LOCATION SEARSVILLE TXEstablished Series
TAXONOMIC CLASS: Clayey, mixed, active, thermic Lithic Haplustepts
TYPICAL PEDON: Searsville clay, on convex 2 percent slope, in cropland.
(Colors are for dry soil unless otherwise stated.)
Ap--0 to 7 inches; reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; moderate fine subangular blocky structure; hard, firm; common fine roots; few fine pores; few concretions of calcium carbonate; few fragments of limestone; moderately
alkaline, calcareous; abrupt smooth boundary. (4 to 8 inches
thick)
B21--7 to 14 inches; red (2.5YR 4/6) clay, dark red (2.5YR
3/6) moist; moderate medium blocky structure; very hard, very
firm; few vertical streaks of reddish brown clay; common
concretions of calcium carbonate; moderately alkaline, calcareous; gradual wavy boundary. (3 to 10 inches thick)
B22ca--14 to 18 inches; yellowish red (5YR 5/6) clay,
yellowish red (5YR 4/6) moist; moderate fine blocky and subangular blocky structure; hard, very firm; many soft bodies of calcium carbonate common concretions of calcium carbonate; moderately alkaline, calcareous; abrupt wavy boundary. (3 to 5 inches thick)
R--18 to 22 inches; limestone bedrock that is coarsely
fractured in the upper part.
TYPE LOCATION: Bosque County, Texas; about 12 miles south of Clifton. From the red light on Texas Highway 6 in Clifton, Texas, 3.95 miles south on Texas Highway 6 to the intersection with Farm Road 2602; then west and south 9.6 miles on Farm Road 2602; then northwest on county road 1.2 miles; then west 130 feet of road in
old abandon field.
RANGE IN CHARACTERISTICS: Thickness of the solum and depth to the lithic contact ranges from 10 to 20 inches. Coarse fragments, of gravel and cobble size, range from a few to 25 percent on the
surface and in the soil. Coarse fragments are mostly limestone
with a small amount of chert and ironstone. The dry soil has
cracks 1 to 4 cm wide to depths of 25 to 45 cm. The control
section ranges from 20 to about 30 percent calcium carbonate equivalent.
The A horizon is dark brown (7.5YR 4/2, 3/2), dark reddish brown
(5YR 3/4, 3/3), reddish brown (5YR 4/4, 4/3), and dark reddish
brown (5YR 3/3). A horizons with moist values and chromas of less than 3.5 are less than 7 inches thick. The texture ranges from
clay to silty clay.
The fine-earth textures in the B2 horizons are clay or silty clay, with a clay content of 40 to 60 percent. The B21 horizon is dark reddish brown (2.5YR 3/4), red (2.5YR 4/6), and dark red (2.5YR
3/6). The B22ca horizon is dark reddish brown (2.5YR 3/4), reddish brown (2.5YR 4/4; 5YR 5/4, 4/4), yellowish red (5YR 5/6, 4/6), and red (2.5YR 5/6, 4/6). The B22ca horizon contains 5 to 25 percent limestone fragments 2 mm to 2 inches in diameter.
The R layer is platy to massive limestone that is fractured in the upper part.
COMPETING SERIES: These include the
Cordell,
Hensley,
Keese,
Owens,
Purves,
Speck, and
Tarpley series. Hensley soils have argillic horizons. Cordell and Keese soils have loamy control sections. Owens soils have paralithic contact to shale. Purves, Speck, and Tarpley soils have mollic epipedons. In addition,
Speck and Tarpley soils have argillic horizons.
GEOGRAPHIC SETTING: Searsville soils are on gently sloping
uplands. Slope gradients are 1 to 5 percent. The soil formed in calcareous clayey sediments over hard limestone of Lower
Cretaceous Age. Climate is moist subhumid. The mean annual temperature is 64 degrees to 68 degrees F. Average annual precipitation ranges from 30 to 35 inches and the Thornthwaite P-E index ranges from 46 to 56.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Purves series and the
Denton,
Eckrant,
Mosheim, and
San Saba series. All
of these soils are in similar positions. Denton soils have mollic epipedons and sola 20 to 40 inches thick. Eckrant soils have
mollic epipedons, montmorillonitic mineralogy and more than 35 percent rock fragments in the soil. Mosheim soils have mollic epipedons and sola 40 to 60 inches thick. San Saba soils have chromas of less than 1.5 throughout the upper 12 inches,
intersecting slickensides, and sola 24 to 40 inches thick.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff, slow permeability.
USE AND VEGETATION: Used mostly for small grain, grain sorghum, forage sorghums and cotton. Native vegetation consists of short
and mid grasses, with scattered live oak and mesquite trees.
DISTRIBUTION AND EXTENT: Central Texas, mostly along the southern and eastern edge of the Grand Prairie land resource area. These soils are of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Bosque County, Texas; 1977.
REMARKS: These soils would have been classified in the Lithosol great soil group. They were formerly mapped in the Tarpley
series.
ADDITIONAL DATA: Local particle size (hydrometer) data and
Atterburg Limits data from Texas Highway Department.
Horizon Thickness S Si
C LL PI
Ap 0-7@ 14 31
55 62 37
B21 7-14@ 16 26
58 60 36
B22ca 14-18@ 18 26
56 56 35