LOCATION HARKEN WAEstablished Series
TAXONOMIC CLASS: Medial over loamy, ferrihydritic over isotic, isomesic Oxyaquic Fulvudands
TYPICAL PEDON: Harken medial silt loam-forestland, on a level slope at an elevation of 870 feet in a Sitka spruce/swordfern-oxalis plant association. (Colors are for moist soil unless otherwise stated.) When described on September 27, 1994, the soil was moist throughout. (All textures are apparent field textures.)
Oi--0 to 2 inches; slightly decomposed needles, leaves, and twigs; abrupt smooth boundary. (1 to 3 inches thick)
A--2 to 5 inches; dark brown (10YR 3/3) medial silt loam, pale brown (10YR 6/3) dry; weak very fine and fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; many very fine, fine, medium, and coarse roots; many very fine and fine tubular and irregular pores; 5 percent gravel; very strongly acid (pH 4.6); clear smooth boundary. (2 to 5 inches thick)
Bw1--5 to 9 inches; dark yellowish brown (10YR 3/4) medial silt loam, light yellowish brown (10YR 6/4) dry; weak very fine and fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; common very fine, fine, medium, and coarse roots; common very fine and fine tubular and irregular pores; 5 percent gravel; very strongly acid (pH 4.8); clear wavy boundary.
Bw2--9 to 17 inches; dark brown (7.5YR 3/4) medial silt loam, light brown (7.5YR 6/4) dry; weak very fine, fine, and medium subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; common very fine, fine, medium, and coarse roots; common very fine and fine tubular and irregular pores; 5 percent grave; very strongly acid (pH 4.8); clear wavy boundary. (Combined thickness of the Bw horizon is 9 to 18 inches)
2Bw3--17 to 25 inches; dark brown (7.5YR 3/4) silty clay loam, light brown (7.5YR 6/4) dry; weak very fine, fine, and medium subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; common very fine, fine, medium, and coarse roots; common very fine and fine tubular and irregular pores; 5 percent gravel; very strongly acid (pH 5.0); clear wavy boundary.
2Bw4--25 to 36 inches; dark yellowish brown (10YR 3/6) silty clay loam, light yellowish brown (10YR 6/4) dry; weak fine, medium, and coarse subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; common very fine, fine, medium, and coarse roots; common very fine and fine tubular and irregular pores; 10 percent gravel; strongly acid (pH 5.2); clear wavy boundary.
2Bw5--36 to 45 inches; dark yellowish brown (10YR 3/6) gravelly silty clay loam, very pale brown (10YR 7/4) dry; weak very fine and fine subangular blocky structure; slightly hard, friable, moderately sticky and slightly plastic; common very fine, fine, medium, and coarse roots; common very fine and fine tubular and irregular pores; 10 percent gravel, 5 percent cobbles; strongly aid (pH 5.2); abrupt wavy boundary. (Combined thickness of the 2Bw horizon is 15 to 40 inches.)
3Bsm--45 to 53 inches; dark olive brown (2.5Y 3/3) extremely gravelly loamy sand, light olive brown (2.5Y 5/3) dry; cemented laminar cap 1 to 3 millimeters thick overlying moderately dense material; massive; hard, brittle, nonsticky and nonplastic; 45 percent gravel, 15 percent cobbles; sand grains cemented with iron to underside of rock fragments; moderately acid (pH 6.0); gradual wavy boundary. (6 to 10 inches thick)
3C--53 to 62 inches; olive brown (2.5Y 4/4) extremely gravelly loamy sand, light yellowish brown (2.5Y 6/3) dry; single grained; loose, nonsticky and nonplastic; 50 percent gravel, 25 percent cobbles; moderately acid (pH 6.0).
TYPE LOCATION: Clallam County, Washington, about 2/3 mile south of the Klahowya Forest Service Campground, about 310 feet east and 1,230 feet south of the northwest corner of Section 34, T. 30 N., R. 11 W. (Latitude 48 degrees, 03 minutes, 25 seconds N., Longitude 124 degrees, 06 minutes, 38 seconds W.)
