Some Salient Points in the Science of the EarthDawson, John William, Sir
Science
Some Salient Points in the Science of the Earth
Dawson, John William, Sir
Geology; Paleontology
Here, however, a more modern feature attracts our attention. The sides
of the bounding hills are cut in a succession of terraces, rising one
above another from the level of the sea to a height of 500 feet or
more, capped with long ranges of the white houses and barns of the
Canadian habitants, and furnishing level lines for the "concession
roads" which run along the coast. These terraces are really old sea
margins indicating the stages of the elevation of the land out of the
sea immediately before the modern period. On these terraces, and in the
clays and sands which form the plateaus extending in some places in
front of them, are sea shells of the same kinds with those now living
in the Gulf of St. Lawrence, and occasionally we find bones of whales
which have been stranded on the old beaches.
These terraces are, of course, indications of change of level in very
modern times. They show that in what we call the Pleistocene age the
land was lower than at present, and we shall find that in the Lower
St. Lawrence there is evidence of a depression extending to over 1,000
feet, carrying the sea far up the valley, so that sea shells are found
in the clays as far up as Kingston and Ottawa, and stranded skeletons
of whales as far west as Smith's Falls, in Ontario.
If we examine the shores more minutely, we shall find all along the
south coast a belt of boulders which are often as much as eight to ten
feet in diameter, and consist largely of rocks found only in the hills
of the northern coast, more than thirty miles distant, from which
they must have been drifted to their present position. This boulder
belt, which extends from the lowest tide mark about fifty feet or
more upward, is sometimes piled in ridges and sometimes flattened out
into a rude pavement. It is a product of the modern field ice, which,
attaining a great thickness in winter, has boulders frozen into its
bottom, and floating up and down with the tide, deposits these on the
shore. At Little Metis, two hundred miles below Quebec, where I have a
summer residence, I have from year to year cleared a passage through
the boulder belt for bathing and for launching boats, and nearly every
spring I find that boulders have been thrown into the cleared space
by the ice, while one can notice from year to year differences in the
position of very large boulders.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account