LOCATION CHUCKANUT WAEstablished Series
TAXONOMIC CLASS: Ashy over loamy, amorphic over isotic, mesic Typic Vitrixerands
TYPICAL PEDON: Chuckanut gravelly loam - on a 15 percent convex southeast facing slope under a coniferous canopy of Douglas-fir. (Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
O1--7 to 2 inches; undecomposed needles, twigs, and leaves.
O2--2 inches to 0; decomposed forest litter.
E--0 to 2 inches; dark brown (7.5YR 4/2) gravelly sandy loam, pinkish gray (7.5YR 7/2) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots, many very fine irregular pores; 20 percent rounded pebbles; NaF pH less than 9.0; strongly acid (pH 5.4); abrupt wavy boundary. (0 to 3 inches thick)
Bs1--2 to 9 inches; dark yellowish brown (10YR 4/6) gravelly loam, brownish yellow (10YR 6/6) dry; weak fine subangular blocky structure parting to weak medium granular; slightly hard, very friable, slightly sticky, slightly plastic and weakly smeary; common very fine roots; common medium irregular pores; 25 percent rounded pebbles and 20 percent weathered sandstone fragments; NaF pH 11.5; medium acid (pH 5.6); clear wavy boundary. (7 to 10 inches thick)
Bs2--9 to 15 inches; dark yellowish brown (10YR 4/4) gravelly loam, light yellowish brown (10YR 6/4) dry; weak fine subangular blocky structure parting to weak medium granular; slightly hard, very friable, slightly sticky, slightly plastic and weakly smeary; few coarse and common fine roots; common medium irregular pores; 25 percent rounded pebbles, 25 percent weathered sandstone fragments; NaF pH 11.5; medium acid (pH 5.8); clear wavy boundary. (5 to 9 inches thick)
BC--15 to 35 inches; olive brown (2.5Y 4/4) gravelly sandy loam, pale yellow (2.5Y 8/4) dry; weak coarse subangular blocky structure; weathered, friable, nonsticky and nonplastic; very few fine roots; few medium irregular pores; 20 percent rounded pebbles and 30 percent weathered sandstone fragments; NaF pH 10.0; medium acid (pH 5.6); gradual wavy boundary. (18 to 25 inches thick)
C--35 to 49 inches; olive brown (2.5Y 4/4) gravelly loam, pale yellow (2.5Y 7/4) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; very few very fine roots; common very fine irregular pores; 20 percent rounded pebbles and 25 percent weathered sandstone fragments; NaF pH 9.0; strongly acid (pH 5.4); abrupt smooth boundary. (0 to 20 inches thick)
2Cr--49 inches; partially weathered sandstone.
TYPE LOCATION: Skagit County, Washington; 1 mile south of Devils Lake; 2,400 feet south and 300 feet east of the northwest corner, sec. 14, T. 33 N., R. 4 E.
RANGE IN CHARACTERISTICS: These soils are usually moist, but are dry in the moisture control section for 60 to 75 consecutive days. The mean annual soil temperature ranges from 47 to 52 degrees F. Depth to a paralithic contact with sandstone is more than 40 inches. Soil reaction is medium acid or strongly acid throughout. Hard rock fragments average 15 to 25 percent and weathered sandstone fragments average 15 to 45 percent in the control section.
The E horizon has hue of 7.5YR or 10YR, value of 2 through 4 moist, 4 through 7 dry, and chroma of 2 or 3 moist and 2 through 4 dry. Some pedons have an A horizon.
The Bs horizon has hue of 7.5YR or 10YR, value of 3 through 6 moist, 5 through 7 dry, and chroma of 3 through 6 moist and dry. It is gravelly loam or gravelly sandy loam. Hard pebbles average from 15 to 30 percent weathered sandstone fragments average from 10 to 45 percent.
The C horizon has hue of 10YR or 2.5Y, value of 4 through 7 moist, 6 through dry, and chroma of 2 through 6 moist and dry. It is a gravelly loam or gravelly sandy loam. Hard pebbles average from 15 to 25 percent, weathered sandstone fragments average from 20 to 50 percent. Some pedons lack a C horizon.
COMPETING SERIES: These are the Bullards, Kickerville, Nati, Sauk, Sehome, Squalicum, and Sulsavar series and the similar Cathcart, Cathlamet, Comar, Nevat, Ponto, and Sadie soils. Bullards soils have a difference of 5 to 9 degrees F between mean summer and mean winter soil temperatures. Cathcart soils have less than 15 percent hard rock fragments in the control section and are dry for 45 to 60 days. Cathlamet, Giles, Pastik and Ponto soils have less than 15 percent hard rock fragments and lack weathered sandstone fragments in the particle-size control section. Comar soils are 15 to 80 percent weathered siltstone in the particle-size control section and are fine-loamy. Kickerville and Squalicum soils have less than 15 percent weathered rock fragments in the control section. Nati, Sehome, and Sadie soils have a paralithic contact at 20 to 40 inches. Nevat soils have a surface mantle of sand size volcanic ash 7 to 13 inches thick. Sulsavar soils lack weathered sandstone fragments in the particle-size control section.
GEOGRAPHIC SETTING: Chuckanut soils are on mountain slopes and valleys with slopes of 3 to 65 percent. Elevation ranges from 400 to 1,500 feet. The soils formed in volcanic ash and colluvium from sandstone and glacial till. Chuckanut soils have a marine climate with dry, warm summers and cool, moist winters with intermittent snow cover. The mean annual air temperature ranges from 46 to 50 degrees F, and the average annual precipitation is 35 to 45 inches. The frost-free season is 160 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Barneston, Ovall, Skipopa, Squires, and Tokul soils and the competing Cathcart soils. Barneston soils are sandy- skeletal. Ovall and Squires soils are moderately deep to a lithic contact. Skipopa soils are clayey and have an argillic horizon. Tokul soils are moderately deep to ortstein.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow or medium. Permeability is moderate.
USE AND VEGETATION: Used primarily for woodland. Native vegetation includes Douglas-fir, western hemlock, western redcedar, and red alder, with an undergrowth of salal, western brackenfern, western swordfern, Oregon-grape, red huckleberry, deer fern, princes pine, bedstraw, and Pacific trillium.
DISTRIBUTION AND EXTENT: Northwestern Washington. These soils are moderately extensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skagit County, Washington, 1980.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy. Andic soil properties at 0 to 35 inches. Diagnostic horizons and features recognized in this pedon are an albic horizon from the mineral surface to 2 inches, a spodic horizon from 2 to 15 inches, and a paralithic contact at 49 inches. The spodic horizon does not make chemical criteria for a spodic horizon but does have micro morphology. Cracked coatings and silt-sized and larger pellets.