PORTAGE AND NUNDA QUADRANGLES 65 



South of the sandstone cliffs at Portageville the course of the 

 Genesee river winds through a broad valley in which the only 

 exposures of these soft beds are to be found in the various excava- 

 tions in the adjacent hillsides. 



The basal layers may be seen in the ravine y 2 mile south of 

 Bluestone; and at the falls of Wiscoy creek at Wiscoy the floor 

 and walls of the ravine display 135 feet of the middle and upper 

 beds. Near the top of the north walls above the falls the calcareous 

 sandstones occur that succeed this formation and are the lowest of 

 the " coarse sandstones with fossils of the Chemung group," re- 

 ferred to by Hall, in the Genesee river section. This band of 

 sandstones comes down to the river level 5 miles south of Wiscoy 

 and 1 mile south of Fillmore at Long Beards Riffs where it makes a 

 low cascade and is exposed on both sides of the river. It was 

 described and the designation " Long Beards Riffs sandstone " 

 applied to it by Luther in New York State Museum bulletin 69, 

 1903. The lower beds of the Wiscoy division are mostly coarse 

 blocky shales or soft sandstones with an occasional flagstone. In 

 the middle and upper parts the sedimentation is generally finer, and 

 there are several layers of black slaty shale one of which is 6 feet 

 thick. An 8 foot bed of nodular shales lies next below this black 

 bed and concretions from an inch to 3 feet in diameter occur 

 throughout the entire formation. 



Nearly all of the beds are calcareous to a greater or less degree 

 and on the whole greatly resemble the Cashaqua shale. This re- 

 semblance becomes even stronger toward the west, but is lost 

 to a certain extent toward the east owing to the increase of 

 arenaceous matter. 



The exposure at Wiscoy and in the ravines on the east side of 

 the valley 1 to 3 miles farther south afford the best opportunities 

 for examination of the Wiscoy beds. They are also exposed along 

 Stony creek 2 miles west of Warsaw and slightly along the upper 

 reaches of Relyea creek and Oatka creek, also east of the Genesee 

 valley for J4 mile north of Hunts along the Nunda road, and by 

 the roadside 1 mile southwest of Dalton. Small outcrops are com- 

 mon by the roadsides and in the ravines on the slopes of the hilly 

 region east of Nunda. 



In Steuben county where these beds are coarser they contain 

 many Chemung brachiopods and it is probable that the same species 

 occur in this horizon in the eastern part of the Nunda quadrangle, 



