LOWER SERIES OF KEENE VALLEY GROUP 661 



Soon after leaving the Copperas Falls the water ran along the edge of 

 the ice-lobe. Long boulder trains and boulder deltas extending from 

 Copperas Pond to Cross give evidence of heavy stream-work. 



In the same area a long glacial channel runs south from the intake of 

 the gulf channel. It passes through the fault pass of the "South Gulf," 

 as it is locally known (to the east of Black Mountain), through Coonrod 

 Pond, through Kelly Brook, through Hale Brook, and through the swamp 

 that encircles the western slopes of Mount Fay. Two small cataracts 

 occur where the 1,400-foot contour makes curious bends near the road 

 three miles northwest of Lewis. Various branch channels lead off from 

 this long channel to the east and represent successive channels opened up 

 by the retreating ice-lobe lying in the valley of the North Branch of the 

 Bouquet Eiver. This long channel was probably formed by the Avaters 

 of Saranac time, the successive lake levels being produced by the uncover- 

 ing of the side channels as indicated. 



The most interesting side channel so far investigated contains Orebed 

 Pond and the swamp a mile northwest of it. The contour map would 

 indicate that there were at least two cataracts here, but field-work failed 

 to reveal them ; evidently the topography is incorrectly drawn. 



The neighborhood of Copperas Pond contains several other cataracts. 

 Both Nesbit and Pound ponds are plunge basin lakes. Clear Pond is 

 probably a morainal lake, with perplexing eskers and a morainal ridge 

 clamming the waters. The reader's attention is drawn to the present 

 brook that flows through the Gulf. It will be noticed that the divide in 

 the fault is at one end instead of in the center, as is the case with the 

 majority of the major fault passes in the Adirondacks. Apparently the 

 flow has caused the high point of the pass to retreat to the west as stream- 

 cutting progressed. 



The pass to the east of Black Mountain and the valley in which Trout 

 Pond is now situated give evidence of the action of additional glacial 

 streams. A very interesting combination of geological phenomena is dis- 

 played in the fault valley to the east of Pokamoonshine Mountain. Here 

 is a typical block fault with the apparent downthrow to the east. The 

 mountain cliff is composed of Grenville schist and "rusty" gneiss, while 

 the valley rock is a granite-gneiss with a characteristic crushed zone be- 

 tween. On the very precipitous mountain face a series of trap dikes is 

 beautifully shown. They have been faulted and bent since their intru- 

 sion. One dike, estimated to be about 15 feet wide, has been broken up 

 into several pieces and offset from the original alignment. Along the 

 fault-line a glacial river forced its way, removing to a large extent the 

 crushed rock. What a wide range of geologic time is represented by 



