LOCATION CORBETT NV+CAEstablished Series
TAXONOMIC CLASS: Mixed, frigid Typic Xeropsamments
TYPICAL PEDON: Corbett bouldery sand--forestland. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 1 inch; slightly decomposed pine needle duff; abrupt wavy boundary. (0 to 2 inches thick)
A1--1 to 3 inches; dark grayish brown (10YR 4/2) bouldery sand, very dark brown (10YR 2/2) moist; massive; soft, very friable, nonsticky and nonplastic; common fine and very fine roots; many very fine and fine interstitial pores; 20 percent gravel, 10 percent boulders; moderately acid (pH 6.0) clear smooth boundary. (2 to 5 inches thick)
A2--3 to 9 inches; grayish brown (10YR 5/2) bouldery coarse sand, very dark grayish brown (10YR 3/2) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine through coarse roots; many very fine and fine interstitial pores; 20 percent gravel, 10 percent boulders; slightly acid (pH 6.4); clear wavy boundary. (4 to 7 inches thick)
C1--9 to 17 inches; pale brown (10YR 6/3) gravelly loamy coarse sand, brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine through coarse roots; many very fine and fine interstitial pores; 25 percent fine gravel; slightly acid (pH 6.4); gradual wavy boundary. (6 to 10 inches thick)
C2--17 to 32 inches; pale brown (10YR 6/3) gravelly loamy coarse sand, brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine through coarse roots; many very fine and fine interstitial pores; 25 percent fine gravel; slightly acid (pH 6.4); abrupt irregular boundary. (6 to 21 inches thick)
Cr--32 inches; weathered granodiorite.
TYPE LOCATION: Washoe County, Nevada; on the Toiyabe National Forest between Washoe Valley and Little Valley; about 600 feet east and 1,320 feet north of the southwest corner of section 16, T. 16 N., R. 19 E.; USGS Carson City 7.5 minute topographic quadrangle; 39 degrees 14 minutes 54 seconds north latitude and 119 degrees 51 minutes 39 seconds west longitude, NAD27; UTM zone 11N 253030E, 4348216N, NAD83.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in late fall, winter, and spring; usually dry July through early October; Xeric moisture regime.
Mean annual soil temperature - 45 to 48 degrees F.
Mean annual summer soil temperature - 55 to 62 degrees F.
Ochric epipedon thickness - 6 to 9 inches.
Depth to bedrock - 20 to 40 inches to a paralithic contact. The paralithic materials below the contact are weathered granitic rock.
Reaction - Slightly acid through strongly acid.
Particle-size control section - Clay content: 0 to 5 percent; Rock fragments: 5 to 35 percent, mostly fine pebbles. Lithology of fragments is granitic rocks such as granodiorite or granite.
Base saturation - 50 to 75 percent, but is greater than 60 percent in some part between 10 and 30 inches.
A horizons - Hue: 10YR or 2.5Y.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 1 through 3, dry or moist.
C horizons - Hue: 10YR or 2.5Y.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Gravelly coarse sand, gravelly loamy coarse sand, gravelly loamy sand, or sand.
COMPETING SERIES: These are the Juniperbute, Sacheen, and Shellrock series. Juniperbute and Sacheen soils are very deep. Shellrock soils have a paralithic contact at depths of 40 to 60 inches.
GEOGRAPHIC SETTING: Corbett soils are on mountains. They mostly occur on north and east-facing footslopes and backslopes. They formed in residuum and colluvium derived from granitic rocks such as granodiorite or granite. Slopes are 4 to 75 percent. Rock outcrop is common. The mean annual precipitation is 16 to 35 inches which occurs mostly as snow. The frost-free period is 50 to 90 days. Elevations range from 5,500 to 8,000 feet. The mean annual temperature is 39 to 45 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Toiyabe and Vicee soils. Toiyabe soils are shallow. Vicee soils very deep, coarse-loamy, and have mollic epipedons.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; low through high surface runoff; rapid permeability (high or very high saturated hydraulic conductivity).
USE AND VEGETATION: Corbett soils are used for forestland and wildlife habitat. The vegetation is principally a forest canopy of Jeffrey pine with an understory of pinemat manzanita and antelope bitterbrush.
DISTRIBUTION AND EXTENT: Western Nevada and northern California. These soils are moderately extensive. The series concept and main acreage is in MLRA 22A, while other acreage occurs in MLRAs 5 and 26.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Carson City Area, Nevada, 1975.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 9 inches (Oi, A1, and A2 horizons).
Paralithic contact - The boundary at 32 inches to underlying weathered bedrock (Cr layer).
Particle-size control section - The zone from 10 to 32 inches (C2 horizon and part of the C1 horizon).