MODIFIED DRIFT ALONG CONNECTICUT RIVER. 35 
with regular strata of sand exposed for several feet both above and below, 
was seen on the north side of a cart-road which ascends the east bluff of 
the Fairlee plateau, opposite the house of William Childs. 
The shores of Fairlee pond are mostly rugged ledgy hills, and scarcely 
any alluvium has reached them, either from the plateau of Jacob's brook 
or from inflowing 
streams. This 
pond is 35 feet 
above the river, 
and is from 40 Fig. 6.—FoLDED LAYER OF CLAY IN HORIZONTALLY STRATI- 
to 45 feet in its FIED SAND, FAIRLEE, VT. Scale, 1 inch—=10 feet. 
greatest depth, the bottom being principally sand. It seems not to have 
been filled with alluvium, simply because it was not in the path of the 
current; and the steep escarpment of the plain bordering its south end 
is probably due to its undermining waves. Several glacis terraces were 
noted south-west of Ely station. 
In Thetford and Lyme we come to an abrupt change in the height of 
the upper terrace-plain. We have seen this line descend, in 33 miles 
between the mouth of Passumpsic river and the south line of Orford, 
from 650 to 440 feet above the sea, gradually declining from 190 to only 
60 feet above the river. At North Thetford this line of the highest ter- 
race suddenly rises to 525, and in a mile and a half farther south to 545 
feet. This formation is well shown through Thetford, with remnants in 
Lyme, and continues well developed and nearly level for twenty-five miles 
to Windsor, varying from 560 to 500 feet above the sea, and from 150 to 
220 feet above the river. It forms extensive terraces or plains on one 
or both sides along this whole distance, and is clearly the original flood- 
plain of the river. Frequent delta-terraces rise above it, sometimes 100 
feet higher, being more than 300 feet above the present river channel. 
It is a notable coincidence, that along this same distance we have a con- 
tinuous kame, occupying the centre of the valley, commonly rising some- 
what above the highest plain, but not seldom entirely covered by it. 
Superposition and conformable stratification show the fine material of 
the terrace-plain to have been deposited upon this kame or gravel ridge, 
which beforehand extended like a windrow along the empty valley. To 
the south from Windsor the highest terrace shows a somewhat regular 
