Ragnarok : the age of fire and gravel

WAS IT CAUSED BY GLACIERS? 19

the moraine profonde in their softness, and the large area which they cover. Strata of bowlder-clay at all comparable to the great clay mantle covering the lower grounds of Britain, north of the Thames, are conspicuous by their absence from the glaciated regions of Central Europe and the Pyrenees, which were not depressed beneath the sea.” *

A River issuise From a Swiss Gracie.

Moreoyer, the Drift, especially the “ till,” lies in great continental sheets of clay and gravel, of comparatively uniform thickness. The glaciers could not form such sheets ; they deposit their material in long ridges called “terminal moraines.”

Agassiz, the great advocate of the ice-origin of the Jrift, says :

“ All these moraines are the land-marks, so to speak, vy which we trace the height and extent, as well as the

* Dawkins’s “Early Man in Britain,” pp. 116, 117.