LOCATION BRECKEN CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Typic Argixerolls
TYPICAL PEDON: Brecken gravelly sandy loam on a southwest-facing slope of 47 percent under annual grasses at an elevation of 1,500 feet. (Colors are for dry soil unless otherwise noted. When described on July 20, 1994, the soil was dry with a slight amount of moisture below 19 inches.)
A--0 to 3 inches; brown (10YR 4/3) gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; hard, very friable, slightly sticky and nonplastic; common very fine roots; common very fine interstitial pores; 22 percent gravel, 5 percent cobbles and 3 percent stones; neutral (pH 6.8); abrupt smooth boundary. (2 to 9 inches thick)
Bt1--3 to 12 inches; dark brown (10YR 3/3) cobbly sandy loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; common very fine interstitial and few very fine tubular pores; few thin clay films bridging sand grains; 17 percent gravel, 12 percent cobbles and 3 percent stones; slightly alkaline (pH 7.6); clear smooth boundary. (4 to 15 inches thick)
2Bt2--12 to 19 inches; brown (10YR 4/3) very cobbly sandy clay loam, dark brown (10YR 3/3) moist; moderate coarse subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; common very fine roots; common very fine and few fine interstitial pores and common very fine tubular pores, few fine tubular pores; common moderately thick clay films bridging sand grains and few thin clay films lining pores and on faces of peds; 20 percent gravel, 35 percent cobbles and 3 percent stones; slightly alkaline (pH 7.6); clear smooth boundary. (5 to 18 inches thick)
2Bt3--19 to 39 inches; brown (10YR 4/3) extremely cobbly sandy loam, dark yellowish brown (10YR 3/4) moist; weak coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; common very fine interstitial and few very fine tubular pores; few thin clay films bridging sand grains; 30 percent gravel, 30 percent cobbles and 5 percent stones; slightly alkaline (pH 7.6); clear smooth boundary. (0 to 20 inches thick )
2BC--39 to 60 inches; dark yellowish brown (10YR 4/4) very cobbly coarse sandy loam, dark yellowish brown (10YR 3/4) moist; weak very coarse subangular blocky structure; soft, very friable, slightly sticky and nonplastic; few very fine roots; common very fine interstitial pores; 35 percent gravel, 20 percent cobbles and 5 percent stones; slightly alkaline (pH 7.4).
TYPE LOCATION: Kern County, California; about 13 miles east of Bakersfield between Breckenridge Road and U.S. Highway 178; 2000 feet east and 2100 feet south of the northwest corner of sec. 17, T. 29 S., R. 30 E.; USGS Rio Bravo Ranch topographic quadrangle; lat. 35 degrees 24 minutes 28 seconds N. and long. 118 degrees 46 minutes 55 seconds W.
RANGE IN CHARACTERISTICS:
Soil moisture: The soil between the depths of 6 to 18 inches
becomes moist about November 15 and remains
moist until about April 30. (xeric
moisture regime that borders on aridic).
Soil temperature: The mean annual soil temperature is 63 to
68 degrees F.
Rock fragments: 5 to 30 percent gravel, cobbles and stones in
the A horizon, mostly gravel. 35 to 70 percent
gravel, cobbles and stones throughout the rest
of the soil, mostly gravel and cobbles.
Depth to bedrock: more than 60 inches.
Reaction: neutral to moderately alkaline.
A horizon
Hue: 10YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 1, 2 or 3 dry, 1 or 2 moist.
Texture: sandy loam.
Clay: 10 to 20 percent.
Organic matter: 1 to 3 percent.
Upper Bt horizon (Bt1)
Hue: 10YR
Value: 3, 4 or 5 dry; 2 or 3 moist.
Chroma: 2 or 3 moist or dry.
Texture: very gravelly or cobbly sandy clay loam
or sandy loam.
Clay: 18 to 25 percent.
Organic matter: 1 to 2 percent
Lower Bt horizon (Bt2, Bt3)
Hue: 10YR
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2, 3 or 4 dry or moist.
Texture: Very cobbly or extremely cobbly sandy clay loam.
Clay: 20 to 35 percent.
Organic matter: less than 1 percent
BC horizon (where present)
Hue: 10YR.
Value: 4, 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4 dry or moist.
Texture: Very or extremely cobbly coarse sandy loam or
sandy clay loam.
Clay: 10 to 22 percent.
Some pedons have a C horizon with properties similar to the BC horizon.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Brecken soils are on escarpments and treads of dissected terraces with slopes of 15 to 60 percent. These soils formed in stratified mixed alluvium with some strata having large quantities of gravel and cobbles and other strata having smaller amounts. Elevation is 700 to 2,000 feet. The mean annual precipitation is 7 to 10 inches. The mean annual air temperature is 62 to 67 degrees F. Frost free period is 250 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pleito and Cuyama soils. Pleito soils have a mollic epipedon more than 20 inches thick and contain less than 25 percent coarse fragments. Cuyama soils do not have a dark surface; they contain less than 35 percent coarse fragments in the particle size control section.
DRAINAGE AND PERMEABILITY: Well drained, medium to rapid runoff, moderately slow permeability.
USE AND VEGETATION: These soils are used mostly for rangeland grazing but also for recreation, wildlife habitat, construction materials and homesites. Natural vegetation is annual grasses and forbs.
DISTRIBUTION AND EXTENT: Uplifted terraces bordering the western foothills of the southern Sierra Nevada mountains; MLRA 17. The soils of this series are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Kern County, California 1995; Kern County, Northeastern Part and Southeastern Part of Tulare County Soil Survey Area; California. The name is taken from Breckenridge Mountain.
REMARKS: Diagnostic horizons and features in this pedon include:
Mollic epipedon-from a depth of 0 to 12 inches (A and Bt1).
Argillic horizon-from a depth of 3 to 39 inches (Bt1, Bt2, and Bt3).