MERWIN: SHORE-LINES. 329 
the Wisconsin ice from the region, the heads of the valleys were first 
freed of ice. Marginal lakes then collected between the ice-front and 
the divides. The first lakes to form were at the head branches of the 
Winooski River. Each of them for a brief time spilled over into the 
Connecticut River drainage. The last marginal lake in the Winooski 
valley to abandon the Connecticut River drainage was a small one 
north of the 890-foot divide near Williamstown. This happened 
before the lakes in the branch valleys had become confluent, and 
from this time drainage took place beneath or around the ice into the 
Champlain valley. As the ice withdrew further and the lakes coalesced 
the First Lake Winooski stages were entered upon. (Plate 2.) 
By this time, in the Lamoille valley, a similar lake was growing. 
At an early stage it is probable that it drained northward through 
the Lake Memphremagog basin. The stages preceding this probable 
stage have been called First Lake Lamoille, and those immediately 
succeeding, Second Lake Lamoille. 
As soon as the ice no longer obstructed the valleys east of the Green 
Mountains, First Lake Winooski and Second Lake Lamoille met in 
the longitudinal valley east of Mt. Mansfield, thus introducing the 
Lake Mansfield stage. 
Lake Mansfield came to an end when its level dropped enough to 
cause a division between the waters that occupied the Lamoille valley, 
and those which occupied the Winooski valley. This division brought 
into existence the Second Lake Winooski and the Third Lake Lamoille 
stages. 
With further retreat of the ice-tongue which occupied the western 
part of the Winooski valley, a strong discharge of glacial waters took 
place through an arm of Lake Winooski which stood high enough to 
drain across the divide east of Hollow Brook. 
Subglacial communication was soon after established between Lake 
Winooski and Lake Vermont, and then Lake Winooski dropped to 
the level of and coalesced with Lake Vermont. 
At this time the ice still obstructed the Lamoille valley. It was not 
until Lake Vermont had fallen to its Wood Creek stage that Lake 
Lamoille became directly confluent with it, first through the Brown’s 
River valley, and later through the present valley. 
