Unconsolidated > Coarse-detrital > Gravel (Colluvial)
|Comments||Composition related to rock types in nearby area; upper part: fragments of subrounded tuff, trachyte, basalt, and ignimbrite; lower part; subrounded to rounded quartzite and limestone pebbles and cobbles probably derived from basal conglomerate of Colmena Formation; occures southwest of Van Horn Mtns. in northern Rim Rock County; thickness up to approx.400 ft.|
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.
|Counties||Culberson - Hudspeth - Jeff Davis - Presidio|