LOCATION WALKERMINE CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, mesic Lithic Dystroxerepts
TYPICAL PEDON: Walkermine very gravelly loam, on a west facing 68 percent slope under a cover of canyon live oak, California black oak, bigleaf maple, with some white fir, sugar pine, Douglas-fir, ponderosa pine and incense cedar at an elevation of 4500 feet, (1372 m). When described on 10/15/99 the soil was slightly moist throughout. (Colors are for dry soil unless otherwise noted).
Oi--0 to 1 inch, (0 to 3 cm); slightly decomposed plant material; abrupt smooth boundary.
A--1 to 3 inches, (3 to 8 cm); light yellowish brown (10YR 6/4) very gravelly loam, brown (7.5YR 4/2) moist; 22 percent clay; moderate fine granular structure; slightly hard, friable, nonsticky, slightly plastic; common very fine and fine roots; many very fine and fine and common medium vesicular and tubular pores; 15 percent cobbles and 45 percent gravel; slightly acid, pH 6.5 by Hellige-Truog; NaF pH 9.0; clear smooth boundary. (2 to 3 inches, (5 to 8 cm) thick)
Bt--3 to 12 inches, (8 to 30 cm); light brown (7.5YR 6/4) very gravelly loam, brown (7.5YR 4/4) moist; 23 percent clay; moderate fine and medium subangular blocky parting to moderate fine granular structure; moderately hard, friable, nonsticky, slightly plastic; common fine and medium roots; many very fine and fine and common medium vesicular and tubular pores; 90 percent continuous faint clay bridging between sand grains; 20 percent cobbles and 40 percent gravel; moderately acid, pH 6.0 by Hellige-Truog; NaF pH 9.2; abrupt smooth boundary. (2 to 18 inches, (5 to 46 cm) thick)
R--12 inches, (30 cm); indurated metavolcanic bedrock.
TYPE LOCATION: Butte County, California, about 2.85 miles east of Lomo, approximately 1320 feet north and 900 feet west of the southeast corner of Section 7, Township 25 N., Range 4 E., 40 degrees, 2 minutes, 6 seconds North latitude and 121 degrees, 33 minutes, 51 seconds West longitude, NAD83 - U.S.G.S Quad: Butte Meadows, California.
RANGE IN CHARACTERISTICS: Depth to lithic bedrock is 4 to 20 inches, (10 to 51 cm). The mean annual soil temperature is 47 to 57 degrees F, (8 to 14 degrees C). The particle-size control section averages 15 to 27 percent clay and 35 to 80 percent rock fragments, mostly gravel. Mineralogy is mixed. Rock fragments on the surface range from 15 to 75 percent gravel, 0 to 30 percent cobbles, 0 to 30 percent stones and 0 to 30 percent boulders.
The A horizon dry color is 10YR 6/2, 6/3, 6/4, 7/3, 7.5YR 5/4, 6/3 or 6/4. Moist color is 7.5YR 3/3, 4/2, 4/3, 4/4, 4/6, 10YR 4/2 or 4/3. Texture is gravelly loam, very gravelly loam, gravelly sandy loam, very gravelly sandy loam, extremely gravelly sandy loam or very gravelly fine sandy loam. Clay content ranges from 12 to 26 percent. Rock fragments range from 20 to 60 percent gravel, 0 to 20 percent cobbles, 0 to 20 percent stones and 0 to 20 percent boulders. Reaction ranges from slightly acid to neutral.
The Bt horizon dry color is 7.5YR 5/4, 6/4, 6/6, 7/4, 10YR 7/2, 7/3 or 7/4. Moist color is 7.5YR 4/3, 4/4, 4/6, 5/4, 5/6, 10YR 4/2, 4/3, 4/4 or 5/4. Texture is very gravelly loam, extremely gravelly loam, very gravelly sandy loam, extremely gravelly sandy loam, extremely cobbly sandy loam, or very gravelly sandy clay loam. Clay content ranges from 12 to 26 percent. Rock fragments range from 25 to 70 percent gravel, 0 to 40 percent cobbles, 0 to 20 percent stones and 0 to 20 percent boulders. Reaction ranges from moderately acid to neutral.
COMPETING SERIES: This is the Goulding series. Goulding soils have a moisture control section that is dry for 130 to 150 days and the mean annual soil temperature is 54 to 59 degrees F (12 to 15 degrees C).
GEOGRAPHIC SETTING: Walkermine soils are on ridge tops and side slopes on metamorphic Sierra Nevada mountains. Slopes range from 3 to 110 percent. These soils formed in residuum and colluvium weathered from metavolcanic and metasedimentary rocks. Elevation is 1900 to 5280 feet, (579 to 1609 m). Mean annual precipitation is 67 to 76 inches, (1702 to 1930 mm). The mean annual temperature is 49 to 54 degrees F, (9 to 12 degrees C). Frost free season is 100 to 175 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bottlehill and Logtrain soils. Bottlehill soils are moderately deep. Logtrain soils are deep.
DRAINAGE AND PERMEABILITY: Well drained; very high runoff; moderate to moderately rapid saturated hydraulic conductivity.
USE AND VEGETATION: This soil is used for watershed, wildlife habitat and timber production. Vegetation is canyon live oak, California black oak, Douglas-fir, ponderosa pine, white fir, incense cedar, sugar pine, tanoak, greenleaf manzanita, Sierra chinquapin, deerbrush, broadleaf starflower, big leaf maple and prostrate ceanothus.
DISTRIBUTION AND EXTENT: Butte County, California and occurs in the M261EF (Metamorphic Foothills) subsection of the M261E (Sierra Nevada) section. MLRA 22A - Sierra Nevada Range. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California 2005. Source of name from Walker Mine in the Secret Creek drainage, Stirling City quad.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - zone from 1 to 3 in, (3 to 8 cm) (A)
Cambic horizon - zone from 3 to 12 in, (8 to 30 cm) (Bt)
Lithic contact - 12 inches, (30 cm)
Particle-size control section - zone from 1 to 12 in. (3 to 30 cm)
The soil moisture control section - zone at 12 inches, (30 cm) is dry in all parts from about mid June to October (about 120 days).