“The lower bed of the drift is entirely destitute of organic remains."
Sir Charles Lyell tells us that even the stratified drift is usually devoid of fossils:
“Whatever may be the cause, the fact is certain that over large areas in Scotland, Ireland, and Wales, I might add throughout the northern hemisphere, on both sides of the Atlantic, the stratified drift of the glacial period is very commonly devoid of fossils."
[1. “Great Ice Age,” Geikie, p. 7.
2. Ibid., p. 9.
3. Ibid., p. 342.
4. Rev. O. Fisher, quoted in “The World before the Deluge,” p. 461.
5. “Antiquity of Man,” third edition, p. 268.]
In the next place, this “till” differs from the rest of the Drift in its exceeding hardness:
“This till is so tough that engineers would much rather excavate the most obdurate rocks than attempt to remove it from their path. Hard rocks are more or less easily assailable with gunpowder, and the numerous joints and fissures by which they are traversed enable the workmen to wedge them out often in considerable lumps. But till has neither crack nor joint; it will not blast, and to pick it to pieces is a very slow and laborious process. Should streaks of sand penetrate it, water will readily soak through, and large masses will then run or collapse, as soon as an opening is made into it.”
with bowlder-clay, river STINCHAR.
r, Rock; t, Till; g, Bowlder-Clay; x, Fine Gravel, etc.
The accompanying cut shows the manner in which it is distributed, and its relations to the other deposits of the Drift.
In this “till” or “hard-pan” are found some strange and characteristic stones. They are bowlders, not water-worn, not rounded, as by the action of waves, and yet not angular—for every point and projection has been ground off. They are not very large, and they differ in this and other respects from the bowlders found in the other portions of the Drift. These stones in the “till” are always striated—that is, cut by deep lines or grooves, usually running lengthwise, or parallel to their longest diameter. The cut on the following page represents one of them.
Above this clay is a deposit resembling it, and yet differing from it, called the “bowlder-clay.” This is not so tough or hard. The bowlders in it are larger and more angular-sometimes they are of immense size; one at
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