MODIFIED DRIFT ALONG CONNECTICUT RIVER. 43 



The Kamc of Contiectiad Valley. 



From Lyme to Windsor we find a continuous gravel ridge or kame, 

 extending twenty-four miles along the middle and lowest portion of this 

 valley, with its top from lOO to 250 feet above the river, or from 500 to 

 600 feet above the sea. Its material is gravel and sand, in irregular, 

 obliquely-bedded layers, always showing an inclined, and in most cases 

 a distinctly anticlinal or arched, stratification. The sand is usually coarse 

 and sharp, well suited for masons' use. It occurs in layers of varying 

 thickness up to one or two feet, but sometimes it is wholly wanting. The 

 gravel, which always forms the principal part of the ridge, varies in coarse- 

 ness, from layers with pebbles only one or two inches in diameter, to por- 

 tions where the largest measure one and a half or two feet. The finer 

 kinds prevail ; and the channels of brooks cutting through the ridge fre- 

 quently show no pebbles exceeding one foot in size. All the materials of 

 this kame, and of its remnants along this valley, are plainly water-worn 

 and stratified. 



Large and unworn boulders, which could not have been brought in the 

 same way with the gravel and sand, occur very rarely upon or in the Con- 

 necticut kame. Except at its south termination, the only instance of this 

 discovered was three fourths of a mile south of Pompanoosuc river, at 

 the point where the kame reaches its greatest height above the sea. Two 

 angular boulders, each of five feet dimension, were found here at the top 

 of the ridge, one lying on the surface, and the other partly imbedded. 

 This place was covered with a thick growth of sapling white pines. Sev- 

 eral miles at least of journey on foot along the top of this ridge, and the 

 examination of many sections where the river or its tributaries have cut 

 through it, failed to reveal other boulders of this kind. 



One or both sides of this kame are generally covered by the alluvium 

 of the upper terrace, which plainly was of later deposition ; but the top 

 usually projects in a long, rounded ridge, 10 to 30 feet above the adjoin- 

 ing highest plain. At one place, east of Hartland depot, this plain has 

 been swept away from both sides, and the kame forms a conspicuous, 

 steep ridge 125 feet in height. Wherever it is exposed, it is readily rec- 

 ognized by the pebbles which strew its surface, and which are very rarely 

 found in the ordinary modified drift of the valley. 



