LOCATION HIRIDGE NVEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, shallow Xeric Argicryolls
TYPICAL PEDON: Hiridge very gravelly sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 50 percent pebbles, 5 percent cobbles, and 2 percent stones.
A1--0 to 5 cm; grayish brown (10YR 5/2) very gravelly sandy loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; many very fine roots; many very fine and fine interstitial pores; 40 percent pebbles; neutral (pH 7.2); clear smooth boundary. (3 to 8 cm thick)
A2--5 to 10 cm; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; many very fine and fine roots; common very fine and fine interstitial, and common fine vesicular pores; 25 percent pebbles; neutral (pH 7.2); clear smooth boundary. (5 to 13 cm thick)
Bt1--10 to 23 cm; brown (10YR 4/3) very gravelly clay loam, dark brown (10YR 3/3) strong fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; many very fine and fine and common medium roots; common fine interstitial and common very fine and fine tubular pores; few faint clay films on faces of peds and lining pores; 45 percent pebbles; neutral (pH 7.2); clear wavy boundary. (8 to 15 cm thick)
Bt2--23 to 46 cm; dark yellowish brown (10YR 4/4) very gravelly clay loam, dark yellowish brown (10YR 3/4) moist; strong fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; common very fine, fine, and medium roots; common fine interstitial and common very fine and fine tubular pores; common distinct clay skins on faces of peds and lining pores; 50 percent pebbles; neutral (pH 7.2); clear wavy boundary. (10 to 25 cm thick)
Cr--46 to 58 cm; highly weathered andesite bedrock; some clay and roots in fractures.
R--58 cm; hard fractured andesite bedrock.
TYPE LOCATION: Mineral County, Nevada; on the western slope of Mt. Grant; 1,025 feet north and 1,845 feet east of the southwest corner of section 13, T. 8 N., R. 28 E.; USGS Mount Grant 7.5 minute topographic quadrangle; latitude 38 degrees 32 minutes 52 seconds N and longitude 118 degrees 48 minutes 25 seconds W; NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture - Moist in winter and spring, dry in summer and fall but intermittently moist in the upper part of the moisture control section in summer months due to rainfall from convection storms; xeric moisture regime bordering on aridic.
Soil temperature - 6 to 8 degrees C.
Mean summer soil temperature - 12 to 14 degrees C.
Thickness of mollic epipedon - 18 to 33 cm.
Depth to bedrock - 36 to 50 cm to a paralithic contact. The paralithic materials below the contact are weathered volcanic or granitic rocks. Hard bedrock is within 76 cm.
Reaction - Neutral or slightly alkaline.
Control section - Clay content: 25 to 35 percent.
Rock fragments: 35 to 60 percent, mainly pebbles. Lithology of fragments are volcanic rocks such as andesite or granitic rocks such as granite and granodiorite.
A horizons - Value: 4 or 5 dry.
Chroma: 2 or 3, dry or moist.
Structure: Weak or moderate subangular blocky.
Bt horizons - Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 3 or 4.
Texture: Very gravelly clay loam or very gravelly loam.
Structure: Moderate or strong subangular blocky structure.
Consistence: Slightly hard or hard dry, very friable or firm moist.
COMPETING SERIES: These are the Badgercamp and Bakscratch series. Both of these soils have 12 to 18 percent clay in the particle-size control section.
GEOGRAPHIC SETTING: Hiridge soils are on mountains. They typically occur on summit, shoulder, and backslope positions. They formed in residuum and colluvium derived from volcanic or granitic rocks. Slopes are 8 to 75 percent. Elevations range from 2,380 to 3,400 meters. The climate is semiarid with cold, moist winters and cool, dry summers. The mean annual precipitation is 300 to 360 mm, the mean annual temperature is 5 to 7 degrees C., and the frost-free period is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Granmount and Kiote soils. Granmount soils are clayey-skeletal, very deep, and have mollic epipedons and argillic horizons. Kiote soils are loamy-skeletal, very deep, and have argillic horizons and thick mollic epipedons.
DRAINAGE AND PERMEABILITY: Well drained; high or very high surface runoff; moderately slow permeability; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: Hiridge soils are used for rangeland and wildlife habitat. The native vegetation is mainly low sagebrush, green ephedra, Sandberg bluegrass, Letterman needlegrass, prairie junegrass, and eriogonum.
DISTRIBUTION AND EXTENT: Western Nevada. These soils are moderately extensive. MLRAs 26, 27, and 29.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES ESTABLISHED: Esmeralda County, Nevada, 1984.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 23 cm (A1, A2, and Bt1 horizons).
Argillic horizon - The zone from 10 to 46 cm (Bt1 and Bt2 horizons).
Paralithic contact - The boundary at 46 cm to underlying soft, weathered bedrock (Cr layer).
Particle-size control section - The zone from 10 to 46 cm (Bt1 and Bt2 horizons).