SCRATCHED STONE (BLACK SHALE), FROM THE TILL.
Bradford, Massachusetts, is estimated to weigh 4,500,000 pounds. Many on Cape Cod are twenty feet in diameter. One at Whitingham, Vermont, is forty-three feet long by thirty feet high, or 40,000 cubic feet in bulk. In some
{p. 7}
cases no rocks of the same material are found within two hundred miles.[1]
These two formations--the "till" and the "bowlder-clay"--sometimes pass into each other by insensible degrees. At other times the distinction is marked. Some of the stones in the bowlder-clay are furrowed or striated, but a large part of them are not; while in the "till" the stone not striated is the rare exception.
Above this bowlder-clay we find sometimes beds of loose gravel, sand, and stones, mixed with the remains of man and other animals. These have all the appearance of being later in their deposition, and of having been worked over by the action of water and ice.
This, then, is, briefly stated, the condition of the Drift.
It is plain that it was the result of violent action of some kind.
And this action must have taken place upon an unparalleled and continental scale. One writer describes it as,
"A remarkable and stupendous period--a period so startling that it might justly be accepted with hesitation, were not the conception unavoidable before a series of facts as extraordinary as itself."[2]