LOCATION LAUREN WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, mixed, mesic Pachic Melanoxerands
TYPICAL PEDON: Lauren gravelly loam - pasture. (All colors are for moist soil unless otherwise noted.)
Ap--0 to 6 inches; very dark brown (10YR 2/2) gravelly loam, dark grayish brown (10YR 4/2) dry; moderate fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; many fine fibrous roots; 20 percent pebbles; slightly acid (pH 6.2); abrupt smooth boundary. (6 to 10 inches thick)
A--6 to 20 inches; very dark brown (10YR 2/2) very gravelly loam, dark grayish brown (10YR 4/2) dry; moderate fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; abundant fine fibrous roots; many fine and medium pores; 45 percent pebbles; slightly acid (pH 6.4); gradual wavy boundary. (8 to 15 inches thick)
AB--20 to 33 inches; dark brown (10YR 3/3) very gravelly loam, brown (10YR 4/3) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; plentiful fine fibrous roots; many very fine and common medium pores; 50 percent pebbles; slightly acid (pH 6.5); clear wavy boundary. (10 to 15 inches thick)
Bw--33 to 44 inches; dark brown (7.5YR 3/2) very gravelly coarse sandy loam, brown (10YR 5/3) dry; massive; slightly hard, very friable, nonsticky, nonplastic; few fine fibrous roots; many very fine and medium pores; 55 percent pebbles; neutral (pH 6.7); clear wavy boundary. (5 to 14 inches thick)
2C--44 to 52+ inches; dark brown (10YR 3/3) very gravelly loamy coarse sand, pale brown (10YR 6/3) dry; single grain; loose, nonsticky, nonplastic; 55 percent pebbles; neutral (pH 6.8).
TYPE LOCATION: Clark County, Washington. Eight miles east of Vancouver, Washington, at a point 600 feet north of SE 15th St., and 250 feet east of 164th Avenue, in southeast 1/4 southeast 1/4 southwest 1/4, sec. 36, T. 2 N., R. 2 E.
RANGE IN CHARACTERISTICS: These soils are usually moist but are dry in the moisture control section for 60 to 75 consecutive days following summer solstice. The mean annual temperature is 52 to 54 degrees F. The particle-size control section averages 35 to 55 percent rock fragments mostly pebbles less than 1 inch in diameter and the fine earth fraction averages 5 to 15 percent clay.
The A horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry. It is moderately acid or slightly acid. Below 10 inches, the texture is gravelly loam or very gravelly loam.
The AB horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry and chroma of 2 or 3 moist and dry. Texture is very gravelly loam or gravelly loam. Coarse fragments range from 25 to 60 percent. Reaction is moderately acid or slightly acid.
The Bw horizon has hue of 10YR or 7.5YR, and chroma of 2 or 3 moist and dry. Texture is very gravelly loam, very gravelly sandy loam, or very gravelly coarse sandy loam. Coarse fragments range from 40 to 60 percent. Reaction is moderately acid or slightly acid.
The C horizon has hue of 10YR or 7.5YR, value of 3 to 5 moist, 4 to 6 dry, and chroma of 2 to 4 moist and dry. Texture is very gravelly loamy coarse sand or very gravelly coarse sand. Coarse fragments range from 40 to 60 percent. Reaction is slightly acid or neutral.
COMPETING SERIES: These are the Emily, Frantz, Oland, and Woolstalf series. Emily soils are 25 to 35 percent clay in the Bw horizon. Frantz soils are 20 to 40 inches deep to a lithic contact. Oland soils are 18 to 24 percent clay in the particle-size control section and have a mean annual temperature of 47 to 51 degrees F. Woolstalf soils have a mean annual soil temperature of about 55 degrees F, and are dry more than 90 consecutive days.
GEOGRAPHIC SETTING: Lauren soils formed in old alluvium and loess containing volcanic ash on terraces and terrace escarpments at elevations of 150 to 300 feet. The climate is humid with warm, dry summers and mild, wet winters. The average annual precipitation is 40 to 50 inches. The mean January temperature is about 37 degrees F. The mean July temperature is about 64 degrees F, and the mean annual temperature is about 50 degrees F. The growing season (28 degrees F) is 200 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hillsboro, Sifton, and Wind River series. Hillsboro soils are fine-silty and have an argillic horizon. Sifton soils have an umbric epipedon. Wind River soils are coarse-loamy.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability in the upper part of the solum and rapid permeability in the underlying material.
USE AND VEGETATION: Most of this soil series is cleared of trees and used for cropland and urban development. Some is used for pasture and some for woodland. Common crops are hay, oats, barley, strawberries, potatoes, and dry beans. Native vegetation is Douglas-fir, western redcedar, grand fir, bigleaf maple, and red alder with an understory of vine maple, salal, Pacific dogwood, trailing blackberry, Oregon-grape, western brackenfern, and western swordfern.
DISTRIBUTION AND EXTENT: Southwestern Washington. Series is of small extent - about 13,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Clark County, Washington, 1911.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy.
Diagnostic horizons and features recognized in this pedon are: a.mollic epipedon from the surface to 33 inches; and a cambic horizon from 33 to 44 inches. The organic carbon is assumed to be less than 0.6 percent below 33 inches. Base saturation (by sum of the cations) is assumed to be less than 75 percent throughout the solum.