high gravel deposits (TXQhg;0)

State	Texas
Name	high gravel deposits
Geologic age	Phanerozoic \| Cenozoic \| Quaternary \| Pleistocene
Original map label	Qhg
Comments	In north, central, and south Texas including Quaternary for all of west Texas- gravel commonly exposed to the surface, in northwest part of Austin Sheet (1974) composed of an upper silty clay unit good for crop production and a lower coarse unit that yields some water (possibly correlates with the Onion Creek Marl). In Waco Sheet (1970) Caliche-cemented cobbles of chert as large as 5 inches in size, pebbles of variegated quartzite, limestone, chert, and quartz; thickness up to 10 ft In East Texas and Gulf Coast to Rio Grande- in SE part of Austin Sheet (1974) gravel commonly exposed to the surface; northwestward, unit composed of an upper silty clay unit good for crop production and a lower coarse unit that yields some water (possibly correlates with the Onion Creek Marl). On Wichita Falls-Lawton Sheet (1987) unit is limestone gravel, sand, and silt; mostly gravel, sandy, silty, in part massive, large-scale crossbeds, mostly loosely consolid. to unconsolidated, locally well-indurated by fine-grained limestone; clasts granules to boulders chiefly ls. with minor quartzite, milky quartz, and sandst and mudstone. Locally in at least 2 topo levels, wedge-shaped in cross section. Thickness of limestone gravel 5-25 ft.
Primary rock type	gravel
Secondary rock type	silt
Other rock types	sand
Lithologic constituents	Major Unconsolidated > Coarse-detrital > Gravel (Bed) Minor Unconsolidated > Coarse-detrital > Sand (Bed) Incidental Unconsolidated > Fine-detrital > Silt (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, 1974, Austin Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, scale 1:250,000. Bureau of Economic Geology, 1970, Waco Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, scale 1:250,000. 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.
Geographic coverage	Archer - Bastrop - Baylor - Bell - Brazos - Brown - Burleson - Coleman - Concho - Fayette - Gillespie - Hays - Irion - Lee - Leon - Limestone - McCulloch - McLennan - Madison - Milam - Robertson - Runnels - San Saba - Throckmorton - Tom Green - Travis - Washington - Williamson - Young