J. B. Hatcher — Geology of Southern Patagonia. 347 



volume of water, until an equilibrium was reached, which 

 would result in a small body of concentrated salt water, often 

 with a deposit of salt at the bottom, due to precipitation from 

 an oversaturated solution. This is exactly what is found to be 

 the case in hundreds of places in this region. In all of these 

 salt lakes the bluffs are always much lower on one side than on 

 any of the other sides, and it is quite apparent that the present 

 drainage system corresponds very closely with that of the 

 former period of erosion. 



Sketch map of Argentine territory of Santa Cruz. 



That the salt in these lakes has been derived from confined 

 bodies of sea water and has not been leached from the sur- 

 rounding bluffs, is clearly shown by the numerous springs of 

 sweet water in many places, alongside of the salt lakes. All 

 the streams and springs of this region have good fresh water. 

 ^We never saw a single spring the waters of which were saline, 

 and the surface of the ground is everywhere remarkably free 

 from incrustations by any alkaline or other salts. 



