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Olmos Formation

Olmos Formation
State Texas
Name Olmos Formation
Geologic age Phanerozoic | Mesozoic | Cretaceous-Late [Gulfian]
Comments clay, sandstone, coal, and fire clay; irreg. stratified, interfingering lenses of ss and clay, chief coal seam about 6 ft thic; poorly exposed unit; thickness 400-500 ft. Lower part of Navarro Grp.
Primary rock type clay or mud
Secondary rock type sandstone
Other rock types coal
Lithologic constituents
Major
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Mudstone > Claystone (Bed)
Minor
Sedimentary > Coal > Lignite (Bed)
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, 1977, Del Rio Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, scale 1:250,000.
Bureau of Economic Geology, 1976, Crystal City-Eagle Pass Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, scale 1:250,000.
Counties Maverick