LOCATION CALLEGUAS CAEstablished Series
The Calleguas series consists of very shallow and shallow, well drained soils formed on uplands, hills and mountains in material weathered from sedimentary rocks. Calleguas soils have slopes of 9 to 75 percent. The mean annual precipitation is about 406 millimeters (16 inches) and the mean annual air temperature is about 16 degrees C (60 degrees F).
TAXONOMIC CLASS: Loamy, mixed, superactive, calcareous, thermic, shallow Typic Xerorthents
TYPICAL PEDON: Calleguas channery clay loam, rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 8 centimeters (0 to 3 inches); light brownish gray (10YR 6/2) channery clay loam, dark grayish brown (10YR 4/2) moist; moderate fine granular structure; slightly hard, very friable, sticky and plastic; many very fine and fine roots; many very fine interstitial pores; about 20 percent shale fragments; strongly effervescent, lime disseminated; moderately alkaline (ph 8.0); abrupt smooth boundary. (5 to 10 centimeters (2 to 4 inches) thick)
A2--8 to 41 centimeters (3 to 16 inches); light brownish gray (10YR 6/2) channery clay loam, dark grayish brown (10YR 4/2) moist; moderate fine granular structure; slightly hard, very friable, sticky and plastic; many very fine and fine roots; many very fine interstitial pores; about 34 percent shale fragments; strongly effervescent, lime disseminated; moderately alkaline (ph 8.0); gradual irregular boundary. (15 to 41 centimeters (6 to 16 inches) thick)
Cr--41 to 61 centimeters (16 to 24 inches); soft calcareous shale.
TYPE LOCATION: Los Angeles County, California; Las Virgenes Canyon; 1,500 feet north and 2,400 feet east of SW corner section 18, T.1N., R.17W. SBBM. USGS Malibu Beach, California, Quad; latitude 34 degrees, 06 minutes, 33 seconds N and long. 118 degrees, 43 minutes, 15 seconds W.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact of shale and sandstone is 20 to 51 centimeters (8 to 20 inches). The mean annual soil temperature is about 16 to 18 degrees C (60 to 65 degrees F). and the soil temperature usually is not below 8 degrees C (47 degrees F). at any time. The soil below a depth of about 13 centimeters (5 inches) is usually dry all of the time from May 1 until December 15 and is moist in some or all parts all the rest of the year. Rock fragments are mainly angular and subangular pieces of shale 0.6 to 1 centimeters (0.25 to 0.5 inches) in diameter. Most fragments can be crushed by earthmoving machinery. Rock fragment average 5 to 35 percent of the soil volume and are usually most numerous just above the paralithic contact. Distinct horizon differentiation is lacking.
The soil is 10YR 6/2, 6/3, 5/2, 5/3; 2.5YR 6/2. Moist value is 4/2, 4/3, 4/4, and 2.5 4/2. It is loam, clay loam, silty clay loam, channery loam, channery clay loam, or channery silty clay loam. The soil is slightly to violently effervescent throughout except in some pedons deeper than 25 centimeters (10 inches) the upper few inches are noneffervescent. Reaction is slightly or moderately alkaline.
COMPETING SERIES: There are no other series in this family. Soil series of similiar families include chumash, Cieneba and Trigo soils. Cieneba, chumash, and Trigo soils are noncalcareous in all parts.
GEOGRAPHIC SETTING: The Calleguas soils are on exposed and often eroded south-facing slopes. Slopes are 9 to 75 percent. Elevations are 30 to 853 meters (100 to 2,800 feet). The soils formed in material weathered from sandstone, shale, and mudstone. The climate is dry subhumid with warm dry summers and cool moist winters. Mean annual precipitation is 254 to 508 millimeters (10 to 20 inches). Average January temperature is 10 to 11 degrees C (50 to 52 degrees F); average July temperature is 19 to 23 degrees C (67 to 73 degrees F); mean annual temperature is 14 to 17 degrees C (58 to 62 degrees F). The frost-free season is 175 to 330 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Balcom, Castaic, Fontana, Linne, Saugus and Arnold soils. Arnold soils are sandy and lack a paralithic contact within 100 centimeters (40 inches) of the surface. Balcom and Castaic soils have a cambic horizon. Fontana and Linne soils have a mollic epipedon. Saugus soils are deep and Arnold soils have sandy textures throughout
DRAINAGE AND PERMEABILITY: Well-drained; medium or high runoff; moderate permeability.
USE AND VEGETATION: Used for grazing and watershed. Vegetation is annual grasses and forbs with some shrubs of the coastal sagebrush group.
DISTRIBUTION AND EXTENT: Coast Range in the central and south-central part of California, MLRA 15 and 20. The soils are extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Los Angeles County, California, 1973.