LOCATION SPRINGGULCH CAEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Haplic Palexeralfs
TYPICAL PEDON: Springgulch gravelly clay loam--on a south- southeast facing slope of 50 percent under chamise, greenleaf manzanita, chaparral oak, and wavyleaf ceanothus at an elevation of 2,800 feet. (Colors are for dry soil unless stated otherwise. When described on June 21, 1984, the soil was slightly moist below 5 inches and dry above).
The surface is covered with 5 percent pebbles.
A--0 to 4 inches; reddish brown (5YR 5/4) gravelly clay loam, dark reddish brown (2.5YR 3/4) moist; strong very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine, many very fine roots; common very fine tubular pores; 20 percent pebbles; neutral (pH 7.0); abrupt wavy boundary. (3 to 5 inches thick)
BA--4 to 7 inches; reddish brown (5YR 5/4) gravelly clay loam, dark red (2.5YR 3/6) moist; weak medium and fine subangular blocky structure; slightly hard, friable, sticky and plastic; common fine and very fine roots; common fine and very fine tubular pores; 15 percent pebbles; neutral (pH 7.0); clear wavy boundary. (2 to 5 inches thick)
Bt1--7 to 13 inches; reddish brown (5YR 5/4) gravelly clay loam, dark red (2.5YR 3/6) moist; moderate medium and fine subangular blocky structure; slightly hard, friable, sticky and plastic; common coarse, medium, fine, and very fine roots; few medium, common fine and very fine tubular pores; common thin clay films lining pores and on ped faces; 25 percent pebbles; neutral (pH 7.0); gradual wavy boundary. (5 to 8 inches thick)
Bt2--13 to 20 inches; yellowish red (5YR 4/6) gravelly clay loam, dark red (2.5YR 3/6) moist; moderate medium and fine subangular blocky structure; hard, firm, very sticky and very plastic; common coarse, medium, fine, and very fine roots; few medium, common fine tubular pores; many thin clay films lining pores and on ped faces; 25 percent pebbles; neutral (pH 7.0); gradual wavy boundary. (5 to 10 inches thick)
Bt3--20 to 34 inches; yellowish red (5YR 4/6) gravelly clay loam, dark red (2.5YR 3/6) moist; moderate medium and fine subangular blocky structure; hard, firm, very sticky and very plastic; common coarse, medium, fine and very fine roots; few medium, common fine and very fine tubular pores; many thin clay films lining pores and on ped faces; 25 percent pebbles; neutral (pH 7.0); gradual wavy boundary. (10 to 20 inches thick)
Bt4--34 to 50 inches; yellowish red (5YR 5/6) gravelly clay loam, red (2.5YR 4/6) moist; moderate medium and fine subangular blocky structure; hard, firm, very sticky and very plastic; few coarse and medium, common fine and very fine roots; few fine, common very fine tubular pores; many thin clay films lining pores and on ped faces; 30 percent pebbles; slightly acid (pH 6.5); gradual wavy boundary. (10 to 18 inches thick).
Bt5--50 to 75 inches; red (2.5YR 5/6 and 5/8) very gravelly clay loam, dark red (2.5YR 3/6) moist; moderate medium and fine subangular blocky structure; very hard, firm, very sticky and very plastic; few fine and very fine roots; few fine and very fine tubular pores; many thin clay films on ped faces and lining pores; 40 percent pebbles; neutral (pH 7.0).
TYPE LOCATION: Trinity County, California; about 3 miles southeast of Douglas City, California; Highway 3 to Reading Creek Road, take Reading Creek Road 1 mile, turn left onto Camp gulch Road, go 1.8 miles to saddle, take right 0.2 miles, take right fork go 0.8 miles, take right fork go 0.1 mile, pit in roadcut; 2,300 feet east, 1,600 feet south of the northwest corner of section 20, T.32 N., R.9 W . Hoosimbim Mtn. Quadrangle. 40 degrees North latitude 37 minutes, 13 seconds, 122 West longitude, 54 minutes, 38 seconds.
RANGE IN CHARACTERISTICS: The particle-size control section ranges from 35 to 45 percent clay, and averages 15 to 30 percent rock fragments mostly pebbles. The soil moisture control section is dry in all parts from early July to early October. The soil temperature at 20 inches exceeds 41 degrees F from about February 15 to December 31 (255 days), and exceeds 47 degrees F from about March 15 to November 30. Mean annual soil temperature is 59 to 64 degrees F. There is 15 to 25 percent mica minerals in the very fine sand fraction. Base saturation (sum of cations) ranges from 70 to 85 percent in the argillic horizon, and is below 75 percent in some part of each pedon. The ratio of extractable iron oxide plus gibbsite to clay is 0.2 to 0.3.
The A horizon is 2.5YR 5/4, 5YR 5/4 or 7.5YR 5/4. Moist color is 2.5YR 3/4, 5YR4/4 or 7.5YR 4/4. It is neutral or slightly acid.
The Bt horizon is 5YR 5/4, 5/6, 4/6, 2.5YR 4/6, 5/6, or 6/8. Moist color is 2.5YR 3/6, 4/6, 5YR 4/6, or 5/6. It is gravelly clay loam, clay loam, or gravelly clay. The lower part is very gravelly clay loam or very gravelly clay. The Bt horizon is neutral to moderately acid.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: The Springgulch soils are on mountains at elevations of 2,400 to 3,100 feet. They are on southerly facing slopes. The soils formed in colluvium and residuum from mica schist. The climate is characterized by cool, moist winters and warm, dry summers. The mean January temperature is about 39 degrees F. The mean July temperature is about 78 degrees F. The mean annual temperature is 57 to 62 degrees F. The mean annual precipitation is 40 to 50 inches. The frost-free period is 130 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the Brockgulch Variant soil. The Brockgulch Variant is less than 40 inches deep to a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderately slow permeability.
USE AND VEGETATION: Springgulch soils are used for watershed and wildlife habitat. Some trial conifer plantings have been attempted. Natural vegetation is chamise, greenleaf manzanita, wavyleaf ceanothus, and chaparral oak.
DISTRIBUTION AND EXTENT: Klamath Mountains of northern California. The soil is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Trinity County, California, Weaverville Area, 1990. Name is from Spring Gulch.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon--the zone from the surface to 7 inches (A, BA).
Argillic horizon--the zone from 7 to 75 inches (Bt1, Bt2, Bt3, Bt4, Bt5).
Particle-size control section--The zone from 7 to 27 inches (Bt1, Bt2, Bt3).
ADDITIONAL DATA: NSSL pedon S84CA-105-007. Lab results for measured clay are much lower than field estimates. Field estimates are used with assumption that mica fragments were crushed during sample preparation, which influenced results. Further investigation is needed. Mica mineral content assumed from lab data from similar soils.