- Usage in publication:
-
- Steamboat Formation
- Modifications:
-
- Named
- Dominant lithology:
-
- Volcanics
- Sand
- Conglomerate
- Agglomerate
- Breccia
- AAPG geologic province:
-
- Modoc Plateau province
- Great Basin province
Summary:
[Probably named for Steamboat Canyon, Warren Peak 7.5' quad, Modoc Co, CA]. Occurs in Warner Mountains, northeastern CA. Is a series of well-bedded volcanics, sands and conglomerates interbedded with chaotic agglomerates and mudflow breccia, locally containing carbonaceous beds and fossiliferous silt. Is about 5000 ft thick. Stratigraphic chart shows unit underlies Deep Creek Formation (new). In Steamboat Canyon area Steamboat Formation is intruded by numerous coarse-grained augite andesite sills. A dike north of Cedar Pass is considered to be late Eocene age (Daniel Axelrod, personal commun.). Age of units in study area given as Tertiary.
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 ([ ]).