LOCATION TIBBCREEK CATentative Series
TAXONOMIC CLASS: Loamy, mixed, superactive, frigid, shallow Aridic Argixerolls
TYPICAL PEDON: Tibbcreek series on a west-facing, convex, 13 percent slope under big sagebrush, rubber rabbitbrush, desert bitterbrush cheatgrass, buckbrush and buckwheat. Colors are for dry soil unless otherwise noted. When described (August 8, 1981) the soil was dry throughout.
A--0 to 8 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; moderate medium and coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine and medium roots; few very fine and fine tubular pores; 20 percent angular gravel and 2 percent angular cobbles; neutral (pH 6.8); clear wavy boundary. (5 to 10 inches thick)
Bt--8 to 18 inches; yellowish brown (10YR 5/4) gravelly light clay loam, dark yellowish brown (10YR 4/4) moist; moderate coarse subangular blocky structure; hard, friable, sticky and plastic; few very fine, fine and medium roots; few very fine and fine tubular pores; few thin clay films on faces of peds and common thin clay films bridging mineral grains; 20 percent angular gravel and 2 percent angular cobbles; neutral (pH 6.6); clear irregular boundary. (5 to 12 inches thick)
Cr--18 to 35 inches thick; yellowish brown (10YR 5/4) and highly fractured metasedimentary rock, dark yellowish brown (10YR 4/4) moist; few medium roots in cracks; common thin clay films on surfaces of rock fragments.
R--35 inches; hard, fractured metasedimentary rock.
TYPE LOCATION: Tulare County, California; about 2 miles south-southeast of Bear Mountain; approximately in the NE 1/4 of the SW 1/4 of Section 10, T. 24 S., R. 36 E. (area is not sectionalized); USGS Lamont Peak topographic quadrangle; longitude 118 degrees 5 minutes 9 seconds west and latitude 35 degrees 51 minutes 24 seconds north.
RANGE IN CHARACTERISTICS:
Soil moisture: The soil is usually moist in some part for about 75 days when the soil temperature is above 5 degrees C. It is moist in all parts for 45 or more consecutive days between December and April, but the soil temperatures are below 5 degrees C during this period. The moisture regime is Aridic but it borders on Xeric.
Soil temperature: The mean annual soil temperature is 44 to 47 degrees F.
Rock fragments: 15 to 35 percent gravel and 0 to 5 percent cobbles. Some soil horizons have up to 45 percent gravel but the control section is less than 35 percent.
Depth to bedrock: 10 to 20 inches to soft, fractured metasedimentary rock; 20 to 50 inches to hard fractured rock.
Reaction: slightly acid or neutral
A horizon
Hue: 10YR or 7.5YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3, moist or dry
Texture: gravelly sandy loam or gravelly loam
Clay: 10 to 22 percent
Organic matter: 1 to 2 percent
B horizon
Hue: 10YR or 7.5YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 or 4, moist or dry
Texture: gravelly loam, gravelly clay loam or very
gravelly loam
Clay: 18 to 30 percent
COMPETING SERIES: This is the Hart Camp (NV) series. Hart Camp soils are formed from tuff and are on pediments and plateaus. They occur at elevations of less than 6,500 feet.
GEOGRAPHIC SETTING: Tibbcreek soils are on hilly plateaus and broad ridgetops in mountainous areas with slopes of 5 to 30 percent. Elevations are from 7,500 to 8,200 feet. These soils formed in material weathered from hard, fractured metasedimentary rock. The mean annual precipitation is 12 to 14 inches, mostly as winter snow. Mean annual snowfall is 75 to 100 inches. The mean January temperature is about 27 degrees F; mean July temperature is about 61 degrees F; mean annual temperature is 39 to 47 degrees F. The frost-free season is 60 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Wortley and Indiano soils. Wortley soils contain less than 12 percent clay throughout the profile and have a mean annual soil temperature greater than 47 degrees F. Indiano soils are deeper than 20 inches to soft bedrock and have a mean annual soil temperature greater than 47 degrees F.
DRAINAGE AND PERMEABILITY: Well drained, moderate permeability, medium runoff.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. Much of the acreage of this soil was chained in the 1960's in an attempt to convert the vegetation from pinyon woodland into range grassland. Natural potential plant community is mainly singleleaf pinyon with some western juniper, big sagebrush and desert bitterbrush.
DISTRIBUTION AND EXTENT: High elevations in the southern Sierra Nevada mountains. The soils of this series are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Tulare County; Northeastern Kern Area, California, Parts of Kern and Tulare Counties Soil Survey Area, 1996. The name is adapted from Tibbets Creek.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Mollic epipedon-from a depth of 0 to 8 inches (A horizon).
Argillic horizon-from a depth of 8 to 18 inches (Bt horizon).