I20 JOHN LYON RICH 



These morainic accumulations are composed almost exclusively of 

 local material. In the course of a half-day spent in tramping over 

 them, during all of which time a constant lookout for foreign rock frag- 

 ments was maintained, I found only one stone, a small piece of gneiss, 

 of other than local origin. This strictly local nature of the morainic 

 debris, taken in connection with the fact that all the terminal loops 

 are convex down-stream and all have distinct lateral moraines lead- 

 ing down to them from the hillsides, shows conclusively that for an 

 explanation we must look to local valley glaciers, and not to the conti- 

 nental ice-sheet, or tongues from it, pushing up toward the mountain 

 from the north. 



The valley of Fly Brook, all the way from the lake to its junction, 

 with the Schoharie Creek, a distance of three miles, suggests strongly 

 the idea that it was once occupied for its entire length by a valley gla- 

 cier. One and one-half miles below the lake, and about 20 rods below 

 the schoolhouse, are exposures of rock by the roadside showing striae 

 running in a northeast and southwest direction parallel with the axis 

 of the valley. Patches of mograine along the valley sides, the U -shape 

 of the valley bottom, and a peculiar morainic deposit where Fly Brook 

 joins the Schoharie, all suggest a valley glacier. 



PROBABLE EXTENDED LOCAL GLACIATION 



There is some evidence that south of Gilboa the Schoharie valley 

 and its tributaries were for a long time occupied by ice moving north- 

 ward and outward from the higher Catskills. The reconnaissance 

 nature of my visit to this region did not permit me to gather evidence 

 enough to fully substantiate this hypothesis, but there are many facts 

 which strongly suggest it. The following show the nature of the evi- 

 dence: (i) The local nature and red color of the moraines are very 

 conspicuous. At Gilboa, in the Schoharie valley, is a deep morainic 

 accumulation of distinctly northern drift, containing numerous pebbles 

 and bowlders of limestone and crystallines, and having a decided yel- 

 lowish color entirely characteristic of the northern drift, and very differ- 

 ent from the red of the local rocks. Overlying this is a thick deposit 

 of lake clay of the same yellowish color. At Devasego Falls, three 

 miles farther south in the same valley, is a moraine of an entirely differ- 

 ent character. It is convex down-stream; it consists largely of local, 



