- Usage in publication:
-
- Placer River Silt*
- Modifications:
-
- Named
- Dominant lithology:
-
- Silt
- Clay
- Sand
- AAPG geologic province:
-
- Alaska Southern region
Summary:
Named for occurrence on Placer River. Type section designated as exposures in north bank of north fork of Portage Creek west of Seward Highway, Portage, AK. Consists of dark gray, olive-gray and brown micaceous silt of quartz and feldspar with intercalated silty clay or fine-grained sand. Thickness is 1.18 m with average of 1.07 m. Described as medium- and course-silt-size grains and thin-bedded to laminated. Overlies soil horizon rich in organic material. In 1973 Placer River Silt was still being deposited. Is Holocene age.
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 ([ ]).