Named a member of Pierre Shale for Red Bird store, NE1/4 sec 27, T38N, R62W, Niobrara Co, WY, Powder River basin. Previously described in outcrops on north flank of Black Hills as "unnamed silty and sandy member"--200 ft of gray, silty to sandy shale that contains iron-stained calcareous septarian concretions (Cobban, 1952). Type section given in NW1/4 SW1/4 sec 13 and NE1/4 SE1/4 sec 14, T38N, R62W, Niobrara Co, WY where member is 725 ft thick and consists of soft, silty shale that weathers light to medium gray. Contains numerous limestone concretions that weather light gray, yellowish gray, grayish orange, dark yellowish orange, and light brown to moderate yellowish brown and orange brown. Concretions ordinarily 1-2 ft in diameter and 6-12 in thick. Rests conformably on very dark colored Mitten Black Shale Member of Pierre; conformably overlain by unnamed dark-gray shale member of Pierre. Crops out along flanks of Black Hills, WY, MT, and SD in Powder River and Williston basins with thickness of 725-200 ft. Correlated with Judith River Formation at Porcupine dome in central MT; Parkman Sandstone Member of Mesaverde Formation at Salt Creek anticline, Natrona Co, WY; Hygiene Sandstone Member of Pierre near Boulder, CO; and Crow Creek and underlying Gregory Members of Pierre at Wheeler Bridge, southeastern SD. Fossil mollusks common; lists index fossils. Deposited marginal to marine sandstones. Age [Late Cretaceous] not stated.

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

Member of Pierre Shale. Gives a reference locality [section] for Pierre near Red Bird, secs 14 and 23, T38N, R62W, Powder River basin, in which the thickness of Red Bird is given as 607 ft. Consists of soft, silty shale containing yellow-, orange-, and tan-weathering fossiliferous limestone concretions. Conformably overlies Mitten Black Shale Member; conformably overlain by lower unnamed shale member. Lists fossils and shows faunal zonation. Shows correlation with named and unnamed members of Pierre Shale in eastern CO, western KS, central SD, eastern ND, and southwestern MT. Late Cretaceous (late Campanian) in age.

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

Is a member in the middle part of the Pierre Shale at Red Bird, Niobrara Co, WY in the Powder River basin. Assigned a late Campanian, Late Cretaceous age. Overlies Mitten Black Shale Member of Pierre. Underlies unnamed marine member of Pierre. Correlates with most of Parkman Sandstone Member, basal member of Pierre Shale in Powder River basin, with part of unnamed middle member and most of Parkman Sandstone Member of Mesaverde Formation in southern Wind River basin, with lower part of Rock River Formation in Laramie basin, and with lower part of Allen Ridge Formation in Hanna basin. Correlation chart; aligned with lower BACULITES SCOTTI and BACULITES GREGORYENSIS, and upper BACULITES PERPLEXUS ammonite zones [zones listed in descending order].

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

Pierre Shale identified in subsurface of eastern Powder River basin in WY in Niobrara, Weston, eastern Campbell, and Crook Cos, and in MT in Powder River and eastern Big Horn Cos. Pierre divided (ascending) into Gammon Ferruginous, Mitten and Red Bird Silty Members, and an unnamed upper part. Pierre overlies Niobrara Formation and underlies Fox Hills Sandstone. To west, name Pierre replaced by (ascending) Steele Shale (and its Ardmore Bentonite-newly assigned--in lower part, Sussex and Shannon Sandstone Members which are separated by, overlain and underlain by unnamed parts of Steele), Mesaverde Formation (and its Parkman Sandstone Member, at base, unnamed middle part, Teapot Sandstone Member at top), and Lewis Shale (and its unnamed upper and lower parts separated by Teckla Sandstone Member). Sussex and Shannon Members of Steele continue eastward under basin, and they become (new assignment) Sussex and Shannon Sandstone Beds of Gammon Member. Ardmore also continues eastward where it becomes (new assignment) a bed at or near base of Mitten. Red Bird is equivalent to Parkman, basal member of Mesaverde to west. Of Late Cretaceous age. [This nomenclature shown on 22 cross sections in this OC series.]

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