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  • Usage in publication:
    • Little Flat Formation*
  • Modifications:
    • Named
  • Dominant lithology:
    • Limestone
    • Siltstone
    • Sandstone
  • AAPG geologic province:
    • Wasatch uplift
Publication:

Dutro, J.T., Jr., and Sando, W.J., 1963, New Mississippian formations and faunal zones in Chesterfield Range, Portneuf quadrangle, southeast Idaho: American Association of Petroleum Geologists Bulletin, v. 47, no. 11, p. 1963-1986. [Available online, with subscription, from AAPG archives: http://www.aapg.org/datasystems or http://search.datapages.com]


Summary:

Named as lower formation of Chesterfield Range Group (new) for Little Flat Canyon in Chesterfield Range. Type section measured on southwest-trending spur in NW1/4 sec 29, T7S, R40E, to base of a series of prominent cliffs approximately 100 ft below crest of Chesterfield Range, Bannock Co, ID on Wasatch uplift. Replaces use of Brazer Limestone in southeast ID. Is composed of three members that total 965 ft thick. Lower member (126 ft thick) is red, pinkish-weathering siltstone and fine-grained sandstone with two fine-grained cherty limestone beds. Middle member (551 ft thick) is red, fine-grained, calcareous quartz, sandstone and siltstone, and gray, quartzose limestone. Upper member (288+ ft thick) is sandy to fine- and medium-grained, gray limestone. Overlies Lodgepole Limestone; underlies Monroe Canyon Limestone (new) of Chesterfield Range Group (new). Has Meramec brachiopods. Assigned to Late Mississippian.

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


Map showing publication footprint
  • Usage in publication:
    • Little Flat Formation*
  • Modifications:
    • Age modified
  • AAPG geologic province:
    • Wasatch uplift

Map showing publication footprint
  • Usage in publication:
    • Little Flat Formation*
  • Modifications:
    • Revised
    • Overview
  • AAPG geologic province:
    • Snake River basin
Publication:

Sandberg, C.A., and Gutschick, R.C., 1984, Distribution, microfauna, and source-rock potential of Mississippian Delle Phosphatic Member of Woodman Formation and equivalents, Utah and adjacent states, IN Woodward, Jane, Meissner, F.F., and Clayton, J.L., eds., Hydrocarbon source rocks of the greater Rocky Mountain region: Rocky Mountain Association of Geologists Field Conference Guidebook, p. 135-178.


Summary:

Divided into (ascending order): Delle Phosphatic Member (new) of Osagean age, Tetro equivalent of Osagean and Meramecian age, sandstone member, and sandy limestone member of Meramecian age in Little Flat Canyon, Chesterfield Range, Bannock Co, ID in Snake River basin. Little Flat lies in the foreland basin. Delle was called phosphatic member in earlier reports. Little Flat overlies Woodhurst Member of Lodgepole Limestone and underlies Monroe Canyon Limestone. Delle-Woodhurst contact is placed at top of a hardground formed on the Woodhurst. Delle also assigned as basal member of Aspen Range, Deep Creek, and Woodman Formations and of Chainman Shale, Deseret Limestone and Brazer Dolomite at other localities. Correlation of Little Flat with other lithostratigraphic units in Great Basin province and on Wasatch uplift, UT, and in Snake River basin, ID, shown on correlation chart. Areal extent map of Little Flat and of Delle.

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


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