LOCATION SOUTHLAKE CATentative Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Xeric Haplargids
TYPICAL PEDON: Southlake stony sandy loam on an 8 percent north slope under a cover of California juniper, red brome, rubber rabbitbrush, and annual forb vegetation at an elevation of 3,270 feet. (Colors are for dry soil unless otherwise stated. When described on May 12, 1981, the soil was dry throughout).
A1--0 to 1 inch; brown (10YR 5/3) stony sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine roots; common very fine interstitial pores; 6 percent stones, 5 percent cobbles, and 10 percent gravel; neutral (pH 6.8); abrupt smooth boundary. (1 to 3 inches thick)
A2--1 to 6 inches; brown (10YR 5/3) stony sandy loam, very dark grayish brown (10YR 3/2) moist; moderate coarse subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and few fine roots; common very fine interstitial pores; 6 percent stones, 5 percent cobbles, and 10 percent pebbles; neutral (pH 7.0) abrupt wavy boundary. (4 to 8 inches thick)
Bt1--6 to 15 inches; yellowish brown (10YR 5/4) very stony sandy loam, dark brown (10YR 3/3) moist; moderate coarse and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular pores; common thin clay films bridging mineral grains and in pores; 15 percent stones, 15 percent cobbles, and 10 percent gravel; neutral (pH 7.0); clear wavy boundary. (8 to 10 inches thick)
Bt2--15 to 40 inches; brown (7.5YR 5/4) very stony sandy clay loam, dark brown (7.5YR 4/4) moist; strong coarse and medium angular blocky structure; very hard, firm, sticky and plastic; few very fine roots; few very fine tubular pores; continuous thin clay films bridging mineral grains and few moderately thick clay films on peds and in pores; 15 percent stones, 15 percent cobbles, and 10 percent gravel; neutral (pH 7.0); clear wavy boundary (15 to 22 inches thick)
Bt3--40 to 60 inches; brown (7.5YR 5/4) very stony sandy clay loam, dark brown (7.5YR 4/4) moist; moderate fine and medium subangular blocky structure; very hard, friable, sticky and slightly plastic; few fine roots; common very fine interstitial and few very fine tubular pores; many thin clay films on peds, in pores, and bridging mineral grains; 20 percent stones, 20 percent cobbles, and 15 percent gravel; neutral (pH 7.0).
TYPE LOCATION: Kern county, California. about 2 miles southeast of the town of South Lake; about 2,100 feet east and 1,800 feet south of the northwest corner of Section 33, T.26S., R.34E. MDB&M. Weldon, California Quadrangle; lat. 35 degrees 37 minutes 31 seconds N and 118 degrees 20 minutes 09 seconds W.
RANGE IN CHARACTERISTICS: The soil between depths of 9 and 28 inches is dry from April 15th to November 30th. It is usually moist in some part for about 85 days when the soil temperature is above 5 degrees C. It is continuously moist in the moisture control section for about 50 days when the soil temperature is above 8 degrees C. The moisture regime is aridic but it borders on xeric. The mean annual soil temperature is 59 to 63 degrees F. The soil surface is covered with 25 to 35 percent rock fragments consisting of 0 to 2 percent boulders, 0 to 15 percent stones, 3 to 15 percent cobbles, and 10 to 30 percent gravel. Reaction is neutral or mildly alkaline.
The A horizon has dry color of 10YR 5/3 or 5/4, and moist color of 10YR 3/2 or 3/3. Textures are stony or gravelly sandy loam. It contains 15 to 35 percent rock fragments consisting of 0 to 15 percent boulders and stones, 0 to 10 percent cobbles, and 10 to 30 percent gravel. The organic matter content averages 0.5 to 1.0 percent for the surface 15 inches. Clay content is 5 to 15 percent.
The Bt horizon has dry color of 10YR 5/3, 5/4; 7.5YR 4/6, 5/6, 5/4 or 6/4 and moist color of 10YR 3/3, 3/4, 4/4; 7.5YR 4/4, 4/6 or 5/4. Textures of the B horizon are very stony or very gravelly sandy clay loam, sandy loam or coarse sandy loam. The horizon contains 35 to 60 percent rock fragments consisting of 5 to 30 percent stones and boulders, 10 to 20 percent cobbles, and 10 to 35 percent gravel. Clay content is 18 to 35 in the upper part and as low as 10 percent in the lower part.
COMPETING SERIES: These are the Lubkin and Tinemaha series. Tinemaha soils have less than 0.4 percent organic carbon. Lubkin soils have less than 15 percent clay in the Bt horizon.
GEOGRAPHIC SETTING: Southlake soils are on sloping alluvial fans and fan terraces at elevations of 2,600 to 5,000 feet. They formed in mixed alluvium from granitic and metamorphic rock sources. Slopes are 2 to 15 percent. The mean annual precipitation is 7 to 10 inches and the mean annual temperature is 57 to 62 degrees F. The frost-free season is 180 to 225 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chollawell(T), and Inyo(T) soils. Chollawell soils have a coarse-loamy textural control section. Inyo soils are sandy and lack an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow or medium runoff; moderately slow permeability.
USE AND VEGETATION: Used for grazing, wildlife habitat, and homesite development. The vegetation is mainly red brome, Arabian schismus, filaree, California juniper, rubber rabbitbrush and Mojave buckwheat. Some areas have scattered digger pine.
DISTRIBUTION AND EXTENT: Valleys in the southern Sierra Nevada in California. The soils are of small extent in MLRA 29.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Kern County, California, 1995; Kern County, Northeastern Part and Southeastern Part of Tulare County Soil Survey. Source of name is the town of South Lake.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon -- the zone from 0 to 6 inches (A1,A2)
Argillic horizon -- the zone from 6 to 60 inches
(Bt1,Bt2,Bt3)
This soil was formerly classified as a Haploxeralf. The organic carbon content averages about 0.4 percent for the surface 10 inches - Lincoln Lab data.