117 



and may in fact have originated somewhere about the same 

 epoch, yet I much prefer the above designation in the present 

 stage of geological research, because the other name* involves 

 the notion of an identity of age, which, from the singular paucity 

 of organic remains in the American group, may probably never 

 be susceptible of demonstration. 



The whole middle secondary series, even where we find it, as 

 in Pennsylvania, presenting its most varied composition, is divi- 

 sible strictly into not more than three separate formations, the 

 lowermost and uppermost of which are conglomerates, while the 

 middle one, the main body of the series, is composed of the 

 ordinary red sandstone and red shale. In New Jersey, we find 

 the whole properly classified to embrace but the two upper of 

 these divisions, the red sandstone portion, and the uppermost 

 conglomerate, usually calcareous. 



Adopting, in conformity with our general plan, the ascending 

 order, we shall therefore describe in the three following sections : 

 I. The red argillaceous sandstone formation. 

 II. The variegated calcareous conglomerates. 



III. The trap rocks intruded among and overlying both of 

 these deposites. 



SECTION I. 

 Of the Red Argillaceous Sandstone. 



Geographical Range. — The southeastern margin of the red 

 sandstone formation coincides, from the northern State line to the 

 mouth of Newark bay, with the eastern boundary of the State. 

 Emerging from beneath the range of trap rocks called the Pali- 

 sadoes, on the west shore of ihe Hudson, it skirts the river and 

 its bay the whole distance, in fact, from Stony Point, in New York, 

 to the outlet of Newark bay, called the Kills, or Killvan Kiehl. 

 Between this spot and Perth Amboy, the edge of these rocks 

 crosses Staten Island. 



From Perth Amboy, we trace it along the north side of the 



* Employed by Professor Hitchcock, for the corresponding rocks in the valley of 

 the Connecticut riNxr. See Report on the Geology of Massachusetts. 



