LOCATION BEARWALLOW CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Ultic Haploxeralfs
TYPICAL PEDON: Bearwallow loam - on a SE facing convex slope of 50 percent under wild oats, soft chess, and filaree at 680 feet elevation. (Colors are for dry soil unless otherwise stated. When described September 12, 1978, the soil was moist to a depth of 38 centimeters (15 inches) and dry below.)
A--0 to 20 centimeters (0 to 8 inches); reddish yellow (7.5YR 6/6) loam, strong brown (7.5YR 4/6) moist; moderate coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine and common fine tubular pores; common dark brown (10YR 3/3 moist) silt coatings on faces of peds; moderately acid (pH 5.8); clear wavy boundary. (10 to 23 centimeters thick)
BAt--20 to 38 centimeters (8 to 15 inches); reddish yellow (7.5YR 6/6) loam, dark brown (7.5YR 4/4) moist; moderate coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; common very fine and fine tubular pores; few faint clay films lining pores; few faint dark yellowish brown (10YR 3/4) silt coatings on faces of peds; moderately acid (pH 6.0); clear smooth boundary. (10 to 23 centimeters thick)
Bt1--38 to 69 centimeters (15 to 27 inches); reddish yellow (7.5YR 6/6) loam, yellowish red (5YR 5/6) moist; moderate coarse subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; common very fine roots; common very fine and fine tubular pores; many distinct clay films lining pores and common faint clay films on faces of peds; 10 percent 2 to 10 millimeters gravel; moderately acid (pH 5.8); gradual wavy boundary. (20 to 33 centimeters thick)
Bt2--69 to 89 centimeters (27 to 35 inches); reddish yellow (7.5YR 7/6) loam, yellowish red (5YR 5/6) moist; weak medium subangular blocky structure; slightly hard, firm, sticky and slightly plastic; few fine roots; few fine tubular pores; many distinct clay films lining pores and common faint clay films on faces of peds; 15 percent 2 to 15 millimeter gravel; moderately acid (pH 5.8); clear wavy boundary. (10 to 23 centimeters thick)
C--89 to 200 centimeters (35 to 79 inches); paragravel; moderately or weakly cemented, fractured sandstone with silt coatings in fractures. Fractures are 2 to 5 centimeters (1 to 2 inches) apart.
TYPE LOCATION: Mendocino County, California; 3,500 feet west of Highway 101 along farm road 4.2 miles south of Boonville-Ukiah cutoff; 1,600 feet south and 3,500 feet east of NW corner of Section 27, T. 14 N., R. 12 W. (Section lines projected), MDB&M, Elledge Peak Quad.
RANGE IN CHARACTERISTICS:
Soil moisture: dry throughout between a depth of 15 and 46 centimeters from June to October in most years, and usually moist from November to May. The soil has a xeric soil moisture regime.
Soil temperature: The mean annual soil temperature is 15 to 17 degrees C. The soil has a thermic temperature regime.
Depth to paralithic material with fractures less than 10 centimeters apart: 100 to 150 centimeters to moderately or weakly cemented material
Rock fragments: 0 to 15 percent throughout the profile, above the C horizon.
Base Saturation (by the ammonium acetate method): 50 to 90 percent throughout and is less than 75 percent within the Bt horizon.
A Horizon:
Hue: 7.5YR, 10YR
Value: 4 through 7, 3 through 5 moist
Chroma: 2 through 6 dry or moist
Clay content: 15 to 25 percent
Rock content: 0 to 15 percent
Reaction: moderately acid to neutral
Bt Horizon: 5YR, 7.5YR, 10YR
Hue: 6 to 7, 3 through 5 moist
Value: 3 through 6, 2 through 6 moist
Chroma: 3 through 6 dry or moist
Clay content: 20 to 35 percent
Rock content: 0 to 15 percent
Reaction: strongly to slightly acid
C Horizon:
Value: 3 through 6, 2 through 6 moist
Chroma: 3 through 6 dry or moist
Clay content: 20 to 35 percent
Hue: 5YR, 7.5YR, 10YR
Pararock content: 90 to 95 percent angular, moderately or weakly cemented paragravel
Reaction: strongly to slightly acid
COMPETING SERIES: These are the Churn (T CA), Loafercreek (CA), Mounthope (CA), Sommeyflat (CA), and Wisheylu (T CA) series. Churn soils lack paragravel textures below 100 centimeters. Loafercreek soils have hard bedrock above 100 centimeters. Mounthope and Sommeyflat soils formed in igneous rocks, Mounthope soils have a paralithic contact at 100 to 150 centimeters and Sommeyflat soils have a paralithic contact at 152 to 203 centimeters. Wisheylu soils have a paralithic contact of basic igneous bedrock at a depth of 50 to 100 centimeters and have 2.5Y hues in the lower profile.
GEOGRAPHIC SETTING: Bearwallow soils are on ridges and rolling side slopes of hills and mountains and have slopes of 5 to 75 percent. They formed in material weathered from sandstone or shale at elevations of 61 to 915 meters (200 to 3,000 feet). The climate is subhumid with hot dry summers and cool moist winters. Mean annual precipitation is 890 to 1650 millimeters (35 to 65 inches). Mean January temperature is about 7 degrees C (44 degrees F); mean July temperature is about 22 degrees C (72 degrees F); mean annual temperature is 12 to 15 degrees C (53 degrees to 59 degrees F). Frost-free period ranges from 150 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hellman and Witherell soils. Witherell soils are less than 20 inches deep to lithic material consisting of fractured sandstone. Hellman soils have greater than 35 percent clay in the particle-size control sections.
DRAINAGE AND PERMEABILITY: Well drained; medium to very high runoff; moderately slow permeability.
USE AND VEGETATION: Used for livestock grazing, watershed and wildlife habitat. Vegetation is wild oats, soft chess, filaree, burclover, ripgut brome and other annual grasses and forbs.
DISTRIBUTION AND EXTENT: Northern California in the Coast range. The soils are moderately extensive. MLRA 15.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Mendocino County, Eastern part, California, 1985.
REMARKS: The activity class was added to the classification in January of 2003. - ET. The depth class was changed to reflect the fracture spacing in the paralithic material in January 2008. - ET.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 20 centimeters (A)
Argillic horizon - the zone from 20 to 89 centimeters (BAt, Bt1, Bt2)
Paralithic material - the boundary at 89 centimeters (C)