26 SURFACE GEOLOGY. 
nothing seen in the surface geology of the valley above would require 
such a barrier. The depth of till thus removed must have been variable, 
sometimes probably amounting to 100 feet; and more or less of this exca- 
vation seems to have taken place along the entire extent of these falls. 
The irregular surface left by the ice has been thus reduced to a chan- 
nel of nearly regular slope with no abrupt falls, cut through the till, 
which still covers the ancient bed in which the river flowed before the 
glacial period. 
Lower Connecticut Valley. The early pioneers retained the Indian 
name Cods, which they found applied to the fertile intervals of Lancaster 
and Haverhill. These were the Upper and Lower Cods, separated by 
the Fifteen-miles falls. By a similar division, the whole extent below 
these falls is here called the lower valley. This is comparatively level 
and straight, with a southerly course nearly the same as that of the upper 
valley. Ina direct distance of 118 miles from:the mouth of Passumpsic 
river to Massachusetts line, the river flows 137 miles, descending from 
460 to 180 feet above ‘the sea, or two feet to the mile. The principal 
falls in this distance are Beard’s falls at Barnet, 5 feet; McIndoe’s falls, 
10 feet; Dodge’s falls, three and a half miles south, 5 feet; at Woods- 
ville, about 10 feet; White River falls, 35 feet (see map, vol. i, p. 302); 
Sumner’s or Quechee falls, two miles below the mouth of Quechee river, 
5 feet; and Bellows falls, 49 feet,—making a total of 119 feet, and leav- 
ing an average descent, excluding falls, of 13 feet per mile. 
The modified drift of this lower valley is everywhere well developed, 
and occurs in extensive terraces of various heights, three or four often 
on each side, the upper one being usually from 150 to 200 feet above the 
river, while the lowest is the interval or meadow. The largest plains are 
expanses of the upper terrace, or of still higher tributary deltas. These 
areas are generally of a clayey, moist, productive soil, quite in contrast 
with the dry sandy plains of Merrimack river, Ossipee lake, and other 
parts of the state. The nearest resemblance to these barren “pine-plains” 
is found at Woodsville, in the high delta of Lower Ammonosuc river, on 
the north side of Black river in Springfield, Vt. and in the high, broad 
plain of Hinsdale. The latter is the only one of these areas which can 
be compared in size with the extensive plains of central and eastern New 
Hampshire. 
