Hardyston Quartzite

It was originally described by Wolff and Brooks in 1898,[1] where two outcrops in Hardyston Township, Sussex County, New Jersey, were described.

It is composed of a vitreous, light pink, steel gray or brown, locally arkosic, fine to coarse-grained, resistant quartzite.

Locally, where the unit is less than 10 ft thick, it is a fine- to medium-grained, gray, pyritic quartzite, grading into a dark-gray dolomitic sandstone.

The Hardyston unconformably overlies Precambrian crystalline basement rocks where it was deposited on an irregular surface and fills only the troughs or depressions.

[5] Miller and Myers extended the formation into Pennsylvania in 1939,[6] where it underlies the Tomstown Dolomite.