LOCATION OCRAIG CAEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, nonacid, thermic Lithic Xerorthents
TYPICAL PEDON: Ocraig gravelly coarse sandy loam - on a mountainside of about 60 percent slope under soft chess and wild oats at 1,060 feet elevation. (Colors are for dry soil unless otherwise stated. When described on July 17, 1980, the soil was dry throughout.)
A--0 to 2 inches; brown (10YR 5/3) gravelly coarse sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine roots; many very fine interstitial and common very fine tubular pores; 20 percent pebbles; neutral (pH 7.0); clear smooth boundary. (1 to 3 inches thick)
C--2 to 8 inches; pale brown (10YR 6/3) gravelly coarse sandy loam, dark brown (10YR 3/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; common very fine tubular pores; 20 percent pebbles; neutral (pH 7.0); clear smooth boundary. (3 to 7 inches thick)
R--8 inches; light gray (10YR 7/1) hard fractured coarse grained andesite.
TYPE LOCATION: Sutter County, California; approximately 1/2 mile below South Butte Summit on Summit Road; 700 feet west of the northwest corner of section 36, T. 16 N., R. 1 E.
RANGE IN CHARACTERISTICS: Depth to a lithic contact ranges from 4 to 10 inches. The mean annual soil temperature is 60 degrees to 64 degrees F. The soil moisture at the lithic contact is dry from May 1 to October 31, and is moist from November 1 to April 30. The difference between average July and average January temperature is 30 degrees to 33 degrees F. Rock fragments range from 15 to 35 percent. Stones range from 0 to 20 percent, cobbles from 0 to 5 percent and gravel from 15 to 30 percent. Clay content ranges from 5 to 15 percent. The soil is gravelly coarse sandy loam or very stony coarse sandy loam. Very coarse sand plus coarse sand is greater than 20 percent.
The C horizon has dry color of 10YR 6/3 or 5/4 and moist color of 10YR 3/3 or 4/4.
COMPETING SERIES: These are the Daulton, Exchequer and Gaviota series and the Amador, Hillbrick, and Whiterock series in other families. Daulton soils have bedrock at depths greater than 10 inches. Amador and Whiterock soils are strongly or very strongly acid. Hillbrick soils are effervescent in all horizons. Exchequer soils have clay contents of 15 to 25 percent. Gaviota soils have less than 20 percent very coarse and coarse sand and are 6 to 20 inches deep.
GEOGRAPHIC SETTING: Ocraig soils are on mountains. Slopes are 30 to 75 percent. The soils formed in material weathered from extrusive igneous rock, mainly andesite and some rhyolite. Elevations are 500 to 2,100 feet. The climate is subhumid with hot dry summers and cool moist winters. Mean annual precipitation is 16 to 19 inches. Mean January temperature is 45 degrees F., mean July temperature is 77 degrees F., and mean annual temperature varies from 58 degrees to 62 degrees F. Frost-free season varies from 250 to 270 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Palls and Stohlman soils. Palls and Stohlman soils are on lower and less sloping mountainsides. Palls soils have bedrock at 20 to 40 inches. Stohlman soils have bedrock at 10 to 20 inches and have an argillic horizon.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; rapid to very rapid runoff; moderately rapid permeability.
USE AND VEGETATION: This soil is used for watershed and wildlife habitat. Characteristic vegetation is wild oats, soft chess, and California scrub oak.
DISTRIBUTION AND EXTENT: Sutter Buttes area of the Sacramento Valley. Soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Sutter County, California 1983. Series name was coined.
REMARKS: The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET
OSED scanned by SSQA. Last revised by state on 2/84.