LOCATION COX                     ID

Established Series
Rev. MEJ/CLM
11/2010

COX SERIES

The Cox series consists of shallow, well drained soils that formed in aeolian material reworked by water. Cox soils are on basalt plains and have slopes of 2 to 15 percent. Permeability is moderately rapid. The annual precipitation is about 11 inches, and the annual air temperature is about 47 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Aridic Lithic Haploxerolls

TYPICAL PEDON: Cox very stony sandy loam - on a 2 percent slope at an elevation of 4,790 feet in rangeland. When described on September 24, 1980, the profile was moist to 12 inches. (Colors are for dry soil unless otherwise noted.)

A1--0 to 4 inches; brown (10YR 4/3) very stony sandy loam, dark brown (10YR 3/3) moist; weak fine granular structure; loose, very friable; many very fine, fine, and medium roots; many very fine and fine interstitial pores; about 5 percent gravel, 30 percent cobbles, and 15 percent stones; slightly acid (pH 6.2); clear smooth boundary. (3 to 8 inches thick)

A2--4 to 9 inches; brown (10YR 4/3) very stony sandy loam, dark brown (10YR 3/3) moist; weak fine and medium granular structure; soft and very friable; many very fine, fine, and medium roots; many very fine and fine interstitial pores; about 5 percent gravel, 20 percent cobbles, and 30 percent stones; slightly acid (pH 6.2); clear wavy boundary. (0 to 8 inches thick)

Bw--9 to 12 inches; dark yellowish brown (10YR 4/4) very stony sandy loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, slightly sticky; common very fine and fine roots; common very fine and fine interstitial pores; about 5 percent gravel, 20 percent cobbles, and 30 percent stones; slightly acid (pH 6.5); abrupt smooth boundary. (5 to 7 inches thick)

2R--12 inches; fractured basalt bedrock.

TYPE LOCATION: Lincoln County, Idaho about 14 miles east and 6 miles north of Richfield; 3,000 feet east and 2,800 feet north of the southwest corner, sec. 29, T. 3 S., R. 22 E.

RANGE IN CHARACTERISTICS:

Depth to basalt bedrock - 10 to 20 inches
Annual soil temperature - 47 to 52 degrees F.
Thickness of mollic epipedon - 8 to 12 inches
Base saturation - less than 75 percent in some part above the lithic contact

A horizon
Value - 4 or 5 dry
Chroma - 2 or 3 moist or dry

Bw horizon
Value - 4 or 5 dry, 3 or 4 moist
Chroma, moist or dry - 3 or 4
Texture - CBV-FSL, STV-SL, STX-SL
Clay content - 8 to 15 percent
Rock fragments - 35 to 60 percent
Reaction - slightly acid to mildly alkaline

COMPETING SERIES: These are the Brisky, Rufus, Swakane, Teamont and Witzel series. Brisky, Rufus, Swakane, and Teamont soils have a xeric moisture regime. Witzel soils have hues of 7.5YR or redder and are medium and moderately fine textured in the fine earth fraction.

GEOGRAPHIC SETTING: Cox soils are on basalt plains. Slopes range from 2 to 15 percent. Elevation ranges from 4,300 to 5,000 feet. The soil formed in aeolian material reworked by water over basalt bedrock. The climate is semi-arid with annual precipitation of 10 to 13 inches, most of which falls as snow and early spring rain. The annual air temperature is about 45 to 50 degrees F. The frost-free season is 85 to 125 days.

GEOGRAPHICALLY ASSOCIATED SOILS: They are the Deerhorn, Rehfield, and Wildors soils. Deerhorn and Wildors soils are moderately deep to a duripan. Rehfield soils are very deep and have argillic horizons. Deerhorn and Wildors soils occur on the same landscape position. Rehfield soils occur in drainageways and in depressions.

DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow to medium. Permeability is moderately rapid.

USE AND VEGETATION: Mainly used for rangeland. Vegetation is basin big sagebrush, bluebunch wheatgrass, rabbitbrush, Nevada bluegrass, and arrowleaf balsamroot.

DISTRIBUTION AND EXTENT: South-central Idaho. The series is moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Blaine County, Idaho, 1985.

REMARKS: Diagnostic horizons and features recognized in this series are:

Mollic epipedon - the zone from the surface of the soil to approximately 12 inches

Lithic contact - about 12 inches

Ultic subgroup criteria is also met

Aridic moisture regime - dry more than half of the time

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National Cooperative Soil Survey
U.S.A.