- Usage in publication:
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- Josephine Canyon Diorite*
- Modifications:
-
- Named
- Geochronologic dating
- Dominant lithology:
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- Diorite
- AAPG geologic province:
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- Basin-and-Range province
Summary:
Named. Extends from Madera Canyon south to flank of Patagonia Mountains and reappears in structural block of San Cayetano Mountains. Type area in upper reaches of Josephine Canyon, Santa Rita Mountains, Mount Wrightson quad, Santa Cruz Co, AZ. A dark-gray, moderately coarse grained, subophitic diorite that ranges to quartz diorite and granodiorite. Also contains fine-grained quartz monzonite. Intrudes rocks as young as the Salero Formation. Is unconformably overlain by Gringo Gulch Volcanics of Paleocene? age. Cut by Paleocene? dikes and by late? Oligocene pluton and dikes. Biotite from unit has K-Ar age of 67.1 Ma. Zr from unit has Pb-alpha ages of 63 and 61.3 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 ([ ]).