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CHAPTER X. 



ON THE PLAINS AND VALLEYS OF CHILE: — SALIFEROUS 

 SUPERFICIAL DEPOSITS. 



Basin-like plains of Chile ; their drainage^ their marine origin — 

 Marks of sea-action on the eastern flanks of the Cordillera — Sloping 

 terrace-like fringes of stratified shingle within the valleys of the 

 Cordillera; their marine origin — Boulders in the valley of the 

 Cachapual — Horizontal elevation of the Cordillera — Formation of 

 valleys — Boulders moved oy earthquake-waves — Saline superficial 

 deposits — Bed of nitrate of soda at Iquique — Saline incrustations — 

 Salt lakes of La Plata and Patagonia : purity of the salt ; its origin. 



The space between the Cordillera and the coast of Chile is 

 on a rude average from eighty to above one hundred 

 miles in width ; it is formed, either of an almost 

 continuous mass of mountains, or more commonly of 

 several nearly parallel ranges, separated by plains; in 

 the more southern parts of this province the mountains 

 are quite subordinate to the plains; in the northern 

 part the mountains predominate. 



The basin-like plains at the foot of the Cordillera 

 are in several respects remarkable ; that on which the 

 capital of Chile stands is fifteen miles in width, in an 

 east and west line, and of much greater length in a 

 north and south line ; it stands 1,750 feet above the sea; 

 its surface appears smooth, but really falls and rises 

 in wide gentle undulations, the hollows corresponding 

 with the main valleys of the Cordillera : the striking 

 manner in which it abruptly comes up to the foot of 



