LOCATION SELBY CA

Tentative Series
Rev. MRS/KDA/KP
12/2022

SELBY SERIES

The Selby series consists of moderately deep, well drained soils that formed in material weathered from sedimentary and metamorphic rock. These soils are on hillslopes. Slope is 30 to 75 percent. The mean annual precipitation is about 381 mm (15 in) and the mean annual temperature is about 16 degrees C (61 degrees F).

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Typic Argixerolls

TYPICAL PEDON: Selby very cobbly-loam, on a hillslope with a southwest aspect, at an elevation of 960 meters (3,150 feet). (Colors are for dry soil unless otherwise stated. When described on June 12, 1991, the soil was dry throughout.)

A--0 to 8 cm (0 to 3 in); brown (7.5YR 5/2) gravelly loam, dark brown (7.5YR 3/2) moist; 17 percent clay; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; 20 percent gravel and 30 percent cobbles; neutral (pH 7.0); abrupt wavy boundary. (5 to 13 cm [2 to 5 in] thick)

Bt1--8 to 20 cm (3 to 8 in); brown (7.5YR 5/3) gravelly loam, dark brown (7.5YR 3/3) moist; 15 percent clay; moderate medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine roots; common very fine tubular pores; many distinct clay films on faces of peds and along surfaces of pores; 30 percent gravel and 20 percent cobbles; moderately alkaline (pH 8.0); clear wavy boundary. (10 to 15 cm [4 to 6 in] thick)

Bt2--20 to 41 cm (8 to 16 in); brown (7.5YR 5/2) very gravelly sandy clay loam, dark brown (7.5YR 3/2) moist; 25 percent clay; moderate medium subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; few very fine roots; few very fine tubular pores; many distinct clay films on faces of peds and along surfaces of pores; 30 percent gravel and 25 percent cobbles; moderately alkaline (pH 8.0); abrupt wavy boundary. (15 to 25 cm [6 to 10 in] thick)

Bt3--41 to 51 cm (16 to 25 in); light yellowish brown (10YR 6/4) extremely cobbly sandy loam; dark yellowish brown (10YR 4/4) moist; massive; 11 percent clay; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; few very fine tubular pores; 40 percent gravel and 30 percent cobbles; moderately alkaline (pH 8.0); abrupt irregular boundary. (18 to 28 cm (7 to 11 in] thick)

R--51 cm (25 in); very strongly cemented gabbro .

TYPE LOCATION: Kern County, California, Southwest Part; in map unit 591, Geghus-Selby complex, 30 to 75 percent slopes, about 549 meters (1,800 feet) north and 671 meters (2,200 feet) east of the southwest corner of section 21, T. 10 N., R. 22 W.; San Bernardino Base and Meridian; latitude 34 degrees 56 minutes 07 seconds north and longitude 119 degrees 14 minutes 18 seconds west; USGS Eagle Rest Peak, California, Quadrangle, NAD83.

RANGE IN CHARACTERISTICS:

Soil temperature: Average annual is 16 to 18 degrees C (61 to 65 degrees F) and the soil temperature is never below 8 degrees C (47 degrees F). The soils have a thermic temperature regime.

Soil moisture: The soils have a xeric soil moisture regime. The soil moisture control section is dry throughout from about mid April to mid December and is never moist more than 90 consecutive days.

Diagnostic feature(s):
Mollic epipedon thickness: 20 to 50 cm
Argillic horizon thickness: 10 to 35 cm
Depth to lithic contact: 50 to 100 centimeters

Particle size control section weighted average:
Rock fragments: 35 to 70 percent
Clay content: 18 to 35 percent

Surface fragments: 10 to 40 percent gravel and 10 to 40 percent cobbles consisting of metamorphic and/or sedimentary rock.

A horizon:
Hue: 10YR or 7.5YR dry and moist
Value: 5 dry and 3 moist
Chroma: 2 or 3 dry or moist
Texture of the fine earth fraction: loam
Content of clay: 10 to 25 percent
Content of organic matter: 1.0 to 3.0 percent
Reaction: neutral or slightly alkaline
Content of rock fragments: 30 to 70 percent
10 to 30 percent gravel
20 to 40 percent cobbles

Bt horizons:
Hue: 10YR or 7.5YR dry and moist
Value: 5 or 6 dry, 3 or 4 moist
Chroma: 2 to 4, dry or moist
Texture of the fine earth fraction: sandy loam, loam, sandy clay loam, clay loam
Content of clay: 8 to 35 percent
Content of organic matter: 0.1 to 2.0 percent
Reaction: slightly alkaline or moderately alkaline
Content of rock fragments: 30 to 90 percent
10 to 50 percent gravel
10 to 40 percent cobbles

COMPETING SERIES: These are the Brecken and Togasara series. Brecken (MLRA 17) soils are very deep, formed in mixed alluvium on dissected terraces, and have a xeric soil moisture regime that borders on aridic. Togasara (MLRA 15) soils are very deep and formed in mixed alluvium on hills of terraces.

GEOGRAPHIC SETTING: The Selby soils are on hillslopes. Slope is 30 to 75 percent. The Selby soils formed in material weathered from sedimentary and metamorphic rock. Elevations are 774 to 1,480 meters (2,535 to 4,855 feet). The climate is arid with hot dry summers and cool, somewhat moist winters. The mean annual precipitation is 254 to 508 mm (10 to 20 in). The mean annual air temperature is 14 to 18 degrees C (57 to 65 degrees F). Mean July temperature is about 29 degrees C (85 degrees F), and mean January temperature is about 8 degrees C (47 degrees F). The frost-free season is 150 to 225 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bitcreek, Dibble, Eaglerest, Geghus, Harrisranch, and Positas soils. Bitcreek soils, on linear to convex backslopes of hillslopes, are very deep and have a fine-loamy particle-size class. Dibble soils, on convex hillslopes, have a fine particle-size class and have a smectitic mineralogy class. Eaglerest soils, on concave shoulders of mountain slopes, are shallow. Geghus soils, on hillslopes and mountain slopes, are very deep and have a fine-loamy particle-size class. Harrisranch soils, on linear to convex mountain slopes, are very deep and have a coarse-loamy particle-size class. Positas soils, on linear stream terraces, are very deep, have a fine particle-size class, and have a smectitic mineralogy class.

DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Selby soils are used for livestock grazing. Native vegetation is California juniper, perennial buckwheat, yucca, wild oats, purple needle grass, filaree, and red brome.

DISTRIBUTION AND EXTENT: Along the rim of the Southern San Joaquin Valley of California, MLRA 17. The series is not extensive.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES PROPOSED: Kern County, California, 1992.

REMARKS:
Particle size control section for this pedon: 20 to 41 cm
Diagnostic horizons and features recognized in the profile are:
Mollic epipedon 0 to 41 cm
Argillic Horizon 20 to 41 cm

Soil classified using the 12th Edition of the Keys to Soil Taxonomy.

National Cooperative Soil Survey
U.S.A.