I30 SURFACE GEOLOGY. 



on the west side of the railroad. The wide alluvial area here forms a 

 water-shed ; and half a mile farther south-east we come to a considera- 

 ble stream, which is one of the principal sources of Cochecho river. The 

 modified drift continues about a half mile farther, consisting of very coarse 

 irregular kames on the west side of the stream, while on the east side is a 

 plain of fine gravel or sand about 30 feet in height. The next four miles 

 of this valley, extending nearly to Farmington, has a rapid descent, and 

 is nearly destitute of modified drift. 



North-west from West Alton frequent kame-like deposits are found 

 along the road for three fourths of a mile. These consist mainly of sand 

 and gravel intcrstratificd, with numerous boulders enclosed or on the 

 surface, and are disposed in nearly level-topped, irregular terraces, with 

 gently-sloping escarpments. Similar kame-like terraces occur in Gilford 

 at two and three miles farther to the north-west. These all lie upon hill- 

 sides of till or ledge, which border the lake, at a height of about 75 feet 

 above it. Alluvial sand only 5 to 10 feet above the lake has been depos- 

 ited by a small brook near the north-east corner of Gilford, and also by 

 a stream which enters the lake below the last mentioned terrace, coming 

 from the valley east of the Belknap range. 



Two miles farther west we come to a large alluvial area, which borders 

 Gunstock river and Meadow brook, extending nearly a mile in width from 

 the lake to Lily pond, thus forming the water-shed probably not more 

 than 75 feet in height between the lake and Long bay. This modified 

 drift is gravel, sand, or fine silt, with a quite regular surface which slopes 

 gently to the lake. A considerable tract of it is interval, being over- 

 flowed by the freshets of Gunstock river. A continuous area of modi- 

 fied drift appears to extend north from Lily pond to the lake at a point 

 about one mile cast of the Wicrs. We here find, south from the bridge 

 to Davis island, very well marked kames, which form north and south 

 ridges 50 feet above the lake. They consist of water-worn gravel, with 

 pebbles up to one foot in diameter, and enclose occasional boulders. A 

 terrace of similar materials borders the hills on their west sides. 



All the ordinary modified drift which we found in our exploration of 

 these lakes has now been mentioned. A more remarkable class of 

 deposits, which has not been met with in other parts of the state, remains 

 to be described. 



