Mesozoic and Cenozoic Geology and Paleontology. 43 
In Nova Scotia and New Brunswick the Bowlder clay or unstratified 
drift varies from a stiff clay to loose sand, and its composition and 
color generally depend upon those of the underlying and neighboring 
rocks. Thus over sandstone it is arenaceous; over shales, argillaceous; 
and over conglomerates and hard slates, pebbly orshingly. The great- 
er part of the stones contained in the drift are, like the paste containing 
them, derived from the neighboring formations; though, in some in- 
stances, they have been transported from a distance. The transported 
bowlders have generally been drifted southward, though some have 
been carried northward, and others in different directions. They have 
especially been drifted from the more elevated and rocky districts to 
the lower grounds in their vicinity. The stris upon the rocks vary 
from north and south to east and west, though there is a general ten- 
dency to a southern and southeastern course. 
Alfred R. C, Selwyn* found many fine examples of ice-grooves and 
scratches on the rocky shores of Vancouver’s Island, where they 
occur in different directions, and sometimes nearly at right angles to 
each other. He quoted, with approval, the statement of Prof. J. D. 
Whitney, that northern drift does not occur in California, and that no 
evidence of its occurrence has yet been detected on the Pacific coast, 
as far north as British Columbia and Alaska. This conclusion having 
been arrived at on the authority of Mr. W. D. Dall, naturalist, attached 
to the Collin’s Overland Telegraph Company, and who states that 
though he had carefully examined the country over which he had 
passed, in Alaska, for glacial indications, he had not found any effects 
attributable to such agencies ; and that no bowlders, no scratches, or 
other marks of ice action had been observed by any of his party, 
though carefully sought for. And that inland, neither Mr. Selwyn nor 
his assistant Mr. Richardson observed any. 
That the superficial deposits of British Columbia are chiefly de- 
veloped in the ancieut terraces or benches, which, throughout the coun- 
try, are wonderfully regular and persistent, occuring from the coast up 
to elevations of nearly 4,000 feet, in the passes of the Rocky mountains. 
They give a marked and peculiar character to the scenery of the river 
valleys, rising like gigantic stairs, to elevations of sometimes more than 
four hundred feet above the adjoining river or lake. In some places 
- two, three, four and five distinct steps can be seen ; while often they 
have either become merged into one by subsequent denuding agencies, 
* Geo. Sur. of Canada. 
