LOCATION HARSKEL CA+NVEstablished Series
TAXONOMIC CLASS: Ashy-skeletal, glassy, frigid, shallow Vitritorrandic Argixerolls
TYPICAL PEDON: Harskel extremely cobbly ashy loam--rangeland (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; brown (10YR 5/3) extremely cobbly ashy loam, very dark grayish brown (10YR 3/2) moist; strong thick platy structure; slightly hard, very friable, moderately sticky and moderately plastic; many very fine roots; many very fine and common fine vesicular pores; 35 percent cobbles and 30 percent pebbles; slightly acid (pH 6.2); clear wavy boundary. (1 to 3 inches thick)
Bt1--3 to 8 inches; brown (7.5YR 4/3) very cobbly ashy loam, very dark brown (7.5YR 2.5/3) moist; strong fine and medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine and fine roots; many very fine tubular pores; common faint and distinct clay films on faces of peds and lining pores; 25 percent cobbles and 20 percent pebbles; slightly acid (pH 6.4); clear wavy boundary. (4 to 9 inches thick)
Bt2--8 to 19 inches; brown (7.5YR 4/3) extremely cobbly ashy loam, very dark brown (7.5YR 2.5/3) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine and fine roots; many very fine tubular pores; many faint and common distinct clay films on faces of peds and lining pores; 40 percent cobbles and 35 percent pebbles; neutral (pH 6.8); clear irregular boundary. (3 to 9 inches thick)
Cr--19 to 24 inches; soft, weathered, vesicular andesite; nearly massive; few roots and some soil in some fractures.
TYPE LOCATION: Lassen County, California; about 650 feet east and 1600 feet north of the southwest corner of Section 3, T. 37 N., R. 17 E. Little Hat Mountain 7.5 minute topographic quadrangle; 41 degrees, 05 minutes, 58.8 seconds north latitude and 120 degrees, 02 minutes, 09.6 seconds west longitude, NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture - Moist in winter and spring, dry from July through October; aridic moisture regime that borders on xeric.
Mean annual soil temperature - 44 to 47 degrees F.
Mollic epipedon thickness - 14 to 19 inches, includes all or part of the Bt horizon.
Depth to bedrock - 14 to 20 inches to a paralithic contact. The paralithic materials below the contact are andesitic tuffs.
Volcanic glass content - 35 to 60 percent in the coarse silt through fine sand fractions.
Control section - Clay content: 18 to 27 percent.
Rock fragments: 45 to 75 percent, mostly cobbles and pebbles Lithology of fragments are volcanic rocks such as andesite, basalt and tuff.
A horizon - Hue: 10YR or 7.5 YR
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Reaction: Slightly acid or neutral.
Bt horizon - Hue: 10YR or 7.5YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Structure: Angular blocky or subangular blocky.
Rock fragments: 40 to 75 percent cobbles and pebbles.
Consistence: Slightly hard or hard dry.
COMPETING SERIES: This is the Halfash series. The Halfash soils are dominated by pebbles.
GEOGRAPHIC SETTING: Harskel soils are on plateaus. They formed in residuum and colluvium derived from andesitic tuff and similar volcanic rocks with a high content of volcanic ash. Slopes are 8 to 50 percent. Elevations range from 5,310 to 6,930 feet. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 12 to 14 inches, mean annual temperature is 43 to 45 degrees F., and the frost-free period is 80 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bitner and Devada soils. Bitner soils are ashy, are moderately deep to paralithic contacts and do not have argillic horizons. Devada soils are clayey and shallow to lithic contacts.
DRAINAGE AND PERMEABILITY: Well drained; medium surface runoff; moderately rapid permeability.
USE AND VEGETATION: Harskel soils are used for livestock grazing and wildlife habitat. The present vegetation is mainly mountain big sagebrush, antelope bitterbrush, bluebunch wheatgrass, Thurber's needlegrass, and basin wildrye.
DISTRIBUTION AND EXTENT: Eastern Lassen County, California. MLRA 23. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Surprise Valley-Home Camp Area, California and Nevada, 2004.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 19 inches (A, Bt1 and Bt2 horizons).
Argillic horizon - The zone from 3 to 19 inches (Bt1 and the Bt2 horizons).
Paralithic contact - The boundary at 19 inches to underlying soft bedrock (Cr layer).
Particle size control section - The zone from 3 to 19 inches (Bt1 and Bt2 horizons).
Vitritorrandic feature, ashy texture modifiers and glassy mineralogy - 35 to 60 percent glassy material in all horizons.