370 



New York State Museum 





DEVONIAN SYSTEM 





East Central 



Eastern 





UPPER 



Chautauquan 



UPPER 



Chautauquan 





Chemung beds 



Senecan 

 Portage beds 



(Ithaca fauna) 



Oneonta s.s. 



Ithaca sh. 



Sherburne s.s. 



Catskill beds 



Senecan 



Portage beds 

 (Ithaca fauna) 

 Oneonta s.s. 

 Ithaca beds 

 Sherburne s.s. 



Rensselaer grit 

 Skunnemunk cgl. 







HZ 



Bellvale sh. 



Tully horizon 



= 





MIDDLE 



Erian 



MIDDLE 



Erian 





Hamilton beds 

 Hamilton sh. 

 Skaneateles sh. 

 Marcellus sh. {incl. Cherry 



Hamilton beds 

 Hamilton shales 

 and flags 

 Valley l.s.) Marcellus sh. 



Cornwall sh. 



Dlsterian 



LTlsterian 





Onondaga l.s. 

 Schoharie grit 



Onondaga l.s. 

 Schoharie grit 





LOWER 



Oriskanian 



LOWER 



Oriskanian 





Esopus grit 

 Oriskany s.s. 



Esopus grit 

 Oriskany s.s. 



f Glenerie l.s. 



{ Port Jervis l.s. 



[ Connelly cgl. 



Helderbergian 



Helderbergian 



Alsen l.s. 



Becraft l.s. 



New Scotland l.s. 



Kalkberg l.s. 



Coeymans l.s. 



(Uppsr Manlius: Keyser) 



Port Ewen l.s. 

 Alsen l.s. 

 Becraft l.s. 

 New Scotland l.s. 

 Kalkberg l.s. 

 Coeymans l.s. 



(Upper Manlius 



: Keyser) 



The Devonian in New York State with some begins 

 with the Coeymans ; with others the Upper Manlius beds, 

 considered of Keyser age (Lower Devonian of Mary- 

 land and West Virginia) are regarded as basal Devonian. 

 This is discussed under the Manlius formation (p. 346). 

 Four stages or epochs of the Devonian are recognized: 

 the Helderbergian, named from the Helderberg plateau; 

 the Oriskanian, which includes the Oriskany beds; the 



