LOCATION DELENBAW AZEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Aridic Argiustolls
TYPICAL PEDON: Delenbaw very cobbly loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; dark reddish gray (5YR 4/2) very cobbly loam, dark reddish brown (5YR 3/2) moist; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; few fine and very fine roots; common fine and very fine tubular and irregular pores; 20 percent gravel, 30 percent cobble and 5 percent stones; noneffervescent; slightly alkaline (pH 7.4); abrupt smooth boundary. (1 to 2 inches thick)
Bt1--2 to 10 inches; dark reddish gray (5YR 4/2) very cobbly clay loam, dark reddish brown (5YR 3/2) moist; moderate medium subangular blocky structure; very hard, very firm, sticky and plastic; common fine and very fine roots; common fine and very fine tubular and interstitial pores; few faint clay films on faces of peds and lining pores; 5 percent gravel and 40 percent cobble; noneffervescent; slightly alkaline (pH 7.4); clear smooth boundary. (6 to 10 inches thick)
Bt2--10 to 30 inches; reddish brown (5YR 4/3) very cobbly clay, dark reddish brown (5YR 3/3) moist; strong medium angular blocky structure; very hard, very firm, very sticky and very plastic; common fine and very fine roots; few fine and very fine tubular and interstitial pores; many pressure faces; common faint clay films on faces of peds and lining pores; few distinct organic coats on faces of peds; 5 percent gravel and 40 percent cobble; noneffervescent; slightly alkaline (pH 7.6); clear smooth boundary. (15 to 25 inches thick)
Bt3--30 to 36 inches; reddish brown (5YR 5/4) gravelly clay, reddish brown (5YR 4/4) moist, strong fine angular blocky structure; very hard, very firm, very sticky and very plastic; common fine and very fine roots; common fine and very fine tubular and interstitial pores; many pressure faces; common faint clay films on faces of peds and lining pores; 20 percent gravel; noneffervescent; slightly alkaline (pH 7.6); clear smooth boundary. (0 to 10 inches thick)
2Bt4--36 to 52 inches; reddish yellow (5YR 6/6) and reddish brown (5YR 5/4) very cobbly clay loam, yellowish red (5YR 5/6) and reddish brown (5YR 4/4) moist; strong fine angular blocky structure; very hard, very firm, sticky and plastic; common fine and very fine roots; few fine tubular and interstitial pores; few faint clay films on faces of peds and rock fragments; 20 percent cinders and 20 percent cobble; noneffervescent; moderately alkaline (pH 8.0); clear smooth boundary. (10 to 20 inches thick)
2Bt5--52 to 60 inches; yellowish red (5YR 5/6) very cobbly clay loam, yellowish red (5YR 4/6) moist; strong fine angular blocky structure; very hard, very firm, sticky and plastic; few fine roots; few fine and very fine tubular and interstitial pores; few faint clay films on faces of peds and rock fragments; 20 percent cobble and 20 percent cinders; noneffervescent; moderately alkaline (pH 8.0).
TYPE LOCATION: Mohave County, Arizona; about 11.7 miles south of the Arizona-Utah state line and 17 miles east of the Arizona-Nevada state line on Black Rock Mountain; 1400 feet south and 500 feet east of the northwest corner of section 31, T.40 N., R.13 W.; 36 degrees, 49 minutes, 31 seconds North Latitude and 113 degrees, 44 minutes, 29 seconds West Longitude.
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.
Dark colors below the mollic epipedon are lithochromic
Soil Temperature: 50 to 54 degrees F.
Organic Matter: 1 to 2 percent in the upper horizons
A horizon
Hue: 5YR, 2.5YR
Value: 3 through 5 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist
Reaction: neutral to slightly alkaline
Rock fragments: 0 to 10 percent stones
20 to 30 percent cobble
10 to 20 percent gravel
Bt horizon
Hue: 5YR, 2.5YR
Value: 3 through 5 dry, 3 or 4 moist
Chroma: 2 through 6, dry or moist
Texture: clay loam, clay (35 to 60 percent clay)
Rock fragments: 0 to 10 percent stones
20 to 40 percent cobble
5 to 20 percent gravel
2Bt horizon
Hue: 5YR, 2.5YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 through 6, dry or moist
Texture: clay loam, clay (35 to 45 percent clay)
Rock fragments: 15 to 40 percent cobble
15 to 40 percent cinders
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Delenbaw soils are on mesas and mesa escarpments and have slopes of 3 to 25 percent. These soils formed in colluvium and alluvium derived dominantly from basalt but include influences from other volcanic rocks. Elevations range from 5800 to 6500 feet. The mean annual air temperature is 48 to 52 degrees F. Mean annual precipitation is 14 to 18 inches. The frost-free period is 135 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Luzena, Pocum, Springerville and Yellowhorse series. Luzena soils have a lithic contact within 20 inches of the surface. Pocum soils have a petrocalcic horizon within 20 inches of the surface. Springerville and Yellowhorse soils average less than 35 percent rock fragments in the control section.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; very slow permeability.
USE AND VEGETATION: Delenbaw soils are used for livestock grazing and wildlife habitat. The present vegetation is juniper, pinyon pine, Utah serviceberry, big sagebrush, cliffrose, junegrass, and crested, intermediate, and western wheatgrasses.
DISTRIBUTION AND EXTENT: Northwestern Arizona. This series is of small extent. MLRA is 39.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Mohave County, Arizona; Soil survey of Shivwits Area, Arizona, Part of Mohave County; 1994.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from 0 to 10 inches (A, Bt1 horizons)
Argillic horizon - The zone from 2 to 60 inches (Bt1, Bt2, Bt3, 2Bt4, 2Bt5 horizons)