by scoria and cinders, abundantly strewn over their summits and slopes, plain evidence of their original office. As some of the principal craters may be mentioned Mount Franklin, Tower Hill, Mount Eels, Mount Noorat, Mount Napier, Ac.; whilst of the great number of conical or mammaloid points of eruption, the three Anakies, Mounts Glasgow, Hepburn, Buninyong Kangai-oo 28 Hill, Carisbrook Hill, &c., form well-known examples.* In contrast to that occupied by the older basalt, the newer basalt country presents thus generally wide, open, mostly rocky plains, studded in parts with conical hills and mountains ; only in rare instances the plains are covered with forest trees, but not by far of the size and luxuriance as exhibited by the older basalt ; in fact, the boundaries of the newer basaltic sheets and streams for instance, with the silurian are very frequently delineated by the commencement on the latter of forest, whilst clusters of trees within the lava-plains generally indicate silurian outcrops. To trace out with any claim to precision the particular portions which each of a number of volcanic hills contributed to an exten- sive lava-sheet surrounding them, is quite an impossibility, the generally even surface of the latter between the hills severally presenting no lines of demarcation or other guiding marks, and even the rock itself, of different parts of the plains or sheets, nearer the one or other of the hills, shows no serviceable distinc- tions either in structure or lithological character. These facts are substantiated by the relations of the numerous volcanic hills with intermediate lava-plains in all parts of the colony, and seem to indicate that the action, if not the origin, of the different points of eruption, within or fringing a defined lava-sheet, was contem poraneous, at least within such limits as to allow of an inter- mingling and even-spreading of the fiery molten matter. An observation of Mr. Selwyn's in this respect bearing more espe- cially upon the nature of some of the craters and points of eruption is "That certain features exhibited by some viz., that the walls of the craters are formed of stratified layers of ash, dipping outwards at a low angle seem to indicate the probability of their having been sub-aerial volcanic vents, forming low islands in the tertiary seas, under the waters of which the lava streams flowed and were consolidated." As the thickness of the basaltic sheets depends on the features of the original surface over which they spread, it varies accord- ingly, even within short distances, to a great extent. In the average it may be considered to range from a few feet up to 150 feet. There are exceptional places, however as, for instance, at Ballarat, where it exceeds 400 feet ; but this is due to the lava mass as a whole being composed of several sheets the so-called first, second, third, and even fourth rocks erupted and spread *See Mr. Selwyn's List of Craters and Volcanic Cones, "Exhibition Essay,'" 1866, p. 34. 29 over each other at different periods, probably at considerable inter- vals of time, judging from clay and silt deposits occurring between the different sheets. With regard to a great number of the gold- fields of the colony the streams of the newer basalt have performed a most important office, and our miners, early recognising its nature, have reaped its benefits for years past, and will do so, no doubt, for years to come. The office alluded to is the preservation of large patches of older auriferous drift against the denuding agencies of post-tertiary times agencies that wrought our pre- sent, some even deeper, valleys than those of former days, and which in doing so have even largely affected the tough mass of the lava itself. To this bear striking testimony the numerous larger and smaller outliers of the rock in many valleys remnants of once continuous lava-sheets with their rugged outlines and steep rocky escarpments. But it is not to the miner alone that the basaltic table-lands prove sources of wealth ; the agriculturist also, though in a widely different sense, and not so restricted to special localities as the former, derives lasting benefit from them. The decomposition of the lava the very opposite that saved for the miner yields, like the older basalts, one of the most fertile, if not the finest, soil in the colony ; a quality no doubt due to its richness in special alkaline and other salts, necessary or favour- able for the growths of cereals and generally most products of husbandry. But it is apparently not so well adapted for forest growth as the soil of the older basalt, though in many cases of bare plains and patches of this basalt land, the thinness of the soil or decomposed surface-layer, evidenced by the rocky nature of the ground, is undoubtedly the cause of the absence of trees. The colour of this soil is, like that of the older basalt, black or dark-brown, sometimes also reddish-brown to brick-red, and its thickness very variable, ranging on the plains and the tops and slopes of the hills from a few inches to seldom over 3 feet, but often reaching 8 feet and over in the flats and gullies running between the hills or cutting through high plateaux. Irregularly distributed through the soil, both of this and the older basalt, occur nodules of hard, dense basalt, with a brownish surface-crust, concretions of carbonate of lime and magnesia, various in size and shape, and, as a special feature in many places, a kind of small reddish-brown gravel, consisting of bean and kidney-shaped bodies of brown hematite. The small watercourses down the flanks of the hills show also generally titaniferous iron (menaccanite) in greater or less abundance. Beneath the fertile stratum of large portions of the plains there generally occurs a yellowish, tough, and soapy clay of variable thickness. It gradually merges down- 30 ward into the mass of the rock, and is therefore no doubt the- result of the decomposition of the lava in situ, and not as might be supposed a deposit derived from other sources. The peculiar surface-feature of the plains, the network of small, shallow inden- tations, forming waterpools in winter, is, as it seems, mainly dependent on the existence of this clay. On viewing the steep escarpments of the large plains and outliers, we observe most frequently a vertical, more or less perfectly columnar or prismatic structure, the prisms being mostly 5-sided, sometimes G-sided. This structure i.e., the vertical joints incident upon it proves often of some advantage to the miner in sinking shafts through the lava for the older gold drifts underneath. On the Kangaroo outliers, in the Loddon valley, for instance, many shafts may be seen, each of which has, as it were, been formed by the removal of one of the large lava prisms. Tabular structure is rather rare. A fine instance of it is met with in the neighbourhood of Kyneton, at the Little Coliban River. The rock shows there columnar and tabular structure combined i.e., on the large- scale it is columnar ; but each column shows a finely tabular structure by being cleavable into thin slate-like plates, generally at right angles to its main axis ; the side planes indicate this structure by parallel striations and grooves, more especially where the rock is affected by decomposition. There are many localities where a nodular, sphseroidal, or polygonal structure may be observed, and it is generally the case in these instances that the nodular masses consist of dense, dark rock, showing in section concentric bands of slightly varying texture and colour, whilst mostly a lighter, soft, or friable ferruginous mass fills the interstices between them. The origin of this structure is no doubt similar to that exhibited by the older basalt, described and explained in the foregoing. Another interesting feature not uncommon in the newer basalt of the Western District are large caves, about one of which, situated on the east bank of the Mount Emu Creek, Mr. Selwyn makes the following remarks : " It contains three large and lofty chambers, connected with each other by narrow passages. The first and largest chamber is 48 by 40 yards; the next (connected with the former by a short narrow passage), 44 by 27 yards ; and the furthest from the entrance (connected with the larger one by a narrow passage 13 yards long) is about 27 by 15 or 20 yards. Thousands of bats inhabit these caves, hanging in clusters from the roof like a swarm of bees, and on the floor are large conical mounds of a rich brown earthy matter, containing imbedded pieces of crystallized gypsum.* The deposit itself consists entirely of the excrements of the animals. The average height of the chambers is from 15 to 20 feet. No explorations have yet been made in the caves."t Mr. Apliu, formerly of the Geological Survey, explored a large cave near Gisborne in 1856 (see plan of cave on Geological sheet No. 7 N.W.), and found a large number of bones, amongst which Professor M'Coy determined, as the most interesting, remains of "Canis Dingo," or Wild Dog; " Diabolus (Sarcophilus) Ursinus," or Tasmanian Devil, of which genus no species is at present known living on the Continent of Australia ; " Dasyurus affinis" (M'Coy), new species ; " Phalangista," new species ; " Hypsiprimnus trisulcatus" (M'Coy), new species. As regards economic purposes, the newer basalt is of far greater importance than the older ; for besides yielding excellent road metal, the more compact bluish-grey kinds, commonly called "' bluestone," are duly appreciated for architectural and engi- neering purposes, as fine durable building stone, being easily dressed, and procurable in blocks of all dimensions up to 50 and more cubic feet. Flags cut from some occurring in the neighbourhood of Melbourne, and used for portions of the footpaths in the city, have also, so far as experience goes, proved excellent for the purpose. There are certain basalt occurrences namely, some of the dykes the age of which is rather doubtful. Whilst those dykes, occurring, as for instance in the Western Port District, close to or within older basalt areas, are most likely of the age of the latter, a number of dykes exist in some of our western goldfields (Sandhurst and Castlemaine) at comparatively con- siderable distances from basalt centres, and therefore no clue whatever of their age is given. Considering, however, that only the newer basalt occurs around the respective districts, the specimens from some of these dykes in the collection have provisionally been classed as belonging to it. Touching the mode of occurrence of the Sandhurst and Castlemaine dykes, which are partly much decomposed, and called " lava-streaks" by the miners, it is of special interest on account of the close association of the dykes with auriferous quartz reefs namely, they form either the hanging or foot walls of the reefs, or, in rarer instances, break through the latter from side to side, * Small crystals of the rare mineral " struvite," are also abundantly dispersed through the mass. + The deposit has since been used by the farmers of the neighbourhood to great advantage as a valuable manure. 