LOCATION MUDWASH CAEstablished Series
TAXONOMIC CLASS: Medial over loamy, mixed over isotic, mesic Alfic Humic Haploxerands
TYPICAL PEDON: Mudwash gravelly medial sandy loam on a southwest facing 7 percent slope under a cover of mixed conifers at an elevation of 4650 feet, (1417 m). When described on 10/7/97 the soil was slightly moist from 4 to 52 inches, (10 to 132 cm) and dry below a depth of 52 inches, (132 cm). Clay percentages are based on apparent field texture. (Colors are for dry soil unless otherwise noted)
Oi--0 to 1 inches, (0 to 2.54 cm); fresh litter.
Oa--1 to 4 inches, (2.54 to 10 cm); decomposed litter. (Combined thickness of the Oi and the Oa horizon is 1 to 4 inches, (2.54 to 10 cm) thick).
A1--4 to 8 inches, (10 to 20 cm); brown (7.5YR 4/2) gravelly medial sandy loam, dark brown (7.5YR 3/2) moist; 10 percent clay; moderate fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine to medium roots; many very fine irregular pores; 15 percent basalt gravel and 5 percent basalt cobbles; strongly acid, pH 5.4 by pH meter 1:1 water; NaF pH 10.5; abrupt smooth boundary.
A2--8 to 13 inches, (20 to 33 cm); brown (7.5YR 4/2) gravelly medial sandy loam, dark brown (7.5YR 3/2) moist; 12 percent clay; weak fine subangular blocky structure; loose, very friable, nonsticky and nonplastic; common coarse and many fine and medium roots; many very fine irregular pores; 20 percent basalt gravel and 5 percent basalt cobbles; strongly acid, pH 5.4 by pH meter 1:1 water; NaF pH 10.5; clear smooth boundary. (Combined thickness of the A horizon is 4 to 20 inches, (10 to 51 cm) thick.)
Bw--13 to 26 inches, (33 to 66 cm); brown (7.5YR 4/3) gravelly medial sandy loam, dark reddish brown (5YR 3/3) moist; 15 percent clay; moderate fine subangular blocky structure; loose, very friable, nonsticky and slightly plastic; common fine to coarse roots; many very fine irregular pores; 25 percent basalt gravel and 5 percent basalt cobbles; strongly acid, pH 5.1 by pH meter 1:1 water; NaF pH 10.0; clear wavy boundary. (6 to 28 inches, (15 to 71 cm) thick)
2Bt1--26 to 35 inches, (66 to 89 cm); grayish brown (10YR 5/2) gravelly loam, dark brown (7.5YR 3/2) moist; 22 percent clay; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine to coarse roots; many very fine tubular pores; few distinct continuous clay films on faces of peds; 20 percent rounded basalt gravel; strongly acid, pH 5.1 by pH meter 1:1 water; NaF pH 9.3; clear smooth boundary.
2Bt2--35 to 52 inches, (89 to 132 cm); brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; 25 percent clay; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots; many very fine tubular pores and common fine tubular pores; common distinct continuous clay films on faces of peds; 20 percent rounded basalt gravel; strongly acid, pH 5.3 by pH meter 1:1 water; NaF pH 9.4 abrupt smooth boundary. (Combined thickness of the 2Bt horizon is 8 to 46 inches, (20 to 117 cm) thick).
2BCt--52 to 72 inches, (132 to 183 cm); brown (10YR 5/3) extremely gravelly loam, dark brown (10YR 3/3) moist; 24 percent clay; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and medium roots; common very fine tubular pores; few distinct continuous clay films on faces of peds; 80 percent rounded basalt gravel; strongly acid, pH 5.4 by pH meter 1:1 water; NaF pH 9.3; gradual smooth boundary. (9 to 54 inches, (23 to 137 cm) thick)
2Cr--72 to 89 inches, (183 to 226 cm); moderately cemented basalt bedrock, few fine roots; white and yellow concretions and manganese stains, no fractures.
TYPE LOCATION: Plumas County, California; about 1.6 miles southeast of Cascade, approximately 450 feet west and 500 feet south of the northeast corner of Section 14, Township 21 N., Range 7 E., 39 degrees, 41 minutes, 9.3 seconds North latitude and 121 degrees, 9 minutes, 21.9 seconds West longitude, NAD83. - U.S.G.S. Quad: Cascade, California.
RANGE IN CHARACTERISTICS: Depth to paralithic bedrock of basalt, mudflow or volcaniclastic materials is greater than 60 inches, (152 cm). The mean annual soil temperature is 47 to 54 degrees F, (8 to 12 degrees C). The soil moisture control section is dry in all parts from about July to about September (about 90 days). The particle-size control section averages 11 to 30 percent clay and 5 to 27 percent rock fragments in the medial part and 23 to 35 percent clay and 5 to 20 percent rock fragments in the loamy part. Mineralogy is mixed over isotic. Rock fragments on the surface range from 0 to 20 percent gravel and 0 to 25 percent cobbles. Some pedons have a C horizon and or lack a 2BCt horizon.
The A horizon dry color is 10YR 4/2, 4/3, 7.5YR 4/2, 4/3, 4/4, 5YR 4/6, 5/3 or 5/4. Moist color is 10YR 2/1, 2/2, 7.5YR 3/2, 3/3, 5YR 3/2, 3/3 or 3/4. Texture is gravelly medial sandy loam, gravelly medial loam, medial sandy loam or medial loam. Organic matter ranges from 5 to 10 percent. Base saturation by sum of cations ranges from 15 to 20 percent. Clay content ranges from 8 to 18 percent. Rock fragments range from 5 to 20 percent gravel and 5 to 10 percent cobbles. NaF pH ranges from 10.0 to 11.5. Acid Oxalate extractable Al plus 1/2 Fe ranges from 2.2 to 2.5. P retention ranges from 90 to 92. Reaction ranges from slightly acid to strongly acid.
