LOCATION HARDTEPH CA

Established Series
Rev. EWB-JBF-TM-JVC
03/2017

HARDTEPH SERIES

The Hardteph series consists of very shallow and shallow, well drained soils that formed in residuum and colluvium derived from metamorphic rocks such as quartzite with surficial additions of eolian volcanic ash. Hardteph soils are on mountains and hills. Slopes are 4 to 30 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 Aridic Lithic Argixerolls

TYPICAL PEDON: Hardteph extremely gravelly ashy fine sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with 65 percent gravel, 10 percent cobbles, and 2 percent stones.

A--0 to 10 cm; brown (10YR 5/3) extremely gravelly ashy fine sandy loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine interstitial pores; 5 percent angular quartzite cobbles and 70 percent angular quartzite gravel; neutral (pH 6.8); clear wavy boundary. (5 to 13 cm thick)

Bt1--10 to 18 cm; brown (10YR 5/3) extremely gravelly ashy loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine interstitial and common very fine tubular pores; 5 percent faint clay bridges between sand grains; 5 percent angular quartzite cobbles and 70 percent angular quartzite gravel; neutral (pH 6.8); clear wavy boundary. (8 to 13 cm thick)

Bt2--18 to 33 cm; brown (10YR 5/3) extremely gravelly ashy loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; few very fine to medium roots; common very fine interstitial and tubular pores; 25 percent faint clay bridges between sand grains; 10 percent angular quartzite cobbles and 60 percent angular quartzite gravel; neutral (pH 6.9); abrupt irregular boundary. (5 to 18 cm thick)

R--33 cm; quartzite bedrock.

TYPE LOCATION: Mono County, California; in the Bodie Hills about 1 mile south of Mormon Meadow; in a nonsectionized township; T 3 N., R 26 E; USGS Big Alkali 7.5 minute topographic quadrangle; latitude 38 degrees 8 minutes 57.40 seconds N. and longitude 119 degrees 7 minutes 47.20seconds W; WGS84 Decimal Degrees 38.1492778 latitude, -119.1297778 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry in the moisture control section; moist winter and spring; usually dry July through early October; aridic moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 36 cm; includes the Bt horizons.
Depth to bedrock: 18 to 36 cm to a lithic contact.

Particle-size control section - Clay content: Averages 18 to 27 percent.
Rock fragments: Averages 60 to 85 percent, mainly angular gravel. Lithology of rock fragments is metamorphic rock such as quartzite.

A horizon
Chroma: 2 or 3, dry or moist.
Organic matter content: 1 to 3 percent.
Reaction: Slightly acid or neutral.
Volcanic glass content: 30 to 75 percent in coarse silt through fine sand fractions.

Bt1 horizon
Hue: 10YR or 7.5YR.
Chroma: 2 or 3, dry or moist.
Clay content: 18 to 25 percent.
Rock fragments: 60 to 85 percent.
Organic matter content: 1 to 3 percent.
Reaction: Slightly acid or neutral.
Volcanic glass content: 30 to 75 percent in coarse silt through fine sand fractions.

Bt2 horizon
Hue: 10YR or 7.5YR.
Chroma: 2 or 3 dry or moist.
Texture: Extremely gravelly ashy loam or extremely gravelly ashy clay loam.
Clay content: 20 to 30 percent.
Rock fragments: 60 to 85 percent.
Organic matter content: 1 to 3 percent.
Reaction: Slightly acid or neutral.
Volcanic glass content: 30 to 75 percent in coarse silt through fine sand fractions.

COMPETING SERIES: These are the Badrock, Domehill, Farepeak, Hardnut, and Schoolmarm series.

Badrock and Hardnut soils have bedrock at depths of 36 to 50 cm. Domehill, Farepeak, and Schoolmarm soils have less than 60 percent rock fragments in the particle-size control section.

GEOGRAPHIC SETTING: Hardteph soils are on mountains and hills. They typically occur on shoulder or backslope positions. They formed in residuum and colluvium derived from metamorphic rocks such as quartzite 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 4 to 30 percent. Elevations range from 2,045 to 2,625 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 350 to 400 mm, the mean annual temperature is 6 to 7 degrees F., and the frost-free period is 30 to 60 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Quartzhill and Tephzite soils. Quartzhill soils have paralithic material within 50 cm and have a xeric moisture regime. Tephzite soils have lithic contacts at depths of 150 to 200 cm and have a xeric moisture regime.

DRAINAGE AND PERMEABILITY: Well drained; moderate permeability; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Hardteph soils are used for livestock grazing, recreation, watershed and wildlife habitat. The native vegetation is mainly low sagebrush, antelope bitterbrush, bluegrass, Webber's needlegrass, and Thurber's needlegrass.

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 33 cm (A, Bt1, and Bt2 horizons).
Argillic horizon - The zone from 10 to 33 cm (Bt1 and Bt2 horizons).
Lithic contact - The boundary at 33 cm to underlying hard bedrock (R layer).
Particle-size control section and ashy-skeletal substitute class with glassy mineralogy - The zone from the soil surface to 33 cm (A, Bt1, and Bt2 horizons).

Classification was updated to 11th edition on 07/2011 changed from Lithic Argixerolls to Aridic Lithic Argixerolls.

National Cooperative Soil Survey
U.S.A.