Named as uppermost member of Springer formation in the Ardmore basin in southern OK in the S. Oklahoma folded belt province. Named from Primrose Ridge in sec 7, T4S, R2E, Carter Co, OK, on which stand the buildings of the Primrose dairy farm. Type locality designated as on the nose of the Caddo anticline. Consists of 150-250 ft thick, very calcareous, hard semi-crystalline sandstone, interrupted by frequent shale partings. A ridge is formed by this sandstone. Locally contains two or three ft of fairly bluish limestone. Numerous flattish pebbles or small lenticular streaks of hard slate-colored shale occur in its sandstone and limestone beds. Lies from 250-500 ft above the Lake Ardmore sandstone [member] (new) of the Springer formation and about 1,000 ft below top of Springer. Overlies and underlies unnamed black shale of the Springer. Fossil list; geologic map; columnar section. Of Pennsylvanian age.

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

Revised in that Primrose formation overlies Union Valley sandstone in the frontal Ouachita Mountains of southern OK in the Ouachita tectonic belt province; both the Primrose and Union Valley are formations of Springer group of Morrow series of the Bendian period. Underlies Limestone Gap shale (new), also a formation of Springer group of Morrow series of the Bendian period. Exposed along the Choctaw fault zone. Foraminifera, Ostracoda, and conodonts are very prolific. Correlation chart. Carboniferous age.

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

Revised in that Primrose sandstone overlain by Gene Autry shale (new) in the southern Arbuckle Mountains of south-central OK in the S. Oklahoma folded belt province. Important fauna found in nearly continuous exposures across the strike of the Primrose; found here in two horizons. Numerous goniatite, pelecypods found. Overlies Lake Ardmore sandstone. Stratigraphic table. Measured sections. Is 490 ft thick at type section of Gene Autry shale in NW1/4 sec 34, T3S, R4E where the Primrose consists of fossiliferous shale and sandstone. Of Pennsylvanian (Morrow) age.

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