MODIFIED DRIFT ALONG CONNECTICUT RIVER. 2/ 



The most extensive intervals or meadows are between Woodsville and 

 Bradford, Vt., 12 miles long and one half to one mile wide, including the 

 Lower Coos intervals of Newbury, Vt., Haverhill, and Piermont ; and in 

 Charlestown and Rockingham, Vt., 6 miles long and half a mile wide. 

 But, in addition to these, smaller areas, up to a mile or more in length 

 and a few rods to a half mile wide, are of common occurrence along the 

 entire valley. These bottom-lands are very fertile, being composed of 

 the finest silt, and enriched every year by a coating of mud from the 

 turbid freshets of spring. Many of the lower terraces which are not 

 overflowed are of the same material; but the higher terraces usually 

 show some intermixed sand or fine gravel. 



These lateral terraces are less plainly continuous in extent and height 

 than the intervals or the upper terrace. They are sometimes numerous, 

 again wanting; seldom agreeing in height on opposite sides; usually 

 showing a slight slope with the river, but not often more than one or two 

 miles, and generally less than one mile in length, and succeeded by others 

 higher or lower. An examination of them over long distances, however, 

 sometimes shows a well-marked series, descending with the river, and 

 recording a height at which, during the process of erosion, it remained 

 nearly stationary for an unusual length of time, forming a broad and 

 continuous flood-plain, now interrupted and mainly swept away by the 

 further deepening of the channel. These terraces are almost always 

 level-topped, and bounded at the face by a steep escarpment ; and their 

 appearance is sometimes very striking, and even grand, as they rise in 

 gigantic steps on the side of the valley, shaped with a smoothness, 

 order, and beauty which could not be surpassed by art. 



The greatest widths of modified drift that can be measured in this 

 valley, on the west side of New Hampshire, are in Haverhill and 

 Newbury, two miles, and in Hinsdale and Vernon, two and a half miles 

 wide. The average width is fully one mile. The narrowest places are 

 at Shaw's mountain, near the south line of Bradford, Vt., and at Barber's 

 mountain, in Claremont, both of which occupy the middle of the valley, 

 with narrow belts of alluvium on each side ; at the west side of Rattle- 

 snake hill, Charlestown ; and at the south end of Wantastiquit mountain, 

 below Brattleborough, Vt. We do not discover, however, at these places, 

 or elsewhere, any evidence of former barriers, which could have made the 



