LOCATION GIBSONVILLE CAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, amorphic, frigid, shallow Humic Haploxerands
TYPICAL PEDON: Gibsonville gravelly loam - on a southwest facing ridgetop with a slope of 10 percent under white fir, red fir and whitethorn at 5,600 feet elevation. When described the soil was moist throughout (colors are for dry soil unless otherwise stated.)
0--3 to 0 inches; conifer needles and deciduous duff.
A1--0 to 4 inches dark grayish brown (10YR 4/2) gravelly loam, very dark brown (10YR 2/2) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine and common medium roots; 30 percent pebbles; slightly acid (pH 6.5); clear smooth boundary. (2 to 4 inches thick)
A2--4 to 8 inches; dark yellowish brown (10YR 4/4) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; common very fine, many fine and medium roots; many very fine interstitial pores; 20 percent pebbles; slightly acid (pH 6.5); clear smooth boundary. (4 to 7 inches thick)
Bw1--8 to 12 inches; Pale brown (10YR 6/3) very cobbly sandy loam, dark yellowish brown (10YR 3/4) moist; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine, many medium and coarse roots; many very fine interstitial pores; 40 percent cobbles and 20 percent pebbles; slightly acid (pH 6.3); clear wavy boundary. (2 to 5 inches thick)
Bw2--12 to 17 inches; yellowish brown (10YR 5/4) very cobbly sandy loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, fine, many medium and coarse roots; 40 percent cobbles and 20 percent pebbles; medium acid (pH 6.0); abrupt wavy boundary. (4 to 8 inches thick)
Cr--17 to 32 inches; weathered andesitic tuff breccia with some root penetration in cracks to 30 inches.
TYPE LOCATION: Plumas County, California; 3 miles southwest of Deanes Valley Campground in the northeast corner of sec. 12, T. 23 N., R. 8 E. Meadow Valley Quadrangle.
RANGE OF CHARACTERISTICS: Depth to a paralithic contact is 12 to 20 inches. Gravel, cobbles and stones vary from 15 to 60 percent throughout the profile but average more than 35 percent in the control section. The mean annual soil temperature is less than 47 degrees F. The soil from 7 inches to the paralithic contact becomes moist in November or early December and remains moist until May. The soil is slightly acid or medium acid throughout.
The A horizon has a hue of 7.5YR or 10YR, value of 3 or 4 dry and 2 or 3 moist, and chroma of 2, 3, or 4 dry and 2 moist. It is a gravelly or cobbly loam or sandy loam, averaging 10 to 15 percent clay. 15 to 35 percent gravel or cobbles.
The Bw horizon has hue of 7.5YR or 10YR, value of 3, 5 or 6 dry and 2, 3 or 4 moist, and chroma of 3, 4 or 6 dry and 2 or 4 moist. It is very cobbly, cobbly or extremely cobbly, the fine-earth fraction is sandy loam or heavy sandy loam,
and rock fragments include 15 to 25 percent gravel and 20 to 45 percent cobbles and stones.
COMPETING SERIES: There are no other soils in this family.
GEOGRAPHIC SETTING: Gibsonville soils are on steep sideslopes and on ridgetops. Slopes are 2 to 75 percent. These soils are formed from andesitic tuff breccia. Elevations are 5,300 to 6,500 feet. At elevations of 5,300 to 5,800 feet these soils are located in cold air drainages and rain shadows with annual temperatures of 40 degrees to 44 degrees F., but typically the temperature range is 44 degrees to 47 degrees F. Mean annual precipitation is 40 to 80 inches. Frost-free days range from 40 to 65 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Waca and Woodseye. Waca soils typically are located in concave drainages under moderately dense vegetation. Woodseye soils are on barren ridgetops and exposed sideslopes.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Used for commercial timber production, wildlife habitat, livestock production and watershed. Principal vegetation is white fir, red fir, whitethorn, silktassle and wooley mule's ear.
DISTRIBUTION AND EXTENT: The northeastern uplands of the Sierra Nevada range, from Gibsonville Ridge to Beckwourth Peak. The soils of this series are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Plumas National Forest Area, California 1983.
REMARKS: Series established to use series family name.
OSED scanned by SSQA. Last revised by state on 4/84.
Series reclassified 5/95. Competing series not updated at that time.