LOCATION HORNITOS CAEstablished Series
TAXONOMIC CLASS: Loamy, mixed, active, thermic Lithic Dystroxerepts
TYPICAL PEDON: Hornitos fine sandy loam - annual grass pasture (Colors for dry conditions unless otherwise noted).
A1--0 to 9 inches; Pale brown (10YR 6/3) fine sandy loam, dark brown (10YR 4/3) moist; massive; slightly hard, very friable; numerous fine grass roots and pores; strongly acid (pH 5.0); clear smooth boundary. (2 to 10 inches thick).
B2--9 to 14 inches; Reddish yellow (7.5YR 6/6) fine sandy loam, strong brown (7.5YR 5/6) moist; massive; slightly hard, very friable; numerous fine grass roots and pores; strongly acid (pH 5.0) ; abrupt irregular boundary. (2 to 12 inches thick).
R--14 inches +; Banded pale yellow (2.5Y 7/4) and strong brown (7.5YR 5/6) massive softly consolidated sandstone of Ione formation that is somewhat softened and weathered in upper part but becomes harder and less weathered with increasing depth; very strongly acid.
TYPE LOCATION: Merced County, California, Sec. 3, T.4S., R.14E.
RANGE IN CHARACTERISTICS: The soils have ochric epipedons (massive and hard dry; high values; less than 1% organic matter), cambic horizon and lithic contact at depths of 20 inches or less. The soils are usually moist but dry for 60 consecutive days in most years.
The mean annual soil temperature is 59 degrees to 72 degrees F. Mineralogy is mixed. Depth to sandstone is 4 to 20 inches. Banding of colors in the profiles appears to be a reflection of banding in the parent material. In places a conglomerate may underlie the soil. The A horizon ranges in color from very pale brown, strong brown to light reddish brown; in texture from fine sandy loam to sandy loam and may be gravelly; in reaction from strongly acid to very strongly acid. The A horizon is massive and slightly hard dry. The B horizon ranges in color from very pale brown, olive brown, olive yellow to reddish yellow; in texture from sandy loam to fine sandy loam. Reaction is strongly acid to very strongly acid. The sandstone is moderately to strongly consolidated and becomes harder with increasing depth. Reaction is strongly to very strongly acid.
COMPETING SERIES: There are no competing series in the same family. Similar soils in another order are Cieneba, Pentz, Trigo Amador and Whiterock. These soils lack cambic horizons. The Amador soils overlie rhyolitic tuff at depths of less than 20 inches. The Whiterock soils overlie slate at depths less than 20 inches. Pentz soils overlie andesitic tuff. Trigo soils overlie softly consolidated granitic alluvium.
SETTING: The Hornitos soils occur on gently rolling to steep topography underlain by softly to moderately consolidated sandstone of the Ione formation. They occur at elevations below 900 feet, in a semiarid mesothermal climate with mean annual rainfall of 12 to 18 inches, with hot, dry summers and cool, moist winters. Mean annual temperature is about 62 degrees F., average January temperature about 45 degrees F. and average July temperature about 81 degrees F. Frost-free season averages about 240 days.
PRINCIPAL ASSOCIATED SOILS: These include the Amador, Daulton, Raynor, Redding and Whiterock. Daulton soils are underlain by slate bedrock. Raynor soils are underlain by tuff. Redding soils occur on old high terraces composed of mixed alluvium.
DRAINAGE AND PERMEABILITY: Somewhat excessively to well drained with moderately rapid to rapid permeability and slow to rapid runoff.
USE AND VEGETATION: The soils are used for grazing. Vegetation is annual grasses, forbs and scattered blue oaks.
DISTRIBUTION AND EXTENT: The westernmost edge of the Sierra Nevada footslopes in central California. The soils are moderately extensive (16,000 + acres)
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Merced Area, California, 1953. Source of name is Hornitos, a small community northeast of Merced, California
REMARKS: Classification of the soils in the Merced, Madera, Mariposa, and Eastern Stanislaus Areas appears as follows: The soils in Merced Area, Madera and Mariposa Areas have a cambic horizon and are Dystric Lithic Xerochrepts. The soils in the Eastern Stanislaus Area lack cambic horizons and range in reaction from slightly to strongly acid. The type location is in a nonacid family. These soils are Lithic Xerorthents, loamy, mixed, nonacid, thermic family. The soils were formerly classified in the Lithosol group.
OSED scanned by SSQA. Last revised by state on 11/67.