LOCATION STAGECOACH AZ
Established Series
Rev. DRT/DLR
12/2014
STAGECOACH SERIES
The Stagecoach series consists of very deep, well drained soils formed in mixed alluvium. Stagecoach soils are on fan remnants with slopes of 0 to 60 percent. The mean annual precipitation is about 11 inches and the mean annual air temperature is about 63 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Typic Haplocalcids
TYPICAL PEDON: Stagecoach very gravelly sandy loam - rangeland (colors are for dry soil unless otherwise noted).
A--0 to 1 inch; light brown (7.5YR 6/4) very gravelly sandy loam, brown (7.5YR 4/4) moist; weak thin platy structure; soft, very friable, slightly sticky and nonplastic; few very fine and fine roots; common very fine vesicular and tubular pores; 45 percent gravel; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary (3 to 6 inches thick).
Bw--1 to 10 inches; brown (7.5YR 5/4) gravelly sandy loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine interstitial and tubular pores; 25 percent gravel; violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary (0 to 10 inches thick).
Bk1--10 to 24 inches; light brown (7.5YR 6/4) gravelly sandy loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine irregular and tubular pores; 25 percent gravel; violently effervescent; common faint continuous calcium carbonate coats on rock fragments; moderately alkaline (pH 8.4); gradual wavy boundary (10 to 20 inches thick).
Bk2--24 to 32 inches; light brown (7.5YR 6/4) very gravelly sandy loam, brown (7.5YR 4/4) moist; massive; soft, friable, slightly sticky and slightly plastic; few very fine and fine roots; violently effervescent; many distinct continuous calcium carbonate coats on rock fragments and few fine rounded soft masses of calcium carbonate; 45 percent gravel; moderately alkaline (pH 8.4); gradual wavy boundary (5 to 25 inches thick).
Bk3--32 to 60 inches; pinkish white (7.5YR 8/2) extremely gravelly sandy loam, pink (7.5YR 7/4) moist; massive; hard, very firm, slightly sticky and slightly plastic; violently effervescent; many distinct continuous calcium carbonate coats on rock fragments; 60 percent gravel; moderately alkaline (pH 8.4).
TYPE LOCATION: Pinal County, Arizona; 100 feet south and 2500 feet east of the northwest corner of section 21, T. 9 S., R. 2 E. Latitude of 32 degrees, 38 minutes, 08 seconds north and longitude of 112 degrees, 9 minutes, 38 seconds west.
RANGE IN CHARACTERISTICS:
Soil moisture: Intermittently moist in some part of the soil moisture control section during December-March and for more than 20 days cumulative during July-September. Driest during May and June. Typic aridic soil moisture regime.
Soil Temperature: 61 to 72 degrees F.
Rock Fragments: 35 to 85 percent
Depth to calcic: 2 to 25 inches
Clay content: averages less than 18 percent
Reaction: slightly to strongly alkaline
A horizon
Hue: 7.5YR, 10YR
Value: 4 to 8 dry, 3 to 7 moist
Chroma: 2 to 6, dry or moist
Bw and Bk horizons
Hue: 5YR, 7.5YR, 10YR
Value: 4 to 8 dry, 3 to 7 moist
Chroma: 1 to 6, dry or moist
Calcium carbonate equivalent: 5 to 20 percent
Texture: sandy loam, loam, coarse sandy loam, loamy sand
Some pedons contain C horizons of loamy sand with variable rock fragment content below 40 inches.
COMPETING SERIES: These are the
Alemeda (NM),
Chamberino (NM),
Dime (CA),
Nickel (NV),
Piquin (I)(NM), and
Railroad (NV) series. Alemeda soils have bedrock at depths of 20 to 40 inches. Chamberino soils average 17 to 27 percent clay in the control section. Dime, Nickel, and Railroad soils are in the
Mohave Desert and are moist in the soil moisture control section for less than 20 days cumulative between July and September. Piquin soils are inactive.
GEOGRAPHIC SETTING: Stagecoach soils are on fan remnants. Slope is 0 to 60 percent. They formed in alluvium from mixed sources. Elevation ranges from 1800 to 5000 feet. The mean annual precipitation ranges from 7 to 12 inches. The mean annual air temperature ranges from 59 to 70 degrees F. The frost-free period is 190 to 280 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Sahuarita,
Pinaleno, and
Palos Verdes soils. Sahuarita soils are fine-loamy. Palos Verdes and Pinaleno soils have argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately rapid permeability.
USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation is creosotebush, bush muhly, red grama, and Arizona cottontop.
DISTRIBUTION AND EXTENT: Southern Arizona and southern New Mexico. The series is extensive. Total extent is about 187,000 acres. MLRAs are 40, 41, and 42.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Beaver Creek Area, Arizona; 1965.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 1 inch (A horizon)
Calcic horizon - the zone from 10 to 60 inches (Bk1, Bk2, Bk3 horizons)
Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy, Twelfth Edition, 2014.
The type location for Stagecoach has been moved to a more accessible area within a modern soil survey (Tohono O'odham Nation). Stagecoach soils are typical of a 10 to 12 inch precipitation zone within MLRA 40 of the Sonoran Desert.
Updated competing series section 3/18/08, CEM
Revised for the correlation of AZ661, 2/2009, WWJ
Revised for the correlation of Graham County, AZ, Southwestern Part; March, 2011, WWJ
Revised for the correlation of White Sands Missile Range, New Mexico; October, 2014, NMS
National Cooperative Soil Survey
U.S.A.