1887] Geology and Paleontology. 269 
The landslide was due not to any undermining of the bluff, as 
the inclination of its lower part was at too low an angle, and the 
river two or three hundred feet away, but due to the hydrostatic 
pressure acting in the joints and along the smooth bedding of 
ratory experiment on plications, twistings,’and thrusts, as shown 
in folded schistose rocks of mountain regions.—/. W. Spencer, 
University of Missouri, Columbia, Mo. 
- Age of the Niagara River.—The visit in August last of the 
Geological Section of the American Association to St. David’s 
Valley,—adjacent to the Whirlpool of the Niagara River,—has 
drawn forth some notes upon this subject in the i issues of Science 
for September 3 3 and 10, 1886. 
In my various arietes bearing upon the origin of the Great 
Lakes,—the most recent of which appeared in “ Surface Geology 
of the Region about the Western End of Lake Ontario,” Cana- 
dian Naturalist, 1882, —after having shown that the deep west- 
ern end of Lake Ontario was due to subaerial erosion and streams, 
—among which was a great river flowing from the Erie Basin, 
with large tributaries from the highlands of the province of On- 
tario, cutting a cafion through the thick beds of limestones and 
shales of the Niagara escarpment to a depth of nearly one thou- 
sand feet—now partly submerged beneath Lake Ontario—and a 
width of over two miles,—I accounted for the drift-filled valley 
of St. David as being a portion of a channel of an interglacial 
Niagara River. 
Subsequent observations of Dr. Julius Pohlmann (Proc. A. A. 
A. S., 1882) show that the eastern end of the Erie Basin is due 
to erosion by streams,—some of whose channels are now deeply 
buried near Buffalo —which emptied into the Alleghany River, 
as it flowed northward from near Dunkirk, into the western end 
of Lake Ontario by the Dundas Valley. This great ancient 
water-way is now partly filled with drift, and is still more ob- 
scured by the warping of the rocks along the anticlinal between 
the two Great Lakes. 
Upon further examination it will be found that the St. David’s 
Valley is small, not only when compared with the great (Dundas) 
valley, —the old outlet of the Erie Basin, —but even with man 
other valleys cutting into the Niagara escarpment. Again, Pro- 
fessor Claypole’s observation that rocks are found beneath the 
talus at a considerable height along the sides (at least) of the 
ath valley at the Whirlpool, restriéts still more its. probable 
h. In short, the St. David’s Valley is inadequate for the 
drainage of a great basin like that of Lake Erie. | 
