LOCATION ASHFORK AZEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Calcidic Argiustolls
TYPICAL PEDON: Ashfork gravelly clay loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; brown (10YR 5/3) gravelly clay loam, dark brown (7.5YR 3/2) moist; weak thin platy structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine roots; many very fine and fine vesicular pores; 20 percent gravel; moderately alkaline (pH 8.0); clear smooth boundary. (2 to 3 inches thick)
Bt--2 to 7 inches; dark reddish brown (5YR 3/3) clay, dark reddish brown (5YR 3/3) moist; moderate medium and coarse prismatic structure parting to moderate fine subangular blocky; hard, firm, moderately sticky and moderately plastic; common very fine and fine roots; few very fine tubular and interstitial pores; common faint clay films on faces of peds and in pores; 10 percent gravel; moderately alkaline (pH 8.4); clear wavy boundary. (4 to 8 inches thick)
Btk--7 to 12 inches; pale brown (10YR 6/3) clay, brown (10YR 4/3) moist; weak fine subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine tubular and interstitial pores; common faint clay films on faces of peds and in pores; 10 percent gravel; common fine and medium soft lime masses; strongly effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (4 to 9 inches thick)
Bk--12 to 17 inches; light yellowish brown (10YR 6/4) clay loam, brown (7.5YR 5/4) moist; weak fine subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; few very fine and fine roots; common very fine tubular pores; 10 percent gravel; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (5 to 7 inches thick)
2Ck--17 to 30 inches; very pale brown (10YR 8/2) stony loam, very pale brown (10YR 7/3) moist; massive; slightly hard, very friable, slightly sticky and moderately plastic; few very fine and fine roots; common very fine tubular pores; violently effervescent with approximately 55 percent calcium carbonate; 30 percent stones; moderately alkaline (pH 8.4); abrupt smooth boundary. (5 to 13 inches thick)
3R--30 to 34 inches; fractured vesicular basalt; common carbonates in joints.
TYPE LOCATION: Coconino County, Arizona; 100 feet south and 700 feet east of the NW corner of section 33, T. 26 N., R. 5 E.
RANGE IN CHARACTERISTICS:
Depth to bedrock: 20 to 40 inches
Depth to calcic horizon: 10 to 20 inches
Soil moisture: Intermittently moist in some part of the SMCS from July to September and December to February. Aridic ustic moisture regime.
Soil temperature: 50 to 55 degrees F.
Rock fragments: 10 to 35 percent coarse fragments
A horizon
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist
Bt & Bk horizons
Hue: 5YR to 10YR
Value: 3 to 6 dry, 2 to 5 moist
Chroma: 2 or 3, dry or moist
Texture: clay loam, clay
Reaction: moderately alkaline or strongly alkaline
Calcium carbonate equivalent: 15 percent
2Ck horizons
Hue: 7.5YR or 10YR
Value: 6 to 8 dry, 5 to 7 moist
Chroma: 2 to 4, dry or moist
Texture: stony loam, stony clay loam
Reaction: moderately alkaline or strongly alkaline
Calcium carbonate equivalent: 40 to 60 percent
COMPETING SERIES: These are the Mcorreon (NM) and Torreon (NM) series. Mcorreon and Torreon soils are very deep.
GEOGRAPHIC SETTING: Ashfork soils are at elevations of 5,000 to 6,800 feet on hills. Slopes are 1 to 15 percent. The soils formed in alluvium and colluvium derived from basalt and pyroclastics including tuff, volcanic breccias and agglomerate. The mean annual air temperature ranges from 49 to 54 degrees F. The average annual precipitation ranges from 12 to 14 inches and occurs as thunderstorms in July, August and September and as rain and snow in the winter. The frost-free period ranges from 130 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Aut, Boysag, Cross, Springerville, Winona and Ziegler soils. Aut soils do not have an argillic horizon. Boysag, Cross and Winona soils are less than 20 inches deep to a lithic contact. Springerville soils crack when dry and do not have a calcic horizon. Ziegler soils are moderately deep over cinders.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; slow permeability.
USE AND VEGETATION: Used primarily for livestock grazing. Vegetation is mainly blue grama, galleta, bottlebrush squirreltail, western wheatgrass, snakeweed, and scattered juniper and pinyon pine.
DISTRIBUTION AND EXTENT: Northern Arizona. The soils are moderately extensive. MLRA is 35 & 39.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Coconino County Area, Central Part, Arizona, 1980.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 7 inches (A & Bt horizons)
Argillic horizon - the zone from 2 to 12 inches (Bt & Btk horizons)
Calcic horizon - the zone from 17 to 30 inches (2Ck horizon)
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003