LOCATION SUPERSTITION AZ+CAEstablished Series
TAXONOMIC CLASS: Sandy, mixed, hyperthermic Typic Haplocalcids
TYPICAL PEDON: Superstition sand - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 5 inches; light brown (7.5YR 6/4) sand, brown (7.5YR 5/4) moist; weak thin platy structure; soft, very friable, common fine and very fine roots; many fine irregular and few fine tubular pores; 3 percent gravel; slightly effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (3 to 10 inches thick)
Bk1--5 to 23 inches; light brown (7.5YR 6/4) sand, brown (7.5YR 5/4) moist; massive; soft, very friable; common fine and very fine roots; many fine irregular and few fine tubular pores; 3 percent gravel; few fine soft calcium carbonate accumulations; strongly effervescent; moderately alkaline (pH 8.2); clear wavy boundary. (11 to 20 inches thick)
Bk2--23 to 42 inches; light brown (7.5YR 6/4) sand, brown (7.5YR 5/4) moist; massive; soft, friable; few fine roots; many fine irregular pores; 2 percent nodules; common fine soft calcium carbonate accumulations; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (10 to 30 inches thick)
Bk3--42 to 60 inches; pink (7.5YR 7/4) sand, brown (7.5YR 5/4) moist; massive; soft, very friable; many fine irregular pores; few fine soft calcium carbonate accumulations; strongly effervescent; moderately alkaline (pH 8.4).
TYPE LOCATION: Yuma County, Arizona; about 3.5 miles east of San Luis; 1,990 feet south and 1,990 feet west of the northeast corner of Section 9, T. 9 S., R. 24 W.
RANGE IN CHARACTERISTICS:
Soil Moisture: Usually dry but may be 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.
Soil Temperature: 72 to 78 degrees F.
Depth to calcic horizon: 5 to 30 inches
Calcium carbonate equivalent: 5 to 15 percent that decreases with depth
A horizon
Hue: 7.5YR, 10YR
Value: 6, 7 or 8 dry, 4, 5 or 6 moist
Chroma: 2, 3 or 4, dry or moist
B horizon
Hue: 7.5YR, 10YR
Value: 6, 7 or 8 dry, 3 through 7 moist
Chroma: 2 through 6, dry or moist
Texture: Loamy sand, loamy fine sand, fine sand, sand
COMPETING SERIES: This is the Buzzardsprings (T) (CA) series. Buzzardsprings soils contain durinodes and exhibit weak to moderate cementation by silica and calcium carbonate in the lower portion of the profile. In addition, Buzzardsprings soils receive mostly winter precipitation and are usually dry April through November.
GEOGRAPHIC SETTING: Superstition soils are on dunes at elevations of 40 to 2,500 feet. These soils formed in sandy eolian deposits. Slopes range from 0 to 10 percent. The mean annual precipitation is 2 to 7 inches. The mean annual air temperature is 70 to 76 degrees F. The frost-free period is 240 to 350 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Rositas, Dateland, Pinamt and Tremant soils. Pinamt and Tremant soils have argillic horizons. Dateland and Rositas soils do not have calcic horizons.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very low and low runoff; rapid permeability.
USE AND VEGETATION: Superstition soils are used for livestock grazing and irrigated cropland. The present vegetation is creosotebush and bursage.
DISTRIBUTION AND EXTENT: Southern and northwestern Arizona and extreme southern California. This series is of moderate extent. MLRAs 31 & 40.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: El Centro Area, California; 1918.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 5 inches (A horizon)
Calcic horizon - The zone from 23 to 42 inches (Bk2 horizon)
Classified according to Keys to Soil Taxonomy, Ninth Edition, 2003.