LOCATION CARADAN TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Udertic Argiustolls
TYPICAL PEDON: Caradan silty clay--rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; very dark brown (10YR 2/2) silty clay, very dark grayish brown (10YR 3/2) dry; moderate very fine subangular blocky structure; very hard, firm, many fine and medium roots; few fine siliceous pebbles; neutral; clear wavy boundary. (4 to 8 inches thick)
Bt--4 to 13 inches; dark brown (7.5YR 3/2) clay, dark brown (7.5YR 4/2) dry; moderate medium prismatic structure parting to moderate medium angular blocky; very hard, firm, common fine and medium roots; few fine siliceous pebbles; common pressure faces; few small slickensides; neutral; gradual wavy boundary. (5 to 15 inches thick)
Btss--13 to 19 inches, dark brown (7.5YR 3/2) clay, dark brown (7.5YR 4/2) dry; moderate prismatic structure parting to moderate medium angular blocky; very hard, firm; common fine and medium roots; few fine siliceous pebbles; common pressure faces; common small slickensides; neutral; clear wavy boundary. (0 to 15 inches thick)
Btkss--19 to 26 inches; dark brown (7.5YR 3/4) silty clay, dark brown (7.5YR 4/4) dry; weak medium prismatic structure parting to moderate medium subangular blocky; very hard, firm; few fine and medium roots; few fine siliceous pebbles; common pressure faces; common white slickensides; about 10 percent white (10YR 8/2) vertically oriented, soft carbonate segregations; mildly alkaline; clear smooth boundary. (5 to 10 inches thick)
2Bk1--26 to 63 inches; yellowish red (5YR 5/8) silt loam, reddish yellow (7.5YR 7/6) dry moderate fine subangular blocky structure; hard, friable; few fine and medium roots; few fine siliceous pebbles; about 30 percent white (10YR 8/2) vertically oriented, soft carbonate segregations; moderately alkaline; gradual smooth boundary. (20 to 40 inches thick)
2Bk2--63 to 80 inches yellowish red (5YR 4/6) silty clay loam; few fine faint strong brown mottles; moderate fine subangular blocky structure; hard, friable; few fine roots; few fine siliceous pebbles; about 10 to 15 percent white (10YR 8/1) vertically oriented, soft carbonate segregations; some segregations have weakly indurated centers; moderately alkaline.
TYPE LOCATION: Hamilton County, Texas; from the intersection of U.S. Highway 84 and U.S. Highway 281 in Evant: 8.4 miles west on U.S. Highway 84, 2.4 miles north on county road, 1.8 miles west on ranch road, 2,000 feet north in rangeland.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80 inches. Chert fragments of gravel and cobble size range from few to about 15 percent of the soil surface. Cracks more than 1 cm wide extend to depths of 20 to 30 inches are at some seasons during most years. The soil is slightly acid to mildly alkaline and noncalcareous in the upper part and is mildly alkaline to moderately alkaline and calcareous in the lower Bt horizon. Soft concretions, films, and threads occur at depths below 12 inches but commonly within 28 inches. The COLE is 0.07 to 0.13 or more in some horizons or horizons 20 or more inches thick.
The A horizon has hue of 5YR to 10YR, value of 2 to 4, and chroma of 1 to 3. The texture is silty clay, clay, or clay loam.
The Bt horizons have hue of 5YR or 7.5YR, value of 3 to 5, and chroma of 2 to 6. Vertically oriented concretions, films, and threads of calcium carbonate range from 3 to 15 percent by volume in the lower part of the Bt. The average clay content ranges from 50 to 60 percent.
The 2Bk horizons have hue of 5YR to 10YR, value of 3 to 8, and chroma of 2 to 6. Vertically oriented concretions, films, and threads of calcium carbonate range from 15 to 40 percent by volume. Textures are loam, silt loam, clay loam, or silty clay loam.
COMPETING SERIES: These are the Benchley, Durant, Foraker, and Flatonia series in the same family and the similar Culp, Halletsville, Lofton, Normangee, Tabler, Tarpley, Topia, and Speck series. Benchley soils are formed in clayey marine sediments, contain gray mottles in the lower part of the argillic horizon and are not effervescent within 30 inches of the surface. Flatonia soils have sola thickness 40 to 60 inches over soft bedrocks. Durant and Tabler soils have hues yellower than 10YR, also Tabler soils have a mollic epipedon thicker than 20 inches. Foraker soils have sola less than 40 inches thick and are calcareous throughout. Culp, Lofton, and Topia soils have mixed mineralogy, also Topia soils have more than 60 percent clay in the control section. Halletsville soils have an abrupt textural change between the A and Bt horizons. Normangee soils do not have a mollic epipedon. Tarpley and Speck soils have lithic contacts.
GEOGRAPHIC SETTING: Caradan soils are on ancient stream terraces and erosional uplands. Slopes are mostly less than 2 percent, but range to 3 percent. The soil formed in a mantle of clay over calcareous, loamy earth. The mean annual temperature ranges from 64 to 67 degrees F. Frost free days range from 230 to 240, and the elevation ranges from 1000 to 1700 feet above sea level. The annual precipitation ranges from 26 to 28 inches, and the Thornthwaite annual P-E indices are 42 to 50.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cisco, Doss, Evant, Nuff, Pidcoke, Real, Seawillow, and Topsey series. The deep, sandy surfaced Cisco soils, the deep, loamy Topsey soils, and the shallow, loamy Pidcoke soils, and the deep, stony Nuff soils are *upslope on gently sloping positions. The shallow, loamy Doss and Real soils are below on sideslopes above drains. The deep, loamy Seawillow soils are below on similar or slightly lower stream terraces. The shallow, loamy Evant soils are on similar positions.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; very slow permeability.
USE AND VEGETATION: Mainly rangeland but a few areas are farmed to small grain and grain sorghum. Native vegetation includes Texas wintergrass, sideoats grama, bluestem, and scattered post oak, live oak, white shin oak, blackjack, and juniper trees.
DISTRIBUTION AND EXTENT: In the Grand Prairie MLRA of central Texas. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Brown and Mills Counties, TX; 1975
ADDITIONAL DATA: Hamilton County samples number S84TX-193-001: 2075-2081 (TABS), and S84TX-193-(01-03): C902-C904 (TAES); and Mills County samples number S84TX-333-01: C901 (TAES); and NSSL samples S72TEX-167-1-(1-5): 72L1006-72L1010.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 0 to 19 inches.
Argillic horizon - The zone from 4 to 26 inches.
Calcic horizon - The zone from 26 to 80 inches.
Vertic properties - Very high shrink-swell properties in the zone from 4 to 26 inches.