120 RECENT AND POST-PLIOCENE FORMATIONS. [Cu. X 



suggested, that the mean rate of continuous vertical elevation has 

 amounted to 2i feet in a century (and this is probably a high average), 

 it would require 27,500 years for the sea-coast to attain the height of 

 Too feet, without making allowance for any pauses such as are now ex- 

 perienced in a large part of Norway, or for any oscillations of level. 



In England, buried ships have been found in the ancient and now 

 deserted channels of the Rotlier in Sussex, of the Mersey in Kent, and 

 the Thames near London. Canoes and stone hatchets have been dug 

 up, in almost all parts of the kingdom, from peat and shell-marl ; but 

 there is no evidence, as in Sweden, Italy, and many other parts of the 

 world, of the bed of the sea, and the adjoining coast, having been up- 

 lifted bodily to considerable heights within the human period. Recent 

 strata have been traced along the coasts of Peru and Chili, inclosing 

 shells in abundance, all agreeing specifically with those novf swarming in 

 the Pacific. In one bed of this kind, in the island of San Lorenzo, near 

 Lima, Mr. Darwin found, at the altitude of 85 feet above the sea, pieces 

 of cotton-thread, plaited rush, and the head of a stalk of Indian corn, 

 the whole of which had evidently been imbedded with the shells. At 

 the same height on the neighboring mainland, he found other signs cor- 

 roborating the opinion that the ancient bed of the sea had there also 

 been uplifted 85 feet, since the region was first peopled by the Peruvian 

 race.'^ But similar shelly masses are also met with at much higher 

 elevations, at innumerable points between the Chilian and Peruvian 

 Andes and the sea-coast, in which no human remains were ever, or in 

 all probability ever will be, discovered. 



In the West Indies, also, in the island of Guadaloupe, a solid lime- 

 stone occurs, at the level of the sea-beach, enveloping human skeletons. 

 The stone is extremely hard, and chiefly composed of comminuted shell 

 and coral, with here and there some entire corals and shells, of species 

 now living in the adjacent ocean. With them are included arrow-heads, 

 fi-agments of pottery, and other articles of human workmanship. A 

 limestone with similar contents has been formed, and is still forming, in 

 St. Domingo. But there are also more ancient rocks in the West Indian 

 Archipelago, as in Cuba, near the Havana, and in other islands, in 

 which a! ? shells identical with those now living in corresponding lati- 

 tudes ; some well-preserved, others in the state of casts, all referable to 

 the post-pliocene period. 



I have already described in the seventh chapter, p. 84, what would be 

 the effects of oscillations and changes of level in any region drained by 

 a great river and its tributaries, supposing the area to be first depressed 

 several hundred feet, and then re-elevated. I believe that such changes 

 in the relative level of land and sea have actually occurred in the post- 

 pliocene era in the hydrographical basin of the Mississippi and in that 

 of the Rhine. The accumulation of fluviatile matter in a delta during 

 a slow subsidence may raise the newly gained land superficially at the 



* Journal, p, 451. 



