LOCATION VAILTON WAEstablished Series
TAXONOMIC CLASS: Medial, amorphic, frigid Alic Hapludands
TYPICAL PEDON: Vailton silt loam - under a coniferous forest on a 52 percent convex slope at an elevation of 2200 feet. (The soil was moist when described. Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
0e--l-1/2 inches to 0; needles, twigs and bark chips.
Al--0 to 9 inches; dark brown (l0YR 3/3) silt loam, brown (l0YR 5/3) dry; moderate fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic and weakly smeary; common fine, medium and coarse roots; many fine irregular pores; 5 percent pebble-size soft siltstone fragments; strongly acid (pH 5.4); clear wavy boundary. (2 to ll inches thick)
A2--9 to l8 inches; dark brown (l0YR 3/3) silty clay loam, brown (l0YR 5/3) dry; moderate fine and medium subangular blocky structure; hard, firm, sticky, plastic and weakly smeary; common fine, medium and coarse roots; many fine pores; l0 percent soft pebble-size siltstone fragments; strongly acid (pH 5.4); clear wavy boundary. (5 to ll inches thick)
Bwl--l8 to 28 inches; dark yellowish brown (l0YR 4/4) silty clay loam, light yellowish brown (l0YR 6/4) dry; moderate medium subangular blocky structure; hard, firm, sticky, plastic and weakly smeary; common fine and medium and few coarse roots; many fine pores; l5 percent soft pebble-size siltstone fragments; strongly acid (pH 5.3); clear wavy boundary. (7 to l5 inches thick)
Bw2--28 to 40 inches; dark yellowish brown (l0YR 4/4) heavy silty clay loam, light yellowish brown (l0YR 6/4) dry; moderate medium subangular blocky structure; hard, firm, sticky, plastic, and weakly smeary; few fine, medium, and coarse roots; many fine pores; 40 percent soft pebble-size siltstone fragments; strongly acid (pH 5.l); clear wavy boundary. (8 to l5 inches thick)
C--40 to 45 inches; dark yellowish brown (l0YR 4/4) heavy silty clay loam, light yellowish brown (l0YR 6/4) dry; massive; hard, firm, sticky and plastic; few medium and coarse roots; many fine and very fine pores; 75 percent soft pebble-size siltstone fragments; strongly acid (pH 5.l); clear wavy boundary. (5 to l5 inches thick)
Cr--45 inches; weathered siltstone that can be cut with a spade.
TYPE LOCATION: Lewis County, Washington; sec. 26, T. l5 N., R. 2 E., W.M.
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 43 to 47 F. Depth to the paralithic contact is 40 to 60 inches. Weathered siltstone or sandstone rock fragments average l5 to 35 percent in the particle-size control section. The soil is medium acid or strongly acid throughout.
The A horizon has hue of 7.5YR or l0YR, value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist or dry. The A2 horizon is silt loam or silty clay loam.
The Bw horizon has hue of 7.5YR or l0YR, value of 3 or 4 moist, 5 through 7 dry, and chroma of 3 or 4 moist or dry. It is silty clay loam or clay loam. Weathered rock fragments range from l5 to 40 percent.
The C horizon has 60 to 90 percent weathered siltstone and/or sandstone fragments.
COMPETING SERIES: These are the Beigle, Hyas, Jonas, Lates, Moe, Murnen, Wilhoit, and Xeno series. Jonas and Wilhoit soils lack soft rock fragments and have l0 to 35 percent unweathered rock fragments in the particle-size control section. Lates soils have a lithic contact at a depth of 20 and 40 inches. Beigle and Murnen soils lack weathered rock fragments and have 15 to 35 percent basalt or andesite fragments in the particle-size control section. Moe soils have less than 15 percent soft rock fragments and 35 to 45 percent apparent clay in the particle-size control section. Xeno soils are 15 to 55 percent weathered tuff and breccia in the particle-size control section.
GEOGRAPHIC SETTING: Vailton soils are on uplands at elevations of l700 to 2800 feet. Slopes range from 5 to 90 percent. The soils formed in residuum and colluvium from siltstone, shale and interbedded sandstone with an admixture of volcanic ash. Mean annual temperature is 4l to 45 F. and mean annual precipitation is 70 to 90 inches. The growing season (28 degrees F.) is l60 to l80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Baumgard, Mal, Pheeney, Wilkeson, and the competing Jonas soils. Baumgard soils are mesic. Mal soils have an argillic horizon. Pheeney soils are medial-skeletal. Wilkeson soils have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION Used for timber production, wildlife habitat, and watershed. Vegetation is Douglas-fir, western hemlock, red alder, bigleaf maple, and western redcedar. Understory vegetation is red huckleberry, salal, western swordfern, western brackenfern, salmonberry, Oregon oxalis, Oregon-grape, deer fern, Oregon fairybells,red elderberry, Pacific trillium, violet, Pacific yew and vine maple.
DISTRIBUTION AND EXTENT: Thurston, Lewis, and Pierce Counties, Washington. Series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lewis County, Washington, l979.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy.
Diagnostic horizon and features recognized in this pedon are an umbric epipedon from the mineral surface to 18 inches and a cambic horizon from 18 to 40 inches.