276 Recent Elevatory Movements, paet n. 



beaches, sand-dunes, and successive terraces of gravel, 

 all above the present level of the sea. From the steep- 

 ness of the land on this side of the continent, shells 

 have rarely been found at greater distances inland than 

 from two to three leagues ; but the marks of sea-action 

 are evident farther from the coast ; for instance, in the 

 valley of Guasco, at a distance of between thirty and 

 forty miles. Judging from the upraised shells alone, 

 the elevation in Chiloe has been 350 feet, at Ooncepcion 

 certainly 625 feet, and by estimation 1,000 feet; at 

 Valparaiso 1,800 feet; at Coquimbo 252 feet; north- 

 ward of this place, sea-shells have not, I believe, been 

 found above 800 feet ; and at Lima they were falling 

 into decay (hastened probably by the salt) at eighty-five 

 feet. Not only has this amount of elevation taken 

 place within the period of existing Mollusca and Cir- 

 ripecles ; but their proportional numbers in the neigh- 

 bouring sea have in most cases remained the same. 

 Near Lima, however, a small change in this respect 

 between the living and the upraised was observed : at 

 Coquimbo this was more evident, all the shells being 

 existing species, but with those embedded in the upper- 

 most calcareous plain not approximating so closely in 

 proportional numbers, as do those that lie loose on its 

 surface at the height of 252 feet, and still less closely 

 than those which are strewed on the lower plains, which 

 latter are identical in proportional numbers with those 

 now cast up on the beach. From this circumstance, 

 and from not finding, upon careful examination, near 

 Coquimbo any shells at a greater height than 252 feet, 

 I believe that the recent elevation there has been much 

 less than at Valparaiso, where it has been 1,300 feet, 

 and I may add, than at Concepcion. This considerable 

 inequality in the amount of elevation at Coquimbo and 

 Valparaiso, places only 200 miles apart, is not im- 



