444 ON THE GEOLOGY OF THE 



careous cement, but fastened, as they are in the ocean, to the 

 soil on which they grow. 



From these facts, it seems to be quite evident, that these 

 shells must have been deposited at different periods, during 

 the tardy formation of the gravel heaps in which they are im- 

 bedded ; and also, that the heaps must have required a long 

 time for their accumulation, not only from the growth of the 

 beds of shells, but from the nature of the materials of which 

 the hills are composed, and the distance from which these have 

 been transported. When we consider the time required for 

 the destruction of the original rocks, and for reducing them 

 to their present state, it carries the mind back to a period, 

 compared to which that of history is but a trifle. In the whole 

 of these operations, we see no marks of hurry and confusion, 

 no trace of those convulsions which must have preceded 

 them, previous to the formation of the Mediterranean marble. 

 On the contrary, from the disposition of the materials them- 

 selves, and from the extreme delicacy, and state of perfection 

 in which many of the shells have been found, there is next to 

 a positive proof, that the accumulation must have proceeded 

 with the utmost tranquillity, and that these heaps of gravel 

 must have been carried gradually down, and quietly deposited 



in the sea. 



The shape which they present is also analogous to the na- 

 ture of the beach in the vicinity of Nice, which, though compo- 

 sed of loose pebbles, is remarkably shelving, and the sea be- 

 comes suddenly very deep. Saussure states, that only a league 

 from the shore, he found 1800 feet of water. Hence, supposing a 

 further depression of the Mediterranean, we should just have 

 such another series of steep acclivities as the gravel banks now 

 present, the sides and extent of which would in time be fur- 

 rowed and indented by the running of torrents. 



There 



