LOCATION LEWISFLAT CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, semiactive, mesic Andic Haploxerults
TYPICAL PEDON: Lewisflat loam, on a northeast facing 3 percent slope under mixed conifers at an elevation of 3675 feet, (1120 m). When described on 11/1/95 the soil was slightly moist throughout. (Colors are for dry soil unless otherwise noted).
Oi--0 to 3 inches, (0 to 8 cm); needles, cones and twig litter. (1 to 6 inches, (2.5 to 15 cm) thick)
A1--3 to 5 inches, (8 to 13 cm); brown (10YR 4/3) loam, brown (7.5YR 4/3) moist; 14 percent clay; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine roots; few very fine tubular pores; noneffervescent; 10 percent rounded gravel; strongly acid, pH 5.2 by pH meter 1:1 water; NaF pH 10.8; abrupt smooth boundary.
A2--5 to 9 inches, (13 to 23 cm); strong brown (7.5YR 5/6) loam, brown (7.5YR 4/4) moist; 17 percent clay; moderate medium subangular blocky structure; slightly hard, firm, nonsticky and slightly plastic; common very fine and fine roots; common very fine tubular pores; noneffervescent; 5 percent rounded gravel; strongly acid, pH 5.5 by pH meter 1:1 water; NaF pH 10.2; abrupt smooth boundary. (Combined thickness of the A horizon is 6 to 20 inches, (15 to 51 cm) thick).
Bt1--9 to 18 inches, (23 to 46 cm); strong brown (7.5YR 5/6) loam, strong brown (7.5YR 5/6) moist; 25 percent clay; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and moderately plastic; common very fine and fine roots; common very fine tubular pores; few clay films on faces of peds and in pores; noneffervescent; 5 percent rounded gravel; strongly acid, pH 5.4 by pH meter 1:1 water; NaF pH 9.7; clear smooth boundary. (8 to 10 inches, (20 to 25 cm) thick)
2Bt2--18 to 33 inches, (46 to 84 cm); reddish yellow (7.5YR 6/6) loam, strong brown (7.5YR 5/6) moist; 24 percent clay; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; common very fine and fine roots and few medium and coarse; common very fine tubular pores; common clay films on faces of peds and in pores; noneffervescent; 2 percent subrounded gravel; strongly acid, pH 5.3 by pH meter 1:1 water; NaF pH 9.4; clear smooth boundary.
2Bt3--33 to 49 inches, (84 to 125 cm); reddish yellow (7.5YR 6/6) loam, strong brown (7.5YR 5/6) moist; 19 percent clay; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; common fine and medium roots and few coarse; few very fine tubular pores; few clay films on faces of peds and in pores; noneffervescent; strongly acid, pH 5.1 by pH meter 1:1 water; NaF pH 9.5; clear smooth boundary. (Combined thickness of the 2Bt horizon is 10 to 46 inches, (25 to 117 cm) thick).
2BCt1--49 to 65 inches, (125 to 165 cm); reddish yellow (7.5YR 7/6) loam, strong brown (7.5YR 5/6) moist; 12 percent clay; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common fine and medium, and few coarse roots; few very fine tubular pores; few clay films on faces of peds and in pores; noneffervescent; strongly acid, pH 5.1 by pH meter 1:1 water; gradual smooth boundary.
2BCt2--65 to 75 inches, (165 to 190 cm); reddish yellow (7.5YR 7/6) loam, reddish yellow (7.5YR 6/6) moist; 12 percent clay; weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; few fine and medium roots; few very fine tubular pores; few clay films in root channels and pores; very strongly acid, pH 5.0 by pH meter 1:1 water; (Combined thickness of the 2BCt horizon is 15 to 68 inches, (38 to 173 cm) or more).
TYPE LOCATION: Butte County, California; about 1.1 miles north of Strawberry Valley, approximately 1400 feet east and 2000 feet south of the northwest corner of Section 20, Township 20 N., Range 8 E., 39 degrees, 34 minutes, 47.5 seconds North latitude and 121 degrees, 6 minutes, 37.5 seconds West longitude, NAD27. U.S.G.S. Quad: Strawberry Valley, California.
RANGE IN CHARACTERISTICS: Depth to paralithic bedrock (quartz diorite) is greater than 60 inches, (152 cm). The mean annual soil temperature is 52 to 56 degrees F, (11 to 13 degrees C). The soil moisture control section is dry in all parts from about June 1 to about October 1 (about 90 to 110 days) The particle-size control section averages 18 to 27 percent clay and 0 to 20 percent rock fragments, mostly gravel. Mineralogy is mixed. Organic matter ranges from 8 to 10 percent to a depth of 2 inches, (5 cm), 1 to 2 percent from 2 to 15 inches, (5 to 38 cm), and less than 0.6 percent from 15 to 72 inches, (38 to 183 cm). Base saturation by sum of cations ranges from 9 to 32 percent in the argillic horizon. Acid Oxalate extractable Al plus 1/2 Fe ranges from 1 to 2 to a depth of 18 inches, (46 cm). Rock fragments on the surface range from 0 to 10 percent gravel. Some pedons have 2Bw or 2C horizons below the argillic horizon.
