LOCATION SAURIN CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Typic Haploxerolls
TYPICAL PEDON: Saurin clay loam, on a south facing convex slope of 18 percent under wild oat, ripgut brome, ryegrass, thistle, and filaree at elevation of 1,000 feet. (Colors are for dry soil unless otherwise stated. When described (12/13/76) the soil was moist throughout.)
A11--0 to 10 inches; yellowish brown (10YR 5/4) clay loam, dark brown (10YR 3/3) moist; strong very fine, fine and medium subangular blocky structure; hard, friable, sticky and plastic; many very fine and fine roots; many very fine interstitial and tubular pores; 5 percent pebbles; slightly acid (pH 6.3); clear smooth boundary. (5 to 11 inches thick)
A12--10 to 22 inches; yellowish brown (10YR 5/4) clay loam, dark brown (10YR 3/3) moist; moderate very fine, fine and medium subangular blocky structure; hard, friable, sticky and plastic; common very fine and fine roots; many very fine interstitial and tubular pores; 5 percent pebbles; slightly acid (pH 6.3); clear smooth boundary. (7 to 14 inches thick)
B2t--22 to 33 inches; yellowish brown (10YR 5/4) clay loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; hard, friable, sticky and plastic; few very fine roots; common very fine interstitial and tubular pores; few thin clay films in pores; 5 percent pebbles; slightly acid (pH 6.5); clear wavy boundary. (7 to 16 inches thick)
Cr--33 to 42 inches; fractured sandstone.
TYPE LOCATION: Marin County, California; San Geronimo area, 0.5 miles west of Bucheye Creek on fire road, 0.1 mile southeast on fire road from junction, 45 feet north of fire road on hillside.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact is 20 to 40 inches. The mean annual soil temperature is 59 degrees to 61 degrees F. The difference between mean summer and mean winter soil temperature is about 12 to 15 degrees F. The soil is dry throughout from mid-June until sometime in October and is moist the rest of the time. It is moderately acid or slightly acid. Organic matter is more than 1 percent but only to depths of less than 20 inches. Base saturation ranges from 60 to 90 percent but is more than 75 percent in all parts to a depth of at least 30 inches. Gravel ranges from 5 to 15 percent throughout the profile. Clay is 27 to 35 percent.
The A horizon has dry color of 10YR 5/2, 5/3 or 5/4 and moist color of 10YR 3/2 or 3/3.
The B horizon has dry color of 10YR 4/2, 5/2 or 5/4 and moist color of 10YR 3/2 or 3/3. It has weak or moderate subangular blocky structure, has a slight increase in clay over the A horizon and contains a few clay films.
COMPETING SERIES: This is the Tocaloma series in another family. Tocaloma soils have a mesic soil temperature.
GEOGRAPHIC SETTING: Saurin soils are on hills. Slopes are 2 to 75 percent. The soils formed in material weathered from fractured soft sandstone and shale. Elevations are from 50 to 1,500 feet. the climate is subhumid mesothermal with warm dry summers and cool moist winters. Mean annual precipitation is 25 to 40 inches. Mean January temperature is about 55 degrees F.; mean July temperature is about 63 degrees F.; mean annual temperature is about 58 degrees to 62 degrees F. Frost-free season is 270 to 320 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Tocaloma soils and the Bonnydoon, Los Osos and McMullin soils. Bonnydoon and McMullin soils are less than 20 inches deep to a lithic or paralithic contact. Los Osos soils have a fine argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow to very rapid runoff; moderate permeability.
USE AND VEGETATION: Used for rangeland, watershed, and wildlife habitat. Vegetation is annual grasses and forbs.
DISTRIBUTION AND EXTENT: Central coastal California. These soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Marin County, California, 1979.
REMARKS: The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET