LOCATION ARKRIGHT CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, parasesquic, mesic Ultic Haploxeralfs
TYPICAL PEDON: Arkright gravelly loam on a north facing 2 percent slope under a cover of Ponderosa pine at an elevation of 3120 feet. (Colors are for dry soil unless otherwise stated. When described June 24 , 1987, the soil was dry throughout.)
Oi--1 to 0 inches; pine needles in various stages of decomposition.
A1--0 to 3 inches; brown (7.5YR 5/4) gravelly loam, dark brown (7.5YR 3/2) moist; moderate very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; many very fine interstitial pores; 15 percent gravel; slightly acid (pH 6.5); clear smooth boundary. (2 to 4 inches thick)
A2--3 to 10 inches; brown (7.5YR 5/4) gravelly loam, dark brown (7.5YR 3/4) moist; moderate very fine and fine granular structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine interstitial pores; 15 percent gravel and 5 percent cobbles; slightly acid (pH 6.5); clear smooth boundary. (3 to 8 inches thick)
Bt1--10 to 14 inches; reddish brown (5YR 4/4) gravelly loam, dark reddish brown (5YR 3/4) moist; moderate medium angular blocky structure; hard, very friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; common very fine tubular pores; common thin clay films on peds and in pores; 15 percent gravel and 5 percent cobbles; slightly acid (pH 6.5); gradual smooth boundary.
Bt2--14 to 24 inches; reddish brown (5YR 4/4) cobbly clay loam, dark reddish brown (5YR 3/4) moist; moderate medium angular blocky structure; hard, very friable, sticky and plastic; few very fine, fine, and medium roots; common very fine tubular pores; common moderately thick clay films on peds and in pores; 10 percent gravel and 20 percent cobbles; slightly acid (pH 6.5); abrupt wavy boundary. (Combined thickness of the Bt horizon is 13 to 30 inches)
Cr--24 inches; weathered fractured vesicular basalt.
TYPE LOCATION: Shasta County, California; about 1 mile east of Cassel, 2,500 feet south and 1,300 feet west of the northeast corner of sec. 4, T. 35 N., R. 3 E., Burney NE (Cassel) Quadrangle (7.5 minute series)
RANGE IN CHARACTERISTICS: Depth to the paralithic contact is 20 to 40 inches. The mean annual soil temperature is 47 to 50 degrees F. The soil temperature exceeds 41 degrees F from early March to late December (300 days) and exceeds 47 degrees F. from mid April to mid November. The soil moisture control section is dry in all parts from early July to early November (140-160 days) and is moist in all parts from mid December to mid May. The particle size control section ranges from 25 to 35 percent clay and 5 to 35 percent rock fragments, mostly gravel. NaF pH is 8.5 to 9.0 and decreases with depth.
The A horizon color is 7.5YR, 4/4, 5/4, or 5/2. Moist color is 7.5YR 3/2, 3/4; 5YR 3/2, 3/3 or 3/4. Clay content ranges from 18 to 25 percent. Iron oxide ranges from 4.5 to 7.5 percent. Rock fragments, mostly gravel or cobbles, range from 15 to 25 percent. Reaction is moderately acid or slightly acid. Base saturation by sum of cations ranges from 50 to 75 percent. Organic matter ranges from 2 to 6 percent.
The Bt horizon color is 5YR 4/4, 5/4, or 5/6. Moist color is 2.5YR or 5YR 3/4. Texture is gravelly loam, cobbly loam, gravelly clay loam or cobbly clay loam. Clay content ranges from 25 to 35 percent. Iron oxide ranges from 5 to 8.5 percent. Rock fragments, mostly gravel or cobbles, averages from 15 to 35 percent. Reaction is slightly acid or neutral. Base saturation by sum of cations ranges from 35 to 75 percent.
COMPETING SERIES: This is the Burney (CA T) series. Burney soils are deep and have a combined A and Bt thickness of 40 to 60 inches.
GEOGRAPHIC SETTING: Arkright soils are on lava plateaus. Slopes are 2 to 9 percent. These soils formed in material from basalt. Elevation is 3000 to 3300 feet. The climate is subhumid with warm dry summers and cold moist winters. Mean annual precipitation is 10 to 25 inches. Snowfall is 36 to 60 inches. The mean annual temperature is 45 to 48 degrees F. The mean January temperature is about 27 degrees F. The mean July temperature is about 67 degrees F. Frost-free period is 80 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Burney, and the Hambone, and Jimmerson soils. Hambone and Jimmerson soils are on plateaus and hills and are over 40 inches deep. In addition Hambone soil have over 35 percent rock fragments.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderately slow permeability.
USE AND VEGETATION: This soil is used for timber production. Small areas are used for urban development. The vegetation is Ponderosa pine, Oregon white oak, California black oak, squawcarpet, sierra plum, and greenleaf manzanita.
DISTRIBUTION AND EXTENT: Northeastern California. The soils are moderately extensive. MLRA is 21
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Shasta County, Intermountain Soil Survey Area, California 1994. Source of name is from Arkright Flat.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 10 inches (A1 and A2 horizons)
Argillic horizon - The zone from 10 to 24 inches (Bt1, Bt2)
Paralithic contact - the boundary at 24 inches (Cr)
Additional Data: NSSL Lab S81CA-089-005, pedon No. 81P718; UCD sample no. 81-45-201X, lab no. 1519.