Uvalde Gravel (TXQTu;0)

State	Texas
Name	Uvalde Gravel
Geologic age	Pliocene to Pleistocene
Lithologic constituents	Major Unconsolidated > Coarse-detrital > Gravel (Bed)
Comments	Caliche-cemeneted gravel; some boulders up to 1 ft diameter; well-rounded cobbles of chert, some cobbles of quartz, limestone, and igneous rock; present on topographic divides and high areas not associated with present drainage; extensive deposits in Medina and Uvalde Cos. Thickness from several feet of gravel lag to about 30 ft. According to Moore and Wermund (1993): Alluvial sandy gravel--pale-brn, lt.-yell-brown, and reffish-brn sandy gravel and gravelly sand containing small proportions of silt and clay. Typically cemented by secondary calcium carbonate, ranging from hard calcrete that will not slake in water to soft calcareous zones; depth of cemented zone 0.2-2 m. Abdt, well-rounded pebbles and cobbles of chert, quartz, and limestone; minor igneous rock; some boulders. Caps drainage divides, upland flats, and rounded ridges 30-75 m above streams. Extensive upland depodist on high alluvial terraces along Rio Grande and in northern Nueces Plains. Thickness 1-6 m.
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. Bureau of Economic Geology, 1974, San Antonio Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, 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	NGMDB product page for 68390
Counties	Atascosa - Bexar - Dimmit - Frio - Kinney - La Salle - Live Oak - McMullen - Maverick - Medina - Starr - Terrell - Uvalde - Val Verde - Webb - Zapata - Zavala

State

Texas

Name

Uvalde Gravel

Geologic age

Pliocene to Pleistocene

Lithologic constituents

Major

Unconsolidated > Coarse-detrital > Gravel (Bed)

Comments

Caliche-cemeneted gravel; some boulders up to 1 ft diameter; well-rounded cobbles of chert, some cobbles of quartz, limestone, and igneous rock; present on topographic divides and high areas not associated with present drainage; extensive deposits in Medina and Uvalde Cos. Thickness from several feet of gravel lag to about 30 ft. According to Moore and Wermund (1993): Alluvial sandy gravel--pale-brn, lt.-yell-brown, and reffish-brn sandy gravel and gravelly sand containing small proportions of silt and clay. Typically cemented by secondary calcium carbonate, ranging from hard calcrete that will not slake in water to soft calcareous zones; depth of cemented zone 0.2-2 m. Abdt, well-rounded pebbles and cobbles of chert, quartz, and limestone; minor igneous rock; some boulders. Caps drainage divides, upland flats, and rounded ridges 30-75 m above streams. Extensive upland depodist on high alluvial terraces along Rio Grande and in northern Nueces Plains. Thickness 1-6 m.

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.

Bureau of Economic Geology, 1974, San Antonio Sheet, Geologic Atlas of Texas, University of Texas, Bureau of Economic Geology, 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

NGMDB product page for 68390

Counties

Atascosa - Bexar - Dimmit - Frio - Kinney - La Salle - Live Oak - McMullen - Maverick - Medina - Starr - Terrell - Uvalde - Val Verde - Webb - Zapata - Zavala