UPPEE SERIES OF KEENE VALLEY GROUP 655 



Theoretically, it is conceivable that as the ice to the south lying across 

 the Schroon Lake sheet gradually melted, the waters south of the divide 

 were separated from the portion of the Keene Lake lying in the Ausable 

 Valley, and so the Boreas-Elk-Clear Pond section became a distinct glacial 

 lake, which in turn may have subdivided into the "Boreas Lake" and 

 "Glacial Elk Lake," while the drainage of the remaining Keene Lake 

 flowed into this Boreas Lake through the pass east of Moose Mountain. 



The outlet of both these lakes was thus probably south or southwesterly 

 around the projecting ice-lobe in the Boreas-Hudson Biver depression, 

 although the eventual outlet channels have not yet been determined. 



The terraces of the Keene Lake are rather poorly defined, but are suffi- 

 ciently preserved to make possible the calculation of the Pleistocene de- 

 formation. Bemains of terraces in the Ausable Lake region are on the 

 2,000-foot contour, while a small terrace to the east of the Lower Cascade 

 Lake has an altitude of 2,040 feet. As these terraces are separated by a 

 distance of 13 miles, the amount of warping since the Keene Lake stage 

 is approximately 3 feet to the mile. 



The Keene Lake is 1 regarded as the younger of these two lakes, lying 

 at the 2,000 to 2,040-foot level. The extensive fill in the South Meadows 

 country is not duplicated in the Keene Valley, and the length of time 

 required to fill the former basin was evidently far greater than that re- 

 quired to form the comparatively small terraces in the Keene Valley. 



Eastern and western sections — Newman Lake (altitude, 1,740 to 1,875 

 feet) . — The water level that apparently succeeded both of the lakes above 

 described has considerable range, namely, from 1,740 to 1,875 feet. 

 Here also the question arises whether or not this may not be an outwash 

 plain. Our present knowledge is insufficient to enable us to settle the 

 matter. The writer is again inclined to the view that this level has been 

 formed in a glacial lake whose surface was being continuously or inter- 

 mittently lowered by progressive melting of some body of ice that con- 

 trolled the outlet. These high-level waters, in all probability, did not 

 have rocky outlet channels, but flowed over ice; hence their indefinite 

 character. 



Extensive sanely plains of the Newman Lake are situated about Lake 

 Placid. In the neighborhood of John Brown's grave terraces exist at two 

 rather well defined levels, the lower one at 1,740 to 1,780 feet and the 

 higher one at 1,800 to 1,820 feet. Bemains of terraces are found in 

 Keene Valley, chiefly on East Hill (the slopes of Hurricane Mountain), 

 and in the Johns Brook Valley. Here the separation of the terraces 

 seems impossible. 



Around the railroad town of Newman, from Avhich the name of the 



