34 NEW YORK STATE MUSEUM 



During Pleistocene times, with a retreat of the general ice sheet 

 to the north, a thick body of drift was left lying across the broad 

 valley south of Corinth. The elevation of this drift at its lowest 

 point was higher than that of the divide which separated the sources 

 of the stream above referred to from that of another preglacial 

 stream which flowed easterly to the Hudson plain. 



Due to the drift barrier, Luzerne river was diverted into the 

 course of the channel of the preglacial tributary stream at Corinth 

 and the waters, flowing over the divide, followed the course of the 

 eastward flowing preglacial stream, thus initiating the original 

 Adirondack-Hudson. This condition continued during an inter- 

 glacial epoch. During this time the divide was reduced and the 

 channel of the river lowered to the level of the present rock floor 

 of the valley upon which undisturbed till rests, as where the terraces 

 above described occur. 



With the readvance of the ice sheet, marking the end of the inter- 

 glacial period, two general effects were produced in the Adirondack- 

 Hudson valley ; first, the walls of the valley were somewhat reduced 

 and smoothed by the moving ice and projecting ledges and angles 

 at the summits of cliff walls were broken and worn away ; second, 

 the valley was partly filled in with the materials of the ground 

 moraine. 



When, in the final withdrawal of the ice sheet, the ice front stood 

 at Corinth, a connection between Lake Corinth and the eastern lake 

 which occupied the region southeast of Palmer was permitted. It 

 is evident from the correspondence in elevation of the deposits made 

 in the two lakes that they stood at approximately the same level. 

 It will be assumed, however, that prior to their, union there was 

 some difference in the level of their waters. As soon as their junc- 

 tion took place the outlet of the lower lake became the outlet of the 

 consolidated body of waters. If the eastern lake were the lower 

 then the outlet stream of the common waters naturally followed the 

 course of the interglacial river, occupying the already formed, 

 though now partly till-filled, valley. If on the other hand Lake Cor- 

 inth were the lower, the drainage was southward, over the aggrada- 

 tion plain, and thence in the course of the present drainage axis. In 

 either case the conditions thus established continued until the epoch 

 of flooded waters. 



As bearing on the question of the occurrence of an interglacial 

 epoch in the southeastern Adirondack region, it may be here noted 



