Thomasville member of Kinzers Formation, informally named by Gohn (1976: Univ. of DE, Ph.D. thesis), is the lateral equivalent of the newly named York Member at the Delta Carbonate quarry in York Co., PA. The sequence described by Gohn at the Thomasville quarry is a unique development of megabreccia and is not typical of the middle member of the Kinzers. The rocks overlying the Emigsville Member at Thomasville were first described by Cloos (1974) and included a lower breccia (up to 300 ft), bottom black limestones (20 to 30 ft), an upper breccia (50-300 ft), top black limestones (20 to 40 ft), and upper dolomites and limestones (350+ ft). The characteristic lithology of the middle Kinzers is pure white limestone. The megaclastic accumulations of the Thomasville have been interpreted as basin slope debris flows.

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