- Usage in publication:
-
- Port Refugio Formation*
- Modifications:
-
- Named
- Biostratigraphic dating
- Dominant lithology:
-
- Graywacke
- Conglomerate
- Siltstone
- Shale
- Basalt
- AAPG geologic province:
-
- Alaska Southeastern region
Summary:
Named for exposures at type locality at Port Refugio on northeast side of Suemez Island and includes west shore of Ulloa Channel from Port Refugio to Adrian Cove, AK. Composed of interbedded graywacke, siltstone, shale, conglomerate, pillow basalt, breccia, and aquagene tuff. Thickness is uncertain due to tight folding, but is estimated at several thousand ft as suggested by lateral extent along Ulloa Channel. Conformably overlies or is intercalated with Wadleigh Limestone (new). Underlies Peratrovich Formation in Shelikof Islands area. Assigned Late Devonian age based on stratigraphic relations and biostratigraphic dating of brachiopods associated with branching vascular plants and SPIRIFER DISJUNCTUS.
Source: GNU records (USGS DDS-6; Menlo GNULEX).
- Usage in publication:
-
- Port Refugio Formation*
- Modifications:
-
- Biostratigraphic dating
- AAPG geologic province:
-
- Alaska Southeastern region
Summary:
Age is Late Devonian (middle to late Famennian) based on ages of brachiopods.
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 ([ ]).