BIGSBY — PALAEOZOIC ROCKS OF NEW YORK. 351 



that is, of the Waterlime-group. In Herkimer and Oneida Counties 

 this conglomerate is closely associated with the Clinton beds which 

 immediately succeed it ; and, being there of coarse materials, they 

 would be readily confounded in one group with the conglomerate 

 (Hall, Pal. ii. 1). 



It is to be remembered that, extensive as the Oneida Conglomerate 

 is on the Atlantic side of North America, it has no place in the more 

 remote west. 



Place. — This rock is in very great mass in Oswego County ; and, 

 occupying all the interval between the mouths of Oswego and Salmon 

 Rivers, dips into Lake Ontario, never to be seen more to the west- 

 ward. From this large exposure in Oswego, it gradually thins off 

 in an E.S.E. direction, and disappears under other rocks a little east 

 of Utica. 



Passing to the S.E. and S. by the shores of the Hudson River, 

 and thence into New Jersey, Pennsylvania, and Virginia, this forma- 

 tion becomes very powerful, and forms distinct topographical features. 

 As examples of this, we may instance the Shawangunk Mountains in 

 the south part of New York, and the extension of the same range 

 in the Blue or Kittaling Mountain, which in its southerly pro- 

 longation crosses the River Delaware at the Delaware Water-gap, 

 and thence through Pennsylvania and the west part of Maryland 

 into Virginia. 



But the northern extension of this conglomerate from the frontiers 

 of New York is perhaps still greater than the southern ; for it can 

 be traced, with very few intervals, from the Valley of the Hudson 

 for 700 miles in a north-eastern direction to Gaspe, with a varying 

 but considerable breadth. At Gaspe, the Atlantic stops further 

 search. 



Position. — This varies with the locality. In central New York 

 there is perfect conformableness with the Silurian strata in general, 

 and we observe a slight inclination to the south and west. More 

 easterly, and nearer the seat of disturbance and metamorphism, the 

 group becomes highly inclined and displaced, like the surrounding 

 strata. Throughout the great Canadian continuation the dip is 

 high, and to the S.E., with occasional gentle deviations. On the 

 higher parts of the Shawangunk Mountains the Oneida Conglomerate 

 has been thrust up horizontally in thick-bedded cliffs, the flanking 

 rocks having an E.S.E. dip towards the Atlantic, and W.N. W. toward 

 the Mississipi. In a paper on Plutonic Action, in preparation, this 

 subject is further treated. 



Thickness. — In this respect we have great differences. In the 

 Shawangunk Mountains (which range from the New Jersey line, 

 near Carpenter's Point, to Ellenville and Warwarsing in Ulster Co.), 

 the maximum is under 500 feet ; in the S.E, part of New York it is 

 from b*0 to 150 feet (Mather, p. 356) ; Prof. Rogers makes it about 

 200 feet. 



Fossils. — Very few. Only perhaps a Brachiopod and a few Fu- 

 coids have been preserved. 



