LOCATION BEARTRACKER CA

Established Series
Rev. EWB-JBF
03/2017

BEARTRACKER SERIES

The Beartracker series consists of shallow, well drained soils that formed in residuum and colluvium derived from andesitic rocks and tuff-breccia with surficial additions of eolian volcanic ash. Beartracker soils are on hills and mountains. Slopes are 15 to 50 percent. The mean annual precipitation is about 380 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Ashy-skeletal, glassy, frigid Lithic Haploxerolls

TYPICAL PEDON: Beartracker extremely cobbly ashy loamy sand--forest land. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with 25 percent gravel, 25 percent cobbles, 15 percent stones, and 5 percent boulders.

A1--0 to 8 cm; brown (10YR 5/3) extremely cobbly ashy loamy sand, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine roots; many very fine interstitial pores; 5 percent subangular boulders, 10 percent subangular stones, 30 percent subangular cobbles, and 25 percent subangular gravel; slightly acid (pH 6.2); clear wavy boundary. (3 to 35 cm thick)

A2--8 to 20 cm; brown (10YR 5/3) extremely cobbly ashy sandy loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and fine roots and few medium roots; common very fine and fine tubular and common very fine interstitial pores; 10 percent subangular stones, 40 percent subangular cobbles, and 25 percent subangular gravel; neutral (pH 6.7); clear wavy boundary. (8 to 20 cm thick)

A3--20 to 37 cm; brown (10YR 5/3) extremely cobbly ashy sandy loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few fine and medium roots and many very coarse roots and common very fine roots; few fine tubular and many very fine and fine interstitial pores; 10 percent subangular stones, 25 percent subangular cobbles, and 45 percent subangular gravel; neutral (pH 6.7); abrupt irregular boundary. (8 to 25 cm thick)

R--37 to 62 cm; andesitic tuff bedrock.

TYPE LOCATION: Mono County, California; in the Bodie Hills about 2.75 kilometers southeast of Mount Biedeman; in a nonsectionized township; USGS Bodie 7.5 minute topographic quadrangle; latitude 38 degrees 08 minutes 22.7 seconds N and longitude 119 degrees 02 minutes 35.4 seconds W; WGS84 Decimal Degrees 38.1396389 latitude, -119.0431667 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in the moisture control section during fall, winter, and spring; usually dry July through early October; Xeric moisture regime that borders on aridic.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 25 to 50 cm.
Depth to bedrock: 37 to 50 cm to a lithic contact.

Particle-size control section - Clay content: Averages 7 to 12 percent.
Rock fragments: Averages 60 to 80 percent, mainly cobbles. Lithology of rock fragments is volcanic rock such as andesitic tuff.

A horizons
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3 dry or moist.
Organic matter content: 1 to 3 percent.
Reaction: Slightly acid or neutral.
Clay content: 7 to 12 percent.
Rock fragments: 60 to 80 percent.
Volcanic glass content: 30 to 70 percent in coarse silt through fine sand fractions.

COMPETING SERIES: These are the Chanybuck, Copenhagen, and Kunceider series.

Chanybuck soils have lithic contacts at depths of 13 to 25 cm and have 10 to 18 percent clay in the particle-size control section. Copenhagen soils have 15 to 25 percent clay in the particle-size control section and have volcanic glass content of 70 to 90 percent. Kunceider soils have an aridic moisture regime.

GEOGRAPHIC SETTING: Beartracker soils are on hills and mountains. They typically occur on backslope positions. They formed in residuum and colluvium derived from andesitic rocks and tuff-breccia with surficial additions of eolian volcanic ash. The probable sources of the volcanic ash are the Mono Craters and Long Valley Caldera in eastern California. Slopes are 15 to 50 percent. Elevations range from 2,000 to 2,700 meters. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 350 to 400 mm, the mean annual temperature is 6 to 7 degrees C, and the frost-free period is 40 to 70 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bodiehill and Monolake soils. Bodiehill soils are very deep, have argillic horizons, and have horizons with secondary silica. Monolake soils are moderately deep with lithic contacts at depths of 50 to 100 centimeters and have an aridic moisture regime.

DRAINAGE AND PERMEABILITY: Well drained; medium surface runoff; moderately rapid permeability; high saturated hydraulic conductivity.

USE AND VEGETATION: Beartracker soils are used for forest land, recreation, watershed, and wildlife habitat. The native vegetation is mainly a forest canopy of singleleaf pinyon with an understory of mountain big sagebrush, antelope bitterbrush, and currant.

DISTRIBUTION AND EXTENT: Eastern California, in the western part of the Great Basin. These soils are not extensive. MLRA 26.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Mono County (Coleville-Bridgeport Area), California, 2010.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 37 cm (A1, A2, and A3 horizons).
Lithic contact - The boundary at 37 cm to underlying hard, unweathered bedrock (R layer).
Particle-size control section and ashy-skeletal substitute class with glassy mineralogy - The zone from 25 to 37 cm (part of the A3 horizon).

ADDITIONAL DATA: Previous authors and editors include: AMB-TM-JVC.
User Pedon ID: 2007CA051010.

National Cooperative Soil Survey
U.S.A.