U.S. Geological Survey Home AASG Logo USGS HOME CONTACT USGS SEARCH USGS
National Geologic Map Database
Map showing publication footprint
  • Usage in publication:
    • Wishbone formation*
  • Modifications:
    • Named
  • Dominant lithology:
    • Conglomerate
    • Sandstone
    • Claystone
  • AAPG geologic province:
    • Alaska Southern region
Publication:

Barnes, F.F., and Payne, T.G., 1956, The Wishbone Hill district, Matanuska coal field: U.S. Geological Survey Bulletin, 1016, 88 p., (incl. geologic maps, scale 1:6,000 and 1:12,000)


Summary:

Named for exposure on Wishbone Hill, Matanuska coal field, southern AK. Name first used on correlation chart (Payne, 1955). Rocks formerly lower conglomeratic beds mapped as part of Eska conglomerate by Martin and Katz (1912). Consists predominantly of conglomerate composed of pebbles, cobbles, and few boulders in sandy matrix. Includes lenticular beds of sandstone and lenses of silty claystone. Maximum thickness is 1850 ft. Overlies Chickaloon formation with gradational contact; unconformably underlies Tsadaka formation (new). Age considered to be probably Paleocene or possibly early Eocene.

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


Map showing publication footprint
  • Usage in publication:
    • Wishbone Formation*
  • Modifications:
    • Age modified
    • Biostratigraphic dating
  • AAPG geologic province:
    • Alaska Southern region
Publication:

Magoon, L.B., Adkison, W.L., and Egbert, R.M., 1976, Map showing geology, wildcat wells, Tertiary plant fossil localities, K/Ar age dates, and petroleum operations, Cook Inlet area, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map, I-1019, 1 sheet, scale 1:250,000


Summary:

Correlation chart shows age of Wishbone Formation to be Paleocene and early Eocene based on plant fossils.

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


Map showing publication footprint
  • Usage in publication:
    • Wishbone Formation*
  • Modifications:
    • Age modified
  • AAPG geologic province:
    • Alaska Southern region
Publication:

Winkler, G.R., 1992, Geologic map, cross sections, and summary geochronology of the Anchorage 1 degree x 3 degrees quadrangle, southern Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map, I-2283, 1 sheet, scale 1:250,000


Summary:

Unit age is Eocene based on regional relations (radiometric ages and fossils from overlying and underlying units).

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


Search archives

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: Thu 04 Apr 2024 04:19:15 PM MDT