Rushin—WNotes on the Denudation of the Alps. 53 
is of importance in relation to many of the foliated precipices of 
the Alps, in which it is difficult to distinguish whether their 
vertical cleavage across the beds is owing merely to disinte- 
gration and expansion, or to faults. In all cases of strata 
arched by elevation, the flank of the arch (if not all of it) must 
be elongated, or divided by fissures. The condition, in abstract 
geometrical terms, is 
shown in fig. 4. If ap 
was once a continucus 
bed, and the portion c D 
is raised to E F, any con- 
necting portion, B C, will i 
become of the form B EB; 
and in doing this, either 
every particle of the 
rock must change its 
place, or fissures of 
some kind establish 
themselves. In the Al- 
pine limestones, I think 
the operation is usually 
as at GH; but in the 
Saléve the rock-struc- 
ture is materially alter- 
ed; so much so that I 
believe all appearance of fossils has been in portions obliter- 
ated. The Neocomian and the Coralline Jura of the body of the 
hill are highly fossiliferous; but I have scrambled among these 
vertical cleavages day after day in vain; and even Professor 
Favre renders no better account of them.* 
The whole ridge of the mountain continues the curve of 
the eastern shore of the Lake of Geneva, and turns its. 
rounded back to the chain of the Alps. The great Geneva 
glacier flowed by it, if ever, in the direction of the arrows 
-from X to Y in fig. 1; and, if it cut it mto its present 
shape, turned very sharply round the corner at c! The 
great Chamonix glacier flowed over it, if ever, in the direc- 
tion of the arrows from x to Y infig. 2. It probably never 
did, as there are no erratic blocks on the summits, though 
many are still left a little way down. But whatever these 
glaciers made of the mountain, or cut away from it, the 
existence of the ridge at all is originally owing to the elevation 
of its beds in a gentle arch longitudinally, and a steep semi- 
Fig. 4.—Diagram of Upheaved Beds. 
* ‘Considérations sur le Mont Saléve,’ Geneva, 1843, p. 12. 
