536 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Mar. 10, 



estuary beds, with shells of living species, are overlaid by thick 

 deposits of volcanic ashes*. 



Resting indifferently on any of the older deposits is a third or 

 recent gold-drift (No. 4, figs.l, 2, 3), the result of recent and existing 

 atmospheric and fluviatile action. It is formed by the waste of all 

 the older deposits. 



The mode of occurrence of the gold is as follows : — It is found at 

 the base of 1, 3, and 4, when resting on each other, or on the Silurian 

 gold-bearing rocks (6) ; never when resting on the trap (2) or the 

 granite (a) if far removed from the Silurian or Miocene rocks 

 (6 and 1). The gold-bearing gravels are the result of the immediate 

 waste of older masses, and have not been transported far. This, 

 however, does not altogether apply to the eastern gold-fields, where 

 gold is found in the granite. 



As a general rule, the heaviest gold- deposits and the largest nug- 

 gets are found only at the base of the Miocene, Pliocene, and recent 

 drifts (1,3, and 4) when they rest directly on the Silurian strata. In 

 the Ballarat section (fig. 3), at the line marked z, three " bottoms'' 

 or deposits of gold would be found in sinking through the bases of 

 4, 3, and 1. 



I have never yet been able to discover evidence of anything re- 

 sembling glacial action ; but I have not been in those parts of the 

 colony where, if in existence, it would be most likely to be seen, viz. 

 on the flanks of the Australian Alps. 



I have discovered a cave in the basalt of Mount Macedon, a few 

 miles north of Melbourne, containing bones of many living species, 

 including the "Devil" of Tasmania, not now living on the mainland; 

 and also the Dingo, or native dog. In the bones sent by my assistant 

 Aplin and myself to Professor M'Coy, he recognized " two fragments 

 of the superior maxillary bone, with the long transverse molar, the 

 smaller molar, and the second molar, together with two rami of the 

 inferior maxillary bone, beyond all doubt, of the Dingo at present 



Fig. 4 — Section of the Ravine and Cave. 



a. Basalt (Miocene?). 



b. Schists and sandstones (Lower Silurian). 



c. Mouth of Cave. 



living in this country." In the cave were also found fragments of 

 the skulls of what appear to be a "new genus of carnivorous ani- 



* See Mr. R. B. Smyth's paper on the Extinct Volcanos of Victoria, above, 

 p. 231.— Edit. 



