- Usage in publication:
-
- Gunners Cove formation*
- Modifications:
-
- Named
- Biostratigraphic dating
- Dominant lithology:
-
- Conglomerate
- Sandstone
- Tuff
- Basalt
- AAPG geologic province:
-
- Aleutian Islands province
- Alaska Southwestern region
Summary:
Named from Gunners Cove, small embayment on north side of Rat Island, Aleutian Islands, AK. Makes up about two-thirds of island. Unit includes tuffaceous conglomerate and sandstone, crystal-vitric basaltic tuff, and thin flows of basaltic lava. Exposed from sea level to altitude of 1050 ft. Inferred to be younger than Rat formation (new), but contact not exposed. Some cobbles of porphyritic andesite similar to rocks of Rat formation are in conglomerate of Gunners Cove formation. Age is Miocene or Oligocene based on fossils identified by F.S. MacNeil.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Gunners Cove Formation*
- Modifications:
-
- Age modified
- Biostratigraphic dating
- AAPG geologic province:
-
- Aleutian Islands province
- Alaska Southwestern region
Summary:
Age is late Eocene or Oligocene on basis of fossils. Table shows Foraminifera collected from southeast side of Gunners Cove, Rat Island (51 deg 48'40"N, 178 deg 19'E).
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 ([ ]).