LOCATION LOAFERCREEK CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Ultic Haploxeralfs
TYPICAL PEDON: Loafercreek gravelly loam, on a northwest facing 18 percent slope under a cover of interior live oak, blue oak, foothill pine, whiteleaf manzanita, toyon, buckbrush, Pacific poison oak, honeysuckle, squirreltail, hedgehog dogtail, and rattlesnake brome at an elevation of 1197 feet, (365 m). When described on 8/4/1999, the soil was dry throughout. (Colors are for dry soil unless otherwise noted).
Oi--0 to 0.5 inches, (0 to 1 cm); leaves, needles, duff
A--0.5 to 2 inches, (1 to 5 cm); reddish brown (5YR 5/4) gravelly loam, reddish brown (5YR 4/3) moist; 17 percent clay; moderate fine subangular blocky parting to moderate fine granular structure; hard, friable, nonsticky, slightly plastic; common very fine roots; many very fine irregular pores; 20 percent subangular metavolcanic gravel; moderately acid, pH 6.1 by Hellige-Truog; abrupt wavy boundary. (1 to 3 inches, (3 to 8 cm) thick)
BAt--2 to 6 inches, (5 to 15 cm); reddish brown (5YR 5/4) gravelly loam, reddish brown (5YR 4/3) moist; 17 percent clay; moderate medium subangular blocky structure; hard, friable, nonsticky, slightly plastic; few fine roots and common very fine roots; common very fine tubular pores; 20 percent discontinuous faint clay films on faces of peds; 25 percent subangular metavolcanic gravel; slightly acid, pH 6.2 by Hellige-Truog; clear smooth boundary. (3 to 7 inches, (8 to 18 cm) thick)
Bt1--6 to 12 inches, (15 to 30 cm); yellowish red (5YR 5/6) loam, dark reddish brown (5YR 3/4) moist; 20 percent clay; moderate medium subangular blocky structure; hard, friable, nonsticky, slightly plastic; common fine roots and few medium and coarse roots; common very fine tubular pores; 30 percent discontinuous distinct clay films on faces of peds and on surfaces along pores; 10 percent subangular metavolcanic gravel; slightly acid, pH 6.2 by Hellige-Truog; clear wavy boundary. (5 to 11 inches, (13 to 28 cm) thick)
Bt2--12 to 23 inches, (30 to 58 cm); yellowish red (5YR 5/6) gravelly loam, yellowish red (5YR 4/6) moist; 24 percent clay; moderate fine subangular blocky structure; hard, friable, slightly sticky, moderately plastic; few fine, medium and coarse roots; many very fine tubular pores; 30 percent discontinuous distinct clay films on faces of peds and on surfaces along pores; 5 percent subangular metavolcanic cobbles, and 20 percent subangular metavolcanic gravel; slightly acid, pH 6.3 by Hellige-Truog; gradual wavy boundary. (3 to 11 inches, (8 to 28 cm) thick)
Bt3--23 to 31 inches, (58 to 79 cm); yellowish red (5YR 5/6) gravelly silt loam, yellowish red (5YR 4/6) moist; 22 percent clay; moderate fine subangular blocky structure; hard, firm, slightly sticky, moderately plastic; common fine roots and few medium and coarse roots; common very fine tubular pores; 30 percent discontinuous distinct clay films on faces of peds and on surfaces along pores; 20 percent subangular metavolcanic gravel; slightly acid, pH 6.2 by Hellige-Truog; abrupt wavy boundary. (5 to 8 inches, (13 to 20 cm) thick)
Crt--31 to 42 inches, (79 to 107 cm); weathered moderately cemented greenschist; few fine roots; 60 percent continuous prominent clay films on rock fragments; abrupt wavy boundary. (5 to 11 inches, (13 to 28) thick)
R--42 inches, (107 cm); indurated greenschist.
TYPE LOCATION: Butte County, California; about 4.5 miles northeast of Wyandotte, California, approximately 2450 feet south and 1400 feet east of the northwest corner of Section 8, Township 19 N., Range 5 E., 39 degrees, 31 minutes, 08.28 seconds North latitude and 121 degrees, 26 minutes, 28.49 seconds West longitude: NAD83-U.S.G.S. Quad: Oroville Dam, California.
RANGE IN CHARACTERISTICS: Depth to paralithic bedrock is 20 to 40 inches, (51 to 102 cm). The mean annual soil temperature is 59 to 65 degrees F, (15 to 18 degrees C). The soil moisture control section is dry in all parts from about June 1 to October 15 (about 150 days). The particle-size control section averages 24 to 33 percent clay and 5 to 33 percent rock fragments, mostly gravel. Mineralogy is mixed. Rock fragments on the surface range from 0 to 25 percent gravel, 0 to 10 percent cobbles and 0 to 10 percent stones. Surface and subsoil horizons have 40 to 50 percent silt.