32 faulting them more or less features which indicate that the fissures of the reefs have mostly been the lines of least resistance for their eruption. Upon the auriferous character of the reefs, they could, on account of their far more recent age, not have had any genetic influence whatever, though some miners wrongly suppose so. In case of such a dyke traversing and faulting a reef, it may, however, happen that auriferous shoots or patches being thereby severed and the severed parts dislocated a level driven in one part does, on regaining the reef beyond the dyke, not strike the corresponding part, but poor or barren quartz instead. Speaking generally of the influence which these dykes and both the older and newer basalt exerted upon the rocks they came during their eruption in close contact with, it has, if any, as far as observation extends, been of but a slight and transient character. Granite underneath basalt-covers has apparently not been affected at all ; clay deposits elsewhere of grey or yellow colour, are, under these circumstances, changed to brick-red, and have lost their original toughness ; and with regard to Silurian strata, the only, though doubtful, indication of a change is a peculiar perforated, as it were, vesicular texture of the slates and sandstones in the immediate neighbourhood of some points of eruption (Mount Consultation, Kangaroo Hill). Proceeding now to a special description of the older and newer basalts, relative to their lithological character, bearing in mind their essential mineral composition viz., " augite," " labradorite," and " titaniferous iron," we have in Victoria the three established sub-species viz., dolerite, anamesite, and basalt, besides an infinite number of varieties dependent on texture and other characters. (1.) Dolerite, Dolerite Lava. A crystalline-granular, dark and light-bluish or greenish-grey rock, in which crystals of its principal components, augite and labradorite, can be distinctly recognised by the naked eye. This species has not as yet been observed within the older basalt areas, and is also rare within those of the newer. Principal localities of occurrence are Malms- bury, Kyneton, Gisborne. (2.) Anamesite, Anamesite Lava. Of bluish or greenish, often brownish-grey or black colour, and distinctly recognisable, yet so finely crystalline-granular a texture, that the component minerals cannot be clearly distinguished without aid of the magnifying glass, and then only by their difference in colour. It is apparently the most prevailing. Its fracture is flat-conchoidal, with a glit- tering surface, and it is sometimes rendered porphyritic by crystals 33 -of hornblende and oligocla.se and grains ofolivine. With reference to the older basalt of Phillip Island and the neighbour- ing shores of the main land, of which a number of specimens are represented and placed under this head in the collection, there is some probability that it belongs to the species nepkelinite (nepheline-anamesite ; nepheline-basalt). To this supposition leads the recent discovery on the island by Mr. 0. Rule, of a finely porphyritic variety of the rock, containing, dispersed through a rather dense, black base, numerous crystals (hexagonal prisms) of nepheline, some more or less decomposed, besides large plates of black or brown mica, patches of triclinic feldspar, apparently oligoclase, crystals of black IwnUende, and large grains of tiiani- ferous iron. And what speaks further in favour of this view is the great abundance of zeolites, especially analcime and natrolite, in the rock of Phillip Island, and that the results of the analysis of specimens of non -porphyritic texture from that locality accord generally better with those given in books of nepheline basalts from foreign localities than with those made of basalts from other parts of the colony. (3.) Basalt, Basalt Lava. Dark-grey to mostly black, quite homogeneous-looking ; in fracture generally somewhat dull, though in some places (Little Coliban River, near Kyneton, Bacchus Marsh, &c.), quite of the aspect of Lydian stone. The texture of these three sub-species is in many places a thorough compact one, yet most frequently it is more or less porous and vesicular (honeycombed), the vesicles showing either, though rarely, a glassy surface inside, or being partly or wholly filled or coated with different minerals, whence results amygda- loidal texture. These accessory minerals will be described further on. In their mode of occurrence our three sub-species differ in some marked respects from those described from the basalt dis- tricts of Europe. The principal difference is, that they do not occur in distinct masses with defined outlines, as it is stated to be the case there, but form here rather irregular portions of undefi- nable size and shape, graduating one into the other, laterally as well as vertically, throughout the same sheet or stream of lava. They present in fact only, as it were, different forms and stages of mineral aggregation during the cooling of the molten matter. The same quarry yields thus frequently both anamesite and basalt, and at Malmsbury a quarry produces besides these also dolerite. As principal varieties, mostly of basalt proper, all well represented in the collection may be mentioned : (a.) Earthy Basalt, or, as it is called in France and Germany, Basalt Wacke A bluish, greyish, or brownish-black, mottled, D 34 earthy-looking, and more or less vesicular mass, with frequently embedded nodules of a denser texture, found in some places on top of the plains, and also beneath sheets of hard basalt. It sometimes encloses scales of mica, crystals of hornblende and oligoclase, and is frequently amygdaloidal, the amygdules consist- ing of various zeolites, chalcedony, green earth, calcite, aragonite, &c. Much of the older basalt of Phillip Island and the neigh- bourhood of Melbourne belongs to this variety, which in most cases represents in fact nothing else but basalt in an advanced stage of decomposition. (b.) Basalt Scoria. Of dark-brown or black colour, highly vesicular or cellular the vesicles or cells irregular in size and shape, and showing glazed walls very similar to some of the slags of iron-furnaces. It occurs in masses of irregular shape, and of all sizes, principally on the tops and slopes of the craters and points of eruption. The same is the case with (c.) Basaltic Pumice. A scoria so spongy and light that it floats on water, and might, except for its black or brownish- black colour, and absence of fibrous texture, be mistaken for true trachyte-pumice. (d .) Basaltic Ash. Earthy and compacted, ashy-grey or brown, sometimes mottled in these colours. Found near craters and points of eruption, frequently in stratified layers. The compacted kinds are in some localities (Warrnambool, Terang, &c.) advan- tageously used as building stone, being, when freshly broken, soft enough to be sawn into blocks of all sizes, but hardening con- siderably on exposure to the atmosphere. Both the older and newer basalt rocks are, as already mentioned, rich in accessory minerals, partly original, partly of secondary origin. As the most noteworthy original minerals may be men- tioned Olivine common in all our basalts, but more especially characteristic of the newer ; in fact it t is so frequent in places as quite to assume the place of an essential constituent of the rock. It is generally of an olive-green, sometimes emerald and bottle- green colour, has a glassy lustre, and appears in grains and larger and smaller nests or polygonal masses, of granular texture, up to several pounds in weight, irregularly distributed through the rock (Anakies, near Geelong, in the rim of the crater of Mount Franklin, &c.) It seems to decompose more easily than the mass of the rock, leaving behind it a reddish-brown substance, prin- cipally consisting of hydrous ferric oxide. A transformation into a reddish-brown micaceous mineral (rubellane ?) has also been observed in the basalt of some of the Loddon outliers. Hornblende. Of a shiny pitch-black colour, often in perfect 35 prismatic crystals up to an inch in length, and |^-inch thick ; is tolerably frequent in the older basalt of Phillip Island, and occurs in some of the newer basalt areas in very great abundance ; for instance, at the Anakies, where the centre one of these three points of eruption is literally strewn over with crystalline pieces and more or less perfect crystals of the mineral. Oligoclase. Pretty abundant in the older basalt of Phillip Island, and more especially in the rock of all crater hills and points of eruption of the newer basalt (Mount Franklin, Mount Elephant, Anakies, about 12 chains north of point loJiere the road from Eagle Tavern to Muckleford passes a small basaltic outlier. Geological ^ sheet 15 N.E. 201. ANAMESITE PORPHYRY. Very finely-granular, apparently dense and compact, black base, impregnated with crystals of hornblende and grains of olivine. From a dyke adjoining tlie Eureka Reef, Castlemaine. Note. In some parts of this dyke there occur also large plates (up to 1 inch in diameter) of brownish-black mica. The dyke has apparently exercised neither a disturbing nor a metamorphosing influence upon the reef and adjoining silurian strata. 202. BASALT LAVA. Apparently quite dense and compact ; affects strongly the magnetic needle. (See specimen No. 189). Magnet Hill, Baynton's Station. Geological % slteet 51 S. W. 203. BASALT LAVA. Dense and compact, in places slightly vesicular ; mottled brownish-red and black. Mount Consultation. Geological |- sheet 15 N.E. 204. BASALT LAVA. Quite dense and homogeneous, resem- bling Lydiari stone ; rendered porphyritic by small grains of olivine and feldspar ; slightly vesicular, the vesicles strongly compressed in one and the same direction. Little Coliban River > near Kyneton. Geological | sheet 9 S.E. Note. A very similar variety of basalt occurs also in the neighbourhood of Bacchus- Marsh. This rock was used by the natives for fashioning, spear-heads, and in sharp-edged fragments for cutting purposes,, 41 skinning native animals, ' i i 8 e* IN O 00 COININI-- OOOO frl i 1 O .Of5 i-H * cocbo : U5iibt5'--i : O CO * ' rH +3 1 * * ! -r 1^ t^ i; 14 O t C^l . O W CO .... oo co ib : o S IN : : : : to s^i I-H +3 O o o I-H . CO GO C5 I C^ O> i-^ O5 1 I * O^ c^ CO CO i-H tot- oo * o co * oo -icq . O i i OO -< IN .