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Geologic Unit: Stony Mountain
Map showing publication footprint
  • Usage in publication:
    • Stony Mountain formation*
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Williston basin
Publication:

Ross, R.J., Jr., 1957, Ordovician fossils from wells in the Williston basin, eastern Montana, IN Contributions to general geology, 1955: U.S. Geological Survey Bulletin, 1021-M, p. M439-M510.


Summary:

Assigned to Bighorn group as upper of two formations in subsurface of Williston basin. Cores studied are from wells in Roosevelt, Dawson, Wibaux and Fallon Cos, MT. Divided into a lower shale member (equivalent to Stony Mountain shale member of Stony Mountain formation of earlier workers) and dolomitic member in upper part (includes Birse, Gunton and Penitentiary members of Stony Mountain and Stonewall formation of earlier workers). Overlies Red River formation (revised) of Bighorn; underlies Silurian dolomites. Cross section of wells; fossil description and distribution. Late Ordovician (Richmond) age.

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


For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.

Asterisk (*) indicates published by U.S. Geological Survey authors.

"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).

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