Ragnarok : the age of fire and gravel

52 THE DRIFT.

radiating southwestwardly from Lake Superior, as if that was the seat of the disturbance which caused them.” *

Moreover, when we come to examine the face of the rocks on which the Drift came, we do not find them merely smoothed and ground down, as we might suppose a great, heavy mass of ice moying slowly over them would leave them, There was something more than this. There was something, (whatever it was,) that fell upon them with awful force and literally smashed them, pounding, beating, pulverizing them, and turning one layer of mighty rock over upon another, and scattering them in the wildest confusion. We can not conceive of anything terrestrial that, let loose upon the bare rocks to-day, would or could produce such results.

Geikie says :

“ When the ‘till’ is removed from the underlying rocks, these almost invariably show either a well-smoothed, pol-

ished, and striated surface, or else a highly confused, broken, and smashed appearance.” +

Gratacap says :

“< Opushed ledges’ designate those plicated, overthrown, or curved exposures where parallel rocks, as talcose schist, usually vertical, are bent and fractured, as if by a maullike force, battering them from above. The strata are oftentimes tumbled over upon a cliff-side like a row of books, and rest upon heaps of fragments broken away by the strain upon the bottom layers, or crushed off from their exposed layers.” {

The Rey. O. Fisher, F. G. 8., says he

“Finds the covering beds to consist of two members —a lower one, entirely destitute of organic remains, and

* “ Geological Survey of Wisconsin, Iowa, and Minnesota,” p. 147. + “The Great Ice Age,” p. 73. + “Popular Science Monthly,” January, 1878, p. 326.