Wiley Mountain caldera volcanic rocks

Wiley Mountain caldera volcanic rocks
State Texas
Name Wiley Mountain caldera volcanic rocks
Geologic age Eocene
Lithologic constituents
Major
Igneous > Volcanic > Felsic-volcanic > Trachyte (Flow)
Minor
Igneous > Volcanic > Felsic-volcanic > Quartz-trachyte (Flow)
Comments in Wiley Mts. fr top down includes Zopilote Breccia, trachyte lithic flow-breccia, thickness about 150 ft; Means Trachyte, aphanitic, vesicular, hard, dk gray, thickness 530 ft; Fairbury Trachyte, from top down; lapilli tuff and ashy tuff grading dow to agglomerate of trachytic felsophyre in an ashy matrix, anorthoclase trachyte as much as 100 ft thick, porphyritic plagioclase trachyte up to 390 ft tick, and a basal flow breccia member, thickness 140 ft K-Ar age 36.9+-0.8 Ma; Moon Trachyte has upper platy quartz trachyte 350 ft thick, and lower aphanitic quartz trachyte up to 70 ft thick.
Stratigraphic units Garren Group, Zopilote Breccia, Means Trachyte, Fairbury Trachyte, Moon Trachyte
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.

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 Culberson - Jeff Davis