|Geologic age||Phanerozoic | Paleozoic | Carboniferous Pennsylvanian Permian|
|Comments||Overlies Canyon Grp. Basal formation of Bowie Group (new), Hentz (1988). Continental and minor paralic strata on Bend arch and Ft Worth syncline (Young, Jack, Clay, Montague Cos., TX) Sandst., mudst., conglomerate, coal, scarce thin limest. Easternmost outcrop, fluvial and minor fluvial-deltaic sandst. and chert-pebbly conglomerates form marker beds. Markley contains 15 sandst. members which occur as mappable stacked bodies and horizontally contiguous belts, separated by thin mudstone zones. Mudst. contains sandst. and siltst. lentils and discontinuous seams of subbituminous coal and carbonaceous shale (Newcastle Coal and others). In lower part are thin beds of weathered and fissile subbituminous coal. Ranges in thickness 320-600 ft.|
|Primary rock type||sandstone|
|Secondary rock type||mudstone|
|Other rock types||conglomerate; coal; limestone|
Sedimentary > Clastic > Sandstone (Bed)
Sedimentary > Clastic > Mudstone > Shale > Black-shale (Bed)
Sedimentary > Clastic > Conglomerate (Bed)
Sedimentary > Coal > Sub-bituminous (Bed)
Sedimentary > Clastic > Mudstone > Claystone (Bed)
Sedimentary > Carbonate > Limestone (Bed)Crystal Falls Limestone in so. Young Co, 1-2 ft in discontinuous otcps.
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
Bureau of Economic Geology, 1987, Wichita Falls-Lawton Sheet, Geologic Atlas of Texas: University of Texas at Austin, Bureau of Economic Geology, scale 1:250,000.
|Counties||Archer - Clay - Culberson - Jack - Montague - Throckmorton - Young|