Pleistocene of the Champlain Valley. — Baldwin. 181 
.sand terraces, is seen, in which the river meanders through a 
wide flood-plain, avoiding a recently deserted channel Cor a 
long bend to the north. From the quarry north, the lime- 
stone ledge is everywhere near the surface, except for the 
small gorge, not more than 30 to 40 feet wide and perhaps 75 
to 100 feet deep, which has been cut in the hard limestone by 
the present river. After a second turn south the river emerges 
again into the broad valley limited by sand terraces. Only a 
short distance south of tins gorge is a sand terrace, standing 
exactly across the broad valley, continuous with the terraces 
of the south side of the valley, and containing no rock to at 
least the depth of the present river. The top of this. terrace 
is lower than the top of the limestone gorge. Evidently the 
river has required the same time to clear out the broad valley 
above and the rock gorge, and both are measures of the time 
since the sea fell below the 240 feet level, that of the top of 
the terrace. 
Moraines. 
Professor Hitchcock has shown that moraines of recession 
can be traced in the mountainous New England states, 
although with more difficulty than on the western plains. 
He alludes to a great moraine crossing Vermont from Wil- 
loughb} r lake, along the upper La Moille, to Burlington.* I am 
inclined to think that this moraine passes through Hyde 
Park and Cambridge to Underbill, but not to Burlington, for 
the buried deposits of Milton seem to indicate that it bends 
to the north near the lake and crosses it, to be represented in 
New York by the extensive deposits of Beekmantown, south- 
ern Altona, and Dannemora. Another line of exceptionally 
abundant drift deposition seems to pass through Ripton, also 
bending northward near the lake, through Middlebury and 
Addison. A third morainic line seems to pass just south of 
the lake and to continue west across the south end of Lake 
George. 
History of the Champlain Valley. 
The Champlain Hirer. The great depth and the form of 
the Champlain valley, as a valley of erosion, indicate a long 
continued preglacial elevation of at least 500 feet for this en- 
tire region. During that time the valley was occupied by a 
*Proc. A.' A. A. S., vol. xli, for 1892, p. 175. 
