LOCATION COONHOLLOW CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, parasesquic, thermic Pachic Ultic Argixerolls
TYPICAL PEDON: Coonhollow gravelly loam, on a northwest facing 45 percent slope under a cover of hardwoods, shrubs and annual grasses at an elevation of 1020 feet, (311 m). When described on 10/31/2000 the soil was moist throughout. (Colors are for dry soil unless otherwise noted).
A--0 to 3 inches, (0 to 8 cm); brown (7.5YR 4/3) gravelly loam, dark brown (7.5YR 3/2) moist; 16 percent clay; weak fine granular structure; soft, very friable, nonsticky, nonplastic; many fine roots throughout; many fine irregular pores; 10 percent basalt cobbles and 15 percent basalt gravel; neutral, pH 5.5 by pH meter 1:1 water; clear smooth boundary. (2 to 8 inches, (5 to 20 cm) thick)
ABt--3 to 11 inches, (8 to 28 cm); brown (7.5YR 4/3) very cobbly loam, dark reddish brown (5YR 3/3) moist; 19 percent clay; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common fine and medium roots throughout and few coarse roots between peds; few fine tubular and common fine irregular pores; 10 percent discontinuous distinct clay films on surfaces along pores; 15 percent basalt gravel and 30 percent basalt cobbles; neutral, pH 5.9 by pH meter 1:1 water; gradual wavy boundary. (0 to 10 inches, (0 to 25 cm) thick)
Bt1--11 to 22 inches, (28 to 56 cm); brown (7.5YR 4/3) very cobbly loam, dark reddish brown (5YR 3/3) moist; 23 percent clay; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky, slightly plastic; common fine and very coarse roots throughout; common fine tubular and common medium irregular pores; 20 percent discontinuous distinct clay films on surfaces along pores; 15 percent basalt gravel and 40 percent basalt cobbles; neutral, pH 6.1 by pH meter 1:1 water; clear wavy boundary.
Bt2--22 to 32 inches, (56 to 81 cm); brown (7.5YR 4/3) extremely cobbly loam, dark reddish brown (5YR 3/3) moist; 26 percent clay; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky, moderately plastic; common fine roots and few very fine roots between peds and few very coarse roots throughout; common medium tubular pores; 35 percent discontinuous distinct clay films on surfaces along pores; 15 percent basalt gravel and 50 percent basalt cobbles; slightly acid, pH 6.4 by pH meter 1:1 water; clear wavy boundary.
Bt3--32 to 45 inches, (81 to 114 cm); brown (7.5YR 5/3) extremely cobbly clay loam, brown (7.5YR 4/3) moist; 29 percent clay; moderate medium subangular blocky structure; hard, friable, moderately sticky, moderately plastic; few fine roots between peds and common medium roots between peds and common very coarse roots throughout; common medium tubular pores; 45 percent discontinuous distinct clay films on surfaces along pores; 20 percent basalt gravel and 55 percent basalt cobbles; slightly acid, pH 6.4 by pH meter 1:1 water; clear wavy boundary. (Combined thickness of the Bt horizon is 17 to 48 inches, (43 to 122 cm) thick).
Cr--45 to 50 inches, (114 to 127 cm); moderately cemented basalt bedrock; abrupt wavy boundary
R--50 inches, (127 cm); indurated basalt bedrock
TYPE LOCATION: Butte County, California, about 5.1 miles north of downtown Oroville, approximately 1750 feet east and 1800 feet north of the southwest corner of Section 18, Township 20N., Range 4E., 39 degrees, 35 minutes, 18 seconds North latitude and 121 degrees, 34 minutes, 15 seconds West longitude, NAD83 - U.S.G.S. Quad: Oroville, California.
RANGE IN CHARACTERISTICS: Depth to paralithic bedrock is 40 to 60 inches, (102 to 152 cm). The mean annual soil temperature is 61 to 64 degrees F, (16 to 18 degrees C). The particle-size control section averages 18 to 27 percent clay and 35 to 60 percent rock fragments, mostly gravel and cobbles. Mineralogy is mixed. Organic matter ranges from 1 to 13 percent to a depth of 32 inches, (81 cm) and is less than 1 percent to a depth of 50 inches, (127 cm). Base saturation by ammonium acetate ranges from 78 to 91 percent throughout. Base saturation by sum of cations ranges from 55 to 58 percent throughout. Rock fragments on the surface range from 10 to 60 percent gravel, 5 to 65 percent cobbles, 0 to 25 percent stones and 0 to 20 percent boulders. Some pedons have silty textures.
