LOCATION ASPOCKET                CA

Established Series
Rev. EWB-JVC-JBF
02/2017

ASPOCKET SERIES

The Aspocket series consists of deep, well drained soils that formed in colluvium and residuum derived from tuff, tuff-breccia, and andesite. Aspocket soils are on mountains. Slopes are 4 to 30 percent. The mean annual precipitation is about 760 mm and the mean annual temperature is about 4 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, isotic Pachic Argicryolls

TYPICAL PEDON: Aspocket gravelly sandy loam--forest land. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with 15 percent gravel and 3 percent stones.

A1--0 to 13 cm; dark grayish brown (10YR 4/2) gravelly sandy loam, very dark brown (10YR 2/2) moist, moderate fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine roots; common very fine and fine tubular and interstitial pores; 15 percent gravel and 5 percent stones; neutral (pH 6.8); clear wavy boundary. (8 to 18 cm thick)

A2--13 to 33 cm; dark grayish brown (10YR 4/2) very stony loam, very dark brown (10YR 2/2) moist; moderate fine and medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; many very fine through coarse roots; common very fine tubular and interstitial pores; 25 percent gravel and 10 percent stones; neutral (pH 6.7); clear wavy boundary. (13 to 30 cm thick)

Bt1--33 to 56 cm; brown (7.5YR 5/2) very stony loam, dark brown (7.5YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine through coarse roots; common very fine tubular and interstitial pores; common faint clay bridges between sand grains; 25 percent gravel and 20 percent stones; slightly acid (pH 6.4); clear wavy boundary. (18 to 30 cm thick)

Bt2--56 to 97 cm; brown (7.5YR 5/3) very stony clay loam, dark brown (7.5YR 3/3) moist; strong medium subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; common very fine through coarse roots; common very fine tubular and interstitial pores; common distinct clay films on faces of peds and lining pores; 30 percent gravel and 25 percent stones; slightly acid (pH 6.4); clear wavy boundary. (20 to 50 cm thick)

2Bt3--97 to 137 cm; brown (7.5YR 5/4) gravelly clay loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; few very fine and common fine through coarse roots; common very fine tubular and interstitial pores; common distinct clay films on faces of peds and lining pores; 15 percent gravel and 5 percent cobbles; 30 percent paragravel; slightly acid (pH 6.4). (25 to 46 cm thick)

2Cr--137 to 163 cm; weathered andesitic tuff.

TYPE LOCATION: Alpine County, California; on the Toiyabe National Forest about 0.75 mile north of the Fire Lookout on Leviathan Peak; approximately 1,100 feet north and 700 feet east of the southwest corner of section 19, T. 10 N., R. 21 E.; USGS Heenan Lake 7.5 minute topographic quadrangle; 38 degrees 41 minutes 44.4 seconds north latitude and 119 degrees 36 minutes 40.3 seconds west longitude, WGS84 Decimal Degrees 38.6956667 latitude, -119.6111944 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in the moisture control section during late fall, winter, and spring; dry from July through early October; xeric soil moisture regime.
Mean annual soil temperature: 7 to 8 degrees C.
Mean summer soil temperature: 8 to 11 degrees C.
Mollic epipedon thickness: 76 to 127 cm, includes the Bt1 and Bt2 horizons.
Depth to base of argillic horizon: 100 to 152 cm.
Depth to bedrock: 100 to 152 cm to a paralithic contact. The paralithic materials below the contact are weathered volcanic rock such as andesitic tuff.
Reaction: Slightly acid or neutral.
Sodium fluoride pH: 8.5 to 9.5.

Particle-size control section - Clay content: Averages 18 to 27 percent.
Rock fragments: Averages 35 to 60 percent. Lithology of fragments are volcanic rocks such as tuff, tuff-breccia, and andesite.

A horizons
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 1 or 2, dry or moist.
Organic matter content: 5 to 8 percent.

Bt1 and Bt2 horizons
Hue: 10YR or 7.5YR.
Chroma: 2 or 3, dry or moist.
Texture: Very stony loam or very stony clay loam.
Clay content: 18 to 27 percent.
Rock fragments: 35 to 60 percent.
Organic matter content: 2 to 4 percent.

2Bt3 horizon
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 4 or 6 dry or moist.
Texture: Gravelly clay loam, very gravelly clay loam, or very gravelly loam.
Clay content: 25 to 35 percent.
Rock fragments: 15 to 50 percent.
Pararock fragments: 15 to 30 percent paragravel.

COMPETING SERIES: There are currently no other series in this family.

GEOGRAPHIC SETTING: Aspocket soils are on mountains. They typically occur on footslope positions. They formed in colluvium and residuum derived from tuff, tuff-breccia, and andesite. Slopes are 4 to 30 percent. Elevations range from 2,130 to 3,050 meters. The climate is subhumid-continental with cold, moist winters and cool, dry summers. The mean annual precipitation is 500 to 1,150 mm, mean annual temperature is 2 to 6 degrees C, and the frost-free period is 30 to 60 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Celeridge, Monibasin, and Vermdig soils. Celeridge soils are shallow to lithic contacts and have mixed mineralogy. Monibasin soils are very deep and have mixed mineralogy. Vermdig soils have mollic epipedons less than 41 cm thick, have aquic conditions within 100 cm of the soil surface during the spring and early summer, and have mixed mineralogy.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium surface runoff; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Aspocket soils are used for forest land, recreation, watershed, and wildlife habitat. The native vegetation is mainly a forest canopy of quaking aspen with an understory of snowberry, mountain brome, and bluegrass.

DISTRIBUTION AND EXTENT: Eastern California, on the east side of the Sierra Nevada Range. These soils are not extensive with about 4,200 acres of the series mapped to date. MLRAs 22A and 26.

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

SERIES ESTABLISHED: Alpine County (Toiyabe National Forest Area), California, 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 97 cm (A1, A2, Bt1, and Bt2 horizons).
Argillic horizon - The zone from 33 to 137 cm (Bt1, Bt2, and 2Bt3 horizons).
Paralithic contact - The boundary at 137 cm to underlying soft, weathered bedrock (2Cr layer).
Particle-size control section - The zone from 33 to 137 cm (Bt1 horizon and part of the Bt2 horizon).

The isotic mineralogy class is based on the field determined values for sodium fluoride pH.

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National Cooperative Soil Survey
U.S.A.