- Usage in publication:
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- Mitchell Creek Formation*
- Modifications:
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- Named
- AAPG geologic province:
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- Great Basin province
Summary:
Unit is named the Mitchell Creek Formation. Consists chiefly of metabasalt and meta-andesite flows and tuffs, now green schist; also minor amounts of calcarenite, locally crinoidal, grading to calcareous quartzite; also sideritic and phosphatic quartzite and black chert. Thickness of sedimentary rocks is more than 500 ft; thickness of volcanic rocks may be several thousand ft; base not exposed. Unconformably overlain by Tertiary volcanic rocks. Age is Early(?) Pennsylvanian based on fossils [conodonts].
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 ([ ]).