LAKE TITICACA. 



361 



basin, separated from Titicaca proper by tbe Strait of Tiquina, takes the name of 

 TJnimarca or Guiuimarca, that is, " Dried Lake," as Billinghurst explains the 

 word. The two sections have a joint area of 3,300 square miles, with an extreme 

 depth of 700 feet. 



As the deepest abysses on the oceanic seaboard generally occur at the foot of the 



Fig. 139. — Old Lake of the Bolivian Plateau. 

 Scale 1 : 7,000,000. 





West oF Green«,cU 



£7" 



Depths. 



Old lake. 



to .^00 

 Fathoms. 



500 Fathoms 

 and upwards. 



124 Miles. 



loftiest mountains, here also the greatest depths are dominated by the snowy peaks 

 of Illampu. While the annual change of level due to evaporation and the rains 

 amounts to about 4 feet, a slight absolute subsidence seems to have taken place^ 



