LOCATION ESKIMINZIN              AZ

Established Series
Rev. CRP/JFW/RFG
10/2014

ESKIMINZIN SERIES

The Eskiminzin series consists of very shallow and shallow, well drained soils formed in slope alluvium and residuum from basic igneous rock. Eskiminzin soils are on hills and mountains and have slopes of 0 to 65 percent. Mean annual precipitation is about 14 inches (356 mm) and the mean annual air temperature is about 61 degrees F (16.1 degrees C).

TAXONOMIC CLASS: Clayey-skeletal, smectitic, thermic Lithic Ustic Haplargids

TYPICAL PEDON: Eskiminzin extremely cobbly loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches (0 to 8 cm); dark brown (7.5YR 3/3) extremely cobbly loam, dark brown (7.5YR 3/2) moist; strong fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine pores; 35 percent gravel, 30 percent cobble, 3 percent stone; noneffervescent; slightly alkaline (pH 7.8); clear wavy boundary. (1 to 4 inches or 3 to 10 cm thick)

Bt--3 to 9 inches (8 to 23 cm); brown (7.5YR 4/3) very gravelly clay, dark brown (7.5YR 3/3) moist; strong medium and coarse angular blocky structure; hard, firm, very sticky and very plastic; many very fine and fine roots; many very fine and fine pores; many prominent pressure faces; many continuous, distinct clay films on ped faces and rock fragments; 39 percent gravel, 10 percent cobble; noneffervescent; neutral (pH 7.2); clear wavy boundary. (5 to 16 inches or 13 to 41 cm thick)

Cr--9 to 11 inches (23 to 28 cm); slightly weathered basalt; clear wavy boundary. (0 to 4 inches or 0 to 10 cm thick)

R--11 inches (28 cm); basalt bedrock.

TYPE LOCATION: Pinal County, Arizona on the San Carlos Indian Reservation; 32 58' 08.00" North Latitude, 110 37' 52.54" West Longitude, NAD83; Topographic quadrangle: Dudleyville, Arizona. About 2,600 feet north and 2,225 feet east of the southwest corner of sec. 29, T. 5 S., R. 17 E. Approximately 7 miles east of Hwy 77 near Winkleman, Arizona, just off Road 300.

RANGE IN CHARACTERISTICS:
Soil moisture - Intermittently moist in some part of the soil moisture control section during July-September and December-March. Driest during May and June. Ustic Aridic soil moisture regime.

Soil temperature - 59 to 69 degrees F (15 to 20.6 degrees C).

Particle-size control section (weighted average):
Clay Content: 35 to 60 percent
Rock Fragments: 35 to 75 percent

Surface fragments: 0 to 85 percent gravel, cobble, and stones

Depth to bedrock: 6 to 20 inches (15 to 51 cm)
Effervescence: none to slight
Reaction (pH): slightly acid to slightly alkaline (6.1 to 7.8)

A horizon
Hue: 2.5YR, 7.5YR, 10YR
Value: 3 to 5 dry, 2 to 4 moist
Chroma: 2 to 4, dry or moist
Texture: loam, silty clay loam, clay loam, clay
Rock fragments: 35 to 70 percent

Bt horizon
Hue: 2.5YR, 5YR, 7.5YR
Value: 3 to 5 dry, 2 to 4 moist
Chroma: 2 to 4, dry or moist
Texture: clay, silty clay, clay loam
Rock fragments: 35 to 75 percent
Calcium carbonate equivalent: 0 to 5 percent

Cr horizon (where present)
Weathered basalt or andesite bedrock that is less than 4 inches thick

R horizon
Hard basalt or andesite bedrock

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Eskiminzin soils are on hills and mountains. Slopes are dominantly 15 to 45 percent and range from 0 to 65 percent. The Eskiminzin soils formed in slope alluvium and residuum from basalt, andesite, rhyolite, tuff and other extrusive igneous rocks and elevation ranges from 2,500 feet to 5,500 feet (762 to 1676.4 meters). The mean annual air temperature is 57 to 67 degrees F (13.9 to 19.4 degrees C). Mean annual precipitation ranges from 12 to 16 inches (305 to 406 mm) and occurs mainly as thundershowers in July and August and rains in December and January. The frost-free period is 180 to 240 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Sontag, Pantak and Graham soils. Graham and Sontag soils have less than 35 percent rock fragments and Sontag soils are also deeper than 20 inches. Pantak soils have less than 35 percent clay in the particle-size control section.

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

USE AND VEGETATION: Used for livestock grazing and wildlife habitat. The vegetation is sideoats grama, curly mesquite, tobosa grass, threeawn, ocotillo, prickly pear, annual grasses, Catclaw acacia, and occasional juniper and mesquite.

DISTRIBUTION AND EXTENT: Central Arizona. Eskiminzin soils are of limited extent. MLRAs are 38 and 41.

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

SERIES ESTABLISHED: Pinal County, Arizona; Soil Survey of Eastern Pinal and Southern Gila Counties, Arizona (AZ661), 2009.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 3 inches (0 to 8 cm) (A horizon)
Argillic horizon - the zone from 3 to 9 inches (8 to 23 cm) (Bt horizon)
Lithic contact - the boundary at 11 inches (28 cm) (R horizon)

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

Revised for the correlation of AZ661, 12/2008, WWJ
Revised for the correlation of AZ675, 5/2009, WWJ
Revised for the correlation of Graham County, AZ, Southwestern Part; March, 2011, WWJ
Update and revisions for the correlation of SDJR - MLRA 38 - Eskiminzin-Sontag-Rock outcrop complex, 2 to 45 percent slopes, Sept 2014, LJG2

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National Cooperative Soil Survey
U.S.A.