4<4 A. W. GRABAU PALEOZOIC DELTA DEPOSITS OF NORTH AMERICA 



red sedimentation. As in the ease of the lower series of deposits, fossils 

 are absent from these formations, except in special cases to be mentioned 

 hereafter, and. like the lower series, this, too, mnst be considered of conti- 

 nental origin, as will presently be shown. But whether or not we accept 

 the continental origin of these deposits, it is evident that a land-mass 

 large enough to supply several thousand feet of clastic strata must be of 

 sufficient extent to be an effective barrier between the Salina basin and 

 the Atlantic. Certainly no connection with the sea could exist in the 

 region fronted by these deposits, and if a connection did exist it must 

 have been either to the north or to the south. 



The extreme northeastern outcrop of the Shawangunk conglomerate is 

 a little north of Binnewater station, on the TTalkill Valley branch of the 

 West Shore Eailroad between Kingston and Eosendale. Here it is about 

 10 feet thick and for the most part still carries good-sized pebbles. The 

 High Falls shales which overlie it also overlap it northeastward and ex- 

 tend to within a few miles of Kingston. From south of Kingston to the 

 head of the Helderbergs at Altamont, successively higher strata of Upper 

 Siluric (post-Salina) age rest on the eroded Hudson beds. These strata 

 are marine and they mark a transgression of the sea in that direction. 

 It is evident that this region was land before the deposition of the Coble- 

 skill. Eondout, and Mauling beds, and that hence no connection with the 

 sea could exist in this direction. Xo one has considered a connection 

 with the Atlantic north of this across the Adirondack region, for the im- 

 possibility of maintaining such a hypothesis is apparent : we realize that 

 nowhere in this region are there any remnants of Siluric strata of any 

 age until we reach eastern Xew England. These, as is well known, be- 

 long to an Atlantic district, distinct from that in which the typical 

 Siluric strata of Xorth America accumulated. Moreover, it is pretty 

 certain that the material of which the water-lime and the Manlius lime- 

 stone of eastern Xew York were formed was derived from the erosion of 

 the Ordovicic limestones (Trenton and earlier) which then covered the 

 Adirondacks : and since there is further every reason for believing that the 

 Lorraine beds also covered the Adirondacks. at least to a large extent, it 

 is evident that these must have been removed by erosion prior to the 

 attack on the limestones. There is, then, sufficient evidence to warrant 

 the conclusion that an extensive region from Kingston northward and 

 eastward was above water and subject to erosion, and that hence no con- 

 nection with the Atlantic was possible in this direction. 



What has been said of northern Xew York applies equally well to 

 Canada. Xowhere in Canada north of the Salina basin are any ] 



