LOCATION SOREFOOT OREstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Xerertic Haplargids
TYPICAL PEDON: Sorefoot clay loam - rangeland, on a 3 percent slope at an elevation of 1,420 feet. (When described on June 10, 1998, the soil was slightly moist to a depth of 22 inches but dry below. Colors are for moist soils unless otherwise noted.)
A--0 to 2 inches; dark brown (7.5YR 3/3) clay loam, brown (7.5YR 4/3) dry; moderate fine granular structure; hard, firm, moderately sticky and very plastic; few fine and many very fine roots; few fine and common very fine irregular pores; 10 percent gravel; neutral (pH 7.2); abrupt smooth boundary. (1 to 5 inches thick)
2Bt1--2 to 10 inches; dark reddish brown (5YR 3/4) clay, reddish brown (5YR 4/4) dry; moderate medium and coarse subangular blocky structure; very hard, very firm, very sticky and very plastic; few fine and very fine roots; few very fine tubular pores; many faint clay films on ped faces; 5 percent gravel; slightly alkaline (pH 7.8); abrupt wavy boundary.
3Bt2--10 to 22 inches; dark reddish brown (2.5YR 3/4) clay, dark reddish brown (2.5YR 3/4) dry; moderate fine and medium prismatic structure; very hard, very firm, very sticky and very plastic; few very fine roots; few very fine tubular pores; many distinct clay films on ped faces and in pores; 10 percent gravel; moderately alkaline (pH 8.4); clear wavy boundary. (Combined thickness of the Bt horizons is 14 to 25 inches)
4Btk--22 to 42 inches; dark reddish brown (5YR 3/4) extremely gravelly clay, reddish brown (5YR 4/4) dry; moderate fine and medium subangular blocky structure; very hard, very firm, moderately sticky and very plastic; few very fine tubular pores; many distinct clay films on ped faces and on rock faces; carbonate coatings on the underside of rocks; 20 percent cobbles and 50 percent gravel; strongly effervescent; strongly alkaline (pH 8.7); clear wavy boundary. (0 to 25 inches thick)
4Bk--42 to 60 inches; reddish brown (5YR 4/4) very gravelly clay loam, reddish brown (5YR 5/4) dry; weak fine and medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine tubular pores; carbonates on the underside of rocks; 10 percent cobbles and 30 percent gravel; violently effervescent; strongly alkaline (pH 8.8)
TYPE LOCATION: Wheeler County, Oregon; located about 1/2 of a mile south of Camp Hancock; 1,700 feet west and 1,800 feet north of the SE corner of section 34, T. 7 S., R. 19 E. (Latitude 44 degrees, 54 minutes, and 46 seconds N. and Longitude 120 degrees, 25 minutes, and 40 seconds W.)
RANGE IN CHARACTERISTICS: These soils are dry in all parts for one-half to three-fourths of the time when the soil temperature is above 41 degrees F. The mean annual soil temperature is 50 to 54 degrees F. Depth to bedrock is greater than 60 inches. The particle size control section averages 40 to 50 percent clay and 10 to 30 percent rock fragments. The tuffaceous sediment of the John Day or Clarno Formations have hue of 5YR, 7.5YR, 10YR, 2.5Y with the hue of 5YR or 7.5YR the most common. Depth to secondary carbonates is 15 to 30 inches.
The A horizon has hue of 7.5YR or 10YR, value of 3 or 4 moist, 4 to 6 dry, and chroma of 2 or 3 moist and dry. It has 35 to 45 percent clay. It has 0 to 10 percent cobbles and 0 to 10 percent gravel. It is neutral to moderately alkaline.
The Bt horizons have hues of 2.5YR to 2.5Y, value of 2 or 3 moist, 3 or 4 dry, and chroma of 3 or 4 moist and dry. It is clay with 45 to 55 percent clay. It has 5 to 15 percent cobbles and 5 to 15 percent gravel. It is slightly or moderately alkaline.
The Btk horizon, when present, has hue of 5YR to 2.5Y, value of 3 or 4 moist, 4 or 5 dry, and chroma of 3 or 4 moist and dry. It is clay or clay loam with 35 to 45 percent clay. It has 0 to 30 percent cobbles and 10 to 50 percent gravel. It is moderately or strongly alkaline.
The Bk horizon has hue of 5YR to 2.5Y, value of 4 or 5 moist, 5 to 7 dry, and chroma of 4 to 6 moist and dry. It is clay loam with 30 to 40 percent clay. It has 0 to 10 percent cobbles and 10 to 35 percent gravel. It is moderately or strongly alkaline.
COMPETING SERIES: These are the Dryvalley and Ninekar series. Dryvalley soils lack secondary carbonates and coarse fragments. Ninekar soils are 20 to 40 inches to bedrock.
GEOGRAPHIC SETTING: Sorefoot soils are on alluvial fans and have slopes of 1 to 8 percent. They formed in clayey alluvium weathered from tuffaceous sediment. Elevation is 1,350 to 2,200 feet. The mean annual precipitation is 9 to 12 inches, and the mean annual temperature is 48 to 52 degrees F. The frost-free period is 110 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the McCoin, Simas, Sorf, and Twickenham. McCoin soils are on south slopes, loamy, and are shallow to a paralithic contact. Simas, Sorf, and Twickenham soils have an abrupt increase in clay in the surface horizons. Simas soils are north slopes and have a mollic epipedon. Sorf soils are on both north and south slopes and are moderately deep to a paralithic contact. Twickenham soils are on south slopes or rolling ridgetops.
DRAINAGE AND PERMEABILITY: Well drained; very slow permeability.
USE AND VEGETATION: These soils are used for livestock grazing and wildlife habitat. The potential native vegetation is Thurber needlegrass, bluebunch wheatgrass, basin wildrye, and sand dropseed.
DISTRIBUTION AND EXTENT: East-central Oregon, MLRA B-10. The series is of small extent.
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:
Ochric epipedon
Argillic horizon - 2 to 42 inches (2Bt1, 3Bt2, and 4Btk horizons)
Secondary carbonates - 22 to 60 inches (4Btk and 4Bk horizons)
Particle size control section - from 2 to 22 inches (2Bt1 and 3Bt2 horizons)
ADDITIONAL DATA: Partial lab data is available for this soil. Reference sample S98OR-069-001-(1-4) from Wheeler County to NSSL in Lincoln, NE.