- CC 00 bocb -t-HO,b ' tOi-H g co N _eo -* o I-H o 00 o * OJ O O ts, 9* O U3 1-H I 1 O5 * -*COCO -^"COSJO CO co co i-( -J3 "^ 1 OSr-^CO Or-l i-H i-lgcO 1O o iO tj3 C 4O CO C^ i* ^- i^> tO 1-H i-H '* (N * OOOb- ..* " ' t-> ' "At CO CO I-H -** ** 8 8 TJ *-* M 03 O : :^2 M : : : : g : : : M r& ro^on iron-ore, prin- cipally the latter, abounds in irregular patches and impregnations ; but regular strong deposits worth working are, up to the present, not known in these rocks. The only metal, next to gold, found in quantity to be of commercial value is antimony. This occurs as grey sulphide, mostly converted into oxide near the surface, in strong veins and larger and smaller pockets, partly and more fre- quently associated with auriferous quartz reefs (Heathcote, Whroo, &c.) ; partly isolated (Ringwood) ; the upper silurian rocks having hitherto proved the most prolific. LOWER SILURIAN ROCKS. The series of specimens derived from this formation may all be classed as mechanically-formed rocks. They comprise conglo- merates, breccias, sandstones, quartz rocks (quartzite, Lydian- stone), shales (mudstones), and clay-slates, and are described in the order just given. CONGLOMERATES AND BRECCIAS. 316. SLATE-CONGLOMERATE. A base of fine-grained, soft, micaceous sandstone, enclosing rounded pieces of slate. Section, 50, Spring Plains. Geological % sheet, 13 N.E. 317. QUARTZITE-BRECCIA. Very fine-grained, dark sandstone- base, enclosiag larger and smaller angular fragments of very fine- granular quartzite. From a gully south of allotment 3, section A\, Maldon. 63 SANDSTONES. 318. SANDSTONE, QUARTZ-GRIT. Pretty even-sized, rather coarse and angular grains of quartz, cemented by a very small per-centage of a base of apparently feldspathic character ; in part ferruginous. Mia-mia Ranges, sections 42 and 66, M l lvor Road, Spring Plains. 319. SANDSTONE, QUARTZ-GRIT. Larger and smaller angular grains of quartz, cemented by very little feldspathic-looking base. Talbot. 320. SANDSTONE. Medium-grained; highly quartzose and hard, resembling quartzite ; the quartz grains connected by very little siliceous cement ; shows irregular red, ferruginous patches, and is in some parts gritty. Inglewood. 321. SANDSTONE. Medium-grained; highly quartzose, the quartz grains connected by but very little feldspathic-looking cement ; in parts brecciated ; might be useful as a building stone. Loddon River. 322. SANDSTONE. Rather coarse-grained, soft and feldspathic. M'Intyre. 323. SANDSTONE. Highly ferruginous, fine-grained and mica- ceous. Talbot. 324. SANDSTONE. Very similar to No. 323. Inglewood. 325. SANDSTONE. 'Very fine-grained and micaceous ; shows more or less ferruginous bands in the line of cleavage. New- stead. 326. SANDSTONE. Fine-grained, soft, and rather argillaceous ; highly ferruginous and micaceous. Loddon River. 327. SANDSTONE. Fine-grained, rather soft and argillaceous ; highly ferruginous, micaceous, and slightly porous. Talbot. 328. SANDSTONE. Fine-grained, soft, very micaceous, and feldspathic ; mottled with irregular ferruginous patches ; appears to be of somewhat metamorphic character. M'lntyre. 329. SANDSTONE, QUARTZ-GRIT. Coarse-grained and highly quartzose ; the greater portion coloured brown and red by hydrous ferric oxide, and traversed by a small quartz-vein. Kingower. 330. SANDSTONE. Rather fine-grained, ferruginous, and very micaceous ; small, roundish, lighter-coloured portions of appa- rently feldspathic and less micaceous character, irregularly dis- tributed throughout the mass, impart to the rock a mottled, conglomeratic appearance. Loddon River. 331. SANDSTONE. Medium-grained, minutely porous, and very feldspathic. M'Intyre. 64 332. SANDSTONE. Fine-grained, rather argillaceous, and slightly micaceous ; in part ferruginous. Mia-mia Ranges, sec- tions 42 and 66, Spring Plains. 333. SANDSTONE. Medium-grained, rather feldspathic and micaceous ; cleavage rather slaty. Kingower. 334. SANDSTONE. Very fine-grained and argillaceous, resemb- ling an indurated mudstone ; finely banded in two different directions ; one set of bands of a ferruginous character, impart- ing a concretionary appearance. Pyrenees. 335. SANDSTONE, QUARTZ-GRIT. Rather coarse-grained, and highly quartzose ; cleavage pretty even and regular. Stony Creek Reservoir, Geelong Waterworks. 336. SANDSTONE. Coarse-grained, highly quartzose, and tra- versed by quartz-veins ; resembles quartzite, but shows a cement- ing medium. Brisbane Ranges, near Geelong. 337. SANDSTONE. Medium-grained, soft, rather feldspathic, and slightly micaceous. M'Intyre. 338. SANDSTONE. Very fine-grained and tough ; siliceous, and minutely micaceous. Loddon River. 339. SANDSTONE. Very similar in character to foregoing; shows faint ferruginous bands. From between M'lvor and Sandhurst. 340. SANDSTONE. Medium-grained, rather micaceous, and slightly feldspathic ; in part ferruginous. Ooliban River. 341. SANDSTONE. Very fine-grained, micaceous, and slaty ; might be called a " slaty sandstone." Mount Franklin 342. SANDSTONE. Medium-grained, and rather micaceous ; shows very regular ferruginous lines and bands, which impart to it a concretionary appearance. Bendigo. 343. SANDSTONE. Medium-grained, pretty tough, very quartzose, and slightly micaceous ; might be useful as a building stone. From between M'lvor and Sandhurst. 344. SANDSTONE. Very fine-grained, argillaceous, and slightly micaceous ; full of impressions of fossil plants (fucoids ?). Kingower. 345. SANDSTONE. Very fine-grained, argillaceous, and slightly micaceous ; texture slaty. Swiper's Reef, Maldon. 346. SANDSTONE. Fine-grained, rather soft, and slightly micaceous ; cleavage flagstone-like. Maryborough. 347. SANDSTONE. Rather soft, and very micaceous ; fine- grained, and somewhat argillaceous. From near Bacchus Marsh. 348. SANDSTONE, FLAGSTONE. Medium-grained, quartzose, and slightly micaceous ; very thin-bedded, and of the character of a flagstone. Redesdale, Campaspe River, section 40. 65 QUARTZ ROCKS. 349. QUARTZITE, QUARTZ ROCK. Coarsely crystalline-granu' lar; in parts of a gritty texture; modification of rock No. 318. Mia-mia Manges, sections 42 and 66 ; M'lvor-road, Spring Plains. 350. QUARTZITE, QUARTZ ROCK. Coarsely crystalline-granu- lar. Ingleivood . 351. QUARTZITE, QUARTZ ROCK. Similar to No. 350, but a little more ferruginous, and, in consequence, showing some varia- tion in colour. Inglewood. 352. QUARTZITE, QUARTZ ROCK. Very finely crystalline- granular ; apparently quite dense and hornstone-like ; might furnish good grinding stones. Top of spur close to north-east corner of Mount Tarrangower Tunnelling Company's lease. 353. QUARTZITE, QUARTZ ROCK. Rather coarsely crystalline- granular, ferruginous, and in parts of brecciated appearance. Inglewood. 354. LYDIAN-STONE, LYDITE (Siliceous Slate, Kieselschiefer.) Irregularly traversed by a network of very fine quartz-veins, and more or less affected by decomposition. Loddon River, near Maldon. 355. LYDIAN-STONE, LYDITE (Siliceous Slate, Kieselschiefer.) Traversed by a network of very fine, more or less ferruginous, quartz-veins. A ra rat. 356. LYDIAN-STONE, LYDITE (Siliceous Slate, Kieselschiefer.) Shows a kind of rude prismatic structure. Loddon River, near Maldon. SHALES. MUDSTONES. The term Mudstone, introduced into science by Sir Roderick Murchison, is especially applicable to a kind of rock holding an intermediate position between very fine-grained, soft sandstone and soft shale, and which is very prevalent on many of our goldfields. Whilst, on the one hand, it is not firm enough and too fissile to be termed a sandstone, it is yet too arenaceous though very minutely so to be properly called a shale. It adheres strongly to the tongue, gives an earthy odour on being breathed upon, and falls in water, or on exposure to the atmosphere, more or less quickly, to a muddy non-plastic mass. It is, in fact, a stratified, somewhat indurated, mud, composed of lavigated sandstone, shale, 66 and clay-slate material, and showing generally a well-developed slaty or fissile texture. Its prevailing colour is mostly white or yellowish- white ; but darker shades of yellow, brown, red, and bluish-black, the former from admixture of hydrous ferric oxide, the latter from that of carbonaceous matter, are also not rare. A banded or mottled appearance in all the above shades of colour is not unfrequently met with. The term " pipeclay," as used by our alluvial miners in the phrases, " the washdirt rests on pipe- clay/' "driving in the pipeclay bottom," &c., refers in most instances to the generally softer or friable basset edges of the beds of this rock. 357. MUDSTONE. Texture imperfectly slaty ; highly argil- laceous, soft, and minutely mottled by ferruginous and dendritic m arkings. Bendigo. 358. MUDSTONE. Argillaceous, somewhat indurated, and irregularly traversed by red ferruginous bands, causing a concre- tionary appearance ; texture imperfectly slaty. Bendigo. 359. MUDSTONE. The same in character as No. 358. Bendigo. 360. MUDSTONE. A soft white portion in contact with a more indurated, mottled, ferruginous one ; texture imperfectly slaty. Bendigo. 361. MUDSTONE. Very soft and less argillaceous than fore- going specimens ; texture perfectly slaty ; approaching fissile. Pyrenees. 362. MUDSTONE. Very soft and friable, and marked with extreme regularity by parallel greyish-white and greyish-black bands. Bendigo. 363. MUDSTONE. Somewhat indurated, rather argillaceous, and showing pretty regular, parallel, greyish-white, grey, and narrow purple-coloured bands ; texture imperfectly slaty. Ingle- ivood. 364. MUDSTONE. Kather argillaceous, and showing pretty regular parallel, faintly-brown, ferruginous bands ; texture thin- slaty. Bendigo. 365. MUDSTONE. Slightly arenaceous, soft, apparently felds- pathic or like impure kaoline ; resembles decomposed elvan- dykestone. Swiper's Reef, Maldon. 366. MUDSTONE. Very soft and arenaceous. Bendigo. 367. MUDSTONE. Kather indurated and arenaceous (sand- stone-like), and densely marked by pretty regular, parallel, ferruginous bands. Inglewood. 368. MUDSTONE. Strongly indurated, arenaceous, slightly micaceous, and densely filled with ferruginous, concretionary, 67 stalk-like bodies, arranged in an imperfectly-radiating manner, which imparts to the design the appearance of coralline structure. Loddon River. 369. MUDSTONE. Argillaceous, somewhat indurated, and traversed irregularly by faint, brown, ferruginous bands ; texture slaty. Dunolly. 370. MUDSTONE. Very soft and friable ; texture slaty ; shows polished-looking slate-like faces. Lord Malmsbury Com- pany's Claim, near Malmsbury. 371. MUDSTONE. Rather indurated, argillaceous, of mottled appearance, and densely filled with small, roundish, concre- tionary, ferruginous bodies or granules, imparting to it the character of being metamorphosed ; texture slaty. Pyrenees. 