134 SANDS. 



fieial, varying in depth from a few inches to 80 or 90 feet, and in general have a regular and nearly 

 horizontal stratification. They usually terminate downward in brown or blue clay, and in many places the 

 mixture of clay and sand is in the proper proportion for making bricks, as at the foot of Winooski Falls. 

 The elevation of the surface of these sand deposits varies from 20 to 260 feet above Lake Champlain. 

 The mean elevation of those plains (terraces) to the westward of the range of [Winooski] limestone, 

 extending from Lonerock Point to Mallett's Head, and thence to Milton, may be estimated at 40 feet ; and 

 the mean elevation of the extensive sandy plains commencing in Burlington, and extending through the 

 southwestern part of Essex, and through the central parts of Colchester and Milton, is about 200 feet. 

 Marine shells are found in this sand in numerous places. At one place in Burlington, half a mile northeast 

 from Lonerock Point, and by the side of the road, they abound in a coarse gravel about 130 feet above the 

 lake ; and two miles northeast of Mallett's Bay in Colchester, is a large deposit of them at an elevation 

 of more than 200 feet above the lake. At both these places they are much broken, and mingled 

 with rather coarse gravel. It would appear in these places, that the shells had been worked up above the 

 line of the shore composed of drift, and that the gravel of the drift [terrace materials] was mingled with 

 them by the action of the waves, and [these and larger objects like the fossil] whales were at length buried 

 by the washing down of the drift materials." 



We would also quote further remarks by Prof. Thompson, derived from the same manuscript. We will 

 not alter any of the terms which he used, and will say, in respect to them, that the drift spoken of is obvi- 

 ously what has been designated in this Report as Modified Drift, and that the pleistocene deposits are the 

 same things that we have denominated Terraces. The Principal of the Survey has thought best to simplify 

 the numerous deposits of alluvium by denominating them Drift and Modified Drift, instead of the terms 

 Newer and Older Pleiocene and Pleistocene, as used by Adams and Thompson. The former term applies 

 to a tertiary deposit now found in the State. 



"The term drift, when distinguished from the pleistocene sands and clays, is generally, 

 I believe, understood to denote an older deposit, consisting of sand, clay, gravel, pebbles 

 and bowlders, thrown together in great disorder, rarely exhibiting very distinct signs of 

 regular stratification ; and the appearance and situation of the drift in this county are for 

 the most part conformable to this opinion. Still, however, there are some apparent 

 exceptions. There are frequently deposits of what I should not hesitate to call pleisto- 

 cene sand and clay, which are covered with deposits of what I should with equal confi- 

 dence call drift materials. But these cases, if carefully examined, are not calculated to 

 impair our confidence in the general opinion that the drift formation is older than the 

 pleistocene. It will generally be obvious, that although materials of the drift period are 

 lying upon the pleistocene deposit, they have been brought into that condition by the 

 action of the waters of the pleistocene period. These are usually upon the side, or at the 

 foot of a hill composed of drift materials, and it is easy to conceive that while this hill 

 formed an island in that arm of the ocean which occupied the valley of Lake Champlain 

 in the pleistocene period, the action of the waves upon the shores of this island might 

 wash down the drift materials of which it was composed, and spread them out upon the 

 stratified clay and sand previously deposited. 



"This matter is wej.1 illustrated by the elevation upon which the village of Burlington is 

 located ; or rather some phenomena are here exhibited, which it is difficult to understand 

 upon any other hypothesis. All the lower part of the village stands upon a deep deposit 

 of pleistocene sand and clay, which is in general very regularly stratified. This deposit 

 extends eastward, becoming gradually more elevated in departing from the lake. At the 



