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Geologic Unit: Kotlo
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Map showing publication footprint
  • Usage in publication:
    • Kotlo series*
  • Modifications:
    • Named
  • AAPG geologic province:
    • Alaska East-Central region
Publication:

Brooks, A.H., 1900, A reconnaissance from Pyramid Harbor to Eagle City, Alaska, including a description of the copper deposits of the upper White and Tanana Rivers: U.S. Geological Survey Annual Report, 21, pt. 2, p. 331-391.


Summary:

Birch Creek, Fortymile, and Rampart series of Spurr and Nasina series and Tanana schists of Brooks, 1900 (USGS 20th Ann. Rpt.) are grouped together on map under name "Kotlo series". This series embraces all gold-bearing rocks of Upper Yukon. Age is uncertain. If Rampart series are pre-Silurian, then Birch Creek, Fortymile, Nasina series and Tanana schists are probably pre-Cambrian or early Paleozoic.

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


Map showing publication footprint
  • Usage in publication:
    • "Kotlo" series†
  • Modifications:
    • Abandoned
  • AAPG geologic province:
    • Alaska East-Central region
Publication:

Brooks, A.H., 1906, The geography and geology of Alaska; a summary of existing knowledge, with a section on climate by Cleveland Abbe, Jr., and a topographic map and description thereof by R.U. Goode: U.S. Geological Survey Professional Paper, 45, 327 p. [Available online from the USGS PubsWarehouse: http://pubs.er.usgs.gov/pubs/pp/pp45]


Summary:

Now that more detailed studies have been made of Birch Creek, Fortymile, and Rampart series, name "Kotlo" can be entirely eliminated from the stratigraphic nomenclature.

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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