The A horizon dry color is 7.5YR 4/6, 5/4, 5/6, 5YR 4/4, 4/6 or 5/4. Moist color is 7.5YR 3/4, 4/4, 5YR 3/4 or 4/3. Texture is loam, gravelly loam, with high silt content, or silt loam. Clay content ranges from 14 to 22 percent. Rock fragments range from 3 to 20 percent gravel. Base saturation by sum of cations ranges from 60 to 70 percent. Organic matter ranges from 5 to 10 percent. Reaction ranges from strongly acid to neutral.
The BAt horizon dry color is 7.5YR 4/6, 5/6, 5YR 4/6, 5/4, 5/6 or 5/8. Moist color is 7.5YR 3/4, 4/4, 5YR 4/3, 4/4, 4/6 or 2.5YR 4/4. Texture is loam, gravelly loam, with high silt content, or silt loam. Clay content ranges from 15 to 24 percent. Rock fragments range from 3 to 30 percent gravel and 0 to 5 percent cobbles. Base saturation by sum of cations ranges from 65 to 73 percent. Organic matter ranges from 1 to 4 percent. Reaction ranges from strongly acid to neutral.
The upper Bt horizon dry color is 7.5YR 5/6, 5YR 4/6, 5/6 or 2.5YR 4/6. Moist color is 5YR 3/4, 4/4, 4/6 or 2.5YR 3/6. Texture is loam, gravelly loam, clay loam or gravelly clay loam, with high silt content. Clay content ranges from 18 to 30 percent. Rock fragments range from 5 to 25 percent gravel and 0 to 5 percent cobbles. Base saturation by sum of cations ranges from 65 to 73 percent. Organic matter ranges from 0.5 to 2.0 percent. Reaction ranges from moderately acid to neutral.
The lower Bt horizon dry color is 7.5YR 4/6, 5/6, 5YR 4/6 or 5/6. Moist color is 7.5YR 4/4, 4/6, 5YR 4/3, 4/4, 4/6, 2.5YR 3/6 or 4/6. Texture is loam, gravelly loam, clay loam or gravelly clay loam. Clay content ranges from 18 to 30 percent. Rock fragments range from 5 to 30 percent gravel and 0 to 10 percent cobbles. Base saturation by sum of cations ranges from 74 to 85 percent. Organic matter ranges from 0.5 to 1.5 percent. Reaction ranges from moderately acid to neutral.
COMPETING SERIES: These are the Bearwallow, Churn, Mounthope, Sommeyflat and Wisheylu series. Bearwallow soils do not have high silt content. Churn soils have a hue of 10YR. Mounthope soils are deep. Sommeyflat soils are very deep. Wisheylu soils have hues of 2.5YR and 7.5YR.
GEOGRAPHIC SETTING: Loafercreek soils are on ridge tops and side slopes on metamorphic Sierra Nevada foothills. Slopes range from 1 to 90 percent. These soils formed in colluvium and residuum weathered from metavolcanic rocks, mainly greenschist. Elevation is 200 to 1600 feet, (61 to 488 m). Mean annual precipitation is 28 to 40 inches, (711 to 1016 mm). The mean annual temperature is 57 to 63 degrees F, (14 to 17 degrees C). Frost free season is 230 to 260 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dunstone and Sobrante soils. Dunstone soils are less than 20 inches, (51 cm) deep to a paralithic contact. Sobrante soils have an A horizon that throughout its upper 5 inches, (13 cm) has a color value, moist, of 3 or less and has 0.7 percent or more organic carbon.
DRAINAGE AND PERMEABILITY: Well drained; high runoff; moderate to moderately rapid saturated hydraulic conductivity in the A and BAt horizons and moderate to moderately slow in the Bt horizon.
USE AND VEGETATION: This soil is used for livestock grazing, home site development, wildlife habitat, watershed and recreation. Vegetation is blue oak, scattered foothill pine, interior live oak, toyon, whiteleaf manzanita, buckbrush, Pacific poison oak, annual grasses and forbs.
DISTRIBUTION AND EXTENT: Butte County, California and occurs in (M261Fb) Lower Foothills Metamorphic Belt subsection of the (M261F) Sierra Nevada Foothills section. MLRA 18 - Sierra Nevada Foothills. The soils are moderately extensive.
MLRA OFFICE RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California 2005. Source of name is from Loafer Creek on the Oroville Dam Quadrangle.
REMARKS: These soils were previously mapped as Aiken clay loam (Ac) in the Soil Survey of Oroville Area, California 1926.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - zone from 0.5 to 2 inches, (1 to 15 cm), (A, BAt)
Argillic horizon - zone from 6 to 31 inches, (15 to 79 cm), (Bt1, Bt2, Bt3)
Particle-size control section - zone from 6 to 26 inches, (15 to 66 cm).
The soil moisture control section - zone from 8 to 25 inches, (20 to 63 cm).
ADDITIONAL DATA: Reference samples from lab pedon number: 01N0266, and reference samples from lab pedon number: 01N0263, NSSL, Lincoln, NE. Additional lab data from #66-04-4X, lab #490, 7/1/1966, University of California-Davis, Soil Morphology Laboratory.