624 



Report of the State Geologist. 



A 7 . From the crest of the upper part of High fall to a stratum ]0 F 5| Kr 

 at the top of the small fall below the Adirondack railroad bridge the rocks 

 have a thickness of ten feet and two inches. A somewhat conspicuous 

 stratum, near the crest of the upper part of High fall, may be followed 

 along the bank as far as the bottom of the small fall below the railroad 

 bridge. The rocks are thin-bedded, rather coarse-grained and fossiliferous. 

 Zones A 5 , A 6 and A 7 of the present paper, with a total thickness of 138 feet, 

 are approximately equivalent to zones D 12 , D 18 , 1) 14 , D 15 and D 16 , of White, with 

 a total thickness of 166 feet. The greater part of this difference is in 

 the thickness of the rocks forming the lower part of High fall, which 

 measure by the Locke level seventy-seven feet, while they were estimated as 

 107 feet in thickness by Mr. White. 



1. Orthis (Platysfrophia) biforata (Schl.), Bill. (a) 



2. Orthis (Dalmanella) testudinaria, Dal. (c) 



3. Hajmesquma alternata (Con.), H. and C. (r) 



4. Crinoid segments. 



A % . This zone extends from the stratum noted at the top of the 57 F = e ^ 4 

 falls, just below the Adirondack railroad bridge, to the base of the massive 

 crystalline limestone which forms the upper part of the cliffs above the 

 railroad bridge. At this bridge is an excellent locality for measuring its 

 thickness, the base being marked by the rather heavy stratum which may be 

 traced from the top of the small fall below the railroad bridge to the vicinity 

 of the railroad pier ; and its top by the base of the massive limestone out- 

 cropping near the top of the cliff under the railroad bridge. This zone, 

 capped by the massive limestone, forms the sides of the gorge from below 

 the railroad bridge to Prospect village. It corresponds with zones D 18 , D 19 , 

 LP, D 21 and D 22 , of White, which were given as approximately eighty-seven 

 feet in thickness. They are thin-bedded, compact limestones, part of the 

 strata somewhat crystalline, separated by shaly layers. This zone contains 

 numerous fossils, some layers having large numbers of Orthis (JDalmcmelld) 

 testudinaria. At Prospect, along the sides of the creek from a little distance 

 below the falls to the highway bridge, is a good place for collecting. The 

 surfaces of sonic of the highly inclined layers, by the side of the creek just 

 above the highway bridge, show a large number of fragments of Asa/phus 

 plaPyc&phahiS. At the upper end of the gorge the rocks are very much 

 tilted, exhibiting the greatest amount of folding seen in any part of the gorge. 

 The cliff on the eastern side of West Canada creek above the Adirondack 

 railroad bridge is well shown in Plate V. The massive crystalling 



