THE GHEEI^ lIlVEIt GLACIER. 



631 



that the bottDiii of the basin and these hiy-la deltas were formed at the same 

 time, which must have been near the end of tlie time of the high water 

 stand, when the ice had finally melted after having prevented the filling of 

 the valley. The dissected delta of the Green River itself where it leaves its 

 rocky gorge and enters the basin is shown in fig. 3G. 



But one traces with great clearness the broad watercourse, with its 

 abundant sands, from Bernardston across the north of Greenfield to where 

 the extended sand flats end suddenly and sink Ijy a great, irregular scarp 

 into this basin, and a little farther south the similar watercourse from 

 Factory Village, near Tin-ners Falls, passes across the middle of Greenfield, 

 and stands in the same relation to the southern part of this deep elongate 

 depression. It mxist thus have been filled had it stood empty in the way 





FlO.36. — Section of the Green Kiver delta at the north endof the Green River basin, where (he etroam comes out of its rocky 

 canyon, showing that the delta was sent hut little into the lake, and its front not eroded. 



of these two abundant streams, and I can therefore only su})pose that 

 here, in the northwest corner of the valley of the Connecticut, and in 

 this long depression between the mica-schist mass of Charlemont and the 

 red sandstone, a lobe of the ice, sent down the Green River Valley from 

 the high ground in Leyden across the whole length of Greenfield, lingered 

 till after the floods had ceased to come through the two passes mentioned 

 above, and after Fall River had ceased to flow west into the Greenfield Lake. 

 I do not think that the ice stood high above the level of the flood waters 

 in the flood time ; but, like tlie great bodies of ice described by Dall in 

 Alaska, it was submerged beneath the sands as a great continuous body 

 filling the valley and, on melting, allowing its load of sands to di'op about 

 50 feet to their present position. 



