rlOO NEW YORK STATE MUSEUM 



the relation is found to be persistent throughout the town. It 

 must be taken to explain the areal extent of the limestone along 

 a general n.w.-s.e. direction. The limestone is found occurring in 

 numerous bands, which the valleys follow. These courses are the 

 directions taken by several of the rivers, and where the streams 

 do not follow along the soft limestone beds, they cut across the 

 strike at a right angle and thus take the next most economical 

 course for them. The middle branch of the Hudson river in 

 Minerva represents the course taken by a branch stream, on 

 soft limestone, in effecting the capture of the upper waters of 

 the Hudson. The " fishhook " bend taken by that river at 

 Gooley is characteristic for stream capture. 



Extended sections of the gneiss are met in going up Beaver, 

 Moxham, or Dutton mountains. Frank, Split rock. Mink, Beaver 

 and Thumb ponds have their beds in the gneiss and show many 

 exposures along their shores. They are connected by swamp 

 lands, or are separated by almost imperceptible divides. The 

 gneiss extends westward into Hamilton county, where it is 

 associated with limestone, at the Chain lakes. First, Second, 

 Sixth and Seventh lakes are entirely in the gneiss, and the 

 same rock is found along the north shore of Fifth lake. 

 Third lake lies on the contact between the gneiss which ap- 

 pears along its southern edge, and the limestone. The latter, 

 of the usual coarsely crystalline graphitic variety, is found 

 standing in bold cliffs along the north shore. 



The gneiss is exposed in a single section of nearly 100 feet in 

 the hill halfway between Sherman pond and the pond which is 

 drained by Deer creek. Many alternating bands occur, coarse 

 and fine, with members so rich in mica as to go over toward the 

 schists. A band is found toward the top which is almost entirely 

 coccolite and quartz. The pyroxene is in light green granular 

 crystals. The extinction angle and interference colors are high. 

 The quartz is notable for its inclusions of garnet. These are 

 colorless and give six^sided or rhombic sections. They are 

 bounded by faces of the rhombic dodecahedron (101). 



