LOCATION FRANKIRK TX+OKEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Typic Argiustolls
TYPICAL PEDON: Frankirk clay loam - cultivated. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 7 inches; reddish brown (5YR 5/3) clay loam, dark reddish brown (5YR 3/3) moist; weak fine granular structure; slightly hard, friable; neutral; abrupt smooth boundary. (5 to 9 inches thick)
Bt1--7 to 16 inches; reddish brown (5YR 4/3) clay loam, dark reddish brown (2.5YR 3/3) moist; weak coarse prismatic structure parting to moderate medium angular blocky; hard, firm; nearly continuous clay films; slightly alkaline; gradual smooth boundary. (5 to 11 inches thick)
Bt2--16 to 35 inches; reddish brown (2.5YR 4/4) clay, dark reddish brown (2.5YR 3/4) moist; weak coarse prismatic structure parting to moderate medium angular blocky; hard, firm; nearly continuous clay films; slightly alkaline; gradual smooth boundary. (15 to 24 inches thick)
Bt3--35 to 48 inches; red (2.5YR 5/6) clay loam, red (2.5YR 4/6) moist; moderate medium subangular blocky structure; hard, friable; nearly continuous clay films; slightly effervescent; moderately alkaline; diffuse smooth boundary. (8 to 20 inches thick)
Btk--48 to 64 inches; yellowish red (5YR 5/6) sandy clay loam, yellowish red (5YR 4/6) moist; moderate medium subangular blocky structure; hard, friable; clay films on some peds; contains about 2 percent by volume of calcium carbonate concretions; strongly effervescent; moderately alkaline; gradual smooth boundary. (0 to 18 inches thick)
Bk--64 to 85 inches; reddish yellow (5YR 6/6) sandy clay loam, yellowish red (5YR 5/6) moist; weak fine granular structure; hard, friable; contains 5 percent by volume of calcium carbonate concretions; strongly effervescent; moderately alkaline; diffuse smooth boundary. (12 to 25 inches thick)
C--85 to 100 inches; yellowish red (5YR 5/6) loam, yellowish red (5YR 4/6) moist; massive; hard, friable; strongly effervescent; moderately alkaline.
TYPE LOCATION: Stonewall County, Texas from the intersection of U.S. Highway 380 and Farm Road 1835 0.1 mile north of the Post Office in Old Glory, 2.6 miles east on a county road, 100 feet north in a cultivated field.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80 inches. The mollic epipedon is 11 to 18 inches thick, Depth to secondary carbonates range from 29 to 48 inches. Gravels less than 2 inches across the long axis range from 0 to 3 percent in the control section.
The A horizon has hue of 5YR or 7.5YR, value of 3 to 5, and chroma of 2 or 3. Texture is loam, sandy clay loam or clay loam. Reaction is neutral or slightly alkaline.
The Bt1 horizon has hue of 2.5YR to 7.5YR, value of 4 or 5, and chroma of 2 or 3. Texture is sandy clay loam, clay loam, silty clay loam or clay. Reaction ranges from neutral to moderately alkaline.
The Bt2 and Bt3 horizons have hue of 2.5YR or 5YR, value of 4 or 5, and chroma of 4 through 6. They are clay loam, sandy clay, silty clay loam or clay with clay content of 35 to 45 percent. Reaction ranges from neutral to moderately alkaline. Calcium Carbonate Equivalent ranges from 0 to 5 percent.
The Btk and Bk horizons have hue of 2.5YR or 5YR, value of 4 through 6, and chroma that is dominantly 6. They are loam, sandy clay loam, silty clay loam or clay loam with 20 to 30 percent clay. Calcium carbonate concretions range from 2 percent in the upper part to 20 percent in the lower part. Calcium Carbonate Equivalent ranges from 5 to 15 percent. Gravel ranges from 0 to 10 percent.
The C horizon is loam, clay loam, or sandy clay loam with 20 to 30 percent clay. Calcium Carbonate Equivalent ranges from 2 to 10 percent. Gravel ranges from 0 to 10 percent.
COMPETING SERIES: These are the Bexar, Lawton, Luckenbach, Rowden, Sagerton and Swenson soils in the same family. Bexar, Rowden, and Swenson soils are 20 to 40 inches deep to bedrock. Lawton soils do not have secondary carbonates within 48 inches, and formed from granitic outwash. Luckenbach soils have secondary carbonates within a depth of 28 inches. Sagerton soils have calcic horizons at less than 60 inch depths. In addition, Sagerton soils have carbonates at less than 28 inches.
GEOGRAPHIC SETTING: Frankirk soils are on nearly level to gently sloping plains. Slopes range from 0 to 5 percent. The soils formed in loamy calcareous sediments that are considered ancient alluvium on terrace pediments. The climate is dry subhumid, Thornthwaite annual P-E indices are 31 to 44 and the average annual precipitation is 21 to 27 inches. Mean annual temperature ranges from 57 to 65 degrees F. Frost free days range from 185 to 230. Elevation ranges from 1000 to 2200 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Abilene series and the Aspermont, Bukreek Grandfield and Miles series. Aspermont soils do not have a mollic epipedon or a argillic horizon and are on higher landscape positions. Bukreek, Grandfield, and Miles soils have less than 35 percent clay in the argillic horizon and are on similiar landscape positions.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability; runoff is low on slopes of less than 1 percent, medium on 1 to 5 percent slopes.
USE AND VEGETATION: Most areas are cultivated. Wheat, cotton, and grain sorghum are the principle crops. Native grasses are mainly buffalograss, blue grama, sideoats grama and silver bluestem.
DISTRIBUTION AND EXTENT: Central Rolling Red Plains (MLRA 78B, 78C) of Texas and Oklahoma. The soil is moderately extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Stonewall County, Texas; 1970.
REMARKS: The Frankirk soils were formerly included in the Olton and Wichita series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 16 inches.
Argillic horizon - the Bt horizons, from 16 to 48 inches.
Calcic horizon - the zone from 64 to 85 inches.
Soil Interpretation Record: TX0617