LOCATION RIVALIER CAEstablished Series
TAXONOMIC CLASS: Ashy-skeletal, mixed, frigid Typic Vitrixerands
TYPICAL PEDON: Rivalier very gravelly sandy loam on a NE-facing 20 percent slope under a cover of white fir, sugar pine, ponderosa pine and snowbrush ceanothus at an elevation of 5000 feet. (Colors are for dry soil unless, otherwise stated. When described June 16, 1983, the soil was dry throughout).
Oi--3 to 0 inches; partially decomposed pine and fir needles.
A--0 to 4 inches; brown (10YR 5/3) very gravelly sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine tubular pores; 35 percent gravel, 10 percent cobbles; NaF pH 11.5; slightly acid (pH 6.9); clear smooth boundary. (4 to 6 inches thick)
Bw1--4 to 18 inches; light yellowish brown (10YR 6/4) very gravelly sandy loam, dark yellowish brown (10YR 3/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many fine and common coarse roots; many very fine tubular pores; 40 percent gravel, 15 percent cobbles; NaF pH 9.6; slightly acid (pH 6.7); clear wavy boundary.
Bw2--18 to 27 inches; very pale brown (10YR 7/4) extremely gravelly sandy loam, dark yellowish brown (10YR 3/4) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; few very fine and medium roots; common very fine and fine tubular pores; 40 percent gravel, 20 percent cobbles; NaF pH 9.2; slightly acid (pH 6.5); clear wavy boundary. (Combined thickness of the Bw horizons is 16 to 34 inches)
2R--27 inches; Tuff with cracks 1/2 to 3 inches apart with less than 10 percent soil in cracks 1/8 to 1/2 inches apart.
TYPE LOCATION: Lassen County, California; about 5 miles northwest of Bieber, about 150 feet W of Section 12 SW center K-tag, upslope 20 feet from dirt road 1300 feet N and 1300 feet E of SW corner of section 12, T.38 N., R.6 E. Bieber NW (Lookout) Quadrangle (7.5 minute series).
RANGE IN CHARACTERISTICS: Depth to a lithic contact is 20 to 40 inches. The mean annual soil temperature is 44 to 47 degrees F. The soil temperature exceeds 41 degrees F.from mid May to mid November and exceeds 47 degrees F. from early July to early October. The soil moisture control section is dry in all parts from mid August to early November (75 to 90 days) and is moist in all parts from mid November to early July. Rock fragments, mostly gravel, on the soil surface, range from 35 to 50 percent. NaF pH is 9.0 to 11.0 and decreases with depth. Reaction is slightly acid or moderately acid. Base saturation by sum of cations ranges from 40 to 50 percent and decreases with depth. Moist bulk density ranges from 0.6 to 0.85 to 18 inches then increases with depth.
The A horizon color is 10YR 5/3 or 5/4. Moist color is 10YR 3/2 or 3/3. Organic matter ranges from 5 to 7 percent. Rock fragments range from 30 to 45 percent gravel and 5 to 10 percent cobbles. NaF pH is 10 to 11.5. Base saturation by sum of cations ranges from 60 to 70 percent and ammonium acetate 90 to 95 percent. Volcanic glass content of the very fine sand fraction is 65 to 75 percent.
The Bw color is 10YR 4/3, 5/4, 6/4, 7/4; or.5YR 5/4. Moist color is 10YR 3/2, 3/3, 3/4, 4/4; or 7.5YR 3/4. Organic matter ranges from 1 to 2 percent. Rock fragments range from 25 to 45 percent gravel and 10 to 20 percent cobbles. NaF pH range from 9 to 11 and decreases with depth. Base saturation by sum of cations ranges from 60 to 65 percent and ammonium acetate 70 to 80 percent. Volcanic glass content of the very fine sand fraction is 75 to 85 percent.
Andic property data (see remarks for explanation): Depth P-ret B.D. pH NaF Glass Alo Feo 15 barH20 0-4 55 0.58 10.0 45,28 0.9 0.6 15.6 4-18 42 0.86 9.9 44,39 0.7 0.6 10.1 18-27 32 1.18 9.3 39,39 0.4 0.7 10.4
COMPETING SERIES: This is the Danhunt (T CA) and Twinbuttes (T CA) series. Danhunt soils are greater than 40 inches deep. Twinbuttes soils are...
GEOGRAPHIC SETTING: Rivalier soils are on mountains. Slopes are 15 to 75 percent. These soils formed in tephra. Elevation is 4800 to 6300 feet. The climate is subhumid with warm dry summers and cold moist winters. Mean annual precipitation is 25 to 35 inches. Snowfall is 48 to 72 inches. The mean annual temperature is 39 to 45 degrees F. The mean January temperature is about 32 degrees F. The mean July temperature is about 65 degrees F. Frost-free season is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chirpchatter, Hambone, Hunsinger, Roundbarn and Said soils. Chirpchatter soils are on hills and lava plateaus, are deep, have an argillic horizon, are fine-loamy and have a mesic temperature regime. Hambone soils are on hills and lava plateaus, have an argillic horizon, are deep and have a mesic temperature regime. Hunsinger soils are on hills and plateaus, are deep, have a mollic epipedon and an argillic horizon and have mesic temperature regime. Roundbarn and Said soils are on similar positions and are deep, and fine-loamy.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; moderately rapid permeability.
USE AND VEGETATION: This soil is used for timber production. The vegetation is white fir, sugar pine, ponderosa pine, incense cedar, California blackoak, native rose, serviceberry, incense cedar, California black oak, snowbrush ceanothus and rubber rabbitbrush.
DISTRIBUTION AND EXTENT: Big Valley Mountains, Northeastern California. The soils are not extensive. MLRA is 22.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Lassen County, Intermountain Soil Survey Area California, 1985. Source of name is from a spring.
REMARKS: Series reclassified on September, 1994. Competing series not reviewed at that time.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 4 inches (A)
Cambic horizon - the zone from 4 to 27 inches (Bw1, Bw2)
Lithic contact - the boundary at 27 inches (R)
ADDITIONAL DATA: This pedon was sampled by the Lincoln Lab in 1984. Pedon number is S84CA-035-008.