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- Usage in publication:
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- Star Mountain Rhyolite
- Modifications:
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- Geochronologic dating
- AAPG geologic province:
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- Permian basin
Summary:
Pg. 13. Star Mountain Rhyolite. Rhyolite sample from Swayback Mountain quadrangle, Jeff Davis County, southwestern Texas, yielded a K-Ar age of 37.9 +/-0.8 Ma (alkali feldspar). Data from D.F. Parker and F.W. McDowell, 1979 (GSA Bull., v. 90, p. 1100-1110), and D.L. Gibbon, 1969 (Bulletin Volcanologique, v. 33, p. 438-474); age recalculated using decay constants of Steiger and Jager, 1977 (Earth Planet. Sci. Letters, v. 36, p. 359-362).
[Age considered Eocene; Eocene-Oligocene boundary 36.6 (38-34) Ma (from Geologic Names Committee, USGS, 1983 ed. geol. time scale, with additions from N.J. Snelling, 1985, The Geol. Soc. Mem., no. 10).]
Source: Publication.
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
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"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 ( ).
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