The Bw horizon dry color is 7.5YR 4/3, 5/3, 5YR 4/6 or 5/4. Moist color is 7.5YR 3/2, 3/4, 4/2, 5YR 3/3, 4/3 or 4/4. Texture is gravelly medial sandy loam, gravelly medial loam, medial sandy loam or medial loam. Organic matter ranges from 5 to 9 percent. Base saturation by sum of cations ranges from 10 to 25 percent. Clay content ranges from 12 to 22 percent. Rock fragments range from 5 to 25 percent gravel and 0 to 5 percent cobbles. NaF pH ranges from 10.5 to 11. Acid Oxalate extractable Al plus 1/2 Fe ranges from 2.0 to 2.5. P retention ranges from 85 to 90. Reaction ranges from slightly acid to very strongly acid.
The 2Bt horizon dry color is 10YR 4/3, 5/2, 5/3, 8/4, 7.5YR 4/3, 5/3, 5/4, 5YR 4/4, 4/6 or 2.5YR 4/6. Moist color is 10YR 3/3, 7.5YR 3/2, 3/3, 4/2, 4/3, 4/6, 5YR 3/2, 3/3, 4/3, 4/4, 2.5YR 3/6 or 4/6. Texture is gravelly loam, loam, sandy loam, clay loam, sandy clay loam, silty clay loam, gravelly sandy clay loam or cobbly loam. Organic matter ranges from 0.8 to 5 percent. Base saturation by sum of cations ranges from 50 to 70 percent. Clay content ranges from 18 to 38 percent. Rock fragments range from 0 to 20 percent gravel and 0 to 20 percent cobbles. NaF pH ranges from 9.3 to 11.3. Acid Oxalate extractable Al plus 1/2 Fe ranges from 1.0 to 1.8. P retention ranges from 55 to 70. Reaction ranges from slightly acid to extremely acid.
The 2BCt horizon dry color is 10YR 4/2, 5/3, 6/3, 7.5YR 5/3 or 6/3. Moist color is 10YR 3/1, 3/3, 4/3, 4/4, 5/2, 7.5YR 4/2, 4/3 or 4/4. Texture is extremely gravelly loam, gravelly sandy loam, loam, coarse sandy loam, sandy clay loam or silty clay loam. Organic matter ranges from 0.8 to 1 percent. Base saturation by sum of cations ranges from 50 to 70 percent. Clay content ranges from 15 to 28 percent. Rock fragments range from 5 to 80 percent gravel. NaF pH ranges from 9.3 to 10.5. Acid Oxalate extractable Al plus 1/2 Fe ranges from 0.7 to 1. P retention ranges from 50 to 60. Reaction ranges from moderately acid to extremely acid.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Mudwash soils are on ridge tops and side slopes on basalt ridges on volcanic Sierra Nevada mountains. Slopes range from 0 to 50 percent. These soils formed in tephra deposited over colluvium and residuum weathered from basalt. Elevation is 3200 to 4800 feet, (975 to 1463 m). Mean annual precipitation is 75 to 80 inches, (1905 to 2032 mm). The mean annual temperature is 45 to 52 degrees F, (7 to 11 degrees C). Frost free season is 110 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bonneyridge, Lavatop, Lewisflat, McNair, Powderhouse, Timberisland and Shakeridge soils. Bonneyridge soils are very deep, coarse-loamy, have an ochric epipedon, and are formed from residuum from quartz diorite. Lavatop soils are moderately deep to a lithic contact of basalt, medial-skeletal, and have andic soil properties throughout. Lewisflat soils are very deep, fine-loamy, and formed from residuum from quartz diorite. McNair soils are deep to paralithic contact of volcanic mudflow, medial-skeletal, and have andic soil properties throughout the control section. Powderhouse soils are moderately deep to a paralithic contact of volcanic mudflow, medial-skeletal, and have andic soil properties throughout. Timberisland soils are deep to a lithic contact of basalt, medial-skeletal, and have andic soil properties throughout. Shakeridge soils are very deep, medial-skeletal, and have andic soil properties throughout.
DRAINAGE AND PERMEABILITY: Well drained; low to medium runoff; moderately rapid saturated hydraulic conductivity in the A and Bw horizons and moderate in the 2Bt and 2BCt horizons.
USE AND VEGETATION: This soil is used for timber production, watershed and wildlife habitat. Vegetation is ponderosa pine, incense cedar, white fir, sugar pine, Douglas-fir, California black oak, with an understory of deerbrush, dogwood, snowberry, whitethorn ceanothus, greenleaf manzanita, brackenfern, tanoak, Sierra gooseberry, whiteleaf manzanita, whitevein shinleaf and princes pine.
DISTRIBUTION AND EXTENT: Plumas and Butte Counties, California. MLRA 22A Sierra Nevada Range. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Plumas County, California 2005. Source of name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon - zone from 4 to 26 inches, (10 to 66 cm) (A1, A2, Bw)
Argillic horizon - zone from 26 to 72 inches, (66 to 183 cm) (2Bt1, 2Bt2, 2BCt).
Paralithic contact - the zone from 72 to 89 inches, (183 to 226 cm) (2Cr).
Particle-size control section - zone from 4 to 40 inches, (10 to 102 cm).
The soil moisture control section - zone from 14 to 33 inches, (36 to 84 cm).
Andic soil properties - zone from 4 to 26 inches, (10 to 66 cm).
Bulk density was assumed to be less than 0.9 g/cm.
ADDITIONAL DATA: Reference samples from lab pedon number: 98P0288, NSSL, Lincoln, NE.