^ SCATTERED BLOCKS OF GRANITE NEAR GENEVA. 355 



Great and Little Saleve, in the immediate vicinity of that city. 

 They present their steep escarpments of limestone to the valley of 

 the Rhone, but slope down on the south side to the valley of the 

 Arve. On this southern side may be seen, not the remains of an 

 ancient temple or city, but the magnificent ruins of mighty mountains 

 and the monuments of an overwhelming catastrophe, which trans- 

 ported these ruins into their present situation. The snow-clad moun- 

 tains from which they were torn rise magnificently to the view, 

 though fifty miles distant. On the Little Saleve, at the height of 

 fourteen hundred feet above the valley, are scattered numerous 

 blocks of granite of vast size, not at all water-worn, and almost as 

 fresh as if recently torn from their parent mountains ; they are of 

 that kind of granite called Protogene, in which talc or chlorite is one 

 of the component parts, and are identical with the granite of Mont 

 Blanc, while the Saleve on which they lie, and the surrounding 

 mountains are calcareous. On the Great Saleve adjoining, there is 

 one block of this granite seven feet in length, and at the height of 

 2500 feet above the valley. Saussure has remarked, that these 

 blocks are not broken or shattered as they would have been, had 

 they been hurled with violence from the Alps; neither do the lime- 

 stone strata beneath them present any appearance of having been 

 fractured or indented by their fall : on the contrary the blocks lie 

 upon the surface. Two of these blocks of granite rest upon pedes- 

 tals of limestone, a few feet above the general level of the ground. 

 The blocks have evidently protected the limestone beneath them 

 from disintegration, and thus would serve as chronometers, to indi- 

 cate the period when they were deposited, could we ascertain the 

 thickness of surface worn away in a given time. 



I observed a few of the blocks were cracked, but this was, in all 

 probability, effected by the percolation of water, and its expansion 

 by frost. Another circumstance pointed out by Saussure is, that 

 ' these blocks, in their passage from the Alps, appear to have taken 

 the course of the present valleys, and where they have been carried 

 as far as the Jura chain, they rest at various heights on the sides of 

 ; that range of mountains, exactly opposite to the mouths of the Alpine 

 valleys. Saussure, however, supposes, and with much probability, 

 that the whole of the valley of Geneva, and the valleys that run 

 from the Alps, and all the lower mountains of Savoy, were covered 

 by the sea at the period when the great catastrophe took place, and 

 that the rocks were torn off, and transported by a sudden rush of wa- 

 ters. He further supposes, that the specific gravity of the blocks 

 being diminished by the medium in which they were borne along, 

 they might be carried to a great distance by the violence of the cur- 

 rent, and deposited at considerable altitudes. The floating of Al- 

 pine glaciers loaded with fragments of rock, would perhaps better re- 

 move the difficulty attending the explanation of these occurrences 

 at the height of fifteen hundred feet and more above the valleys. 



