LOCATION ELOMA                   AZ

Established Series
Rev. SDH
10/2013

ELOMA SERIES

The Eloma series consists of very deep, well drained soils that formed in alluvium from granite and gneiss. Eloma soils are on fan remnants and have slopes of 1 to 65 percent. The mean annual precipitation is about l4 inches (356 mm) and the mean annual air temperature is about 63 degrees F (17.3 degrees C).

TAXONOMIC CLASS: Clayey-skeletal, mixed, superactive, thermic Ustic Haplargids

TYPICAL PEDON: Eloma very cobbly loam - rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 2 inches (0 to 5 cm); brown (10YR 4/3) very cobbly loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine irregular pores; 40 percent cobble and 20 percent gravel; slightly acid (pH 6.5); abrupt smooth boundary. (2 to 3 inches or 5 to 8 cm thick)

Bt1--2 to 5 inches (5 to 13 cm); brown (7.5YR 4/4) very cobbly clay loam, dark brown (7.5YR 3/4) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; many very fine, fine and medium roots; many very fine and fine tubular and irregular pores; common faint clay films on faces of peds; 40 percent cobble and 20 percent gravel; neutral (pH 7.0); clear smooth boundary. (2 to 4 inches or 5 to 10 cm thick)

Bt2--5 to 9 inches (13 to 23 cm); dark reddish brown (5YR 3/4) very gravelly clay, dark reddish brown (5YR 3/4) moist; strong fine and medium subangular blocky structure; slightly hard, friable, very sticky and very plastic; many very fine, fine and medium roots; many very fine and fine tubular and irregular pores; common faint clay films on faces of peds; 40 percent gravel and 20 percent cobble; neutral (pH 7.0); clear wavy boundary. (3 to 6 inches or 8 to 15 cm thick)

Bt3--9 to 22 inches (23 to 56 cm); dark reddish brown (2.5YR 3/4) extremely cobbly clay, dark reddish brown (2.5YR 3/4) moist; strong medium angular blocky structure; hard, friable, very sticky and very plastic; many very fine and fine and common medium roots; common faint clay films on faces of peds and lining pores; 45 percent cobble and 25 percent gravel; neutral (pH 7.0); clear wavy boundary. (11 to l6 inches 28 to 41 cm thick)

Bt4--22 to 34 inches (56 to 86 cm); reddish brown (2.5YR 4/4) extremely cobbly clay, reddish brown (2.5YR 4/4) moist; strong medium angular blocky structure; hard, friable, very sticky and very plastic; many very fine and fine roots; many very fine and fine tubular pores; many distinct clay films on faces of peds and lining pores; 45 percent cobble and 25 percent gravel; slightly alkaline (pH 7.5); clear wavy boundary. (11 to l5 inches or 28 to 38 cm thick)

Bt5--34 to 45 inches (86 to 114 cm); reddish brown (5YR 5/4) extremely cobbly sandy clay, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, very sticky and moderately plastic; common very fine roots; many very fine irregular and common fine tubular pores; common faint clay films on faces of peds and lining pores; 45 percent cobble and 30 percent gravel; slightly alkaline (pH 7.5); abrupt wavy boundary. (11 to l6 inches or 28 to 41 cm thick)

2C--45 to 60 inches (114 cm to 152 cm); light brown (7.5YR 6/4) extremely cobbly sandy loam, brown (7.5YR 4/4) moist; massive; slightly hard, friable, nonsticky and nonplastic; few very fine roots; common very fine irregular pores; 50 percent cobble and 30 percent gravel; moderately alkaline (pH 8.0).

TYPE LOCATION: Graham County, Arizona; about l3 miles southwest of the town of Pima along Tripp Canyon Road, 2,300 feet east and 2,200 feet south of the northwest corner of sec. l8, T. 7 S., R. 23 E. Latitude 32 degrees, 49 minutes, 29 seconds N., longitude 110 degrees, 1 minute, 56 seconds W.

RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some part of the soil moisture control section during July-September and December-February. Driest during May and June. Ustic aridic soil moisture regime.
Soil Temperature: 59 to 70 degrees F. (15 to 21.1degrees C)
Surface fragments: 0 to 80 percent
Solum Thickness: 40 to 60 inches (102 to 152 cm)
Organic Matter: 1 to 2 percent in the surface
Reaction: slightly acid to moderately alkaline

Particle-size control section (weighted average):
Clay content: 35 to 55 percent
Rock fragments: 35 to 90 percent

A horizon
Hue: 5YR, 7.5YR, l0YR
Value: 2.5 to 5, dry or moist
Chroma: 2 to 4, dry or moist

Bt horizon
Hue: 2.5YR, 5YR, 7.5YR
Value: 2.5 to 6, dry or moist
Chroma: 2 to 6, dry or moist
Texture: clay, clay loam, sandy clay, and sandy clay loam. Includes silty clay, sandy clay loam, loam, and silty clay loam in the upper part of the argillic in the Verde Valley area, Arizona.
Calcium carbonate equivalent: may have irregular or soft accumulations in some pedons. Less than 15 percent calcium carbonate equivalent.

C horizon (when present)
Hue: 5YR, 7.5YR
Value: 4 to 6, dry or moist
Chroma: 3 to 6, dry or moist
Texture: sandy loam, sandy clay loam, loam, clay loam, silty clay loam
Calcium carbonate equivalent: 0 to 5 percent

COMPETING SERIES: These are the Pinwheel (T) (AZ) series. Pinwheel soils are moderately deep to sandstone.

GEOGRAPHIC SETTING: Eloma soils are on fan remnants at elevations of 3,000 to 5,540 feet (914 to 1689 meters). These soils formed in alluvium from dominantly granite and gneiss. Slopes range from 1 to 65 percent. The mean annual precipitation is l2 to l6 inches (305 to 406 mm). The mean annual air temperature is 57 to 68 degrees F (14 to 20 degrees C). The frost-free period is 170 to 240 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alsco, Maloy, Selevin, and White House soils. Alsco and Maloy soils are loamy-skeletal. Selevin soils have a clay fraction dominated by smectitic mineralogy. White House soils have less than 35 percent rock fragments.

DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; slow or very slow permeability.

USE AND VEGETATION: Eloma soils are used for livestock grazing and wildlife habitat. The present vegetation is sideoats grama, black grama, threeawn, plains lovegrass, curly mesquite, Rothrock grama, mesquite, catclaw, sotol, agave and yucca.

DISTRIBUTION AND EXTENT: Southern, Central and Northwestern Arizona. This series is of moderate extent. MLRA is 38 and 41.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: Graham County, Arizona; Soil survey of Gila-Duncan Area, Arizona, Parts of Graham and Greenlee Counties; 1979.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - the zone from 0 to 2 inches (0 to 5 cm) (A horizon)

Argillic horizon - the zone from 2 to 45 inches (5 to 114 cm) (Bt1, Bt2, Bt3, Bt4, Bt5 horizons)

Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Eleventh Edition, 2010

Revised for the correlation of AZ675, 5/2009, WWJ

Revised for the correlation of Graham County, AZ, Southwestern Part, March 2011, WWJ

Revised for the correlation the SDJR - MLRA 38 - Eloma very gravelly sandy clay loam, 3 to 65 percent slopes project, June 2013, LJG2

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National Cooperative Soil Survey
U.S.A.