LOCATION DONKEYCREEK WAEstablished Series
TAXONOMIC CLASS: Medial over sandy or sandy-skeletal, ferrihydritic over mixed, isomesic Typic Fulvudands
TYPICAL PEDON: Donkeycreek medial silt loam, forested. (Colors are for moist soil unless otherwise noted.)
Oi--0 to 1/2 inch; slightly decomposed needles, leaves, twigs, and cone fragments; abrupt smooth boundary. (0.5 to 1 inch thick)
Oe--1/2 to 1 inch; moderately decomposed organic materials; abrupt smooth boundary. (0 to 1.5 inches thick)
Oa--1 to 3 inches; highly decomposed organic materials; abrupt smooth boundary. (1 to 3 inches thick)
A--3 to 6 inches; dark brown (7.5YR 3/4) medial silt loam, brown (7.5YR 5/4) 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 and weakly smeary; many very fine, fine, medium and coarse roots; many very fine and fine tubular and irregular pores; very strongly acid (pH 4.6); clear wavy boundary. (2 to 6 inches thick)
Bw1--6 to 11 inches; dark yellowish brown (10YR 3/6) medial loam, yellowish brown (10YR 5/6) 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 and weakly smeary; common very fine and fine and few medium and coarse roots; common very fine and fine tubular and irregular pores; 5 percent pebbles; very strongly acid (pH 4.8); clear wavy boundary.
Bw2--11 to 18 inches; dark yellowish brown (10YR 3/6) medial sandy loam, brownish yellow (10YR 6/6) dry; weak very fine and fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic and weakly smeary; few very fine, fine and medium roots; few very fine and fine irregular pores; moderately acid (pH 5.6); abrupt wavy boundary. (Combined thickness of the Bw horizon is 10 to 14 inches)
2C1--18 to 30 inches; dark olive brown (2.5Y 3/3) loamy sand, grayish brown (2.5Y 5/2) dry; massive; slightly hard, friable, nonsticky and nonplastic; few very fine and fine roots; few very fine and fine irregular pores; 5 percent gravel; moderately acid (pH 5.8); abrupt wavy boundary. (8 to 13 inches thick)
3C2--30 to 37 inches; dark olive brown (2.5Y 3/3) extremely gravelly loamy sand, light olive brown (2.5Y 5/3) dry; massive; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; 70 percent gravel, 5 percent cobbles; moderately acid (pH 5.8); abrupt wavy boundary.
3C3--37 to 60 inches; dark olive brown (2.5Y 3/3) extremely gravelly loamy sand, dark grayish brown (2.5Y 4/2) dry; single grain; loose, nonsticky and nonplastic; few very fine roots; 70 percent gravel, 10 percent cobbles; moderately acid (pH 5.8).
TYPE LOCATION: Grays Harbor County, Washington; about 5 1/2 miles southeast of Neilton; 2,000 feet south and 1,000 feet west of the northeast corner of sec. 4, T. 21 N., R. 9 W.; Longitude 123 degrees, 49 minutes, 16 seconds N. and Latitude 47 degrees, 20 minutes, 22 seconds W.
RANGE IN CHARACTERISTICS: Thickness of soil material with andic soil properties and depth to glacial outwash sands and gravel ranges from 14 to 24 inches. The content of rock fragments in the upper part of the control section ranges from 0 to 10 percent. The content of rock fragments in the lower part of the control section ranges from 40 to 85 percent. The mean annual soil temperature ranges from 47 to 50 degrees F. The difference between mean summer and mean winter soil temperature is 5 to 9 degrees F. The soil is usually moist but is dry for 30 to 45 consecutive days after the summer solstice; udic moisture regime. The upper 14 to 20 inches of mineral soil material has andic soil properties. The andic soil properties are bulk density of 0.75 to 0.90 g/cc, acid oxalate aluminum plus one-half the oxalate iron of 2 to 4 percent, phosphate retention of 85 to 100 percent, acid oxalate iron is 1.5 to 3.0 percent and 15 bar water of 20 to 35 percent on air dried samples. The solum has 2 to 3 cmol/kg of aluminum.
The A horizon has hue of 7.5YR or 10YR moist and dry, value of 3 or 4 moist and 4 or 5 dry, and chroma of 2 through 4 moist and 3 or 4 dry. It has 10 to 25 percent organic matter.
The Bw horizon has hue of 10YR or 7.5YR moist and dry, value of 3 or 4 moist and 4 through 6 dry, and chroma of 4 or 6 moist and dry. It is medial loam or medial sandy loam. It is very strongly acid, strongly acid, or moderately acid. It has 5 to 15 percent organic matter.
The 2C horizon has hue of 2.5Y or 10YR moist and dry, value of 3 or 4 moist and 4 or 5 dry, and chroma of 2 or 3 moist and 3 through 4 dry. It is loamy sand, gravelly loamy sand, or very gravelly sandy loam with 2 to 10 percent clay.
The 3C horizon has hue of 2.5Y or 10YR moist and dry, value of 3 or 4 moist and 4 or 5 dry, and chroma of 2 or 3 moist and 2 through 4 dry. It is extremely gravelly loamy sand or very gravelly loamy sand with 0 to 10 percent clay.
COMPETING SERIES: This is the Wolfer series. The Wolfer soils are 24 to 36 inches to a sand and gravel 2C horizon derived from stream alluvium of igneous origin and have an umbric epipedon 12 to 20 inches thick.
GEOGRAPHIC SETTING: These soils occur at elevations of 20 to 1,000 feet on glacial outwash terraces. Slopes are 0 to 8 percent. The soils formed in glacial outwash. The mean annual precipitation of 90 to 180 inches. The average January temperature is about 38 degrees F.; the average July temperature is about 63 degrees F. and the mean annual temperature is about 47 degrees F. The frost-free season is 140 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Mopang, Nordby, Hoko, Southshore and Vesta soils. Mopang soils are deep to dense till. Hoko soils are moderately deep to cemented till and are medial-skeletal. Nordby soils are loamy-skeletal. Southshore soils are deep to cemented till and are medial-skeletal. Vesta soils are medial over clayey.
DRAINAGE AND PERMEABILITY: Well drained; low runoff; moderate or moderately rapid over rapid permeability.
USE AND VEGETATION: These soils are used for timber production. Vegetation is mainly western hemlock and Sitka spruce with an understory of Oregon oxalis western swordfern, deer fern, Alaska huckleberry, and false lily-of-the-valley.
DISTRIBUTION AND EXTENT: Western Washington; MLRA 4A. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Grays Harbor County, Washington, 2000; Olympic National Forest.
REMARKS: Diagnostic horizons and other features are:
Ochric epipedon
Cambic horizon - 6 to 18 inches
Andic soil; properties - 3 to 18 inches
Fulvudands - the upper 12 inches of the solum has over 7 percent organic matter throughout and over 10 percent as a weighted average throughout. Organic matter is less than 7 percent below about 15 inches.
All depths to diagnostic horizons and other features are measured from the top of the first mineral horizon.