LOCATION ASHCREEK AZEstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Torrertic Haplustolls
TYPICAL PEDON: Ashcreek clay - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 6 inches; dark brown (7.5YR 3/2) clay, very dark brown (7.5YR 2.5/2) moist; moderate very fine and fine subangular blocky structure parting to weak fine granular; hard, very friable, very sticky and very plastic; many very fine and fine roots; many very fine tubular pores; noneffervescent; neutral (pH 6.8); clear smooth boundary. (1 to 8 inches thick)
Bw1--6 to 36 inches; dark brown (7.5YR 3/2) clay, black (7.5YR 2.5/1) moist; strong medium and coarse wedges parting to strong fine and medium angular blocky structure; hard, very friable, very sticky and very plastic; common very fine and fine roots; many very fine tubular pores; many distinct pressure faces; noneffervescent; neutral (pH 6.8); abrupt wavy boundary.
Bw2--36 to 52 inches; dark brown (7.5YR 3/2) cobbly clay, dark brown (7.5YR 3/2) moist; moderate fine and medium wedges parting to moderate fine and medium angular blocky structure; hard, very friable, very sticky and very plastic; few very fine and fine roots; many fine irregular pores; many distinct pressure faces; 5 percent gravel and 15 percent cobbles; noneffervescent; neutral (pH 7.0); abrupt wavy boundary. (Combined thickness of Bt horizons is 40 to 50 inches)
2Btb--52 to 60 inches; reddish brown (5YR 4/3) clay, dark reddish brown (5YR 3/4) moist; strong fine and medium subangular blocky structure; hard, very friable, very sticky and very plastic, few very fine and fine roots; many very fine tubular pores; many distinct clay films on rock fragments and ped faces; common organic coats on faces of peds; 10 percent gravel; noneffervescent; neutral (pH 7.2).
TYPE LOCATION: Cochise County, Arizona; located about 2,200 feet north and 200 feet west of the southeast corner of section 9, Township 20 S., Range 28 E.; Bruno Peak topography map; latitude 33 degrees, 42 minutes, 20 seconds North and longitude 109 degrees, 28 minutes, 40 seconds West.
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.
Soil Temperature: 59 to 64 degrees F.
Rock fragments: less than 25 percent gravel and cobbles
Soil cracks: many vertical cracks 0.5 to 2 inches wide from the surface to 36 inches or more
Reaction: slightly acid to neutral
Effervescence: noneffervescent throughout
Clay content: greater than 35 percent in the control section
Organic matter: 1 to 3 percent
A horizon
Hue: 7.5YR, 5YR
Value: 3 through 6 dry, 2 or 3 moist
Chroma: 1 through 3, dry or moist
Texture: clay, clay loam, silty clay loam
Bw horizon
Hue: 7.5YR, 5YR
Value: 3 or 5 dry, 2 through 4 moist
Chroma: 1 through 3, dry or moist
Texture: clay, silty clay
2Btb horizon
Hue: 7.5YR, 5YR
Value: 3 or 4, dry or moist
Chroma: 2 through 4, dry or moist
Texture: clay
COMPETING SERIES: These are the Cazador (I)(AZ) and Phantom (TX) series. Cazador soils are inactive. Phantom soils do not have buried horizons and are effervescent throughout.
GEOGRAPHIC SETTING: The Ashcreek soils are in the Chihuahuan desert on alluvial fans, flood plains, and inset fans at elevations of 4,200 to 6,200 feet. Slope ranges from 0 to 10 percent. These soils formed from mixed alluvium. The mean annual precipitation is 16 to 20 inches and occurs as thunderstorms during July to September and as gentle rains during December and January. The mean annual air temperature is 57 to 62 degrees F. The frost-free period is 160 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blacktail, Cherrycow, Stanford, and Terrarossa soils. Blacktail, Cherrycow, and Terrarossa soils have clay content greater than 35 percent and are on fan terraces or hills. Stanford soils have less than 35 percent clay.
DRAINAGE AND PERMEABILITY: Well drained; medium to high runoff; very slow permeability.
USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Vegetation includes tobosa, black grama, sideoats grama, vine mesquite, cane beardgrass, and blue grama.
DISTRIBUTION AND EXTENT: Southeastern Arizona portion of the Chihuahuan Desert. MLRAs are 38 and 41. Ashcreek soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Cochise County, Arizona; Soil Survey of Cochise County, Arizona, Douglas -Tombstone Part; 2000.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 36 inches (A and Bw1 horizons)
Torrertic feature - wedge shape aggregates from a depth of 6 to 52 inches (Bw1 and Bw2 horizons)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006
Updated competing series section 4/11/2008, CEM
Revised for the correlation of AZ675, 5/2009, WWJ