The A horizon dry color is 7.5YR 4/2, 5/4, 5/6, 6/4, 6/6, 10YR 4/3 or 6/3. Moist color is 7.5YR 3/2, 3/3, 3/4, 4/3, 4/4, 4/6 or 10YR 5/4. Texture is dominantly loam, but in some pedons is sandy loam or coarse sandy loam. Clay content ranges from 5 to 18 percent. Rock fragments range from 5 to 10 percent gravel. NaF pH ranges from 10.0 to 11.5. Reaction ranges from strongly acid to slightly acid.
The Bt horizon dry color is 7.5YR 5/6, 6/4, 6/6, 7/4, 7/6 or 5YR 5/6. Moist color is 7.5YR 4/4, 4/6, 5/4, 5/6, 5/8, 6/8, 5YR 4/4, 5/6, 5/8, 10YR 5/4 or 5/6. Texture is loam, gravelly loam, sandy clay loam or gravelly sandy clay loam. Clay content ranges from 18 to 27 percent. Rock fragments range from 0 to 20 percent gravel. NaF pH ranges from 9.7 to 10.0. Reaction ranges from strongly acid to moderately acid.
The 2Bt horizon dry color is 7.5YR 5/6, 6/4, 6/6, 7/4, 7/6 or 5YR 5/6. Moist color is 7.5YR 4/4, 4/6, 5/4, 5/6, 5/8, 6/8, 5YR 4/4, 5/6, 5/8, 10YR 5/4 or 5/6. Texture is loam, gravelly loam, sandy clay loam or gravelly sandy clay loam. Clay content ranges from 18 to 27 percent. Rock fragments range from 0 to 20 percent gravel. NaF pH ranges from 9.4 to 9.0. Reaction ranges from strongly acid to moderately acid.
The 2BCt horizon dry color is 7.5YR 6/6 or 7/6. Moist color is 7.5YR 5/6, 6/6, 5/8, 6/8, 10YR 5/6, 6/6 or 7/6. Texture is loam, gravelly loam, sandy clay loam, sandy loam, gravelly sandy loam or fine sandy loam. Clay content ranges from 8 to 27 percent. Rock fragments range from 0 to 20 percent gravel. NaF pH ranges from 9.0 to 9.5. Reaction ranges from very strongly acid to moderately acid.
The 2Bw horizon, when present has dry color of 7.5YR 6/6 or 7/6. Moist color is 7.5YR 5/6, 6/6, 5/8, 6/8, 10YR 5/6, 6/6 or 7/6. Texture is loam or sandy loam. Clay content ranges from 8 to 18 percent. Rock fragments range from 0 to 15 percent gravel. NaF pH ranges from 9.0 to 9.5. Reaction ranges from very strongly acid to moderately acid.
The 2C horizon, when present has dry color of 7.5YR 6/6 or 7/6. Moist color is 7.5YR 5/6, 6/6, 5/8, 6/8, 10YR 5/6, 6/6 or 7/6. Texture is loam or sandy loam. Clay content ranges from 8 to 18 percent. Rock fragments range from 0 to 15 percent gravel. NaF pH ranges from 9.0 to 9.5. Reaction ranges from very strongly acid to moderately acid.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Lewisflat soils are on side slopes on granitic Sierra Nevada mountains. Slopes range from 2 to 50 percent. These soils formed in tephra over residuum and colluvium weathered from quartz diorite. Elevation is 3100 to 4600 feet, (945 to 1402 m). Mean annual precipitation is 70 to 80 inches, (1778 to 2032 mm). The mean annual temperature is 50 to 54 degrees F, (10 to 12 degrees C). Frost free season is 110 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Billscabin and Bonneyridge soils. Billscabin soils are loamy-skeletal, have a cambic horizon and have less than 18 percent clay in the particle-size control section. Bonneyridge soils are coarse-loamy and have a cambic horizon.
DRAINAGE AND PERMEABILITY: Well drained; low to high runoff; moderate to moderately rapid saturated hydraulic conductivity in the A1 horizon, moderate in the A2 and Bt horizons and moderate to moderately rapid in the BCt horizons.
USE AND VEGETATION: This soil is used for timber production, wildlife habitat and watershed. Vegetation is sugar pine, white fir, Douglas-fir, ponderosa pine, incense cedar, California black oak with an understory of deerbrush, dogwood, brackenfern, broadleaf starflower, iris, common snowberry, California wild grape, whitevein shinleaf, woodland strawberry and princes pine. Tanoak and Pacfic madrone are found below an elevation of 4000 feet, (1219 m).
DISTRIBUTION AND EXTENT: Butte and Plumas Counties, California and occurs on the Granitic and Metamorphic Hills subsection of the Sierra Nevada section. MLRA 22A - Sierra Nevada Range. The soils are not extensive. Occur on the Lumpkin and Cascade plutons.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California 2005. Source of name from Lewis Flat on the Strawberry Valley Quad.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - zone from 3 to 9 inches, (8 to 23 cm) (A1, A2).
Argillic horizon - zone from 9 to 49 inches, (23 to 125 cm) (Bt1, 2Bt2, 2Bt3, 2Bt4).
Soil moisture control section - zone from 8 to 21 inches, (20 to 53 cm).
Particle-size control section - zone from 9 to 29 inches, (23 to 74 cm).
ADDITIONAL DATA: Reference samples from lab pedon number: 96P0142, NSSL Lincoln, NE.