AMMONOOSUC GLACIER 285 



Hitchcock reported in New Hampshire and Vermont, this has been re- 

 garded as the most important, because it, unlike the others, appears to 

 have moved in a direction opposite to that of the Canadian ice-sheet, 

 namely, westward and northwestward; and its records should therefore 

 be more easily distinguished from those of the regional ice movement. 

 The evidence on which Hitchcock based his belief in this local. glacier 

 will now be reviewed and analyzed with brief .comments. 



"The eastern slope of the hill between Maplewood [northeast of Mount Agas- 

 siz] and Bethlehem Junction is thickly strewn with large boulders of material 

 similar to the nearest ledges. Their position is suggestive of transportation 

 down the Ammonoosuc from the east. As similar rocks occur as far as the 

 Twin Mountain House, it is not unlikely that the Ammonoosuc glacier brought 

 them there ; but further study is required to demonstrate the proposition." 19 



Just how the position of these boulders at Bethlehem Junction justifies 

 Hitchcock's preference for a distant easterly source rather than the source 

 which he says is close at hand is not stated. 



"Many large blocks of a coarser grained granite than ordinary lie upon the 

 slope of Mount Deception, just opposite the Fabyan House, and along the turn- 

 pike for a mile easterly. These have not traveled far, having been derived 

 from the south base of Mount Deception. One piece is 22 feet long, 14 feet 

 high, and 10 thick. Those 6 feet in length are common. The fragments are 

 too far removed from the mountain to have accumulated merely by gravity." 20 



The field here described lies just south of Mount Deception, directly 

 on the southeastward path of the ice-sheet. Although no ledges outcrop 

 through the drift, near the blocks, Hitchcock assigns the district to the 

 Mount Deception granite area on his bedrock geology map. Here, then, 

 as in the case of the blocks west of Bethlehem Junction, blocks admittedly 

 of native rock are used as evidence of transportation from a foreign source. 

 The deposit referred to is a knob and kettle moraine, a short distance 

 east of Fabyans, consisting chiefly of sand, but well sprinkled with large 

 blocks. Like the moraine at Bethlehem and Carroll, it appears to mark 

 the rapid deposition of drift in ponded waters along the irregular south- 

 ern margin of the ice-sheet as it retired from the Upper Ammonoosuc 

 Valley. 



"The recent clearings disclose a sharp conical moraine south of the Mount 

 Pleasant House, perhaps 20 feet high, and very different in character from the 

 neighboring mounds of esker and river gravel. The many large granite blocks, 

 where the railroad approaches near the Ammonoosuc River, above Mount 

 Pleasant and near the upper falls, are also like a local moraine." 21 



19 Op. cit, p. 241. 



20 Op. cit, pp. 241-242. 

 a Loc. cit. 



