LOCATION ARARAT CAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, thermic Pachic Ultic Haploxerolls
TYPICAL PEDON: Ararat extremely stony loam on east-facing slope of 9 percent under oaks, shrubs, annual grasses and forbs at an elevation of 1,720 feet. (Colors are for dry soil unless otherwise stated. When described on September 21, 1981, the soil was slightly moist below 24 inches).
A--0 to 7 inches; brown (10YR 4/3) extremely stony loam, dark brown (7.5YR 3/2) moist; moderate medium and coarse subangular blocky structure; slightly hard, friable, sticky and slightly plastic; common very fine roots; common very fine, few fine and medium tubular pores; 15 percent stones, 5 percent cobbles, and 5 percent boulders; 2.0 percent organic matter; medium acid (pH 6.0); clear smooth boundary. (5 to 14 inches thick)
AB--7 to 24 inches; ;reddish brown (5YR 4/3) very stony loam, dark reddish brown (5YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine, fine and few medium roots; few very fine, common fine and medium tubular pores; 40 percent stones and cobbles; 1.2 percent organic matter; slightly acid; (pH 6.5); gradual smooth boundary. (12 to 25 inches thick)
Bt--24 to 45 inches; reddish brown (5YR 4/3) extremely stony sandy clay loam; dark reddish brown (5YR 3/3) moist; massive; slightly hard, friable, sticky and plastic; few fine, medium and coarse roots; few fine and medium tubular pores; few moderately thick clay films in pores and bridge sand grains; 65 percent stones and cobbles; 0.4 percent organic matter; neutral (pH 7.0); abrupt smooth boundary. (8 to 25 inches thick)
2R--45 inches; fractured volcanic tuff conglomerate.
TYPE LOCATION: Merced County, California, about 20 miles SW of the city of Los Banos, 1.7 miles SE of Pfeiffer ranch house, 375 feet west of dirt road, 2,800 feet west and 2,300 feet south of the NE corner of section 29, T. 12 S.; R. 8 E. (projected section lines from section 5, T. 13 S., R. 8 E.)
RANGE IN CHARACTERISTICS: Depth to volcanic tuff conglomerate is 40 to 50 inches. The moisture control section of o8 to 24 inches is moist throughout from about November 15 to June 1 and dry throughout from about July 1 to October 15 in most years. The soil temperature is below 47 degrees F from December 15 to March 15. The mean annual soil temperature is 59 degrees to 64 degrees F. Stones and boulders cover up 15 to 30 percent of the soil surface. Organic matter ranges from 1 to 4 percent in the upper 20 inches. Some pedons have a thin C horizon. Base saturation (sum of cations) ranges from 50 to 75 percent throughout to at least a depth of 30 inches.
The A horizon is 5YR 4/3; 7.5YR 5/2, 5/3, 5/4; 10YR 4/2, 4/3, 5/2, 5/3, or 5/4. Moist colors are 5YR 3/3; 7.5YR 3/2; 10YR 3/2, or 3/3. It is extremely stony loam in the upper part and very stony loam, very bouldery loam, or very stony sandy clay loam in the lower part with 16 to 26 percent clay content. It has 15 to 30 percent cobbles, stones, and boulders, and 0 to 5 percent gravel. Reaction is medium acid or slightly acid.
The Bt horizon is 5YR 4/3; 7.5YR 4/3, 4/4, 5/4; 10YR 4/3, 5/2, or 5/3. Moist colors are 5YR 3/3; 7.5YR 3/2, 3/4; 10YR 3/3, or 4/2. It is stony sandy clay loam, bouldery sandy clay loam, or stony loam and is modified by very or extremely with 18 to the Bt horizon is less than 1.2 times. It has 50 to 75 percent cobbles, stones, and boulders and 0 to 5 percent gravel. Reaction is slightly acid or neutral.
COMPETING SERIES: There is no other series in the family. Santa Lucia series occurs in another family. Santa Lucia series are 20 to 40 inches deep and are clayey-skeletal.
GEOGRAPHIC SETTING: Ararat soils are on mountain hillslopes and have slopes of 8 to 75 percent. Elevations range from 800 to 3,800 feet. The soils formed in material weathered from volcanic tuff conglomerate of the Quien Sabe Formation. Stones and boulders occupy 15 to 30 percent of the surface. The climate is semi-arid with warm dry summers and cool moist winters. The mean annual precipitation is about 15 to 24 inches. Mean January temperature is 44 degrees F; mean July temperature is 72 degrees F; and mean annual temperature is 61 degrees F. Frost-free season is 190 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Franciscan, Gilroy, Laveaga, Peckham, and Quinto soils. Franciscan and Gilroy soils are 20 to 40 inches deep, fine-loamy, and have an argillic horizon. Laveaga soils are fine textured and have a mesic temperature regime. Peckham soils are 20 to 40 inches deep and have an argillic horizon. Quinto soils are less than 20 inches deep.
DRAINAGE AND PERMEABILITY: Well drained, medium to rapid runoff, moderately slow permeability.
USE AND VEGETATION: These soils are used as annual rangeland and upland wildlife habitat and watershed. The vegetation is blue oak, white oak, and live oak, soft chess, wild oats, and ripgut brome and shrubs.
DISTRIBUTION AND EXTENT: These soils are in the Coast Range of California. They are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Merced County, California, 1983.
REMARKS: These soils were formerly mapped as Rough stony land in the Los Banos area, series 1939 report. pH determined by colorimetric method using Thymol Blue and Hellige Truog triplex indicators. Texture determined by hydrometer method. Organic carbon determined by Walkley-Black digestion method. Base saturation determined by KC1-triethanolamine extract (sum of cations).
Last revised by the state on 8/84.