LOCATION OAKLEY OK+TXEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, thermic Typic Calciustolls
TYPICAL PEDON: Oakley loam--on 1 percent slope in cropland. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 7 inches; brown (7.5YR 5/3) loam, dark brown (7.5YR 3/3) moist; moderate fine and medium granular structure; hard, friable; many very fine, fine, and medium roots; few very fine, fine, and medium interstitial and tubular pores; common worm casts; few fine concretions of calcium carbonate; strongly effervescent; slightly alkaline; abrupt smooth boundary.
A--7 to 12 inches; reddish brown (5YR 5/3) loam, reddish brown (5YR 4/3) moist; moderate fine and medium granular structure; hard, friable; common very fine, fine, and medium roots; few very fine, fine, and medium interstitial and tubular pores; common worm casts; few fine masses and common fine and medium concretions of calcium carbonate; strongly effervescent; moderately alkaline; clear smooth boundary. (Combined thickness of the A horizon is 7 to 16 inches)
Bk1--12 to 30 inches; red (2.5YR 5/6) loam, red (2.5YR 4/6) moist; moderate coarse prismatic structure parting to moderate medium subangular blocky; hard, friable; common very fine, fine, and medium roots; common very fine, fine, and medium interstitial and tubular pores; few fine masses of iron-manganese; common medium and coarse masses and common fine and medium concretions of calcium carbonate; violently effervescent; moderately alkaline; gradual wavy boundary.
Bk2--30 to 43 inches; red (2.5YR 5/6) loam, red (2.5YR 4/6) moist; moderate coarse prismatic structure parting to moderate medium subangular blocky; hard, friable; few very fine, fine and medium roots; common very fine, fine, and medium interstitial and tubular pores; few fine masses of iron-manganese; common medium and coarse masses and common fine and medium concretions of calcium carbonate; violently effervescent; strongly alkaline; gradual wavy boundary.
Bk3--43 to 58 inches; red (2.5YR 5/6) loam, red (2.5YR 4/6) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; hard, friable; very few very fine and fine roots; common very fine, fine, and medium interstitial and tubular pores; common fine and medium masses and common medium and coarse concretions of calcium carbonate; few fine and medium distinct light brown (7.5YR 6/4) iron depletions; strongly effervescent; strongly alkaline; clear smooth boundary. (Combined thickness of the Bk horizon is 21 to 60 inches)
BC--58 to 85 inches; red (2.5YR 5/8) sandy clay loam, red (2.5YR 4/8) moist; weak coarse prismatic structure; hard, friable; few fine and medium distinct light brown (7.5YR 6/4) iron depletions; slightly effervescent; moderately alkaline; clear smooth boundary. (0 to 30 inches thick)
C--85 to 95 inches; red (2.5YR 5/8) gravelly sandy loam, red (2.5YR 4/8) moist; weak medium prismatic structure; hard, friable; 20 percent rounded quartzite gravel; few fine and medium distinct light brown (7.5YR 6/4) iron depletions; slightly alkaline; abrupt wavy boundary. (0 to more than 40 inches thick)
2Cd--95 to 100 inches; red (2.5YR 5/6) weathered siltstone with texture of silty clay loam, red (2.5YR 4/6) moist; massive; extremely hard, firm; slightly alkaline.
TYPE LOCATION: Jackson County, Oklahoma; from the intersection of U. S. Highway 62 and 283 in Altus; about 8 miles east on U. S. Highway 62; 4 miles north on paved county road; 0.2 miles west on county road; 450 feet north in cropland. (1100 feet west and 450 feet north of southeast corner of section 28, T.3 N., R.19 W.); USGS Quad: Headrick, OK; Latitude: 34N, 41, 51; Longitude: 99W, 11, 51.
RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 60 to more than 80 inches. Depth to a lithologic discontinuity of weathered Permian age redbed sediments ranges from 60 to more than 80 inches. Some pedons contain a few brown or gray redoximorphic depletions below 40 inches. Most pedons have a perched water table below 48 inches during the winter and spring of years with above normal rainfall. These soils are calcareous throughout.
The A horizon has hue of 5YR to 10YR, value of 4 or 5, and chroma of 2 or 3. Texture is loam or clay loam. Reaction is slightly alkaline or moderately alkaline.
