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Geologic Units: Itkilyariak
Map showing publication footprint
  • Usage in publication:
    • Itkilyariak Formation
  • Modifications:
    • Named
  • Dominant lithology:
    • Sandstone
    • Redbeds
    • Conglomerate
    • Breccia
    • Limestone
    • Shale
  • AAPG geologic province:
    • Alaska Northern region
Publication:

Mull, C.G., and Mangus, M.D., 1972, Itkilyariak Formation, new Mississippian formation of Endicott Group, Arctic slope of Alaska: American Association of Petroleum Geologists Bulletin, v. 56, no. 8, p. 1364-1369. [Available online, with subscription, from AAPG archives: http://www.aapg.org/datasystems or http://search.datapages.com]


Summary:

Distinctive redbed unit is named for Itilyariak Creek which flows northward from Sunset Pass in eastern Sadlerochit Mountains (T3N R30E). Assigned to Endicott Group as uppermost of 6 formations. Type section designated as exposures near a small tributary to Itkilyariak Creek in SW/4 sec 6, T3N R31E, UPM, in core of eastern Sadlerochit Mountains, Mt. Michelson quad, AK. Composed of red and maroon sandstone, conglomerate, breccia, and limestone interbedded with maroon and greenish-gray shale and light-gray quartzitic sandstone. Thickness is 45 m in outcrop and over 150 m in wells. Unconformably overlies undated unnamed shale and sandstone at type locality, and in some areas overlies unconformably or gradationally Kayak-Kekiktuk Formations (undivided). Underlies Alapah Limestone (Lisburne Group) gradationally. Age is Late Mississippian based on biostratigraphic dating of early Late Mississippian fauna.

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


Map showing publication footprint
  • Usage in publication:
    • Itkilyariak Formation*
  • Modifications:
    • Adopted
  • AAPG geologic province:
    • Alaska Northern region
Publication:

Armstrong, A.K., and Bird, K.J., 1976, Carboniferous environments of deposition and facies, Arctic Alaska, IN Miller, T.P., ed., Recent and ancient sedimentary environments in Alaska: Alaska Geological Society Symposium Proceedings, Anchorage, AK, April, 1976, 16 p.


Summary:

Itkilyariak Formation adopted. Described as part of transgressive depositional suite of Carboniferous rocks of Arctic Alaska. Redbeds and evaporites in formation may represent a slowing in rate of transgression, perhaps reflecting local progradation and development of mudflats and/or change of climate from humid to arid. Laterally equivalent but generally younger than Kayak(?) Shale.

Source: GNU records (USGS DDS-6; Menlo 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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