CHAPTER II. 
FORMATIONS OF CAMBRIAN AGE. 
HARDYSTON QUARTZITE. 
Wherever the sedimentary Paleozoic strata lie normally against the 
pre-cambrian crystalline rocks without faulting, both in the Kitta- 
tinny valley and in the outlying areas, the beginning of the sedimentary 
series is a rock with exceedingly variable lithologic characteristics, but 
always highly siliceous. In some localities it is a quartzite, some- 
times it is a conglomerate, often an arkose, and in its upper layers it 
becomes more and more calcareous, with some shaley beds.. This 
formation is known in New Jersey as the Hardyston quartzite. It 
was first named the Hardystonville quartzite by Wolff and Brooks,* 
but an abbreviation of the name to Hardyston seems desirable. ‘The 
same formation extends into Pennsylvania, where it is known as the 
Chiques sandstone,} and similar beds extend southward along the 
Appalachians. 
In New Jersey the thickness of the formation is as variable as its 
physical characters. Wolff and Brooks { gave its thickness as ranging 
from “thirty feet to a foot or less,” but their observations were re- 
stricted to the region about Franklin Furnace. In other parts of its 
outcrop the conglomeritic phase of the formation is known to equal 
or even exceed 200 feet. 
The age of the formation has been well established as Cambrian. 
In the early reports of the survey, without fossil evidence, it was corre- 
lated with the Potsdam sandstone of New York,§ but later, Beecher || 
first found fossils in the formation at Hardystonyille, belonging to 
the Trilobite genus Olenellus, which established its age as lower Cam- 
brian. Ata later date Foerste{ discovered additional fossil localities, 
* Eighteenth Ann. Rep. U.S. Geol. Surv., pt. II., p. 442. 
+ Penn. Geol. Surv., Summary, Final Report, vol. L., p. 165. 
t Loe. cit. 
2 Geol. N. J., 1868, p. 71. 
| Ann. Rep. State Geol. N. J. for 1890, p. 49. 
¢q Am. Jour. Sci. (8), vol. XLVI, p. 438. 
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