GEOLOGY OF THE ATTICA AND DEPEW QUADRANGLES 15 



HAMILTON BEDS 

 SKANEATELES SHALE 



The term " Skaneateles shale " was applied by Vanuxem to the 

 beds overlying the Marcellus (Cardiff) shale and exposed on both 

 sides of the north end of Skaneateles lake. It subsequently fell 

 into disuse, but when the State Survey found itself compelled to 

 adopt a more exact and refined classification of the strata than 

 that hitherto in use, the term Skaneateles shale was re-applied in 

 its original meaning and scope. It is the lowest division of the 

 Hamilton beds, and on these quadrangles has an estimated thick- 

 ness of 40 to 50 feet. 



The passage from the Cardiff shale is a gradual one, there being 

 but slight difference between the upper beds of that formation and 

 the lower Skaneateles shales. They become lighter colored and 

 more argillaceous in the upper part but the formation as a whole is 

 much darker on these quadrangles than in the type locality. 



The Skaneateles shale is delimited at the top by a calcareous 

 band known as the Centerfield limestones. Fossils are common in 

 the lower and more calcareous portion of the formation, but rare 

 in the upper beds at most localities. 



The following species have been reported as occurring in these 

 beds on the Buffalo quadrangle : 



Phacops rana Green 



Cryphaeus boothi Green 



Primitiopsis punctuliferus Hall 



Orthoceras sp. 



Tentaculites gracilistriatus Hall 



Styliolina fissurella Hall 



Euomphalus (Phanerotinus) laxus Hall 



Bellerophon leda Hall 



Pterochaenia fragilis (Hall} 



Nuculites triqueter Conrad 



Orthothetes arctostriatus Hall 



Chonetes mucronatus Hall 



C. setigerus (Hall) 



C. scitulus Hall 



C. lepidus Hall 



Productella spinulicosta Hall 



Strophalosia truncata (Hall) 



Spirifer mucronatus Conrad 



Ambocoelia umbonata (Conrad) 



Liorhynchus limitare (Vanuxem') 



Tropidoleptus carinatus (Conrad) 



Crinoid stems. 



