LOCATION BROWNBEAR CA
Established Series
Rev. DWH-WCL-CEJ
12/2022
BROWNBEAR SERIES
The Brownbear series consists of moderately deep, well drained soils formed in residuum and colluvium from metavolcanic or sedimentary rocks. These soils are on mountains. Slope is 15 to 75 percent. The mean annual precipitation is about 45 inches and the mean annual temperature is about 55 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Typic Haploxerepts
TYPICAL PEDON: Brownbear very gravelly loam--on an east facing slope of 71 percent under canyon live oak and Douglas-fir with an understory of poison oak, and greenleaf manzanita at and elevation of 3,350 feet. The soil surface is partially covered with 30 percent gravel. (Colors are for dry soil unless otherwise stated. When described May 19, 1983, the soil was slightly moist).
Oi--0 to 1 inches; needles, leaves and twigs mixed with gravel.
A--1 to 5 inches; brown (7.5YR 5/4) very gravelly loam, dark brown (7.5YR 3/4) moist; moderate very fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common medium and fine, many very fine roots; common very fine and fine tubular pores; 35 percent gravel, 5 percent soft weathered gravel; slightly acid (pH 6.5); clear wavy boundary. (3 to 6 inches thick).
Bt1--5 to 10 inches; light brown (7.5YR 6/4) very gravelly loam, brown (7.5YR 4/4) moist; moderate fine and very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, and medium, few coarse roots; common fine and very fine tubular pores; common thin clay films lining pores and bridging mineral grains; 35 percent gravel, 5 percent soft, weathered gravel; neutral (pH 7.0); gradual wavy boundary. (4 to 6 inches thick)
Bt2--10 to 17 inches; light brown (7.5YR 6/4) gravelly clay loam, brown (7.5YR 4/4) moist; moderate medium and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common medium, fine, and very fine, few coarse roots; few fine, common very fine tubular pores; common thin clay films lining pores and bridging between mineral grains; 25 percent gravel, 5 percent soft, weathered gravel; neutral (pH 7.0); gradual wavy boundary. (6 to 8 inches thick).
Bt3--17 to 23 inches; light brown (7.5YR 6/4) very gravelly clay loam, strong brown (7.5YR 4/6) moist; moderate medium and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few coarse and medium, common fine and very fine roots; few fine, common very fine tubular pores; common thin clay films lining pores and on ped faces; 40 percent gravel, 5 percent cobbles, 10 percent soft, weathered gravel; neutral (pH 7.0); clear wavy boundary. (5 to 7 inches thick).
C--23 to 33 inches; brownish yellow (10YR 6/6) extremely gravelly clay loam, yellowish brown (10YR 5/6) moist; weak medium and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine, common very fine roots; few very fine tubular pores; 65 percent gravel, 10 percent cobbles, 10 percent soft, weathered gravel; slightly acid (pH 6.5); abrupt wavy boundary. (2 to 13 inches thick)
R--33 inches; fractured schist bedrock, extremely broken, upper two inches more weathered.
TYPE LOCATION: Trinity County, California; about 3 miles northwest of Helena; 5.7 miles west of Junction City on Highway 299, turn north on Brock Gulch Access Road, go 4.4 miles, take left fork, go 0.7 mile to ridgetop, take jeep trail to left, go 0.6 mile take jeep trail to left again, to 0.3 mile then walk down spur trail 500 feet, pedon in roadcut; 1,100 feet east, 2,400 feet south of the northwest corner of section 14, T.34 N., R.11 W. Dedrick Quadrangle.
RANGE IN CHARACTERISTICS: Depth to bedrock ranges from 20 to 40 inches. The particle-size control section contains 23 to 30 percent clay and averages 35 to 60 percent rock fragments. The mean annual soil temperature is 54 to 59 degrees F. The soil moisture control section is dry in all parts from early July to late October (90 to 120 days). The soil temperature at a depth of 20 inches exceeds 41 degrees F from about March 15 to about December 15 (265 to 275 days), and exceeds 47 degrees F from about April 15 to November 15. Reaction is strongly acid to neutral throughout. Base saturation is greater than 60 percent (ammonium acetate) in the 10 to 30 inch zones.
The A horizon is 7.5YR 5/4, 4/6, 6/4, 10YR 5/8, 5/4, 4/4, 5/6, or 6/4. Moist color is 7.5YR 3/4, 3/2, 10YR 3/4, 3/3, 4/3, or 4/4. It has 20 to 25 percent clay.
The Bt horizon is 7.5YR 6/4, 4/6, 5/6, 7/4, 5/4, 10YR 5/6, 5/8, 7/4. Moist color is 7.5YR 4/4, 3/4, 5/4, 4/6, 10YR 4/4, 3/6, or 3/4. It is very gravelly loam, gravelly clay loam, extremely gravelly loam, extremely gravelly sandy clay loam, gravelly loam, or very gravelly clay loam.
The C horizon is 7.5YR 7/4, 6/6, 7/6, 10YR 7/6, 6/6, or 5/6. Moist color is 10YR 5/6, 4/6, 5/8, 6/8, 7.5YR 5/4, 4/4, 4/6, or 5/6. It is extremely gravelly clay loam, extremely gravelly loam, or extremely gravelly sandy clay loam.
COMPETING SERIES: These are the
Caris,
Dehart,
Indleton (T),
Itat (T),
Maki,
Macreeing (T), McGuire,
Olete, and
Pardaloe soils. The Caris and Maki soils have a mean annual soil temperature less than 54 degrees F. Dehart, Indleton, Itat, Macreeing, McGuire, and Pardaloe soils are deeper than 40 inches to bedrock. The Olete soils have hues of 2.5YR or
5YR.
GEOGRAPHIC SETTING: Brownbear soils are on mountains. Elevation is 1,400 to 4,000 feet. Slopes are 15 to 75 percent. These soils formed in residuum and colluvium from metavolcanic rocks. The climate is subhumid with warm, dry summers and cool, moist winters. Snowfall ranges from 0 to 6 inches. Mean January temperature is about 38 degrees F. Mean July temperature is about 73 degrees F. Mean annual temperature is 52 to 57 degrees F. The frost-free period is 90 to 130 days. Mean annual precipitation is 30 to 55 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Brockgulch,
Pardaloe, and
Dedrick soils. Brockgulch soils have thermic temperature regimes.
Pardaloe soils are deeper than 40 inches to bedrock. The
Dedrick soils are less than 20 inches deep over bedrock and have thermic temperature regimes.
DRAINAGE AND PERMEABILITY: Well drained; rapid to very rapid runoff; moderate permeability.
USE AND VEGETATION: This soil is used for timber production, water supply and wildlife habitat. Vegetation consists of Douglas-fir, sugar pine, canyon live oak, Pacific madrone, ponderosa pine, and poison-oak.
DISTRIBUTION AND EXTENT: The soils are not extensive. They occur in the Klamath Mountains of northern California.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Trinity County, California; Weaverville Area, 1990. Name is from Brownbear Mine.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--the zone from the surface to a depth of 5 inches (A horizon).
Cambic horizon--the zone from a depth of 5 to 23 inches (Bt1, Bt2, and Bt3 horizons).
Particle-size control section--the zone from a depth of 11 to 33 inches (Bt2, Bt3, and C horizons).
Lithic contact - the boundary at 33 inches (R).
National Cooperative Soil Survey
U.S.A.