LOCATION FOURSIXES TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Typic Haplustalfs
TYPICAL PEDON: Foursixes clay loam--rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 4 inches; brown (7.5YR 5/3) clay loam, dark brown (7.5YR 3/2) moist; weak fine granular and subangular blocky structure; very hard, firm; many fine and medium roots; neutral; clear smooth boundary. (3 to 6 inches thick)
Bt1--4 to 17 inches; reddish brown (5YR 5/4) clay, reddish brown (5YR 4/4) moist; moderate medium angular blocky structure; extremely hard, very firm; few fine roots; many thick clay films 1 chroma darker than soil matrix; slightly alkaline; clear smooth boundary. (7 to 15 inches thick)
Btk--17 to 23 inches; reddish brown (5YR 5/4) clay, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; very hard, firm; few fine roots; common thin clay films 1 chroma darker than soil matrix; common very fine and fine concretions of calcium carbonate; few weathered fragments of dolomite mainly less than 3 inches across long axis; strongly effervescent; moderately alkaline; clear smooth boundary. (6 to 26 inches thick)
R--23 to 48 inches; indurated, light gray dolomitic limestone bedrock; coarsely fractured; coatings of calcium carbonate less than 0.3 inch thick on surface of weathered bedrock and in fractures; few fractures penetrated by plant roots; slightly effervescent; moderately alkaline; abrupt smooth boundary. (12 to 33 inches thick)
Cd1--48 to 66 inches; olive gray (5Y 5/2) weakly consolidated shale, olive gray (5Y 4/2) moist; massive; rock structure with many fractures; few streaks of weak red (10R 4/3); few masses calcium carbonate; moderately alkaline; strongly effervescent; gradual smooth boundary. (14 to 22 inches thick)
Cd2--66 to 80 inches; weak red (10R 4/3) weakly consolidated shale, dusky red (10R 3/3) moist; massive; rock structure with many fractures; few masses calcium carbonate; moderately alkaline; strongly effervescent.
TYPE LOCATION: King County, Texas; From the Courthouse in Guthrie, 15.9 miles east on U. S. Highway 82; 4.1 miles north on ranch entrance road passing old ranch house and onto pipeline-ranch road, and 20 feet west of road in rangeland. Ox Yoke Creek quadrangle; (Latitude 33N 37 32; Longitude 100N 01 11)
RANGE IN CHARACTERISTICS: Solum thickness and an abrupt depth to hard bedrock ranges from 20 to 40 inches. Weighted average clay content of the particle size control section ranges from 35 to 50 percent. Depth to secondary carbonates ranges from 12 to 20 inches. A thin coating of precipitated calcium-magnesium carbonate is on the bedrock.
The A horizon has hue of 5YR to 10YR, value of 4 or 5, and chroma of 2 to 4. Reaction is neutral or slightly alkaline.
The Bt1 horizon has hue of 2.5YR or 5YR, value of 4 or 5, and chroma of 4 to 6. Clay films are 1 chroma darker than soil matrix. Reaction ranges from neutral to moderately alkaline and is noneffervescent to slightly effervescent.
The Btk horizon has hue of 2.5YR or 5YR, value of 4 or 5, and chroma 4 to 6. Texture is clay or clay loam. Clay films are 1 chroma darker than soil matrix. Reaction is mostly strongly effervescent and moderately alkaline, but a few pedons are noneffervescent and slightly alkaline. Concretions and masses of calcium carbonate make up as much as 5 percent by volume in most pedons. Fragments of weathered dolomitic limestone mainly less than 3 inches across long axis comprise as much as 5 percent of the volume of some horizons.
The R layer is indurated and coarsely fractured dolomitic limestone about 1 to 3 or more feet thick. The surface of the limestone is weathered and commonly is capped with a coating of precipitated calcium-magnesium carbonate less than 1 cm thick. Some fractures are sealed by the calcium-magnesium carbonate.
The Cd1 and Cd2 layers are stratified weakly consolidated shales. The first shale bed below the dolomitic limestone is grayish. The next lower shale bed has reddish colors. The shales are moderately alkaline and strongly effervescent.
COMPETING SERIES: These are the Acove, Bluegrove, Callahan, Katemcy, and Lindale series in the same family and the similar Bexar, Bronte, Lindy, Rowden, Scullin, and Swenson series. Acove soils have stony argillic horizons over weakly consolidated sandstone. Bluegrove soils are underlain by weathered sandstone. Callahan soils are underlain by shaly clays. Katemcy soils are underlain by schist. Bexar, Rowden, Scullin, and Swenson soils have mollic epipedons. Bronte soils have sola more than 40 inches thick and are underlain by loamy material. Lindale soils are underlain by gravelly clay. Lindy soils lack argillic horizons with accumulations of calcium carbonate and occur in areas of higher rainfall.
GEOGRAPHIC SETTING: Foursixes soils are on upland limestone ridges and mesas. The underlying Permian dolomitic limestone is generally of the Blaine Formation of Permian age. Slope gradients are 0 to 1 percent. The climate in the area of occurrence is dry subhumid with a mean annual precipitation range of 22 to 24 inches. Mean annual temperature ranges from 62 to 64 degrees F. Frost-free season ranges from 210 to 230 days and elevation ranges from 1600 to 1850 feet. Thornthwaite P-E indices range from 34 to 38.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Cottonwood, Knoco, Talpa, Tilvern, Vernon, and Westill soils. Cottonwood soils are underlain by gypsum. Knoco, Tilvern, Vernon and Westill soils are underlain by reddish clays and shale with clay texture. Talpa soils have loamy control sections and are underlain by limestone at depths of less than 20 inches.
DRAINAGE AND PERMEABILITY: The soil is well drained. Permeability is moderately slow. Runoff is low.
USE AND VEGETATION: These soils are used as rangeland. Native vegetation includes buffalograss, sideoats grama, silver bluestem, hairy grama, tobosa grass, Texas wintergrass, slim tridens, skunkbush sumac, silverleaf nightshade, pricklypear cactus, mesquite, redberry juniper and hackberry.
DISTRIBUTION AND EXTENT: North Central Texas in the western part of the Rolling Plains (MLRA 78B). The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: King County, Texas; 1999.
REMARKS: This series includes some soils formerly correlated as a moderately deep variant of the Hensley series.
This soil is in the (Superactive) cation exchange activity class based on Amendment 18 to SOIL TAXONOMY.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 4 inches (A horizon)
Argillic horizon - 4 to 23 inches. (Bt and Btk horizons)
Lithic contact feature - 23 to 27 inches. (R layer)
ADDITIONAL DATA:
Soil Interpretation Record Number: TX1365