1004 



NEW YORK STATE MUSEUM 



,/3X 



of 5 feet and are succeeded by 18 feet of black shale and 30 feet 

 of dark and light shales in thin layers. 



Rliinestreet black shales. As the lighter shales decompose more 

 rapidly than the black, the latter predominate in the coloring 

 and, specially in old exposures, give to this division the appear- 

 ance of being a homogenous bed of black 

 shale. The division has therefore been 

 termed the Rhinestreet black shale from 

 an exposure in the town of Naples. 



It is continuous from Yates county to 

 Lake Erie, and, unlike all of the forma- 

 tions below it down to the Onondaga 

 limestone it increases in thickness 

 toward the west. 



It is 20 feet thick in the Naples sec- 

 tion, 58 feet in the Genesee river cliffs 

 and 185 feet in the Lake Erie section. 



Fossils are exceedingly rare in these 

 black layers except terrestrial plant re- 

 mains, which are found occasionally, 

 sand} shale ^jfj-ed together and forming small thin 

 layers of impure coal. Fish remains 

 have been found in this horizon at 

 Sparta, Livingston co., and other locali- 

 ties toward the east, and a few speci- 

 mens of Lingula and an abundance of 

 conodont teeth have been obtained 

 from it. 



This bed is exposed in the cliffs on the 

 east side of Smoky hollow and at the 

 falls in the outlet of Silver lake at Gib- 

 sonville, also at the cascade in Buck run and on Cashaqua creek 

 at Tuscarora. It is the base of "the great development of 

 green and black slaty and sandy shales with thin layers of sand- 

 stone " between the Cashaqua shales and the Portage sand- 

 stones to which Professor Hall gave the name of "Gardeaa 

 shale and flagstones." 



black shale 



bottom of 

 Upper falls 



shales and 

 flags 



top of 



Middle falls 



Fig. 4 Section from top of 

 Middle Portage falls to abut- 

 ments of bridge above the 

 Upper falls. Stations 10, 11 



top of Upper 

 falls 



soft 



sandstones 



flags and 

 shales 



sandstone 



flags and 

 shales 



dark shale 



