- Usage in publication:
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- Alder Hill basalt member (informal)
- Modifications:
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- Original reference
- Dominant lithology:
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- Basalt
- AAPG geologic province:
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- Sierra Nevada province
Summary:
Pg. 1453-1464. Alder Hill basalt member of Lousetown Formation. Consists of several flows of which olivine basalt is most widespread. Probably oldest flows in area. Potassium-argon age 2.3 Ma. Suggested that Truckee basin was downfaulted subsequent to extrusion of the olivine basalt. Faulting does not appear to have affected other nearby Lousetown flows (or groups of flows). At least 20 flows recognized in area. Nine are named and given informal member status in Lousetown formation. Age is early Pleistocene.
Named from occurrence on and in vicinity of Alder Hill, Truckee area, north of Lake Tahoe, northeastern CA.
Source: US geologic names lexicon (USGS Bull. 1350, p. 12).
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 ([ ]).