550 NKAV YORK STATK MUSRUM 



great majority of the organic remains were obtained from the 

 huge pile of rock material taken from the cutting and dumped 

 a little farther down the creek. 



The list of organisms collected in tliis last section will 

 demonstrate that they belong to another and entirely different 

 fauna, which represents a zone that in Europe has been found 

 to succeed that of the quarry beds. It is, hence, safe to assume 

 that the beds in the cut are a part of a terrane which over- 

 lies those exposed in the lower continuous section. In the 

 latter there are exposed upward of 123 feet of rock. The beds 

 in the dam cut, which is 135 feet long, may have reached 60 

 feet in thickness. Hence, even if the beds in the covered 

 interval of 825 feet (which, taking account of the dip, would 

 represent an approximate maxiumm of 330 feet) were repeatedly 

 folded on themselves, they would easily reach 100 feet in thick- 

 ness, and the rocks of all three zones, from the west to the east 

 end of the section must have attained a total thickness of 200- 



to 300 feet. 



The investigations carried on by Prof. T. Nelson Dale in the 

 slate belt of Vermont and eastern New York in the region ta 

 the north of the Deep kill have shown the occurrence in a num- 

 ber of localities of " dark gray calcareous or very quartzose, 

 finely bedded shales or black shales with thin limestone bed* 

 immediately overlying the ferruginous quartzite " which is con- 

 sidered of Cambric age.i It is added that these "are easily 

 overlooked on account of their inconspicuous characteristic* 

 and their inconsiderable thickness.'' In the table facing p. 

 178, the latter is given as 35 + feet. Graptolites found in 

 these shales were referred to Dr Gurley and determined 

 as follows: Bryograptus, Dichograptus, Callograptus 

 8 a 1 1 e r i ? rf. D e n d r o g r a p t u s sp. and D i c t y o n e m a 

 flabelliforme, and it was concluded that "several of 

 these are regarded as probably of Calciferous age." The genera 

 identified indicate that either the beds observed in these locali- 

 ties may be identical with those of one of the De ep kill zones, 



•Slate belt of eastern New York and western Vermont. 1809. p.185. 



