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Map showing publication footprint
  • Usage in publication:
    • Castle Butte Member
  • Modifications:
    • Original reference
  • Dominant lithology:
    • Limestone
  • AAPG geologic province:
    • Eagle basin
Publication:

Nadeau, J.E., 1972, Mississippian stratigraphy of central Colorado, IN De Voto, R.H., ed., Paleozoic stratigraphy and structural evolution of Colorado: Colorado School of Mines Quarterly, v. 67, no. 4, p. 1-36.


Summary:

Pg. 80, 90-94. Castle Butte member (informal) of Leadville Limestone. Oolitic, pelletal, skeletal and composite packstone, grainstone and boundstone. Thickness 6 to 99 feet. Unconformably overlies Redcliff member (informal) of the Leadville. Underlies Belden Shale. Fossiliferous (endothyrid forams). Age is Late Mississippian (middle to late Osagean), based on fossils.
Type area: exposures in Castle Butte on Aspen Mountain, Pitkin Co., west-central CO. Named from Castle Butte. Recognized in Eagle, Lake, and Pitkin Cos., CO.
[GNC remark (ca. 1972, GNC index card files, Menlo Park, CA): Author states this is an informal name.]

Source: US geologic names lexicon (USGS Bull. 1520, p. 56); GNU records (USGS DDS-6; Denver GNULEX); GNC index card files (Menlo).


Map showing publication footprint
  • Usage in publication:
    • Castle Butte Member
  • Modifications:
    • Principal reference
    • Revised
  • Dominant lithology:
    • Dolomite
  • AAPG geologic province:
    • Eagle basin
Publication:

Beaty, D.W., Johansing, R.J., and Thompson, T.B., 1988, Stratigraphy of Mississippian Leadville Dolomite, Gilman to Leadville, Colorado; redefinition of the Castle Butte and Red Cliff Members, IN Thompson, T.B., and Beaty, D.W., eds., Geology and mineralization of the Gilman-Leadville area, Colorado: Society of Economic Geologists Guidebook, v. 2, p. 9-34.


Summary:

Castle Butte Member of Leadville Dolomite. Gray to tan, fine-, medium- to coarsely crystalline, massive dolomite and one thin-bedded gray shale. Thickness 15.5 feet. Separated from underlying Red Cliff Member of Leadville by M-2 unconformity, and from overlying Molas Formation by M-3 unconformity. Age is Mississippian.
Principal reference section (measured by Tweto and Lovering, 1977, USGS Prof. Paper 956, p. 23-32): at Rock Creek, 0.4 mi northwest of Gilman, in SW/4 sec. 12, T. 6 S., R. 81 W., Leadville mining district, Lake Co., west-central CO.
[GNU remark (ca. 1996, USGS DDS-6; Denver GNULEX): Considered a formal name.]

Source: Modified from 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 ( ).

Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).

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