- Usage in publication:
-
- Gakona formation*
- Modifications:
-
- Named
- Biostratigraphic dating
- Dominant lithology:
-
- Conglomerate
- Shale
- AAPG geologic province:
-
- Alaska Southern region
Summary:
Type locality designated as outcrop between Gakona Glacier and upper West Fork of Chistochina River, central Copper River region, southern AK. Consists of basal member of coarse conglomerate (500 ft thick) and upper part consisting of soft, fissile or massive, gray or buff-colored shales with interbedded gravel, sand and lignite beds. Total thickness is at least 2000 ft. Fossil plants indicate age is late Eocene. (Partial list of flora identified by F.H. Knowlton included in report).
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Gakona Formation*
- Modifications:
-
- Age modified
- AAPG geologic province:
-
- Alaska Southern region
Summary:
Age of Gakona Formation is Oligocene [based on diagnostic flora] (J.A. Wolfe, written commun., 1974)
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 ([ ]).