LOCATION MALIBU CAEstablished Series
TAXONOMIC CLASS: Fine, vermiculitic, thermic Typic Palexerolls
TYPICAL PEDON: Malibu loam, on the side of a mountain at an elevation of 680 feet. (Colors are for dry soil unless otherwise noted).
A--0 to 19 inches (0 to 48 centimeters); brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots; common very fine through medium tubular pores; 10 percent fine and medium subangular gravel; 10 percent fine subangular pararock fragments; slightly acid (pH 6.4); abrupt smooth boundary. (10 to 20 inches thick).
2Bt--19 to 27 inches (48 to 68 centimeters); reddish brown (5YR 4/4) clay; dark reddish brown (5YR 3/4) moist; strong very coarse angular blocky structure; extremely hard, extremely firm, very sticky and very plastic; few very fine roots; 5 percent fine and medium subangular gravel; 5 percent fine subangular pararock fragments; slightly acid (pH 6.4); abrupt smooth boundary. (10 to 20 inches thick).
2Cr--27 to 60 inches (68 to 150 centimeters); highly fractured, bedded, weathered shale and sandstone with about 10 to 15 percent soil in fractures with common very fine roots.
TYPE LOCATION: Ventura County, California; about 1/2 mile northwest of Laguna Peak in an unsectionalized area; Latitude 34 degrees, 6 minutes, 43 seconds north and Longitude 119 degrees, 4 minutes, 16 seconds west; Point Mugu Quadrangle.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 62 to 66 degrees F.
Soil moisture: Soil is moist from middle to late November to July.
Depth to soft rock: 20 to 40 inches.
Reaction: Neutral or slightly acid.
A horizon--10YR 5/3, 5/2 and 10YR 3/3, 3/2 moist.
Clay percentage--18 to 27 percent.
Coarse fragments--10 to 15 percent.
Bt horizon-5YR 4/4, 4/6 or 7.5YR 4/4, 5/4 and 5YR 3/4, 4/4, 4/6 or 7.5YR 4/4
moist.
Clay percentage--40 to 55 percent.
Coarse fragments--0 to 10 percent.
COMPETING SERIES: There are no competing series in this family.
GEOGRAPHIC SETTING: Malibu soils are on side slopes of hills and mountains. These soils formed in residuum and colluvium derived from inter-bedded shale and sandstone. Slopes are 4 to 75 percent. Elevations are 10 to 1570 feet. The climate is characterized by warm, dry summers and cool, moist winters. The mean annual precipitation is 14 to 18 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 Chumash (T) and Boades (T) soils. Both these soils have bedrock within 20 inches of the soil surface and are on the side slopes of hills and mountains.
DRAINAGE AND PERMEABILITY: Moderately well drained; high to very high runoff; very slow 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 ESTABLISHED: Los Angeles County, California, Malibu Area, 1973.
REMARKS: The series name is from the city of Malibu. Type location was changed to another location in 1999 and classification was changed from Ultic to Typic (see additional data).
Diagnostic horizons and features recognized in this pedon:
Mollic epipedon--The zone from the soil surface to a depth of about 19 inches (A horizon).
Argillic horizon--The zone from a depth of 19 inches to about 27 inches (2Bt horizon).
Paralithic material--The zone from a depth of 27 inches to about 60 inches (2Cr horizon)
ADDITIONAL DATA: National Soil Survey Laboratory Characterization S99CA-111-002.