Keownville limestone member named at top of the Ripley formation in Union Co., northern MS, where Ripley is divided into (ascending) transitional clay, Coon Creek tongue, McNairy sand member, sand of upper part of Ripley, and Keownville limestone member. Unit is commonly less than 100 ft thick and consists of yellowish-brown sandy limestone beds that are no more than 5 ft thick and are interbedded with yellow to dark-blue-gray fossiliferous sand units. At type section, 47 ft of yellow-brown sandy sideritic fossiliferous limestone in beds 1 to 3 ft thick alternate with yellow to gray micaceous fossiliferous layers of sand and represents full thickness of member. These beds are unconformably overlain by 8.5 ft of fossiliferous sand and clay of Prairie Bluff chalk. Below limestone sequence is about 120 ft of fossiliferous sand and sandstone beds of upper part of Ripley. Age is Late Cretaceous.

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