LOCATION GOVSTANFORD CAEstablished Series
TAXONOMIC CLASS: Coarse-loamy over clayey, mixed over smectitic, superactive, nonacid, thermic Oxyaquic Xerofluvents
TYPICAL PEDON: Govstanford loam on less than 1 percent slope under a cover of almonds at an elevation of 139 feet, (42 m). When described on 11/22/1993, the soil was moist throughout. (Colors are for dry soil unless otherwise noted)
Ap1--0 to 3 inches, (0 to 8 cm); pale brown (10YR 6/3) loam, dark brown (10YR 3/3) moist; 17 percent clay; moderate medium platy structure parting to moderate medium subangular and moderate fine granular; moderately hard, firm, nonsticky and slightly plastic; many very fine roots; few fine tubular pores; slightly acid, pH 6.5 pH by Hellige-Truog; clear smooth boundary.
Ap2--3 to 11 inches, (8 to 28 cm); pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; 21 percent clay weak fine subangular blocky structure; hard, very firm, slightly sticky and slightly plastic; common very fine, fine and medium and few coarse roots; few fine tubular pores; neutral, pH 6.8 by pH Hellige-Truog; clear wavy boundary. (Combined thickness of the Ap horizon is 3 to 12 inches, (8 to 30 cm) thick).
C1--11 to 18 inches, (28 to 46 cm); light yellowish brown (10YR 6/4) sandy loam, brown (10YR 4/3) moist; 5 percent clay weak medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many fine, common very fine and medium and few coarse roots; few fine tubular and common fine interstitial pores; neutral, pH 7.0 pH by Hellige-Truog; clear smooth boundary.
C2--18 to 25 inches, (46 to 64 cm); yellowish brown (10YR 5/4) silt loam, brown (10YR 4/3) moist; 13 percent clay; weak medium subangular blocky structure; hard, very firm, nonsticky and nonplastic; few very fine and fine roots; common irregular tubular and irregular pores; slightly alkaline, pH 7.5 pH by Hellige-Truog; clear smooth boundary.
C3--25 to 34 inches, (64 to 86 cm); yellowish brown (10YR 5/4) silt loam, brown (10YR 4/3) moist; 9 percent clay; weak medium subangular blocky structure; hard, very firm, nonsticky and nonplastic; few very fine, fine and coarse roots; common very fine and fine tubular pores; common fine distinct brown (7.5YR 4/4 ) moist, thread shaped soft oxidized iron masses and common fine faint dark grayish brown (10YR 4/2) moist, irregularly shaped soft iron depletions; slightly alkaline, pH 7.5 pH by Hellige-Truog; abrupt smooth boundary. (Combined thickness of the C horizon is 10 to 28 inches, (25 to 71 cm) thick)
2Assg--34 to 42 inches, (86 to 107 cm); black (10YR 2/1) clay, black (10YR 2/1) moist; 56 percent clay; moderate fine subangular blocky structure; extremely hard, slightly rigid, very sticky and very plastic; few very fine and medium roots; few fine tubular pores; common intersecting slickensides; slightly alkaline, pH 7.5 pH by Hellige-Truog; clear smooth boundary. (8 to 26 inches, (20 to 66 cm) thick)
2Bssg1--42 to 61 inches, (107 to 155 cm); very dark gray (10YR 3/1) silty clay, very dark brown (10YR 2/2) moist; 56 percent clay; moderate medium subangular blocky structure; extremely hard, slightly rigid, very sticky and very plastic; few very fine and fine roots; few fine tubular pores; many intersecting slickensides; moderately alkaline, pH 8.0 pH by Hellige-Truog; clear smooth boundary.
2Bssg2--61 to 72 inches, (155 to 183 cm); very dark grayish brown (10YR 3/2) silty clay, very dark grayish brown (10YR 3/2) moist; 52 percent clay moderate medium subangular blocky structure; extremely hard, slightly rigid; very sticky and very plastic; few fine tubular pores; common intersecting slickensides; moderately alkaline, pH 8.0 pH by Hellige-Truog. (Combined thickness of the 2Bssg horizon is 7 to 31 inches, (18 to 79 cm) thick).
TYPE LOCATION: Butte County, California; about 2.3 miles south of Durham, approximately 200 feet north of where the Old Sacramento Northern Railroad crossed Butte Creek and 100 feet west of the old tracks; in an unsectionized area in the Esquon Land Grant; 39 degrees, 37 minutes, 0 seconds North latitude and 121 degrees, 46 minutes, 38 seconds West longitude, NAD27. U.S.G.S. Quad: Nelson, California.
