REPORT OF THE DIRECTOR igi2 gj 



that this current which was a southerly to southwesterly one along 

 the eastern side of the Adirondack region changed to a more 

 westerly current along the southern side, and this is precisely what 

 would be expected in the case of a current sweeping partly around 

 a land mass occupying the central Adirondack area. 



Further, the very recent work of Ruedemann shows that the 

 shales of the lower Mohawk valley and Champlain valley which 

 have always been regarded as of Utica age are, in reality, of 

 Trenton (Canajoharie and Schenectady) age; that the Utica shale 

 is wholly absent from those regions ; and that there is no evidence 

 of their ever having been deposited there. Hence any argument for 

 the complete submergence of the Adirondacks during Utica time 

 receives a serious setback. 



In the Black River valley the Utica is followed without inter- 

 ruption by the Frankfort and Pulaski shales and sandstones. The 

 combined thickness (about nine hundred feet) there of the Utica, 

 Frankfort, and Pulaski clearly implies, even considering deposition 

 in a downwarping trough, that the sea spread well over the western 

 side of the southern Adirondack region. However, the very char- 

 acter of the Frankfort and Pulaski rocks, which contain so much 

 sandstone, implies comparative nearness to land undergoing pretty 

 rapid wear and more than likely this land mass, in part at least, lay 

 in the same general region as that of earlier time. In the vicinity 

 of Utica the Pulaski beds are missing, signifying dry land there 

 during that time, while on the southern and eastern sides the only 

 strata of Posttrenton age are the Indian Ladder beds of Albany 

 county which are thought to correlate with the Frankfort beds and 

 which signify local subsidence at that time for that region. The 

 outlier at Wells furnishes no data for Posttrenton time because of 

 the absence of any strata younger than Canajoharie age. 



South of Utica there is an important stratigraphic break between 

 the Oneida (Siluric) conglomerate and the underlying Frankfort 

 (Ordovicic) shales. This unconformity is very distinct so that prior 

 to the deposition of the Oneida the region around Utica was well 

 above sea level and undergoing erosion. The only possible source 

 of the pebbles in the Oneida formation would seem to have been an 

 area of Precambric rock, more than likely situated in that same 

 portion of the Adirondacks which never became submerged during 

 the Cambro-Ordovicic periods. That this uplift, which began in 

 the late Ordovicic, affected the region as far eastward as the Hudson 

 valley, and that the land remained above sea level for a long time 



