chap. vi.
GLACIER VERSUS ROCKS.
141
nature is changed; it operates in a different way, and it leaves marks which are readily distinguished from those produced by torrent-action.
The prevailing forms which result from glacier-action are more
STRIATIONS PRODUCED BY GLACIER-ACTION (AT GRINDELWALD). |
or less convex. Ultimately, all angles and almost all curves are obliterated, and large areas of flat surfaces are produced. This perfection of abrasion is rarely found, except in such localities as have sustained a grinding much more severe than that which has occurred in the Alps; and, generally speaking, the dictum of the veteran