LOCATION SORETHUMB WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, ferrihydritic Typic Haplocryands
TYPICAL PEDON: Sorethumb very gravelly medial sandy loam-forestland, on a 73 percent southwesterly aspect at an elevation of 2,420 feet in a Pacific silver fir/Alaska huckleberry plant association. (When described on July 25, 1996, the soil was moist throughout. Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
Oi--0 to 2 inches; slightly decomposed needles, leaves, twigs, and cone fragments; abrupt smooth boundary. (1 to 6 inches thick)
Oe--2 to 8 inches; moderately decomposed organic materials; abrupt smooth boundary (0 to 7 inches thick)
A--8 to 13 inches; dark yellowish brown (10YR 3/6) very gravelly medial sandy loam, very pale brown (10YR 7/4) 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; many very fine, fine, medium, and coarse roots; many very fine and fine irregular pores; 25 percent gravel, 10 percent cobbles; very strongly acid (pH 4.6); clear smooth boundary. (2 to 5 inches thick)
Bw1--13 to 17 inches; dark yellowish brown (10YR 4/6) very gravelly medial sandy loam, very pale brown (10YR 7/4) 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; many very fine, fine, medium, and coarse roots; many very fine and fine irregular pores; 35 percent gravel, 10 percent cobbles; very strongly acid (pH 4.8); clear wavy boundary.
Bw2--17 to 22 inches; dark yellowish brown (10YR 3/6) extremely gravelly medial sandy loam, very pale brown (10YR 7/4) 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; many very fine, fine, medium, and coarse roots; many very fine and fine irregular pores; 45 percent gravel, 20 percent cobbles; strongly acid (pH 5.4); clear wavy boundary.
Bw3--22 to 29 inches; dark yellowish brown (10YR 4/6) extremely gravelly medial sandy loam, very pale brown (10YR 7/4) 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; many very fine, fine, medium, and coarse roots; common very fine and fine irregular pores; 55 percent gravel, 10 percent cobbles; moderately acid (pH 5.6); clear wavy boundary.
Bw4--29 to 37 inches; dark yellowish brown (10YR 4/6) extremely gravelly sandy loam, very pale brown (10YR 7/4) 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 irregular pores; 60 percent gravel, 15 percent cobbles; strongly acid (pH 5.4); abrupt wavy boundary. (Combined thickness of the Bw horizon is 17 to 35 inches.)
R--37 inches; hard metasedimentary rock.
TYPE LOCATION: Clallam County, Washington, about 3 1/3 miles east-northeast of Hunger Mountain about 1010 feet east and 90 feet north of the southwest corner of Section 20, T. 29 N., R. 10 W. (Latitude 47 degrees, 59 minutes, 15 seconds N., Longitude 124 degrees, 01 minutes, 30 seconds W.)
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 43 to 45 degrees F. The mean summer soil temperature is 45 to 47 degrees F. The mean winter soil temperature is 40 to 44 degrees F. The difference between the mean summer and mean winter soil temperature is 3 to 5 degrees F. These soils are usually moist, and are dry 0 to 30 consecutive days in the soil moisture control section; udic soil moisture regime. Depth to bedrock is 20 to 40 inches. The particle-size control section from the mineral soil surface to the bedrock contact has andic soil properties with 35 to 90 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 3 percent, phosphate retention of 85 to 100 percent, and 15-bar water retention of 15 to 30 percent for air dried samples. The particle-size control section has 5 to 18 percent field estimated clay and 40 to 60 percent sand. It has 1 to 2 cmol/kg of aluminum. Acid oxalate extractable iron is 1.5 to 3.0 percent.
The A horizon has value of 10YR or 7.5YR moist and dry, value of 2 through 4 moist and 4 through 7 dry, chroma of 2 through 6 moist and 3 through 6 dry. It has 10 to 20 percent organic matter.
The Bw horizon has hue of 10YR, 7.5YR, or 2.5Y moist and dry, value of 3 or 4 moist and 5 through 7 dry, and chroma of 4 or 6 moist and dry. It is extremely gravelly medial sandy loam, very gravelly medial sandy loam, very gravelly medial fine sandy loam, or very gravelly medial loam. Reaction is very strongly acid in the uppermost portion of the cambic horizon and strongly or moderately acid below. It has 1 to 10 percent organic matter with less than 7 percent below a depth 10 inches from the mineral soil surface.
COMPETING SERIES: These are the Balcher, Tylerpeak, Mueller, Sniderpeak, Fahnestock, Stonybrook, Musgrove, Blackjack and Kahkwa. Mueller, Fahnestock, Musgrove, Blackjack and Kahkwa soils are over 40 inches deep to bedrock. Balcher soils are deep to dense glacial till. Tylerpeak soils are dry for 30 to 45 consecutive days. Fahnestock and Stonybrook soils have a difference in mean summer and mean soil temperature of 6 to 9 degrees F and are over basalt.
GEOGRAPHIC SETTING: Sniderpeak soils are predominantly on mountain slopes. Slopes are 20 to 100 percent. The soils formed in colluvium and residuum from sedimentary and metasedimentary rocks. Elevations are 2700 to 3500 feet. Average annual precipitation is 95 to 120 inches. Average annual temperature is 41 to 43 degrees F. The frost-free season is 120 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Blackjack and Kahkwa soils and the Constance and Huntcreek soils. Constance soils are on mountain slopes, dissected mountain slopes, and convergent mountain headwalls and are shallow. Huntcreek soils are on glacial valleys and are moderately deep to till.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Timber production, wildlife habitat, recreation, and watershed. Native vegetation is Pacific silver fir, western hemlock, western redcedar, Pacific yew, Alaska huckleberry, red huckleberry, northern twinflower, princes pine, Oregon-grape, bunchberry dogwood, queencup beadlily, deer fern, salal, and avalanche lily.
DISTRIBUTION AND EXTENT: Olympic Mountains western slopes, Clallam County, Washington; MLRA 3. 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:
Folistic epipedon - 0 to 8 inches
Ochric epipedon
Cambic horizon - 13 to 37 inches
Andic soil properties - 8 to 37 inches
Lithic contact - 37 inches
PSCS - 8 to 37 inches
All depths to diagnostic horizons and other features are measured from the top of the first mineral horizon.