The A horizon dry color is 7.5YR 3/4, 4/3, 10YR 3/3, 4/3 or 5/3. Moist color is 7.5YR 3/2, 3/3, 10YR 2/2, 3/2 or 3/3. Texture is gravelly loam, loam, very gravelly loam or very cobbly loam. Clay content ranges from 16 to 22 percent. Rock fragments range from 10 to 55 percent gravel, 5 to 35 percent cobbles, 0 to 45 percent stones and 0 to 15 percent boulders. Reaction ranges from strongly acid to neutral.
The ABt horizon dry color is 7.5YR 4/3, 10YR 5/3 or 5/4. Moist color is 5YR 3/3; 7.5YR 4/3, 10YR 3/2 or 3/3. Texture is very cobbly loam, loam, gravelly loam or very gravelly loam. Clay content ranges from 18 to 22 percent. Rock fragments range from 10 to 50 percent gravel, 5 to 40 percent cobbles, 0 to 55 percent stones and 0 to 15 percent boulders. Reaction ranges from moderately acid to neutral.
The Bt horizon dry color is 7.5YR 4/3, 5/3, 5/4, 10YR 3/4, 4/3, 4/4, 5/2 or 5/3. Moist color is 5YR 3/3, 7.5YR 4/3, 3/2, 3/3 or 3/4. Texture is very cobbly loam, extremely cobbly loam, very cobbly clay loam, extremely cobbly clay loam, gravelly loam, very gravelly loam, gravelly clay loam, very gravelly clay loam or extremely gravelly clay loam. Clay content ranges from 18 to 38 percent. Rock fragments range from 15 to 80 percent gravel, 5 to 60 percent cobbles, 0 to 60 percent stones and 0 to 15 percent boulders. Reaction ranges from slightly acid to neutral.
COMPETING SERIES: This is the Coalcanyon series. Coalcanyon soils are very deep.
GEOGRAPHIC SETTING: Coonhollow soils are on convex sideslopes on basalt plateaus in volcanic Sierra Nevada foothills. Slopes are 5 to 50 percent. These soils formed in colluvium weathered from basalt. Elevation is 200 to 1500 feet, (61 to 457 m). Mean annual precipitation is 25 to 35 inches, (635 to 889 mm). The mean annual temperature is 59 to 62 degrees F, (15 to 17 degrees C). Frost free season is 240 to 260 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beatsonhollow, Campbellhills, Cherotable, Coalcanyon and Thermalrocks soils. The Beatsonhollow soils are in swales in mound-swale microtopography on basalt plateaus, are loamy-skeletal, and shallow to bedrock. Campbellhills soils are in fractures on basalt plateaus, are loamy-skeletal and deep to bedrock. Cherotable soils are on concave positions on basalt plateaus, are fine-loamy and deep to bedrock. Coalcanyon soils are very deep and are on side slopes on basalt plateaus. Thermalrocks soils are on convex positions on basalt plateaus, are loamy-skeletal, and very shallow to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; low to medium runoff; moderate saturated hydraulic conductivity in the A and Bt horizons and moderate to moderately slow in the Bt horizon.
USE AND VEGETATION: This soil is used for livestock grazing, wildlife habitat and watershed. Vegetation is interior live oak, blue oak, valley oak, foothill pine, whiteleaf manzanita, toyon, poison oak, mustard, rabbitfoot grass, wild oat, soft chess, filaree, starthistle and rose clover.
DISTRIBUTION AND EXTENT: Butte County, California and occurs in (M261Fb) Lower Foothills Metamorphic Belt subsection of the (M261F) Sierra Nevada Foothills section. MLRA 18 - Sierra Nevada Foothills. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California 2005. Source of name from canyon named Coon Hollow on the Oroville Quad.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Particle-size control section - zone from 11 to 31 in, (28 to 79 cm)
Mollic Epipedon - zone from 0 to 32 in, (0 to 81 cm) (A, ABt, Bt1, Bt2)
Argillic Horizon - zone from 11 to 45 in, (28 to 114 cm) (Bt1, Bt2, Bt3)
Paralithic Contact - zone from 45 to 50 in, (114 to 127 cm) (Cr)
Lithic Contact - 50 in, (127 cm)
The soil moisture control section - zone from 11 to 42 inches, (28 to 107 cm) is dry in all parts from about May to October (about 150 to 200 days).
Argillic horizon not supported by particle-size distribution, however believe this to be due to lack of dispersion due to iron content. Did not use lab textures.
ADDITIONAL DATA: Reference data from lab pedon number: 01N0261, NSSL, Lincoln, NE.