GEOLOGY AND PALEONTOLOGY OF THE SCHOHARIE VALLEY 207 



bonaceous beds. This sliding lias resulted in the production of 

 numerous sliding planes or " slickensides " which show by parallel 

 striations the direction of movement. The mass has thus assumed 

 the superficial aspect of coal, which has led to the exploitation 

 of these beds. The slickensided layers are succeeded by heavy 

 bedded, arenaceous strata, chiefly limestones, which belong to the 

 Hamilton beds. Fossils here are mostly rare, but the little 

 pteropod, IS t y 1 i o I i n a f i s s u r e 1 1 a and some small 

 brachiopods are not infrequently met with in the black shales. 



The upper beds of the Marcellus formation are seen along the 

 northern slope of Sunset hill above the road which crosses the 

 col connecting that hill with Darin's hill. The outcrops are 

 mainly found on the edge of the woods, though occasionally in 

 the fields. Dark, often rusty, fissile shales, containing S t y 1 i o - 

 lina f i s s u r e 1 1 a in abundance, are seen below the sandstones 

 of the Hamilton group. Not far below the top of the formation 

 are some thin limestone layers, which are almost wholly com- 

 posed of two minute brachiopod shells, Lior h y n c h u s 

 m y s i a and S t r o p h a i o s i a t r u n c a t a , the former pre- 

 dominating. With these occur rarely Liorhynchus 1 i m i - 

 tar is. These same beds are again seen in the slope of East 

 hill, southeast of Schoharie, where the surface for 50 to 60 feet 

 above the Onondaga is covered with blocks of this limestone, 

 which is also largely used in the construction of stone fences. 

 The shales with Styliolina continue to about 75 or 80 feet above 

 the road, and are capped by the Hamilton sandstones. Prosser 

 reports 15 feet of black argillaceous shales in the bank of Mill 

 creek on the north end of Vroman's Nose. These shales contain 

 C h o n e t e s mucronatus? [fig. 150] , Styliolina fis- 

 sure! la [fig. 1531 , O r t h o C e r a s s u b u 1 a turn ? , and 

 crinoid segments. The locality is over a mile above Borst's 

 dam where the base of the Marcellus stands at the level of the 

 river. Willi a dip of about L35 feet bo the mile, the base of the 

 Marcellus would be carried more than that depth below the river 

 level. Furthermore as the outcrop is from 75 to 80 feet above the 



