GLACIAL PHENOMENA IN THE ADIRONDACKS 405 
Mohawk valley at either extremity, while a feebler current, at the height of 
glaciation, probably passed over the Adirondacks and gave to the whole a 
southerly trend. 
The detailed work of Brigham has already proved the accu- 
racy of this general statement for the Mohawk valley. The data 
gathered for the present paper tend to show its truth as regards 
the Adirondack area. 
GLACIAL DEPOSITS. 
The glacial deposits of the Adirondacks belong to the time 
On retreat and melting of the ice. Very little true morainal 
material is found, whereas stratified drift is abundant. The 
reason for this condition is evident ; during the time of maximum 
advance of the ice the Adirondacks were so far from the border 
as to be within the area where movement was too vigorous for 
deposition ; such deposits as there are belong to the time when 
the melting ice afforded opportunity for the deposition of its 
drift in bodies of water. Lake Champlain is the shrunken rem- 
nant of a large body of water’ which occupied the depression, 
while ice still stood in the St. Lawrence valley. Shore deposits 
were laid down along the border of this lake, while mud was 
laid down farther out in its waters. Large deltas were formed 
at the mouths of the streams. With the further retreat of the 
ice to the north, the waters of this lake subsided, and the shore 
deposits and deltas were formed farther and farther out, succes- 
sively overlapping on the clays of the preceding stage.* During 
a part of this period the Champlain valley was an arm of the 
sea, some of the sands and clays containing marine fossils. 
On the great plain to the north true morainal material is 
found, though sparingly. The plain is overlain by a succession 
of sand plains at various levels. Deltas are numerous. The 
complete history of these successive stages has not been 
attempted, nor their correlation with the Champlain deposits. 
™T ake Hudson-Champlain,” See WARREN UPHAM, Gzl/. Geol. Soc. Amer., Vol. 
III, 1891. 
7H. P. CusHINe, ‘Geology of Clinton County,” Fifteenth Ann. Rept. N. Y. State 
Geologist. 
