LOCATION BOLAR TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, carbonatic, thermic Udic
Calciustolls
TYPICAL PEDON: Bolar clay loam--cultivated. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 6 inches; brown (10YR 4/3) clay loam; dark brown (10YR 3/3) moist; weak fine subangular blocky and granular structure; hard, friable; few fine strongly cemented calcium carbonate concretions; moderately alkaline; calcareous; abrupt smooth boundary. (4 to 8 inches thick)
A--6 to 16 inches; dark brown (10YR 3/3) clay loam, very dark brown (10YR 2/2) moist; moderate fine subangular blocky and granular structure; hard, friable; few strongly cemented calcium carbonate concretions; moderately alkaline; calcareous; clear smooth boundary. (3 to 12 inches thick)
Bk1--16 to 28 inches; pale brown (10YR 6/3) clay loam, brown (10YR 5/3) moist; moderate fine subangular blocky and granular structure; hard, firm; common fine strongly cemented concretions and few threads and films of calcium carbonate; moderately alkaline; calcareous; gradual smooth boundary. (8 to 15 inches thick)
Bk2--28 to 32 inches; very pale brown (10YR 7/3) clay loam, pale brown (10YR 6/3) moist; moderate fine subangular blocky and granular structure; hard, firm; common fine strongly cemented concretions and common films and threads of calcium carbonate; few fragments of limestone less than 3 inches across; moderately alkaline; calcareous; clear smooth boundary. (0 to 8 inches thick)
Bk3--32 to 36 inches; interbedded yellowish brown (10YR 5/4) clay loam and limestone; weak fine subangular blocky structure; 30 percent by volume of limestone fragments up to 5 inches across the long axis; common soft masses, films and threads of calcium carbonate; moderately alkaline; calcareous; abrupt smooth boundary. (0 to 7 inches thick)
R--36 to 44 inches; indurated limestone bedrock, that is fractured and interbedded with calcareous marly clay.
TYPE LOCATION: Erath County, Texas; from the intersection of Loop 195 and Farm Road 914, in the south part of Stephenville, Texas; 5.6 miles south on Farm Road 914, then 80 yards east of the road in the north edge of a cultivated field.
RANGE IN CHARACTERISTICS: The solum ranges from 20 to 40 inches thick. The silicate clay content of the control section ranges from 20 to 35 percent. Fragments of limestone and indurated carbonate concretions range from pebble to stone size, but are mainly less than 18 inches across and range from a few to 35 percent by volume. Some thin lower layers contain up to 50 percent by volume of limestone fragments. The fragments are throughout the pedon or exist in discontinuous stone lines or as remnants of a petrocalcic horizon. The calcium carbonate equivalent ranges from 40 to 75 percent in the control section.
The A horizon has colors with hue of 7.5YR or 10YR, value of 2 to 5, and chroma of 2 or 3. They are loam, clay loam, silty clay loam, or their gravelly counterparts.
The Bk horizons have colors with hue of 7.5YR, 10YR, or 2.5Y, value of 4 to 7, chroma of 2 to 6. Texture is loam, clay loam, or silty clay loam, or their gravelly counterparts.
The R layer is indurated fractured limestone interbedded with chalky limestone, marl, or marly clay at vertical intervals of 6 to about 12 inches.
COMPETING SERIES: These include Carbengle, Rumley, Sunev, and Topsey series in the same family and the similar Austin, Clarke, Denton, Doss, Engle, Nuvalde, Purves, Quanah, Somervell, and Venus series. Carbengle, Rumley, Sunev, and Topsey soils lack a lithic contact within 40 inches. Austin and Quanah soils have less than 15 percent coarser than very fine sand in the 10- to 40-inch control section. Clarke, Engle, Nuvalde, and Venus soils have less than 40 percent carbonates in the 10- to 40-inch control section. In addition, Nuvalde soils have more than 35 percent average clay content in the Bt horizon. Denton soils are more clayey in the upper part. Doss soils have a paralithic contact with limestone at depths of 11 to 20 inches. Purves soils are more clayey and have a lithic contact with limestone at depths of 8 to 20 inches. Somervell soils contain more than 35 percent coarse fragments in the 10- to 40-inch control section.
GEOGRAPHIC SETTING: Bolar soils are on gently sloping to moderately steep uplands. Slope gradients are predominantly 1 to 5 percent, but range to 15 percent. The soil formed in interbedded limestones and calcareous marls of cretaceous age mainly in the Georgetown, Denton clay, Fort Worth limestone, Duck Creek limestone, and Kiamichi clay formations. The mean annual precipitation ranges from 28 to 36 inches, Thornthwaite annual P-E indices are about 44 to 56, and mean annual temperature is about 64 to 68 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Denton, Purves, Somervell, and Venus series, as well as Brackett, Dugout, Karnes, and Tarrant series. Brackett and Dugout soils are shallow soils with light colored surface layers. Karnes soils have a light colored surface layer and a coarse-loamy control section. Tarrant soils are shallow and have a clayey-skeletal control section.
DRAINAGE AND PERMEABILITY: Bolar soils are well drained. Runoff is medium to rapid, and permeability is moderate.
USE AND VEGETATION: Mostly used for pasture or range. Some areas are used for growing small grains, sorghums, cotton, and corn. Native vegetation is dominantly midgrasses, including little bluestem and sideoats grama.
DISTRIBUTION AND EXTENT: In Texas; mostly in the Grand Prairie area of central and north-central Texas. Bolar soils are of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Eastland County, Texas; 1972.
REMARKS: The Bolar series formerly was included in the Denton series.
Classification was changed 11/89 from Typic Calciustolls to Udic Calciustolls.
Diagnostic features and horizons recognized in this pedon are:
Mollic epipedon - 0 to 16 inches
Calcic horizon - 16 to 36 inches
Lithic contact - at 36 inches contact with indurated limestone bedrock