LOCATION COPPERWORLD             CA

Established Series
Rev: JG/CAH
04/2015

COPPERWORLD SERIES

The Copperworld series consists of very shallow or shallow to bedrock, somewhat excessively drained soils that formed in residuum and colluvium from metamorphic rocks. Copperworld soils are on mountains. Slopes range from 30 to 60 percent. The mean annual precipitation is about 175 mm and the mean annual temperature is about 15 degrees C. The frost-free season is 210 to 270 days/

TAXONOMIC CLASS: Loamy, mixed, superactive, thermic Lithic Haplargids

TYPICAL PEDON: Copperworld gravelly sandy loam, on a N facing 52 percent slope under a cover of shrubby rangeland at an elevation of 1360 m. When described the soil was moist throughout. (Colors are for moist soil unless otherwise noted). The soil surface is partially covered with 15 percent fine gravel, 55 percent medium and coarse gravel, 10 percent cobbles, 3 percent stones and 3 percent boulders.

A--0 to 3 cm, (0 to 1 inches); gravelly sandy loam, dark yellowish brown (10YR 3/4) moist; weak medium platy structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots throughout; common very fine irregular pores; very slightly effervescent; 15 percent gravel, 2 percent cobbles, and 1 percent stones; neutral, pH 7.2 by Phenol red; diffuse smooth boundary. (2 to 4 centimeters thick)

Bt--3 to 15 cm, (1 to 6 inches); gravelly sandy loam, dark brown (10YR 3/3) moist; massive parting to weak fine subangular blocky; soft, very friable, nonsticky and nonplastic; common very fine, fine, and medium roots throughout; common very fine irregular pores; 3 percent distinct brown (7.5YR 5/4), dry, clay films on rock fragments; 15 percent gravel, 4 percent cobbles, and 1 percent stones; slightly alkaline, pH 7.4 by Phenol red; abrupt irregular boundary. (9 to 33 centimeters thick)

R--15 cm, (6 inches); Indurated metamorphic bedrock with roots in fractures greater than 10 cm apart.
TYPE LOCATION: San Bernardino County, California; approximately 2.7 kilometers north and 2.7 kilometers east of the junction of Mountain Pass Road and Interstate 15; 215 meters north and 390 meters east of the southwest corner of Sec.20, T.16 N, R.14 E, San Bernardino Meridian; USGS Mineral Hill, California 7.5 minute topographic quadrangle; 35 degrees, 29 minutes, 32 seconds North and 115 degrees, 29 minutes, 57 seconds West, UTM 11S 636136e, 3928673n; (DTM:NAD83).

RANGE IN CHARACTERISTICS:

Soil moisture - Usually dry, moist in some part for short periods during winter and early spring and for 10 to 20 days cumulative between July to September following summer convection storms; Typic-aridic moisture regime.

Soil temperature - 15 to 20 degrees C (59 to 68 degrees F).
Depth to lithic contact - 10 to 35 centimeters (4 to 14 inches).

Control Section

Percent clay: Averages 10 to 18 percent.
Rock fragments: Averages 11 to 28 percent, mainly gravel.

A horizon
Hue: 7.5YR or 10YR.
Value: 3 to 5 dry, 3 or 4 moist.
Chroma: 3 or 4.
Texture of the fine earth fraction: loamy sand or sandy loam.
Clay: 5 to 11 percent.
Rock fragments: averages 10 to 35 percent, mainly gravel.
Reaction: neutral to moderately alkaline

Bt horizon
Hue: 5YR, 7.5YR, or 10 YR.
Value: 3 to 5 dry, 3 or 4 moist.
Chroma: 3 to 6.
Clay: 10 to 18.
Rock fragments: averages 10 to 30 percent, mainly gravel.
Reaction: neutral to slightly alkaline

COMPETING SERIES: These are the Aftaden (NM), Paradise Spring (CA), Sparkhule (CA), Stonegold (CA), and Zyplar (NV). Aftaden soils have a climate typical of the Chihuahuan desert and are formed from basalt. Paradise Spring and Zyplar soils have 20 to 30 percent clay throughout the particle size control section and Paradise Spring soils are shallow to bedrock. Sparkhule soils are shallow and contain more than 25 percent clay in the particle size control section. Stonegold soils are formed from basalt.

GEOGRAPHIC SETTING: Copperworld soils are on mountains. Slopes are 30 to 60 percent. These soils formed in residuum and colluvium weathered from metavolcanic rock. Elevation is 980 to 1600 meters (3215 to 5250 feet). Mean annual precipitation is 100 to 175 mm, (4 to 7 inches). The mean annual temperature is 13 to 18 C (55 to 64 degrees F). Frost free season is 210 to 270 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lithic Torriorthents. The Lithic Torriorthent soils are on south facing backslopes of hills and lack an argillic horizon.

DRAINAGE AND PERMEABILITY: Well drained; medium or high runoff; moderately rapid permeability above the bedrock.

USE AND VEGETATION: Rangeland and wildlife habitat. Vegetation is mainly blackbrush, big galleta, creosotebush, and other shrubs.

DISTRIBUTION AND EXTENT: Mojave Desert of southeastern California. The soils are of moderate extent. MLRA: 30.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA

SERIES ESTABLISHED: San Bernardino County, Clark Mountain Grazing Allotment, part of the Mojave Desert, northeast area, California, 2006. The name is from the nearby Copperworld mine.

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

1. Ochric Epipedon: 0 to 3 cm (0 to 1 inches).
2. Particle Size Control Section for this pedon: 0 to 15 cm (0 to 6 inches). (A and Bt
horizons)
3. Argillic horizon: 3 to 15 cm (1 to 6 inches)
4. Lithic contact: 15 cm (6 inches). (R horizon)

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 5/2007. ET

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National Cooperative Soil Survey
U.S.A.