1 6 NEW YORK STATE MUSEUM 



distance from the state line in New Jersey. At High Falls the 

 Cobleskill limestone is underlain by a cement bed and this rests 

 on a thin fossiliferous bed of shaly limestone which in a previous 

 report has been regarded equivalent to the Wilbur limestone. 

 Southwestward from High Falls neither the Cobleskill limestone 

 nor any immediately preceding fossiliferous beds have been re- 

 corded. In New Jersey however the presence of the Cobleskill, 

 which is the equivalent of the Niagara of Dr Barrett, has been 

 recognized for some time, and at the Nearpass quarry the Decker 

 Ferry beds which lie directly below the Cobleskill are highly 

 fossiliferous. Here however there is no cement bed present as* 

 there is at High Falls. Below the Decker Ferry beds in New 

 Jersey lie the Bossardville limestone and the Poxino Island 

 shale, but no outcrops of these are to be found in New York in 

 Orange county. The Cobleskill and the upper part of the 

 Decker Ferry formation are shown in the ledges east of Cudde- 

 backville. Northeastward from this section no other outcrops 

 of these formations were observed till reaching the village of 

 Kerhonkson, Ulster co., where the Cobleskill is seen just north 

 of the village. Thence the formation was readily traced to near 

 Accord where both the Cobleskill and the Decker Ferry are well 

 shown in the railroad cut and the bank of the canal. These ex- 

 posures of the Decker Ferry formation are the best that have 

 been observed in the State. At Accord no cement is found be- 

 low the Cobleskill as at High Falls a few miles to the north- 

 east. Thus it is evident that in the comparative short distance 

 between High Falls and Accord this cement bed becomes so cal- 

 careous as to be changed to a limestone, while the presence of 

 the typical Decker Ferry fossils just below the cement at High 

 Falls indicates that this cement bed is the stratigraphic equiva- 

 lent of a portion of the Decker Ferry formation as developed at 

 Accord and farther south. 



Shawangunk conglomerate. A second problem has presented 

 itself during the progress of these investigations, namely, the age 

 of the unfossiliferous formations lying below the cement and the 

 Decker Ferry formation. While the Cobleskill limestone was 

 still regarded as equivalent to the Niagaran the underlying forma- 

 tions could not be interpreted as later than Medina and Clinton. 

 As we now recognize the Cobleskill to be above the Salina, the 

 age of these unfossiliferous deposits was brought in question. 

 The quartzites and shales resting upon the Shawangunk grit 

 and which have generally been correlated with the Medina and 