The Bk horizon has hue of 2.5YR to 7.5YR, value of 4 or 5, and chroma of 4 or 6. Texture is loam, sandy clay loam, or clay loam. Reaction is moderately alkaline or strongly alkaline. Calcium carbonate ranges from 3 to 25 percent by volume in the form of concretions, films, or masses. Calcium carbonate equivalent ranges from 10 to 35 percent and a layer at least 6 inches thick contains 15 percent or more. Some pedons contain a few masses of iron-manganese.
The BC horizon has hue of 2.5YR or 5YR, value of 4 or 5, and chroma of 4 to 8. Texture is loam, sandy loam, sandy clay loam, or clay loam. Reaction is moderately alkaline or strongly alkaline. Calcium carbonate ranges from 0 to 5 percent by volume and calcium carbonate equivalent ranges from 3 to 15 percent.
The C horizon, where present, has color similar to the BC horizon. Texture is variable and is commonly stratified with texture ranging from loamy sand to clay loam. Some pedons have gravelly strata containing up to 30 percent coarse fragments. Reaction is moderately alkaline or strongly alkaline.
The 2C or 2Cd horizon has hue of 2.5YR, value of 4 or 5, and chroma of 4 or 6. Texture is silty clay, silty clay loam, or clay and is weathered from Permian age redbed sediments.
COMPETING SERIES: These are the Clark and Engle series in the same family and the similar Berda, Ruella, Quanah, Nuvalde, and Weymouth series. Clark soils formed in brown eolian high plains sediments. Engle soils are moderately deep to sandstone. Berda, Ruella, and Weymouth soils have an ochric epipedon. In addition, Berda soils are in a drier climate, Ruella soils are in a moister climate, and Weymouth soils are moderately deep to Permian age redbed sediments. Quanah and Nuvalde soils have a fine-silty particle-size control section and are associated with soils formed from limestone.
GEOGRAPHIC SETTING: Oakley soils formed in calcareous loamy alluvium over Permian age redbed sediments. They occur on terraces along creeks and streams in the Central Rolling Red Plains (MLRA 78C & B) of southwestern Oklahoma and north Texas. Slope gradients are typically 0 to 5 percent but range to 8 percent. Mean annual precipitation ranges from 20 to 28 inches. Mean annual temperature ranges from 60 to 64 degrees F. Frost free days range from 200 to 230 days. Elevation ranges from 1000 to 2100 feet. The Thornthwaite annual P-E Index ranges from 32 to 44.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Burford, Grandfield, Grandmore, Ozark, Roark, and Tipton series. These soils do not have a calcic horizon. In addition, Burford soils have an ochric epipedon, have a Cr horizon of Permian age redbed sediments within 60 inches, and occur on similar landscape positions. Grandfield and Grandmore soils have an ochric epipedon, an argillic horizon, and occur on higher landscape positions. Ozark soils have an argillic horizon and occur on slightly higher landscape positions. Roark and Tipton soils have an argillic horizon, a mollic epipedon more than 20 inches thick, and occur on slightly higher broad nearly level areas. Also, Roark soils have a fine particle size control section.
DRAINAGE AND PERMEABILITY: Oakley soils are well drained. Permeability is moderate or moderately slow. Runoff is low on 0 to 1 percent slopes, medium on 1 to 5 percent slopes, and high on 5 to 8 percent slopes. Depth to a perched water table ranges from 4 to 8 feet from the surface during the months of October to May during years with above normal rainfall.
USE AND VEGETATION: Mainly used for cropland. Wheat and sorghum are the principal crops. Some areas have been seeded to Old World bluestem or native grass pasture. Native vegetation is a mixed grass prairie, consisting mainly of little bluestem, grama species, and buffalograss.
DISTRIBUTION AND EXTENT: Central Rolling Red Plains LRR H (MLRA 78B & 78C) of southwestern Oklahoma and northwest parts of Texas. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas.
SERIES ESTABLISHED: Jackson County, Oklahoma, 2000.
REMARKS: These soils were formerly included with Abilene, Mansker, and Weymouth series in previous soil surveys.
Diagnostic horizons and features recognized in this pedon are:
mollic epipedon - 0 to 12 inches (Ap & A horizons)
calcic horizon - 12 to 58 inches (Bk horizons)
The assignment of the cation-exchange activity class is inferred from lab data from Jackson County, OK.
Range Site: Limy Prairie - 078CY057OK
ADDITIONAL DATA: NSSL data from type location in Jackson County, OK (S97OK-065-005)
TAXONOMIC VERSION: Soil Taxonomy, Second Edition, 1999.