- Usage in publication:
-
- Magee Granite
- Modifications:
-
- Geochronologic dating
- AAPG geologic province:
-
- Midcontinent region
Summary:
Whole rock Rb-Sr age determined to be 1260 +/-30 m.y. Study area is in St. Francois Mountains, southeast MO, Midcontinent region. Same age as Munger granite porphyry; Magee and Munger are youngest rocks dated in this study. Older dated rocks include Silvermine and Butler Hill granites (1400-1450 m.y.); Hogan Mountain and Royal Gorge rhyolites, rhyolite of Johnson Shut-ins, and Pilot Knob felsite (1420 +/-30 m.y.); and Stout's Creek rhyolite (1315 +/-35 m.y.).
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 ([ ]).