LOCATION FLAGCANYON CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Haplic Durixeralfs
TYPICAL PEDON: Flagcanyon gravelly loam, on a west facing 4 percent slope under a cover of olives at an elevation of 380 feet, (116 m). When described on 7/16/2001 the soil was dry to a depth of 30 inches, (76 cm) and moist from 30 to 65 inches, (76 to 165 cm). (Colors are for dry soil unless otherwise noted).
A--0 to 3 inches, (0 to 8 cm); brown (10YR 4/3) gravelly loam, dark brown (10YR 3/3) moist; 18 percent clay; moderate fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic; many very fine roots; many fine irregular pores; 10 percent subrounded cobbles and 20 percent subrounded basalt gravel; very strongly acid, pH 5.1 by Hellige-Truog; clear smooth boundary. (2 to 8 inches, (5 to 20 cm) thick)
Bt1--3 to 9 inches, (8 to 23 cm); brown (10YR 4/3) very gravelly loam, dark yellowish brown (10YR 3/4) moist; 25 percent clay; moderate medium and coarse subangular blocky structure; hard, firm, slightly sticky, moderately plastic; common fine and medium roots between peds; common fine and medium irregular pores; 20 percent discontinuous faint clay films on surfaces along pores; 10 percent subrounded basalt cobbles and 30 percent subrounded basalt gravel; strongly acid, pH 5.5 by Hellige-Truog; clear wavy boundary.
Bt2--9 to 14 inches, (23 to 36 cm); dark yellowish brown (10YR 4/4) very gravelly loam, dark yellowish brown (10YR 3/4) moist; 27 percent clay; moderate medium and coarse subangular blocky structure; hard, firm, moderately sticky, moderately plastic; common very fine, fine, medium and coarse roots between peds; common very fine, fine and medium tubular and few coarse tubular pores; 30 percent discontinuous distinct clay films on surfaces along pores; 10 percent subrounded basalt cobbles and 40 percent subrounded basalt gravel; moderately acid, pH 6.0 by Hellige-Truog; clear wavy boundary.
2Bt3--14 to 30 inches, (36 to 76 cm); dark yellowish brown (10YR 4/4) very gravelly clay loam, dark yellowish brown (10YR 3/4) moist; 30 percent clay; moderate medium subangular blocky structure; hard, firm, moderately sticky, moderately plastic; common fine and medium roots around fragments; common fine and medium irregular pores; 40 percent discontinuous distinct clay films on surfaces along pores; 20 percent subrounded basalt cobbles and 40 percent subrounded basalt gravel; slightly acid, pH 6.5 by Hellige-Truog; abrupt wavy boundary. (Combined thickness of the Bt horizon is 19 to 41 inches, (48 to 104 cm) thick).
3Btq1--30 to 53 inches, (76 to 135 cm); duripan; yellowish brown (10YR 5/4) extremely gravelly sandy clay loam, dark yellowish brown (10YR 4/4) moist; 34 percent clay; moderate medium angular blocky structure; very hard, very firm, moderately cemented, cemented by silica, moderately sticky, moderately plastic; common very fine and fine roots around fragments; few fine irregular pores; 60 subrounded basalt cobbles and 50 percent subrounded basalt gravel; neutral, pH 6.8 by Hellige-Truog; abrupt wavy boundary.
3Btq2--53 to 65 inches, (135 to 165 cm); duripan; yellowish brown (10YR 5/4) extremely gravelly sandy clay, 40 percent dark yellowish brown (10YR 4/6) and 60 percent dark yellowish brown (10YR 4/4) moist; 36 percent clay; moderate medium angular blocky structure; very hard, very firm, moderately cemented, cemented by silica, moderately sticky, moderately plastic; few very fine roots around fragments; few very fine irregular pores; 45 percent continuous distinct clay films on rock fragments; 20 percent subrounded basalt cobbles and 60 percent subrounded basalt gravel; neutral, pH 7.0 by Hellige-Truog. (Combined thickness of the 3Btq horizon is 35 to 50 inches, (89 to 127 cm) or more thick).
TYPE LOCATION: Butte County, California, about 6.1 miles northwest of Oroville, approximately 1,000 feet east and 1,400 feet south of the northwest corner of Section 14, Township 20 N., Range 3 E., 39 degrees, 35 minutes, 34 seconds North latitude and 121 degrees, 36 minutes, 31 seconds West longitude, NAD83 - U.S.G.S. Quad: Oroville, California.
RANGE IN CHARACTERISTICS: Depth to duripan is 20 to 40 inches, (51 to 102 cm). The mean annual soil temperature is 62 to 64 degrees F, (17 to 18 degrees C). The particle-size control section averages 27 to 35 percent clay and 35 to 60 percent rock fragments, mostly gravel. Mineralogy is mixed. A fluctuating water table can occur between the top of the duripan and 11 inches (28 cm) below the surface of the soil from December through April. Redoximorphic features such as soft manganese masses, with colors of N 2/0 occur in the Bt and 2Bt horizons. Rock fragments on the surface range from 0 to 10 percent gravel and 0 to 15 percent cobbles.
