chap. ix. Elevation of Coquimbo. 247 



neighbourhood of Plazilla and Catapilco, at heights of 

 between 200 and 800 feet, the number of comminuted 

 shells, with some perfect ones, especially of the Meso- 

 desma, packed in layers, was truly immense : the land 

 at Plazilla had evidently existed as a bay, with abrupt 

 rocky masses rising out of it, precisely like the islets in 

 the broken bays now indenting this coast. On both 

 sides of the rivers Ligua, Longotomo, Guachen, and 

 Quilimari, there are plains of gravel about 200 feet in 

 height, in many parts absolutely covered with shells. 

 Close to Conchalee, a gravel-plain is fronted by a lower 

 and similar plain about sixty feet in height, and this 

 again is separated from the beach by a wide tract of 

 low land : the surfaces of all three plains or terraces 

 were strewed with vast numbers of the Concholepas, 

 Mesodesma, an existing Venus, and other still existing 

 littoral shells. The two upper terraces closely resemble 

 in miniature the plains of Patagonia ; and like them 

 are furrowed by dry, flat-bottomed, winding valleys. 

 Northward of this place I turned inward ; and therefore 

 found no more shells : but the valleys of Chuapa, Illapel, 

 and Limari, are bounded by gravel- capped plains, often 

 including a lower terrace within. These plains send 

 bay-like arms between and into the surrounding hills; 

 and they are continuously united with other extensive 

 gravel-capped plains, separating the coast mountain- 

 ranges from the Cordillera. 



Coquimbo, 



A narrow fringe-like plain, gently inclined towards 

 the sea, here extends for eleven miles along the coast, 

 with arms stretching up between the coast-mountains, 

 and likewise up the valley of Coquimbo : at its southern 

 extremity it is directly connected with the plain of 



