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 moving 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, polished, and striated
surface, or else a _highly confused, broken, and smashed_
appearance."[2]

Gratacap says:

"'_Crushed ledges_' designate those plicated, overthrown, or curved
exposures where parallel rocks, as talcose schist, usually vertical,
are bent and fractured, _as if by a maul like 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."[3]

The Rev. O. Fisher, F. G. S., says he