LOCATION THUNDERBIRD AZ+NM NVEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Aridic Argiustolls
TYPICAL PEDON: Thunderbird very stony clay loam - grazeable woodland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; grayish brown (10YR 5/2) very stony clay loam, dark grayish brown (10YR 4/2) moist; strong fine granular structure; slightly hard, friable, sticky and plastic; few fine roots; many fine irregular pores; 35 percent stones and 20 percent gravel; slightly alkaline; abrupt wavy boundary. (2 to 4 inches thick)
Bt1--2 to 6 inches; brown (7.5YR 4/2) clay loam, dark brown (7.5YR 3/2) moist; moderate fine angular blocky structure; hard, firm, sticky and plastic; few faint clay films on faces of peds; many fine roots; common fine tubular pores; 10 percent cobble and gravel; slightly alkaline; clear wavy boundary. (3 to 8 inches thick)
Bt2--6 to 19 inches; brown (7.5YR 4/2) clay, dark brown (7.5YR 3/2) moist; strong medium angular blocky structure; extremely hard, very firm, very sticky and very plastic; few faint continuous clay films on faces of peds; common fine roots; few fine tubular pores; 10 percent cobble and gravel; moderately alkaline; clear wavy boundary. (8 to 17 inches thick)
Btk--19 to 24 inches; brown (7.5YR 5/4) clay, brown (7.5YR 4/4) moist; strong fine angular blocky structure; extremely hard, very firm, very sticky and very plastic; few faint continuous clay films on faces of peds; few calcium carbonate accumulations; common medium roots; few fine tubular pores; 10 percent cobble and gravel; slightly effervescent; moderately alkaline; abrupt irregular boundary. (7 to 11 inches thick)
2R--24 inches; basalt.
TYPE LOCATION: Coconino County, Arizona; about 10 miles northwest of Ashfork; 500 feet south of the northwest corner of Section 1, T. 22 N., R. 4 W.
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: 47 to 58 degrees F.
Rock Fragments: Averages 5 to 25 percent; can range to 85 percent in any one horizon
Depth to bedrock: 20 to 40 inches
Reaction: Neutral to moderately alkaline
Hue: 7.5YR, 10YR
Value: 4 or 5 dry, 2, 3 or 4 moist
Chroma: 2 or 3, dry or moist
Hue: 5YR, 7.5YR, 10YR
Value: 3 through 7 dry, 2 through 6 moist
Chroma: 1 through 6, dry or moist
Texture: Loam, clay loam, clay, silty clay (25 to 60 percent clay)
Calcium carbonate: Less than 15 percent calcium carbonate equivalent as filaments, small accumulations or disseminated
COMPETING SERIES: These are the Bethune (CO), Blackpipe (SD), Boneek (SD), Boquillas (AZ), Chapin (CO), Collbran (CO), Collide (CO), Emigrant (WY), Huggins (SD), Kube (SD), Leyden (CO), Loma (CO), Nuncho (WY), Nunn (CO), Querc (WY), Raku (CO), Rednun (CO), Richfield (KS), Ryus (KS), Savo (SD), Showlow (AZ), Standley (CO), Weld (CO) and Wormser (CO) series. Bethune, Blackpipe, Boquillas, Emigrant, Huggins, and Leyden soils have a paralithic contact at depths of 20 to 40 inches. Boneek, Collbran, Collide, Kube, Loma, Nuncho, Nunn, Querc, Raku, Rednun, Richfield, Ryus, Savo, Showlow, Standley and Weld soils do not have bedrock at depths less than 40 inches. Chapin and Wormser soils formed in parent material derived from sandstone.
GEOGRAPHIC SETTING: Thunderbird soils are on ridges, hills and basalt capped mesas and have slopes of 0 to 60 percent. These soils formed in alluvium from basalt and pyroclastics. Elevations range from 4,000 to 7,500 feet. The mean annual precipitation is 14 to 18 inches. The mean annual air temperature is 45 to 56 degrees F. The frost-free period is 120 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Ashfork and Boquillas soils and the Cabezon, Cross, Showlow, and Springerville soils. Cabezon and Cross soils have bedrock at depths less than 20 inches. Showlow soils are more than 40 inches deep. Springerville soils have intersecting slickensides.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; slow or very slow permeability.
USE AND VEGETATION: Thunderbird soils are used for livestock grazing, wildlife habitat and fuelwood production. The present vegetation is juniper, blue grama, sideoats grama, algerita, tobosa, mimosa, and sand dropseed.
DISTRIBUTION AND EXTENT: Arizona, New Mexico and Nevada. This series is extensive. MLRA is 35 and 39.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Yavapai County Area, Arizona, Western Part; 1968.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the 0 to 19 inches (A, Bt1, Bt2 horizons)
Argillic horizon - The zone from 2 to 24 inches (Bt1, Bt2, Btk horizons)
Lithic contact - The boundary at 24 inches (2R horizon)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy Tenth Edition, 2006.