Named as a member of Coburn Formation. Derivation of name not given, but probably from Coleville. Is a calcirudite divided into three units based on fossil content. Lower 9-ft section contains interlayers of crinoidal bioskeletal calcirudite. Middle 25-ft section extends from 9 to 34 ft above base of formation and contains subequal percentages of SOWERBYELLA bioskeletal calcirudite. Upper 139.5-ft section is distinguished by interbeds of DALMANELLA bioskeletal calcirudite and DALMANELLA-crinoidal bioskeletal calcirudite. Overlies Milesburg Member; underlies Antes Shale. Age is Middle Ordovician.
Source: GNU records (USGS DDS-6; Reston GNULEX).
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