372. MUDSTONE. Rather indurated and slightly micaceous, traversed very regularly by parallel, ferruginous bands. Welsh- man's Reef, Sandy Creek, near Maldon. CLAY-SLATES. 373. CLAY-SLATE. Fissile, rather soft, and shows a faint satiny lustre. Red Jacket Claim, Ballarat. 374. CLAY-SLATE. Useful for roofing purposes ; its fine dark purple colour renders it similar to the Welsh slates. Bendigo. 375. CLAY-SLATE. Thick-bedded and micaceous ; cleavage very uneven ; much traversed by joints ; has the character of a strongly indurated shale. Moorabool River, between Steiglitz and Meredith. 376. CLAY-SLATE. Cleavage tolerably perfect; rather soft, and full of ferruginous oval concretions of pretty uniform size, which much resemble fossils, and are perhaps caused by meta- morphic action. Kingoiver. 377. CLAY-SLATE. Cleavage pretty regular and even ; rather soft, and regularly and delicately banded ; contains embedded cubical crystals of iron pyrites. Bendigo. . 378. CLAY-SLATE. Similar to No. 377. Bendigo. 379. CLAY-SLATE. Cleavage even and perfect; well appli- cable for roofing purposes. Slate quarries, Meredith. 380. CLAY-SLATE. Cleavage rather uneven; apparently thick- bedded ; slightly concretionary, and in cross-fracture micaceous ; has a somewhat metamorphic aspect. Maryborough. 381. CLAY-SLATE. Rather soft and dull earthy; cleavage F2 68 pretty regular ; full of impressions of various forms of grapto lites. Lancefield, county of Bourke. Geological ^ sheet 5 /S.. 382. CLAY-SLATE. Same as N"o. 381 ; cleavage more perfect. Lancefield, county of Bourke. Geological sheet 5 S.E. 383. CLAY-SLATE. Cleavage well-developed, and cleavage- planes tolerably even ; looks suitable for roofing purposes, but is too soft. Bendigo. 384. CLAY-SLATE. Thick-bedded and somewhat arenaceous, enclosing apparently some bituminous or carbonaceous matter ; cleavage very irregular and uneven ; resembling an indurated mudstone. Loddon River. 385. CLAY-SLATE. Cleavage imperfect and uneven; rather soft ; not applicable for roofing purposes. Bendigo. 386. CLAY-SLATE. Rather tough and hard ; cleavage some- what uneven, but might be suitable for roofing purposes. Bendigo. 387. CLAY-SLATE. Thick-bedded; cleavage uneven and im- perfect ; slightly arenaceous, and contains some carbonaceous matter ; full of numerous species of graptolites. Near diorite- dyke, Tarilta. Geological | sheet 15 N.E. 388. CLAY-SLATE. Rather soft, and cleavage pretty even ; might be used for roofing purposes. Moorabool Riter, between Steiglitz and Meredith. 389. CLAY-SLATE. Rather soft, and cleaves unevenly. Yan- doit. 390. CLAY-SLATE. Soft and friable ; somewhat argillaceous and fissile ; has the character of a slaty shale ; shows on the face of a joint small patches of " blue carbonate of copper." Lerder- derg River. 391. CLAY-SLATE. Soft and friable, and rather fissile, resem- bling slaty shale. Yandoit. 392. CLAY-SLATE. Cleaves pretty evenly, but is too soft for roofing purposes. Bendigo. 393. CLAY-SLATE. Very ferruginous, and hard enough for roofing purposes, but cleaves unevenly, and is apparently much jointed. Bendigo. 394. CLAY-SLATE. Cleavage imperfect, and planes of earthy, dull aspect ; ferruginous, and full of various forms of grapto- lites. Section 29 Spring Plains. Geological sheet 13 N.E. 395. CLAY-SLATE. Hard, micaceous, and slightly arenaceous; cleaves unevenly, and shows ferruginous bands of various shades of brown colour. Talbot. 396. CLAY-SLATE. Much jointed, rather hard, and cleavage very uneven. From near Newstead. 69 397. CLAY-SLATE. Rather thick-bedded, soft, argillaceous and slightly micaceous. Section 26, Spring Plains, Stone- Jug Greek. 398. CLAY-SLATE. Rather soft ; argillaceous and minutely porous ; cleavage pretty perfect and even ; slightly fissile ; full of various forms of graptolites. Shepherd's Claim, Christmas Reef, Bendigo. 399. CLAY-SLATE. Fissile, quartzose and micaceous ; ferrugin- ous bands produce a concretionary appearance. Dunolly, 400. CLAY-SLATE. Soft, and highly argillaceous, in part quite steatitic ; red ferruginous bands produce a peculiar concretionary aspect ; cleaves evenly, but rock apparently much jointed. Town Reef, Castlemaine. 401. CLAY-SLATE. Hard, ferruginous, and cleavage extremely uneven ; traversed by ferruginous quartz-veins. From close to a quartz reef, Talbot. 402. CLAY-SLATE, BLACK LODE-SLATE. Fine-grained grey sandstone (V) in contact with the slate ; the former rather concre- tionary, the latter slightly micaceous ; both impregnated with iron pyrites, and traversed by quartz- veins. From, a quartz reef, Clunes. 403. CLAY-SLATE, LODE-SLATE, GANGTJE-SLATE. Fissile, but cleaves very irregularly ; shows a weak satiny lustre ; in parts impregnated with iron pyrites, and traversed by quartz- veins From a quartz reej, Clunes. 404. CLAY-SLATE, LODE-SLATE, GANGUE-SLATE. Similar to foregoing, but slate black and carbonaceous ; impregnated with iron pyrites, and traversed by quartz- veins. From a quartz reef, Clunes. UPPER SILURIAN ROCKS. MECHANICALLY-FORMED ROCKS. CONGLOMERATES AND BRECCIAS. 405. CONGLOMERATE. Fine-grained, quartzose, more or less ferruginous sandstone base, enclosing small rounded pebbles of quartz and different rocks, and densely filled with casts of fossils. Goulburn River. 406. CONGLOMERATE. Same as foregoing. Goulburn River. 407. CONGLOMERATE. Smaller and larger rounded pebbles of quartz, slate, dykestone, &c., cemented by black, carbonaceous 70 lode-slate, strongly impregnated with iron pyrites. This rock forms the footwall of the Diamond Eeef, which runs alongside of a feldspathic aphanite dyke. Taken at a depth of nearly 250 feet from the surface in the Union Company's mine. Owes its origin most probably to friction of the wall and the reef. Diamond Creek. 408. CONGLOMERATE. Same as foregoing. Union Com- pany's mine, Diamond Creek. 409. CONGLOMERATE. Dark-grey, fine-grained, quartzose, sandstone base, cementing small, pretty even-sized, rounded pebbles of quartz ; encloses casts of fossils. From a boulder in Goulburn River, below Maori Creek. 410. BRECCIA, HORNSTONE-BRECCIA. Very fine-granular, apparently dense, black quartzite or hornstone base, strongly impregnated with iron pyrites, and enclosing angular, or but slightly rounded, larger and smaller fragments of quartz and feldspar, which impart to the rock in parts quite a porphyritic character. Duncan's tin-lode, Melbourne road, Beechworth.~ :: ' 411. BRECCIA, HORNSTONE-BRECCIA, GRANITE- BRECCIA. Dense, dark, hornstone base, enclosing angular fragments of granite and feldspar, besides fragments and crystals of quartz, dark violet-coloured fluorspar, and sparingly cassiterite ; looks in parts like a porphyry. Duncan's tin-lode, Melbourne road, JBeechworth.* 412. BRECCIA, GRANITE-BRECCIA. Irregular mixture of angular fragments of granite, quartz, quartzite, hornstone, and feldspar, traversed by irregular small veins, and enclosing patches of fluorspar, and sparingly impregnated with crystalline grains of cassiterite and iron pyrites. Duncan's tin-lode, Melbourne road, Beechworth* 'Concerning the age of the rocks in the Beechworth district, whether upper or lower Silurian, there exists still some uncertainty, on account of the non- discovery as yet of direct palseontological evidence. However, as these rocks are nearer related in geographical position to the upper than to the lower Silurian, and, moreover, as indirect fossil evidence exists in patches of boulder conglomerate (upper palaeozoic?) in the Eldorado valley, containing pebbles and boulders of highly fossiliferous upper silurian sandstone, which, on account of the softness of the rock, could not have travelled from afar, the specimens in the collection have provisionally been classed as of upper silurian age. 71 SANDSTONES. 413. SANDSTONE, QUARTZ-GRIT. Very coarse-grained, gritty, ferruginous sandstone, with occasional large rounded pebbles of quartz, densely filled with casts of fossils Forms the walls of the Waverley Reef, Wood's Point. 414. SANDSTONE. Fine-grained, micaceous, rather soft ; encloses casts of fossils. Heathcote. 416. SANDSTONE. Fine-grained, hard, quartzose sandstone, very micaceous upon the cleavage planes ; shows irregular ferruginous markings. Section 50, Spring Plains, near Yan Yean. 417. SANDSTONE. Fine-grained, rather soft, argillaceous, and much jointed. Yan Yean, Plenty River. 418. SANDSTONE. Medium-grained, very quartzose, highly fossiliferous. Range east of township of Heathcote. 419. SANDSTONE. Medium-grained, rather quartzose, slightly micaceous ; appears to be too much jointed to render it applic- able for building purposes. Yan Yean, Plenty River. 420. SANDSTONE. Fine-grained, rather argillaceous and highly ferruginous ; contains casts of fossils. Heathcote. 421. SANDSTONE. Same as No. 420. HeatJicote. 422. SANDSTONE. Fine-grained, quartzose and ferruginous ; fossiliferous. Heathcote. 423. SANDSTONE. Medium fine-grained, very quartzose, slightly ferruginous . Heathcote. 424. SANDSTONE. Very fine-grained and rather argillaceous ; slightly micaceous, and in part ferruginous ; densely filled with casts of fossils. Range north-east of Kilmore. 425. SANDSTONE. Fine-grained, rather argillaceous and mica- ceous; thin-bedded, with slate-like cleavage; full of fossils. Moonee Ponds Greek. 426. SANDSTONE. Fine-grained and somewhat argillaceous ;. thin-bedded, jointed, and highly micaceous upon the bedding planes. Yan Yean, Plenty River. 427. SANDSTONE. Fine-grained, ferruginous and argillaceous ;. densely filled with casts of fossils. From near Waverley Reef > Wood's Point. QUARTZ ROCKS. 428. QUARTZITE, QUARTZ ROCK. Very finely crystalline- granular, tough and hard, slightly impregnated with iron pyrites, and traversed by quartz-veins ; rather calcareous, and resembling 72 crystalline limestone ; shows partings of black carbonaceous slate. Thomson River Copper Mine, near Walhalla. 429. QUARTZITE, QUARTZ ROCK. Same as No. 428. Thom- son River Copper Mine, near Walhalla. 430. QUARTZITE, QUARTZ ROCK. Finely crystalline- granular, in parts slightly gritty and conglomeratic ; highly ferruginous, and very hard and tough. From between M'lvor and Sandhurst. 431. QUARTZITE, QUARTZ ROCK. Finely crystalline-granular, and full of casts of fossils. Goulburn River. 432. QUARTZITE, QUARTZ ROCK. Same as 'No. 431. Goulburn River. SHALES. 433. SHALE. Argillaceous and slightly micaceous, apparently thick-bedded; cleavage quite imperfect. Upper Tarra. 434. SHALE. Highly indurated and argillaceous ; in part very micaceous, ferruginous, and irregularly traversed by ferru- ginous seams ; cleavage very uneven and imperfect. Quarry near Botanical Gardens, Melbourne. 435. SHALE. Highly argillaceous and rather micaceous ; cleavage somewhat slaty, but very uneven. Upper Tarra. 