Mr. J. Phillips oa the Gold-field of Ballaarat, Victoria. 401 



rests on the older drifts ; and at Tower Hill, near Warnambool, ma- 

 rine or estuary beds of probably the same age are overlaid by vol- 

 canic ashes. A third and still more recent gold-drift is found on 

 the surface, overlying indifferently any of the older deposits. 



The gold is found at the base of these drifts or gravels, which are 

 the result of the immediate waste, by atmospheric and fluviatile 

 action, of older masses, and ha^'e not been far transported. The 

 largest amount of gold is found in the drifts when near the Silurian 

 schists. The author believes that there is every probability of gold- 

 deposits existing under the greater jiortion of the lava-plains of the 

 region to the westward. 



Mr. Selwyn also described a cave which he had discovered in the 

 basaltic lava of Mount Maccdcn, a few miles north of Melbourne, 

 and in which he had found bones of manj' living species of mam- 

 mals, including the " devil " of Tasmania, and the Dingo or native 

 dog. The cave is about 1000 feet above the sea-level, and thirty 

 miles inland. 



2. " Notes on the Gold-field of Ballaarat, Victoria." By Mr. 

 John Phillips, C.E., Surveyor in the Government Service of Victoria. 



All the Victorian gold-tields are near granite, and some are on it. 

 The granite at Ballaarat is fine and even-grained, and the schists lie 

 against it. Between these rocks the junction is abrupt ; there is 

 little or no gneiss, and no porphyritic or other veins were observed. 

 The schists are greenish, and are occasionally chloritic, micaceous, 

 aluminous, and siliceous, and are traversed by quartz-veins, from 

 less than an inch to one foot in thickness. The schists in the upper 

 j)ortion are more quartzose and contain oxides of iron ; lower down 

 they are more aluminous and contain pyrites. Their strike is rather 

 uniform ; nearly coinciding with the true meridian, while the clea- 

 vage and quartz-veins are not regular in strike. The workings at 

 Ballaarat have exhibited a section of 300 feet in thickness, consist- 

 ing of gravels, sands, clays, and trap-rocks. The oldest drift or 

 gravel — a beach-like conglomerate — is found not in the deep section, 

 but on the surface of the schist-country. It is regarded as of marine 

 origin by the author, and is composed of quartz, and contains gold 

 at its base. Another drift has been deposited in gullies cut through 

 the oldest drift and deep into the schists. This also is auriferous, 

 and is covered by an ancient humus, which, in the deep section, is 

 found to contain stems of trees, and to be covered over by a trap- 

 rock enclosing upright trees. This fossil wood is usually but little 

 altered in its texture and ligneous qualities ; its colour is changed 

 from that of red birch to cocoa or ligmim-vitaB. But some of it has 

 passed into jet ; and both the charred and the uncharred woods 

 have much bright pyrites in them. I'he flora of this old land-sur- 

 face resembles that of the present d<ay. 



This first trap is covered by green and brownish clay and sand, 

 which are succeeded by another trap, having a line of charred vege- 

 table matter at its base, and also having a similar covering of clay 

 and sand. These clay and sand dejiosits are regarded by the author 

 aa being of lacustrine origin ; the volcanic rocks having dammed up 



