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National Geologic Map Database

Geologic Unit: Nanushuk

Usage:

Nanushuk Formation (AK*)


Geologic age:

late Early to early Late Cretaceous (Albian to Cenomanian)*


Type section, locality, area and/or origin of name:

Type section: belt of rocks beginning 5 mi north of junction of Colville and Anaktuvuk Rivers, and extending south for 30 mi, Arctic foothills, northern AK (Schrader, 1902; Gryc and others, 1951).
Reference sections (Mull and others, 2003):
(1) transition from upper Torok Formation into overlying lower marine part of Nanushuk Formation exposed along eastern bank of Nanushuk River on south flank of Arc Mountain anticline, in NW/4 sec. 19, T. 9 S., R. 7 E.;
(2) marine to marginal-marine part of Nanushuk Formation exposed on west bank of Nanushuk River at east end of Rooftop Ridge, in SW/4 sec. 7, T. 7 S., R. 7 E.;
(3) nonmarine part of Nanushuk Formation exposed in the axis of Arc Mountain syncline east of the Nanushuk River, in secs. 19 and 30, T. 9 S., R. 7 E.


AAPG geologic province:

Alaska Northern region*


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 does not conform with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005). This may be explained within brackets ([ ]).