- Usage in publication:
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- Crack Canyon Formation
- Modifications:
-
- First used
- Dominant lithology:
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- Arkose
- Conglomerate
- Mudstone
- AAPG geologic province:
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- Sacramento basin
Summary:
[Named by Lawton (1956, PhD thesis) in Morgan-Wilbur area in Lake, Yolo, and Colusa Co., CA]. Includes (ascending): "Blue Ridge Member" and "Grizzly Creek Member". Consists of arkose, several conglomerate lenses, and mudstone. Is 3600 feet thick. Composite columnar section of northern Great Valley sequence shows unit overlies "Knoxville Formation" and underlies "Little Valley Formation" of Lawton (1956). Age given as Early Cretaceous (Valanginian).
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 ([ ]).