86 GEOLOGICAL HISTORY OF LAKE LAHONTAN. 



The freshening of lakes by complete evaporation is one of the most 

 interesting results of the processes we have been tracing. Perhaps the 

 strongest proof that the burial of desiccation products beneath earthy sedi- 

 ments is competent to convert a lake from a saline to a fresh condition is 

 furnished by a number of the existing lakes of Nevada and Oregon, which 

 are either fresh to the taste, or else hold but a fraction of 1 per cent, of 

 saline matter in solution, but occur in comparatively broad drainage-basins 

 that have not overflowed since the beginning of the Quaternary. This 

 is illustrated especially by the present condition of the lakes of the Lahon- 

 tan basin, as will be shown in treating the chemistry of the former lake 

 (postea, page 229). 



