LOCATION GUANO OREstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive, frigid, shallow Xeric Haplargids
TYPICAL PEDON: Guano gravelly sandy loam - rangeland - on a 2 percent slope at an elevation of 4950 feet. (Colors are for dry soil unless otherwise stated.)
A--0 to 3 inches; pale brown (10YR 6/3) gravelly sandy loam, brown (10YR 4/3) moist; strong coarse platy structure; slightly hard, friable, nonsticky and slightly plastic; common fine and medium roots; many very fine, fine and medium vesicular pores; 15 percent gravel; slightly alkaline (pH 7.8); abrupt smooth boundary. (2 to 8 inches thick)
Bt--3 to 11 inches; yellowish brown (10YR 5/4) gravelly clay loam, dark yellowish brown (10YR 3/4) moist; medium fine angular blocky structure; hard, firm, moderately sticky and moderately plastic; common fine and medium roots; common very fine and fine irregular tubular pores; common distinct clay films on faces of peds; 15 percent gravel; slightly alkaline (pH 7.8); abrupt smooth boundary. (6 to 12 inches thick)
Cr--11 inches; weathered tuffaceous sedimentary rocks.
TYPE LOCATION: Harney County, Oregon, about 500 feet west and 2,300 feet south of the northeast corner of section 29, T. 36 S., R. 30 E., on the Fish Fin Rim quadrangle. (Latitude 42 degrees, 25 minutes, 23 seconds N, Longitude 119 degrees, 12 minutes, 29 seconds W)
RANGE IN CHARACTERISTICS: The soils are dry in all parts of the moisture control section for one-half to three-fourths of the time when the soil temperature is greater than 41 degrees F. The mean annual soil temperature is 45 to 47 degrees F. The solum thickness and depth to a paralithic contact is 10 to 20 inches. The particle-size control section averages 0 to 25 percent rock fragments mainly as gravel, and 18 to 30 percent clay.
The A horizon has value of 5 or 6 dry, 3 or 4 moist and chroma of 3 or 4 moist and dry. Rock fragment content of 15 to 35 percent. Clay content is 10 to 18 percent. Reaction is slightly to moderately alkaline.
The Bt horizon has hue of 10YR or 7.5YR, value of 5 or 6 dry, 3 to 5 moist and chroma of 3 to 6 moist and dry. It is sandy clay loam, loam and clay loam. Rock fragment content is 0 to 25 percent. Clay content is 18 to 35 percent. Reaction is slightly to moderately alkaline.
COMPETING SERIES: There are no competing series in this family.
GEOGRAPHIC SETTING: Guano soils are are on dissected tablelands and have slopes of 2 to 15 percent. The soils formed in eolian sands and loess over residuum from tuffaceous sedimentary rocks. Elevations are 4,600 to 5,000 feet. The climate is characterized by cold, moist winters and hot, dry summers. The mean annual precipitation is 8 to 10 inches. The mean annual temperature is 43 to 45 degrees F. The frost free period is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brace, Raz, and Rinconflat soils. Brace soils are moderately deep to a duripan. Raz soils are shallow to a duripan. Raz and Brace soils are on tablelands. Rinconflat soils are very deep soils on alluvial fan terraces.
DRAINAGE AND PERMEABILITY: Well drained, moderately slow permeability.
USE AND VEGETATION: The soils are used for livestock grazing and wildlife habitat. Potential native vegetation is Wyoming big sagebrush, Thurber needlegrass, indian ricegrass, and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Hills in southeast Oregon; MLRA 24, 23. Series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Harney County, Oregon, 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
- Ochric epipedon
- Argillic horizon: from 3 to 11 inches (Bt horizon)
- Particle-size control section - from 0 to 11 inches (A and Bt horizons) averages about 23 clay.