r90 NEW YORK STATE MUSEUM 



Homowack, where it joins Sandburg creek, entering the valley 

 from the west and continuing down it to Ellenville. 



Two miles northeast of Ellenville, Rondout creek enters the 

 valley and follows it to the Hudson. 



The points, or rather the more important ones, noted in driving 

 down the valley from Summit ville to Rosendale, are these. 



At Summitville there is a considerable accumulation of drift in 

 the valley, and no evidence of any bed rock, None was seen in 

 the valley from Summitville to Ellenville, or indeed beyond this 

 point. The stream descends 90 feet from Ellenville to Port Jack- 

 son according to barometric readings, while from this latter point to 

 Rondout it descends 200 feet. From Ellenville to Port Benjamin 

 the valley is quite narrow, but it then begins to broaden out to the 

 northwest, and in the triangular area between Port Hixon, Mom- 

 baccus and Port Jackson, there is a low, undulating region under- 

 lain by considerable fine, sandy material and extensive beds of clay. 

 The first impression is that these might be associated with the 

 Hudson' valley estuary deposits, but their elevation, which is about 

 350 feet A. T. as near as 1 can estimate it from barometric readings, 

 would indicate a much greater postglacial submergence for this 

 region than hitherto supposed. One possible explanation, and it 

 seems to me a very plausible one, would be that a glacial lake existed 

 for a time in this region. One shore of this lake would be along 

 the northwest side uf Shawangunk mountain, another shore would 

 be along the southeast edge of the Catskills, while on the north the 

 water would have been held in by the ice, and the drift barrier at 

 Summitville would have checked it in that direction. Then again 

 the flowing off of the water to the southeast, down the valley from 

 Summitville to Port Jervis, might account for the abundant devel- 

 opment of a stream terrace below the former point, and its apparent 

 absence northeast of it, though it should be mentioned that the 

 valley from Summitville to Ellenville is narrower than southeast of 

 the former locality, and consequently any drift accumulations might 

 be more easily washed away. 



Whether the theory of a glacial lake is correct is a point which 

 could be proven only by more detailed field w^ork in the region 

 northwest and north of Port Hixon and Kerhonkson, but, as I have 

 said before, the facts seem to favor that view. 



