Named the Red Run Member of the Waynesboro Formation in PA, MD, and WV for Red Run Creek, near MD-PA state line, in Franklin Co., PA. Consists of interbedded, light-olive-gray shale, light-gray, fine-grained sandstone, and medium- to dark-gray, sandy, dolomitic limestone. Thickness is 100 to 125 feet. Overlies the Dargan Member of the Tomstown Formation and underlies the Cavetown Member of the Waynesboro Formation. Lower contact placed below interbedded interval of calcareous shales with limestone and dolomite typical of the underlying Dargan Member of the Tomstown. Upper contact is gradational with overlying Cavetown Member and is placed in an interval of decreasing laminated dolomite and siliciclastics of the Red Run. The Red Run is of Early Cambrian age.

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