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Delaho and Rawls Formations, undivided

Delaho and Rawls Formations, undivided NOTE: This unit is represented within the map unit explanation of (Geol. Map of Texas, 1992, Bur. Econ. Geol.) but does not occur on the map and is NOT included in the spatial data.
State Texas
Name Delaho and Rawls Formations, undivided
Geologic age Phanerozoic | Cenozoic | Tertiary | Oligocene Miocene
Comments sandstone and conglomerate, pebbles dominantly Tule Mountain Trachyandesite, basalt pebbles dominant in upper part to the south (in Emory Peak-Presidio Sheet (1979)); sandst. composed mostly of volcanic rock fragments; festoon crossbedding well developed; Smoky Creek Mbr. thickness as much as 1,100 ft. Lower unnamed member thickness about 1,100 ft, total about 2,200 ft thick. Rawls Fm--conglo., sandst., and tuff; basalt; bolson fill; trachyte; trachyandesite; latite porphyry; trachybasalt porphyry; ash-flow tuff. Rawls Fm as much as 1,200 ft thick.
Primary rock type sandstone
Secondary rock type conglomerate
Other rock types trachyte; trachyandesite; latite; trachybasalt; basalt; ash-flow tuff; mudstone
Lithologic constituents
Minor
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Flow)ash-flow tuff and tuffaceous sediments
Igneous > Volcanic > Felsic-volcanic > Trachyte (Flow)ash-flow tuff and tuffaceous sediments
Incidental
Igneous > Volcanic > Felsic-volcanic > Latite (Flow)ash-flow tuff and tuffaceous sediments
Igneous > Volcanic > Mafic-volcanic > Basalt (Flow)ash-flow tuff and tuffaceous sediments
Igneous > Volcanic > Mafic-volcanic > Basaltic-andesite (Flow)ash-flow tuff and tuffaceous sediments
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, Emory Peak--Presidio Sheet, Geologic Atlas of Texas, University of Texas at Austin.