LOCATION DANT TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, hyperthermic Aridic Haplustolls
TYPICAL PEDON: Dant clay loam - rangeland.
(Colors are for dry soil unless otherwise stated.)
A--0 to 11 inches; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; hard, friable; many fine roots; 1/8 to 1/4 inch crust on surface that is slightly lighter colored and more sandy; calcareous; moderately alkaline; clear smooth boundary. (10 to 18 inches thick)
Bw--11 to 19 inches; grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; moderate fine and medium blocky and subangular blocky structure; very hard, firm; many fine roots; few fine pores and roots channels; some surfaces of peds have shiny faces; vertical cracks 1/4 to 5/16 inch wide occur; calcareous; moderately alkaline; gradual wavy boundary. (5 to 22 inches thick)
Bz--19 to 41 inches; grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; slightly lighter colored than Bw above; weak prismatic parting to moderate medium and coarse blocky structure; extremely hard, very firm; few roots in upper part but less with depth; roots are mainly between peds; few fine pores; shiny faces on peds presumed to be pressure planes; vertical cracks 1/4 to 5/16 inch wide and 4 to 12 inches apart; few small slickensides in lower part; organic staining on few faces of peds; few threads of segregated calcium carbonate; saline; calcareous; moderately alkaline; gradual wavy boundary. (0 to 22 inches thick)
Bkz--41 to 50 inches; light brownish gray (10YR 6/2) clay, grayish brown (10YR 5/2) moist; weak coarse blocky structure; very hard, very firm; very few fine roots and root channels; contains an estimated 2 percent by volume of soft lumps of calcium carbonate to 1/4 inch diameter; few narrow tongues filled with darker colored clay; saline; calcareous; moderately alkaline; diffuse wavy boundary. (0 to 12 inches thick)
Ckyz--50 to 72 inches; very pale brown (10YR 7/3) clay, pale brown (10YR 6/3) moist; structureless; very hard, very firm; contains many more visible quartz grains than above horizons; contains a few soft lumps of calcium carbonate, especially in upper part, and a few gypsum crystals; few streaks or narrow tongues filled with darker clay; saline; calcareous; moderately alkaline.
TYPE LOCATION: Maverick County, Texas; about 24 miles north, 57 degrees east of Eagle Pass; in rangeland 150 feet north of Texas Highway 57 and 3.5 miles southwest of Maverick-Zavala County line.
RANGE IN CHARACTERISTICS: Solum thickness is 24 to 60 inches. The soil is slightly or moderately affected by salinity which increases with depth.
The A horizon is grayish brown (10YR 5/2), dark grayish brown (10YR 4/2), very dark grayish brown (10YR 3/2), brown (10YR 5/3), or dark brown (10YR 3/3, 4/3). It is sandy clay loam, clay loam, or clay.
The B horizon is grayish brown (10YR 5/2; 2.5Y 5/2), dark grayish brown (10YR 4/2; 2.5Y 4/2), or brown (10YR 4/3, 5/3). It is clay loam or clay; silicate clay content ranges from 28 to 35 percent. Carbonate clay content is 5 to 15 percent. Calcium carbonate equivalent is 15 to 35 percent. The Bz and Bkz horizons are lacking in some pedons.
The C horizon is light yellowish brown (10YR 6/4), pale brown (10YR 6/3), very pale brown (10YR 7/3, 7/4), light gray (10YR 7/2; 2.5Y 7/2), or light brownish gray (10YR 6/2; 2.5Y 6/2). It is clay or sandy clay. Visible calcium carbonate ranges from few to 10 percent by volume and visible gypsum crystals range from a few to 20 percent by volume.
COMPETING SERIES: These are the Garceno, Hidalgo, Ingram, Maverick, Pimer, Sinton series. Garceno, Ingram, and Maverick soils have more than 35 percent silicate clay in the 10- to 40- inch control section. Hidalgo soils have calcic horizons at depths of less than 40 inches. Pimer and Sinton soils have mollic epipedons more than 20 inches thick. In addition, Pimer soils have fine-silty control sections.
GEOGRAPHIC SETTING: These soils are on nearly level to gently sloping uplands. Surfaces mainly are plane to convex but some are concave. Gradients are dominantly 0.5 to 2.5 percent but range from 0 to 5 percent. The soil formed in calcareous marine clays stratified with sandstone. Climate is hot and dry subhumid to semiarid. Average annual precipitation is 20 to 26 inches, mean annual temperature ranges from 70 to 74 degrees F., and Thornthwaite annual P-E indices range from 24 to 34.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Catarina, Montell, Monteola, and Uvalde soils in addition to the competing Garceno and Maverick soils. Catarina, Montell, and Monteola soils have intersecting slickensides and gilgai microrelief. Uvalde soils have calcic horizons at depths of less than 40 inches. These soils occur on similar surfaces.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; slow permeability.
USE AND VEGETATION: Used almost exclusively for range. A few areas are cultivated mainly to small grain and grain sorghums in the eastern part of its occurrence. Rangeland has moderate overstory of meqsuite that is stunted and multiple branched from the crown, guayacan, blackbrush, whitebrush, spiny hackberry, pricklypear cactus, and a ground cover of tobosagrass, bristlegrass, pink pappusgrass, Hall's panicum, red grama, and threeawn grass.
DISTRIBUTION AND EXTENT: Rio Grande Plain of south Texas. The soil is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Uvalde County, Texas; 1970.
REMARKS: These soils would formerly have been classified in the Reddish Chestnut great soil group.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 11 inches.
Cambic horizon - 11 to 50 inches.
ADDITIONAL DATA: Lincoln Laboratory sample nos. 68L074.