LOCATION COOPEROPOLIS OR
Established Series
Rev. SCW/TDT
11/2010
COOPEROPOLIS SERIES
The Cooperopolis series consists of shallow, well drained soils on north-facing side slopes or tilted plateaus. They formed in ash and loess over fractured volcanic tuff. Slopes are 2 to 50 percent. The mean annual precipitation is about 10 inches, and the mean annual temperature is about 50 degrees F.
TAXONOMIC CLASS: Loamy, mixed, superactive, mesic Aridic Lithic Argixerolls
TYPICAL PEDON: Cooperopolis ashy loam - rangeland, on a 30 percent north-facing slope at an elevation of 1,560 feet. (When described on July 22, 1998, the soil was dry throughout. Colors are moist colors unless otherwise noted.)
A--0 to 2 inches; very dark grayish brown (10YR 3/2) ashy loam, brown (10YR 5/3) dry; weak medium subangular blocky and weak very fine granular structure; soft, very friable, slightly sticky and slightly plastic; few fine and many very fine roots; few fine and common very fine irregular pores; 5 percent gravel; neutral (pH 6.7); abrupt smooth boundary. (2 to 7 inches thick)
2Bt--2 to 12 inches; dark brown (10YR 3/3) clay loam, brown (10YR 5/3) dry; moderate medium and coarse angular blocky structure; hard, firm, moderately sticky and very plastic; few fine and common very fine roots; few fine and common very fine tubular pores; many distinct clay films on ped faces; 5 percent gravel; neutral (pH 7.3); abrupt wavy boundary. (4 to 13 inches thick)
2Bk--12 to 14 inches; dark brown (10YR 3/3) extremely gravelly clay loam, brown (10YR 5/3) dry; moderately fine and medium subangular blocky structure; hard, firm, moderately sticky and very plastic; carbonates coating the underside of rocks; strongly effervescent; 60 percent gravel; moderately alkaline (pH 8.4); abrupt wavy boundary. (0 to 3 inches thick)
2R--14 inches; fractured volcanic tuff
TYPE LOCATION: Wheeler County, Oregon, located about one mile east of the town of Clarno; 2,300 feet west and 2,000 feet south of the northeast corner of section 33, T. 7 S., R. 19 E. Latitude 44 degrees, 55 minutes, 00 seconds North; Longitude 120 degrees, 27 minutes, 04 seconds West.
RANGE IN CHARACTERISTICS: The soil moisture control section is dry in all parts for one-half to three-fourths of the time when the soil temperature is above 41 degrees F. (aridic). The mean annual soil temperature is 47 to 54 degrees F. The mollic epipedon is 7 to 15 inches thick. Depth to bedrock is 10 to 20 inches. When present, depth to secondary carbonates is 10 inches or more. The particle-size control section averages less than 15 percent rock fragments.
The A horizon has chroma of 2 or 3 moist and dry. It is loam with 20 to 27 percent clay. It has 0 to 15 percent gravel. It has 5 to 20 percent glass with acid oxalate aluminum plus one-half the iron of 0.2 to 0.5. It is neutral to moderately alkaline.
The 2Bt horizon has value of 3 or 4 moist and chroma of 3 or 4 moist and dry. It is clay loam with 27 to 35 percent clay. It has 0 to 15 percent gravel. It is neutral to moderately alkaline.
The 2Bk horizon, when present, has colors similar to the 2Bt horizon. It is clay loam with 30 to 40 percent clay. It has 40 to 70 percent rock fragments. It has less than 1 percent organic matter.
COMPETING SERIES: These are the
Adinot,
Borland,
Jilson,
Laric,
Malinda,
Mcquarrie,
Pass Canyon,
Terca, and
Yrtneg series. All these soils except Yrtneg lack vitrandic properties in the surface horizons. Adinot soils have more than 35 percent clay in the lower part of the argillic horizon. Borland soils have a xeric moisture regime. Jilson soils have a xeric moisture regime. Laric soils have 15 to 35 percent rock fragments in the control section and has a soil reaction of neutral or slightly alkaline. Malinda soils have a xeric moisture regime. McQuarrie soils have a xeric moisture regime. Pass Canyon soils have a xeric moisture regime. Terca soils have 15 to 35 percent rock fragments in the control section and has a soil reaction of slightly alkaline or neutral. Yrtneg soils have a xeric moisture regime.
GEOGRAPHIC SETTING: Cooperopolis soils are on north-facing slopes of tilted plateaus or side slopes. This soil formed in ash and loess over fractured volcanic tuff. Slopes are 2 to 50 percent. Elevation is 1,400 to 3,000 feet. The climate is semi-arid with cool, moist winters and hot, dry summers. The mean annual precipitation is 9 to 12 inches, and the mean annual temperature is 45 to 52 degrees F. The frost-free period is 90 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Ruckles and
Simas soils. Ruckles soils are clayey-skeletal, andic properties in the surface layer, and are found on adjacent south slopes. Simas soils are in the fine family, very deep, and are on footslopes below the Cooperopolis soils.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: This soil is used for livestock grazing and wildlife habitat. The potential native vegetation is bluebunch wheatgrass, Idaho fescue, Thurber needlegrass, basin big sagebrush, and broom snakeweed.
DISTRIBUTION AND EXTENT: East-central Oregon, MLRA B-10. This series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: John Day Fossil Beds National Monument, Oregon, 2000.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from surface to 12 inches (A and 2Bt horizons)
Argillic horizon - 2 to 12 inches (2Bt horizon)
Secondary carbonates - 12 to 14 inches (2Bk horizon)
Aridic moisture regime
Particle-size control section - 0 to 14 inches averages 13 percent rock fragments
"Vitri" feature - the acid oxalate aluminum plus one-half of the acid oxalate iron times 60 plus volcanic glass is 22 from 0 to 2 inches; it is assumed there is more glass in the coarser fine earth fractions.
ADDITIONAL DATA: Partial laboratory data is available on this soil. See reference samples S98OR-069-003-(1-2) and S98OR-069-013-(1-2).
National Cooperative Soil Survey
U.S.A.