REPORT OF THE STATE PALEONTOLOGIST 1901 619 



several ravines on the east side of the upper Genesee valley 

 opposite Fillmore. 



These beds which cap the Portage sandstones and still retain 

 the characteristic species of the rocks below have been termed 

 by Clarke the Wiscoy beds. They are composed mainly of soft 

 shale, bluish and argillaceous, or olive and sandy, with occa- 

 sionally thin black layers, a few flags or thin sandstones and 

 calcareous concretions. 



They are terminated by a band of flags and thin sandstones 

 that appear in the north wall of the ravine above the falls at 

 Wiscoy, and in the sides and bottom of the river channel a mile 

 south of Fillmore where they form '' Long Beards riffs." 



These latter sandstones are about 150 feet above the Portage 

 sandstones and are the lowest " coarse sandstones with fossils 

 of the Chemung group " that have been found in the immediate 

 vicinity of the Genesee river. They are succeeded by nearly 

 800 feet of shales and flags and these are overlain by the heavy 

 Rushford sandstones, exposed in the hills west of Caneadea. 

 Chemung fossils are common through this mass of shales and 

 sandstones. 



The Portage sandstones in the Genesee river are therefore 

 separated from any lithologically similar formation for 450 feet 

 above and none of like character of sufficient thickness to cause 

 confusion in correlation, occurs below. 



Recapitulating, the subdivisions of the rocks of the Portage 

 group in this section, that by their individual characteristics, 

 their homogeneity and their thickness are so well defined that 

 they may with safety be used in correlation with other local 

 sections, are : the lower black band, 35 feet, the Cashaqua shale, 

 130 feet, the second black band, 52 feet, the Portage sandstones, 

 182 feet. 



Besides these, there occurs in the lower part of the Gardeau 

 beds, interstratified between beds of shale, a band of flags and 

 thin sandstones aggregating about 25 feet in thickness, that 

 becomes a more distinct feature in the stratigraphy toward the 

 east, and will be referred to again in this paper. 



