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Geologic Units: Penrod
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Map showing publication footprint
  • Usage in publication:
    • Penrod Quartz Monzonite
  • Modifications:
    • Named
  • Dominant lithology:
    • Quartz monzonite
  • AAPG geologic province:
    • Peninsular Ranges province
Publication:

Brown, A.R., 1981, Structural history of the metamorphic, granitic and cataclastic rocks in the southeastern San Jacinto Mountains, IN Brown, A.R., and Ruff, R.W., eds., Geology of the San Jacinto Mountains: South Coast Geological Society Guidebook, October 10-11, 1981, no. 9, p. 100-138.


Summary:

Named and type locality designated for granitic stock on west side of Penrod Canyon, center, sec.33 T6S R4E, southeast San Jacinto Mountains, Idyllwild 15' quad, Riverside Co, CA. Name first used in thesis, Brown, 1968), and mapped in Brown (1980). Consists of light-gray to light grayish-tan (weathered) biotite-garnet quartz monzonite. Is approximately 4.5 mi long and 2 mi wide. Makes discordant intrusive contact with Desert Divide Group. Underlies Quaternary sediments including the Bautista Formation. Assigned Mesozoic (Cretaceous) age. [No basis given]

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 ([ ]).

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