Wa eier nn =~ sieges si = 
MERWIN: SHORE-LINES. 311 
on the east by the high ridge of the Green Mountains, and on the west 
by the Adirondack Mountains; at the south it narrows and merges 
into lowlands of a similar character in the middle Hudson valley; 
at the north it is continuous with the thousands of square miles of 
almost dead level clay plains south of the St. Lawrence River. 
Above the plains in Quebec several igneous stocks rise. Brome 
Mountain and Shefford Mountain are two such stocks situated about 
25 miles north of Vermont. Below the level of the plains there is an 
area extending the entire length of northwestern Vermont which was 
not completely filled to the general level by glacial deposits. This 
area is occupied by Lake Champlain. The surface of the lake is 
96 feet above the sea, according to Gannett’s (1906) Dictionary of 
altitudes. 
THE SHORE-LINES. 
PROBLEMS STATED.— The problems in mind when this study was 
begun may be stated as follows: — 
1. What evidences are there of abandoned Pleistocene shore-lines 
on the eastern side of the Lake Champlain drainage basin? 
2. Are such shore-line features as may be found, associated with 
local bodies of water, or may they be correlated with shore-lines already 
made out in the western part of the Champlain district ? > 
3. Did any of the Pleistocene lakes which once occupied valleys 
now draining westward into Lake Champlain drain eastward into 
the Connecticut River? 
Previous Stupres.— C. H. Hitchcock and others (61, p. 93-191) 
early mapped and described many terraces and so-called shore-lines 
of northwestern Vermont. Later, Baldwin (94) studied some of the 
evidences of submergence along the eastern shore of Lake Cham- 
plain, and Chalmers (98, p. 12-19) makes reference to beaches in 
southeastern Quebec. Woodworth (1905) has brought together the 
results of his own observations and those of others in the Lake 
Champlain district. I give here a summary of the history of the 
body of water which occupied the valley of Lake Champlain during 
the retreat of the Wisconsin ice-sheet, as such history has been 
sketched by Woodworth. 
While the southern end of the ice-tongue which occupied the Cham- 
plain valley stood in the vicinity of the present divide between the 
Champlain and Hudson valleys, a body of fresh water known as Lake 
Albany bordered the ice-tongue, and d rained southward. At a later 
time the waters of the southern part of Lake Albany were drained 
away, but the waters of the northern part were held in at a lower level 
than the original level by a barrier across the basin near Schuylerville, 
