164 
THE GEOLOGIST. 
paliBozoic rocks, commencing with scliista, much cleaved and contorted, and con 
taining TAngu'cc and Graptolifcs, passing through a series of schists, and sandstones 
with Trilohiles and many other fossils characteristic of the lower, middle, and 
upper Silurian scries 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 pahx;ozoic rocks. A list of about sixty genera 
of Silurian fossils, including many new species was appended. 
The gold-bearing quartz-veins of the Silui-ian 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 Graptoliles and Ling^dce occur in tlie 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 aifected their general strike or dip, but appear to have themselves partaken 
of the movements which have placed these Silurian rocks iu their present higldy 
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. Tlicse are overlaid by slieets 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 Waruambool, marine or estuary beds of 
probably the same age are overlaid by volcanic aslies. 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 IMacedon, a few miles nortli 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 1,001) 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 »ome 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 aluminous and 
contain pyrites. Their strike is rather uniform ; nearly coinciding witli 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 beach-like 
conglomerate — is found, not iu the deep section, but on the surface of the schist 
country. It is regarded as of marine origin by tiie 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 aurifero\is, and 
is covered by an ancient humus, which, in the deep section, is found to contain stems 
