Bushkill Member of Martinsburg Formation named. Consists of thin-bedded dark- to dark-medium-gray claystone slate that weathers medium gray to very light gray to yellowish brown. Thickness about 4,000 ft. Estimate may be high because of repetition by unrecognized folds and thrust faults. Transitional contact with overlying Rameysburg Member (new name). Member is in conformable and gradational contact with underlying Jacksonburg Limestone. Occurs in northeastern PA and western NJ. Age is Middle and Upper Ordovician.

Source: GNU records (USGS DDS-6; Reston GNULEX).

Bushkill Member of Martinsburg Formation described in the Wallkill Valley, southeastern NY. Unit has greatest areal extent of the three members of Drake and Epstein (1969). Extends from at least as far south as Reading, PA, northeastward to and possibly beyond Newburgh, NY. In study area underlies informally named sandstone at Pinebush, a possible correlative of the Ramseyburg Member of PA and NJ.

Source: GNU records (USGS DDS-6; Reston GNULEX).

Paleontological collections from northern NJ, eastern PA, and southern NY confirm that Martinsburg can be divided into three members according to the nomenclature of Drake and Epstein (1967): Bushkill, Ramseyburg, and Pen Argyl Members. Bushkill and Pen Argyl are not age equivalents as has been suggested by other authors. Data show that Pen Argyl and Ramseyburg Members are definitely younger than Bushkill, but are insufficient to place upper limit on Pen Argyl.

Source: GNU records (USGS DDS-6; Reston GNULEX).