U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database
Geologic Units: Cochrane
  • Usage in publication:
    • Cochrane limestone member
  • Modifications:
    • First used
  • Dominant lithology:
    • Limestone
  • AAPG geologic province:
    • Arkoma basin
    • South Oklahoma folded belt
Publication:

Maxwell, R.A., 1936, The stratigraphy and areal distribution of the "Hunton formation", Oklahoma: Northwestern University Summary of Doctoral Dissertations, v. 4, p. 131-136.


Summary:

Pg. 132, 133. White to grayish-white, but locally bluish- or greenish-gray, massive crystalline limestone containing glauconite. Average thickness 12 to 15 feet. Unconformably underlies Dillard limestone member (new); unconformably overlies Keel limestone member (new).

Source: US geologic names lexicon (USGS Bull. 1200, p. 863-864).


  • Usage in publication:
    • Cochrane limestone member
  • Modifications:
    • Principal reference
    • Revised
  • AAPG geologic province:
    • Arkoma basin
    • South Oklahoma folded belt
Publication:

Amsden, T.W., 1957, Introduction to stratigraphy, Part I, IN Stratigraphy and paleontology of the Hunton Group in the Arbuckle Mountain region: Oklahoma Geological Survey Circular, no. 44, 1-57 p., See also Oklahoma Geol. Survey Bull., no. 84, pt. 6, p. 7-311, 1959 [1960]


Summary:

Pg. 4 (fig. 2), 6 (fig. 3), 13 (fig. 5), 16-19. Cochrane limestone member of Chimneyhill limestone. Unconformably underlies Clarita member (name replaces Maxwell's preoccupied Dillard); unconformably overlies Keel member. Type locality stated.
Type locality: in SE/4 sec. 5, T. 2 N., R. 6 E. [Pontotoc Co., OK]. Well exposed along banks of small tributary entering Chimneyhill Creek.

Source: US geologic names lexicon (USGS Bull. 1200, p. 863-864).


  • Usage in publication:
    • Cochrane Formation
  • Modifications:
    • Revised
  • AAPG geologic province:
    • Arkoma basin
    • South Oklahoma folded belt
Publication:

Amsden, T.W., 1967, Chimneyhill Limestone sequence (Silurian), Hunton Group, Oklahoma, Revised, IN Geological notes: American Association of Petroleum Geologists Bulletin, v. 51, no. 6, p. 942-945. [Available online, with subscription, from AAPG archives: http://www.aapg.org/datasystems or http://search.datapages.com]


Summary:

Cochran Formation of Chimneyhill subgroup [informal] of Hunton Group. Described from the Arbuckle Mountains, south-central Oklahoma. Overlies Keel Formation and underlies Prices Falls Member (new) of Clarita Formation; all included in Chimneyhill. Age is Early Silurian (Llandoverian). Report includes stratigraphic chart.
["Subgroup" not recognized as a formal stratigraphic rank term (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). Considered informal and should not be capitalized.]

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 ([ ]).

Accessibility FOIA Privacy Policies and Notices

USA Gov U.S. Department of the Interior | U.S. Geological Survey
Supported by the National Cooperative Geologic Mapping Program
Page Contact Information: Personnel
Page Last Modified: Tue 25 Feb 2025 01:54:50 PM MST