LOCATION AVAWATZ CAEstablished Series
TAXONOMIC CLASS: Sandy, mixed, mesic Mollic Xerofluvents
TYPICAL PEDON: Avawatz sandy loam, on a NE facing convex slope of 3 percent under big sagebrush, buckwheat, Joshua tree, Utah juniper and annual grasses at 4,850 feet elevation. (Colors are for dry soil unless otherwise stated. When described the soil was dry throughout.)
A1--0 to 15 inches; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine, few fine roots; few very fine interstitial pores; about 5 percent (1/2 inch) pebbles; neutral (pH 6.8); gradual smooth boundary. (8 to 16 inches thick)
C--15 to 60 inches; pale brown (10YR 6/3) loamy sand, dark brown (10YR 4/3) moist; massive; slightly hard, very friable; few very fine roots; few very fine interstitial pores; fine strata (1/2 to 1 inch) of sandy loam above a 40 inch depth; about 10 percent (1/2 to 2 inch) pebbles; neutral (pH 6.8).
TYPE LOCATION: San Berardino County, California; about 1/2 mile west of Phelan and 1 1/4 mile south in the SE1/4 SW1/4 section 26, T.4N., R.7W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is about 53 to 59 degrees F. The soil between depths of 12 and 35 inches becomes moist in some part from early December to May, is continuously moist for 90 to 120 days when the soil is above 47 degrees F. and is continuously dry the rest of the year. Organic carbon ranges from 0.2 to 0.6 percent.
The A1 horizon is grayish brown, dark brown, or brown (10YR 5/2, 4/3, 5/3). Moist colors are dark brown or very dark grayish brown (10YR 3/3, 3/2). This horizon is sandy loam or loamy sand and averages 5 to 15 percent gravel. It has weak to moderate, fine to medium subangular blocky structure. Base saturation is assumed to be 75 to 100 percent. Reaction is slightly acid or neutral.
The C horizon is brown, pale brown, light yellowish brown, or light brownish gray (10YR 5/3, 6/3, 6/4, 6/2). Moist colors are dark brown , dark yellowish brown or dark grayish brown (10YR 4/3, 4/4, 4/2). This horizon has thin strata of sandy loam between depths of 20 to 40 inches and averages 5 to 15 percent fine gravel.
COMPETING SERIES: These are the Ledow series in the same family and the Danskin, Metz, Mottsville, Newruss and Shaffer series. Ledow soils are usually moist and have a mean annual soil temperature of 47 to 53 degrees F. Danskin soils have a regular decrease in organic matter with increasing depth, are underlain by bedrock at a depth of 40 to 60 inches and have moist value of 4 or more in the A horizon. Metz soils are thermic. Mottsville and Shaffer soils have a mollic epipedon. Newruss soils have a coarse, loamy control section.
GEOGRAPHIC SETTING: Avawatz soils are on alluvial fans and intermittent drainageways at elevations of 3,400 to 5,200 feet. Slopes are 2 to 9 percent. The soils are subject to rare flooding in places. They formed in alluvium from mixed but dominantly granitic sources. The climate is subhumid mesothermal having warm, dry summers and cool, moist winters. The mean annual precipitation is 12 to 14 inches of which about 1/4 to 1/3 falls as snow of short duration. The average January temperature is 42 to 44 degrees F.; the average July temperature is 72 to 74 degrees F.; and the mean annual temperature is 55 to 57 degrees F. The frost free season is about 160 to 190 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bull Trail and Oak Glen soils. Bull Trail soils have a sandy clay loam B2t horizon. Oak Glen soils have a mollic epipedon more than 20 inches thick.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow runoff; rapid permeability.
USE AND VEGETATION: Used mainly for range and wildlife habitat. Vegetation is big sagebrush, Utah juniper, scrub oak, buckwheat, desert needlegrass, rubber rabbitbrush, annual grasses and forbs.
DISTRIBUTION AND EXTENT: Alluvial fans and drainageways of the San Bernardino Mountains adjacent to Mojave Desert. The soils are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: San Bernardino County, California, Mojave River Area, 1978.
REMARKS: Organic carbon determination show this soil has less than 0.6 percent organic carbon and is classified as a ochric epipedon.
ADDITIONAL DATA: Reference sample for organic carbon for a soil just a short distance away. Pedon number 77CA-071-1 and 77CA-071-2.