MERWIN: SHORE-LINES. 317 
Two miles further east, near the head of Potash Brook, a shore- 
line appears which may be traced along near the 400-foot contour, for 
3 miles. Where this shore-line reaches the hills, pockets of pebbles 
may be found in many of the small embayments. 
From 1 to 3 miles south and southeast of Essex Junction, near the 
former head of the Winooski delta, terraces at elevations of 400 to 
410 feet, and at 500 to 520 feet, overlook the deep trench which the 
river now occupies. Traces of the 400-foot level may be found on 
the low hill 2 miles west of the head of Potash Brook. 
The Lamoille Delta. Sand flats, rising from 380 feet in altitude 
near Milton to 395 feet a few miles further up the Lamoille River 
at East Georgia, and covered in places with drifting dunes and irregu- 
lar patches of gravel, give general but rather indefinite evidences of a 
water-level which falls into the plane of the upper marine limit. Mak- 
ing allowance for tilting of this plane between Milton and East Georgia, 
the water-level which determined the surface of the sand flats must 
have persisted for a long time. A number of isolated hills rise abruptly 
out of the delta. Their modifying influence on the distribution of 
currents probably had much to do with the apparent indefiniteness 
of the shore-line on the delta. No higher shore-lines were found in 
this vicinity. It may therefore be inferred that the ice still occupied 
this part of the Champlain valley when the high terraces of the 
Winooski delta and of the deltas further south were building into 
Lake Vermont. 
St. Albans Bay. Along the shores of St. Albans Bay narrow ter- 
races and wave lines occur at vertical intervals of from 5 to 20 feet up 
to the height of 150 feet above the level of the Bay. 
The Missisquoi Delta. The lowest terrace of the Missisquoi delta 
that I studied is the one at an elevation of 305 feet. Two or three 
feet below the surface of this terrace, in the gravelly top-set beds I 
found three specimens of a gastropod of an undetermined species, and 
more than one hundred valves of Macoma groenlandica. From this 
occurrence of marine shells and from occurrences elsewhere in the 
Champlain district (Woodworth, 1905, p. 208-216) it is clear that 
marine waters must have stood as high, at least, as this terrace. 
The highest point at which sands occur which I can definitely 
refer to the delta deposits of the Missisquoi River, is at an elevation of 
380 feet. This occurrence is near the railroad station at Highgate 
Centre, about 60 feet below the supposed upper marine limit at 
this place. 
There seems to be no way that the sea could have entered the 
