LOCATION COCONINO AZEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Calciustepts
TYPICAL PEDON: Coconino extremely channery very fine sandy loam - woodland. (Colors are for dry soil unless otherwise noted.)
A--0 to 2 inches; reddish brown (5YR 5/3) extremely channery very fine sandy loam, reddish brown (5YR 4/3) moist; weak medium platy structure parting to weak fine granular; soft, very friable, nonsticky and nonplastic; common very fine roots; common very fine irregular pores; 65 percent channers, 15 percent cobble, and 5 percent stones as surface lag layer; violently effervescent; slightly alkaline (pH 7.8); abrupt smooth boundary. (1 to 3 inches thick)
Bw1--2 to 6 inches; reddish brown (5YR 5/4) channery loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic; many very fine roots; common very fine tubular pores; 15 percent channers and 15 percent gravel; violently effervescent; slightly alkaline (pH 7.8); abrupt wavy boundary. (3 to 5 inches thick)
Bw2--6 to 13 inches; light reddish brown (2.5YR 6/4) gravelly loam, reddish brown (2.5YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; many very fine and few medium roots; common very fine tubular pores; 15 percent gravel and 10 percent cobble; violently effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (6 to 9 inches thick)
Bk--13 to 26 inches; light reddish brown (2.5YR 6/4) and pink (5YR 7/3) gravelly loam, reddish brown (2.5YR 4/4) and reddish brown (5YR 5/4) moist; moderate coarse subangular blocky structure; slightly hard, friable, slightly sticky and plastic; many very fine and common coarse roots; common very fine tubular pores; 15 percent fine gravel; common fine soft calcium carbonate masses and coatings on ped faces; violently effervescent, 20 percent calcium carbonate equivalent; slightly alkaline (pH 7.8); abrupt wavy boundary. (8 to 15 inches thick)
Cr--26 inches; calcareous sandy shale.
TYPE LOCATION: Coconino County, Arizona; on the Hualapai Indian Reservation; approximately 2200 feet east and 2500 feet north of the southwest corner of Section 24, T. 26 N., R. 10 W.; about .5 mile southeast of Metuck Tank.
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in the soil moisture control section during December-March and July-September. Driest during May and June. Aridic ustic soil moisture regime.
Soil Temperature: 54 to 57 degrees F.
Rock fragments: 10 to 25 percent, dominantly gravel
Calcium carbonate equivalent: 15 to 25 percent in the control section
Clay content: 18 to 27 percent in the particle-size control section
Depth to bedrock: 20 to 40 inches
A horizon
Chroma: 3 through 4, dry or moist
Bw horizon
Hue: 2.5YR, 5YR
Value: 4 through 6 dry, 3 or 4 moist
Texture: very fine sandy loam, loam
Bk horizon
Hue: 2.5YR, 5YR
Value: 4 through 6 dry, 3 or 4 moist
Chroma: 3 through 6, dry or moist
Texture: very fine sandy loam, loam, sandy clay loam
COMPETING SERIES: This is the Cibeque (AZ), Kandrix (CO) and Quartermaster (AZ) series. Cibeque and Kandrix soils are very deep. In addition, Kandrix soils are in LRR-G and are more moist in May and June. Quartermaster soils have a petrocalcic horizon at moderate depths.
GEOGRAPHIC SETTING: Coconino soils are on hills of plateaus and mesas. They formed in colluvium and residuum from interbedded sandstone, limestone, and siltstone. Slopes range from 2 to 15 percent. Elevation is 5300 to 5800 feet. The mean annual precipitation is 14 to 16 inches. The mean annual air temperature is 52 to 55 degrees F. The frost-free period is 135 to 175 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Metuck and Wodomont soils. Metuck and Wodomont soils are shallow to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Coconino soils are used for grazeable woodland, fuelwood gathering, and wildlife habitat. The present vegetation is Utah juniper, pinyon, blue grama, Fendler threeawn, black grama and Fremont barberry.
DISTRIBUTION AND EXTENT: Northern Arizona. The Coconino series is not extensive. MLRA 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Coconino County, Arizona; Soil survey of the Hualapai Indian Reservation; 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 2 inches (A horizon)
Cambic horizon - The zone from 2 to 13 inches (Bw1, Bw2 horizons)
Calcic horizon - The zone from 13 to 26 inches (Bk horizon)
Paralithic contact - The boundary at 26 inches (Cr horizon)