LOCATION DARSIL             OK

DARSIL SERIES

TAXONOMIC CLASS: Thermic, shallow, coated Ustic Quartzipsamments

TYPICAL PEDON: Darsil loamy fine sand, on 4 percent convex west facing slope, in a postoak-blackjack forest with an understory of native grasses. When described, the soil was moist throughout. (Colors are for dry soil unless otherwise stated.)

A1--0 to 5 inches; brown (7.5YR 5/2) loamy fine sand, dark brown (7.5YR 3/2) moist; weak fine granular structure; soft, very friable; slightly acid; clear smooth boundary. (3 to 9 inches thick)

EC--5 to 17 inches; pink (7.5YR 7/4) fine sand, brown (7.5YR 5/4) moist; weak fine granular structure; soft, very friable; 2 percent by volume of coarse fragments from 2 mm to 76 mm in diameter; neutral; clear wavy boundary. (6 to 15 inches thick)

Cr--17 to 23 inches; red (2.5YR 5/8) weakly cemented fine grained sandstone, red (2.5YR 4/8) moist; moderately acid.

TYPE LOCATION: Cleveland County, Oklahoma, about 6 miles east of U.S. Highway 77 and Alemeda Street intersection in Norman; 700 feet east and 50 feet south of the northwest corner sec. 32, T. 9 N., R. 1 W.

RANGE IN CHARACTERISTICS: Solum thickness and depth to bedrock ranges from 10 to 20 inches. Reaction ranges from strongly acid to slightly alkaline.

The A horizon has hue of 5YR to 10YR, value of 4 to 6, and chroma of 2 to 6.

The EC horizon has hue of 2.5YR to 10YR, value of 4 to 7, and chroma of 2 to 6. Texture is loamy fine sand or fine sand and contains from 0 to 20 percent by volume of sandstone fragments from 2 mm to 76 mm diameter.

The Cr horizon has hue of 2.5YR or 5YR, value of 3 to 6, and chroma of 4 to 8. It is weakly cemented fine grained sandstone. This material has high or very high excavation difficulty. Fractures are greater than 10 cm apart. Bulk density is high enough to be root restrictive. This material slakes in water within 15 hours.

COMPETING SERIES: These are no other series in this family.

GEOGRAPHIC SETTING: Darsil soils are on very gently sloping to sloping upland convex ridge crests and side slopes of the Cross Timbers (MLRA-84A). Slopes range from 1 to 45 percent. They formed in material weathered from sandstone of Permian age. Mean Annual Precipitation: 30 to 38 inches. Mean Annual Temperature: 58 to 62 degrees F. Thornthwaite Annual P-E indices: 48 to 64. Frost free days range from 200 to 230. Elevation ranges from 750 to 1300 feet.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Darnell, Harrah, Littleaxe, Newalla, and Stephenville series. Darnell soils have a loamy textural control section and occur on the same landscape as Darsil. Harrah soils have a fine-loamy control section, have argillic horizons, have sola more than 60 inches thick, and occur on foot slopes. Littleaxe soils have a fine-loamy control section, an argillic horizon, and a solum 40 to 60 inches thick. Newalla soils have a fine control section, an argillic horizon, and a solum 35 to 60 inches thick. Stephenville soils have a fine-loamy control section, an argillic horizon, and a solum 20 to 40 inches thick.

DRAINAGE AND PERMEABILITY: Darsil soils are excessively drained. Runoff is medium on 1 to 5 percent slopes, high on 5 to 20 percent slopes, and very high on >20 percent slopes, and permeability is rapid.

USE AND VEGETATION: Used mainly as rangeland for beef cattle. The native vegetation is postoak and blackjack oak with an understory of mid and tall grasses.

DISTRIBUTION AND EXTENT: Cross Timbers of central Oklahoma. The series is of moderate extent.

MLRA OFFICE RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Cleveland County, Oklahoma; 1983.

REMARKS: These soils would be classified as Ustic Quartzipsamments if that subgroup were recognized in Taxonomy. Typic Quartzipsamments implies a udic moisture regime and these soils have a ustic regime. Also, these soils are in a coated family.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon- the zone from the soil surface to a depth of 17 inches. (the A & EC horizons)

Paralithic contact- the occurance of paralithic material at 17 inches. (the Cr horizon)

Soil Interpretation Record: OK0238 Darsil Series

ADDITIONAL DATA: Laboratory data is available from Oklahoma State University, Stillwater, Oklahoma. Sample No. 76-OK-14-23.