- Usage in publication:
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- Madera Canyon Granodiorite*
- Modifications:
-
- Named
- Geochronologic dating
- Dominant lithology:
-
- Granodiorite
- AAPG geologic province:
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- Basin-and-Range province
Summary:
Named. Lies in north-central part of Santa Rita Mountains. Type area in lower reaches of Madera Canyon, Santa Rita Mountains, Mount Wrightson quad, Pima and Santa Cruz Cos, AZ. Is granodiorite stock that contains a light-gray main phase, a dark-gray melanocratic phase, and a porphyritic phase. Intrudes Josephine Canyon Diorite and is cut by upper? Oligocene rhyolite dikes. Biotite from the unit has K-Ar age of 67.9 +/-2.1 Ma. Is assigned a Late Cretaceous age.
Source: GNU records (USGS DDS-6; Denver 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 ([ ]).