The Lower Bridge Member is here named the lower member of the Williamsburg Formation of the Black Mingo Group in the Coastal Plain of SC. The here revised Black Mingo Group includes all the strata from the base of the Paleocene to the top of the Ypresian Stage of the Eocene and is divided into the Danian Rhems Formation, the Thanetian Williamsburg Formation, and unnamed Ypresian strata. [In the Clubhouse Crossroads corehole No. 1, Gohn and others (1978) assigned the entire Paleocene section to the Black Mingo Formation, and Gohn and others (1983) named the Ypresian strata the Fishburne Formation.] The Lower Bridge Member consists of fine-grained silicified mudstone, and fossiliferous, laminated, arenaceous shale. Unconformably overlies the Perkins Bluff Member of the Rhems; gradationally underlies the Chicora Member of the Williamsburg. Thickness at type section is 12 ft. Age is Paleocene (Thanetian, Sabinian).

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