LOCATION AYRES OREstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic, shallow Argiduridic Durixerolls
TYPICAL PEDON: Ayres very cobbly loam, on a 6 percent slope, rangeland. (Colors are for moist soils unless otherwise noted.)
A-- 0 to 3 inches; very dark grayish brown (10YR 3/2) very cobbly loam, brown (10YR 5/3) dry; moderate very fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and few fine roots; common very fine interstitial pores; 25 percent gravel and 20 percent cobbles; slightly alkaline (pH 7.6); clear wavy boundary. (3 to 5 inches thick)
AB-- 3 to 8 inches; dark brown (10YR 3/3) very cobbly loam, yellowish brown (10YR 5/4) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and plastic; common very fine, few fine and medium roots; common very fine tubular pores; 25 percent gravel and 30 percent cobbles; slightly alkaline (pH 7.8); clear wavy boundary. (4 to 7 inches thick)
Bt1-- 8 to 12 inches; dark yellowish brown (10YR 3/4) very cobbly loam, yellowish brown (10YR 5/6) dry; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine, few fine and medium roots; few very fine tubular pores; few faint clay films on faces of peds; 25 percent gravel and 20 percent cobbles; slightly alkaline (pH 7.8); clear wavy boundary.
Bt2-- 12 to 15 inches; dark yellowish brown (10YR 3/4) extremely cobbly clay loam, yellowish brown (10YR 5/6) dry; massive; slightly hard, friable, moderately sticky and moderately plastic; few very fine roots; few very fine tubular pores; common discontinuous faint clay films on faces of peds; 30 percent gravel and 45 percent cobbles; slightly alkaline (pH 7.8); abrupt wavy boundary. (Combined thickness of Bt horizon ranges from 3 to 10 inches.)
Bqm-- 15 to 60 inches; indurated pan, with cemented subrounded gravel and cobble fragments.
TYPE LOCATION: Crook County, Oregon; located 600 feet south and 2000 feet east of the NW corner of section 31, T. 15 S., R. 15 E.; about 2 miles southeast of the community of Powell Butte.
RANGE OF CHARACTERISTICS: The soils are dry for one-half to three-fourths of the time when the soil temperature is above 41 degrees F. They are usually dry, and are dry in the moisture control section for 90 to 120 cumulative days following the summer solstice. The mean annual soil temperature is 50 to 54 degrees. Depth to the duripan is 10 to 20 inches. Depth to bedrock is greater than 60 inches. The particle-size control section averages over 50 percent rock fragments.
The A horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry. It contains 15 to 30 percent rounded gravel and 20 to 30 percent rounded cobbles.
The Bt horizon has value of 3 or 4 moist, 5 or 6 dry, and chroma of 3 or 4 moist, and 4 through 6 dry. It is clay loam, loam, or sandy clay loam, and contains 25 to 35 percent clay. It contains 20 to 35 percent rounded gravel and 20 to 50 percent rounded cobbles.
The Bqm or Bkqm horizon is indurated or very strongly cemented to a depth of 40 inches or more.
COMPETING SERIES: This is the Gorskel series. Gorskel soils average 35 to 50 percent rock fragments in the particle-size control section.
GEOGRAPHIC SETTING: Ayres soils are on alluvial fans and fan remnants at elevations of 3,100 to 3,800 feet. Slopes range from 3 to 20 percent. These soils formed in colluvium derived from rhyolite with an influence of volcanic ash in the surface. The climate is characterized by cool moist winters and hot dry summers. The mean annual precipitation is 9 to 12 inches, the mean annual temperature is 48 to 52 degrees F., and the frost-free period is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ayresbutte, Deschutes, Redmond, Stukel, and Stukmond. Ayresbutte is moderately deep to a duripan and has more surface ash. Redmond and Deschutes are moderately deep to bedrock and are on adjacent lava plains. Stukel and Stukmond are shallow to bedrock and are on adjacent lava plains.
DRAINAGE AND PERMEABILTY: Well drained, permeability is moderately slow above the duripan and very slow through the duripan.
USE AND VEGETATION: Ayres soils are used mainly for livestock grazing wildlife habitat. The native vegetation is Idaho fescue, bluebunch wheatgrass, low sagebrush, and western juniper.
DISTRIBUTION AND EXTENT: Central Oregon; MLRA 10, John Day area. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Prineville Area, Crook County, Oregon, 1963.
REMARKS: Diagnostic horizons and features in this pedon include:
Mollic epipedon - the zone from the surface to a depth of 8 inches (A and AB horizons)
Argillic horizon - from a depth of 8 to 15 inches (Bt horizon)
Indurated duripan - from a depth of 15 to 60 inches (Bqm horizon)
ADDITIONAL DATA: Characterization data on one profile (S55 Oreg-7-3) reported in Soil Survey of Prineville Area, Oregon.