LOCATION DENAB AZEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Aridic Calciustolls
TYPICAL PEDON: Denab gravelly sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.) 60 to 80 percent of the surface is covered with fine gravel.
A--0 to 1 inch; brown (7.5YR 5/2) gravelly sandy loam, dark brown (7.5YR 3/2) moist; weak thin platy structure parting to weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine roots; common very fine irregular and interstitial pores; 20 percent gravel; many calcium carbonate coatings on rock fragments; strongly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (1 to 3 inches thick)
Bk--1 to 7 inches; brown (7.5YR 5/2) loam, brown (7.5YR 4/2) moist; moderate fine and medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; 5 percent gravel; many calcium carbonate coatings on rock fragments and common soft fine and medium calcium carbonate masses; violently effervescent, 15.5 percent calcium carbonate equivalent; moderately alkaline (pH 8.0); abrupt wavy boundary. (6 to 15 inches thick)
Crk--7 to 15 inches; interbedded tuff and calcareous loam; extremely hard; many distinct calcium carbonate coatings on rock fragments; common soft fine and medium calcium carbonate masses; common very fine and fine roots along fractures; clear wavy boundary. (5 to 10 inches thick)
R--15 inches; unweathered tuff.
TYPE LOCATION: Cochise County, Arizona; located about 2,100 feet west and 1,800 feet south of the northeast corner of section 15, Township 21 S., Range 28 E.; Pedregosa Mountain West topography map; latitude 31 degrees, 36 minutes, 15 seconds North and longitude 109 degrees, 29 minutes, 01 seconds West.
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. Aridic Ustic soil moisture regime.
Soil Temperature: 59 to 64 degrees F.
Rock fragments: 0 to 20 percent gravel
Reaction: slightly alkaline to moderately alkaline
Clay content: 3 to 18 percent in the control section
Organic matter: 1 to 3 percent
Depth to calcic horizon: 0 to 5 inches
Depth to weathered bedrock: 5 to 15 inches
Depth to unweathered bedrock: 10 to 20 inches
A horizon
Hue: 10YR, 7.5YR
Value: 3 through 5, dry or moist
Chroma: 2 through 4, dry or moist
Texture: sandy loam, loam
Bk horizon
Hue: 10YR, 7.5YR
Value: 3 through 5, dry or moist
Chroma: 2 through 4, dry or moist
Texture: sandy loam, loam
Calcium carbonate equivalent: 5 to 20 percent
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: The Denab soils are in the Chihuahuan desert on pediments at elevations of 4,600 to 6,200 feet. Slope ranges from 3 to 45 percent. These soils formed from slope alluvium and residuum derived from tuff. The mean annual precipitation is 16 to 20 inches and occurs as thunderstorms during July to September and as gentle rains during December and January. The mean annual air temperature is 57 to 62 degrees F. The frost-free period is 160 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Castledome, Cazador, Lesliecreek, Blacktail, Pyeatt, and Terrarossa soils. Castledome soil has greater than 35 percent clay over tuff. Cazador, Lesliecreek, Blacktail, Pyeatt, and Terrarossa soils are all very deep.
DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; moderately rapid permeability.
USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation includes sideoats grama, black grama, blue grama, threeawn, slim tridens, spikepappus grass and range ratany.
DISTRIBUTION AND EXTENT: Southeastern Arizona portion of the Chihuahuan desert. MLRA is 41. Denab soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Cochise County, Arizona; Soil Survey of Cochise County, Arizona, Douglas-Tombstone Part; 2000.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 0 to 7 inches (A and Bk horizons)
Calcic horizon - The zone from 1 to 7 inches (Bk horizon)
Paralithic contact - The boundary at 7 inches (Crk horizon)
Lithic contact - The boundary at 15 inches (R horizon)
Soil Taxonomy Second Edition, 1999