Duff Formation, Decie Member from Paisano caldera

Duff Formation, Decie Member from Paisano caldera
State Texas
Name Duff Formation, Decie Member from Paisano caldera
Geologic age Early Oligocene
Lithologic constituents
Major
Igneous > Volcanic > Felsic-volcanic > Trachyte
Minor
Igneous > Volcanic > Felsic-volcanic (Pyroclastic-ash flow)
Incidental
Sedimentary > Clastic > Conglomerate
Comments volcanic rock from Paisano volcano, 5 units, young to old: 1) lava, agglomeratic tuff, conglomerate, ash-flow tuff. 2) ash-flow tuff. 3) aphyric to sl. porphyritic quartz trachyte 4) yellow aggomeratic tuff interlayered with two minor quartz trachyte ash-flow sheets 5) rhyolite lava
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, 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.

NGMDB product
Counties Brewster - Jeff Davis - Presidio