154 



GEOLOGY OF THE COMSTOCK LODE. 



The following analyses were made for Dr. G. W. Hawes by Mr. F. P. Dewey; 

 Feldspar of specific gravity between 2.75 and 2.70. 



Feldspar of specific gravity between 2.70 and 2.68. 



Table 8. — Assays of Comstock rovls.^ 

 By J. S. Curtis. 



Granite ' Kfd Jacket mine 



Granular diorite ' Bullion Ravine, at intersection of Water Company's flume 



Do Bullion Ravine, 200 feet above flume 



Do Bullion Ravine. 2,000 feet above flume 



Do Most westerly diorite cropping 



Dark, fine-grained diorite McKibbcn tunnel 



Dark, coarse-grained diorite Bottom of I7ni07l shaft, 2,625 feet 



Porphyiitic diorite ' Head of Ophir Ravine, decomposed 



Do I Ophir, 2,500, Union connection, decomposed 



Do (Sayage, 2, 100. south drift 20 feet from east cross-cot 



Granular diorite j Caledonia 



Micaceous diorite-porphyry | Overman, 1,600, 250 feet east of shaft 



Do j 800 feet east of TFaiier Z)f/ea( shaft 



Earlier diabase SiUro tunnel at Savage connection, fresh 



$0.03 

 0.19 

 0.04 

 0.03 

 0.08 

 0.1 1 

 0.15 

 0. n 

 0.30 

 0.12 

 0.05 

 0.11 

 0.07 

 0.22 



1 For remarks on these assays see page 223. 



