652 XDW YORK STATE MUS2UM 



Marvlaml, niitl thonco south alonj; Ai>i»alai'hia, the* Oriskaiiian 

 einerjroiu'c contiuiicd to close of Ouondajjja tiiiie;aiud, as we have 

 already described in considering the Cayngan emergence, af- 

 fected not only the Appalachian Mediterranean but the south- 

 eastern area of the Mississippian sea as well. In middle Vir- 

 ginia emergence began early in Oriskauy time, since no true or 

 Upper Oriskauy is known in southern Virginia or Tennessee. 

 To the north of Cumberland Md. the Oriskauy is unequally 

 developed, but in eastern New York it appears to be the higher 

 portion only that is present, ^^'ith Lower Oriskauy only in the 

 southern extremity, and Upper Oriskauy only in the northern 

 end, the movements evidently were directly opposite at the two 

 extremities of the Cumberland basin during Oriskanian time. 

 The land conditions that succeeded the Oriskauy in the Cumber- 

 land basin continued till about Marcellus or Middle Devonic 

 time, when the later Devonic deposits of the Skunnemunk inva- 

 sion were laid down. 

 Oriskanian Immediately succeeding the Oriskanv emergence of the Cum- 



invasion of * * 



the Mississip. bcrlaud basiu, there still remained in southern Xew York a 



plan sea 



depression through which the Atlantic fauna of the Oriskauy 

 invaded the Mississippian province. This invasion, coming in 

 from the southeast (the Esopus, which is only a phase of the 

 Oriskauy, is 7(10 feet thick, according to Ries,^ in Orange county, 

 N. Y.) si>read northward, over the Oriskauy, and, after crossing 

 the Helderbergian barrier at Rome, continued on westward by 

 way of Buffalo, where remnants of it are seen in the cement 

 quarries. 2 Finally, the last of this deposit is seen near Cayuga 

 Ont. 

 Onondaga Tlic Oriskauian invasion attained the last localitv about the 



invasion 



same time that the Onondaga invasion, coming in from the 

 southwest, arrived there, the result being that the Onondaga 

 and late Oriskauy faunas, originally very dissiuiilar in character, 

 became one, making together what is now known as the eastern 

 Onondaga fauna. 



' Kh's. N. Y. state pool. 1 nth an. rop't l.<i07. 1896. 1:402. 

 'Grabau. Geol. soc. Am. Bui. 11HK>. 11:355-02. 



