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Quitman Mountains caldera volcanic rocks and volcanic rocks of sneed (Cox) Mountain and west of Victorio Peak

Quitman Mountains caldera volcanic rocks and volcanic rocks of sneed (Cox) Mountain and west of Victoria Peak
State Texas
Name Quitman Mountains caldera volcanic rocks and volcanic rocks of sneed (Cox) Mountain and west of Victorio Peak
Geologic age Phanerozoic | Cenozoic | Tertiary | Oligocene
Comments interbedded flows and pyroclastic rocks of the Square Peak Volcanics and Sneed (Cox) Mountain and west of Victorio Peak--small basalt flow remnants. Square Peak Volcanics comprises more than 1,000 m of crudely layered ash-flow tuffs and lavas that occur in the central Quitman Mountains caldera and were erupted during 3 main caldera-forming stages. Lithologies range from high-K calc-alkaline, metaluminous to peraluminous trachytes (45 percent by volume), quartz trachytes (25 percent by vol.), and rhyolites (30 pecent by vol.) according to Setter and Adams (1986).
Primary rock type trachyte
Secondary rock type rhyolite
Other rock types felsic volcanic rock; basalt
Lithologic constituents
Major
Igneous > Volcanic > Felsic-volcanic > Trachyte (Pyroclastic, ash-flow)
Igneous > Volcanic > Felsic-volcanic > Quartz-trachyte (Pyroclastic, ash-flow)
Minor
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, ash-flow)
Incidental
Igneous > Volcanic > Felsic-volcanic > Quartz-trachyte (Flow)
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Flow)
Igneous > Volcanic > Mafic-volcanic > Basalt (Flow)
Map references
Bureau of Economic Geology, 1992, Geologic Map of Texas: University of Texas at Austin, Virgil E. Barnes, project supervisor, Hartmann, B.M. and Scranton, D.F., cartography, scale 1:500,000
Unit references
Bureau of Economic Geology, 1968, Van Horn-El Paso Sheet, Geologic Atlas of Texas: Bureau of Economic Geology, The University of Texas at Austin, scale 1:250,000.
Setter, J.R.D., and Adams, J.A.S., 1986, Petrology and geochemistry of the Quitman Mountains, Hudspeth County, Texas in Price, J.G., Henry, C.D., Parker, D.F., and Barker, D.S., eds., Igneous geology of Trans-Pecos Texas, field trip guide and research ar
Shannon, W.M. and Goodell, P.C., 1986, Lithochemistry of intrusive rocks of the Quitman-Sierra Balnce igneous complex, Hudspeth County, Texas in Price, J.G., Henry, C.D., Parker, D.F., and Barker, D.S., eds., Igneous geology of Trans-Pecos Texas, field t
Huffington, R.M., 1943, Geology of the northern Quitman Mountains, Trans-Pecos Texas: Geological Society of America Bulletin, v. 54, p. 997-1048.
Counties Hudspeth