LOCATION QUARTERMASTER AZEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Calciustepts
TYPICAL PEDON: Quartermaster extremely gravelly sandy loam - woodland. (Colors are for dry soil unless otherwise noted).
A--0 to 2 inches; yellowish brown (10YR 5/4) extremely gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; weak thick platy structure parting to moderate fine granular; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine irregular pores; 85 percent gravel; violently effervescent, 15 percent calcium carbonate equivalent; moderately alkaline (pH 8.0); abrupt smooth boundary. (2 to 3 inches thick)
Bw--2 to 8 inches; yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine roots; common very fine tubular and irregular pores; 12 percent gravel; violently effervescent, 16 percent calcium carbonate equivalent; slightly alkaline (pH 7.8); clear smooth boundary. (6 to 12 inches thick)
Bk1--8 to 19 inches; yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 4/4) moist; moderate coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine, few fine and few medium roots; common very fine and few fine tubular pores; 10 percent gravel; few distinct calcium carbonate masses on peds and as coatings on gravel; violently effervescent, 18 percent calcium carbonate equivalent; slightly alkaline (pH 7.8); abrupt wavy boundary. (7 to 12 inches thick)
Bk2--19 to 26 inches; yellowish brown (10YR 5/4) cobbly loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine, medium and coarse roots; few very fine tubular pores; 15 percent cobble and 10 percent gravel, consisting of limestone and hardpan fragments; many prominent calcium carbonate pendants on undersides of rock fragments; violently effervescent, 21 percent calcium carbonate equivalent; moderately alkaline (pH 8.0); abrupt wavy boundary. (6 to 10 inches thick)
2Bkm--26 to 60 inches; laminar capped petrocalcic horizon; violently effervescent.
TYPE LOCATION: Mohave County, Arizona; on the Hualapai Indian Reservation; approximately 2200 feet west and 2600 feet south of the northeast corner of section 31, T. 28 N., R. 14 W.
RANGE IN CHARACTERISTICS:
Soil moisture: Intermittently moist in some part of the soil moisture control section during December - March and July - September. Driest during May and June. Aridic ustic soil moisture regime.
Soil Temperature: 54 to 56 degrees F.
Depth to calcic horizon: 2 to 20 inches
Depth to petrocalcic horizon: 20 to 40 inches
Clay content: averages 18 to 27 percent in the control section
Content of gravel on the surface: 40 to 85 percent.
Rock fragments: 5 to 30 percent in the control section
Reaction: slightly to moderately alkaline
A horizon
Hue: 7.5YR, 10YR
Value: 5 or 6 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Bw horizon
Hue: 7.5YR, 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Texture: sandy loam, loam, sandy clay loam
Rock fragments: 5 to 15 percent gravel
Bk horizons
Hue: 7.5YR, 10YR
Value: 4 through 6 dry, 3 through 5 moist
Chroma: 3 or 4, dry or moist
Texture: sandy loam, loam, sandy clay loam
Calcium carbonate equivalent: 15 to 40 percent. Weak to strong cementation in the lower part.
Rock fragments: contains 5 to 20 percent in the upper part, and from 25 to 55 percent rock and hardpan fragments in the lower part
The Bw horizon is not present in some pedons.
COMPETING SERIES: These are the Cibeque (AZ), Coconino (AZ), and Kandrix (CO) series. Cibeque, Coconino, and Kandrix soils do not have a petrocalcic horizon. In addition, Cibeque and Kandrix soils are very deep and Coconino soils have bedrock at 20 to 40 inches.
GEOGRAPHIC SETTING: Quartermaster soils are on footslopes of fan terraces. These soils formed in alluvium derived dominantly from limestone and basalt. Elevations are 4600 to 5500 feet. Slopes range from 2 to 12 percent. The mean annual air temperature is 52 to 54 degrees F. The mean annual precipitation is 14 to 18 inches. The frost-free period is 120 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buckndoe, Luzena, Lykorly, Milkweed, and Wodomont soils. Buckndoe soils are deep to a hardpan. Luzena and Wodomont soils have a lithic contact above 20 inches. Lykorly soils are very deep. Milkweed soils are shallow to a petrocalcic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Quartermaster soils are used for grazeable woodland and wildlife habitat. The present vegetation is Utah juniper, blue grama, bottlebrush squirreltail, and Indian ricegrass.
DISTRIBUTION AND EXTENT: Northwestern Arizona. This series is of minor extent.
MLRA 39 and 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Mohave County, Arizona; Soil survey of the Hualapai-Havasupai Area, Parts of Coconino, Mohave, and Yavapai Counties; 1993.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 2 inches (A horizon)
Calcic horizon - The zone from 8 to 26 inches (Bk1, Bk2 horizons)
Petrocalcic horizon - The zone from 26 to 60 inches (2Bkm horizon)
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003.
A proposal has been submitted to recognize a Petrocalcic Ustochrepts subgroup.