116 Proceedings of ilie Royal Society of Victoria. 



follows Selwyn's use of the term, and I adopt their nomenclature 

 in this paper. 



It may be both interesting and profitable to collect the 

 opinions of some leading Victorian geologists on the question 

 under review, for we have gravels of all ages, and if only those of 

 middle tertiary age and those younger contain payable gold, 

 then mining must be greatly restricted to what it otherwise 

 would be if gravels formed from recent times right back to 

 Palaeozoic times might be in some places profitably worked for 

 their golden contents. 



In a paper read before this Society in 1886, " On the Sedi- 

 mentary, Metamorphic and Igneous Rocks of Ensay " (pp. 56 

 to 60), Mr. A. W. Howitt states that in his opinion certain 

 of the sedimentary rocks of the Ensay district were probably 

 altered to schists at the close of the Silurian period, and that 

 the formation of the schistoze structure was probably due to 

 certain conditions arising from the forces which folded and 

 contorted the strata. Also that the Silurian sediments of 

 Gippsland were much folded before the Middle Devonian 

 limestones of Buchan and Bindi were deposited. 



Mr. Howitt says further^ that probably we can refer the 

 formation of the auriferous veins and lodes generally occurring 

 in the Silurian and Devonian formations to plu tonic and volcanic 

 action which prevailed about the close of the Silurian period 

 and was continued in Lower Devonian and on until the 

 geological record closes in the Upper Devonian period. 



Murray'^ writes that all fissures now reefs, were not formed 

 in one short period, and that most of them resulted from 

 movements connected with, or closely following the corrugation 

 of the strata. The existence of quartz veins in our Upper 

 Palaeozoic conglomerates which contain pebbles of water-worn 

 quartz, proves that the formation of quartz veins was not 

 confined to Silurian rocks, though it attained its supreme 

 development in them. Most of the quartz veins in the 

 Silurian rocks of Victoria were formed prior to the formation 

 of the Upper Pakeozoic rocks. 



1 In Murray, ^c, p. 147. 



2 Murray, I.e., p. 140. 