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 50 degrees F. The difference between the mean summer and mean winter soil temperature is 5 to 9 degrees F. These soils are usually moist, and are dry 30 to 45 consecutive days in the soil moisture control section. Depth to cemented outwash is 40 to 60 inches. The upper part of the particle-size control section has andic soil properties with a cumulative thickness of 14 to 20 inches and 0 to 20 percent rock fragments by volume. The andic soil material has an estimated moist bulk density of 0.70 to 0.90 g/cc, acid-oxalate extractable aluminum plus one half of the acid-oxalate extractable iron of 2 to 4 percent, phosphate retention of 85 to 100 percent, 15-bar water retention of 15 to 25 percent for air dried samples and acid oxalate iron of 1.5 to 3.0 percent.
The A horizon has hue of 10YR or 7.5YR moist and dry and value of 3 or 4 moist and 5 or 6 dry. It has 10 to 20 percent organic matter.
The Bw horizon has hue of 10YR or 7.5YR moist and dry, value of 6 or 7 dry, and chroma of 4 or 6 moist. It is medial silt loam. Reaction is very strongly or strongly acid. It has 7 to 12 percent organic matter decreasing to less than 7 percent within 20 inches of the mineral soil surface.
The 2Bw horizon has color similar to the Bw horizons. It is silty clay loam or gravelly silty clay loam. Reaction is very strongly or strongly acid. It is assumed to have a bulk density of over 0.90 g/cubic centimeter and thus does not meet andic soil properties.
The 3Bsm horizon has value of 3 or 4 moist and 5 or 6 dry and chroma of 3 or 4 moist and dry. It is extremely gravelly loamy sand or extremely cobbly loamy sand. Reaction is moderately or slightly acid.
The 3C horizon has value of 3 or 4 moist and 5 or 6 dry and chroma of 3 or 4 moist and dry. It is extremely gravelly sand, extremely cobbly sand, or extremely gravelly loamy sand. Reaction is moderately or slightly acid.
COMPETING SERIES: This is the Tolovana series. Tolovana soils lack the cemented outwash material.
GEOGRAPHIC SETTING: Harken soils are on high stream terraces. Slopes are 2 to 10 percent. The soils formed in residuum from slackwater deposits over glacial outwash. Elevations are 500 to 1,000 feet. Average annual precipitation is 95 to 125 inches. Average annual temperature is 46 to 48 degrees F. The frost-free season is 140 to 160 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Nanich and Solduc soils. Nanich and Solduc soils are on glacial outwash terraces and have greater than 35 percent rock fragments in the particle-size control section.
DRAINAGE AND PERMEABILITY: Moderately well drained; moderate over very slow permeability. Harken soils have a perched seasonal zone of saturation between 3.0 and 5.0 feet from November through April; oxyaquic conditions.
USE AND VEGETATION: Timber production, wildlife habitat, recreation, and watershed. Native vegetation is Sitka spruce, western hemlock, western redcedar, red alder, Douglas-fir, western swordfern, Oregon oxalis, mosses, false lily-of-the-valley, and deer fern.
DISTRIBUTION AND EXTENT: Clallam County, Washington; MLRA 1. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Clallam County, Washington, 2000; Olympic National Forest.
REMARKS: Diagnostic horizons and features recognized in this pedon are the following:
Ochric epipedon
Cambic horizon - 5 to 45 inches (Bw1, Bw2, Bw3, Bw4, and Bw5 subhorizons)
Cemented pan - 45 to 53 inches (3Bsm horizon)
Andic soil properties - 2 to 17 inches (A, Bw1, and Bw2 subhorizons)
Particle size control section - 2 to 42 inches (A and Bw1 through Bw5 subhorizons); 2 to 17 inches is medial and 17 to 42 inches is loamy.
This soil would classify as Oxyaquic if such a subgroup were recognized.
All depths to diagnostic horizons and features are measured from the top of the first mineral horizon.