LOCATION TUNIS CAEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Typic Haploxerolls
TYPICAL PEDON: Tunis loam, annual grass range. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; brown (10YR 5/3) loam, dark brown (7.5YR 3/3) moist; moderate fine granular structure; slightly hard, friable, nonsticky and nonplastic; common very fine roots; common very fine vesicular and interstitial pores; slightly acid (pH 6.3); abrupt smooth boundary. (1 to 3 inches thick)
Bw--2 to 18 inches; brown (10YR 5/3) loam, dark brown (7.5YR 3/3) moist; weak fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine vesicular and interstitial pores; neutral (pH 7.0); abrupt wavy boundary. (9 to 17 inches thick)
Cr--18 to 24 inches; weathered metamorphosed igneous rock which slakes in water and calgon after 15 hours continuous shaking. The weathered rock is almost continuous with few seams or cracks. Roots do not extend into this layer.
TYPE LOCATION: Kern County, California; site is 1,000 feet west and 2,000 feet south of the southwest corner of sec. 15, T.l0N., R.l7W., SBB&M. Site is in a land grant area, that has not been surveyed into sections.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact with weathered metamorphic rock is 10 to 20 inches. The mean annual soil temperature is 59 degrees to 64 degrees F. The soil is dry in all parts for 45 or more consecutive days in the period from June 21 to October 21 in 6 out of 10 years. Rock fragments are less than 15 percent throughout the profile. Reaction ranges from slightly acid to mildly alkaline throughout.
The A horizon is dark gray, gray, grayish brown, brown, or dark brown (10YR 4/1, 5/1, 5/2, 5/3, 4/3) or brown or dark brown (7.5YR 5/2, 4/2, 3/2). It is loam or sandy loam and has 18 to 25 percent clay.
The Bw horizon is loam and sandy loam and has less than 18 percent clay. It is dark gray, gray, grayish brown, brown, or dark brown (10YR 4/1, 5/1, 5/2, 5/3, 4/3) and brown or dark brown (7.5YR 5/2, 4/2, 3/2). It has fine and medium subangular blocky structure.
The Cr horizon consists of highly weathered material from igneous and metamorphic rock which still retains evidence of the rock structure. A few hard pieces of the original hard rock remain. Few cracks exist.
COMPETING SERIES: These are the Bonnydoon, Caperton, Cieneba, Friant, Godde and Lodo series. Bonnydoon and Caperton soils lack a cambic horizon. Cieneba soils have less than 18 percent clay and less than one percent organic matter. Friant, Godde and Lodo soils have a lithic contact. Also, Godde soils have a mean annual soil temperature cooler than 59 degrees F.
GEOGRAPHIC SETTING: The Tunis soils are on mountainous uplands with gently sloping ridge tops at elevations of 1,000 to 5,800 feet. The soils formed in material weathered from metamorphic and igneous rocks. Gradients are 5 to 75 percent. The climate is mediterranean with cool moist winters and warm dry summers. Mean annual precipitation is 10 to 20 inches. Most of the moisture occurs as rain in the late autumn and winter. Some moisture falls as snow. Mean annual temperature is 57 degrees to 62 degrees F. Average January temperature is 39 degrees F., average July temperature is 72 degrees F. The freeze-free season is 150 to 225 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arujo and Walong soils as well as the competing Anaverde and Friant series. Arujo soils have a mollic epipedon more than 20 inches thick, an argillic horizon and have a paralithic contact at depths of 40 to 60 inches. Walong soils have a paralithic contact at depths of 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; medium to rapid runoff; moderate permeability.
USE AND VEGETATION: Used for watershed, recreation, wildlife, and limited range. Vegetation is annual grasses, a few perennial grasses, forbs, sparse low brush, and a few scattered scrub oaks. Some areas are bare and have been severely eroded.
DISTRIBUTION AND EXTENT: Central and southern Sierra Nevada foothills. The soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Rern County, California, Southeastern Part, 1976.
REMARKS: The Tunis soils in previous years were recognized as an eroded phase of the Sheridan series.
The Cr material is probably densic material as defined by Amendment 18 to the Keys to Soil Taxonomy.
OSED scanned by SSQA. Last revised by state on 8/96.