LOCATION CORBILT                 NV

Established Series
Rev. HJB/RLB/WED/TM/ET
04/2015

CORBILT SERIES

The Corbilt series consists of deep, well drained soils on alluvial fans, fan skirts and fan piedmonts. They formed in mixed alluvium. Slopes are 0 to 8 percent. The mean annual precipitation is about 125 millimeters (5 inches) and the mean annual temperature is about 18 degrees C. (64 degrees F.).

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Duric Haplocalcids

TYPICAL PEDON: Corbilt very gravelly sandy loam - rangeland. Colors are for dry soil unless otherwise noted. The soil surface is covered by approximately 50 percent gravel overlain by a patchy 1 to 2.5 centimeter (1/2 to 1 inch) thick mantle of windblown sand.

A--0 to 10 centimeters (0 to 4 inches); very pale brown (10YR 7/3) very gravelly sandy loam, yellowish brown (10YR 5/4) moist; strong coarse platy structure; soft, very friable, nonsticky and nonplastic; few very fine roots; many very fine, common fine, and few medium vesicular pores; 35 percent gravel; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (8 to 10 centimeters thick)

Bk--10 to 41 centimeters (4 to 16 inches); very pale brown (10YR 7/3) gravelly fine sandy loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, few fine and medium roots; common very fine interstitial pores; 15 percent gravel; few thin calcium carbonate masses on faces of peds and gravel; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (25 to 50 centimeters thick)

Bqk--41 to 81 centimeters (16 to 32 inches); very pale brown (10YR 7/3) gravelly fine sandy loam, light yellowish brown (10YR 6/4) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine, few fine and medium roots; common very fine and few fine interstitial pores; few fine masses weakly cemented by calcium carbonate and silica; silica-calcium carbonate pendants on undersides of most rock fragments; few fine calcium carbonate filaments; 20 percent gravel; violently effervescent; strongly alkaline (pH 8.6); clear wavy boundary. (38 to 60 centimeters thick)

2Bkq--81 to 142 centimeters (32 to 56 inches); very pale brown (10YR 7/3) very gravelly sandy loam, light yellowish brown (10YR 6/4) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine roots; common very fine and few fine interstitial pores; few scattered pockets (15 to 20 centimeters (6 to 8 inches) diameter) of loamy coarse sand; few thin (up to 2.5 centimeters (1 inch) thick), discontinuous weakly cemented silica and calcium carbonate layers, lime-silica pendants on underside of most rock fragments; few fine calcium carbonate filaments; few, prominent, calcium carbonate coats on top and bottom of rock fragments; 30 percent gravel, 5 percent cobbles, 5 percent stones; violently effervescent; strongly alkaline (pH 8.8); clear wavy boundary. (25 to 75 centimeters thick)

2Bkqm--142 to 152 centimeters (56 to 60 inches); very pale brown (10YR 8/3) strongly cemented duripan, very pale brown (10YR 7/4) moist; massive; 40 percent gravel, 5 percent cobbles; violently effervescent.

TYPE LOCATION: Nye County, Nevada; approximately 3.2 kilometers (2 miles )east of Amargosa Valley (formerly Lathrop Wells) and one-third mile north of U.S. 95 and about 259 meters (850 feet) south and 152 meters (500 feet) east of the northwest corner of sec. 21, T. 15 S., R., 50 E.; USGS Striped Hills, NV 7.5 minute topographic quadrangle; 36 degrees, 38 minutes, 21 seconds north latitude and 116 degrees, 21 minutes, 54 seconds west longitude; UTM 11S, 556774 e, 4055032 n; NAD 83.

RANGE IN CHARACTERISTICS:

Soil moisture: Usually dry, the upper part of the moisture control section is moist for a very short time in late winter. The soils have a typic-aridic soil moisture regime. The ratio of soil moisture for evapotranspiration between summer and winter is about 0.4:1, typical of the Mojave Desert.

Soil temperature: 17 to 21 degrees C. (63 to 69 degrees F.).

Depth to duripan: 100 to 150 centimeters (40 to 60 inches).
Depth to calcic horizon: 33 to 60 centimeters (13 to 24 inches).


Other features: Some pedons do not have a thin mantle of eolian sand on the surface.

Control section
Clay content: 5 to 10 percent.
Rock fragments: Averages 15 to 35 percent.

A horizon:
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 3 or 4 dry or moist.

Bk horizon:
Structure: Subangular blocky or massive.
Texture: Fine sandy loam or sandy loam.
Effervescence: Strongly effervescent or violently effervescent.
Reaction: Moderately alkaline or strongly alkaline.
Calcium carbonate equivalent in the fine earth fraction: 5 to 10 percent.

Bqk horizon:
Consistence of matrix: Soft dry, very friable moist.
Texture: Fine sandy loam, sandy loam, gravelly fine sandy loam or gravelly sandy loam.
Reaction: Strongly alkaline or very strongly alkaline.
Calcium carbonate equivalent in the fine earth fraction: 15 to 20 percent.
Secondary visible calcium carbonate: 5 to 20 percent.

Other features: Weakly cemented masses constitute up to 20 percent. In some pedons the matrix is effervescent and cemented patches are violently effervescent.

2Bqk horizon:
Rock fragments: 30 to 50 percent gravel, 0 to 7 percent cobbles, 0 to 7 percent stones.
Texture: Gravelly sandy loam, gravelly fine sandy loam, very gravelly sandy loam or very gravelly fine sandy loam.
Consistence: Soft dry, very friable moist.
Calcium carbonate equivalent in the fine earth fraction: 10 to 20 percent.

Other features: Silica-calcium carbonate cemented plates comprise up to 20 percent. Some pedons contain 20 percent or more hard calcium carbonate nodules and concretions.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Corbilt soils are on alluvial fans, fan skirts, and fan piedmonts. These soils formed in mixed alluvium. Slopes are 0 to 8 percent. Elevations are 700 to 1375 meters (2,300 to 4,500 feet). The climate is typical of the Mojave Desert, with hot, dry summers and cool, moist winters. The mean annual precipitation is 75 to 125 centimeters (3 to 5 inches). The mean annual air temperature is 16 to 20 degrees C. (60 to 68 degrees F.). The frost-free season is 200 to 220 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alko, Arizo, and Skelon soils. Alko and Skelon soils have a duripan within a depth of 100 centimeters (40 inches). Arizo soils have control sections that average more than 35 percent rock fragments. Bluepoint soils have a sandy control section.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; slow to medium runoff; moderately rapid permeability; high saturated hydraulic conductivity.

USE AND VEGETATION: These soils are used for rangeland and wildlife habitat. The present vegetation is mainly creosotebush, spiny hopsage, Indian ricegrass and white bursage.

DISTRIBUTION AND EXTENT: Mojave Desert of southern Nevada; MLRA 30. These soils are not extensive.

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

SERIES ESTABLISHED: Nye County, Nevada. (Southwest Part) 1994. The name is coined.

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

Ochric epipedon - 0 to 10 centimeters (0 to 4 inches) (A horizon).
Calcic horizon - 41 to 142 centimeters (16 to 56 inches) (Bqk and 2Bkq horizons).
Duripan - 142 to 152 centimeters (56 to 60 inches) (2Bkqm horizon).
Particle-size control section - 25 to 100 centimeters (10 to 40 inches) (Bkq, part of the Bk and 2Bkq horizons).

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 4/2011. ET

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National Cooperative Soil Survey
U.S.A.