LOCATION LAVEAGA CAEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, mesic Typic Argixerolls
TYPICAL PEDON: Laveaga sandy clay loam - on a northwest slope of 45 percent, under blue oak, wild oats, soft chess, filaree, and other annual grasses and forbs at an elevation of 1,940 feet. (Colors are for dry soil unless otherwise stated. When described on June 9, 1982, the soil was slightly moist below 11 inches.)
A1--0 to 9 inches; dark brown (10YR 3/3) and dark yellowish brown (10YR 4/4) sandy clay loam, very dark grayish brown (10YR 3/2) and dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; very hard, friable, slightly sticky and plastic; few very fine and fine roots; common very fine tubular pores; 2.2 percent organic matter; 23 percent clay content; 82 percent base saturation (sum of cations); neutral (pH 7.0); clear smooth boundary.
A2--9 to 18 inches; dark brown (10YR 3/3) and dark yellowish brown (10YR 4/4) sandy clay loam, very dark grayish brown (10YR 3/2) and dark yellowish brown (10YR 3/4) moist; moderate medium prismatic structure parting to moderate medium angular blocky; hard, friable, sticky and plastic; few very fine and common fine, medium, and coarse roots; common very fine and fine tubular pores; 0.6 percent organic matter; 28 percent clay content; 85 percent base saturation (sum of cations); neutral (pH 7.0); abrupt irregular boundary. (Combined thickness of the A horizon is 10 to 22 inches thick)
Bt1--18 to 24 inches; strong brown (7.5YR 5/6) sandy clay, brown (7.5YR 4/4) moist; moderate medium prismatic structure; hard, firm, sticky and very plastic; few very fine and common fine, medium, and coarse roots; common very fine and fine tubular pores; many thick clay films on peds; 37 percent clay content; 94 percent base saturation (sum of cations); moderately acid (pH 6.0); clear wavy boundary.
Bt2--24 to 27 inches; strong brown (7.5YR 5/6) and reddish yellow (7.5YR 6/6) sandy clay, strong brown (7.5YR 4/6, 5/6) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; few very fine and common fine and medium roots; common very fine tubular pores; common moderately thick clay films on peds; 38 percent clay content; moderately acid (pH 6.0); clear wavy boundary. (Combined thickness of the B2t horizon is 8 to 16 inches thick)
BC--27 to 48 inches; brown (7.5YR 5/4) and strong brown (7.5YR 5/6) sandy loam brown (7.5YR 4/4) and strong brown (7.5YR 4/6) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine and common fine and medium roots; few very fine tubular and interstitial pores; few thin clay films on peds and bridging sand grains; 18 percent clay content; moderately acid (pH 6.0); clear smooth boundary. (10 to 25 inches thick)
Cr--48 to 60 inches; brownish yellow (10YR 6/6) and yellow (10YR 8/6) strongly weathered andesitic flow material that crushes to loam; light yellowish brown (10YR 6/4) moist; slightly acid (pH 6.2).
TYPE LOCATION: Merced County, California; about 21 miles WSW of the city of Los Banos, 4,200 feet south of North Fork of Los Banos Creek, 400 feet north of dirt road, 2,400 feet east and 800 feet south of the NW corner of section 3, T. 12 S., R. 7 E.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact is 40 to 60 inches. The moisture control section of 6 to 18 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 57 degrees to 59 degrees F. Typically, cobbles and stones range from 0 to 5 percent in the profile but some pedons have up to 10 percent cobbles and stones in the A horizon with 3 to 15 percent stones on the surface. Organic matter ranges from 1 to 3 percent in the upper 10 inches. Base saturation (sum of cations) is above 75 percent and reaction is moderately acid to neutral throughout.
The A horizon is 7.5YR 5/2, 5/4; 10YR 3/3, 4/3, 4/4, or 5/3. Moist colors are 7.5YR 3/2, 3/4; 10YR 3/2, 3/3, or 3/4. Chromas of 4, moist, occur in mixed colors and are of minor extent. It is sandy clay loam or clay loam and may be very stony clay loam in the upper part. It has 20 to 35 percent clay content.
The Bt horizon is 7.5YR 5/4, 5/6, or 6/6. Moist colors are 7.5YR 4/4, 4/6, or 5/6. It is sandy clay, clay, or clay loam with 35 to 45 percent clay content.
The BC horizon is 5YR 5/4; 7.5YR 5/4, 5/6, or 5/8. Moist colors are 5YR 4/4, 4/6; 7.5YR 4/4 or 4/6. It is sandy loam, loam, or sandy clay loam with 15 to 28 percent clay content.
COMPETING SERIES: These are the Gridley, Gonzaga, and Yorkville soils in other families. These soils are thermic. In addition, Gonzaga soils have an abrupt A/B boundary with over 15 percent clay increase and Yorkville soils occur on fault gouge material and are high in chlorite and Gridley soils are less than 2 percent slopes.
GEOGRAPHIC SETTING: Laveaga soils are on hillslopes in mountains and have slopes of 30 to 75 percent. These soils occur on slopes with northern aspects and have dense stands of oak. Elevations range from 1,100 to 3,300 feet. The soils formed in material in material weathered from andesitic flows and agglomerates of the Quien Sabe Formation. The climate is subhumid with warm dry summers and cool moist winters. The mean annual precipitation is about 15 to 24 inches. Mean January temperature is 42 degrees F; mean July temperature is 71 degrees F; the mean annual temperature is about 59 degrees F. The frost-free season is 190 to 230 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ararat, Peckham, and Quinto soils. These soils are thermic. In addition, Ararat soils are loamy-skeletal and lack an argillic horizon. Peckham soils are loamy-skeletal, 20 to 30 inches thick and lack a mollic epipedon. Quinto soils are less than 20 inches deep.
DRAINAGE AND PERMEABILITY: Well drained, medium to rapid runoff, slow permeability.
USE AND VEGETATION: These soils are used as annual range and upland wildlife habitat. The vegetation is blue oak, white oak, wild oats, soft chess, bluegrass, lupine, ripgut brome, foxtail fescue and other trees, shrubs, and annual grasses and forbs. The tree canopy is typically more than 50 percent.
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.
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).
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 8/84.