DETAILS OF SECTIONS. 19 



in that region, and is upon an average 173 feet above Deerfield river. This amount . 

 of sand and gravel (as I estimate it, 135,000 cubic yards) I supposed had been cut 

 away by Deerfield river, and sent forward into the Connecticut. But I can hardly 

 see why this ridge of terraces should in that case have been left. Yet some other 

 facts seem to indicate strongly that most of the whole basin has been thus exca- 

 vated; and upon the whole, I think this tongue of terraces has been formed by the 

 river after it had excavated the basin, and sent its contents down Connecticut river. 

 The tongue of terraces above described was undoubtedly at first a delta terrace, 

 though formed by the rapid stream as it issued from the mountains into the 

 estuary, which is now the Connecticut valley. At present, the ice-floods in that 

 stream, and at this very spot, exert an amazing power of erosion. In early times, 

 such floods must have crowded along great masses of crushed and rounded mate- 

 rials, and piled them up along the margin just as lateral moraines are produced 

 by glaciers. As the bed of the stream sunk, and also the waters of the estuary, 

 successive terraces would be formed, looking like so many moraines, although of 

 finer materials than the moraines of glaciers, and sorted too. 



14. This section extends across the Deerfield basin, though not exactly on a 

 right line. The eastern part starts at Deerfield river, just south of the village, 

 and the western part from the meadows, a little north of the village. Yet there is 

 no error in representing them as connected, since at their starting points they are 

 nearly on the same level, differing in height only as the banks of the river differ. 

 The terraces are very distinct till we reach the third, over which the railroad 

 passes, on the east side of the valley. Above the third, the top of the deposits is 

 only imperfectly level, and they may be regarded perhaps as beaches; for I am 

 confident that such beaches may be traced all along the flanks of the Connecticut 

 valley, at about the same height. But I have not measured them, save in a few 

 places, as they did not attract my attention when I measured the terraces. The 

 three lowest terraces on both sides of Deerfield river, were measured by levelling ; 

 the two highest, by the syphon and aneroid barometers. Yet the latter, on the west 

 side of the river, have not been measured at all. As I saw them from the east 

 side, they appeared to be at about the same height as those on the east side ; still I 

 know well how difficult it is to judge accurately in such cases by the eye alone, and 

 actual measurement might show a considerable discrepancy in the heights. Hence, 

 I have added an interrogation point to the heights on the west side of the river. 



15. This section, of no great importance, shows the terraces at the north end of 

 Deerfield meadows, to the top of Pettee's Plain, which lies southwest of the village 

 of Greenfield, and corresponds to the general level of the Connecticut valley. The 

 meadows, or lowest terrace, are here worn away, and the lowest terrace remaining 

 is mostly clay; the upper one sand. The river would encroach still further upon 

 this hill, had it not struck a ledge of red sandstone, which will at least retard its 

 lateral erosion. 



16. Pine Hill is an insulated eminence, apparently composed of two terraces, in 

 the northern part of Deerfield meadows. These terraces do not correspond in 

 height, as far as I can see, with any on the margin of the basin ; yet they must have 

 been once continuous, as I know of no instance where terraces have been formed 



