254 Gravel-Terraces of Coquimbo part n. 



facts given at Valparaiso, and lastly from the evidence 

 of a slow rising lately or still in progress here, it appears 

 to me far more probable, that the movement has been 

 slow. The existence of these successive escarpments, 

 or old cliff-] ines, is in another respect highly instructive, 

 for they show periods of comparative rest in the eleva- 

 tory movement, and of denudation, which would never 

 even have been suspected from a close examination of 

 many miles of coast southward of Coquimbo. 



We come now to the terraces on the opposite sides 

 of the east and west valley of Coquimbo : the following 

 section is taken in a north and south line across the 

 valley at a point about three miles from the sea. The 

 valley measured from the edges of the escarpments of 

 the upper plain (F) (F) is about a mile in width ; but 

 from the bases of the bounding mountains it is from 

 three to four miles wide. The terraces marked with 

 an interrogative do not exist on that side of the valley, 

 but are introduced merely to render the diagram more 



intelligible. 



No. 24. 



North and South Section across the Valley of Coquimbo. 



Level of sea. 



Vertical scale yoth of inch to 100 feet : horizontal scale mnch contracted : terraces 

 marked with (?) do not occur on that side of the valley, and are introduced only 

 to make the diagram more intelligible. A river and bottom-plain of valley C, E, 

 and F. on the south side of valley, are respectively, 197, 377, and 420 feet above 

 the level of the sea, 



A A The bottom of the valley, believed to be 100 feet above the sea : it is continu- 

 ously united with the lowest plain (A) of the former section. 



B This terrace higher up the valley expands considerably ; seaward it is soon lost, 

 its escarpment being united with that of (C) : it is not developed at all on the 

 south side of the valley. 



C This terrace like the last, is considerably expanded higher up the valley. These 

 two terraces apparently correspond with (B) and (C) of the former section. 



D is not well developed in the line of this section ; but seaward it expands into a 

 plain : it is not present on the south side of the valley ; but it is met with, as 

 stated under the former section, a little south of the town. 



