LOCATION ZEIBRIGHT CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Humic Dystroxerepts
TYPICAL PEDON: Zeibright gravelly fine sandy loam - on a north facing slope of 10 percent. Vegetation is mixed conifer with white fir, Douglas-fir, incense-cedar, ponderosa pine, and sugar pine. Elevation is 5,200 feet. (Colors are for dry soil unless otherwise stated. When described on June 16, 1975 the soil was dry throughout).
A1--0 to 12 inches, dark brown (10YR 3/3) gravelly fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine and fine interstitial pores; 15 percent gravel and 5 percent cobbles and stones; slightly acid (pH 6.5); clear irregular boundary. (10 to 15 inches thick)
A2--12 to 21 inches, brown (10YR 4/3) gravelly fine sandy loam, dark yellowish brown (10YR 3/4) moist; weak medium subangular blocky structure; soft, friable, nonsticky and nonplastic; common very fine and fine roots; common very fine interstitial pores; 20 percent pebbles and 10 parent cobbles and stones; slightly acid (pH 6.5); gradual smooth boundary. (5 to 10 inches thick)
C1--21 to 31 inches, yellowish brown (10YR 5/4) very cobbly fine sandy loam, dark yellowish brown (10YR 4/4) moist; massive; soft, friable, nonsticky and nonplastic; few fine, medium and coarse roots; few very fine interstitial pores; 15 percent pebbles, 35 percent cobbles and 5 percent stones; strongly acid (pH 5.5); clear smooth boundary. (10 to 20 inches thick)
C2--31 to 50 inches, yellowish brown (10YR 5/6) very cobbly fine sandy loam, brown (7.5YR 4/4) moist; massive; soft, friable, nonsticky and nonplastic, few fine, medium and coarse roots; few very fine interstitial pores; 15 percent pebbles, 35 percent cobbles and 5 percent stones; strongly acid (pH 5.5); clear smooth boundary. (10 to 20 inches thick)
C3--50 to 62 inches, light yellowish brown (10YR 6/4) cobbly fine sandy loam, yellowish brown (10YR 5/4) moist; massive, soft, friable, nonsticky and nonplastic; common medium and coarse roots; few very fine interstitial pores; 15 percent gravel and 20 percent cobbles and stones; strongly acid (pH 5.5). (0 to 15 inches)
TYPE LOCATION: Nevada County, California, 3 miles west of Emigrant Gap, 0.4 miles southwest of State Hwy 20, along Lowell Hill Road, near center of NE 1/2 of section 34, T.17 N., R.11 E., HB&M.
RANGE IN CHARACTERISTICS: Depth to bedrock is 40 to greater than 60 inches. The thickness of the umbric epipedon ranges from 8 to 20 inches. The mean annual soil temperature is between 47 to 55 degrees F. The soil between the depths of 9 to 30 inches is usually dry all of the time from late July until late September or early October and is moist in some or all parts the rest of the year. Cobbles and stones range from 10 to 70 percent throughout the profile with the textural control section averaging more than 35 percent rock fragments.
The A horizon has dry colors of 10YR 3/2, 3/3, 4/2, 4/3, 4/4, 5/2, 5/3, 5/4; 7.5YR 3/2, 4/2; 5YR 3/3, 4/3. Moist colors are 10YR 2/1, 2/2, 3/2, 3/3. Texture is fine sandy loam, coarse sandy loam, or sandy loam and is modified by 10 to 65 percent gravel and/or 10 to 40 percent cobbles.
The C horizon has dry colors of 10YR 4/3, 4/4, 5/3, 5/4, 5/6, 6/3, 6/4, 6/6; 7.5YR 4/4, 5/4, 6/4; 5YR 4/4, 5/4, 5/6, 6/4. Moist colors are 10YR 3/3, 3/4, 4/3, 4/4, 4/6. Texture is fine sandy loam, coarse sandy loam or sandy loam and is modified by 15 to 30 percent gravel and 20 to 50 percent cobbles and 0 to 30 percent stones. It is slightly to strongly acid.
COMPETING SERIES: There are no competing series in the same family. Similar series are the Coyata, Delphi, Meeks and Schneider in other families. Coyata, Delphi and Schneider soils have cambic horizons. Meeks soils are sandy-skeletal and frigid.
GEOGRAPHIC SETTING: Zeibright soils are on slopes that range from 2 to 75 percent. They formed in glacial granitic colluvium deposits derived from mixed sources. Elevations range from 3,500 to 6,000 feet. The climate is subhumid having a mean annual precipitation of 45 to 70 inches, some of which occurs as snow. Average January temperature is 34 degrees F; average July temperature is 65 to 70 degrees F; mean annual temperature is 43 to 51 degrees F. Frost-free season is about 100 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chaix, Hurlbut, McCarthy and Putt soils. Chaix soils are non-skeletal, are moderately deep, and are forming on granite. Hurlbut soils are moderately deep, on metasedimentary rock and are non-skeletal. McCarthy soils are moderately deep to andesitic mud flow and are influenced by amorphous material. Putt soils have a weakly cemented layer within 40 inches and are influenced by amorphous material.
DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Used for timber production. Vegetation is mainly mixed conifer-hardwood. Mostly ponderosa pine, Douglas-fir, white fir, incense-cedar, deer brush, gooseberry, elderberry, bear clover, bracken-fern and sugar pine. Black oak is the dominant hardwood. Mountain whitethorn and greenleaf manzanita are the dominant shrubs.
DISTRIBUTION AND EXTENT: These soils occur at the middle mountain areas of the Sierra Nevada Mountains in California. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Nevada County (Tahoe National Forest Area), California, 1982.
REMARKS: The classification was updated in February 2001 using the Eighth Edition to Soil Taxonomy. This series was formerly classified as loamy-skeletal, mixed, mesic Entic Xerumbrepts. Competing series were not checked at that time.
Diagnostic horizons and features recognized in this pedon are:
Umbric horizon - 0 to 12 inches (A horizon)
Entic feature - do not have a cambic horizon.
Particle-size control section - 10 to 40 inches.