LOCATION LOGTRAIN CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, mesic Typic Haploxerults
TYPICAL PEDON: Logtrain gravelly loam, on a southwest facing 80 percent slope under a cover of incense cedar, Douglas-fir, ponderosa pine, canyon live oak, tanoak, and bigleaf maple at an elevation of 2720 feet, (829 m). When described on 7/27/1999 the soil was dry throughout. (Colors are for dry soil unless otherwise noted).
Oi--0 to 1 inches, (0 to 3 cm); slightly decomposed plant material; abrupt smooth boundary.
A--1 to 3 inches, (3 to 8 cm); pale yellow (2.5Y 7/3) gravelly loam, light olive brown (2.5Y 5/3) moist; 20 percent clay; weak fine and medium subangular blocky parting to moderate fine and medium granular structure; moderately hard, very friable, slightly sticky, slightly plastic; many very fine and fine roots; many very fine, fine and medium irregular and tubular pores; 30 percent gravel; moderately acid, pH 6.0 by Hellige-Truog; clear smooth boundary. (2 to 5 inches, (5 to 13 cm) thick)
Bt1--3 to 9 inches, (8 to 23 cm); pale yellow (2.5Y 7/3) very gravelly loam, light olive brown (2.5Y 5/3) moist; 22 percent clay; moderate fine and medium subangular blocky structure; moderately hard, very friable, slightly sticky, slightly plastic; common very fine, fine, medium and coarse roots; many very fine, fine and medium tubular pores; 60 percent continuous faint clay films; 10 percent cobbles and 25 percent gravel; moderately acid, pH 6.0 by Hellige-Truog; gradual smooth boundary.
Bt2--9 to 21 inches, (23 to 53 cm); pale yellow (2.5Y 7/4) very gravelly loam, light olive brown (2.5Y 5/4) moist; 25 percent clay; moderate fine and medium subangular blocky structure; very hard, very friable, slightly sticky, slightly plastic; common very fine, fine and medium roots and few coarse roots; many very fine, fine and medium tubular pores; 80 percent continuous faint clay films; 5 percent cobbles and 30 percent gravel; strongly acid, pH 5.5 by Hellige-Truog; gradual smooth boundary.
Bt3--21 to 38 inches, (53 to 97 cm); very pale brown (10YR 7/4) very cobbly loam, yellowish brown (10YR 5/4) moist; 26 percent clay; moderate fine and medium subangular blocky structure; moderately hard, very friable, slightly sticky, slightly plastic; many very fine, fine and medium roots and few coarse roots; many very fine, fine and medium tubular pores; 80 percent continuous faint clay films; 15 percent gravel and 25 percent cobbles; very strongly acid, pH 5.0 by Hellige-Truog; gradual smooth boundary.
Bt4--38 to 54 inches, (97 to 137 cm); very pale brown (10YR 7/3) extremely gravelly loam, light yellowish brown (10YR 6/4) moist; 23 percent clay; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; common very fine, fine and medium roots; many very fine, fine and medium tubular pores; 60 percent continuous faint clay films; 20 percent stones, 20 percent cobbles, and 30 percent gravel; very strongly acid, pH 5.0 by Hellige- Truog; gradual smooth boundary. (Combined thickness of the Bt horizon is 34 to 57 inches, (86 to 145 cm) thick).
R--54 inches, (137 cm); strongly cemented metavolcanic bedrock; very strongly acid, pH 5.0 by Hellige-Truog.
TYPE LOCATION: Butte County, California, about 0.87 miles northeast of Robley Point, approximately 125 feet south and 1950 feet west of the northeast corner of Section 10, Township 23 N., Range 4 E., 39 degrees, 52 minutes, 21 seconds North latitude and 121 degrees, 30 minutes, 27 seconds West longitude, NAD83 - U.S.G.S Quad: Paradise East, California.
RANGE IN CHARACTERISTICS: Depth to lithic bedrock is 40 to 60 inches, (102 to 152 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 85 percent rock fragments, mostly gravel. Mineralogy is mixed. Rock fragments on the surface range from 0 to 50 percent gravel, 0 to 30 percent cobbles, 0 to 20 percent stones and 0 to 10 percent boulders.
The A horizon dry color is 7.5YR 6/3, 6/4, 10YR 6/2, 6/3, 6/4, 7/4, 2.5Y 6/3 or 7/3. Moist color is 7.5YR 3/2, 4/2, 4/3, 10YR 3/2, 4/2, 4/3, 2.5Y 4/3 or 5/3. Texture is gravelly loam, very gravelly loam, gravelly sandy loam, very gravelly sandy loam or extremely gravelly sandy loam. Clay content ranges from 10 to 22 percent. Rock fragments range from 25 to 65 percent gravel, 0 to 10 percent cobbles and 0 to 5 percent stones. Reaction ranges from slightly acid to very strongly acid.
The Bt horizon dry color is 7.5YR 6/3, 6/4, 6/6, 7/3, 7/4, 10YR 5/4, 6/4, 6/6, 7/3, 7/4, 8/2, 8/3, 2.5Y 7/3 or 7/4. Moist color is 7.5YR 3/3, 4/2, 4/3, 4/4, 4/6, 5/4, 10YR 4/4, 4/6, 5/3, 5/4, 6/4, 6/6, 2.5Y 5/3, 5/4 or 6/4. Texture is very gravelly loam, extremely gravelly loam, very cobbly loam, gravelly sandy loam, very gravelly sandy loam, extremely gravelly sandy loam, very cobbly sandy loam, extremely cobbly sandy loam, very stony sandy loam or gravelly sandy clay loam. Clay content ranges from 12 to 27 percent. Rock fragments range from 15 to 80 percent gravel, 0 to 40 percent cobbles, and 0 to 40 percent stones. Reaction ranges from slightly acid to extremely acid.
COMPETING SERIES: This is the Honeydew, series. Honeydew soils are moderately deep and have 27 to 35 percent clay in the Bt horizon.
GEOGRAPHIC SETTING: Logtrain soils are on ridge tops and side slopes on metamorphic Sierra Nevada mountains. Slopes range from 3 to 110 percent. These soils formed in colluvium and residuum weathered from metavolcanic and metasedimentary rocks. Elevation is 1900 to 5200 feet, (579 to 1585 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 Walkermine soils. Bottlehill soils are moderately deep. Walkermine soils are shallow.
DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; moderate to moderately rapid saturated hydraulic conductivity in the A horizon and moderately slow to moderately rapid in the Bt horizon.
USE AND VEGETATION: This soil is used for timber production, wildlife habitat and watershed. Vegetation is Douglas-fir, ponderosa pine, California black oak, white fir, sugar pine, tanoak, canyon live oak, incense cedar, bigleaf maple, dogwood, greenleaf manzanita, Sierra chinquapin, prostrate ceanothus, deerbrush, California hazel.
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 is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Particle-size control section - zone from 9 to 38 in, (23 to 97 cm)
Ochric epipedon - zone from 1 to 3 in, (3 to 8 cm) (A)
Argillic horizon - zone from 9 to 38 in, (23 to 97 cm) (Bt1, Bt2, Bt3)
Lithic contact - 54 inches, 137 cm
Mineralogy and soil chemistry assumed from geographically associated Bottlehill soil.
The soil moisture control section - zone from 10 to 27 inches, (25 to 69 cm) is dry in all parts from about June to October (about 150 days).