LOCATION JACKTONE CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Xeric Duraquerts
TYPICAL PEDON: Jacktone clay - on a nearly level slope of less than 1 percent in a cultivated field used for growing barley at an elevation of 37 feet. (Colors are for dry soil unless otherwise stated. When described on September 9, 1982 the soil was moist to a depth of 8 feet.)
Ap--0 to 7 inches; very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; moderate coarse prismatic structure; the upper inch has moderate medium subangular blocky structure; very hard, firm, very sticky and very plastic; common very fine roots; common very fine interstitial and tubular pores; few fine black (10YR 2/1) manganese concretions; neutral (pH 7.3); clear wavy boundary. (6 to 10 inches thick)
Bss--7 to 15 inches; very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; weak coarse prismatic structure parting to moderate coarse subangular blocky; very hard, firm, very sticky and very plastic; few very fine roots; many very fine interstitial pores and common very fine tubular pores; few fine black (10YR 2/1) manganese concretions; common intersecting slickensides; slightly effervescent with disseminated lime; neutral (pH 7.3); gradual wavy boundary. (4 to 9 inches thick)
Bssk1--15 to 22 inches; dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; common fine distinct yellowish brown (10YR 5/6) mottles; weak coarse subangular blocky structure; very hard, firm, very sticky and very plastic; few very fine roots; many very fine tubular and interstitial pores; few fine black (10YR 2/1) manganese concretions; common intersecting slickensides; strongly effervescent with disseminated lime and few fine, medium and coarse soft masses of lime; moderately alkaline (pH 8.2); gradual wavy boundary. (4 to 8 inches thick)
Bssk2--22 to 28 inches; dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; common fine yellowish brown (10YR 5/4) mottles, dark yellowish brown (10YR 4/4) moist; weak coarse subangular blocky structure; very hard, firm, very sticky and very plastic; few very fine roots; many very fine tubular and interstitial pores; few fine black (10YR 2/1) manganese concretions; common intersecting slickensides; strongly effervescent with disseminated lime and few fine, medium and coarse large soft masses of lime; strongly alkaline (pH 8.5); clear irregular boundary. (2 to 7 inches thick)
Bk--28 to 34 inches; light gray (10YR 6/1) clay loam, gray (10YR 5/1) moist; massive; very hard, firm, very sticky and plastic; common very fine tubular and interstitial pores; few fine black (10YR 2/1) manganese concretions; violently effervescent with disseminated lime and segregations of accumulated lime in large soft masses; strongly alkaline (pH 8.5); abrupt wavy boundary. (4 to 6 inches thick)
2Bqkm--34 to 37 inches; light gray (10YR 6/1) strongly cemented to indurated duripan, gray (10YR 5/1) moist; few fine yellowish brown (10YR 5/6) mottles; massive; brittle; common very fine tubular and interstitial pores; few fine (10YR 2/1) manganese concretions; indurated continuous laminar capping 1 to 5 mm thick; 75 percent silica cemented within the matrix; violently effervescent with disseminated lime and segregations of accumulated lime in coarse soft masses; moderately alkaline (pH 8.0); abrupt wavy boundary. (2 to 10 inches thick)
2Bqk--37 to 46 inches; yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 4/4) moist; massive; hard, firm, nonsticky and slightly plastic; many very fine tubular and interstitial pores; few fine black (10YR 2/1) manganese concretions; 15 percent weakly cemented durinodes within the matrix; strongly effervescent with disseminated lime; strongly alkaline (pH 8.5); clear wavy boundary. (0 to 9 inches thick)
3Bqk--46 to 60 inches; yellowish brown (10YR 5/4) weakly cemented duripan, dark yellowish brown (10YR 4/4) moist; massive; brittle; few fine manganese concretions, black (N 2/0); 40 to 70 percent silica cemented within the matrix; strongly effervescent with disseminated lime; strongly alkaline (pH 8.5).
TYPE LOCATION: San Joaquin County, California. Eight miles southeast of Stockton, 2,500 feet south and 1,350 feet west of the northeast corner of Section 10, T. 1 S., R. 7 E., Manteca quadrangle.
