164 J. L. Rich — Physiography and Glacial Geology 



Lower Lake Levels in Schoharie Valley. — An examination 

 of the divide on the west side of Schoharie Valley shows that 

 the first possible lower outlet for the waters of the lake is the 

 narrow, 300-foot-deep gorge 1 1/2 miles directly south of Bray- 

 manville Schoharie sheet), with bottom elevation of about 

 1320 feet, whereas the first possible outlet on the east side of 

 the valley is the 1200 foot divide at the head of Catskill Creek. 

 This, however, according to Fairchild* shows no evidence of 

 having carried a glacial stream of any considerable size. The 

 other, as represented on the map, bears the earmarks of a gla- 

 cial channel of considerable importance. 



The writer has not examined this possible outlet, and does 

 not desire to discuss it further than to call attention to the 

 statement on a preceding page, made before this possible out- 

 let had been located, namely, that the thick drift mass near 

 Gilboa village presents a remarkably flat top at about 1300 

 feet, which gives the impression of having been wave-deter- 

 mined. It may be that future work will show a correlation 

 between these features. 



Drift-filled Gorges and Hanging Valleys. 



Several drift-filled gorges and hanging valleys found in differ- 

 ent parts of the area deserve a brief description. 



Just below the main road crossing Mine Kill half way be- 

 tween Gilboa and North Blenheim (Gilboa quadrangle) is an in- 

 teresting waterfall where the stream cascades over the wall of a 

 pre-existing drift-filled gorge. The old gorge runs under drift 

 just south of the falls and, so far as could be determined, does 

 not appear again farther up stream. Below the falls the stream 

 follows the old gorge to Schoharie Creek, having only partially 

 cleared it of drift. Whether this drift-filled gorge is interglacial 

 or dates back to preglacial times is a problem for the future 

 investigator. This gorge, cut in rock across the prominent 

 bench in Schoharie Valley already mentioned, proves that the 

 bench, in part at least, is rock — not entirely drift, as the condi- 

 tions just above Gilboa might lead one to suppose. 



Mill Creek enters the village of North Blenheim through a 

 gorge in the rock platform which here extends part way across 

 Schoharie Valley at an elevation of about 940 feet, a little over 

 100 feet above the river level. (See sketch, fig. 14.) This 

 gorge is entirely postglacial; the older one doubtless lying to 

 the south under drift. 



West Kill flows across the platform in a partially excavated 

 drift-choked gorge. In the down-stream section this is partly 

 filled with stratified sandy clay, sometimes locally crumpled, in 

 which are embedded large iceberg (?) bowlders. A little farther 



* Fairchild, H. L., New York State Museum Bull., 160, pp. 26-7, 1912. 



