LOCATION DARNELL OK+KS TXEstablished Series
TAXONOMIC CLASS: Loamy, siliceous, active, thermic, shallow Udic Haplustepts
TYPICAL PEDON: Darnell fine sandy loam--scrub oak forest. (Colors are for dry soil unless otherwise stated.)
A--0 to 5 inches; brown (10YR 5/3) fine sandy loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, very friable; many roots; moderately acid; gradual smooth boundary. (4 to 10 inches thick)
Bw--5 to 15 inches; light brown (7.5YR 6/4) fine sandy loam, dark brown (7.5YR 4/4) moist; weak fine granular structure; slightly hard, very friable; many roots; few fragments of sandstone less than 1 inch in diameter; moderately acid; gradual wavy boundary. (4 to 12 inches thick)
Cr--15 to 30 inches; red (2.5YR 4/6) sandstone, dark red (2.5YR 3/6) moist; difficult to auger; moderately acid.
TYPE LOCATION: Lincoln County, Oklahoma; about 8 miles west of Tryon; 900 feet west and 100 feet north of the southeast corner of sec. 17 T. 16 N., R. 2 E.
RANGE IN CHARACTERISTICS: Solum thickness and depth to sandstone bedrock ranges from 10 to 20 inches.
The A horizon has hue of 5YR to 10YR, value of 4 to 6, and chroma of 2 through 4. Texture is fine sandy loam, sandy loam, loam, stony fine sandy loam, or stony loam. Content of coarse fragments ranges from 0 to 20 percent by volume. Coarse fragments less than 3 inches in diameter range from 0 to 5 percent by volume and coarse fragments 3 to 10 inches in diameter range from 0 to 15 percent by volume. Reaction ranges from strongly acid to neutral.
The Bw horizon has hue of 2.5YR to 10YR, value of 4 to 8, and chroma of 2 to 6. Texture is fine sandy loam, sandy loam, gravelly loam, or gravelly fine sandy loam. Content of coarse fragments ranges from 0 to 20 percent by volume. Coarse fragments less than 3 inches in diameter range from 0 to 20 percent by volume and coarse fragments 3 to 10 inches in diameter range from 0 to 5 percent by volume. Reaction ranges from strongly acid to neutral.
The Cr horizon is weakly to strongly cemented sandstone that can be cut with a spade or auger. The Cr horizon has hue of 10R to 10YR, value of 4 to 7, and chroma of 3 to 8. Reaction ranges from strongly acid to neutral. This material is paralithic with a high or very higy excavation difficulty. Some strata may be lithic with an extremely high excavation difficulty, but these areas are small. Fractures are greater than 10 cm apart. This material is dense enough to be root restrictive. Most of this material slakes in water within 15 hours.
COMPETING SERIES: There are no other series in the same family. Soils in similar families are Darsil, Lucien, and Noble series. Darsil soils have a sandy textural control section. Lucien soils have mixed mineralogy and have a mollic epipedon. Noble soils have a solum more than 20 inches thick.
GEOGRAPHIC SETTING: Darnell soils are on very gently sloping to steep ridge crests and upper side slopes of uplands in the Cross Timbers. Slopes are 1 to 45 percent. These soils formed in sandstone of Permian age. The climate is subhumid.
Mean Annual Precipitation: 28 to 40 inches.
Mean Annual Temperature: 58 to 64 degrees F.
Thornthwaite Annual P-E indices: 44 to 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Darsil, and Noble series and the Harrah, Littleaxe, Newalla, Niotaze, and Stephenville series. Darsil soils occur intermingled in the same landscape, and have a textural control of loamy fine sand or coarser. Harrah, Littleaxe, and Stephenville soils occur on broad flats or side slopes and have Bt horizons. In addition, Harrah soils have a solum more than 60 inches thick, Littleaxe soils have a solum from 40 to 60 inches thick, and Stephenville soils have a solum from 20 to 40 inches thick. Newalla and Niotaze soils occur on broad flats or upper side slopes, have Bt horizons, and have a fine control section. In addition, Newalla and Niotaze soils have a solum more than 20 inches thick.
DRAINAGE AND PERMEABILITY: Well drained or somewhat excessively drained; medium or rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Mainly used for rangeland. Native vegetation is mainly post oak, blackjack oak, and eastern redcedar with an understory of tall and mid grasses.
DISTRIBUTION AND EXTENT: Cross Timbers of Oklahoma, Kansas, and Texas. The series is extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Okfuskee County, Oklahoma; 1942.
ADDITIONAL DATA: Oklahoma State University Lab No. 73-OK-57-20.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface of the soil to a depth of 5 inches (A horizon).
Cambic horizon - the zone from 5 inches to a depth of 15 inches (B horizon).
Paralithic contact - paralithic material at 15 inches.