Devils Graveyard volcanic rocks (TXOGEOg;0)

State	Texas
Name	Devils Graveyard volcanic rocks
Geologic age	Phanerozoic \| Cenozoic \| Tertiary \| Eocene Oligocene
Original map label	OEg
Comments	Presidio and Brewster Cos., SW TX. Bandera Mesa member (upper member) basalt flow that underlies 32 m.y-old Mitchell Mesa Rhyolite. Bandera Mesa Mbr gave 33.2 and 33.7 +_ m.y. ages. Middle member is air-fall tuff dated at 42.8 m.y. Eocene and lower member tuffaceous sediment, air-fall tuff, and basalt flows dated 43.9 to 53.6 +_ m.y. Eocene. (Henry and others, 1986)
Primary rock type	tuff
Secondary rock type	basalt
Other rock types
Lithologic constituents	Minor Igneous > Volcanic > Felsic-volcanic (Pyroclastic, air fall) 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, 1982, Fort Stockton Sheet, Geologic Atlas of Texas, University of Texas at Austin, scale 1:250,000. 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.
Geographic coverage	Brewster - Presidio