LOCATION FRIOTON OK+TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Cumulic Hapludolls
TYPICAL PEDON: Frioton silty clay loam--pasture. (Colors are for moist soil unless otherwise stated.)
A11--0 to 24 inches; very dark brown (10YR 2/2) silty clay loam, very dark gray (10YR 3/1) dry; strong fine granularstructure; hard, friable; 10 percent by volume of fragments of limestone less than 3 inches in diameter in the lower part; calcareous, moderately alkaline; diffuse smooth boundary. (12 to 28 inches thick)
A12--24 to 37 inches; very dark gray (10YR 3/1) silty clay loam, dark gray (10YR 4/1) dry; moderate medium subangular blocky structure; hard, firm; 2 percent by volume of fragments of limestone less than 3 inches in diameter; few fine threads of carbonate; calcareous, moderately alkaline; gradual smooth boundary. (10 to 30 inches thick)
C--37 to 62 inches; very dark gray (10YR 3/1) silty clay loam, dark gray (10YR 4/1) dry; massive; hard, firm; 10 percent by volume of fragments of limestone less than 3 inches in diameter; calcareous, moderately alkaline.
TYPE LOCATION: Bryan County, Oklahoma; about 3 miles southwest of Caddo; 360 feet east and 820 feet south of the northwest corner of sec. 24, T. 5 S., R. 9 E.
RANGE IN CHARACTERISTICS: Thickness of the mollic epipedon ranges from 24 to more than 50 inches. Texture throughout the soil is silty clay loam, clay loam, silty clay, or their gravelly counterparts.
The A horizon is black (10YR 2/1), very dark brown (10YR 2/2), very dark gray (10YR 3/1), very dark grayish brown (10YR 3/2), or dark brown (10YR 3/3; 7.5YR 3/2). Reaction is slightly or moderately alkaline. Some pedons are noncalcareous in the upper
10 inches of the A11 horizon. The clay content of the control section ranges from 35 to 50 percent. The control section of some pedons contains 5 to 15 percent by volume of fragments of limestone or chert. Below a depth of 24 inches, some pedons have B horizons that have higher value or chroma than the A horizons.
The C horizon is very dark gray (10YR 3/1), very dark grayish brown (10YR 3/2), dark brown (10YR 3/3; 7.5YR 3/2), dark gray (10YR 4/1), dark grayish brown (10YR 4/2), brown (10YR 4/3, 5/3; 7.5YR 4/2, 5/2), or gray (10YR 5/1). Some pedons have thin strata of more loamy or clayey sediments in the C horizon.
COMPETING SERIES: These are the Egan series and the closely competing Buxin, Catalpa, Moreland, Pledger, and Ringo series. Buxin, Moreland, and Pledger soils have vertic properties. Catalpa and Ringo soils have mollic epipedons less than 24 inches thick. In addition, Ringo soils are underlain by shale at depths ranging from 20 to 40 inches. Egan soils lack carbonates within the profile.
GEOGRAPHIC SETTING: These soils occur on nearly level flood plains. Slopes range from 0 to 1 percent. They formed in loamy and clayey sediments. They are flooded for very brief periods during the months of February through July. Mean annual temperature ranges from 62 degrees to 70 degrees F.; average annual precipitation ranges from 40 to 50 inches; Thornthwaite P-E indices range from 64 to 80. Frost free days range from 210 to 240. Elevation ranges from 400 to 800 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gowton, Kaufman, and Trinity series. Gowton and Kaufman soils are down stream and usually on larger streams. Trinity soils are a greater distance from the stream channel. Gowton soils are fine-loamy. Kaufman and Trinity soils have vertic properties.
DRAINAGE AND PERMEABILITY: Well drained; low runoff; moderately slow permeability.
USE AND VEGETATION: Used primarily for bermudagrass pasture but some areas are cultivated to wheat, grain sorghum, soybeans, peanuts, and alfalfa. Native vegetation is oak, elm, hackberry, pecan, and ash with an understory of native grass.
DISTRIBUTION AND EXTENT: Adjacent to the drainageways of the Blacklands in southeastern Oklahoma, possibly Texas, southwestern Arkansas, and Louisiana. These soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Bryan County, Oklahoma; 1975.
REMARKS: This series formerly would have been classified in the Alluvial great soil group and included in the Frio series.