LOCATION SINGLETON TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Udic Paleustalfs
TYPICAL PEDON: Singleton fine sandy loam--pasture. (Colors are for moist soil unless otherwise stated.)
A--0 to 5 inches; light brownish gray (10YR 6/2) fine sandy loam, light gray (10YR 7/2) dry; weak fine subangular blocky structure; very hard, friable; many fine and medium roots, few coarse roots; few siliceous pebbles; strongly acid; abrupt smooth boundary. (3 to 8 inches thick)
E--5 to 9 inches; pale brown (10YR 6/3) fine sandy loam, very pale brown (10YR 7/3) dry; weak fine subangular blocky structure; hard, friable; many fine and medium roots, few coarse roots; few siliceous pebbles; strongly acid; abrupt smooth boundary. (0 to 6 inches thick)
Bt1--9 to 20 inches; dark brown (10YR 4/3) clay, brown (10YR 5/3) dry; few fine distinct yellowish brown (10YR 5/6) redox concentrations; moderate medium prismatic structure parting to moderate medium angular blocky; extremely hard, extremely firm; few fine roots; thick continuous dark grayish brown (10YR 4/2) clay films on surface of prisms; electrical conductivity is 0.3 mmho/cm; very strongly acid; clear smooth boundary. (0 to 8 inches thick)
Bt2--20 to 32 inches; brown (10YR 5/3) clay, pale brown (10YR 6/3) dry; few fine distinct (7.5YR 5/4) redox concentraations; weak medium prismatic structure parting to moderate medium angular blocky; extremely hard, extremely firm; few fine roots; thick continuous grayish brown (10YR 5/2) clay films on surface of prisms; few fine masses of barite; electrical conductivity is 0.7 mmho/cm; very strongly acid; gradual smooth boundary. (6 to 20 inches thick)
BCt--32 to 38 inches; brown (10YR 5/3) clay loam, pale brown (10YR 6/3) dry; with common medium distinct very pale brown (10YR 7/4) redox concentrations; weak medium subangular blocky structure; very hard, very firm; few fine roots; few patchy clay films; few gypsum crystals; few fine masses of barite; electrical conductivity is 2.0 mmhos/cm; moderately acid; clear smooth boundary. (0 to 12 inches thick)
Cr--38 to 60 inches; light gray (10YR 7/2) weakly cemented sandstone containing thin layers of sandy clay loam, white (10YR 8/2) dry; massive and horizontally bedded; very hard, very firm; few fine masses of barite.
TYPE LOCATION: Grimes County, Texas; from the intersection of Texas Highway 30 and FM 244 at Carlos, west 2.6 miles on Texas Highway 30, south 1.4 miles on county road. Site is 100 feet east of road in wooded rangeland
RANGE IN CHARACTERISTICS: Solum thickness and depth to a paralithic contact ranges from 20 to 40 inches. Weighted average clay content of the control section ranges from 35 to 45 percent.
The combined thickness of the A and E horizons is 5 to 12 inches. The A and E horizons have hue of 10YR and 7.5YR, value of 4 to 8, and chroma of 2 or 3. Texture is fine sandy loam or loam. Reaction ranges from strongly acid to slightly acid.
The Bt horizon has hue of 7.5YR to 2.5Y, value of 4 to 6, and chroma of 3 or 4. Surfaces of some peds have chroma of 2. It has few to common brownish or reddish redox concentrations. The texture is commonly clay but ranges to clay loam or sandy clay in the lower part of some pedons. Electrical conductivity ranges from 0.5 to 4.0 mmhos/cm. The reaction is very strongly acid to moderately acid.
The BCt or B/C horizon has colors in shades of brown or gray. Redox concentrations in shades of red or brown range from none to common. The texture is sandy clay loam or clay loam with clay content of 25 to 40 percent. Fragements of slightly weathered siltstone, sandstone or mudstone range from none to common. Masses of barite range from none to about 3 percent. Crystals of gypsum are in most pedons, but range from none to about 10 percent of some pedons. Some pedons contain a few concretions of calcium carbonate. Electrical conductivity ranges from 0.5 to 4.0 mmhos/cm. Reaction ranges from very strongly acid to neutral.
The Cr horizon is weakly cemented tuffaceous sandstone, siltstone, or mudstone interbedded with clay loam or sandy clay loam. Some pedons contain lenses or strata of weathered tuffaceous shale that has clay texture. Concretions of calcium carbonate range from none to few.
COMPETING SERIES: These are the Cadell, Chazos, Gredge, Payne, and Zack. Similar soils include Arol, Burlewash, Lufkin, Mabank, and Zulch series. Arol soils have color values less than 3.5 in the Bt horizon. Cadell, Chazos, Gredge, and Payne soils have sola thicker than 40 inches. Burlewash soils are well drained and ultic. Lufkin, Mabank, and Zulch soils do not have a paralithic contact of soft bedrock.
GEOGRAPHIC SETTING: Singleton soils are mainly on very gently sloping uplands with slopes of 1 to 3 percent. However, the slope ranges from 0 to 5 percent. These soils formed in tuffaceous sandstone, mudstone, and siltstone of the Jackson geologic group of Teritary age. The climate is warm humid to warm subhumid. The mean annual temperature ranges from 66 to 70 degrees F and mean annual precipitation ranges from 34 to 40 inches. Frost free days range from 260 to 280 days and elevation ranges from 200 to 500 feet. Thornthwaite P-E indices range from 50 to 66.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Arol, Burlewash, Elmina, Falba, Gomery, Shiro and Tonkavar. Arol and Falba are on similar landscapes. Burlewash soils are above on low hills and sideslopes along drainageways. Elmina and Gomery soils are on higher positions and have sandy surface horizons 20 to 40 inches thick. Shiro soils are on similar positions. They have sandy surface horizons 10 to 20 inches thick. Tonkavar soils are above on slopes and ridges and have sandy surface horizons over 40 inches thick
DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is very slow. Runoff is low for 0 to 1 percent slopes, medium for 1 to 3 percent slopes, and high for 3 to 5 percent slopes. A perched water table is above the Bt horizon for very brief periods following heavy rains mainly in winter and spring.
USE AND VEGETATION: Most areas are in native pasture or improved pasture. A few areas are planted to small grain or ryegrass for winter pasture for cattle and/or deer. Native vegetation overstory consists of post oak, blackjack oak, red cedar and elm. The understory consists of yaupon, greenbriar, little bluestem, threeawn, paspalum sp., bristlegrass, purpletop, broomsedge, and panicum sp. Pine trees have encroached in a few areas.
DISTRIBUTION AND EXTENT: In MLRA 87A, Southern Texas Claypan. The Singleton series is mainly distributed in East Central Texas. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Grimes County, Texas; 1988
REMARKS: These soils do not have an aquic moisture regime. Classification change from Aeric Albaqualfs is the result of interpretation that low chroma matrix is due, in part, to lithochromic influences.(6/90) Field observations, landscape position and climate indicate the soil is not typically saturated for extended periods. (5/93)
The Singleton soils have formerly been included in the Falba series
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 9 inches (A and E horizons)
Abrupt textural change at 9 inches, from E to Bt horizon
Argillic horizon - 9 to 38 inches (Bt1, Bt2, and BCt horizons)
Paralithic contact - at 38 inches
ADDITIONAL DATA: Data from soil samples run for Texas Municipal Power Agency local lab analysis