LOCATION SKYROCK            CA 
Established Series
Rev. DWH/WCL/DJE/CEJ
7/98

SKYROCK SERIES


The Skyrock series consists of shallow, somewhat excessively drained soils formed in residuum and colluvium weathered from mica schist. These soils are on mountains. Slope ranges from 50 to 75 percent. Mean annual precipitation is about 65 inches. Mean annual temperature is about 44 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, active, frigid Lithic Dystroxerepts

TYPICAL PEDON: Skyrock extremely gravelly loam on--north facing convex slope of 75 percent under shrub tanoak, canyon live oak, and whitethorn ceanothus at an elevation of 4,400 feet. (Colors are for dry soil unless otherwise stated. When described on August 6, 1984, the soil was dry.)

The soil surface is partially covered by 80 percent gravel and 1 percent stones.

A--0 to 4 inches; light yellowish brown (10YR 6/4) extremely gravelly loam, dark yellowish brown (10YR 3/4) moist; weak very fine subangular blocky structure; loose, slightly sticky and slightly plastic; few fine, common very fine roots; few fine and very fine tubular pores; 75 percent gravel; slightly acid (pH 6.5); clear wavy boundary. (3 to 5 inches thick)

Bw1--4 to 10 inches; light yellowish brown (10YR 6/4) very gravelly loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium and fine, common very fine roots; few fine and very fine tubular pores; 55 percent gravel; strongly acid (pH 5.5); gradual boundary. (5 to 7 inches thick)

Bw2--10 to 18 inches; light yellowish brown and yellow (10YR 6/4, 7/6) extremely gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, slightly sticky and slightly plastic; few medium and fine, common very fine roots; few fine and very fine tubular pores; 65 percent gravel; strongly acid (pH 5.5); abrupt wavy boundary. (2 to 8 inches thick)

R--18 inches; broken mica schist; pieces are 1 to 8 inches across; some pockets of weathered rock; roots extend into some fractures.

TYPE LOCATION: Trinity County, California; about 1 mile northwest of Gunsight Peak; take Reading Creek Road to junction with Indian Creek Road, take Indian Creek Road 2.5 miles, turn south onto dirt road, go 0.7 mile, take right fork, go 1.3 miles, take left fork, go 0.6 mile, take left fork, go 1.0 mile, take left fork, go 3.2 miles, take left fork, go 0.4 mile, take right fork, go 1.5 miles, pedon uphill 20 feet from road; 900 feet west, 400 feet north, southeast corner, section 12, T.31 N., R.9 W. Hoosimbim Mtn. Quadrangle.

RANGE IN CHARACTERISTICS: Depth to bedrock is 10 to 20 inches. The particle-size control section contains 15 to 40 percent mica minerals in the very fine sand fraction. It also contains 18 to 25 percent clay, and 40 to 65 percent pebbles and 0 to 5 percent cobbles. The soil moisture control section is dry in all parts from about mid July to mid October (75 to 85 days). The soil temperature at a depth of 18 inches exceeds 41 degrees F from about mid May to mid November (180 days), and exceeds 47 degrees F from about mid June to mid October. The mean annual soil temperature is 45 to 47 degrees F.

The A horizon is 10YR 6/4, 6/3, or 5/3. Moist color is 10YR 3/4, 3/3, or 4/4. Reaction is moderately acid or slightly acid.

The Bw horizon moist color is 10YR 4/4, 3/4, or 4/6. It is very gravelly loam, extremely gravelly loam, or extremely gravelly sandy clay loam. Reaction ranges from strongly acid to slightly acid.

COMPETING SERIES: This is the Skymor (T) series. The Skymor soils are dry for less than 75 days and lack significant influence of mica minerals.

GEOGRAPHIC SETTING: The Skyrock soils are on mountain slopes of 50 to 75 percent. Elevation is 3,900 to 5,800 feet. These soils formed in residuum and colluvium weathered from mica schist. The climate is characterized by cool, moist winters and warm, dry summers. Mean annual precipitation is 60 to 75 inches. Mean January temperature is about 38 degrees F. Mean July temperature is about 68 degrees F. Mean annual temperature is 43 to 45 degrees F. Frost-free period is 70 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: This is the Beargulch series. Beargulch soils are 40 to 60 inches deep to bedrock.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very rapid runoff; moderate permeability.

USE AND VEGETATION: The Skyrock soils are used mainly for water supply and wildlife habitat. Natural vegetation is shrub tanoak, canyon live oak, whitethorn ceanothus, and California scrub oak.

DISTRIBUTION AND EXTENT: The Skyrock soils are not extensive; and are in the Klamath Mountains of northern California. MLRA is 5.

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

SERIES ESTABLISHED: Trinity County, California, Weaverville Area, 1990. Name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon--the zone from the surface to 4 inches (A).

Cambic horizon--the zone from 4 to 18 inches (Bw1, Bw2).

Particle-size control section-- the zone from 10 to 18 inches (Bw2).

Lithic contact--the boundary at 18 inches (R).


National Cooperative Soil Survey
U.S.A.