RANGE IN CHARACTERISTICS: Depth to the lithologic discontinuity is 20 to 36 inches, (51 to 91 cm). The mean annual soil temperature is 62 to 66 degrees F, (17 to 19 degrees C). The soil moisture control section is dry from June to October (120 to 150 days). The particle-size control section averages 4 to 17 percent clay in the coarse-loamy material and 40 to 60 percent in the clayey material. Mineralogy is mixed in the coarse-loamy material and smectitic in the clayey material. Organic matter ranges from 1 to 2 percent to a depth of 11 inches, (28 cm). Intersecting slickensides range from common to many in the 2Assg and 2Bssg horizons from 34 to 72 inches, (86 to 183 cm). A fluctuating water table can occur at depths of 20 to 72 inches, (51 to 183 cm) below the surface of the soil from December through April. In some pedons oxidized iron masses, iron-manganese concretions and manganese masses occur in the underlying basin material.
The Ap horizon dry color is 10YR 5/3, 6/2 or 6/3. Moist color is 10YR 3/3, 4/2 or 4/3. Texture is loam, fine sandy loam or sandy loam. Clay content ranges from 15 to 27 percent. Reaction ranges from slightly acid to slightly alkaline.
The upper C horizon dry color is 10YR 6/2, 6/3, 6/4, 7/2 or 7/3. Moist color is 10YR 4/2, 4/3, 4/4, 5/2, 5/3 or 5/4. Texture is sand, loamy sand, sandy loam, fine sandy loam, loam or silt loam. Clay content ranges from 3 to 18 percent. Reaction ranges from neutral to moderately alkaline.
The lower C horizon dry color is 10YR 6/2, 6/3, 6/4, 7/2 or 7/3. Moist color is 10YR 4/2, 4/3, 4/4, 5/2, 5/3 or 5/4. Texture is sand, loamy sand, sandy loam, fine sandy loam, loam, silt loam or silt. Clay content ranges from 5 to 18 percent. Redoximorphic features such as oxidized iron masses (7.5YR 3/4, 4/4 and 4/6) moist, and iron depletions (10YR 4/2) moist, occur in pores and on ped faces in this part of the horizon. Reaction ranges from neutral to moderately alkaline.
The 2Assg horizon dry color is 10YR 2/1, 3/1, 4/1, 5/1 or 4/2. Moist color is 10YR 2/1, 3/1, 4/1 or 3/2. Texture is silty clay or clay. Clay content ranges from 40 to 60 percent. Reaction ranges from neutral to moderately alkaline.
The 2Bssg horizon dry color is 10YR 2/2, 3/2, 4/1, 5/1, 5/2 or 6/2. Moist color is 10YR 3/1, 3/2, 4/1 or 4/2. Texture is silty clay, clay or silty clay loam. Clay content ranges from 35 to 55 percent. Reaction ranges from neutral to moderately alkaline.
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Govstanford soils are on flood plains and alluvial fans over flood basins. Slopes range from 0 to 1 percent. These soils formed in hydraulic mine sediment (slickens) over basin alluvium. Elevation is 110 to 160 feet, (34 to 49 m). The mean annual precipitation is 20 to 23 inches, (508 to 584 mm). The mean annual temperature is 61 to 62 degrees F, (16 to 17 degrees C). Frost free season is 245 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Esquon, Neerdobe, Edjobe, Busacca and Conejo soils. Esquon soils are deep to a duripan, are fine and are in basins. Neerdobe soils are moderately deep to a duripan, are fine and are in basins. Edjobe soils are fine and are on basin rims. Busacca soils are fine and on distal fans. Conejo soils are fine-loamy and are on distal fans.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; medium runoff; moderate to moderately rapid saturated hydraulic conductivity in the Ap horizon, moderate to rapid in the C horizon, slow in the 2Assg and 2Bssg1 horizons and moderately slow to slow in the 2Bssg2 horizon. The soils are occasionally flooded for brief periods in December through March inside the levees. A fluctuating water table can occur at depths of 20 to 72 inches, (51 to 183 cm) below the surface of the soil from December through April.
USE AND VEGETATION: This soil is used for orchards, pasture, home site development, row crops and wildlife habitat.
DISTRIBUTION AND EXTENT: Butte County, California. MLRA 17 - Sacramento Valley. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California 2005. Source of name is coined.
REMARKS: These soils were previously mapped as Stockton overwash in the Soil Survey of Chico Area, California 1926.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - zone from 0 to 11 inches, (0 to 28 cm) (Ap1, Ap2)
Lithologic discontinuity at 34 inches, (86 cm).