EARLY DEVONIC HISTORY OF NEW YORK AND EASTERN NORTH AMERICA 



The geographic conditions then in New York at this early date 

 maybe briefly outlined as follows: The great interior Mississippian sea 

 which stretched a broad arm eastward into the Appalachian region during 

 both earlier and later times, forming the Appalachian gulf, was, in the 

 Helderbergian period, excluded from the present western, southern and 

 central reo-ions of New York, for it was a time of elevation of the continent 

 and most if not all those portions of this State were then land, but land to 

 be again depressed and overridden for ages by the seas. This ancient con- 

 tinental land extended far to the south along the 

 present Appalachian region and east of it lay a 

 sea way which we know to have been bounded 

 without or on the eastern side by a land barrier, 

 probably of continental dimensions. It has been 

 argued with reasonable security that from the 

 southern Appalachians of Maryland and Ten- 

 nessee northward this sea way was a relatively 

 narrow channel, widening out at places into 



The (^riskany sea in New York, showing the 



basins favorable for the propagation of exten- western transgression 



sive faunas and forming an open connection with the ocean waters at the 

 south and a free passage for migrant organisms. We must thus predicate 

 for New York at the opening of the Devonic time a land area which was 

 practically the entire State save its eastern and southeastern portions where 

 the tides flowed through the marine waters of the Helderberg channel, 

 hemmed in on the east by a land mass of whose extent toward the present 

 Atlantic we have still much to learn. There is now before us the problem 

 as to the opening of this channel beyond the present site of the Helderberg 

 mountains eastward, and its course till it reached the open waters of the 

 ocean at the northeast. We can not in this place give expression to our 

 interpretation of this problem or full credit to the eff"orts others have madek 

 toward its solution till we have marshaled the evidence of the faunas it is 

 here proposed to discuss. We ma)^ again remark, however, that after 

 Helderberg deposits had long continued in New York, the basin or chan- 



