LOCATION COTHARIN CAEstablished Series
TAXONOMIC CLASS: Loamy, smectitic, thermic, shallow Entic Haploxerolls
TYPICAL PEDON: Cotharin loam, on the side of a mountain at an elevation of 740 feet. (Colors are for dry soil unless otherwise noted).
Oe--0 to 1 inches (0 to 2.5 centimeters); partially decomposed Big Pod Ceonothus leaves and few fine to medium pieces of charcoal.
A--1 to 9 inches (2.5 to 23 centimeters); brown (10YR 4/3) loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine through coarse roots; few fine tubular pores; 5 percent fine and medium subangular gravel; 5 percent fine subangular pararock fragments; neutral (pH 7.0); clear smooth boundary. (2 to 13 inches thick)
AC--9 to 11 inches (23 to 28 centimeters); dark yellowish brown (10YR 4/4) loam, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine through coarse roots; few fine tubular pores; 5 percent fine and medium subangular gravel; 5 percent fine subangular pararock fragments; neutral (pH 7.0); clear smooth boundary. (0 to 4 inches thick)
Cr--11 to 60 inches (28 to 150 centimeters); highly fractured meta-volcanic rock with fractures 1 to 3 inches apart, and with about 10 to 15 percent soil in fractures with few very fine through coarse roots.
TYPE LOCATION: Ventura County, California; about 1 1/4 miles west Arroyo Sequit and 500 feet northeast of Mulholland Highway; 3750 feet east and 700 feet south of the northwest corner of section 18, T. 1 S., R. 19 W.; Latitude 34 degrees, 5 minutes, 14 seconds north and Longitude 118 degrees, 54 minutes, 42 seconds west; Triunfo Pass Quadrangle.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 62 to 66 degrees F.
Soil moisture: Soil is moist in middle to late November to late May.
Depth to paralithic contact: 4 to 14 inches (10 to 35 centimeters).
Organic matter content: 2 to 4 percent.
A horizon--10YR 5/2, 5/3, 4/2, 4/3 and 10YR 3/2, 3/3 moist.
Texture--Loam or clay loam.
Clay percentage--18 to 35 percent.
Coarse fragments--5 to 15 percent.
AC horizon is absent in some pedons.
COMPETING SERIES: There are no other soils in this family.
GEOGRAPHIC SETTING: Cotharin soils are on side slopes of hills and mountains. These soils formed in residuum and colluvium derived from meta-volcanic rock. Slopes are 5 to 75 percent. Elevations are 380 to 3110 feet. The climate is characterized by warm, dry summers and cool, moist winters. The mean annual precipitation is 18 to 24 inches, the mean annual temperature is 60 to 64 degrees F., and the frost free season is to 290 to 350 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Talepop (T) and Kayiwish (T) soils. Talepop soils have argillic horizons and Kayiwish soils have more than 35 percent clay in the solum.
DRAINAGE AND PERMEABILITY: Well drained; low to very high runoff; moderate to moderately slow permeability.
USE AND VEGETATION: Wildlife habitat, recreation and building site development. Vegetation is Big Pod ceonothus, chamise ceonothus, and miscellaneous forbs and grasses.
DISTRIBUTION AND EXTENT: Ventura County and Los Angeles County, California. The soil is moderately extensive. MLRA 20.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES PROPOSED: Los Angeles County, California, 1999.
REMARKS: The series name is from a local road. Diagnostic horizons and features recognized in this pedon:
Mollic epipedon--The zone from the soil surface to a depth of about 9 inches (A horizon).
Paralithic material--The zone from a depth of 11 inches to about 60 inches (Cr horizon)
ADDITIONAL DATA: National Soil Survey Laboratory Characterization S99CA-111-003.