28 NEW YORK STATE MUSEUM 



levels are found to the westward of the area now under considera- 

 tion, nearly or quite up to Little Falls. It seems very probable that 

 the capacity of stagnant ice to maintain a barrier has been greatly 

 underrated. Such ice is often covered with debris. The streams 

 which would flow over it, proceeding from a recent glaciated region 

 would naturally be so overloaded that they would tend to aggregate 

 rather than to erode. No spillways or water-swept areas at the 

 proper altitude have been found on the hill flats westward from 

 Schenectady although some search has been made for them. The 

 problem demands further study but the evidence is conclusive that 

 lake waters in front of a waning ice tongue occupied a long section 

 of the Mohawk valley at about the altitudes indicated. 



There is some evidence that such conspicuous accumulations for 

 example, as the great sand flat " west of Fonda " is not altogether 

 and perhaps is not largely a delta of the Cayadutta creek, for on 

 the very borders of the Mohawk river on the south edge of the 

 lacustrine accumulation is found at least one locality cross-graveled, 

 dipping to the northward, whereas, as further north and toward 

 the head of the supposed delta, the deposits are silts and fine sands. 

 This points to the suggestion that the deposited part at least was 

 made wliile the immediate valley of the Mohawk was occupied by a 

 remnant glacier from which these gravels were derived. 



Deposits of Lake Albany age. The waters of Lake Albany ex- 

 tended up the Mohawk valley. The writer is not aware that this 

 fact has been sufliciently recognized, but by consulting the contour 

 maps of the valley it will be seen that the waters of Lake Albany 

 at an altitude of 340 or more feet would extend far up the present 

 course of the river. This also carries with it the interesting con- 

 clusion Ihat the Iroquois drainage which swept down the Mohawk 

 valley and is believed to have deposited as a delta the Schenectady 

 and Albany sands, must have been a drainage following the belt 

 of still water through a long stretch of the Mohawk valley. A 

 number of deposits of coarse gravels have been identified in the 

 area as probably belonging to the Lake Albany stage. It could not 

 have any reference to the present or recent work of the river and 

 they do not seem to belong to the earlier 440 to 460 foot stage 

 already described. Such deposits of coarse gravels occur down at 

 Yosts where they have been largely excavated by the New York 

 Central Railroad. They form a stone ridge east of Randall, south 

 of which ridge is an interesting old channel of the river waters. 

 They occur again in the hill about 40 feet in hight which extends 



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