- Usage in publication:
-
- Arch Point basalt*
- Modifications:
-
- Named
- Dominant lithology:
-
- Basalt
- Volcanics
- AAPG geologic province:
-
- Alaska Peninsula province
- Alaska Southwestern region
Summary:
[Named for Arch Point in southwest part of Port Moller 1:250,000 quad, southwest AK.] [no type designated] Consists of flows occurring at: Arch Point, a few miles north of head of Volcano Bay, and at head of Belkofski Bay. Contains distinctive hexagonal columnar jointing, the columns averaging 4-6" in diameter. Rock is dark with conspicuous glistening black hypersthene phenocrysts 2 to 4 mm long. Source of flows not exposed. [Unconformably] overlain by Dushkin basalt (new) and alluvium; [unconformably] underlain by Belkofski tuff (new). Age is considered Quaternary based on regional relations.
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 ([ ]).