436. SHALE. Indurated, argillaceous and rather slaty, slightly micaceous ; much jointed ; cleavage irregular ; full of casts of fossils. Upper Yarra. 437. SHALE. Same as No. 436. Upper Yarra. CLAY-SLATES. 438. CLAY-SLATE. Traversed by hard, fine-granular quartzoze bands; cleavage very uneven; slightly concretionary. Wal- halla mine, Walhalla, Stringer's Creek. 439. CLAY-SLATE. Cleavage pretty even and regular, coin- ciding with bedding planes ; might be useful for roofing pur- poses. Walhalla mine, Walhalla, Stringer's Greek. 440. CLAY-SLATE. Cleavage imperfect, coinciding with bedding planes ; not applicable for roofing purposes. Mouth of tunnel of Great Extended Walhalla Company, Thomson's River, near Walhalla. 441. CLAY-SLATE. Highly micaceous and somewhat arena- 73 ceous; cleavage uneven; encloses remains of fossil plants (fucoids) ; occurs interstratified with No. 440. Mouth of tunnel of Great Extended Walhalla Company, T/iomson's River, near Walhalla. 442. CLAY-SLATE. Very argillaceous, and apparently rather thick-bedded ; cleavage very uneven ; full of fossil plant impres- sions ; approaches an indurated shale in character. Morris's antimony claim, east of Heatlicote. 443. CLAY-SLATE. Similar to No. 442, but not so rich in fossil-plant impressions. Wall-rock of the Diamond Reef, near Nillumbick. 444. CLAY-SLATE. Somewhat siliceous, and harder and of darker colour than No. 443. Wall-rock of the Diamond Reef, near Nillumbick. 445. CLAY-SLATE. Thick-bedded, micaceous, and slightly arenaceous ; cleavage planes mottled and uneven. Upper Yarra. 446. CLAY-SLATE. Same as No. 445. Upper Yarra. UPPER PALAEOZOIC ROCKS. DEVONIAN, CARBONIFEROUS, AND PERMIAN. The specimens placed under this head are collected from strata that occur in widely-separated, more or less isolated, patches of larger and smaller area, over a range of country extending from the Glenelg near the west, to the Snowy River near the east boundary of the colony. From Mr. Selwyn's observations,* to whom the above classification is due, we learn about these deposits as follows : The grouping . of the several patches of strata as " upper palaeozoic," must be considered to a certain extent as provisional, as, though some are certainly referable to that period, others may have eventually to be classed as " lower mesozoic." So much is certain, that they are intermediate in age between the upper silurian on the one hand and the mesozoic " carbonaceous" or coal-bearing rocks on the other, which latter almost certainly rest on them under the greater part of the Gippsland plains from Hayfield and Mewburn Park to Rosedale, Sale, Stratford, Lake Wellington, &c. They are chiefly developed to the westward in the Grampians, and in the Sierra or Victoria and Dundas Ranges, and to the eastward in a country extending from a little north of Port Albert through Ben Cruachan and * " Notes on the Physical Geography, Geology, and Mineralogy of Victoria." Intercolonial Exhibition Essays, 1866. 74 Mount Wellington, whence they probably also extend in outlying patches across the Great Dividing Range to the valley of the Devil's River. Other smaller patches or "outliers" occur throughout the intervening central portion of the colony at Bacchus Marsh and Ballan ; on the eastern part of the Mount Macedon Kanges ; on the Coliban, near Kyneton ; on the Wild Duck Creek, near Heathcote ; and on tributaries of the Upper Goulburn, near Mansfield ; also at Mount Tambo, on the head waters of the Mitta Mitta. The lithological character of the different beds, and the general physical aspect and prevailing colour of the formation, bear a very close resemblance to those of the lower carboniferous and Devonian formations of Britain . In the western part of the colony, a thickness of upwards of 2000 feet is exposed in the precipitous escarpments of the Grampians, Mount Sturgeon, Mount Abrupt, and the eastern face of the Victoria Ranges. The lithological character of the series, as exhibited in the Grampians, is strictly arenaceous massive thick-bedded sandstones with bands of sandy flags, but no slaty or shaly beds. Considerable variations occur in texture and composition, from very hard siliceous grit and quartz rocks, with included pebbles of white quartz (as at Mount Talbot, Mount Arapiles, and the Black Range), to hard and soft, fine-grained freestones. The prevailing colours are shades of whitish-brown, reddish-brown, and white ; rarely brick-red. Much cross stratification or false-bedding is observ- able ; but the whole formation has a general westerly dip, at rather low angles, giving a gentle slope to the faces of the hills in that direction, whilst to the eastward the beds terminate abruptly in bold rocky escarpments, and almost vertical cliffs, several hundred feet in height. In the Dundas and Black Ranges the dip of the beds is reversed, or to the eastward, indicating a synclinal axis between those hills and the Gram- pians, Sierra, and Victoria Ranges. In some places the beds are seen to rest directly on granite, whilst in others they rest on the upturned and denuded edges of the silurian strata. At Mount Sturgeon, the southern end of the Grampians, several quarries have been opened, from which " freestone " of excellent quality can be obtained in unlimited quantity. The cost of transport, however, from such a remote district, prevents its use in Mel- bourne, although in many respects it is perhaps the best freestone yet found in Victoria. At one time, large quantities of stone were raised from similar beds about twenty-five miles west of Melbourne, near Bacchus Marsh, and used in the construction of several public buildings in Melbourne ; but various reasons pre- 75 vented its further use. (See note to specimen No. 456.) In several of the localities above enumerated, thick masses of con- glomerate are associated with the sandstone. They occur generally towards the base of the series, and are composed of a very irregular aggregation of rounded pebbles, and occasionally angular, or sub-angular, fragments of all sizes of granite, green- stone (diorite), various porphyrites, hard slates, gritty sandstone, grey quartz rock, and quartz. These pebbles or fragments are imbedded either in a soft, sometimes earthy, mass, showing little or no trace of stratification, as at Darley, near Bacchus Marsh ; or are interspersed in a thinly-stratified sandy shale, as at the point where the road from Sandhurst to Lancefield crosses the Wild-duck Creek. (See specimen 447.) They more commonly occur in hard cemented masses, as on the Mount Macedon " con- glomerate range ;" in the valley of the Howqua, near Mansfield ; at Ben Cruachan and the Avon River Ranges, Gippsland ; on the Macalister, near Mewburn Park and Mount Tambo. From Mount Macedon eastwards, and especially near Mansfield and in the Gippsland localities, greater variations in the general character, colour, and composition of the beds occur than is observed in the more western outcrops ; and I am inclined to think that the Bacchus Marsh, Ballan, and Grampian beds are newer than any we have in the eastern districts. A few extracts from notes made at some of the localities named will afford the best idea of their general character : Mount Tambo, about 3800 feet above the sea, shows thick masses of purple quartzose grit, coarse conglomerate, and soft, fine-grained, yellowish, micaceous shales, with numerous indistinct impressions of plants; dip south 15 west at 50 to 60. The base of Mount Tambo, on the north side, consists of gneissose schist and feldspar porphyry. At the Avon River, above junction of Valentia Creek, we find yellow and brownish-red, coarse-grained sandstones, and mica- ceous freestones with numerous impressions of plants. Very good specimens of lepidodendron are found here ; also other vegetable impressions not sufficiently distinct to be determined. These plant beds are underlaid in this locality by a great thickness of purple-red, rubbly, and nodular shales, interstra- tified with hard, fine-grained, purple-red or light-claret-coloured sandstones. The faces of the sandy beds are almost always covered with mica in large scales. Near Mansfield, to the north- west, at Mount Battery, precisely similar beds with impressions of plants occur, also underlaid, as on the Avon, by thick beds of coarse conglomerate. The average dip of the beds is generally under 30, and in some places, as at Guana and Moitun Creek, 76 where they are exposed in cliffs 250 to 300 feet in height, they are quite horizontal. On the Freestone Creek, near Bushy Park, whitish-brown freestone, with purple and dark-blue and brown micaceous shales, were observed ; and, associated with them, greenish-coloured rubbly, calcareous bands, closely resembling the " cornstones" of the old red sandstone series, to which also the whole formation bears a striking resemblance. With the excep- tion of traces of copper in the shales on the Devil's Eiver, near Mansfield, and of thin veins of micaceous iron-ore in the sand- stones of the Grampians, no minerals of economic value have as yet been found in any part of the series of these rocks, neither do they present indications of quartz reefs or other mineral lodes. The occurrence of gold in the conglomerates derived from the quartz-veins of the silurian rocks on which they are deposited is an interesting and still undetermined question. Several analyses have been made of quartz taken from the conglomerates in one instance from a place on the Werribee, where the quartz had clearly been derived from the denuded surface of a silurian quartz vein ; but neither in this, nor in any other instance, was even a trace of gold detected, and, as might be expected, no alluvial or other gold deposits have been discovered within any area of Victoria exclusively occupied by these rocks. Mount Tambo, Avon River (Gippsland), Mansfield, and Bacchus Marsh are the only localities where fossil plants have yet been found, and in two only of these, viz., Avon River and Bacchus Marsh, are the specimens sufficiently perfect to be clearly identified ; from the former lepidodendron, and from the latter cyclopteris or gangemopteris longifolius (McCoy), the former certainly palaeozoic, the latter probably triassic or lower mesozoic. No fossils of any kind have been found in the Grampian beds, and not a trace of fossil animals in any part of the arenaceous and argillaceous parts of the series. This apparent scarcity of fossils may, however, in a great measure be due to the hitherto but cursory and partial examination these strata have been subjected to. The position in the series of the upper palaeozoic fossilifer- ous limestone, which occurs in isolated patches for instance, at Buchan (where it contains galena deposits), Bindi, &c,, in eastern Gippsland has not been satisfactorily determined. The small patch near Bindi would, however, appear to be above the plant- bearing sandstones and conglomerates of Mount Tambo, and, if so, would indicate that the latter are older than the true European palaeozoic coal-measures, which, so far as is known at present, do not exist in Victoria. 