RANGE IN CHARACTERISTICS: Depth to duripan is 20 to 40 inches. The mean annual soil temperature is 59 to 64 degrees F. The soils have cracks 1 to 4 cm wide at a depth of 20 or more inches. The cracks open and close once each year. They are open through the summer and fall and are closed during the winter and spring. Reaction is neutral to moderately alkaline above 15 inches and moderately alkaline or strongly alkaline below 15 inches. Effervescence occurs below 15 inches.
The A horizon dry color is dominantly 10YR 5/1, 4/1, 3/1, or N 3/0 with a mixture in some pedons of 10YR 4/3, 4/2, or 3/2. Moist colors are dominantly 10YR 3/1, 2/1, N 3/0, or N 2/0 with a mixture in some pedons of 10YR 3/3, or 3/2. It is clay or silty clay.
The Bk or 2Bqk horizon has dry color of 10YR 7/2, 6/1, 6/2, 6/3, 6/4 5/4, 5/1, or 4/1 and moist color of 10YR 4/2, 4/3, 4/4, 5/1, 4/1, 3/1 or 2.5Y 5/2. It has distinct or prominent mottles, or iron-manganese concretions, or both. Texture is clay loam, silty clay or clay. The 2Bk horizon, is sandy loam, loam, sandy clay loam or clay loam and contains 0 to 15 percent hard durinodes which are counted as gravel.
The 2Bqkm horizon has dry color of 7.5Y 5/6, 6/4; 10YR 6/1, 5/6, 5/4, 4/4, 4/3, 5/2 or 4/2. Moist colors are 7.5Y 4/4; 10YR 5/1, 5/4, 4/4, 4/3, 5/2 or 4/2. It is strongly cemented to indurated with silica and carbonates in 60 to 90 percent of the horizon. Carbonates are disseminated or segregated in soft masses. A laminar cap is indurated or thin laminar bands are indurated below the upper boundary.
The 3Bqkm horizon has similar colors as the 2Bkqm horizon. It is weakly to strongly cemented with silica and carbonates in 30 to 70 percent of the horizon. Carbonates are either disseminated or segregated.
COMPETING SERIES: These are Clear Lake, Hildreth, Maxwell, Subaco and Willows series. Clear Lake, Hildreth, Maxwell, Subaco and Willows soils lack a duripan within a depth of 40 inches. Subaco soils are underlain by siltstone at depths of 20 to 40 inches.
GEOGRAPHIC SETTING: Jacktone soils are on basin rims and in basins. Slopes are 0 to 2 percent. The soils formed in fine textured alluvium from mixed igneous and sedimentary rock sources. Elevations are 5 to 100 feet. The climate is subhumid with hot dry summers and cool, foggy moist winters. Mean annual precipitation is 12 to 20 inches. Mean January temperature is 45 degrees F; the mean July temperature is 76 degrees F; and mean annual temperature is 60 to 64 degrees F. Frost-free season is 250 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cosumnes, Dierssen, Galt, Rioblancho and San Joaquin soils. Cosumnes soils lack cracks that extend from the surface to 20 inches or more. Rioblancho and San Joaquin soils lack intersecting slickensides. Galt soils have a dominant chroma of more than 1.5 in the upper 12 inches of the profile.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; runoff is very slow or slow; slow permeability. These soils are subject to rare flooding. Depth to water table is presently greater than 5 feet because of pumping and deep drainage ditches. The soil may be saturated above the duripan with a perched water table for short periods after heavy rains during the winter months.
USE AND VEGETATION: These soils are used for irrigated cropland to grow rice, row crops and field crops. Beans, peppers, tomatoes, corn, alfalfa and small grains are the main crops. Natural vegetation is soft chess, wild oats, ripgut brome, turkey mullein and other annual grasses, forbs and scattered valley oaks.
DISTRIBUTION AND EXTENT: Jacktone soils occur in the northern San Joaquin and southern Sacramento Valleys. The soils are not extensive in MLRA-17.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Sutter County, California 1983.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to a depth of 22 inches (Ap, Bss).
Duripan - the zone from 34 to 60 inches (2Bqkm,2Bqk,3Bqk).
Series reclassified on September, 1994. Competing series not reviewed at that time.