LOCATION ASOLT CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Chromic Haploxererts
TYPICAL PEDON: Asolt very stony clay - on a southwest facing slope of 30 percent under wild oats and other grasses and forbs, at an elevation of 1,400 feet. (Colors are for dry soil unless otherwise stated. When described, August 12, 1981 the soil was dry to 29 inches and slightly moist below.)
A1--0 to 3 inches; dark reddish gray (5YR 4/2) very stony clay, dark reddish brown (5YR 3/3) moist; strong medium and coarse subangular blocky structure; hard, friable, sticky and plastic; common very fine roots; few very fine tubular pores; 47 percent clay content; 20 percent cobbles and 10 percent stones; slightly effervescent with disseminated lime; organic matter is 2.2 percent; moderately alkaline (pH 8.0); clear wavy boundary (1 to 5 inches thick)
A2--3 to 20 inches; dark reddish brown (5YR 3/2) cobbly clay, dark reddish brown (5YR 3/3) moist; strong coarse and very coarse angular blocky and prismatic structure; very hard, friable, sticky and very plastic; many very fine roots concentrated along vertical faces of peds; few very fine tubular pores; 57 percent clay content; 20 percent cobbles and 10 percent stones; slightly effervescent with disseminated lime; organic matter is 1.8 percent; moderately alkaline (pH 8.0); clear wavy boundary. (15 to 22 inches thick)
A3--20 to 29 inches; dark reddish gray (5YR 4/2) cobbly clay, reddish brown (5YR 4/3) moist; strong coarse and very coarse prismatic structure; very hard, friable, sticky and very plastic; few very fine roots; common very fine tubular pores; 60 percent clay content; 20 percent cobbles and 10 percent stones; strongly effervescent with disseminated lime; moderately alkaline (pH 8.0); clear irregular boundary. (7 to 15 inches thick)
C--29 to 42 inches; brown (7.5YR 5/4) cobbly clay, brown (7.5YR 4/4) moist; moderate coarse subangular blocky structure; very hard, friable, sticky and plastic; no roots; few very fine tubular pores; 59 percent clay content; 20 percent cobbles and 10 percent stones; common moderately thick pressure faces; violently effervescent with disseminated lime; moderately alkaline (pH 8.0); clear irregular boundary. (11 to 19 inches thick)
R--42 inches; basalt.
TYPE LOCATION: Merced County, California; about 14 miles west of the city of Los Banos on the southwest side of Basalt Hill, 2,300 feet west and 1,200 feet north of the SE corner of Section 33, T.10S., R.8E., San Luis Dam Quadrangle.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 59 degrees to 62 degrees F. The soil is warmer than 47 degrees F from January 30 to Decemnber 1. The soil between 8 to 24 inches is moist in all parts from December 1 to May 1 and dry in all parts from July 1 to November 1. Depth to basalt bedrock ranges from 40 to 60 inches. Cracks 1 to 2 cm wide are at a depth of 20 inches; these cracks are 2 to 5 cm wide at the surface. Clay content ranges from 40 to 60 percent. Cobbles and stones range from 20 to 35 percent in the profile. Gravel content ranges from 0 to 5 percent. Reaction is neutral to moderately alkaline. The surface is covered with 0 to 35 percent cobbles and 5 to 15 percent stones.
The A horizon is 5YR 3/2, 4/2, 4/3; 7.5YR 3/4; 10YR 4/1 or 4/2. Moist colors are 5YR 3/2, 3/3, 4/3; 7.5YR 4/4, 4/6; 10YR 3/2 or 4/2. Organic matter ranges from 1 to 3 percent.
The C horizon is 5YR 4/3, 4/4; 7.5YR 5/4 or 5/6. Moist colors are 5YR 3/4, 4/4, 5/3; or 7.5YR 4/4.
COMPETING SERIES: These are the Alo, Altamont, Asbill, Auld, Ayar, Capay, Centerville, Chinapoint, Cibo, Galt, Hollenbeck, Lostpoint, Porterville, Seville series in the same family and the Lecrag and Sehorn series in other families. Alo, Altamont, Auld, Ayar and Sehorn soils have less than 20 percent coarse fragments. Asbill and Chinapoint soils have a paralithic contact within 40 inches. Cibo soils have lithic contact within 40 inches. Galt and Hollenbeck soils have a duripan. Lostpoint soils are saline-alkali. Capay, Centerville, Porterville and Seville soils lack a lithic contact. Lecrag soils are mesic.
GEOGRAPHIC SETTING: Asolt soils are on hill slopes in mountains and have slopes of 15 to 50 percent. Elevations range from 800 to 2,500 feet. These soils formed in material weathered from basalt of the Quien Sabe Formation. The climate is semiarid with hot dry summers and cool moist winters. The mean annual precipitation is 12 to 22 inches. The mean January temperature is 45 degrees F, mean July temperature is 77 degrees F and the mean annual temperature is 61 degrees F. The frost-free season is 190 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Lecrag soils and the Ararat, Oneil and Peckham soils. Ararat soils are loamy-skeletal. Oneil soils are fine-silty. Peckham soils are loamy-skeletal and have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; slow permeability.
USE AND VEGETATION: These soils are used as rangeland and upland wildlife habitat. The vegetation is wild oats, red brome, soft chess, filaree and other annual grasses and forbs.
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 1984. Name is coined.
REMARKS: These soils were formerly mapped as Rough Stony Land in the Los Banos Area, Series 1939 report. They are being differentiated by having deep soil and grass cover. pH determined by colormetric method using Thymol Blue and Hellige-Truog Triplex indicators. Texture determined by hydrometer method. Organic matter estimated by comparing with adjacent soils determined by Walkley-Black digestion method. Presence of lime determined by 10 percent HCl.
Series reclassified June 1996. Competing series not reviewed at that time. Noted lack of slickensides and/or wedge-shaped aggregates in profile.