LOCATION PINAMT AZEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, hyperthermic Typic Calciargids
TYPICAL PEDON: Pinamt extremely gravelly sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 1 inch; brown (7.5YR 5/4) extremely gravelly sandy loam, brown (7.5YR 4/4) moist; moderate thin platy structure; soft, friable, nonsticky and nonplastic; many very fine roots; common fine irregular pores; 65 percent gravel and 5 percent cobble; slightly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (1 to 3 inches thick)
A2--1 to 3 inches; light brown (7.5YR 6/4) very gravelly loam, strong brown (7.5YR 4/6) moist; weak very fine subangular blocky structure; soft, friable, nonsticky and slightly plastic; common very fine roots; common very fine irregular pores; 40 percent gravel; slightly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (1 to 10 inches thick)
Btk1--3 to 15 inches; yellowish red (5YR 5/6) very gravelly sandy clay loam, yellowish red (5YR 4/6) moist; weak fine subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; common fine and medium roots; common very fine tubular and few fine irregular pores; few faint clay films on faces of peds and lining pores; 40 percent gravel and 5 percent cobble; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (8 to 20 inches thick)
Btk2--15 to 28 inches; light brown (7.5YR 6/4) extremely gravelly sandy clay loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; common very fine tubular pores; 50 percent gravel and 10 percent cobble; strongly effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (5 to 15 inches thick)
C--28 to 60 inches; light brown (7.5YR 6/4) extremely gravelly sandy loam, brown (7.5YR 4/4) moist; massive; slightly hard, friable, nonsticky and slightly plastic; few very fine roots; 60 percent gravel and 5 percent cobble; strongly effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Maricopa County, Arizona; 150 feet north and 1,250 feet west of the southeast corner of section 5, T. 5 N., R. 1 E. Latitude 33 degrees, 47 minutes, 54 seconds N., Longitude 112 degrees, 16 minutes, 37 seconds W., NAD 83.
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some part of the soil moisture control section during July-September and December-February. The soil is driest during May and June. Typic aridic soil moisture regime.
Soil temperature - 72 to 78 degrees F.
Rock Fragments: 35 to 90 percent
Salinity: Nonsaline to strongly saline
Sodicity: Nonsodic to strongly sodic
Reaction: Slightly to strongly alkaline
Clay content: Averages more than 18 percent clay in the control section
Depth to calcic horizon: 5 to 40 inches. Calcium carbonate equivalent ranges to 25 percent
Depth to base of argillic horizon: 25 to 40 inches
A horizon
Hue: 7.5YR, 10YR
Value: 4 through 7 dry, 3 through 6 moist
Chroma: 3, 4 or 6, dry or moist
Calcium carbonate: Noneffervescent to strongly effervescent
B horizon
Hue: 2.5YR, 5YR, 7.5YR
Value: 4 through 6 dry, 3 through 5 moist
Chroma: 4 or 6, dry or moist
Texture: Loam, sandy clay loam, sandy loam, clay loam
Calcium carbonate: Noneffervescent to violently effervescent
C horizon
Hue: 7.5YR, 10YR
Value: 5, 6, 7 or 8 dry, 4 through 7 moist
Chroma: 2 through 6, dry or moist
Texture: Sandy loam, loam, sandy clay loam, but can range to include coarser textures
Calcium carbonate: Slightly to violently effervescent
COMPETING SERIES: These are the Chuckawalla (CA), Cololag (NV) and Cristobal (AZ) series. Chuckawalla soils are less than 25 inches to the base of the argillic horizon. Cololag soils have less than 18 percent clay in the control section. Cristobal soils are more than 40 inches to the base of the argillic horizon.
GEOGRAPHIC SETTING: Pinamt soils are on fan terraces and stream terraces and have slopes of 0 to 40 percent. These soils formed in fan alluvium and stream alluvium from mixed sources. Elevations range from 700 to 3,000 feet. The mean annual precipitation ranges from 2 to 10 inches. The mean annual air temperature is 69 to 75 degrees F. The frost-free period is 240 to 325 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Antho, Ebon, Gunsight, Mohall, Momoli, Rillito and Tremant soils. Antho soils are coarse-loamy and Ebon soils are clayey-skeletal. Mohall and Tremant soils are fine-loamy. Gunsight, Momoli and Rillito soils do not have argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.
USE AND VEGETATION: Pinamt soils are used for livestock grazing and wildlife habitat. The present vegetation is creosotebush, bursage, cactus, paloverde, ironwood, and annual grasses and forbs.
DISTRIBUTION AND EXTENT: South-central and southwestern Arizona. This series is extensive. Total extent is about 140,000 acres. MLRA is 40.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Maricopa County (Eastern Maricopa- Northern Pinal Counties Area), Arizona; 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 3 inches (A1, A2 horizons)
Argillic horizon - the zone from 3 to 28 inches (Btk1, Btk2 horizons)
Calcic horizon - the zone from 3 to 60 inches (Btk1, Btk2, C horizons)
Segregated calcium carbonate is assumed at depths of 3 to 60 inches although not described, PDC.
Pinamt and its competitors were originally differentiated on degrees of salinity. This distinction could not be consistently recognized. The type location was moved in 1988 to accommodate revised series separations based on depth to the base of the argillic horizon, PDC.
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006.
Revised for the correlation of AZ661, 2/2009, WWJ