LOCATION BURMAN CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Argic Duraquolls
TYPICAL PEDON: Burman loam on a west facing 1 percent slope under a cover of low sagebrush and grasses at an elevation of 4240 feet. (Colors are for dry soil unless, otherwise stated. When described July 26, 1989, the soil was dry to 29 inches.)
A1--0 to 3 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; strong medium prismatic structure parting to fine subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; few very fine, fine and coarse roots; common very fine tubular pores; neutral (pH 6.8); abrupt smooth boundary. (3 to 5 inches thick)
A2--3 to 7 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; strong coarse prismatic structure parting to medium subangular blocky; hard, firm, sticky and plastic; common fine and medium, few coarse roots; common very fine tubular pores; neutral (pH 6.8); abrupt smooth boundary. (4 to 5 inches thick)
Bt1--7 to 11 inches; gray (10YR 5/1) clay loam, very dark gray (10YR 3/1) moist; weak medium prismatic structure parting to fine angular blocky; very hard, very firm, sticky and plastic; few fine and medium roots; common very fine and few tubular pores; few thin clay films on ped faces; 5 percent, 3mm manganese shot; neutral (pH 6.8); abrupt smooth boundary. (2 to 6 inches thick)
2Bt2--11 to 20 inches; light yellowish brown (10YR 6/4) clay, dark yellowish brown (10YR 4/4) moist; strong coarse prismatic structure parting to medium angular blocky; very hard, extremely firm, very sticky and very plastic; few fine and medium roots; few very fine tubular pores; many thick clay films on ped faces; 5 percent, 3mm manganese shot; neutral (pH 7.0); clear smooth boundary. (5 to 11 inches thick)
2Bt3--20 to 29 inches; yellowish brown (10YR 5/4) clay, dark yellowish brown (10YR 4/4) moist; strong medium angular blocky structure; very hard, extremely firm, sticky and very plastic; few fine roots; common very fine tubular pores; common moderately thick clay films on ped faces; 3 percent, 3mm manganese shot; neutral (pH 7.0); abrupt smooth boundary. (6 to 11 inches thick)
2Bqm--29 to 48 inches; strongly cemented duripan with 1mm continuous silica capping; strong fine platy structure; brittle, extremely hard; roots matted on top of capping; neutral (pH 7.0); clear smooth boundary. (18 to 25 inches thick)
3Bqm--48 to 72 inches; strongly cemented duripan with lenses of yellowish brown (10YR 5/4) gravelly sandy loam and gravelly sandy clay loam, dark yellowish brown (10YR 3/4) moist; weak thin platy structure; extremely hard, extremely firm; neutral (pH 7.0); gradual smooth boundary. (20 to 25 inches thick)
4C--72 to 80 inches; clayey lacustrine sediments.
TYPE LOCATION: Modoc County, California; about 9 miles northwest of Lookout; 1,550 feet east and 2,300 feet north of the southwest corner of sec. 15, T. 40 N., R. 6 E., Whitehorse SE (Egg Lake) quadrangle (7.5 minute series).
RANGE IN CHARACTERISTICS: Mollic epipedon is 10 to 15 inches thick and includes the upper part of the argillic horizons. Depth to duripan is 20 to 40 inches. The mean annual soil temperature is 47 to 50 degrees F. The soil temperature exceeds 41 degrees F. from mid March to late December (270 to 285 days) and exceeds 47 degrees F. from early May to early December. The soil moisture control section (6 to 18 inches) is dry in all parts from mid May to mid October (140 to 150 days) and is moist in all parts from late October to mid April. The particle-size control section ranges from 35 to 55 percent clay when mixed. Some pedons have very cobbly loam surface textures.
The A horizon color is 10YR 4/2 or 5/2. Moist color is 10YR 3/2, 3/3; or 7.5YR 3/2. Organic matter ranges from 1 to 2 percent. Clay content ranges from 20 to 30 percent.
The Bt1 horizon color is 10YR 5/1, or 5/2. Moist color is 10YR 3/1, 3/2; or 7.5YR 3/2. Organic matter ranges from 1 to 2 percent. Clay content ranges from 30 to 35 percent.
The 2Bt2 and 2Bt3 horizon color is 10YR 5/4, 6/4; or 7.5YR 5/4. Moist color is 10YR 4/4; or 7.5YR 4/4. Organic matter ranges from 0.6 to 1 percent. Clay content ranges from 45 to 60 percent. Reaction ranges from neutral to mildly alkaline.
The 2Bqm and 3Bqm reaction ranges from neutral to mildly alkaline.
COMPETING SERIES: There are no competing series at this time.
GEOGRAPHIC SETTING: Burman soils are on fan terraces and basin rims. Slopes are 0 to 2 percent. These soils formed in alluvium from extrusive igneous 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 Fleener, Gasper, Lasvar, Loveness, Patburn, Pitvar, Scarface and Swanberger soils. Fleener soils are on lava plateaus, are very deep, and are medial-skeletal over loamy-skeletal. Gasper soils are on lava plateaus and hills, have ochric epipedons, are very deep and are medial-skeletal over loamy-skeletal. Lasvar soils are in basins and drainageways, and are fine throughout. Loveness soils are on lava plateaus, are very deep and are medial over loamy. Patburn soils are in basins and drainageways, are very deep. Scarface soils are on lava plateaus and hills, are very deep, have ochric epipedons and are fine-loamy. Swanberger soils are in basins and are very deep. Pitvar soils are in basins and drainageways, are deep, and are fine throughout.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow to ponded runoff; slow permeability. A perched water table occurs from the surface to 2.5 feet from February through April.
USE AND VEGETATION: This soil is used for livestock grazing. The vegetation is low sagebrush, Idaho fescue and Thurber needlegrass.
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, Intermountain Soil Survey Area, California 1994. Name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the soil surface to 11 inches (A1, A2, Bt1)
Argillic horizon - the zone from 7 to 29 inches (Bt1, 2Bt2, 2Bt3)
Duripan - the zone from 29 to 72 inches (2Bqm, 3Bqm)