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Map showing publication footprint
  • Usage in publication:
    • Redcliff member
  • Modifications:
    • Original reference
  • Dominant lithology:
    • Dolomite
    • Breccia
  • 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. Redcliff member (informal) of Leadville Limestone. Massive micrite and dolomicrite; includes a persistent, 2 to 8 feet thick, very fine grained, tan to gray, dense dolomite at base. Thickness 41 to 84 feet. Unconformably overlies Gilman Member and unconformably underlies Castle Butte member (informal); both of Leadville. Fossiliferous; stromatolites occur 10 to 30 feet above base. Age is considered Early Mississippian (Kinderhookian).
Named from exposures near Redcliff, CO. Recognized in Eagle, Lake, and Pitkin Cos., CO.
[GNC remark (ca. 1990, GNC index card files, USGS-Menlo Park, CA): Author states this is an informal name.]

Source: Modified from GNU records (USGS DDS-6; Denver GNULEX); GNC index card files (Menlo).


Map showing publication footprint
  • Usage in publication:
    • Red Cliff Member
  • Modifications:
    • Principal reference
    • Revised
  • 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:

Red Cliff Member of Leadville Dolomite. Revised to include top 15+ feet of dolomite previously assigned to the underlying Gilman Sandstone of Chaffee Group by Tweto and Lovering (1977, = their beds 6, 7, and 8). Consists of dolomite and chert. Thickness 95.8 feet. Separated from Gilman (restricted) by M-1 unconformity and from overlying Castle Butte Member of Leadville by M-2 unconformity. Top of Red Cliff marked by 2-foot-thick "Pink Breccia." 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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