LOCATION PASOPEAK CA
Established Series
Rev: EJR/KP/ET
12/2015
PASOPEAK SERIES
The Pasopeak series consists of shallow, well drained soils that formed in residuum and colluvium from rhyolite and altered granitic rock. The Pasopeak soils are on summits and sideslopes of hills and mountains with slopes of 30 to 75 percent. The mean annual temperature is about 64 degrees and the mean annual precipitation is about 4 inches.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Lithic Haplargids
TYPICAL PEDON: Pasopeak very gravelly fine sandy loam on a 33 percent slope with an aspect of 120 degrees at an elevation of 2,660 feet. (Colors are for dry soil unless otherwise noted. When described on May 11, 1998, the soil was moist throughout.) The soil surface is covered with approximately 3 percent stones, 15 percent cobbles, 60 percent gravel.
A--0 to 2 inches; pale brown (10YR 6/3) very gravelly fine sandy loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine roots throughout; common very fine interstitial pores; noneffervescent; 40 percent angular metamorphic gravel and 5 percent angular metamorphic cobbles; slightly alkaline (pH 7.5); abrupt wavy boundary. (1 to 3 inches thick)
Bt--2 to 6 inches; brown (7.5YR 5/4) very gravelly sandy loam, brown (7.5YR 4/4) moist; moderate medium and coarse subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and few fine roots throughout; few very fine and fine interstitial pores and common very fine tubular pores and few fine tubular pores; few faint patchy clay bridges between sand grains; noneffervescent; 40 percent angular metamorphic gravel and 20 percent angular metamorphic cobbles; slightly alkaline (pH 7.8); abrupt wavy boundary. (4 to 6 inches thick)
R/Bt2--6 to 19 inches; 90 percent hard fractured metamorphic rock with little rotational displacement; cracks containing roots are about 8 to 10 inches apart in the R component; 10 percent yellowish brown (10YR 5/6) sandy clay loam, dark yellowish brown (10YR 4/6) moist occurring in cracks and pockets that are 0.1 to 0.3 inches wide (Bt part); moderate fine subangular blocky structure; very hard, friable, moderately sticky and moderately plastic; very few very fine and fine roots; few very fine interstitial pores; common faint patchy clay bridges between sand grains; noneffervescent; slightly alkaline (pH 7.8); abrupt irregular boundary. (12 to 14 inches thick)
R--19 inches; hard fractured rhyolite bedrock.
TYPE LOCATION: Kern County, California; 715 meters south and 510 meters west of the northeast corner of section 26, T 30 S., R 36 E., MDBM; USGS Cinco, California 7.5 minute topographic quadrangle; 35 degrees, 17 minutes, 51.20 seconds north latitude and 118 degrees, 4 minutes, 49.30 seconds west longitude; UTM 11S 401772e 3906575n (DTM: NAD83).
RANGE IN CHARACTERISTICS:
Soil moisture control section- Usually dry, moist in some part during winter and spring and intermittingly moist near the soil surface following occasional summer convection storms. The soils have a Typic-Aridic soil moisture regime.
Soil temperature: 15 to 22 degrees C.
Depth to argillic: 1 to 3 inches.
Depth to bedrock: 8 to 20 inches.
Control section Clay content: averages 20 to 30 percent.
Rock fragments: averages 35 percent or more, with individual horizons ranging from 25 to 80 percent gravel, 0 to 20 percent cobbles and 0 to 20 percent stones.
A horizon
Hue: 10YR or 7.5YR.
Chroma: 3 or 4, moist or dry.
Clay content: 10 to 18 percent.
Bt horizon
Hue: 5YR, 7.5YR, or 10YR.
Value: 5 to 7, dry.
Chroma: 4 to 6, moist or dry.
Clay content: ranges 16 to 35 percent.
Texture of the fine-earth: Sandy loam or sandy clay loam.
Rock fragments: 25 to 80 percent gravel, 0 to 20 percent cobbles and 0 to 20 percent stones with a weighted average of more than 35% coarse fragments by volume.
COMPETING SERIES: These are the
Artillery and
Newera soils. Artillery soils are moist for 10 to 20 days cumulative between July and October and have 12 to 18 percent clay in the control section. Newera soils are moist for 10 to 20 days cumulative between July and October.
GEOGRAPHIC SETTING: The Pasopeak soils are on summits and sideslopes of hills and mountains with slopes of 30 to 60 percent. Elevations are 2,400 to 3,400 feet. The climate is arid with hot, dry summers and cool, partly moist winters. The mean annual precipitation is 3 to 7 inches, most of the moisture falls as rain in the winter. The average January temperature is 46 degrees F.; the average July temperature is 84 degrees F.; and the mean annual temperature is 61 to 65 degrees F. The frost free season is 210 to 270 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Randsburg soils. Randsburg soils are underlain by soft granite at depths less than 20 inches.
DRAINAGE AND PERMEABILITY: Well drained, high to very high runoff, moderately slow permeability.
USE AND VEGETATION: Used mainly for wildlife habitat and recreation. Native vegetation is stands of creosotebush, white bursage and other desert shrubs. Annual grasses and forbs are present in the winter and spring. These consist mostly of schismus, filaree and brittle spineflower.
DISTRIBUTION AND EXTENT: Hills and mountains in the Mojave Desert of southern California; MLRA 30. These soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA
SERIES ESTABLISHED: Kern County, California, 2007; Jawbone-Butterbredt Off-Highway Vehicle Area, part of the Mojave Desert Area, Northwest Part, California.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon, 0 to 2 inches (A horizon)
Argillic horizon, 2 to 19 inches (Bt Horizon)
Lithic contact, 19 inches
Particle size control section: 2 to 19 inches
Series name is from nearby El Paso Peak.
Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 5/2007. ET
National Cooperative Soil Survey
U.S.A.