LOCATION PURGATORY AZEstablished Series
TAXONOMIC CLASS: Fine-loamy, gypsic, mesic Leptic Haplogypsids
TYPICAL PEDON: Purgatory gravelly fine sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; yellowish red (5YR 5/6) gravelly fine sandy loam, yellowish red (5YR 4/6) moist; weak thick platy structure; slightly hard, very friable, nonsticky and nonplastic; few fine, medium and coarse roots; many very fine vesicular pores; 30 percent fine gravel; strongly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (l to 4 inches thick)
By1--2 to 14 inches; variegated pink (5YR 8/3) and yellowish red (5YR 5/6) sandy loam, pink (5YR 7/3) and yellowish red (5YR 4/6) moist; massive; soft, very friable, nonsticky and nonplastic; few fine and very fine roots; common fine and very fine tubular pores; 10 percent soft shale fragments; common gypsum crystals; slightly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (8 to 14 inches thick)
2By2--14 to 26 inches; variegated light gray (N 7/) clay loam, gray (N 5/) moist; massive; hard, very friable, slightly sticky and slightly plastic; few fine roots; few very fine tubular pores; 20 percent soft gravel; common gypsum crystals; slightly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (6 to 14 inches thick)
2By3--26 to 34 inches; variegated light gray (N 7/) clay loam, gray (N 5/) moist; reddish brown (2.5YR 4/4) and dark red (2.5YR 3/6) moist, rubbed; massive; hard, very friable, slightly sticky and slightly plastic; few very fine tubular pores; 10 percent soft gravel; common gypsum crystals; slightly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (5 to 8 inches thick)
3Cr--34 inches; variegated thin bedded shale.
TYPE LOCATION: Coconino County, Arizona; approximately 5 miles west of Winslow; about 2 miles north of I-40 on Leupp Road, 200 feet west of Leupp Road; 250 feet south and 2,000 feet west of the northeast corner of section 33, T. 20 N., R. 14 E.
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. Typic aridic soil moisture regime.
Depth to paralithic contact - 20 to 40 inches
Rock fragments - 5 to 30 percent
Depth to gypsic horizon - 1 to 8 inches
A horizon
Hue: 5YR, 7.5YR, 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3, 4, 5 or 6, dry or moist
Texture: Very fine sandy loam, fine sandy loam, sandy loam, loam (10 to 15 percent clay)
Reaction: slightly alkaline or moderately alkaline
B horizon
Hue: 5YR, 7.5YR
Value: 5, 6, 7 or 8 dry, 3, 4, 5, 6 or 7 moist
Chroma: 0, 3, 4 or 6, dry or moist
Texture: Sandy loam, fine sandy loam, clay loam, loam (averages 18 to 35 percent clay)
Reaction: Slightly alkaline or moderately alkaline
Calcium carbonate: Less than 15 percent; segregated as masses or disseminated
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Purgatory soils are at elevations of 4,800 to 7,000 feet on plateaus and mesas. Slopes range from 0 to 8 percent. They formed in eolian deposits over alluvium from gypsiferous shale. The climate is semiarid with a mean annual precipitation of 6 to 10 inches. The mean annual air temperature ranges from 49 to 55 degrees F. The frost-free period is 120 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ives, Epikom, Navajo and Tours soils. These soils do not have gypsic horizons. Epikom soils are shallow. Ives, Tours and Navajo soils are very deep.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate or moderately slow permeability.
USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation is gyp dropseed, galleta, Indian ricegrass, alkali sacaton, shadscale, fourwing saltbush, Bigelow sagebrush, black grama, Mormon-tea and yucca.
DISTRIBUTION AND EXTENT: Northern Arizona and southern Utah. Purgatory soils are of large extent. MLRA 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Virgin River Area, Utah-Arizona; 1936.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 2 inches (A horizon)
Gypsic horizon - The zone from 2 to 34 inches (By1, 2By2, 2By3 horizons)
Paralithic contact - The boundary at 34 inches (3Cr horizon)
Additional Data: NSSL data numbers S75AZ 005 005 and S77AZ 017 005