- Usage in publication:
-
- Goodwin Canyon Quartz Monzonite*
- Modifications:
-
- Named
- Dominant lithology:
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- Quartz monzonite
- AAPG geologic province:
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- Basin-and-Range province
Summary:
Named for exposures along upper parts of Middle and South Forks of Goodwin Canyon in T5S, R20E, Graham Co, AZ in Basin-and-Range province. No type locality designated. Underlies about 8 sq mi. Moderately resistant to erosion. Varies considerably in mineralogical composition and texture, ranging from equigranular granite, quartz monzonite, and diorite to porphyritic granite and granodiorite to ophitic diorite. Most common type is coarse-grained, pinkish-gray granite that has crystals of pink potassium feldspar up to a cm across and smaller grains of quartz and white plagioclase feldspar speckled with 1-2 mm grains of biotite. Detailed petrographic description. Intrudes rocks as young as the Pinkard Formation (Late Cretaceous). Is presumably about the same age as the Santa Teresa Granite. Assigned an early Tertiary age. Geologic map.
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 ([ ]).