LOCATION SWANBERGER CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Cumulic Vertic Epiaquolls
TYPICAL PEDON: Swanberger muck on a level slope under a cover of tules and sedges at an elevation of 4240 feet. +(Colors are for dry soil unless, otherwise stated. When described August 20, 1987, the soil was moist throughout.)
Oa--0 to 5 inches; very dark gray (10YR 3/1) muck (sapric material); black (10YR 2/1) moist; common fine distinct strong brown (7.5YR 5/6) mottles; weak very fine subangular blocky structure; soft, friable, nonsticky and nonplastic; common fine and many very fine roots; common very fine interstitial pores; neutral (pH 7.0); abrupt smooth boundary. (3 to 6 inches thick)
Bg--5 to 15 inches; dark gray (N 4/0) clay, dark greenish gray (5BG 4/1) moist; strong coarse prismatic tructure; extremely hard, extremely firm, very sticky and very plastic; common very fine and fine roots; common very fine tubular pores; moderately alkaline (pH 8.0); gradual smooth boundary. (8 to 12 inches thick)
Bgk1--15 to 34 inches; gray (10YR 5/1) clay, dark greenish gray (5BG 4/1) moist; moderate fine prismatic structure; extremely hard, extremely firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; strongly effervescent, lime segregated in common fine and medium soft masses; moderately alkaline (pH 8.0); abrupt smooth boundary. (13 to 18 inches thick)
Bgk2--34 to 41 inches; gray (10YR 5/1) clay, dark greenish gray (5G 4/1) moist; common fine distinct dark brown (10YR 3/3) mottles; moderate fine angular blocky structure; extremely hard, firm, sticky and plastic; few very fine tubular pores; strongly effervescent, lime segregated in common, fine and medium soft masses; moderately alkaline (pH 8.0); abrupt smooth boundary. (5 to 8 inches thick)
Bk1--41 to 45 inches; pale brown (10YR 6/3) silty clay, dark brown (10YR 3/3) moist; common fine distinct dark gray (5Y 4/1) mottles; moderate fine angular blocky structure; extremely hard, firm, sticky and plastic; few very fine tubular pores; strongly effervescent, lime segregated in common medium soft masses; strongly alkaline (pH 8.5); clear smooth boundary. (3 to 6 inches thick)
Bk2--45 to 57 inches; pale brown (10YR 6/3) clay loam, brown (10YR 4/3) moist; many fine distinct gray (5N/0) mottles; weak fine prismatic structure parting to fine angular blocky; very hard, very firm, sticky and plastic; few very fine tubular pores; strongly effervescent with disseminated lime strongly alkaline (pH 8.5); abrupt smooth boundary. (8 to 14 inches thick)
Bk3--57 to 75 inches; very pale brown (10YR 7/3) clay loam, brown (10YR 4/3) moist; many fine distinct gray (5N/0) mottles; moderate fine prismatic structure parting to fine angular blocky; hard, very firm, sticky and plastic; few very fine tubular pores; strongly effervescent with disseminated lime; strongly alkaline (pH 8.5).
TYPE LOCATION: Modoc County, California; about 10.5 miles northwest of the town of Lookout, 2950 feet W and 900 feet N from the SE corner of Sec 4, T.40N, R.6E Whitehorse SE (Egglake) Quadrangle (7.5 minute series).
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 26 to 44 inches thick. The mean annual soil temperature is 47 to 50 degrees F. The soil temperature exceeds 41 degrees F. From about March 15 to about December 31 (270 to 285 days) and exceeds 47 degrees F. from about May 1 to about December 1. The soil moisture control section (4 to 16 inches) is never dry in all parts but is moist in all parts from about January 1 to about December 31. The particle-size control section ranges from 40 to 60 percent clay. Surface cracks 0.25 to 0.5 inches wide extend to 12 to 17 inches deep. Some pedons have a weakly cemented duripan below 60 inches.
The Oa horizon color is 10YR 3/1, 4/1, 5/1, 4/2 or N 3/0. Moist color is 10YR 2/1, 3/1, 4/1, 3/2 or N 3/0. Organic matter ranges from 20 to 27 percent. Texture is muck. Clay content ranges from 30 to 35 percent. Reaction ranges from neutral to mildly alkaline.