77 MECHANICALLY-FORMED ROCKS. CONGLOMERATES, BRECCIAS, &c. 447. CONGLOMERATE, PUDDINGSTONE. Larger and smaller water worn pebbles of quartz, sandstone, slate, quartzite, &c., inter- mixed with sand, and rather loosely cemented by a small per- centage of argillaceous paste; resembles compacted shingle. Wild-duck Creek, near Heathcote. 448. CONGLOMERATE, PUDDINGSTONE. More or less water- worn pebbles and grains of quartz, quartzite, slate, sandstone, &c., embedded in an argillaceous paste. Mia-mia, parish of Spring- Plains. 449. CONGLOMERATE, PUDDINGSTONE. Same as No. 448. Mia-mia, parish of Spring Plains. 450. CONGLOMERATE. Larger and smaller, more or less water- worn, pebbles and grains of sandstone, quartz, quartzite, &c., rather sparingly distributed through an argillaceous paste. Mia- mia, parish oj' Spring Plains. 451. CONGLOMERATE. Same as No. 450. Mia-mia, parish of Spring Plains. SANDSTONES. 452. SANDSTONE. Coarse-grained, rather friable, argillaceous slightly feldspathic sandstone, rendered gritty by larger grains of quartz, quartzite, slate, &c. Wild-duck Creek, Heathcote. 453. SANDSTONE. Rather fine-grained and ferruginous; too- soft for building purposes. Wild-duck Creek, Heathcote. Mr. Norman Taylor's Geological Note. The formation from which specimens Nos. 448, 449, 450, and 451 are taken, is an extension of the beds occurring at the Wild-duck Creek, exem- plified by specimens Nos. 447, 452, and 453, and forms proba- bly either the base of the carbonaceous series or the top of the upper palaeozoic beds ; but fossils not having been discovered, its exact age is somewhat doubtful. The conglomerate specimens (Nos. 448, 449, 450, 451) were taken from a hole sunk by the Geological Survey party at the Mia-mia on the Heathcote road, no bottom being found at a depth of 30 feet. The con- glomerate consists of a bluish-grey, very hard mud-cement, some- times having a slight yellow tinge, and is in places interstratified with veins of an aluminous mineral. It becomes much lighter 78 in colour by exposure, and soon crumbles to pieces. The pebbles contained in it vary much in size, and consist of granites of various colours and textures, principally red and white, porphyries, indurated sandstones, quartz, white, red, and blue ; flinty quartzites, and a peculiar flint-coloured rock with red feldspar crystals, weathering white. From one of the constituents of this latter rock having externally decomposed in horizontal lines, it has the appearance at first sight of gneiss. This deposit forms a very good red soil, but is boggy and rotten in winter. At this locality it is very thin, the silurian rocks cropping up in the almost flat gullies. On the Wild-duck Creek, however, a fine section in many places at least 90 feet above the level of the creek may be seen under Robertson's Station. The conglomerate is here capped by a yellowish grit (No. 452), and rests on yellow sandstone (No. 453), forming large open downs. About two miles higher up the Wild-duck Creek, near Wilton's Station, the beds may be seen filling up depressions in the upturned edges of the lower silurian beds. 454. SANDSTONE. Rather coarse-grained, feldspathic, and minutely porous; applicable for building purposes. Werribee, near Ballan. Geological ^ sheet 11 S. W. 455. SANDSTONE. Medium-grained, rather argillaceous, and very slightly micaceous ; shows fossil-plant impressions ; useful as a building stone. Werribee, half-mile south of East Ballan. 456. SANDSTONE. Fine-grained and somewhat argillaceous ; middling hard ; occurs in thick beds, and forms a tolerably good building stone. Darley quarry, near Bacchus Marsh. Mr. Selwyn's Geological Note. The quarries in this sandstone, near Bacchus Marsh, were opened in 1862, and a considerable quantity of the stone was sent to Melbourne, and used in the con- struction of the Treasury, the Parliamentary Library, and the Custom House. It has not since been used in Melbourne. When opening the quarries, the beds were found to be very variable in composition, and so full of joints as to make it both difficult and costly to obtain the stone in quantity of the uniform texture and quality essential in large buildings. It constitutes, however, a useful building stone for local purposes, or where small quantities only are required. The buildings above referred to (especially the Parliamentary Library) do not present favourable evidence as regards its durability when exposed to the atmosphere of the city. Some of the beds are full of fossil-plant remains, of which gan- gemopteris longifolius (McCoy) is the most abundant species ; other beds afford excellent grindstones. 457. SANDSTONE. Fine-grained, argillaceous and somewhat 79 micaceous ; occurs in thick beds, and does not^form a good build- ing stone, though having the appearance of one, being too soft and easily affected by atmospheric influence. Johnson's quarry at the Caliban River, near Kyneton. 458. SANDSTONE. Medium-grained and quartzose, but too soft and friable for building purposes ; traversed by thin ferruginous bands. Johnson's quarry at the Coliban River, near Kyneton. Geological Note. The sandstone represented by specimens Nos. 457 and 458 is of white or light-yellow colour, often brown- banded, and consists of very fine quartz grains, rather loosely cemented by agillaceous matter- It overlies in very thick beds unconformably the silurian rocks, and is interstratified with thin beds of a very coarse conglomerate or puddingstone. Fossils seem to be entirely absent. The stone has been used in several buildings in Kyneton and the neighbourhood ; but though soft and easily worked, and sometimes becoming apparently harder on exposure to the atmosphere, it is very liable to exfoliate, and can also not be procured of uniform colour in large quantities. For these reasons the quarries have been abandoned. The tertiary (older pliocene) gold-bearing gravel-beds overlie this sandstone in several places, whilst basalt overlies both, and seems to have altered the sandstone at the places of contact into a hard quartzite, numbers of angular pieces of which, intermixed with such of a coarse quartz-grit, occur scattered along the respective boundaries, a specimen of the quartzite being represented further on by No. 460. QUARTZ ROCKS. 459. QUARTZITE, QQARTZ ROCK. Micro-crystalline-granular, of jaspery aspect, highly ferruginous ; shows in part a coating of pure mammillated brown iron-ore. Grampians. 460. QUARTZITE, QUARTZ ROCK. Finely crystalline-granular, traversed by faint ferruginous bands. (See Geological Note under No. 458.) Neighbourhood of Johnson's quarry at ihe Coliban River, near Kyneton. 461. LYDIAN-STONE, LYDITE (Siliceous Slate, Kieselschiefer). Highly fractured by a network of joints and fine quartz-veins, which latter impart to it in places a brecciated appearance. Mount Staveley, six miles west of Wickliffe. 80 CHEMICALLY-FORMED ROCKS. LIMESTONES. 462. LIMESTONE. Finely crystalline-granular, with occasional larger crystalline grains and small irregular veins of calcite ; fossiliferous. Mount Tambo, North Gippsland. 463. LIMESTONE. Very finely crystalline-granular, nearly dense portions intermixed with more coarsely crystalline ones. Lillydale. 464a. LIMESTONE. Very finely crystalline-granular, with seams of calcite. Buchan Lead Mine, South-east Gippsland. 4646. LIMESTONE. Same as No. 464. Buchan Lead Mine, South-east Gippsland. 465. LIMESTONE. Micro-crystalline-granular, densely filled with fossils (spirifers). Neighbourhood of Murrindal Lead Mine, Buchan, South-east Gippsland. 466. LIMESTONE. Same as No. 465. Neighbourhood of Murrindal Lead Mine,,Soutli-east Gippsland. 467. LIMESTONE. Coarsely crystalline-granular. Composition according to Mr. Newbery's analysis : Iron and alumina ... ... ... ... 2.92 Carbonate of lime ... ., 95.55 Magnesia trace Silica and insoluble matter ... ... ... ... 1-53 100-00 Burnt Creek, near Mansfield. SECONDARY OR MESOZOIC ROCKS. In the Intercolonial Exhibition Essay of 1866, and some of his reports, Mr. Selwyn makes about these rocks the following observations : They extend over an area of close upon 4000 square miles in three distinct and separate districts, viz.: Miles. Western Port to Cape Patterson, Welshpool, and the La Trobe Eiver, near Traralgon 1,751 The Gellibrand Eiver and Cape Otway to the Barrabool Hills and Indented Heads 1,882 The junction of the Wannon and Glenelg Rivers, and neighbourhood of Casterton, Digby, Merino, and Coleraine ... 349 They include all the known coal-bearing rocks of Victoria, and it is probable that these extend eastward, under a great part of 81 the Gippsland plains, south of a line drawn from near Hayfield to Lake Wellington, but cannot be seen on the surface, on account of being thickly overlaid, as at Bellarine and Queenscliff, by tertiary rocks and recent alluvial deposits. Their thickness seems to be at least 5000 feet. Very few sections have as yet been found that show clearly the relation of this " carbon- aceous" formation to the older strata on which it rests. In a few instances it is clearly seen to have been deposited on granite, the detritus of which, not much waterworn, enters largely into the composition of some of the beds. In one case, in the valley of the La Trobe River, near Traralgon, it is found resting on the upturned edges of the auriferous Silurian rocks, and the lower beds of the " carbon- aceous" formation consist of thick masses of brecciated agglo- merate of small angular fragments of rock, apparently derived from the subjacent silurian strata. A great similarity in general mineral and lithological character obtains throughout these rocks in the several districts. Alternating masses of hard and soft, thick-bedded sandstones and argillaceous shales occur in all parts of the series, and occasionally thin bands of hard, grey or brown calcareous rock are met with ; but there are no distinctive or characteristic groups of beds that would render their co-ordina- tion possible in widely-separated localities. The prevailing colour of the strata, especially of the sandy beds, is a dull greenish- grey, occasionally passing into brown. The shales are commonly dark-grey, or almost black. Not unfrequently portions of large branches or trunks of trees are met with, horizontally imbedded. The formation does not, apparently, contain any metallic minerals, except iron, in the form of concretionary nodules of clay iron-ore (carbonate of