578 GEOLOGY OF OLD HAMPSHIEE COUNTY, MA8S. 



THE PELHAM LAKE AND ESKEE. 



Opposite Amherst the frontal range of gneiss which bounds the valley 

 is partly broken down, and a narrow portal opens into a great, rounded 

 upland valle}^ or clough, about conterminous with the boundaries of the 

 town of Pelham. (See 1 p, 1 pS PL XXXV, C, and fig. 32.) North and 

 south the high level is continuous and is grooved by shallow valleys. The 

 two on the north admitted the glacial waters to the lake, the one on the 

 south gave them egress to the Belchertown Lake, as detailed a few para- 

 graphs back (p. 576). 



The rocky bottom of the basin is about 560 to 580 feet above sea, and 

 it is filled up with coarse till to a quite level surface at 640 to 650 feet, and 



<Z0OOF£eT. 



MOmzONTAL^CALf ITfRTtCAL SCALE 



Fia. 32 Pelliam Lake section. A generalized section from Swift River to Fort River at East Street, drawn tlirougU 



Pelham, showing the dilfereut outlets of the Pelham lakes. 



this heavy deposit covers the whole southern slope of the basin. From 

 any point high up on this slope, as on the road to the well-known mineral 

 locality, the asbestos mine, one sees massive accumulations of sand, much 

 of it very fine and all well sorted, which rise in a series of terraces of 

 great regularity, with broad, flat surfaces and flat scarps, to a height of 

 1,000 feet on the east side and 830 feet on the north and west sides of the 

 basin, and are almost wholly wanting on the south side. Westward, the 

 highest terraces end abruptly when they come to the entrance of the basin. 

 At a lower level, 500 feet above sea, they seem to stretch, in the portal 

 terrace, right across this entrance, like a great earthen dam — the narrow 

 notch which the brook has cut being scarcely visible — and they dip steeply 



