LOCATION CHUMASH CAEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, nonacid, thermic, shallow Typic Xerorthents
TYPICAL PEDON: Chumash gravelly loam, on the side of a mountain at an elevation of 1110 feet. (Colors are for dry soil unless otherwise noted).
A--0 to 7 inches (0 to 18 centimeters); yellowish brown (10YR 5/4) gravelly loam, dark yellowish brown (10YR 3/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine tubular pores; 15 percent fine and medium subangular gravel; neutral (pH 6.8); clear wavy boundary. (4 to 14 inches thick).
Cr--7 to 22 inches (18 to 55 centimeters); highly fractured, bedded, weathered shale with fractures 1 to 3 inches apart, and with about 10 to 15 percent soil in fractures with common very fine roots.
TYPE LOCATION: Ventura County, California; in an unsectionalized area 1/2 mile south of Laguna Peak; Latitude 34 degrees, 6 minutes, 7 seconds north and Longitude 119 degrees, 3 minutes, 54 seconds west; Point Mugu 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 soft rock: 4 to 14 inches (10 to 35 centimeters).
A horizon--10YR 5/4, 6/2, 6/3 and 10YR 3/4, 4/2, 4/3 moist.
Clay percentage--ranges from 12 to 27 percent and averages 18 to 27 percent.
Coarse fragments--15 to 30 percent.
COMPETING SERIES: These are the Cieneba, Gillander, and Trigo series. Cieneba soils have 15 to 25 percent coarse and very coarse sand and have Cr horizons comprised of acid granitic material. Gillander soils have AC horizons and have influence in the profile of small amounts of ash. Trigo series have Cr horizons comprised of consolidated stratified alluvial sediments and can have 2.5Y colors within the profile.
GEOGRAPHIC SETTING: Chumash soils are on hills and mountains. The soils formed in residuum and colluvium derived from inter-bedded shale and sandstone. Slopes are 5 to 75 percent. The elevation is 10 to 1570 feet. The mean annual precipitation is 14 to 18 inches with warm, dry summers and cool, moist winters. The mean annual temperature is 60 to 64 degrees F. The frost-free season is 290 to 350 days.
GEOGRAPHICALLY ASSOCIATED SOILS: There are the Boades(T) and Malibu soils. Both these soils have mollic epipedons on the side slopes of hills and mountains.
DRAINAGE AND PERMEABILITY: Well drained; low to high runoff; moderate permeability.
USE AND VEGETATION: Wildlife habitat, recreation, cattle production and building site development. Vegetation is California sagebrush, purple sage, white sage, black sage, buckwheat, golden bush and deerweed.
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: Ventura County, California, 1999.
REMARKS: The series name is from the local American Indian tribe. Diagnostic horizons and features recognized in this pedon:
Ochric epipedon--The zone from the soil surface to a depth of about 7 inches (A horizon).
Paralithic material--The zone from a depth of 7 inches to about 22 inches (Cr horizon)