iron) and brown hematite, but these have not, as yet, been found in sufficient quantity to be economically valuable. Iron pyrites occurs also, often strongly impregnated, generally in the black shales, and it is an interesting fact that a sample of such pyrites assayed at the Geological Survey laboratory yielded at the rate of 6 dwts. 18 grs. of gold per ton. Calcite is met with both in veins and as thin coatings on the faces of the joints. The average dip of the beds does not exceed 20, and they are often horizontal over considerable areas. In the vicinity of Geelong, the sandstone has been exten- sively quarried and used in the construction of most of the larger public and private buildings in that city. The English, Scottish, and Australian Chartered Bank in Elizabeth-street, Melbourne, is also built of freestone from the same formation, quarried at Griffith's Point, on the east side of Western Port Bay. G 82 Like the upper palaeozoic freestones from Bacchus Marsh, these also are found to be locally much impregnated with saline matter, which, on exposure to the weather, effloresces on the surface of the stone, causing rapid exfoliation and decay. The character of the strata generally indicates that they have been formed in shallow water, under the influence of strong and con- stantly varying currents, giving rise to much diagonal and wedge- shaped stratification or " false" bedding. The general lithological character of the Cape Patterson beds, for instance, may be gleaned from the following brief description (report of December, 1853) : They consist of a series of thick-bedded, rather soft, coarse, and fine-grained, very feldspathic sandstones, grits and brecciated conglomerates, of various shades of brown, yellow, and greenish- grey, dependent on the state of oxidation of the iron, forming the colouring matter. These beds are apparently formed from the detritus of granite and trappean rocks, and often contain frag- ments of feldspar crystals. The weathered faces of the beds present everywhere a network of veins composed of hard, sandy ironstone, or carbonate of lime, as well as numerous large and small ferruginous, sandy nodules and concretions. These veins and nodules, being much harder than the surrounding rock, have resisted the denuding action of the atmosphere and the waves, and are now left standing out in all directions, giving the beds a very rough, uneven, and fractured appearance. In the Cape Otway District the strata show very similar characters, according to Mr. Charles Wilkinson's report of 1866. The only fossil animal yet discovered in any part of the Victorian "carbonaceous" rocks is a species of Unio (named Unio Dacombii by Pro- fessor McCoy), found in 1859, whilst sinking for coal, in the Wannon District. Specimens of Sphenopteris, Pecopteris, Zamites, and Tceniopteris, are found in the same beds, as also in all the other districts in which the coal-rocks occur. SpJicnop- teris and Tceniopteris Daintreei are, according to Mr. Charles Wilkinson, especially abundant in the Cape Otway District. The physical character of the country in which the mesozoic carbon- aceous rocks occur is very varied. In some areas there are densely timbered hills and valleys ; in others, fine undulating downs, clothed with rich grass, and scarcely any timber ; or low flat country, covered with varieties of coarse grass, heather, grass- tree, stunted gums, and clumps and patches of gum-scrub. This latter character is, however, due to the presence of overlying newer tertiary deposits, that commonly forn>a poor sandy soil. Where they are not so overlaid, the soil is generally deep and exceedingly fertile, as on the Barrabool Hills, in the valley of 83 the Wannon, and in parts of the Western Port and Cape Otway Ranges. As timber-producing districts, and in variety of vegeta- tion, the two last-named are probably unsurpassed by any in the colony. In all the areas occupied by this formation, seams of coal have been found, but they are apparently not confined to any particu- lar part of the series. The quality of the coal varies greatly. Ordinary brown coal, bright jet coal, that will not soil the fingers, and good bituminous coal, have all been observed. The " brown coal" character, is however, by far the most prevalent ; the good bituminous seams are rare, and no " anthracite" has yet been found. The most and thickest (about 4 feet) seams have been discovered in the Cape Patterson district ; but they are only of very limited extent, very variable in thickness, and more or less disturbed by basalt dykes and faults, which, combined with their unfavourable position as regards transport, precludes the possibility of their being profitably worked. If thick and exten- sive seams exist, they will have to be sought by deep sinking into those portions of the formation that are not exposed at the surface. This opinion of Mr. Selwyn's about the coal formation, expressed in a report as early as 1853, has since been sustained by the report of the Coal Commission (Messrs. R. B. Smyth, C. Hodg- kinson, and T. Couchman), and, more recently still, by the exami- nation and report of Mr. Mackenzie, the coal-viewer of New South Wales. Whether the nevertheless still actively prosecuted exploration of the less known areas and the opening of several of the larger seams some discovered since Mr. Selwyn's time will lead to favourable results, remains to be seen. The construction of the Gippsland railway, and of contemplated tramways, would, at any rate, greatly lessen the cost of transport of the mineral to Melbourne, and might thus, perhaps, render seams worth working which otherwise would have to remain neglected.* As an interesting and valuable result of recent prospecting in the carbonaceous district south of the Moe, Gippsland, deserve- mention the discovery at Stockyard Creek of richly auriferous drift and quartz reefs, in a small irregular area of silurian rocks, exposed within the carbonaceous formation, in which latter sma'l seams of coal occur in close neighbourhood to the gold-workings. * Since the foregoing was written, several promising coal-seama have beou discovered at Billy's Creek, Fiazelwood, in the Moe District, which, it is con- fidently believed by the discoverers, will pay well for working when tlju Gippsland Railway is finished. An analysis of some of the coal by Mr. Cosm > Newbery gave 63'10 per cent, of fixed carbon, 5 '90 of ash, 20 '85 per cent, of volatile matter, and 10'15 per cent, of water. 84 MECHANICALLY-FORMED ROCKS. CONGLOMERATES (PUDDINGSTONES), BRECCIAS, &c. 468. CONGLOMERATE, Puddingstone. Consists of a base of quartz-grit or small-grained quartz conglomerate, enclosing larger rounded pebbles of quartz and greenstone. Barrabool Hills, near Geelong. 469. BRECCIA. Composed principally of silicified remains of plants and carbonaceous matter, cemented by gritty sandstone. JBarrdbool Hills, near Geelong. 470. SANDSTONE-GRIT. Granitic detritus,principally composed of coarse grains of quartz, smaller ones of more or less decom- posed feldspar and little mica, rather loosely cemented by slightly ferruginous, argillaceous matter. Barrabool Hills, near Geelong. 471. SANDSTONE-GRIT. Very coarse grains of quartz, feldspar, sandstone, slate, &c., cemented by an argillaceous paste ; in parts conglomeratic, through enclosed larger rounded fragments of quartz, sandstone, &c. Barrabool Hills, near Geelong. 472. SANDSTONE. Very coarse-grained, gritty, and feldspathic; very similar to No. 471, but is harder. Barrabool Hills, near Geelong. 473. SANDSTONE. Very similar to foregoing ; coarse-grained, somewhat gritty, argillaceous and feldspathic ; encloses sparingly larger pebbles, and is interstratified with thin seams of what appears to be cemented granitic detritus. Barrabool Hills, near Geelong. 474. SANDSTONE. Rather coarse-grained, feldspathic, and minutely porous ; might be applicable as building stone. Barrabool Hills, near Geelong. Mr. Selwyn's Geological Note. The carbonaceous rocks of the Barrabool Hills (from which the foregoing specimens are taken) consist of a series of hard, thick-bedded, brown and grey sandstones, much jointed, and with thin veins of carbonate of lime. They alternate with shales and conglomerates, and have an average dip of E. 30 S., at an inclination of 1 in 4. Over the area com- prised between the village of Ceres and the municipality of New town and Chilwell, about 3000 feet of carbonaceous strata crop out at the surface ; the highest beds are found to the east and the lowest to the west. It is highly probable that this part of the series has been tested for coal in the Bellarine District, since an intermediate synclinal axis exists in the ground between Kensington and Geelong ; and the Barrabool Hill sandstones, 85 shales, &c., would thus be a recurrence at the surface of those bored through in the Bellarine District. The sandstones of the Barrabool Hills are extensively quarried, and used for building purposes in and around Geelong. They are variable in composi- tion and durability, and their prevailing dull, greenish-brown colour renders them objectionable for large buildings in which architectural effect is required. 475. SANDSTONE. Coarse-grained, very soft, and friable ; highly charged with carbonaceous matter ; slightly micaceous ; structure slaty. Cape Otway. 476. SANDSTONE. Rather coarse-grained, tough, and hard : thinly cleavable ; calcareous ; encloses carbonised fragments of plants. Sandford, Wannon River. SHALES. 477. SHALE, COAL SHALE. Soft and friable ; represents a but slightly indurated clay, with quite irregular cleavage ; full of remains of fossil plants. Gape Patterson. 478. SHALE, COAL SHALE. Same as No. 477. Cape Patter- son. 479. SHALE, COAL SHALE. Soft and friable ; represents a slightly indurated clay ; in parts somewhat arenaceous, and charged with carbonaceous matter ; cleavage quite irregular. From near Coleraine. 480. SHALE, COAL SHALE. Soft and friable, but some portions much harder than others ; slightly laminated ; cleavage planes uneven ; full of impressions of fossil plants (Tceniopteris Daintreei). Aloe, Gippsland. 481. SHALE, COAL SHALE. Very soft and friable, and slightly arenaceous ; much charged with carbonaceous matter, and full of carbonised fossil-plant remains. Moe, Gippsland. 482. SHA.LE, COAL SHALE. Very soft and friable, and highly charged with carbonaceous matter; resembles brown coal. Jfoe, Gippsland. CHEMICALLY-FORMED ROCKS. LIMESTONES. 483. LIMESTONE. Dense and argillaceous, and showing a tendency to "cone-in-cone" structure. From a half-mile south of Den Hills, near Muntham. 86 ORGANIC ROCKS. 484. COAL. Of rather poor quality, and rather thinly lamin- ated ; said to come from a seam three feet thick. Traralgon, South Gippsland. 