LOCATION RETSONGULCH CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic, mesic Typic Haploxerults
TYPICAL PEDON: Retsongulch very gravelly sandy loam, on an east facing 75 percent slope under a cover of Douglas-fir, tanoak, ponderosa pine, canyon live oak, California black oak, sugar pine, incense cedar, and white fir at an elevation of 3300 feet, (1006 m). When described on 8/10/99 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); pink (7.5YR 7/3) very gravelly sandy loam, brown (7.5YR 4/3) moist; 18 percent clay; moderate fine granular structure; soft, very friable, slightly sticky, nonplastic; many very fine and fine roots and few medium roots; many very fine, fine and medium irregular and tubular pores; 5 percent cobbles and 30 percent gravel; moderately acid, pH 5.8 by Hellige-Truog; NaF pH 9.7; clear smooth boundary. (2 to 3 inches, (5 to 8 cm) thick)
Bt1--3 to 12 inches, (8 to 30 cm); pink (7.5YR 7/4) very gravelly sandy clay loam, brown (7.5YR 5/4) moist; 23 percent clay; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; many very fine, fine and medium roots and few coarse roots; many very fine and fine and common medium tubular pores; 60 percent continuous distinct clay films; 5 percent stones, 10 percent cobbles, and 25 percent gravel; very strongly acid, pH 4.8 by Hellige-Truog; NaF pH 9.7; gradual smooth boundary.
Bt2--12 to 21 inches, (30 to 53 cm); pink (7.5YR 7/4) extremely gravelly sandy clay loam, yellowish brown (10YR 5/6) moist; 20 percent clay; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; many very fine, fine, medium and coarse roots; many very fine, fine and medium tubular pores; 50 percent discontinuous faint clay films; 10 percent stones, 20 percent cobbles, and 35 percent gravel; very strongly acid, pH 4.8 by Hellige-Truog; NaF pH 9.5; gradual smooth boundary.
Bt3--21 to 30 inches, (53 to 76 cm); very pale brown (10YR 8/4) extremely gravelly sandy loam, light yellowish brown (10YR 6/4) moist; 12 percent clay; weak fine subangular blocky structure; loose, nonsticky, nonplastic; many very fine, fine, medium and coarse roots; many very fine, fine and medium tubular pores; 30 percent discontinuous faint clay films; 10 percent stones, 25 percent cobbles, and 35 percent gravel; very strongly acid, pH 4.8 by Hellige-Truog; NaF pH 9.5; clear wavy boundary. (Combined thickness of the Bt horizon is 17 to 38 inches, (43 to 97 cm) thick).
R--30 inches, (76 cm); strongly cemented metadiorite bedrock.
TYPE LOCATION: Butte County, California, about 0.7 miles east of Stirling City, approximately 1275 feet south and 1500 feet east of the northwest corner of Section 27, Township 24 N., Range 4 E., 39 degrees, 54 minutes, 43 seconds North latitude and 121 degrees, 31 minutes, 1 seconds West longitude, NAD83 - U.S.G.S Quad: Stirling City, California.
RANGE IN CHARACTERISTICS: Depth to lithic bedrock is 20 to 40 inches, (51 to 102 cm). The mean annual soil temperature is 47 to 55 degrees F, (8 to 13 degrees C). The particle-size control section averages 12 to 27 percent clay and 35 to 60 percent rock fragments, mostly gravel. Mineralogy is isotic. Rock fragments on the surface range from 15 to 80 percent gravel, 0 to 15 percent cobbles, 0 to 10 percent stones and 0 to 10 percent boulders.
The A horizon dry color is 7.5YR 6/3, 6/4, 7/3, 10YR 5/3, 5/4 or 6/3. Moist color is 7.5YR 4/2, 4/3, 4/4, 10YR 3/2, 3/3 or 4/3. Texture is gravelly sandy loam, very gravelly sandy loam, loam, gravelly loam or very gravelly loam. Clay content ranges from 10 to 22 percent. Rock fragments range from 5 to 40 percent gravel, 0 to 10 percent cobbles, 0 to 5 percent stones and 0 to 5 percent boulders. Reaction ranges from moderately acid to slightly acid.
The Bt horizon dry color is 7.5YR 5/6, 6/4, 6/6, 7/4, 7/6, 10YR 6/4, 7/3, 7/4 or 8/4. Moist color is 7.5YR 4/4, 5/4, 5/6, 10YR 4/3, 4/4, 5/4, 5/6 or 6/4. Texture is gravelly sandy loam, very gravelly sandy loam, extremely gravelly sandy loam, gravelly loam, very gravelly loam, very gravelly sandy clay loam, or extremely gravelly sandy clay loam. Clay content ranges from 12 to 26 percent. Rock fragments range from 25 to 50 percent gravel, 5 to 35 percent cobbles, 0 to 15 percent stones and 0 to 10 percent boulders. Reaction ranges from very strongly acid to slightly acid.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Retsongulch soils are on canyon side slopes in metamorphic Sierra Nevada mountains. Slopes range from 50 to 100 percent. These soils formed in colluvium and residuum weathered from coarse grained metamorphic rocks, mainly metadiorite. Elevation is 2000 to 5200 feet, (610 to 1585 m). Mean annual precipitation is 70 to 78 inches, (1778 to 1981 mm). The mean annual temperature is 50 to 54 degrees F, (10 to 12 degrees C). Frost free season is 110 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Obstruction, Obskel and Flumewall soils. Obstruction soils are very deep and fine-loamy. Obskel soils are deep. Flumewall soils are shallow.
DRAINAGE AND PERMEABILITY: Well drained; high runoff; moderate to moderately rapid saturated hydraulic conductivity.
USE AND VEGETATION: This soil is used for timber production, wildlife habitat and watershed. Vegetation is Douglas-fir, canyon live oak, tanoak, ponderosa pine, California black oak, sugar pine, incense cedar and white fir.
DISTRIBUTION AND EXTENT: Butte County, California and occur 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 Retson Gulch on the Stirling City 7.5 minute quadrangle.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - zone from 1 to 3 in, (3 to 8 cm) (A)
Argillic horizon - zone from 3 to 12 in, (8 to 30 cm) (Bt1)
Lithic contact - 30 in, (76 cm)
Mineralogy assumed based on data from geographically associated Obstruction series.
Particle-size control section - zone from 3 to 12 in, (8 to 30 cm)
The soil moisture control section - zone from 12 to 30 inches, (30 to 76 cm) is dry in all parts from about June to October (about 150 days).