THE 



JOURNAL OF GEOLOGY 



NOVEMBER-DECEMBER, 1896. 



THE AGE OF THE AURIFEROUS GRAVELS OF THE 

 SIERRA NEVADA.' WITH A REPORT ON THE 

 FLORA OF INDEPENDENCE HILL.^ 3 



It is the purpose of this paper to attempt to fix more defi- 

 nitely than has hitherto been done the age of the auriferous, 

 detrital rocks of the Sierra Nevada, resting uncomformably on 

 the bed rock series, generally at considerable elevations above 

 the present drainage and covered by volcanic flows. This series 

 is commonly designated as the " Auriferous Gravels." It is also 

 the purpose to indicate briefly the more salient features of the 

 Cretaceous and Cenozoic history of the Sierra Nevada. The 

 results are the outcome of a study of the range between the 

 parallels of 38° 30' and 39° 30', extending over a number of 

 years, and are to be set forth more fully in a bulletin now in 

 preparation. 



The auriferous gravels have been carefully studied by Pro- 

 fessor Whitney, who determined them as fluviatile deposits and 

 assigned to them a Pliocene Age, basing his conclusions chiefly 

 on the palseobotanical studies of Professor Lesquereux. At the 

 same time Professor Whitney states that very probably aurifer- 

 ous gravels may have accumulated during the whole of the 

 Tertiary period. On the maps of the United States Geological 



' By Waldemar Lindgren. 



= By F. H. Knowlton. 



3 Published by permission of the Director of the United States Geological Sur- 

 vey. 

 Vol., IV, No. 8. 88i 



