MODIFIED DRIFT ALONG CONTOOCOOK RIVER. 



Ill 



Other notable deposits of sand and gravel, to be hereafter described, 

 occur at nearly the same level on both sides of this valley through Hills- 

 borough county. They arc usually two or three miles distant from the 

 Contoocook river, but in most cases border some tributary stream. 



At Hillsborough Bridge the river is enclosed on both sides for a short 

 distance by slopes of till. Below this place the alluvium forms low plains 

 between the railroad and the river. The fall of the Contoocook at Hills- 

 borough Bridge is 27 feet, its height at the head of this fall being 

 591 feet above the sea. At the head of Long fall, near the line between 

 Hillsborough and Henniker, it is 546 feet above the sea, and in the next 

 two miles it descends 113 feet through a narrow valley destitute of modi- 

 fied drift. 



In Henniker a small terrace 15 feet above the river is crossed by the 

 railroad near the foot of Long fall. A wider terrace, 30 feet above the 

 river, extends nearly a mile from the west village to the railroad bridge. 

 These are both on the north-west side, and are the only deposits of mod- 

 ified drift west of the principal village. At the east side of this village 

 an interesting assemblage of kames is found, consisting of water-worn 

 gravel, with the largest pebbles one to two feet in diameter, in three or 

 four north and south ridges, 20 to 50 feet in height, nearly parallel with 

 each other. They cover an area two thirds of a mile long and half as 

 wide, and rise to a height of 100 to 125 feet above the river^ which below 

 the village is 390 feet above the sea. It will be seen that these ridges lie 

 at right angles with the course of the valley, extending nearly across it, 

 and causing the river to flow around them in a southward bend. East 

 from the kames the river flows through intervals or low plains, 15 to 40 

 feet in height, which extend, with an average width of two thirds of a 

 mile, through the township. 



^ Two and a half miles east from Henniker village we find on the north 

 side of the river, south-west from Whittaker pond, another group of 

 kames lying in north and south ridges across the valley like the preced- 

 ing, and reaching a height of 100 to 150 feet above the river. The mate- 

 rial of these ridges is in part the usual water-worn gravel, but in some 

 portions it contains principally angular fragments of rock one to three 

 feet in dimensions. Whittaker pond is bordered on the south by a nearly 

 level deposit of coarse rounded gravel, about 75 feet above the river. 



