Eagle Mountains caldera volcanic rocks (TXOGe;0)

State	Texas
Name	Eagle Mountains caldera volcanic rocks
Geologic age	Phanerozoic \| Cenozoic \| Tertiary \| Oligocene
Original map label	Oe
Comments	Total of about 3,000-4,000 ft of eruptive rocks: lower rhyolite, a sequence of tuff, flow breccia, volcanic breccia, extrusive and intrusive rhyolite, with sedimentary rocks at base, thickness more than 1,000 ft. Trachyte porphyry--hard, compact, weathers to angular blocks, thickness as much as approximately 750 ft. Upper rhyolite--rhyolite including an upper volcanic breccia, flow breccia, and patches of basal conglo.; volc. breccia fragments of volc. rock, quartzite, and limestone in aphanitic matrix, white to lt. gray; rhyolite, aphanitic, comapct, brittle, intensely fractured, thickness 1,500 to 2,000 ft at Eagle Bluff.
Primary rock type	rhyolite
Secondary rock type	trachyte
Other rock types	conglomerate; tuff; volcanic breccia (agglomerate)
Lithologic constituents	Major Igneous > Volcanic > Felsic-volcanic > Rhyolite (Flow) Minor Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, tuff) Igneous > Volcanic > Felsic-volcanic > Trachyte (Pyroclastic, tuff)
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, 1979, Marfa Sheet, Geologic Atlas of Texas: Bureau of Economic Geology and The University of Texas at Austin, scale 1:250,000.
Geographic coverage	Culberson - Hudspeth - Jeff Davis