LOCATION MALLORY WA+ID OREstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Pachic Argixerolls
TYPICAL PEDON: Mallory very stony silt loam- rangeland, on a 60 percent southwest slope at an elevation of 2,520 feet. (Colors are for dry soils unless otherwise noted).
A--0 to 4 inches; dark brown (10YR 3/3) very stony silt loam, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; hard, friable, sticky and plastic, many very fine and few fine roots; many very fine irregular pores; 25 percent gravel, 10 percent cobbles and 10 percent stones; neutral (pH 7.0); clear wavy boundary. (2 to 8 inches thick)
AB--4 to 9 inches; dark brown (10YR 3/3) very cobbly clay loam; dark brown (7.5YR 3/2)moist; moderate medium granular structure and moderate medium subangular blocky; hard, firm, sticky and plastic; common very fine and few fine roots; common very fine tubular and common very fine tubular pores; 30 percent gravel and 15 percent cobbles; neutral (pH 7.2); clear wavy boundary. (3 to 8 inches thick)
Bt1--9 to 20 inches; dark brown (10YR 3/3) very cobbly clay; dark brown (7.5YR 3/2) moist; moderate fine and medium subangular blocky structure; very hard, very firm, very sticky and very plastic; common very fine roots; common very fine irregular and tubular pores; many faint stress cutans on faces of peds; 30 percent gravel and 25 percent cobbles; neutral (pH 7.2); gradual wavy boundary.
Bt2--20 to 25 inches; dark brown (10YR 3/3) extremely cobbly clay, dark brown (7.5YR 3/2) moist; moderate fine and medium subangular blocky structure; very hard, firm, very sticky and very plastic; common very fine roots; common very fine irregular and tubular pores; continuous distinct stress cutans and clay films on faces of peds; 40 percent gravel, 25 percent cobbles and 5 percent stones; neutral (pH 7.2) abrupt irregular boundary. (Combined thickness of the Bt horizon is 15 to 24 inches)
2R--25 inches; basalt.
TYPE LOCATION: Asotin County, Washington; about 6 miles southwest of Anatone; 400 feet west and 1,200 feet north of southeast corner of sec. 24, T. 7 N., R. 44 E.
RANGE IN CHARACTERISTICS: Average annual soil temperature is 47 to 50 degrees F. These soils are usually moist, but are dry in all parts between 4 and 12 inches for 60 to 75 consecutive days following summer solstice. The solum thickness and depth to a lithic contact is 20 to 40 inches. The particle-size control section averages 45 to 75 percent angular basalt fragments and is 38 to 50 percent clay in the fine earth fraction. The mollic epipedon is 20 to 35 inches thick and includes all or part of the argillic horizon.
The A horizon has hue of 7.5YR or 10YR, value of 3 or 4 dry. 2 or 3 moist and chroma of 2 or 3 dry and 1 or 2 moist. The AB horizon is very cobbly clay loam or very gravelly clay loam. Reaction is neutral or slightly acid.
The Bt horizon has hue of 5 YR, 7.5YR or 10YR, value of 3 through 5 dry, 2 to 4 moist, and chroma of 2 to 4 dry or moist. It is very cobbly, extremely cobbly, very gravelly or extremely gravelly clay, silty clay, or clay loam.
COMPETING SERIES: These are the Gurdane, Tablerock and Thiessen series. Gurdane soils have a lithologic discontinuity at the Bw/2Bt horizon boundary and 10 percent or less coarse fragments in the upper part of the solum. Tablerock soils are greater than 60 inches deep to a paralithic contact and are moderately well drained. Thiessen soils are dry for 75 to 90 consecutive days
GEOGRAPHIC SETTING: Mallory soils are on canyon walls, hills and plateaus and have slopes of 2 to 90 percent. These soils formed in loess and colluvium and residuum from basalt. Elevation ranges from 1,400 to 4,300 feet. Summers are warm and dry and winters are cool and moist. The average annual precipitation ranges from 17 to 25 inches. Average annual air temperature is 45 to 50 degrees F. Frost-free season is 100 to 135 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Neconda, Gwinly, and Rockly soils. Gwinly and Rockly soils are on uplands and have a lithic contact at a depth of less than 20 inches. Neconda soils are on plateaus and have a calcic horizon and are in a fine family.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff, slow permeability.
USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Native vegetation is bluebunch wheatgrass and Idaho fescue.
DISTRIBUTION AND EXTENT: Southeastern Washington, northcentral Idaho and Northeastern Oregon. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Asotin County, Washington, 1982.
REMARKS: Diagnostic horizons and features recognized in this pedon are a mollic epipedon from the surface to 25 inches, an argillic horizon from 9 to 25 inches, and a lithic contact at 25 inches.