144 Notes on the Area of Intrusive Rocks at Dargo. 



was formed, in which the prospectors held one-half of the 

 shares, the remainder being held by two shareholders in 

 Sale, with the exception of a few shares held at Dargo 

 and Bairnsdale. A steam-engine, working a battery of 

 eight stampers, was erected at the mine, which was 

 managed for the company by one of the shareholders 

 (Mr. H. Jorgensen). The gold obtained, of which I 

 subjoin .a tabulated return, was from the stone only, 

 and not from the pyrites, which has not been separated 

 from the tailings or treated in any manner. The company 

 is still constituted as above-mentioned, and up to the end of 

 May, 1886, had produced an amount of gold equal in value 

 to the total cost of machinery and labour. The mine and 

 machinery are at this time let on tribute. 



Year. 





Number of Tons of 



Total Yield. 







Quartz Crushed. 











oz. dwt. gr. 



1881 



.. 



145 



142 



1882 



... 



364 



258 13 10 



1883 



... 



201 



196 5 5 



1884 to June 



9, 







1886 ... 





481 



417 14 



1881toJune9,1886 



1,191 



1014 12 15 



The yield of gold varied from 9 dwts. 19grs. to 1 oz. 

 6 dwts. per ton of quartz. 



The interest attaching to this mine is due to the evidence 

 it affords that such narrow auriferous veins as those at Orr's 

 Creek may, with careful management, even be capable of 

 yielding a profit. To this subject I shall refer again later on. 

 Mr. Kelly informs me that the gold from the Exhibition 

 mine was worth £4 per oz., which would agree nearly with a 

 composition of Au. 94-20, Ag. 5'80. This proportion is 

 higher, as to the gold, than I should have expected in the 

 Dargo area. Some j^ears ago I examined a series of samples 

 of alluvial gold from different geological formations in Gipps- 

 land and at Omeo, with the result that I found the 

 composition in Silurian areas to lie between the proportions 

 of silver alloy to gold of 1:12 and 1:40, and in areas of 

 metamorphic or plutonic rocks of 1:2"2 and 1:9.* 



* A number of these determinations were recorded in Eeports of Progress, 

 II,, p. 69, and III., p. 238, Geological Survey of Victoria. 



