LOCATION PRIETA NM+AZEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, mixed, superactive, mesic Lithic Ustic Haplargids
TYPICAL PEDON: Prieta very stony loam--rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; brown (10YR 5/3) very stony loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and very fine roots; 40 percent stones; neutral; clear smooth boundary. (1 to 4 inches thick)
Bt1--3 to 10 inches; yellowish brown (10YR 5/4) very stony clay loam, brown (7.5YR 4/4) moist; moderate fine subangular blocky structure; hard, firm, very sticky and very plastic; common fine and very fine roots; thin continuous clay films on faces of peds; 40 percent stones and 10 percent gravel; slightly alkaline; gradual smooth boundary. (2 to 8 inches thick)
Bt2--10 to 14 inches; brown (7.5YR 5/4) very stony clay loam, brown (7.5YR 4/4) moist; weak medium subangular blocky structure; hard, firm, sticky and plastic; common fine and very fine roots; thin continuous clay films on faces of peds; 25 percent stones and 10 percent gravel; moderately alkaline; clear smooth boundary. (2 to 5 inches thick)
Bk--14 to 19 inches; very pale brown (10YR 7/3) very stony clay loam, brown (10YR 5/3) moist; massive; slightly hard, friable, sticky and plastic; few fine roots; 40 percent stones and 10 percent gravel; common fine filaments of calcium carbonate; moderately alkaline; abrupt smooth boundary. (1 to 6 inches thick)
2R--19 inches; basalt.
TYPE LOCATION: Sandoval County, New Mexico; on Prieta Mesa, 580 feet east and 2600 north of the southwest corner of sec. 15, T. 14 N., R. 2 W.
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is dry in all parts during May and June and is moist in some part periodically from July 1 to the end of October. The soil moisture control section is dry in all parts 50 to 75 percent of the time that the soil temperature is above 41 degrees F. Ustic aridic moisture regime.
Soil temperature: 51 to 61 degrees F.
Depth to basalt: 6 to 20 inches
A horizon
Hue: 10YR or 7.5YR
Value: 4 through 6 dry, 3 or 4 moist
Chroma: 2 through 4
Texture: very gravelly loam, very stony loam, stony silt loam or stony silty clay loam.
Bt horizons
Hue: 10YR or 7.5YR
Value: 4 or 6 dry, 3 or 5 moist
Chroma: 2 through 4
Soil colors: soil colors are lithochromic. When colors meet the requirements for mollic, the organic matter is too low
Texture: silty clay, clay, clay loam or silty clay loam
Clay content: 35 to 50 percent
Rock fragments: 35 to 70 percent.
Bk horizon
Hue: 10YR or 7.5YR
Value: 4 through 7 dry, 3 or 6 moist
Chroma: 2 through 4
Texture: clay loam or silty clay loam
Clay content: 35 to 40 percent
Rock fragments: 35 to 60 percent
COMPETING SERIES: There are no competing series in the same family.
GEOGRAPHIC SETTING: The Prieta soils formed in eolian material and alluvium weathered from basalt. Slopes range from 1 to 35 percent. Elevations range from 4,200 to 8,000 feet. Mean annual precipitation ranges from 10 to 14 inches. The mean annual air temperature is about 49 to 59 degrees F. The frost-free period ranges from 120 to 165 days. In Arizona the frost-free period is as long as 175 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the Curhollow soils. Curhollow soils average less than 18 percent clay and are shallow to a petrocalcic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; slow permeability.
USE AND VEGETATION: Used mainly for livestock grazing and recreation. Native vegetation is mainly blue grama, black grama, western wheatgrass, camiza, galleta, little bluestem, Texas timothy and winterfat.
DISTRIBUTION AND EXTENT: This series is extensive in northern and western New Mexico and northern Arizona. MLRAs 36 and 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Upper Puerco Reconnaissance Soil Survey, 1937.
REMARKS: Diagnostic horizons and features recognized in this pedon are.
Ochric epipedon: The zone from the surface to a depth of 3 inches. (A horizon)
Argillic horizon: The zone from about 3 to 14 inches. (Bt1, Bt2 horizons)
Secondary carbonates: The zone from about 14 to 19 inches. (Bk horizon)
Lithic contact: The boundary of about 19 inches. (2R horizon)
The type Location of the Prieta series was moved to Sandoval County in 1976 to better reflect the concepts of the Prieta series. The classification was not changed.
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003.