24 NEW YORK STATE MUSEUM 



III; Port Henry, 114; and 131, in the Ausable river embayment 

 near Peru. As these are in decided embayments of the west wall 

 of the valley it is possible that the high features are due to glacial 

 waters, or lakes lateral to the ice lobation in the valley. However, 

 the strength of the bars and their regular spacing does not favor 

 the idea of ephemeral waters like the narrow pondings alongside 

 the ice. It appears probable that the profile does not show the total 

 height of the marine inlet waters in the Champlain lake district. 

 The profile certainly does give the uplifted plane of the sea-level 

 waters in the • Champlain valley at the time those waters passed 

 around into the St Lawrence valley. It therefore seems as if 

 there might have been some little rise of the land in the Champlain 

 region while the ice front lay about Covey hill, and that the superior 

 beaches indicate the amount of such lifting above the datum plane. 

 This has an important bearing on the relation of the land uplift 

 to the withdrawal of the ice cap. 



It seems quite certain that through the Hudson valley, or to 

 about Glens Falls, number 89 of the profile, the wave uplift did 

 not overtake the retreating ice front. By the time the ice cap 

 had waned so as to expose the Champlain valley the weight of the 

 ice mass had so diminished that perhaps the northward-progressing 

 wave of land rise did affect the border of the ice-covered territory. 

 This is also suggested by the Iroquois beaches in the St Lawrence 

 valley. 



The history of the postglacial phenomena is possibly more com- 

 plex than here outlined, and there may be unrecognized factors in 

 the problem. 



The lower bars along the international boundary are mapped 

 in plate 5. 



Woodworth's line A-B in his plate 28 (no. 82 of the Hst of 

 writings), is nearly coincident with this profile. 



Plate II. This diagram should be 'Used in conjunction with 

 the maps, plates 5-7, 9. 



The shore features are plotted on the profiles according to their 

 isobases. The vertical scale is 264 times the horizontal. 



The lines for the uplifted Iroquois shore are drawn as straight 

 lines from Covey outlet to beyond Adams, ignoring any slight 

 curvature. Southwestward from Adams the line is given slight 

 curvature so as to intersect the Iroquois beach at Ontario, Wayne 

 county. 



The upper of the two lines of Iroquois is regarded as the closing 

 or extinction plane of the lake. If this be true then the lower line 



