Established Series


The Selden series consists of very deep, moderately well drained moderately slow permeable soils that formed in loamy materials. These upland soils have slopes ranging from 1 to 8 percent.

TAXONOMIC CLASS: Fine-loamy, siliceous, active, thermic Aquic Paleustalfs

TYPICAL PEDON: Selden fine sand--cropland. (Colors are for dry soil unless otherwise stated.)

Ap--0 to 6 inches; pale brown (10YR 6/3) fine sand, brown (10YR 5/3) moist; single grained; loose, very friable; slightly acid; clear smooth boundary. (2 to 8 inches thick)

E--6 to 10 inches; very pale brown (10YR 8/3) fine sand, pale brown (10YR 6/3) moist; single grained; loose; slightly acid; clear wavy boundary. (2 to 12 inches thick)

Bt1--10 to 24 inches; brownish yellow (10YR 6/6) sandy clay loam, yellowish brown (10YR 5/6) moist; many fine to medium prominent light brownish gray (10YR 6/2) and red (2.5YR 4/8) mottles; weak fine subangular blocky structure; very hard; nearly continuous clay films; slightly acid; gradual wavy boundary. (6 to 18 inches thick)

Bt2--24 to 36 inches; coarsely mottled, yellow (10YR 7/6), light gray (10YR 7/1), and red (2.5YR 5/8) sandy clay loam; weak medium blocky structure; very hard; patchy clay films; medium acid; gradual wavy boundary. (8 to 24 inches thick)

Bt3--36 to 48 inches; light gray (10YR 7/1) sandy clay loam, gray (10YR 6/1) moist; common medium and coarse prominent yellow (10YR 7/6) and red (2.5YR 4/8) mottles; weak coarse blocky structure; very hard, firm; patchy clay films; medium acid; gradual wavy boundary. (8 to 16 inches thick)

Bt4--48 to 80 inches; light gray (10YR 7/1) sandy clay loam, gray (10YR 6/1) moist; common medium and coarse distinct yellow (10YR 7/6) and few fine prominent red mottles; weak coarse blocky structure; very hard, firm; patchy clay films; medium acid.

TYPE LOCATION: Erath County, Texas; from the Erath County Courthouse in Stephenville, north 1.4 miles on Texas Highway 108 to junction of Farm Road 2808; 3.6 miles west on Farm Road 2808; 150 feet north of road right-of-way in a cultivated field.

RANGE IN CHARACTERISTICS: Solum thickness ranges from 60 to more than 80 inches. Clay content of the control section ranges from 20 to 35 percent. Siliceous or ironstone pebbles range from none to few throughout.

The A or Ap horizon has colors in hue of 7.5YR to 10YR, value of 4 to 6, chroma 2 to 4. The E horizon has value or chroma 1 to 2 units greater than the A horizons. Texture of the A and E horizons is fine sand or loamy fine sand. The reaction ranges from medium acid to neutral.

The Bt1 horizon has colors with hue of 7.5YR or 10YR, value of 5 or 6, chroma of 4 to 8 with or without grayish or reddish mottles. Lower Bt horizons are mottled in shades of yellow, brown, red, and gray or they have gray matrix with reddish, yellowish, or brownish mottles. Wetness mottles with chroma of 2 or less are at a depth of 10 to 30 inches. The texture is sandy clay loam or clay loam. Reaction ranges from strongly acid to slightly acid.

COMPETING SERIES: There are no other series in this family. Soils in closely similar families include Demona, Duffau, Nimrod, and Rader series. Demona soils have clayey control sections. Duffau soils have brown Bt horizons that lack wetness mottles. Nimrod soils have a sandy epipedon 20 to 40 inches thick. Rader soils have a clayey lower Bt horizon.

GEOGRAPHIC SETTING: Selden soils are on uplands with mixed concave and convex surfaces. Slope gradients are dominantly 1 to 5 percent, but range from 1 to 8 percent. The soils formed in sandy clay loams and sandy loams mainly of Lower Cretaceous age. The average annual precipitation ranges from 24 to 34 inches; the mean annual temperature ranges from 63 to 68 degrees F.; and the Thornthwaite P-E index ranges from 44 to 54. Frost free period is 230 to 240 days and elevation ranges from 400 to 1100 feet.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Demona, Duffau, and Nimrod soils and the Chaney, Patilo, and Windthorst series. Chaney soils have a clayey control section and along with Demona and Nimrod soils are on similar or slightly lower positions. Windthorst soils have a red clayey Bt horizon and along with Patilo soils that have sandy epipedon 40 to 60 inches thick are above on higher positions.

DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; moderately slow internal drainage; moderately slow permeability.

USE AND VEGETATION: Most of these soils were cleared and cultivated at one time. Some areas are still farmed to peanuts, sorghums, and vegetable crops. Many areas are being used for tame pastures. Native vegetation is post oak and blackjack oak trees, with a heavy understory of greenbriers, little bluestem, and purpletop tridens.

DISTRIBUTION AND EXTENT: Mainly in the sandy timbered areas in north-central Texas. The soil is of moderate extent.


SERIES ESTABLISHED: Parker County, Texas; 1973.

REMARKS: These soils were previously mapped as thin surface phases of the Nimrod series.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - from 0 to 10 inches.

Albic horizon - 6 to 10 inches.

Argillic horizon - from 10 to 80 inches.

Aquic features - gray mottles of chroma 2 or less within 30 inches of surface.

ADDITIONAL DATA: SDHPT data from Baylor County, Texas (S70TX-012-006).

National Cooperative Soil Survey