LOCATION SLACREEK CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, frigid Ultic Haploxeralfs
TYPICAL PEDON: Slacreek gravelly sandy loam, on a northwest facing slope of 50 percent under Douglas-fir and white fir at an elevation of 4,150 feet. (Colors are for dry soil unless otherwise stated. When described on September 23, 1986, the soil was slightly moist throughout.)
O--0.5 to 0 inches; decomposing fir needles and twigs.
A--0 to 6 inches; brown (7.5YR 4/4) gravelly sandy loam, dark brown (7.5YR 3/4) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and few fine roots; common very fine interstitial pores; 30 percent pebbles; slightly acid (pH 6.3); clear wavy boundary. (4 to 7 inches thick)
BA--6 to 9 inches; yellowish red (5YR 5/6) gravelly loam, yellowish red (5YR 4/6) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine interstitial pores and few very fine tubular pores; 30 percent pebbles; moderately acid (pH 6.0); clear smooth boundary. (0 to 4 inches thick)
Bt1--9 to 14 inches; yellowish red (5YR 5/6) gravelly loam, yellowish red (5YR 4/6) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine, fine and few coarse roots; common very fine interstitial pores and few very fine tubular pores; few thin clay films lining pores; 30 percent pebbles; moderately acid (pH 6.0); clear smooth boundary. (3 to 6 inches thick)
Bt2--14 to 26 inches; strong brown (7.5YR 5/6) very gravelly loam, yellowish red (5YR 4/6) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine, fine and few coarse roots; common very fine interstitial pores; few thin clay films lining pores; 50 percent pebbles, 10 percent cobbles; moderately acid (pH 6.0); clear smooth boundary. (10 to 14 inches thick)
Bt3--26 to 31 inches; reddish yellow (7.5YR 6/6) very gravelly loam, strong brown (7.5YR 4/6) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine interstitial pores; common thin clay films lining pores; 50 percent pebbles, 10 percent cobbles; moderately acid (pH 5.8); abrupt wavy boundary. (3 to 6 inches thick)
Bt4--31 to 34 inches; reddish yellow (7.5YR 7/6) very gravelly loam, strong brown (7.5YR 5/6) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; few fine and coarse roots; common very fine interstitial pores; few thin clay films lining pores; 60 percent pebbles; strongly acid (pH 5.5); abrupt wavy boundary. (0 to 4 inches thick)
R--34 inches; hard fractured schist.
TYPE LOCATION: Yuba County, California; about 5 miles northeast of Northstar across Slate creek on the old Scales Road; then about 1/2 mile northwest on logging road; then about 100 feet down slope; about 2,050 feet west of the northeast corner of section 11, T.20 N., R.8 E., MDB&M. Strawberry Valley, Quadrangle.
RANGE IN CHARACTERISTICS: Depth to a lithic contact is 20 to 40 inches. The 10 to 30 inch soil moisture section is dry in all parts from about August 1 to October 1 (ranges 60 to 90 days) and moist in some or all parts the rest of the year. The mean annual soil temperature ranges from 43 to 46 degrees F. The soil temperature is above 41 degrees F from April 15 to December 1, and above 47 degrees F from June 1 to November 1.
The A and BA horizons have color of 7.5YR 4/4 and 5YR 5/6 and moist colors of 7.5YR 3/2, 3/4; 5YR 3/2, 3/3, 3/4 or 4/6. Moist chroma of 3 or less are above 6 inches. Clay content ranges from 5 to 15 percent. Gravel content ranges from 20 to 30 percent. Cobble content ranges from 0 to 10 percent.
The Bt horizon has colors of 7.5YR 4/4, 5/6, 6/6, 7/6; or 5YR 5/6 and moist colors of 7.5YR 5/6, 4/6; 5YR 4/6 or 3/4. Clay content ranges from 15 to 27 percent. Gravel content ranges from 30 to 50 percent. Cobble content ranges from 5 to 15 percent. Base saturation ranges from 35 to 50 percent.
COMPETING SERIES: These are the Agatha, Chapot (T), Euer, Inville, Jorge, Larabee (T), Lorack, Outland (T), and Rasser series. The Agatha, Euer, Inville, Jorge, and Lorack soils have bedrock at more than 40 inches. The Outland soils are dry throughout for 90 to 120 days and have a paralithic contact at 20 to 40 inches. The Rasser soils are very strongly acid and have a weighted average clay content in the textural control section of 27 to 35 percent. Chapot soils are .... Larabee soils are ....
GEOGRAPHIC SETTING: Slacreek soils are on mountains. Slopes range from 30 to 75 percent. The soils formed in the inner gorge of stream canyons in material from metamorphic rocks, mainly schist. Elevations are 3,400 to 4,850 feet on dominantly northwest, northeast, north and some east aspects. The climate is humid with warm dry summers and cold wet winters. The average annual precipitation is 75 to 85 inches with some precipitation falling as snow from December to April. Mean annual temperature is 47 to 51 degrees F. Mean January temperature is 35 degrees F. and mean July temperature is 64 degrees F. Frost-free season is 130 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Jocal and Sites soils. Jocal and Sites soils are 40 to 80 inches deep and are on sideslopes and ridgetops above Slacreek soils.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; moderate permeability.
USE AND VEGETATION: Used mainly for timber production, watershed and wildlife habitat. Native vegetation is mainly white fir and Douglas-fir with an understory of dogwood and tanoak.
DISTRIBUTION AND EXTENT: The northern Sierra Nevada mountains of California. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Yuba County, California, 1992.
REMARKS: The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET
Diagnostic horizons and features recognized in this pedon are:
1. Ochric Epipedon - 0 to 9 inches (A, BA).
1.1 Color chromas and values of 3 or less are above 6 inches.
2. Argillic Horizon: 9 to 34 inches (Bt1, Bt2, Bt3, Bt4).
2.1 Weighted average clay content of the 9 to 29 inch textural control section is 14.8 percent.
3. Ultic Subgroup:
3.1 Base Saturation Data (By Local Hach Kit) See data 2.2.
4. Temperature - Moisture Regime (Xeric-frigid):
4.1 The 10 to 30 inch SMCS is dry in all parts from August 1 to October 1 and moist in some part the rest of the year. 4.2 The soil temperature is below 47 degrees F. from November 1 to May 31 and below 41 degrees F. from December 1 to April 15. 4.3 MAST is 43 to 46 degrees F. (3 years data)