of the Northern Cat skill Mountains. 151 



Hill and just below where the road crosses the stream, about 

 a mile above the Stamford reservoir, built up an exceedingly 

 perfect morainic loop which now encloses a small swamp, 

 once a lake. A couple of miles west of this, along the upper 

 two miles of the valley of Lamb Brook are strong morainic 

 loops evidently built up at the end of an ice lobe which pushed 

 from the north through the gap in the escarpment at the head 

 of the valley. 



The exact correlation of these various moraines must wait 

 upon more detailed investigations, but it seems evident that 

 the great Schoharie lobe lay banked against the Central 

 Escarpment, sending tongues of ice through the gaps and over 

 the lower passes opposite which the moraines are now found. 



All the moraines thus far described : namely, those in 

 the lower course of Town Brook between Hobart and Stam- 

 ford ; above the Stamford reservoir ; and at the head of 

 Lamb Brook, are believed to be nearly contemporary, and to 

 mark approximately the margin of the Schoharie lobe at the time 

 of their formation. The north-south striae north of Hobart are 

 believed. to be somewhat older. 



Moraines in Schoharie Valley. — The morainic system in 

 Schoharie Yaliey is complex because here, between Gilboa 

 and Prattsville, was the meeting place of two opposing ice 

 currents, one from the north, moving up the valley ; the 

 other from the south and east, moving down-valley. Two 

 lines of evidence lead to the above conclusion : in the first 

 place, the shape of the morainic loops indicates ice movement 

 in the directions mentioned ; secondly, there are two types of 

 material composing the moraines. Those to the north, formed, 

 according to this hypothesis, by ice moving up the valley 

 from the north, are yellow or bluish and carry a large percent- 

 age of northern bowlders — gneisses, limestones, etc., foreign to 

 the region. The moraines formed by the ice moving down 

 the valley from the south, on the other hand, are composed 

 almost exclusively of local material — red and gray sandstones 

 and red shales. 



Between Gilboa and Prattsville seems to be the meeting 

 place of these two morainic systems. At Devasego Falls, one 

 and one-half miles below the latter village, is a strong morainic 

 loop convex down stream. The moraine, in fact, by turning 

 the stream out of its normal course, produced the falls. The 

 down-stream side of the morainic loop is plainly not an ice 

 contact feature and presents many of the characteristics of a 

 delta front. It is composed of irregularly stratified sand and 

 clay, while the up-stream side is till. Nearly the whole loop, 

 which must have been built under the waters of Grand Gorge 

 Lake (to be described later) is overlain by red lake clay from 



