LOCATION PINYONPEAK CAEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Typic Haplargids
TYPICAL PEDON: Pinyonpeak gravelly sandy loam occurs on a west facing convex 30 percent slope at an elevation of 1,132 meters. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 80 percent gravel.
A--0 to 5 centimeters (0 to 2 inches); yellowish brown (10YR 5/4) gravelly sandy loam, dark yellowish brown (10YR 3/4) moist; moderate very thick platy parting to weak medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; common very fine through medium roots; common very fine interstitial pores; 30 percent gravel; neutral (pH 7.2); abrupt smooth boundary. (3 to 12 centimeters thick)
Bt--5 to 15 centimeters (2 to 6 inches); strong brown (7.5YR 4/6) gravelly coarse sandy loam, dark brown (7.5YR 3/4) moist; weak medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine through medium roots; common very fine interstitial pores; 20 percent prominent clay films bridging sand grains, 10 percent prominent clay films on rock fragments; 30 percent gravel and 25 percent paragravel; neutral (pH 7.0); abrupt irregular boundary. (10 to 28 centimeters thick)
Ct--15 to 20 centimeters (6 to 8 inches); gravel; few very fine and fine roots; 35 percent prominent clay films on rock fragments; abrupt wavy boundary. (0 to 5 centimeters thick)
Crt--20 to 40 centimeters (8 to 16 inches); weathered granitic bedrock with fractures 2 to 10 centimeters apart; 35 percent prominent clay films on rock fragments; gradual wavy boundary.
R--40 centimeters (16 inches); hard fractured granitic bedrock with fractures 10 to 20 centimeters apart.
TYPE LOCATION: Kern County, California; approximately 35 kilometers north and 6 kilometers east of the town of Mojave, California, in the extreme southern Sierra Nevada mountains; about 300 meters east and 700 meters north of the southwest corner of section 30, T. 29 S., R. 37 E, MDBM; 35 degrees, 22 minutes, 57.5 seconds north latitude and 118 degrees, 3 minutes, 27.1 seconds west longitude; USGS Dove Springs, California, 7.5 minute topographic quadrangle; UTM 11S 0403947e, 3915992n (DTM: NAD-83).
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; typic-aridic soil moisture regime.
Soil temperature: 15 to 18 degrees C.
Depth to argillic horizon: 3 to 15 centimeters.
Depth to paralithic contact: 15 to 36 centimeters.
Depth to hard bedrock: 30 to 75 centimeters.
Control section
Clay content: averages 10 to 18 percent.
Rock fragments: averages 15 to 35 percent, dominantly fine gravel with 0 to 30 percent paragravel.
Reaction: neutral or slightly alkaline.
A horizon
Value: 4 through 6 dry, and 3 through 5 moist.
Chroma: 3 or 4 dry or moist.
Clay content: 5 to 12 percent.
Consistence: soft through moderately hard, nonsticky or slightly sticky.
Structure: fine or medium or thin through thick.
Bt horizon(s)
Hue: 7.5YR or 10YR.
Value: 4 through 6 dry, 3 or 4 moist.
Chroma: 4 or 6 dry, 3 through 6 moist.
Clay content: 10 to 18 percent.
Texture: coarse sandy loam or sandy loam.
Structure: weak or moderate, fine through coarse.
Consistence: slightly hard through very hard, very friable through firm, nonsticky or slightly sticky, nonplastic or slightly plastic.
COMPETING SERIES: This is the Chimenea series. Chimemea soils have 18 to 25 percent clay in the argillic horizon, hues of 2.5YR and 5YR, and receive the majority of precipitation in the summer and winter months.
GEOGRAPHIC SETTING: Pinyonpeak soils are on upper backslopes of hills, mountains and rock pediments. Slopes range from 8 to 30 percent. The soils formed in residuum and colluvium from granitic rocks. Elevation ranges from 1,125 to 1,600 meters. The climate is arid with warm, dry summers and cool, moist winters. The mean annual precipitation ranges from 180 to 230 millimeters. The mean annual air temperature ranges from 13 to 16 degrees C. The frost-free season is 165 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Goldpeak, Grandora, and Wingap soils. Goldpeak soils occur on fan remnants and are very deep. Grandora soils occur on steep backslopes of mountains and are very deep. Wingap soils occur on lower backslopes of hills and are deep to bedrock.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; very high runoff; high saturated hydraulic conductivity in the subsoil and very low in the underlying material.
USE AND VEGETATION: These soils are used for grazing, recreation, and wildlife habitat. Present vegetation is blackbrush, California buckwheat, Sandberg bluegrass, narrowleaf rabbitbrush, Nevada ephedra, and Coopers goldenbush.
DISTRIBUTION AND EXTENT: Northwest Mojave Desert of southeastern California, U.S.A.; MLRA 29. The soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Kern County, California, 2007; Jawbone-Butterbredt Off-Highway Vehicle Area Soil Survey, part of the Mojave Desert Area, Northwest Part, California. The name is coined from Pinyon Peak which is located 29 kilometers to the northeast.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon -- 0 to 5 centimeters (A horizon).
2. Argillic horizon -- 5 to 15 centimeters (Bt horizon).
3. Particle-size control section - 0 to 20 centimeters (A, Bt and Ct horizons).
4. Paralithic contact -- 20 centimeters (Crt horizon).
5. Hard bedrock -- 40 centimeters (R horizon).