LOCATION ARRASTRE CAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Typic Haploxerepts
TYPICAL PEDON: Arrastre sandy loam. (Colors are for dry soil unless otherwise stated.)
A1--0 to 6 inches; brown (10YR 5/3) sandy loam, dark brown (10YR 4/3) moist; moderate very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, few fine roots; common very fine interstitial pores; about 10 percent by volume gravel (1/4 to 3/8 inches); slightly acid (pH 6.5); clear smooth boundary. (4 to 6 inches thick)
A2--6 to 17 inches; brown (10YR 5/3) gravelly sandy loam, dark brown (10YR 4/3) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, few fine and medium roots; common very fine, few fine and medium roots; common very fine interstitial pores; about 20 percent by volume gravel (3/8 inches); slightly acid (pH 6.5); gradual wavy boundary. (7 to 13 inches thick)
Bt--17 to 26 inches; yellowish brown (10YR 5/4) gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; moderate medium and coarse subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine, few coarse and medium roots; common very fine interstitial, few very fine tubular pores; about 20 percent by volume gravel (1/4 to 3/8 inches); few thin clay films between mineral grains; slightly acid (pH 6.5); abrupt wavy boundary. (9 to 21 inches thick)
R--26 inches; hard shattered and broken granitic rock which does not slake in water; fractures are spaced at 10 to 30 cm intervals and are nearly devoid of soil material; rock fragments have not been displaced.
TYPE LOCATION: San Bernardino County, California; on Grapevine Canyon Road about 1.4 miles north of Microwave Station; NW1/4 NW1/4 NE1/4 section 3, T.4N., R.2W.
RANGE IN CHARACTERISTICS: Depth to a lithic contact of hard granitic rock ranges from 20 to about 40 inches. The mean annual soil temperature is estimated to be 54 to 59 degrees F. The soil between the depths of 8 and 24 inches usually is moist in all parts from early December until late February or mid-March. It is usually moist in some part between depths of 8 and 24 inches from late November until June and is continuously dry the rest of the time. The solum includes 10 to 25 percent gravel. It is slightly acid or neutral throughout. Base saturation ranges from 75 to 90 percent. Organic matter is less than 1 percent in the A horizon.
The A horizon is brown or light yellowish brown (10YR 5/3, 6/4). Moist colors are brown or yellowish brown (10YR 4/3, 5/4). This horizon is typically sandy loam but ranges to gravelly sandy loam and gravelly loamy sand.
The Bt horizon is yellowish brown, brown, or reddish yellow (10YR 5/4, 5/6, 5/3; 7.5YR 6/6, 6/8). It is gravelly sandy loam or sandy loam and averages 7 to 14 percent clay. Increase in clay ranges from 0 to 2 percent.
Some pedons have a C horizon. It is yellowish brown or light yellowish brown (10YR 5/4, 5/6, 6/4) neutral, loamy sand. It is massive and has 10 to 30 percent fine gravel.
COMPETING SERIES: These are the Barron, Bestrom (T), Clayton, Dipper (T), Frailey, Green Bluff, Koerling, Scala, Siskiyou and Stoner series. All of these soils except Bestrom lack a lithic contact within a depth of 40 inches. Bestrom soils have a mean annual soil temperature of 47 to 51 degrees F. Also, Barron soils are medium acid throughout and Clayton soils have thin A2 horizons and thin bands of loam in the control section. Green Bluff soils are loam, fine sandy loam or silt loam and have a mean annual soil temperature less than 54 degrees F. Koerling soils have secondary carbonates within a depth of 43 inches and have a mean annual soil temperature less than 54 degrees F. Siskiyou soils have a paralithic contact at a depth of 20 to 40 inches.
GEOGRAPHIC SETTING: Arrastre soils are on uplands and have gradients of 30 to 50 percent. They formed in residuum from granddiorite, granite, and other granitic rocks. Arrastre soils are commonly found in association with rock outcrop. Elevations are 4,100 to 5,000 feet. The climate is subhumid mesothermal having warm, dry summers and cool, moist winters. The mean annual precipitation is 14 to 18 inches of which 1/2 falls as snow of short duration. The average January temperature is 40 to 42 degrees F.; the average July temperature is 66 to 70 degrees F.; and the mean annual temperature is 54 to 58 degrees F. The frost free season is about 160 to 190 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Crafton, Cushenbury and Tollhouse soils. Crafton and Cushenbury soils have a mollic epipedon and have a paralithic contact at a depth of 20 to 40 inches. Tollhouse soils have a mollic epipedon and have a paralithic contact at a depth of less than 20 inches.
DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; moderately rapid permeability.
USE AND VEGETATION: Used mainly for wildlife habitat and for dryland pasture. Native vegetation is annual grass, forbs, yucca and scattered clumps of California juniper.
DISTRIBUTION AND EXTENT: Foothills of the San Bernardino Mountains near Grapevine Canyon. The soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: San Bernardino County, Mojave River Area, California, 1978.
REMARKS: This soil has an ochric epipedon because the moist colors are 10YR 4/3.
ADDITIONAL DATA: Reference sample for organic carbon. Pedon number 573-CALIF-36-13.