LOCATION THRONE AZ
Inactive Series
Rev. RKS/BAL/DWD/ET
12/2015
THRONE SERIES
The Throne series consists of moderately deep, well drained soils formed in colluvium and residuum derived from basalt. Throne soils are on basalt lava flows with slopes of 2 to 20 percent. The mean annual precipitation is about 10 inches. The mean annual air temperature is about 62 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Ustic Calciargids
TYPICAL PEDON: Throne extremely gravelly loam - rangeland and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with 55 percent basalt gravel, 15 percent cobble and 5 percent stone.
A1--0 to 2 inches; light yellowish brown (10YR 6/4) extremely gravelly loam; brown (10YR 4/3) moist; moderate thin platy structure; slightly hard, very friable, moderately sticky and moderately plastic; few very fine roots; many very fine and fine vesicular pores; 55 percent gravel, 5 percent cobble and 5 percent stone; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (1 to 2 inches thick)
A2--2 to 7 inches; pale brown (10YR 6/3) very gravelly loam; brown (10YR 4/3) moist; strong thin platy structure; slightly hard, very friable, moderately sticky and moderately plastic; few very fine roots; many very fine vesicular pores; 25 percent gravel, 15 percent cobble; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (0 to 6 inches thick)
Btk1--7 to 13 inches; brown (7.5YR 5/4) very cobbly silty clay loam; brown (7.5YR 4/3) moist; strong medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine through coarse roots; many very fine and fine, common medium and few coarse tubular pores; few faint clay films on faces of peds and lining pores; common fine soft masses and filaments of calcium carbonate; common thin calcium carbonate coats on undersides of rock fragments; 20 percent gravel, 25 percent cobble; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (3 to 13 inches thick)
Btk2--13 to 24 inches; brown (7.5YR 5/3) very cobbly silty clay loam; brown (7.5YR 4/3) moist; strong medium subangular blocky structure; slightly hard, very friable, very sticky and moderately plastic; common fine through coarse roots; many very fine and fine, common medium and few coarse tubular pores; few faint clay films on faces of peds and lining pores; common fine soft masses and filaments of calcium carbonate; common thin calcium carbonate coats on the undersides of rock fragments; 15 percent gravel, 25 percent cobble and 5 percent stone; violently effervescent; strongly alkaline (pH 8.6); clear smooth boundary. (10 to 16 inches thick)
Btkz--24 to 38 inches; brown (7.5YR 5/4) cobbly clay; brown (7.5YR 4/4) moist; strong fine subangular blocky structure; hard, very friable, very sticky and very plastic; few fine and medium roots; few fine and medium tubular pores; common distinct clay films on faces of peds and lining pores; many coarse soft masses of calcium carbonate; common thin calcium carbonate coats on the undersides of rock fragments; 5 percent gravel, 20 percent cobble and 5 percent stone; violently effervescent; very strongly alkaline (pH 9.2); abrupt irregular boundary. (0 to 6 inches thick)
R--38 inches; basalt bedrock.
TYPE LOCATION: Mohave County, Arizona; located about 1150 feet north and 1200 feet east of the southeast corner of Section 1, T. 32 N., R. 9 W.; 36 degrees 11 minutes 15 seconds north latitude and 113 degrees 12 minutes 15 seconds west longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Intermittently moist in some part of the soil moisture control section for 30 to 45 days cumulative, July through September. Driest during May and June. Ustic aridic soil moisture regime.
Soil temperature: 59 to 65 degrees F.
Rock Fragments: averages 35 to 50 percent in the particle-size control section
Depth to calcium carbonate: 1 to 8 inches
Depth to bedrock: 23 to 39 inches
A horizon
Hue: 7.5YR, 10YR
Value: 5 or 6 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist.
Btk horizons
Hue: 7.5YR,
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 or 4, dry or moist
Texture of the fine earth: silty clay loam, loam, clay loam
Clay content: 30 to 35 pecent
Calcium carbonate equivalent: 15 to 25 percent
Reaction: moderately alkaline to strongly alkaline
Btkz horizon (when present)
Texture of the fine earth: clay loam, clay
Clay content: 35 to 45 percent
Reaction: stronly alkaline to very strongly alkaline
COMPETING SERIES: This is the
Nolam (NM) series. Nolam soils are more than 60 inches deep.
GEOGRAPHIC SETTING: Throne soils are in concavities between pushups and ridges on basaltic lava flows. Slopes range from 2 to 20 percent. They formed in colluvium and residuum from basalt. Elevations range from 2500 to 4500 feet. The mean annual precipitation is 9 to 12 inches. The mean annual air temperature is 61 to 67 degrees F. The frost free period is 210 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Barten (T)(AZ) and
Hyrhy (T)(AZ) soils. These soils do not have a calcic horizon. In addition, Barten soils are less than 20 inches deep to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: Throne soils are used for livestock grazing, recreation and wildlife habitat. Vegetation includes blackbrush, creosotebush, green ephedra, banana yucca, red brome, winterfat and prickly pear.
DISTRIBUTION AND EXTENT: Northern Arizona; MLRA is 30. Throne series are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA
SERIES PROPOSED: Mohave County, Arizona; soil survey of Lake Mead National Recreation Area; 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 7 inches (A horizon).
Argillic horizon - The zone from 7 to 38 inches (Btk1, Btk2 and Btkz horizons).
Calcic horizon - The zone from 7 to 38 inches (Btk1, Btk2 and Btkz horizons).
Lithic contact - The boundary at 38 inches (R horizon).
National Cooperative Soil Survey
U.S.A.