138 SURFACE GEOLOGY. 



by Merry meeting rivet. The kames on the west side of Alton bay, a 

 mile and a half farther north, were formed at a later date, while the outlet 

 was in this direction. When the ice-sheet had retreated nearly to the 

 mouth of this bay, the outlet from its melting over the lake at the north 

 was along the low area a mile east of Fort point. As the melting of the 

 ice advanced towards the north-west, the kame-like terraces near West 

 Alton, and those in the north-east part of Gilford, were probably depos- 

 ited at the mouths of glacial rivers. Their height is that which the lake 

 held when its outlet was to the Cochecho valley. The series of kames in 

 Tuftonborough and Wolfeborough (p. 127) was probably formed at nearly 

 the same time by a glacial river from the north-west, after the ice had 

 disappeared from the south end of the lake and from the basin of Smith's 

 pond. The kames between Davis island and Lily pond indicate that the 

 drainage from the ice-sheet was by this avenue before it was melted at 

 the present outlet a mile farther west. A kame on the north side of Little 

 Squam lake marks the outflow from the melting ice-sheet over that basin. 

 The other deposits of modified drift about these lakes have been 

 brought down by short streams, and are scanty in amount because the 

 principal drainage of this area in the Champlain period was outward on 

 all sides. They appear to have been formed in the same way that deltas 

 are spread out nearly level at the mouths of tributary streams, often at an 

 elevation much above the jfloods in the main valley. The height of the 

 lakes during this deposition may therefore have been the same as now. 

 If they had ever stood for any long period at a greater height, the hill- 

 sides of till would be marked by a line like that of the present shore. 

 This is mostly composed of till, which presents a wall of boulders four or 

 five feet high, its liner portion having been washed away by the waves. 



Modified Drift ai.ong Magali.oway and Androscoggin Rivers. 



Mr. J. H. Huntington has kindly supplied information in regard to the 

 modified drift of the Magalloway and the upper portion of Androscoggin 

 river. He has also mapped the alluvial areas along the Upper Ammo- 

 noosuc river. The general geological map in the atlas shows the extent 

 of these deposits in New Hampshire, so far as definite boundaries can be 

 drawn.* 



*The Androscoggin river system is noticed in Vol. 1, on pp. 224-226, 301, 309-311, and 322. 



