LOCATION RAUGHT             WA
Established Series
Rev. RFP/RJE/TLA
5/98

RAUGHT SERIES


The Raught series consists of very deep, well drained soils formed in colluvium weathered from basalt with an admixture of volcanic ash and loess in the upper part. Raught soils are on foothills and mountains and have slopes of 5 to 90 percent. The average annual precipitation is about 55 inches and average annual temperature is about 50 degrees F.

TAXONOMIC CLASS: Fine, parasesquic, mesic Typic Palehumults

TYPICAL PEDON: Raught silt loam on a 40 percent northwest-facing slope under a forest canopy of Douglas-fir, western hemlock and western redcedar at 600 feet elevation. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures.)

Oe--l inch to 0; partially decomposed leaf litter; abrupt smooth boundary. (l to 2 inches thick)

Al--0 to 2 inches; dark reddish brown (5YR 3/2) silt loam, dark reddish gray (5YR 4/2) dry; strong fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; NaF pH l0.5; many medium and fine roots; many medium and fine tubular pores; medium acid (pH 5.6); clear wavy boundary.

A2--2 to 7 inches; dark reddish brown (5YR 3/3) silt loam, reddish brown (5YR 5/3) dry; moderate medium and fine granular structure; hard, friable, slightly sticky and slightly plastic; weakly smeary; NaF pH l0.5; common medium and fine roots; many medium and fine tubular pores; strongly acid (pH 5.4); gradual wavy boundary. (Combined thickness of the A horizon is 6 to 11 inches)

AB--7 to l7 inches; dark reddish brown (5YR 3/3) silt loam, reddish brown (5YR 5/3) dry; moderate coarse medium and fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; weakly smeary; NaF pH l0.5; common medium and fine roots; common, medium and fine tubular pores; 5 percent pebbles; strongly acid (pH 5.4); clear smooth boundary. (0 to ll inches thick)

BA--l7 to 3l inches; dark reddish brown (5YR 3/4) silt loam, reddish brown (5YR 5/4) dry; weak coarse and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; weakly smeary; NaF pH l0.5; few coarse and medium roots; common medium and fine tubular pores; 5 percent pebbles; strongly acid (pH 5.4); clear smooth boundary. (l0 to l5 inches thick)

Bt--3l to 65 inches; dark red (2.5YR 3/6) silty clay loam, reddish brown (5YR 5/4) dry; weak very coarse and coarse subangular blocky structure parting to coarse and medium subangular blocky; hard, friable, slightly sticky and slightly plastic; weakly smeary; NaF pH l0.0; few coarse roots; few very fine tubular pores; few faint clay films on faces of peds; l0 percent pebbles; strongly acid (pH 5.4).

TYPE LOCATION: Wahkiakum County, Washington; 400 feet west, l,500 feet south of the northeast corner of sec. l8, T. 8 N., R. 4 W., l50 feet up the driveway off the county road.

RANGE IN CHARACTERISTICS: These soils are usually moist and are dry for less than 45 consecutive days in the moisture control section following summer solstice. The particle-size control section averages 5 to 20 percent rock fragments. Bulk density is less than 0.95 g/cc in the upper 7 to 14 inches.

The A and BA horizons have hue of 5YR or 7.5YR, value of 2 or 3 moist, 4 or 5 dry and chroma of 2 or 3 moist. Reaction is strongly acid to slightly acid.

The Bt horizon has hue of 2.5YR through 7.5YR, value of 3 through 5 moist and chroma of 3 through 6 moist and 3 through 6 dry. It is clay loam, silty clay loam, or silty clay. The upper 20 inches is 5 to 20 percent coarse fragments and the horizon is as much as l5 percent pebbles and 20 percent cobbles below. Reaction is very strongly acid to moderately acid.

COMPETING SERIES: This is the Canmer series in a similar family. Canmer soils have mixed mineralogy.

GEOGRAPHIC SETTING: Raught soils are on a metastable foothill and mountain slopes at elevations ranging from l00 to l,500 feet. Raught soils formed in colluvium material weathered from basalt with an admixture of volcanic ash and loess in the upper part. Slopes range from 5 to 90 percent. The climate is marine characterized by cool, wet winters and cool, dry summers. Average annual precipitation is 50 to 70 inches. The average January temperature is 37 degrees F.; the average July temperature is 6l degrees F.; and the average annual temperature is 50 degrees F. The frost-free season (32 degrees F) is l50 to 200 days. The growing season (28 degrees F) is 200 to 240 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cathlamet, and Stimson soils and the competing Germany soils. Cathlamet soils have a cambic horizon and are medial. Stimson soils are fine-silty and have an aquic moisture regime.

DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability.

USE AND VEGETATION: Raught soils are used for timber production and cropland. Grass hay and pasture are common crops. The principal native vegetation is Douglas-fir, western hemlock, red alder, bigleaf maple, and western redcedar with an understory of vine maple, salmonberry, salal, Oregongrape, western swordfern, western brackenfern, red huckleberry, and red elderberry.

DISTRIBUTION AND EXTENT: Southwestern Washington. The soils are moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Wahkiakum County, Washington, l976.

REMARKS: Diagnostic horizons and features recognized in this pedon are an umbric epipedon from the mineral surface to 17 inches and an argillic horizon from 31 to 65 inches. These soils have a base saturation (by sum of cations) of less than 30 percent to a depth of 94 inches. Characterization data are available on these soils, Laboratory number S84WA-069-003. The moisture regime is assumed to be udic bordering on xeric. These soils would be in a Vitrandic subgroup if such were provided in Palehumults.


National Cooperative Soil Survey
U.S.A.