The Bg horizon color is N 4/0; 10YR 4/1, 5/1 or 4/2. Moist color is 5BG 4/1; 2N/0; 10YR 2/1, 4/1 3/2 or N 3/0. Organic matter ranges from 2 to 3 percent. Texture is clay or silty clay. Clay content ranges from 40 to 60 percent. Reaction ranges from mildly alkaline to moderately alkaline.
The Bgk horizon color is 10YR 4/1, 5/1, 4/2, or 5Y 5/1. Moist color is 5BG 4/1; 10YR 2/1, 4/1; 5G 4/1; N 3/0, 4/0; or 5Y 4/1. Organic matter ranges from 2 to 3 percent. Texture is clay or silty clay. Clay content ranges from 40 to 60 percent.
The Bk horizon color is 10YR 4/1, 6/2, 7/2, 6/3, 7/3; 2.5Y 4/2 or 5Y 4/1. Moist color is 10YR 4/2, 3/3, 4/3; 5Y 3/1, 4/1; 2.5Y 3/2 or 6/2. Organic matter ranges from 0.5 to 1 percent. Texture is silty clay or clay loam. Clay content ranges from 35 to 50 percent. Reaction ranges from moderately alkaline to strongly alkaline.
Some pedons have an A horizon. The A horizon color is 10YR 3/1 or 4/1. Moist color is 10YR 2/1 or N2/0. Texture is clay. Clay content ranges from 40 to 50 percent. Organic matter ranges from 5 to 10 percent. Reaction ranges from neutral to mildly alkaline.
COMPETING SERIES: These are the Cove (OR), Darwin (IL), Kings (IN), Luton (IA), Macken (SD), Rail (OR), Rantoul (IL), and Woodbury (IA) soils. Carlow soils have moderately acid to very strongly acid reaction and have a mollic epipedon 10 to 20 inches thick. Cove soils lack carbonates, and have neutral to slightly acid reaction in the Bg horizon. Darwin and Kings soils have a mollic epipedon less than 24 inches thick. Luton series lack carbonates above 36 inches and have solum thickness of 36 to 60 inches. Macken soils have solum thickness of 30 to 50 inches. Rail soils are dry for 60 to 70 days and cracks to more than 20 inches and are somewhat poorly drained. Rantoul soils have slightly acid to neutral reaction in the upper Bg horizon. Wabash soils lack carbonates above 40 inches. Woodbury soils have solum thickness of 36 to 48 inches, lack carbonates above 36 inches and have a mollic epipedon less than 20 inches thick.
GEOGRAPHIC SETTING: Swanberger soils are in basins. Slopes are 0 to 1 percent. These soils formed in alluvium weathered from mixed volcanic rock. Elevation is 3100 to 4800 feet. The climate is subhumid with warm dry summers and cold moist winters. Mean annual precipitation is 16 to 35 inches. Snowfall is 48 to 60 inches. The mean annual temperature is 45 to 48 degrees F. The mean January temperature is about 32 degrees F. The mean July temperature is about 65 degrees F. Frost-free period is 50 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lasvar (T) and Pitvar (T) soils. Lasvar soils are in basins and drainageways, and are moderately deep to a duripan. Pitvar soils are in basins and drainageways and are deep to a duripan.
DRAINAGE AND PERMEABILITY: Very poorly drained; ponded runoff; slow permeability. A perched fluctuating water table occurs at the surface to depths of 4 feet from February through June.
USE AND VEGETATION: This soil is used for livestock grazing and wildlife habitat. The natural vegetation is tules, rushes and sedges.
DISTRIBUTION AND EXTENT: Northeastern California. The soils are not extensive. MLRA is 22.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Modoc County, Big Valley Soil Survey Area, California 1994. Source of name is Swanberger reservoir.
REMARKS: Series reclassified on September, 1994. Competing series not reviewed at that time.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon-the zone from 5 inches to about 41 inches. (Bg, Bgk1, Bgk2)