1835.] SHINGLE-TERRACES OF COQUIMBO. 329 



command of mind, so generally experience during earthquakes. 

 I think, however, this excess of panic may be partly attributed to 

 a want of habit in governing their fear, as it is not a feeling they 

 are ashamed of. Indeed, the natives do not like to see a person 

 indifferent. I heard of two Englishmen who, sleeping in the open 

 air during a smart shock, knowing that there was no danger, did 

 not rise. The natives cried out indignantly, " Look at those here- 

 tics, they will not even get out of their beds ! " 



I spent some days in examining the step-formed terraces of 

 shingle, first noticed by Captain B. Hall, and believed by Mr. Lyell 

 to have been formed by the sea, during the gradual rising of the 

 land. This certainly is the true explanation, for I found numerous 

 shells of existing species on these terraces. Five narrow, gently 

 sloping, fringe-like terraces rise one behind the other, and where 

 best developed are formed of shingle : they front the bay, and 

 sweep up both sides of the valley. At Guasco, north of Coquimbo, 

 the phenomenon is displayed on a much grander scale, so as to 

 strike with surprise even some of the inhabitants. The terraces 

 are thero much broader, and may be called plains ; in some parts 

 there are six of them, but generally only five; they run up the 

 valley for thirty-seven miles from the coast. These step-formed 

 terraces or fringes closely resemble those in the valley of S. Cruz, 

 and except in being on a smaller scale, those great ones along 

 the whole coast-line of Patagonia. They have undoubtedly been 

 formed by the denuding power of the sea, during long periods of 

 rest in the gradual elevation of the continent. 



Shells of many existing species not only lie on the surface of the 

 terraces at Coquimbo (to a height of 250 feet), but are embedded 

 in a friable calcareous rock, which in some places is as much as 

 between twenty and thirty feet in thickness, but is of little extent. 

 These modern beds rest on an ancient tertiary formation containing 

 shells, apparently all extinct. Although I examined so many hun- 

 dred miles of coast on the Pacific, as well as Atlantic side of the 

 continent, I found no regular strata containing sea-shells of recent 

 species, excepting at this place, and at a few points northward on 

 the road to Guasco. This fact appears to me highly remarkable ; 

 for the explanation generally given by geologists, of the absence in 

 any district of stratified fossiliferous deposits of a given period, 

 namely, that the surface then existed as dry land, is not here appli- 



