Scallion subinterval (informal) of Bottineau interval (informal) in Madison Formation. Extended into North Dakota from adjacent parts of Manitoba where it was previously defined as a member of the Lodgepole Formation [M.S. Stanton, 1956, Strat. of Lodgepole Formation, Virden-Whitewater area, Manitoba: Jour. Alberta Soc. Petrol. Geol., v. 4, no. 7, p. 164-167]. Basal part includes Carrington shale facies to southeast, and the less extensive Routledge shale facies to northeast. Five additional unnamed facies recognized: lime mudstone; interbedded shale-limestone; sand-silt; crinoid packstone-grainstone; and wacke-packstone. Underlies Virden subinterval (informal) of Bottineau interval; overlies Bakken Formation or older rocks. Age is Mississippian. Boundaries and mechanical-log characteristics shown.
See also P.F. Bjorlie, 1979, The Carrington shale facies (Mississippian) and its relationship to the Scallion subinterval in central North Dakota: North Dakota Geol. Survey Rpt. Inv., no. 67, 46 p.

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