444 CHARLES EMERSON FEET 



seems to be 140 feet. It may have reached somewhat higher. The 

 only means of determining this Hmit seems to be the maximum Hmit 

 of the delta structure. The presence of kames or moraine does not 

 fix an upper limit to the water, as indicated by the North Haverstraw 

 kame-like bodies, at low levels and by kames at Camelot and other 

 places to be mentioned hereafter. 



Low-level terraces on the Fishkill and Quassaic have the same 

 import as those at Croton. It is a question how much erosion has 

 taken place in the Hudson Valley itself. If the ice was on the valley 

 sides and the waters discharging into the valley which was free from 

 ice, it would be expected that the valley would be filled entirely across 

 up to the level required by the slope of the deposits from each side. 

 Since the clay would naturally take a very gentle slope if the valley 

 was free, it would be expected to fill to a height somewhat less than 

 the height of the clay on each side, but not very much less. Alto- 

 gether it seems probable that the erosion here has been more than 

 100 feet, while in regions immediately north it is very much less than 

 this. 



II. HIGH-LEVEL TERRACE NORTH OF FISHKILL. 



One and one-quarter miles north of Fishkill a sand-and-gravel- 

 capped clay terrace at 100 feet at its outer edge and 120 feet at its 

 inner edge extends northward for about one mile, with a width of 

 less than one-quarter of a mile up to three-quarters of a mile. The 

 overlying gravel and sand have a depth of 6-10 feet, and the layers dip 

 south. Near its north end gravel and sand occur at a higher level, 

 with a slightly undulatory topography, which may mark the ice- edge 

 on the land when the terrace was building in the Hudson water body. 

 (See Fig. 9 south of No. 44 and north of 42.) 



III. CARTHAGE LANDING-LOVV^POINT AND ROSETON. 



At the northwest margin of the above-mentioned 100-120-foot 

 terrace a lower terrace of gravel-capped clay occurs at 20-40 feet 

 A. T. The clay in this terrace varies in elevation from sea-level or 

 below to 40 feet above sea-level. The gravel above the clay is coarse 

 and contains some sink-like depressions. (Fig. 5, C.) It extends 

 from a point one and one-quarter miles south of Carthage Land- 