The A horizon dry color is 10YR 4/3, 7.5YR 4/3 or 5/3. Moist color is 10YR 3/2, 3/3, 7.5YR 3/2 or 3/3. Texture is gravelly loam, loam or fine sandy loam. Clay content ranges from 15 to 22 percent. Rock fragments range from 0 to 20 percent gravel and 0 to 10 percent cobbles. Organic matter ranges from 4 to 8 percent. Reaction ranges from strongly acid to slightly acid.
The Bt horizon dry color is 10YR 4/3, 4/4, 5/3, 7.5YR 4/3, 4/4, 5/3 or 5YR 4/4. Moist color is 10YR 3/4, 7.5YR 3/4, 4/2, 4/3, 4/4 or 5YR 3/4. Texture is very gravelly loam, very gravelly clay loam, extremely gravelly clay loam or gravelly loam. Clay content ranges from 22 to 60 percent. Rock fragments range from 15 to 60 percent gravel and 0 to 30 percent cobbles. Organic matter ranges from 1 to 4 percent. Reaction ranges from strongly acid to neutral.
The 2Bt horizon dry color is 10YR 4/3, 4/4, 5/3, 7.5YR 4/3, 4/4 or 5YR 4/4. Moist color is 10YR 3/4, 4/3, 7.5YR 3/4, 4/3 or 5YR 3/4. Texture is very gravelly clay loam, extremely gravelly clay loam or extremely gravelly clay. Clay content ranges from 35 to 50 percent. Rock fragments range from 40 to 60 percent gravel and 0 to 20 percent cobbles. Organic matter ranges from 1 to 2 percent. Reaction ranges from moderately acid to neutral.
The 3Btq horizon dry color is 10YR 5/4, 5/6, 8/4, 8/6 or 7.5YR 4/4. Moist color is 10YR 4/4, 4/6, 7/6 or 7.5YR 3/4. Texture is extremely gravelly sandy clay loam or extremely gravelly sandy clay. Clay content ranges from 22 to 50 percent. Rock fragments range from 45 to 60 percent gravel and 20 to 40 percent cobbles. Cementation class ranges from slightly cemented to moderately cemented. Organic matter ranges from 0.2 to 1 percent. Reaction matter ranges from neutral to moderately alkaline.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Flagcanyon soils are on Table Mountain alluvial fans. Slopes range from 2 to 5 percent. These soils formed in alluvium weathered from basalt. Elevation is 280 to 500 feet, (85 to 152 m). Mean annual precipitation is 25 to 30 inches, (635 to 762 mm). The mean annual temperature is 60 to 62 degrees F, (16 to 17 degrees C). Frost free season is 250 to 260 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cherokeespring, Coalcanyon, Coonhollow and Wickscorner soils. Cherokeespring soils are very deep, fine loamy and have greater than 50 percent silt. Coalcanyon soils are formed in colluvium from basalt, are on side slopes of basalt plateaus, are loamy-skeletal and have a mollic epipedon. Coonhollow soils are deep to a paralithic contact, are formed in colluvium from basalt, are on side slopes of basalt plateaus, are loamy-skeletal and have a mollic epipedon. Wickscorner soils are very deep, are fine-loamy and are on middle and upper fan terraces.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium runoff; moderate saturated hydraulic conductivity in the A horizon, moderate to moderately slow in the Bt horizon, moderately slow in the 2Bt horizon and very slow in the 3Btq horizon. A fluctuating water table can occur between the top of the duripan and 11 inches (28 cm) below the surface of the soil from December through April.
USE AND VEGETATION: This soil is used for livestock grazing, wildlife habitat, watershed and orchards, mainly olives. Vegetation is soft chess, wild oat, annual brome, filaree, brodiaea, hedgehog dogtail, ripgut brome, cowbag clover, ryegrass, fiddleneck, lupine, yellow starthistle and blackberry.
DISTRIBUTION AND EXTENT: Butte County, California and occur in (262Ag) Hardpan Terraces subsection of the (262A) Great Valley section. MLRA 17 - Sacramento Valley. The soils are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California 2005. Source of name from Flag Canyon on the Oroville Quad.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - zone from 0 to 3 inches, (0 to 8 cm) (A)
Argillic horizon - zone from 3 to 30 inches, (8 to 76 cm) (Bt1, Bt2, Bt3)
Duripan - zone from 30 to 65 inches, (76 to 165 cm).
Particle-size control section for this pedon: 3 to 23 inches, (8 to 58 cm).
The soil moisture control section - zone from 10 to 30 inches, (25 to 76 cm) is dry in all parts from about June through October 15 (about 135 days).
Assumed that base saturation by sum of cations ranges from 35 to 50 percent in the argillic horizon.