164 



THE GEOLOGIST. 



paleozoic rocks, commencing with schists, much cleaved and contorted, and con- 

 taining Lingular and Graptolites, passing through a series of schists, and sandstones 

 with Trilohites and many other fossils characteristic of the lower, middle, and 

 upper Silurian series of Britain, and terminating with Devonian and carboni- 

 ferous rocks ; and he remarked that the younger or Oolitic (?) coal-bearing beds on 

 the west rest unconformably on the pal'cBozoic rocks. A list of about sixty genera 

 of Silurian fossils, including many new species was appended. 



The gold-bearing quartz-veins of the Silurian rocks appear to the author to be 

 dependent more on their proximity to some granitic or other plutonic mass than 

 on the age of the rocks in which they occur. Quartz veins do not appear to 

 traverse the Oolitic (?) coal-rocks, which are of newer date than the granites of 

 this district. 



The author's observations refer chiefly to Bendigo, Ballaarat, and Steiglitz 

 gold-fields, where Graptolitcs and Lingular occur in the schists, which are traversed 

 by the gold- quartz- veins. The granites here do not contain gold ; and though 

 they have altered the slate-rocks at the line of junction, yet they do not seem to 

 have alfected their general strike or dip, but appear to have themselves partaken 

 of the movements which have placed these Silurian rocks in their present highly 

 inclined and contorted positions, and given them their very uniform meridional 

 direction, 



Mr. Selwyn recognises gold-bearing drifts of three distinct ages. The lowest 

 contains large quantities of wood, seed-vessels, &c., at various depths, to 280 feet, 

 and is associated with clays, sands, and pebbles. These are overlaid by sheets of 

 lava. A more recent auriferous drift, containing also bones of both extinct and living 

 marsupial quadrupeds, overlies these lavas in some places; in others it rests on 

 the older drifts ; and at Tower Hill, near Warnambool, marine or estuary beds of 

 probably the same age are overlaid by volcanic 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 

 have not been far transported. The largest amount of gold is found in the drifts 

 near the Silurian schists. The author believes that there is every proba- 

 bility of gold deposits existing under the greater portion 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 ^\ acedon, a few miles north of Melbourne, and in which he had found bones 

 of many living species of mammals, including the " devil " of Tasmania, and the 

 Dingo or native dog. The cave is about 1,000 feet above the sea-level, and thirty 

 miles inland. 



2. "Notes on the Gold fields of Ballaarat, Victoria." By Mr. John Phillips, 

 C.E., Surveyor in the Government Service of Victoria. Communicated by Sir 

 R. I. Murchison, V.P.G.S. 



All the Victorian gold-fields 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 phorpyritic 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 portion are more 

 quartzose and contain oxides of iron ; lower down they are more aluDiinous and 

 contain pyrites. Their strike is rather uniform ; nearly coinciding with the true 

 meridian, while the cleavage and quartz-veins are not regular in strike. The 

 workings at Ballaarat have exhibited a section of 300 feet in thickness, consisting 

 of gravels, sands, clays, and trap-rocks. The oldest drift, or gravel — a bcach-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 b> an ancient humus, which, in the deep section, is found to contain stems 



