Feather stonhaugh's Geological Report. 67 



rocks are found at great elevations, with other beds, superin- 

 cumbent as to them in the column, hanging in an inclined state 

 on their flanks, these last having other beds still newer, 

 deposited in an undisturbed state upon their sides, that two 

 geological epochs are represented here the appearing of the 

 primary rocks through the adjacent stratified beds, and a sub- 

 sequent period of repose, during which a newer set of rocks 

 had been deposited. Wherever the beds have been thus dis- 

 located, it is evident the upheaving took place subsequent to 

 their deposite, and before the deposite of the undisturbed 

 rocks adjacent to them. This is more accurately shown by 

 the two following diagrams from nature.* In Leicestershire, 

 England, (diagram 6,) the granite, 6, &, and slate, c, c, present 

 beds highly inclined, but on the edges of those beds, new red 

 sandstone, a, a, and lias, e, are found in a horizontal position, 

 showing that these last have been deposited subsequent to the 

 upraising of the first. In the system to which Mont Blanc 

 and the western Alps belong, the primary beds have the 

 oolites, the green sand, and the tertiaries, lying in a disturbed 

 manner upon their flanks, showing that this system of moun- 

 tains was upraised since the tertiaries were deposited. Dia- 

 gram No. 7 represents a section of Alpine beds, near the Col 

 de Balme and Mont Blanc, where ft, a are alternate beds of 

 lias and oolite, the equivalents of those horizontal beds e, in 

 diagram 6 ; &, 6, are beds of pudding-stone, tilted up at a high 

 inclination, with the pebbles lying vertically, and not, as they 

 were first deposited, on their longest axes ; c, c, a col, or pas- 

 sage excavated in the soft slate of the mountains ; d, d, per- 

 pendicular plates of granitic beds, with pyramidal caps, called 

 aiguilles or needles. The dotted lines mark the supposed 

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

 on the flanks of which they lie at an inclination varying from 

 65 to 80. Mont Blanc is 15,534 feet high, and the pyra- 



* From Bake well's Geology. 



