550 D. W. JOHNSON LOCAL GLACIATION IN WHITE MOUNTAINS 



continental ice in the region necessitated further caution to avoid mis- 

 taking features formed by tongues of the main ice-body for evidences of 

 local glaciation. I have placed unusual emphasis on these precautionary 

 measures because I want to use conclusions reached in the Catski 11 study 

 as arguments against the theory of an early date for cirque-cutting in the 

 White Mountains, and it is manifest that the value of the initial con- 

 clusions in this case depend on the care exercised by the observer in the 

 field. 



In the opinion of the writer some of the evidences of local glaciation 

 cited by Eich are open to doubt. This opinion is subject to the criticism 

 that it was based on a brief reconnaissance and not on any systematic 

 study such as Eich has given to the region. I believe, however, that 

 further investigation will show that some of the supposed morainic ac- 

 cumulations are in part at least of landslide origin. Occasionally what 

 look like landslip scars may be observed above the hummocky accumu- 

 lations on the valley floor. Some true glacial deposits ascribed to local 

 glaciation seem to me readily explicable as the product of local tongues 

 of continental ice moving up the valleys. In the lower valley of Fly 

 Brook are rock ledges showing striae which have been ascribed to local 

 glaciers. Some of these striae incline upward at an angle of 30 degrees 

 with the horizontal on the down-valley, sides of the ledges, while the up- 

 valley sides of the same ledges show no striae or only faint ones. Both 

 de Martonne and the writer are inclined to regard this as an indication 

 of ice moving up the valley, basing opinion on the expectable behavior 

 of ice when riding up over an obstruction in its channel and on analogy 

 with' similar phenomena observed in the Alps where the direction of ice 

 movement is not subject to doubt. We observed nothing which seemed 

 to indicate a movement of local ice for any appreciable distance down 

 valley. 



On the other hand, after eliminating all doubtful cases, there remains 

 abundant evidence to substantiate the principal contention of Eich, 

 namely, that local glaciers formerly existed in the Catskill Mountains. 

 Near the head of Little West Kill Valley are a number of ridges which 

 might conceivably have been produced by some form of landslide action. 

 But one of these ridges, after continuing down valley for some distance, 

 curves through an arc of 90 degrees and meets the valley wall abruptly 

 at a right angle. It has the form (plate 40, figure 2) and position of 

 a true moraine. In Fly Brook A^alley are two open ravines or amphi- 

 theaters, each containing typical crescentic terminal moraines convex 

 down valley. In one valley the moraine (plate 42, figure 1) is neatly 

 trenched by a postglacial stream notch ; in the other a beautiful moraine 



