12 



CONTINENTS ONCE COVERED BY THE OCEAN. 



posed to view the succession of the different rocks and strata in many 

 parts of our island, and has enabled us to obtain a correct knowledge 

 of their thickness and direction, and of the organic remains pecu- 

 liar to each series. 



Before concluding the present chapter, let us take a view of some 

 of the more striking appearances, which afford demonstrative evi- 

 dence, that great changes have taken place in the relative level of the 

 present continents, and that the ocean has, in former ages, rolled its 

 waves over what are now the most elevated parts of the earth. Ma- 

 ny proofs of this exist in our own island, and in various parts of the 

 world. 



The calcareous or limestone mountains in Derbyshire, and Craven 

 in Yorkshire, rise to the height of about two thousand feet above the 

 present level of the sea. They contain through their whole extent, 

 fossil remains of zoophytes and marine animals, but more abundant- 

 ly in some parts than in others. Particular species occupy almost 

 exclusively distinct beds, and in some situations the whole mass ap- 

 pears a compact congeries of mineralised organic remains. Over 

 these vast beds of ancient limestone occur a series of sandstone stra- 

 ta and shale, containing, almost exclusively, remains of terrestrial 

 vegetables associated with beds of coal. Above this series we meet 

 with other calcareous strata, contaijiing remains of fish and enor- 

 mous reptiles of the saurian or lizard tribe, intermixed with numerous 

 species of bivalve and univalve shells, but of different genera or 

 species from those living in the present seas. Again, in the upper- 

 most or tertiary strata, we meet with bones and teeth of land quad- 

 rupeds of the class Mammalia, some of which belong to unknown 

 genera, and nearly all to unknown species. Among these are the bones 

 of large animals as the mastodon, the elephant, the rhinoceros, the 

 hippopotamus, and the gigantic tapir. These large animal remains 

 occur chiefly in beds of clay or gravel, or in caves, in the latter 

 situation, they ai e abundantly mixed with bones of smaller quadru- 

 peds, of v/hich the species no longer exist in England. 



The calcareous mountains of the Jura, and the outer range of the 

 Alps, contain beds filled with the remains of marine animals, many 

 of which I have examined, and found to be similar to those in the 

 secondary strata in England. In the Alps they occur at the height 

 of from six to eight thousand feet. Similar phenomena are obser- 

 ved in the calcareous mountains of the Pyrenees ; and according 

 to Humboldt, organic remains occur in the Andes, at the height of 

 fourteen thousand feet. The distinct characters of the animals found 

 in the upper and lower beds in these mountains, as well as in those 

 of our own country, prove that they were not brought into their 

 present situation by any sudden inundations, which would have mix- 

 ed different orders of animals together. The beds which contain, 

 exclusively, the remains of animals of the same species must have 

 remained, for ageSj under the ocean ; for these animal remains often 



