622 CHARLES EMERSON PEET 



which was loo feet deep over the plateau, if the adjacent plateaus 

 be correctly interpreted. These figures are in accord with those 

 showing the depth of water in which the ice succeeded in making a 

 subdued moraine in the basin of Lake Passaic. They do not show 

 the total depth of water in the water body, but the depth only in 

 which the ice was able to build the moraine, kames, etc., mentioned. 

 If the proportion of ice to debris carried were known, it would furnish 

 a means of estimating the thickness of the ice on these moraines and 

 kames. 



In the Hudson Valley no less than fifteen halting-places are thus 

 indicated, and of these at least six are marked by distinct morainic 

 phenomena. This does not take account of the area between Pough- 

 keepsie and Catskill, which was observed only in transit. 



SUCCESSIVE POSITIONS OF THE ICE-EDGE IN THE PASSAGES FROM 

 HUDSON TO CHAMPLAIN VALLEY. 



The successive positions of the ice as it retreated from the Hudson 

 Valley into the Lake Champlain region are not known. In the 

 western or Lake George passage, after having built the Glen Lake- 

 Hopkins Pond kame area (Fig. i8, Nos. 87-89), thus forming the 

 dam that blocks the valley and makes the basin in which southern 

 Lake George is situated, the ice is not known to have made notable 

 deposits until the northern end of Lake George is reached, where 

 the western passage opens out into the Lake Champlain Valley. In 

 the eastern passage the successive positions of the ice-edge are not 

 known. It seems probable, however, that the ice-front had a direc- 

 tion such that local lakes were formed in tributary valleys in which 

 clays similar to those of the Hudson and Champlain regions were 

 deposited, but at levels higher than those reached by the Hudson 

 water body. 



SUCCESSIVE POSITIONS OF ICE-EDGE IN CHAMPLAIN VALLEY. 



The successive positions of the ice in the Lake Champlain Valley 

 are not well known. Some of its positions are marked by the ter- 

 races: (i) at Baldwin and northward (Fig. 18, No. 105, A, p. 455); 

 (2) at Street Road (Fig. 18, No. 107) and northward; (3) by the 

 moraine northwest of Crown Point (Fig. 18, northwest of No. 108); 

 (4) by limited gravel areas along the mountain-side from Port Henry 



