LOCATION FIELD WAEstablished Series
TAXONOMIC CLASS: Medial over sandy or sandy-skeletal, mixed,
nonacid, mesic Aquic Xerofluvents
TYPICAL PEDON: Field silt loam - cultivated. (Colors are for moist soils unless otherwise noted)
Ap--0 to 13 inches; dark brown (10YR 4/3) silt loam, pale brown
(10YR 6/3) dry; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine roots; few very fine discontinuous vesicular pores; NaF pH of 9.4; neutral (pH 6.8); abrupt smooth boundary. (8 to 14 inches thick)
C1--13 to 21 inches; olive (5YR 5/3) silt loam, white (5Y 8/2) and light gray (5Y 7/2) dry; common medium distinct brownish yellow (10YR 6/6) mottles; massive; slightly hard; friable; slightly sticky and slightly plastic; common very fine roots; few very fine irregular pores; distinct discontinuous layer of charcoal fragments 1 inch thick at top of horizon; NaF pH of 11.5; neutral (pH 6.6); abrupt wavy boundary. (6 to 14 inches thick)
2C2--21 to 28 inches; grayish brown (2.5Y 5/2) loamy fine sand,
white (2.5Y 8/1) dry; common coarse distinct yellowish brown (10YR 5/6) mottles; massive; soft, very friable; nonsticky and nonplastic; common very fine roots; few very fine irregular pores; NaF pH of 11.0; neutral (pH 6.8); abrupt smooth boundary. (3 to 10 inches thick)
2C3--28 to 40 inches; dark gray (5Y 4/1) fine sand, light gray (5Y 7/1) dry; common medium distinct yellowish brown (10YR 5/6) mottles; single grain; loose, few very fine roots; neutral (pH 6.8); abrupt smooth boundary. (8 to 14 inches thick)
2C4--40 to 45 inches; gray (5Y 4/1) very fine sandy loam, white (5Y 8/1) dry; massive; soft, very friable, nonsticky, nonplastic; few very fine roots; contains very dark grayish brown (10YR 3/2) strata 1 cm tick; neutral (pH 6.8); abrupt smooth boundary. (2 to 8 inches thick)
2C5--45 to 60 inches; dark gray (5Y 4/1) fine sand, white (2.5Y 8/1) dry; single grain; loose; neutral (pH 6.8).
TYPE LOCATION: Skagit County, Washington; 1-1/2 miles southwest of Sedro Wooley; 800 feet south and 1,450 feet west of the northeast corner sec. 34, T. 35 N., R. 4 E.
RANGE IN CHARACTERISTICS: These soils re usually moist, but are dry in the moisture control section for 45 to 60 consecutive days following summer solstice. The mean annual soil temperature is estimated to range from 48 to 52 degrees F. Thickness of the volcanic ash influence is 14 to 30 inches. Reaction ranges from medium to moderately acid through neutral. Depth to the apparent water table is 24 to 60 inches during late winter and early spring.
The Ap horizon has hue of 10YR or 2.5Y, values of 3 or 4 moist, 6 or 7 dry, and chroma of 2 or 3.
The C1 horizon has hue of 2.5Y or 5Y, value of 4 or 5 moist, 6 through 8 dry, and chroma of 3 or 4 moist, 2 or 3 dry. Textures are silt loam or very fine sandy loam.
The 2C horizon has hue of 2.5Y or 5Y, value of 4 or 5 moist, 6 through 8 dry, and chroma of 0, 1 or 2 moist or dry. Textures are stratified sand, fine sand, loamy fine sand,and very fine sandy loam, and average sandy above 40 inches.
COMPETING SERIES: This is the Cokedale series in another family. Cokedale soils are coarse-silty in the upper part of the control section.
GEOGRAPHIC SETTING: Field soils are on bottoms and flood plains at elevations of 10 to 50 feet. They formed in mixed recent alluvium with an admixture of volcanic ash in the upper art. Slopes are 0 to 3 percent. Average annual precipitation is 30 to 45 inches. mean January temperature is about 37 degrees F, mean July temperature is about 63 degrees F. mean annual temperature is about 50 degrees F. The frost- free season is 170 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the Mt. Vernon soil. The Mt. Vernon soils are medial over loamy.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff, moderate permeability. These soils are subject to occasional flooding unless protected.
USE AND VEGETATION: Field soils are used for cropland. native vegetation is western redcedar and Douglas-fir, with an understory of western swordfern, ladyfern, geranium, western brackenfern, trailing blackberry, longtube twinflower, Pacific oceanspray, and red huckleberry.
DISTRIBUTION AND EXTENT: Northwestern Washington. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skagit County, Washington, 1981.
REMARKS: Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the surface to 13 inches and a particle-size control section from 10 to 40 inches that has an irregular decrease in organic carbon and an abrupt textural change to sandy material at 21 inches.