485. COAL. Impure, of a rather shaly character; hard and much laminated. Specimens of this coal analysed by Mr. Cosmo Newbery gave 1. Raw Mineral. Carbon Hydrogen Oxygen and nitrogen Sulphur Ash .. 66-74 4-83 5-20 1-65 21-58 lOO'OO 2. Dried Mineral. Volatile matter Fixed carbon Ash 35-74 42-68 21-58 100-00 The raw mineral contains about 4 per cent, of hygroscopic water. Traralgon, South Gippsland. 486. COAL. Of inferior quality, on account of its being much fractured and traversed by small veins of calcite. From near Moe, Gippsland. 487. COAL. Of good quality, but very much fractured and laminated ; would deteriorate on exposure to the atmosphere. An analysis by Mr. Cosmo Newbery gave the following results : Water Volatile hydrocarbon Fixed carbon Ash 7-3 29-2 59-2 4-3 100-0 From the seam at Kilcunda, five miles from Griffiths Point. 488. COAL. Of good quality, but much fractured and lami- nated ; would probably deteriorate on exposure to the atmosphere. An analysis of the late Mr. Charles Wood gave : Volatile matter Fixed carbon... Hygroscopic water Ash 28.8 56.4 4.0 10.8 100.0 From the so-called " Queen Vein," 3 to 4 feet thick, Cape Pat- terson. 87 ROCKS OF THE TERTIARY OR CAINOZOIC AND RECENT PERIOD. According to Mr. Selwyn* the rock formations of the tertiary, including the recent period, whether regarded in their economical, physical, or geological aspects, occupy by far the most prominent place in Victorian geological history. Strata of sedimentary or volcanic origin, referable to some section of tertiary or recent time, occupy probably fully one-half, or over 40,000 square miles, of the surface of Victoria, forming deposits from a mere capping to over 300 feet thick. They are found resting unconformably on all the older formations, igneous and stratified, and range from sea-level to elevations of over 4000 feet. They include groups of strata of earth, loam, sand, clay, gravel, conglomerate, breccia, ferruginous and calcareous sandstone and grit, hard quartz rocks, marble and other kinds of limestone, and various volcanic pro- ducts, each of which has its more or less distinctive geological, palseontological, or mineral character, indicating it to be truly representative of the recognised eocene, miocene, pliocene, or pleistocene (including recent) deposits of Europe and other countries ; the terms being applied here, however, simply to denote lower, middle, upper, and recent tertiaries, rather than exact synchronism with European beds, or any ascertained relative percentage of living and extinct forms in their fossil contents. The oldest beds, probably upper eocene, occur on the east shore of Port Phillip Bay, resting on granite and mesozoic carbonaceous rocks. Very fine collections of fossils, now in the National Museum, have been procured from them. The beds are chiefly composed of blue clays and marls, with septarian-limestone nodules and selenite, and generally closely resemble the eocene strata of the Hampshire and London basins. The miocene division is chiefly represented in the marine tertiaries, extending from the western boundary of the colony to the east shore of Port Phillip Bay, being well ex- posed in the coast cliffs and river banks, and occurring sometimes, as at the Muddy Creek, near Hamilton, upwards of forty miles inland. Its upper subdivisions also occupy a long, narrow strip of coast country, nowhere, however, exceeding sixteen miles in width, between Wilson's Promontory and Cape Howe, and form cliffs on the northern shores of the Gippsland lakes, and on some of the rivers flowing into them. From the mouth of Spring Creek to the Bird Rock, fourteen miles south of Geelong, they * " Notes on the Physical Geography, Geology, and Mineralogy of Vic- toria." Intercolonial Exhibition Essays, 1866. 88 are exposed in the fine cliff sections, reaching a thickness of 273 feet, the sequence of the beds being as follows : UPPER MIOCENE. 80 feet : Hard, thin-bedded, sandy limestone (the calcareous portion consisting almost entirely of fossils), the probable equiva- lent of the Mount Gambier series, described by the Rev. Julian Woods. MIDDLE MIOCENE. 80 feet : Soft, brown, sandy clay. 30 feet : Brown, blue, and yellow sandy clays, containing abundance of gypsum. 1 foot : Very hard crystalline sandstone. 12 feet : Brown sandy clay, poor in gypsum. 1 foot : Very hard crystalline sandstone. 5 feet : Brown sandstone, containing abundance of gypsum. 10 feet : Blue marl, containing septaria, gypsum, and iron pyrites. 8 feet : Friable thin sandstone, with thin bands of gypsum. LOWER MIOCENE. 1 foot : Very hard band of crystalline sandstone. 17 feet : Soft brown sandstone, with thin bands of harder material. 20 feet : Thin-bedded brown sandstone. 8 feet : Blue and grey friable sandstone. Of miocene age, clearly antecedent in date to the upper and middle subdivisions, are also the so-called "lower drifts"- occurring near Steiglitz, at the Golden River, Tea-tree Creek, the Upper Moorabool, Parwan Creek, Bacchus Marsh, and Ballan which, though in many respects quite similar in character to, and forming in places actually, the bottom or floor of real older gold-drift, have not themselves as yet proved, nor are perhaps likely to prove, productive in gold. The deposits of pliocene and recent age, both of marine and fresh-water origin, have a far wider surface-range than the older marine tertiary deposits ; they cover these all along the eastern seaboard, and occupy also the vast extent of the Lower Murray Plains, But what renders them besides the most important divisions of the period is that they embrace the auriferous drifts, the determination of whose payable range is a matter of the utmost consequence as affecting the probable extent and produc- tiveness of the goldfields. During the progress of the late geological survey it has been clearly established that there are at least three distinct periods of deposition ; the earliest not older than pliocene, whilst the newest is probably due to causes still in operation. In absence of satisfactory palseontological evidence, these three drift-deposits have provisionally been classed as older 89 pliocene, newer pliocene, and post-pliocene, including recent ; or as lower, middle, and upper gold- drifts. The mode of relation of these three drifts in some of our most important goldfields to more or less extensive streams of newer basalt-lava would seem to afford a ready means of distinguishing at least between the first two (lower and middle) and the upper gold-drifts ; for the former, being older than the lava, are covered by it, whilst the latter, being more recent, do in places actually overlie the lava. However, besides that this distinction is only of local application, there are also exceptions to the above relations in the neighbour- hood of basaltic craters and points of eruption that were more recently active for instance, at Mounts Franklin, Buninyong, Warrenheip, &c. Though most of the lava-flows discharged from these volcanic vents (the latter show at least four flows) are no doubt older than the upper gold-drift still some are certainly more recent, as they have been poured into valleys filled with this drift. A fine instance of this is exhibited at Yandoit, near Mount Franklin. Although associated basaltic flows do not therefore in all cases present a sure guide for identifying any of the three drifts, each of the latter can, however, be easily recog- nised by special characteristics of its mass, relative position, and other circumstances, as the following description will show : I. THE OLDER PLIOCENE, OE LOWER GOLD-DRIFT. The special character of this drift is that its gravelly portion is principally composed of quartz pebbles or boulders, which, as well as the gold contained in it, are perfectly rounded or water- worn. Although it is in some places as, for instance, in the White Hills at Bendigo, the Loddon valley hills, &c. well arranged according to size i.e., from small to large, from the top downward still it is more frequently observed that though the coarsest the real boulder-drift lies at the bottom, the superincumbent portion is variously composed in different localities. In our western goldfields Ballarat, Castlemaine, Avoca, &c. it consists of layers of sand and clay, of sandy and clayey, coarse and fine gravel, and where filling deep valleys and carrying the present surface drainage channels, beds of real drift- sand are not unfrequent. In the large deposits of this drift discovered on the Tangil River, Gippsland, the pebble drift, or rounded quartz- gravel, is only a few feet thick, but covered in places by over 100 feet in thickness of an indurated, yellow or brown, very arenaceous clay, which so closely resembles the soft, yellow, silurian sandstone the rock-bottom of the district 90 that, except for its horizontal bedding, and the absence in it of small quartz-veins that are always present in the true bottom- rock, it might be easily mistaken for the latter. The predominating colours of this drift are either white or brown, or white and brown mottled, whilst the bottom layer or washdirt is often rich in a black carbonaceous clay, or shows a covering of this clay, in which remnants of trees as branches, roots, trunks, leaves, seedvessels, &c., all more or less carbonised, or sometimes wholly or partially converted into iron pyrites are often found enclosed. In some places beds of real lignite, or brown coal, have also been found above the washdirt. Layers of hard ferruginous conglomerate (see specimens in the collection), from a few inches to several feet in thickness, and requiring blasting operations in working, are hardly ever absent, especially near the bottom of the deposit, and a peculiar, extremely hard and dense siliceous cement a real quartzite is sometimes observed in cakes near and at the top along basalt escarpments, or where the drift deposit is exposed near basalt-flows. The fact that these cement cakes, which are often many feet thick, do not extend beneath the basalt, but occur only where the drift was exposed to the atmosphere through denudation of the basalt, would tend to indicate that they are, as it were, the products of local metamor- phism of sandy clay or sand, in which siliceous waters, produced through the denudation of the basalt, in connection with atmos- pheric agencies, performed important parts. Touching the mode of occurrence of the drift it is twofold : (a) As Hills, either solitary or in series, more or less con- nected, bounding gullies and flats, or more rarely rising in the centre of flats as, for instance, the White Hills, Maryborough, a hill in the Loddon River flat below Guildford, &c. Where these hills are covered by basalt, they are generally of far larger size than where exposed (Loddon valley outliers,