LOCATION UXO CA
Established Series
REV LJL/PBF/ET
12/2015
UXO SERIES
The Uxo series consists of very deep, well drained soils that formed in alluvium from granite. Uxo soils are on alluvial fans and fan aprons. Slopes range from 2 to 8 percent. The mean annual precipitation is about 5 inches and the mean annual air temperature is about 64 degrees F.
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, nonacid, thermic Typic Torriorthents
TYPICAL PEDON: On Venusite-Uxo association, 2 to 15 percent slopes at an elevation of 3,760 feet. (Colors are for dry soil unless otherwise noted.) The surface is covered by approximately 70 percent gravel.
A -- 0 to 2 inches; pale brown (10YR 6/3) extremely gravelly sandy loam, brown (10YR 4/3) moist; moderate thick and very thick platy structure; moderately hard, very friable, slightly sticky and nonplastic; few very fine and fine roots; few very fine and fine tubular pores; noneffervescent; 70 percent gravel; slightly alkaline (pH 7.6); clear smooth boundary. (2 to 4 inches thick)
C1 -- 2 to 10 inches; light yellowish brown (10YR 6/4) gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; massive; hard, very friable, slightly sticky and nonplastic; common very fine and few fine roots; few very fine through medium tubular pores; noneffervescent; 20 percent gravel; slightly alkaline (pH 7.8); gradual smooth boundary.
C2 -- 10 to 17 inches; yellowish brown (10YR 5/4) gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; massive; moderately hard, very friable, slightly sticky and nonplastic; common very fine, few fine and medium roots; common very fine interstitial and few fine tubular pores; noneffervescent; 30 percent gravel; slightly alkaline (pH 7.8); clear smooth boundary. (Combined thickness of the C horizon is 15 to more than 45 inches)
Btk -- 17 to 60 inches; yellowish brown (10YR 5/6) gravelly sandy loam, dark yellowish brown (10YR 4/6) moist; massive; hard, friable, slightly sticky and nonplastic; few very fine roots; common very fine interstitial and few fine tubular pores; 10 percent faint patchy clay films on sand and gravel and lining pores; 3 percent soft seams of lime; strongly effervescent; 25 percent gravel; moderately alkaline (pH 8.2).
TYPE LOCATION: San Bernardino County, California; approximately 15 miles north-northeast of the cantonment area, Fort Irwin National Training Center, and one mile north of Granite Pass; about 3,300 feet south and 700 feet east of the northwest corner of tentative section 27, T. 16 N., R. 4 E.; 35 degrees, 26 minutes, 36 seconds north latitude and 116 degrees, 32 minutes, 44 seconds west longitude; Drinkwater Lake, Calif. 7.5 minute quadrangle; UTM 11S, 0541235e 3922116n (DTM:NAS-C).
RANGE IN CHARACTERISTICS:
Soil moisture control section - usually dry, moist in some part for short periods during winter and early spring and for 10 to 20 days cumulative between July and October following convection storms. The soils have a Typic-Aridic moisture regime.
The soil surface is covered with 65 to 85 percent gravel, 0 to 2 percent cobbles, and 0 to 2 percent stones.
Soil temperature: 63 to 68 degrees F.
Organic matter: 0 to 0.5 percent.
Control section -
Rock fragments: 15 to 30 percent gravel, with 50 to 85 percent in the 2 to 5 millimeter size fraction.
Clay content: 8 to 15 percent.
Effervescence: noneffervescent to a depth of 15 inches or more.
A horizon
Value: 5 or 6 dry, 3 to 5 moist
Chroma: 3 or 4 dry
Texture of the fine earth: coarse sandy loam or
sandy loam
Clay content: 8 to 12 percent
Rock fragments: range is 40 to 75 percent; with 40 to
75 percent gravel, 0 to 1 percent cobbles, and 0 to 1
percent stones
-Reaction: neutral or slightly alkaline
C horizon
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 4 to 6 moist
Texture of the fine earth: coarse sandy loam or sandy loam
Clay content: 8 to 15 percent
Rock fragments: 15 to 30 percent; with 15 to
30 percent gravel, 0 to 1 percent cobbles, and 0 to 1
percent stones
Effervescence: noneffervescent to strongly effervescent
Calcium carbonate equivalence: 0 to 5 percent
Reaction: neutral to moderately alkaline
Btk horizon (where present)
Value: 5 to 7 dry, 4 or 5 moist
Chroma: 4 to 6, dry or moist
Texture of the fine earth: coarse sandy loam or sandy loam
Clay content: 8 to 12 percent
Rock fragments: 15 to 30 percent gravel
Effervescence: noneffervescent to strongly effervescent
Calcium carbonate equivalence: 1 to 5 percent
Reaction: slightly or moderately alkaline
Other features: few or common, thin patchy or
discontinuous clay films
COMPETING SERIES: These are the
Cantua (CA),
Wasco (CA) and
Yana (NM) series. Cantua soils have soft weathered sandstone at 40 to 60 inches. Cantua and Wasco soils have a moisture control section that is moist in some part more than half the time, cumulative, that the soil temperature at 20 inches is greater than 41 degrees F., and 0 to 15 percent rock fragments in the particle-size control section. Yana soils are moist in some part of the soil moisture control section for more than 20 days cumulative between July and September.
GEOGRAPHIC SETTING: Uxo soils are on alluvial fans and fan aprons. Slopes are 2 to 8 percent. These soils formed in alluvium from granite. Elevations are 3,400 to 4,200 feet. The climate is arid with hot, dry summers and warm, moist winters. The mean annual precipitation is 4 to 7 inches; mean annual air temperature is 61 to 66 degrees F., and the frost-free season is 240 to 300 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Venusite soils. Venusite soils have a loamy-skeletal particle-size control section.
DRAINAGE AND PERMEABILITY: Well drained; very low or low runoff; moderately rapid permeability.
USE AND VEGETATION: Uxo soils are used for military exercises and wildlife habitat. The present vegetation is mainly creosotebush, blackbrush, California buskwheat, desert needlegrass, and white bursage.
DISTRIBUTION AND EXTENT: Mojave Desert of southeastern California. MLRA 30. These soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA
SERIES ESTABLISHED: San Bernardino County, California, Fort Irwin Soil Survey Area, 1998. The name is coined.
REMARKS: Diagnostic horizons and features recognized in the profile are:
1. Ochric epipedon -- 0 to 2 inches (A horizon).
2. Particle size control section -- 10 to 40 inches (C2 and
part of the Btk horizons).
3. Other features -- clay does not increase enough in the
Btk horizon to qualify as an argillic horizon.
Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 6/2000. ET
National Cooperative Soil Survey
U.S.A.