Named as a member of Pierre formation for an exposure in the valley wall of Virgin Creek and in the flats and hills above it 1 1/2 mi south of Promise, northeastern Dewey Co, SD in Williston basin. Readily divisible into two zones. Measured type section beginning in cutbank along Virgin Creek, 1.5 mi south of Promise and extending to 1.8 mi south of Promise, Dewey Co, SD. In type section, a) lower Virgin Creek is 88 ft thick [base not exposed], and consists of hard, light-gray shale; contains 11 thin bentonite beds in lower half ranging from 3 in to 5 ft apart; bed of light-gray calcareous concretions form a ledge in creek bottom; weathers with a sub-metallic sheen; b) upper Virgin Creek is 100 ft thick and consists of medium-gray shale; breaks down to somber, leaden-gray gumbo; sporadic small perforated concretions scattered through lower part; weathers to bands of light gray, lead gray, and brownish gray; beds of concretions 1 ft or more in diameter, 30 and 70 ft above the base. Scattered small fossiliferous concretions in lower part. Overlain by Mobridge member (new); underlain by the Verendrye beds (new) of Sully member (new). Thickness of member varies from about 55 ft in Charles Mix Co, SD on Sioux uplift, to possibly 224 ft on Virgin Creek, northeastern Dewey Co. Lists fossils. Gives representative sections, and shows outcrop along Missouri River Valley, SD in Williston basin and on Sioux uplift. Cretaceous in age.

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

Is a member of Pierre shale in the Missouri River Valley, central SD in Williston basin and Sioux uplift. Includes all beds between the Verendrye member below and the calcareous Mobridge member above. The contact with Verendrye member is marked by beds of bentonite. At type section in Dewey Co, SD, is between 135 and 225 ft thick (Searight, 1937) and consists of gray clay and shale, the upper part of which has a zone of limestone concretions containing the fauna of the Sage Creek formation. Was named for an exposure in the valley wall of Virgin Creek, 1 1/2 mi south of Promise in northeastern Dewey Co, SD. Is of Late Cretaceous age.

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

Member of the Pierre shale, west-central and central SD and north-central NE in Williston and Salina basins. Shows ammonite zonation and correlation with other stratigraphic units in the Western Interior region. Late Cretaceous in age.

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

Three yellowish-white bentonite beds and two intervening gray shale beds above stream level at elevation 1,825 ft in Government Draw, Stanley Co, SD in Williston basin named Government Draw Bentonite Beds of Virgin Creek Member of Pierre Shale. Bentonite beds B1 and B4 form the base and the top, respectively, of Government Draw. Assigned a Late Cretaceous age.

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