LOCATION COKEDALE WAEstablished Series
TAXONOMIC CLASS: Coarse-silty over sandy or sandy-skeletal, mixed, superactive, acid, mesic Aquic Xerofluvents
TYPICAL PEDON: Cokedale silt loam - on a 3 percent south-facing slope under a deciduous canopy. (Colors are for moist soil unless otherwise stated)
A--0 to 4 inches; dark gray (N/4) silt loam; bluish gray (5B 6/1) dry; massive; soft, very friable, nonsticky and nonplastic; many fine roots; few very fine irregular pores; medium acid (pH 5.6); clear smooth boundary. (2 to 6 inches thick)
C1--4 to 8 inches; gray (N/5) silt loam, bluish gray (5B 6/1) dry; few coarse prominent dark reddish brown (5YR 3/4) mottles yellowish red (5YR 5/8) dry; massive, soft, very friable, slightly sticky and slightly plastic; many fine roots; few very fine tubular pores; strongly acid (pH 5.4); abrupt smooth boundary. (4 to 12 inches thick)
C2--8 to 27 inches; very dark gray (5Y 3/1) silt loam, olive gray (5Y 5/2) dry; few medium prominent strong brown (7.5YR 5/8) mottles, brownish yellow (10YR 6/8) dry; massive; soft, very friable, slightly sticky, slightly plastic; many fine roots; few very fine tubular pores; strongly acid (pH 5.4); abrupt smooth boundary. (6 to 21 inches thick)
2C3--27 to 45 inches; dark olive gray (5Y 3/2) sand, dark gray (5Y 4/1) dry; loose; many fine roots; common fine irregular pores; strongly acid (pH 5.4); abrupt smooth boundary. (10 to 32 inches thick)
2C4--45 to 60 inches; black (5Y 2/2) very channery loamy sand, gray (5Y 5/1) dry; loose; common fine irregular pores; 40 percent channers, medium acid (pH 5.8).
TYPE LOCATION: Skagit County, Washington; # miles north of Sedro Woolley; 1,100 feet north, 600 feet west of the southeast corner, sec. 6, T. 35 N., R. 5 E.
RANGE IN CHARACTERISTICS: These soils are usually moist, but are dry for 45 to 60 consecutive days following summer solstice. The upper part of the particle-size control section has from 8 to 16 percent clay and less than 15 percent fine sand and coarser material. The lower part of the particle-size control section is sand or loamy sand and has 0 to 35 percent channers. Depth to coarse-textured material ranges from 16 to 35 inches.
The A horizon has hue of 5B, 5Y, 2.5Y or is neutral; value of 3 through 5 moist, 5 through 7 dry; and chroma of 0, 1 or 2 moist and dry.
The C horizon has hue of 5B, 5GY, 5Y or is neutral; value of 3 to 5 moist, 5 or 6 dry; and chroma of 0, 1, or 2 moist and dry and is mottled.
The 2C horizon has hue of 5Y or 2.5Y; value is 2 through 5 moist, 4 through 6 dry; and chroma of 1 or 2 moist and dry. Texture is loamy sand or sand. Soil reaction is strongly acid or medium acid. Channer size rock fragments average from 0 to 35 percent above 40 inches. Below 40 inches the substratum is stratified loamy sand to very channery sand.
COMPETING SERIES: These are the Larush, Samish and Wickersham soils in other families. Larush soils have a cambric horizon and an umbric epipedon. Samish soils are in a fine-silty family. Wickersham soils are in a coarse-loamy over sandy or sandy-skeletal family and lack mottles.
GEOGRAPHIC SETTING: Cokedale soils are on floodplains. Slopes are 0 to 3 percent. Elevation ranges from 120 to 1,200 feet. The average annual precipitation ranges from 45 to 80 inches. The mean annual soil temperature ranges from 51 to 54 degrees F. The average January temperature is about 37 degrees F, average July temperature is about 65 degrees F, and the mean annual air temperature is 49 to 52 degrees F. The frost-free season is 160 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Barneston, Gilligan, and Skipopa, and the competing Samish and Wickersham soils. Gilligan soils have a cambric horizon. Skipopa soils are medial over clayey. Barneston soils are sandy-skeletal.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Runoff is slow. Permeability is moderate in the C horizon and very rapid in the 2C horizon.
USE AND VEGETATION: Used as pasture or woodland. Native vegetation consists of Douglas-fir, red alder, western redcedar, western hemlock, and bigleaf maple, with an understory of vine maple, salmonberry, western swordfern, and nettle.
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, 1953.
REMARKS: Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the surface to 4 inches and a lithologic discontinuity to sand at 27 inches.
The soil is lithic chromic from phyllite sands and silt.