ANCIENT WATER LEVELS OF CHAM PLAIN— HUDSON VALLEYS 103 



The Croton point deposits like the North Haverstraw delta rise 

 to about 100 feet above the sea level where they join the rock wall 

 of the Hudson gorge. At Tellers point the gravels and san«fe fall 

 off in night to about 25 feet above the sea. Nowhere on this 

 southern margin do there appear signs of glacial delta lobes. On 

 the contrary there are marks of erosion, either that by the Croton 

 river or by the action of the waves of Tappan sen. 



The wide and deep cut across the point is clearly due to erosion 

 following the deposition of the uppermost sands and is an essen- 

 tial part of the history of the changes in water level and the run of 

 streams following the disappearance of the ice from the north side 

 of this morainal stage. The outline of the cut, concave toward the 

 northeast, describes the path which the present Croton river would 

 in all probability take, were the Hudson flowing north instead of 

 south as it now does. If the Croton cut this channel the process 

 of doing so must have been at the beginning, by coursing over the 

 deposit then more extensive to the southward and filling in the 

 area between Croton point and the land known as Croton bay, the 

 opening of which has given a more direct path southward into 

 the Tappan Sea. 



Against this view it must be said that the boulder deposits at 

 Tellers point indicating the presence of the ice along the northern 

 edge of the delta indicate also the possibility that streams poured 

 out on that side from the ice and during the decaying stage of the 

 ice front when a stream became free from its load, it may well 

 have cut this channel quite down to the present level and that 

 independently of the presence or action of the Croton river. The 

 presence of creases across the surfaces of sand plains and deltas 

 laid down along the ice margin is one of the striking features of 

 many districts where the deposits were built partly above perma- 

 nent water level. 



Clays at Crugers. In the vicinity of Crugers a few clay pits 

 have been opened in glacial brick clays closely resembling in all 

 respects those on the opposite side of the river at Haverstraw. 

 The clays have an eroded surface, rising to various levels up to 

 nearly 100 feet. The deposits wrap about outcrops and occur in 

 the hollows between the older rock topography of the side of the 

 valley. Like those at Haverstraw the clays appear to have been 

 deposited in the roughened and broken down rock terrace of the 



