LOCATION COPPERFIELD OREstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Pachic Argixerolls
TYPICAL PEDON: Copperfield very cobbly silt loam - rangeland on a 75 percent north-east facing slope at an elevation of 2080 feet. (Colors are for moist soil unless otherwise noted.)
A1--0 to 8 inches; black (10YR 2/1) very cobbly silt loam, dark grayish brown (10YR 4/2) dry; moderate very fine and fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many fine and medium roots; many very fine and fine and common medium tubular pores; 25 percent cobbles and 20 percent gravel; neutral (pH 6.6); clear smooth boundary.
A2--8 to 19 inches; very dark gray (10YR 3/1) very gravelly silt loam, dark grayish brown (10YR 4/2) dry; moderate fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine and common medium roots; many very fine and fine and common medium tubular pores; 40 percent gravel and 10 percent cobbles; neutral (pH 6.6); gradual smooth boundary. (Combined thickness of the A horizon is 17 to 24 inches)
Bw1--19 to 28 inches; very dark grayish brown (10YR 3/2) very gravelly silty clay loam, grayish brown (10YR 5/2) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and few medium roots; many very fine and fine and common medium tubular pores; 35 percent gravel and 15 percent cobbles; neutral (pH 6.8); clear smooth boundary.
Bw2--28 to 42 inches; dark brown (10YR 3/3) very cobbly silty clay loam, brown (10YR 5/3) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; many very fine and fine and few medium tubular pores; 35 percent cobbles and 20 percent gravel; neutral (pH 6.8); gradual smooth boundary. (Combined thickness of the Bw horizon is 20 to 30 inches)
2Bt1--42 to 49 inches; dark grayish brown (10YR 4/2) extremely cobbly silty clay, pale brown (10YR 6/3) dry; moderate medium and coarse subangular blocky structure; hard, firm, sticky and plastic; few fine roots; many very fine and fine tubular pores; common distinct clay films on ped faces and lining pores; 50 percent cobbles and 15 percent gravel; neutral (pH 7.0); gradual wavy boundary. (6 to 10 inches thick)
2Bt2--49 to 60 inches; dark grayish brown (10YR 4/2) extremely cobbly clay, pale brown (10YR 6/3) dry; moderate medium and coarse subangular blocky structure; hard, firm, sticky and plastic; few fine roots; many very fine and fine tubular pores; many prominent clay films on ped faces and lining pores; 50 percent cobbles and 15 percent gravel; neutral (pH 7.0).
TYPE LOCATION: Baker County, Oregon; located about 1 mile southwest of Oxbow Dam and 300 feet above Oxbow Dam reservoir, 1320 feet south and 1440 feet east of the NW corner of section 16, T. 7 S., R. 48 E. (Latitude 44 degrees, 57 minutes, 39 seconds N, Longitude 116 degrees, 51 minutes, 15 seconds W)
RANGE IN CHARACTERISTICS: These soils are usually moist, but are dry in the moisture control section for 60 to 80 consecutive days following the summer solstice. The mean annual soil temperature is 47 to 51 degrees F. Depth to bedrock is typically greater than 60 inches but may range between 40 and 60 inches in some pedons. The reaction in the subsoil is slightly acid to neutral. The thickness of the mollic epipedon and depth to the 2Bt horizon (argillic) is 40 to 50 inches. The 10 to 40 inch particle-size control section averages 25 to 35 percent clay and 40 to 70 percent rock fragments.
The A horizon has value of 2 or 3 moist, 3 or 4 dry and chroma of 1 or 2 moist and dry. It has 15 to 40 percent gravel, 10 to 25 percent cobbles and 0 to 10 percent stones.
The Bw horizon has value of 3 or 4 moist, 4 or 5 dry and chroma of 2 or 3 moist and dry. It is silty clay loam to clay loam with 27 to 35 percent clay. It has 20 to 35 percent gravel, 15 to 40 percent cobbles and 0 to 15 percent stones.
The 2Bt horizon has value of 3 to 5 moist, 5 or 6 dry and chroma of 2 or 3 moist and dry. It is silty clay, clay or silty clay loam with 35 to 50 percent clay. It has 10 to 30 percent gravel, 35 to 55 percent cobbles, and 0 to 5 percent stones.
The 2C horizon, when present, has value of 5 or 6 moist, 6 or 7 dry and chroma of 3 or 4 moist and dry. It is loam or clay loam with 20 to 30 percent clay. It has 10 to 20 percent gravel and 40 to 55 percent cobbles and 0 to 5 percent stones.
COMPETING SERIES: These are the Carrcreek, Hyrum, Jadpor, McDaniel, and Sagley series. All of the above series have the top of the argillic horizon above 40 inches. Carrcreek soils have a mean annual soil temperature of 52 to 59 degrees F. and a mollic epipedon 20 to 35 inches thick. Jadpor soils are dry for more than 90 consecutive days following the summer solstice. McDaniel soils have a mollic epipedon 21 to 30 inches thick. Sagley soils are 40 to 60 inches deep to bedrock.
GEOGRAPHIC SETTING: Copperfield soils are on steep, meta-stable and active north-facing side slopes of low elevation hills and canyon walls. Elevations are 800 to 3,400 feet. Slope is 30 to 90 percent. The soils formed in colluvium derived dominantly from basalt. The climate is characterized by cool wet winters and hot dry summers. The mean annual precipitation is 12 to 20 inches. The mean annual temperature is 45 to 50 degrees F. The frost-free period is 100 to 145 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Emily, Gwinly and Immig soils. Emily soils are forested, are on footslopes of mountains, and have base saturation less than 75 percent in some part of the upper 30 inches of the soil profile. Gwinly soils are shallow and clayey-skeletal. Immig soils are 20 to 40 inches deep and clayey-skeletal. Gwinly and Immig soils are on hills and canyonsides.
DRAINAGE AND PERMEABILITY: Well drained; permeability is slow.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. Potential native vegetation is mainly Idaho fescue and bluebunch wheatgrass with minor amounts of mockorange, Saskatoon serviceberry, blue elderberry, rose and hawthorn.
DISTRIBUTION AND EXTENT: Northeastern Oregon, MLRA 9. The soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Baker County Area, Oregon; 1988.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface of the soil to a depth of approximately 42 inches (A1, A2, Bw horizons).
Argillic horizon - the zone from 42 to 60 inches (2Bt1, 2Bt2 horizons).
Pachic feature - mollic epipedon to a depth of 42 inches.
Particle-size control section - from 10 to 40 inches.