434 



The Upper Devonian Deposits of Maryland 



Maeyland 

 Chemung sandstone member. 



Ferruginous shale and sandstone 

 beds. Palaeanatina angusta zone 

 at top. 

 Upper Chemung conglomerate. 



Middle sandstone and shale, 800 

 feet thick. 



Lower Chemung conglomerate, 

 containing the upper recurrent 

 Tropidoleptus carinatus fauna. 



Lower shale and sandstone beds, 

 600 feet thick. 

 Parkhead member. 



Parkhead sandstone member con- 

 taining the recurrent Tropido- 

 leptus carinatus fauna. Beds 

 more arenaceous eastward. 

 Woodmont shale member. 



Beds containing Ithaca fauna. 

 Liorhynchus globuliforme zone. 



Cladochonus-Reticular ia Isvis 



zone. 

 Beds containing Naples fauna. 



Alternating shale and flagstone. 



G-enesee black shale member. 



Absent eastward. Genesee fauna. 



New York ' 

 Chemung formation. 

 Absent. 



Fall creek conglomerate. Corre- 

 lation doubtful. 



Wellsburg member, sandstone and 

 shale 600 feet thick. 



Zone containing upper recurrent 

 Tropidoleptus carinatus fauna. 



Cayuta member, shale and sand- 

 stone 600 feet thick. 

 Portage formation. 



Enfield member. Containing the 

 recurrent Tropidoleptus carina- 

 tus fauna. Beds more arena- 

 ceous eastward. 

 Ithaca shale member. 



Liorhynchus globuliforme zone of 

 Ithaca fauna of eastern New 

 York. 



Ithaca fauna of central New York. 



Sherburne member. Containing 

 Naples fauna. Alternating 

 shales and flagstones. 

 Genesee black shale formation. 

 Absent eastward. Genesee fauna. 



CORRELATION -WITH PENNSYLVANIA 



The Upper Devonian of Pennsylvania has not been studied as fully as 

 that of New York, the criteria available for correlation being chiefly 

 lithological and, hence, attended v?ith much uncertainty. The essential 

 identity of the Upper Devonian deposits of New York and Maryland 

 lender.s it probable that the sediments of this age in Pennsylvania were 

 laid down under substantially the same conditions. Confident correla- 

 tion, however, must await fuller paleontological proof than is now 

 possessed. 



'Williams, H. S., Devonian Section at Ithaca, N. Y. Journal of Geology, 

 vol. xiv, 1906, p. 579. 



