LOCATION REAVIS OREstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Calcic Haploxerolls
TYPICAL PEDON: Reavis silt loam, cultivated, on a 1 percent slope at an elevation of 4,260 feet (Colors are for moist soil unless otherwise noted.)
Ap--0 to 6 inches; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; weak medium granular structure; hard, friable, slightly sticky and slightly plastic; many very fine and fine and few medium roots; many very fine tubular pores; slightly acid (pH 6.2); clear smooth boundary.
A--6 to 15 inches; very dark brown (10YR 2/2) silt loam, dark grayish brown (10YR 4/2) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine tubular pores; slightly acid (pH 6.2); abrupt irregular boundary (Combined thickness of the A horizon is 10 to 20 inches)
Bw1--15 to 24 inches; dark yellowish brown (10YR 3/4) silt loam, brown (10YR 5/3) dry; weak medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic, common very fine roots; many very fine tubular pores; slightly acid (pH 6.4); abrupt wavy boundary.
Bw2--24 to 34 inches; dark yellowish brown (10YR 3/4) silt loam, brown (10YR 5/3) dry; weak coarse prismatic parting to weak medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine roots; many very fine tubular pores; slightly acid (pH 6.4); clear smooth boundary. (Combined thickness of the Bw horizon is 12 to 24 inches)
2Bw3--34 to 41 inches; dark brown (7.5YR 3/4) loam, brown (7.5YR 5/3) dry; weak medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; few very fine roots; many very fine tubular pores; 5 percent gravel; neutral (pH 6.6); clear smooth boundary. (4 to 10 inches thick)
2Bk1--41 to 54 inches; pale brown (10YR 6/3) very gravelly loam, very pale brown (10YR 7/3) dry; massive; soft, friable, slightly sticky and slightly plastic; few very fine roots; few very fine pores; 40 percent gravel; common, fine and medium calcium carbonate threads throughout and coatings on underside of gravel; strongly effervescent; moderately alkaline (pH 8.0); clear smooth boundary.
2Bk2--54 to 60 inches; pale brown (10YR 6/3) very gravelly loam, very pale brown (10YR 7/3) dry; massive; soft, friable, slightly sticky and slightly plastic; few very fine pores; 55 percent gravel; few, fine and medium calcium carbonate threads throughout and coatings on underside of gravel; strongly effervescent; moderately alkaline (pH 8.0).
TYPE LOCATION: Wallowa County, Oregon; located about 3 miles east of Joseph; 1,000 feet east and 1,400 feet north of the southwest corner of section 35, T. 2 S., R. 45 E., 100 feet north of road center. (Latitude 45 degrees, 20 minutes, 29 seconds N.; and Longitude 117 degrees, 09 minutes, and 42 seconds W.)
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 44 to 47 degrees F., and the mean summer temperature is more than 59 degrees F. The soils are usually moist but are dry in the control section for 60 to 90 consecutive days during the summer months. Depth to bedrock is greater than 60 inches. Depth to the very gravelly calcic horizon is 30 to 44 inches. The mollic epipedon is 10 to 20 inches thick. The particle-size control section average 18 to 27 percent clay and more than 15 percent coarser than very fine sand, with 5 to 25 percent gravel.
The A horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 1 or 2 moist and dry. It has 0 to 10 percent gravel. It is silt loam with 18 to 27 percent clay. Reaction is slightly acid or neutral.
The Bw horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 4 or 5 dry and chroma of 3 and 4 moist and dry. It is silt loam or loam 18 to 27 percent clay and with 0 to 10 percent gravel. Reaction is slightly acid or neutral.
The 2Bw horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 4 or 5 dry and chroma of 3 or 4 moist and dry. It is silt loam or loam with 18 to 27 percent clay and 5 to 25 percent gravel. Reaction is slightly acid or neutral.
The 2Bk horizon has hue of 10YR or 7.5YR, value of 4 to 6 moist, 5 to 7 dry and chroma of 3 or 4 moist and dry. It is very gravelly silt loam or very gravelly loam with 15 to 25 percent clay. It has 35 to 55 percent gravel and 0 to 5 percent stones. It has 20 to 30 percent calcium carbonate equivalent with threads throughout and carbonate coatings on underside of gravel. Reaction is slightly alkaline or moderately alkaline.
COMPETING SERIES: These are the Araveton, Causey, Kerl, Kuvasz (T) and Picayune soils. Araveton, Causey, Kerl, and Picayune soils lack the underlying very gravelly glacial outwash materials and have a calcic horizon at depths less than 30 inches. In addition, Picayune soils have B horizons containing 20 to 50 percent limestone rock fragments and particle-size control sections with more than 27 percent clay. Kauvasz soils are 20 to 40 inches to a lithic contact (basalt).
GEOGRAPHIC SETTING: The Reavis soils are on gently undulating glacial outwash plains at elevations of 3,600 to 4,400 feet. Slopes are 0 to 3 percent. The soils formed in glaciofluvial outwash with an influence of mixed loess and minor amounts of volcanic ash in the surface horizons. The climate is characterized by cool wet winters and hot dry summers. The mean annual precipitation is 13 to 17 inches. The mean annual temperature is 42 to 45 degrees F. The frost-free period is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chesnimnus, Lostine, Minam and Redmont series. The Chesnimnus soils have argillic horizons and are on adjacent terraces. The Minam, Redmont and Lostine series lack a calcic horizon. Minam soils are on nearby alluvial fans. Redmont soils are mapped in complex with Reavis soils on the same outwash plains. Lostine soils are on adjacent low stream terraces.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: This soil is used mainly for alfalfa hay and pasture with some small grain. Idaho fescue predominates the native vegetation with small amounts of related forbs.
DISTRIBUTION AND EXTENT: Valleys of northeastern Oregon; MLRA 9. The series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Wallowa County, Oregon, 1998. The source of name is Reavis School.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Mollic epipedon - the zone from 0 to 15 inches (Ap and A horizons)
Calcic horizon - the zone from 41 to 60 inches (2Bk1 and 2Bk2 horizons) with an assumed calcium carbonate equivalent of 20 to 30 percent.
Particle-size control section - the zone from 10 to 40 inches (lower part of A horizon, the Bw1, Bw2, and most of the 2Bw3 horizon).