210 PEOCEEDINGS OF THE GEOLOGICAL SOCIETY. 



forced to follow when passing along the great escarpment that nOw 

 faces the Hudson. 



Though the principal grooves run in the directions stated, many 

 minor striations, such as might be expected from floating ice, cross 

 them at various angles. 



From this point I made two excursions into the higher parts of the 

 range, in the hope of finding similar markings : but so dense is the 

 forest, that it took two hours to walk a mile ; and though in several 

 places the rocks were exposed, they were too much weather-worn 

 to afford all the usual indications. I^evertheless the rounded contours 

 of all the mountain-tops always impressed me with the idea of glacial 

 abrasion; and if, as I believe, they were contoured and striated 

 by floating ice, then the drift-sea of the Hudson Yalley was at least 

 3000 feet deep, — and probably more, if, as is likely, the higher 

 peaks were also submerged. Judging by the general uniformity 

 that seems to have prevailed over North America in changes of level, 

 it would probably be safe to infer that this submergence also 

 extended to the Laurentine and other mountain-chains in the eastern 

 part of North America. 



Allowing that the striations on the eastern flank of the great 

 range were made by floating ice, it still does not follow that in the 

 interior there should be no traces of glaciers in the narrow valleys 

 on the opposite watershed, — such glaciers, if they ever existed, being 

 like some of those in North "Wales, of later date than the emergence 

 of the country from the drift sea. I had an opportunity of testing^ 

 this. In the gorge close to the south shore of the httle lakes, the 

 striations stiU run W. 10° N, ; and below that point the valley, 

 descending westward from 5° to 10°, is covered with boulders of 

 Catskill sandstone (see fig. 3). About a mile and a half down, at 

 the Falls of Catskill, the valley suddenly deepens ; and about two 

 miles further it curves round to the S.E. and S. ; and finally the 

 stream escapes from the Catskill Range, and flows towards the Hud- 

 son. On either side the valley is bounded by high steep slopes and 



Fig. 4. — Section of the Valley helow the Falls of Catskill^ 

 showing houlder-drift covering its sides. 



S. N. 



1. Drift. 2. Red Sandstone and Conglomerate. 



abrupt cliffs ; and the height and form of the ground is such that, 

 under favourable circumstances, it seemed as well adapted for the 

 formation of a glacier as many of the valleys of North Wales, had 



