56 SURFACE GEOLOGY. 



kame (p. 48); and on the south side an interesting series of secondary 

 terraces, left as bench-marks of its progress in excavating the basin. 



The view of New Hampshire from Brattleborough is similar to that 

 from Bellows Falls. At both these places, the largest towns in Vermont 

 on this river, its eastern shore is an abrupt mountain wall, against which 

 no terraces or only scanty remnants are found. Wantastiquit or West 

 River mountain extends nearly four miles, with about equal portions in 

 Chesterfield and Hinsdale, and rises to an altitude about 1,200 feet above 

 the sea. The lowest point of water-shed at the east, near the head of 

 Catsbane brook, is by estimate 650 feet above the sea, or about 200 feet 

 above the highest portion of the Hinsdale plain. 



South-east and south from this mountain is the most extensive plain 

 on this river in New Hampshire or Vermont, being three miles long, 

 with a width decreasing from two miles to two thirds of a mile. The 

 road from Hinsdale to Brattleborough passes over the south end of this 

 plain. Here its height is 350 feet above the sea, or 165 above the Con- 

 necticut at the mouth of Ashuelot river. It is mainly composed of sand, 

 nearly level, but with a slight slope to the west and south, being as usual 

 towards the river and in the direction of its course. Its extremity, three 



Fig. 16.— Section in Vernon and Hinsdale. Length, 3 miles. 

 fourths of a mile south-west from this road, is twenty feet lower. North- 

 ward, its west edge is about 340 and its east side probably as high as 380 

 feet above the sea. Its northern portion changes to gravel, which be- 

 comes coarse on the south-cast side of Wantastiquit, containing pebbles 

 one foot or sometimes a foot and a half in diameter. The position and 

 slope of this plain show that it was not deposited wholly from currents of 

 the main valley ; evidently a considerable portion was contributed from 

 the melting of the ice-sheet east of Wantastiquit mountain. 



Extensive sand-drifts or dunes blown from this plain occur on the hills 

 at its cast side for a mile and a half north from Hinsdale village. The 



