LOCATION HAVASUPAI AZEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic, shallow Calcic Petrocalcids
TYPICAL PEDON: Havasupai very gravelly loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; brown (7.5YR 5/2) very gravelly loam, dark brown (7.5YR 3/2) moist; weak fine subangular blocky structure parting to weak fine granular; soft, very friable, nonsticky and slightly plastic; many very fine roots; many very fine irregular pores; 55 percent fine gravel as surface lag layer; strongly effervescent, 16 percent calcium carbonate equivalent; slightly alkaline (pH 7.5); abrupt smooth boundary. (1 to 3 inches thick)
Bk1--2 to 7 inches; yellowish brown (10YR 5/4) gravelly loam, dark yellowish brown (10YR 3/4) moist; weak fine subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; many very fine roots; common very fine tubular pores; 20 percent gravel and 5 percent cobble; few thin calcium carbonate coatings under rock fragments; strongly effervescent, 14 percent calcium carbonate equivalent; slightly alkaline (pH 7.4); clear wavy boundary. (3 to 8 inches thick)
Bk2--7 to 14 inches; light brown (7.5YR 6/4) very gravelly sandy clay loam, brown (7.5YR 5/4) moist; weak fine subangular blocky structure; hard, friable, nonsticky and slightly plastic; common very fine roots; few very fine tubular pores; 30 percent gravel and 10 percent cobble; common thin calcium carbonate coatings on rock fragments; violently effervescent, 45 percent calcium carbonate equivalent; slightly alkaline (pH 7.5); abrupt wavy boundary. (5 to 9 inches thick)
Bkm--14 to 33 inches; laminar capped, calcium carbonate cemented hardpan; abrupt wavy boundary. (6 to 24 inches thick)
2Bk--33 to 60 inches; reddish brown (5YR 5/4) extremely gravelly sand, reddish brown (5YR 4/4) moist; massive; very hard, friable, nonsticky and nonplastic; 80 percent gravel and 5 percent cobble; many thick calcium carbonate coatings and pendants on rock fragments; weak to strong discontinuous calcium carbonate cementation; violently effervescent; slightly alkaline (pH 7.4).
TYPE LOCATION: Coconino County, Arizona; Hualapai Indian Reservation, 2400 feet west and 1400 feet south of the northeast corner of Section 4, T. 25 N., R. 9 W.
RANGE IN CHARACTERISTICS:
Soil moisture: Intermittently moist in some part of the soil moisture control section during July - September and December - March. Driest during May and June. Ustic aridic soil moisture regime.
Soil Temperature - 54 to 58 degrees F.
Rock fragments - averages 35 to 70 percent in the control section
Depth to petrocalcic horizon - 10 to 20 inches
Clay content - averages more than 18 percent in the control section
Calcium carbonate - averages 15 to 35 percent in the control section
Reaction: slightly or moderately alkaline
A horizon
Hue: 7.5YR, 10YR
Value: 5 or 6 dry, 3 through 5 moist
Chroma: 2 through 4, dry or moist
Bk horizons
Hue: 7.5YR, 10YR
Value: 4 through 8 dry, 3 through 5 moist
Chroma: 3 through 5, dry or moist
Texture: fine sandy loam, sandy clay loam, sandy loam, loam
2Bk or C horizons
Hue: 5YR, 7.5YR
Value: 5 through N8/ dry, 4 through 8 moist
Chroma: 0 through N8/, dry or moist
Texture: sand, coarse sand, sandy loam, coarse sandy loam, loamy coarse sand
Rock fragments: 35 to 90 percent gravel and cobble
COMPETING SERIES: These are the Childers (AZ), Curhollow (UT), Pibler (UT), and Pinetown (UT) series. Childers and Curhollow soils have bedrock below the petrocalcic horizon. Pibler soils are usually moist in winter and spring, dry in summer and fall, and have an aridic soil moisture regime that borders on xeric. Pinetown soils have mean annual soil temperature of 47 to 51 degrees F.
GEOGRAPHIC SETTING: Havasupai soils are on fan terraces at elevations of 4300 to 6000 feet. Slopes range from 1 to 35 percent. These soils formed in tertiary alluvium derived dominantly from sedimentary and igneous rocks. The mean annual precipitation is 10 to 14 inches. The mean annual air temperature is 52 to 56 degrees F. Frost-free period is 135 to 175 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Barx, Cibeque, Curhollow, and Winona soils. Barx and Cibeque soils are fine-loamy and very deep. Winona soils are shallow to limestone.
DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; moderate permeability.
USE AND VEGETATION: Havasupai soils are used for livestock grazing and wildlife habitat. Vegetation is black grama, blue grama, needleandthread, banana yucca and Fremont barberry.
DISTRIBUTION AND EXTENT: Northern Arizona. This soil is moderately extensive. MLRA is 35
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Mohave County, Arizona; Soil survey of Mohave County Area, Arizona, Northeastern Part, and Part of Coconino County; 1992.
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 7 to 14 inches (Bk2 horizon)
Petrocalcic horizon - The zone from 14 to 33 inches (Bkm horizon)
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003.