J. C. Smock—Thickness of the Continental Glacier. 347 
see it. In this way the moraines were partly destroyed. 
Ascending these valleys to their head, the upper limits of the 
thick drift masses are reached, beyond which, on.the steeper 
mountain slope, the explorer finds the evidences of glaciation 
in roches moutonnées and scattered bowlders on y: e 
heights of these moraine limits vary somewhat :n the different 
valleys. Thus, at the head of the Batavia Kill Valley and 
hear Black Dome, it is about 2700 feet; west of the Catskill 
Mountain House, and near Tannersville, it is at least 2000 feet ; 
on the northern slope of Hunter Mountain it is 2200 feet; in 
the Stony Clove Notch it is about 2000 feet ; in the notch west 
of Slide Mountain, and at the headwaters of the Neversink, it 
is 2650 feet; near Summit Station, on the U. & D. railroad 
line, it is 2200 feet; near Margaretville, 2000 feet; on the 
Southeast slope of Mt. Pisgah, northwest of Margaretville, it is 
0 feet; and near Stamford, at the head of the west branch 
of the Delaware, it is 2000 feet. Of course, it will be under- 
Stood that these thicker glacial deposits are, to a great extent, 
determined by the configuration of the rocky floors or valleys 
in which they were deposited, and their elevation is, therefore, 
®pproximately that of these valleys. But, inasmuch as the 
slopes rise much higher, affording surface for deposition at 
greater altitudes, it is probable that the average of these eleva- 
tions, from 2000 to 2800 feet, was the upper limit of the 
moraine profonde, or till. The scratched ledges, sub-angular 
bowlders and gravel, and the glacial earth, which lie on the 
higher slopes, indicate that the ice encountered the more ele- 
vated mountain sides and left its marks upon them. And this 
Sparse drift was, doubtless, from the upper surface of the gla- 
“er. In order to ascertain the thickness of the ice the heights 
of these higher markings and deposits must be found. An 
here it should be stated that the examination of the higher 
may be given in the following order: 
Sex meal it the outcropping rocks are more abrupt and pre- 
Cipitous, even on the north slopes, and there are no marks o 
any abrading or polishing am No roches moutonnées have 
been discovered on these higher peaks and slopes. 
