132 On the Imparlance of Geological Informal io?i, ^'C. 



to which Mont Blanc, and the western Alps belong, have the 

 oolites, the green sand, and the tertiaries ; or the upper secondary 

 rocks, and the very last deposits, previous to the diluvium or su- 

 perficial soil, lying in a disturbed manner upon their flanks ; 

 showing that the mountains, having moved all the other beds, 

 were upraised since the tertiaries were deposited. Hence, we 

 come, by a fair induction, to the conclusion, that the western 

 Alps of Europe, were upraised at a diflferent period from the 

 granite hills in Leicestershire, and at a geological period, much 

 nearer our own times. To illustrate this principle, we have bor- 

 rowed from Bakewell, pi. 4, fig. 1, a section of Alpine beds, near 

 the Col de Balme, and Mont Blanc ; a, a, are alternate beds of 

 oolite, sand stone, and lias, equivalents of those horizontal beds 

 e, in pi. 4, fig. 2. ; b, b, are disturbed beds of pudding-stone, with 

 the pebbles not lying on their longest axes, but vertical ; c, c, a 

 col, or passage excavated in the soft slate of the mountains; d, d, 

 vertical plates of granite beds, with pyramidal caps, called 

 aiguilles, or needles. The dotted lines mark the supposed original 

 prolongation of the beds, before the granite came up, bearing 

 them like drapery on its flanks, where they lie at an inclination, 

 varying from G5° to 80°. Mont Blanc is 15,534 feet high, and 

 these pyramidal peaks, which time, and the deluges consequent 

 upon their upraising, have worn into their present forms, were 

 once 10,000 feet beneath the surface. Thus we have the proofs, 

 that the lias formation in England, was deposited subsequent to 

 the upraising of the granite at Charrwood forest ; and that the 

 Pennine Alps were raised subsequent to the deposition of the 

 lias. 



Since the crust of the earth, with the exception of the igneous 

 rocks, is composed of a series of beds, that have been deposited 

 in succession to each other, it results, that chains of mountains, 

 and table lands, may have been upraised at any of the periods 

 belonging to this succession, and that each period may have its 

 peculiar system of mountains. This, to a great extent, has been 

 found to be the case, and we can thus distinguish their geologi- 

 cal periods, not in the chronologies affecting the present order of 

 nature, but in the great history of subterranean dynamics, to 

 which the surface of the earth owes its present form, modified, 

 as it no doubt has often been, by the action of the waters, which 

 have been displaced by these elevations. The practical uses, 



