LOCATION REEFRIDGE CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Chromic Haplotorrerts
TYPICAL PEDON: Reefridge clay, on a west facing slope of 7 percent under red brome, tomcat clover, and redstem filaree at 775 feet elevation. (Colors are for dry soil unless otherwise stated. When described on 3/4/75 the soil was slightly moist from 0 to 6 inches. Vertical cracks extended from the surface to a depth of 48 inches. Width of cracks varies from 1 inch wide in the upper part and 1 to 2 mm wide at 48 inches.
A11--0 to 1 inches; brown (10YR 5/3) clay, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure parting to strong medium granular; very hard, firm, very sticky and very plastic; many very fine roots; many very fine interstitial pores; neutral (pH 7.3); abrupt smooth boundary. (1 to 2 inches thick)
A12--1 to 5 inches; light yellowish brown (2.5Y 6/4) clay, olive brown (2.5Y 4/4) moist; strong medium subangular blocky structure; very hard, firm, very sticky and very plastic; many very fine roots; many very fine tubular pores; neutral (pH 7.3); abrupt smooth boundary. (4 to 28 inches thick)
A13--5 to 14 inches; light yellowish brown (2.5Y 6/4) clay, olive brown (2.5Y 4/4) moist; strong medium subangular blocky structure; very hard, firm, very sticky and very plastic; common very fine roots; many very fine and few fine tubular pores; few intersecting slickensides; neutral (pH 7.3); abrupt smooth boundary. (0 to 9 inches thick)
C1--14 to 16 inches; light olive brown (2.5Y 5/4) clay, olive brown (2.5Y 4/4) moist; few fine prominent reddish yellow (7.5YR 6/6) mottles, strong brown (7.5YR 5/6) moist; strong coarse prismatic structure; very hard, very firm, very sticky and very plastic; common very fine roots; many very fine and few fine tubular pores; slightly effervescent, disseminated lime; moderately alkaline (pH 8.0); abrupt smooth boundary, (2 to 26 inches thick)
C2cacs--16 to 46 inches; light olive brown (2.5Y 5/4) clay, olive brown (2.5Y 4/4) moist; common medium distinct brownish yellow (10YR 6/8) mottles, yellowish brown (10YR 5/8) moist; strong coarse prismatic structure; very hard, very firm, very sticky and very plastic; few very fine roots; many very fine and few fine tubular pores; violently effervescent, lime disseminated and in common fine seams; common fine gypsum; moderately alkaline (pH 8.0); clear smooth boundary. (0 to 34 inches thick)
C3r--48 inches; variegated light olive gray (5Y 6/2), olive yellow (2.5Y 6/6), and yellow (10YR 7/8) interbedded calcareous shale and sandstone.
TYPE LOCATION: Kings County, California; southern end of Reef Ridge, about 1/8 mile northwest of Hwy. 41; approximately 700 feet west and 1,485 feet north of the SE corner of sec. 1, T. 24 S., R. 17 E. MDB&M.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact composed of shale or interbedded shale and sandstone ranges from 40 to 60 inches. Vertical cracks extend from the surface and range from 1 to 5 centimeters wide at a depth of 50 centimeters. The cracks usually close in January or February for less than 60 consecutive days and remain open the rest of the year. Few to many intersecting slickensides oclcur in some horizon below a depth of 10 inches. The mean annual soil temperature ranges from 65 degrees to 68 degrees F.
The A horizon has dry color of 10YR 4/3 5/3, 5/2; or 2.5Y 6/4 and moist color of 10YR 3/3, 4/3, 4/2; or 2.5Y 4/4. In some pedons the surface horizon has value of 3 moist, but it is less than 2 inches thick. The A horizon has strong fine or medium granular, strong coarse or very coarse prismatic, or moderate or strong medium or coarse subangular blocky structure. It is neutral to moderately alkaline.
The C horizon has dry color of 10YR 4/2, 5/3, 5/2; or 2.5Y 5/4 and moist color of 10YR 4/2, 4/3; or 2.5Y 4/4. Mottles are few to many, fine or medium distinct or prominent and have moist color of 7.5YR 5/6, 6/8; or 10YR 5/8. The mottles are considered to be relict mottles. This horizon is clay or clay loam and averages 35 to 60 percent clay. Rock fragments, ranging in size from 2 mm to 3 inches, are 0 to 5 percent. This horizon has strong coarse or very coarse prismatic or strong coarse subangular blocky structure. It is slightly effervescent to violently effervescent. Lime is disseminated and in seams or soft masses. Electrical conductivity of this horizon ranges from 4 to 8 mmhos.
COMPETING SERIES: These are the Armijo and Dalby series in the same family and the Montoya series. Armijo and Dalby soils are intermittently moist in the moisture control section during the period of June through September. Also, the Dalby soils have hue redder than 10YR. Montoya soils have moist color value of less than 4 in the surface horizon, or in more than the upper 12 inches have moist color value of less than 4. In addition, Armijo and Montoya series lack any paralithic contact within a depth of 60 inches.
GEOGRAPHIC SETTING: Reefridge soils occur on uplands at elevations of 700 to 2,000 feet. They formed in material weathered from shale and sandstone. Slopes are 5 to 30 percent. The climate is arid, with hot, dry summers and temperature is 47 degrees F., and the mean July temperature is 84 degrees F. The mean annual temperature is 64 degrees F. The frost-free season varies from 230 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Delgado, Kettleman, Mercey and Panoche soils. Delgado soils are 7 to 20 inches deep to a lithic contact. Kettleman and Panoche soils are fine-loamy. Mercey soils have a fine-silty particle-size control section.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; slow permeability.
USE AND VEGETATION: This soil is used for cattle and sheep grazing during the late winter and spring. Natural vegetation is annual grasses and forbs.
DISTRIBUTION AND EXTENT: Kreyenhagen Hills, Tent Hills and Reef Ridge in the west-central part of the San Joaquin Valley. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Kings County, California, 1980.