LOCATION MAL WAEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, frigid Ultic Palexeralfs
TYPICAL PEDON: Mal clay loam - cut over forest. (Colors are for moist soil unless otherwise noted.)
Oi & Oa--1 inch to 0; mixture of undecomposed and decomposed forest litter, many roots covered with moss. (1/2 to 2 inches thick)
A--0 to 8 inches; dark brown (7.5YR 3/2) clay loam, brown (7.5YR 5/2) dry; weak fine granular structure; slightly hard, friable, sticky and plastic; many fine roots; about 10 percent soft pebbles; few shot- size black concretions; strongly acid (pH 5.4); clear wavy boundary. (6 to 10 inches thick)
BA--8 to 17 inches; dark brown (7.5YR 4/4) clay loam, brown (7.5YR 5/4) dry; moderate medium subangular blocky structure; hard friable, sticky and plastic; many fine roots; few shot-size black concretions; very strongly acid (pH 4.9); clear smooth boundary. (8 to 12 inches thick)
Bt1--17 to 31 inches; strong brown (7.5YR 5/6) clay, reddish yellow (7.5YR 6/6) dry; moderate medium and coarse subangular blocky structure; hard, firm, very sticky and very plastic; few fine roots; thin continuous clay film on surfaces of ped; very strongly acid (pH 4.7); gradual wavy boundary. (8 to 15 inches thick)
Bt2--31 to 51 inches; strong brown (7.5YR 5/6) clay, reddish yellow (7.5YR 6/6) dry; moderate coarse subangular blocky structure; hard, firm, very sticky and very plastic; few compressed roots; moderately thick nearly continuous clay film on surfaces of peds; very strongly acid (pH 4.8); gradual wavy boundary. (18 to 24 inches thick)
C--51 to 80 inches; strong brown (7.5YR 5/6) clay, reddish yellow (7.5YR 6/6) dry; massive; very hard, very firm, very sticky and very plastic; 10 percent partially weathered siltstone fragments; very strongly acid (pH 4.8)
TYPE LOCATION: lewis County, Washington; 11 miles southeast of Vail; 2 chains south of road and 198 feet west of section line tag; NE 1/4 SW 1/4 sec. 27, T. 15 N., R. 2 E., W.M.
RANGE IN CHARACTERISTICS: These soils are usually moist, but are dry in the moisture control section for 45 to 60 consecutive days. Depth of weathered siltstone is more than 60 inches. The particle-size control section has 0 to 15 percent soft weathered gravel-size siltstone fragments. mean annual soil temperature is 44 degrees to 46 degrees F. The soil is strongly acid or very strongly acid throughout.
The A and BA horizons have hue of 10 YR, 7.5YR or 5YR, value of 2 to 4 moist, 2 through 6 dry, and chroma of 2 to 6 moist and dry.
The Bt horizon has hue of 7.5YR or 10YR, value of 4 or 5 moist and 5 or 6 dry, and chroma of 4 to 6 moist or dry. It is heavy clay loam, heavy silty clay loam, silty clay or clay. Clay films are thin to thick and nearly continuous on faces of peds and in pores.
The C horizon is clay loam, silty clay loam, silty clay, or clay.
COMPETING SERIES: This is the boomtown series. boomtown soils are dry for more than 60 consecutive days and have 5 to 35 percent hard rock fragments in the particle-size controls section.
GEOGRAPHIC SETTING: Mal soils are on foothills and mountains at elevations of 1,500 to 2,400 feet. They formed in tuffaceous marine siltstone interbedded with basaltic sandstone with an admixture of volcanic ash. Slopes are 5 to 65 percent. mean January temperature is about 36 degrees F.; mean July temperature is about 63 degrees F.; and mean annual temperature is about 43 degrees F. Average annual precipitation is 60 to 75 inches. The growing season (28 degrees F.) is 170 to 190 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Baumgard, Jonas, and Vailton soils. Baumgard soils lack an argillic horizon and have a mesic temperature regime. Jonas and Vailton soils lack an argillic horizon.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow to rapid runoff; moderately slow permeability.
USE AND VEGETATION: Used for timber production, watershed, and wildlife habitat. Vegetation is Douglas-fir and western hemlock with an understory of vine maple, Oregon-grape, salal, western swordfern, and bitter cherry.
DISTRIBUTION AND EXTENT: Foothills of central Cascades in Thurston and Lewis Counties in Washington. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lewis County, Washington, 1979.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy.