LOCATION LUNCHCREEK WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, mixed, isofrigid Pachic Fulvudands
TYPICAL PEDON: Lunchcreek gravelly medial silt loam-forestland, on a 63 percent northeasterly aspect at an elevation of 1,990 feet in a Pacific silver fir/swordfern-oxalis plant association. (When described on May 7, 1997, the soil was moist throughout. Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
Oi--0 to 1 inch; slightly decomposed needles, leaves, twigs, and cone fragments; abrupt smooth boundary. (1 to 3 inches thick)
Oa--1 to 7 inches; highly decomposed organic materials; many very fine and fine and common medium and coarse roots; abrupt smooth boundary. (3 to 7 inches thick)
A--7 to 11 inches; dark brown (7.5YR 3/4) gravelly medial silt loam, yellowish brown (10YR 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; weakly smeary; many very fine and common fine, medium, and coarse roots; many very fine and fine tubular and irregular pores; 20 percent gravel; extremely acid (pH 4.4); clear wavy boundary. (3 to 5 inches thick)
Bw1--11 to 20 inches; 85 percent dark yellowish brown (10YR 4/6) gravelly medial silt loam, yellow (10YR 7/6) dry and 15 percent dark brown (10YR 3/3), brown (10YR 5/3) 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; 30 percent gravel; very strongly acid (pH 4.6); clear wavy boundary.
Bw2--20 to 26 inches; dark yellowish brown (10YR 4/6) very gravelly medial loam, brownish yellow (10YR 6/6) dry; weak very fine, fine, and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; few very fine, fine, medium, and coarse roots; few very fine and fine tubular and irregular pores; 50 percent gravel, 5 percent cobbles; very strongly acid (pH 4.6); clear wavy boundary.
Bw3--26 to 34 inches; dark yellowish brown (10YR 4/6) extremely gravelly medial loam, yellow (10YR 7/6) dry; weak very fine, fine, and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; few very fine, fine, medium, and coarse roots; few very fine and fine tubular and irregular pores; 50 percent gravel, 15 percent cobbles; very strongly acid (pH 4.6); clear wavy boundary.
Bw4--34 to 51 inches; dark yellowish brown (10YR 4/6) extremely gravelly medial loam, brownish yellow (10YR 6/6) dry; weak very fine and fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; few very fine roots; few very fine and fine tubular and irregular pores; 50 percent gravel, 30 percent cobbles; very strongly acid (pH 4.8); abrupt wavy boundary. (Combined thickness of the Bw horizon is 35 to 57 inches.)
R--51 inches; hard metasedimentary rock.
TYPE LOCATION: Jefferson County, Washington, about 3 1/2 miles south-southwest of Spruce Bottom Shelter, about 105 feet east and 1,270 feet south of the northwest corner of Section 4, T. 24 N., R. 10 W. (Latitude 47 degrees, 36 minutes, 05 seconds North, Longitude 123 degrees, 57 minutes, 55 seconds West)
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 43 to 47 degrees F. The mean summer soil temperature is 47 to 50 degrees F and the mean winter soil temperature is 40 to 45 degrees F. The difference between the mean summer and winter soil temperature is 5 to 9 degrees F. These soils are usually moist and have a surplus of available water on a monthly basis throughout the year; perudic soil moisture regime. Depth to bedrock is 40 to greater than 60 inches. The particle-size control section from the mineral soil surface to 40 inches has andic soil properties throughout, and 15 to 85 percent rock fragments by volume, however the weighted average volume of rock fragments is over 35 percent. The andic soil material has an estimated moist bulk density of 0.30 to 0.70 g/cc, acid-oxalate extractable aluminum plus one half of the acid-oxalate extractable iron of 2 to 5 percent, phosphate retention of 85 to 100 percent, 15-bar water retention of 25 to 50 percent for air dried samples and acid oxalate iron of 1.0 to 2.5 percent. It has 2 to 8 cmol/kg of aluminum. The particle-size control section has 10 to 25 percent field estimated clay and 10 to 35 percent sand.
The A horizon has hue of 10YR or 7.5YR moist and dry, value of 2 through 4 moist and 4 through 6 dry, and chroma of 3 or 4 moist and dry. It has 20 to 40 percent organic matter.
The Bw horizon has hue of 10YR or 7.5YR moist and dry, value of 3 through 5 moist and 5 through 7 dry, and chroma of 3, 4, or 6 moist and dry. It is gravelly medial silt loam, very gravelly medial loam, extremely gravelly medial loam, or very gravelly medial silt loam. It has weak or moderate structure. It has 10 to 20 percent organic matter to a depth of 40 inches and decreases to 1 to 10 percent below 40 inches.
COMPETING SERIES: These are the Hookbranch, Itswoot, Snahopish and Solleks series. Hookbranch soils are 20 to 40 inches to bedrock. Snahopish and Solleks have a udic soil moisture regime. Itswoot soils formed in glacial till and have rounded rock fragments and have a udic moisture regime.
GEOGRAPHIC SETTING: Lunchcreek soils are on mountain slopes, dissected mountain slopes, and mountain headwalls. Slopes are 50 to 100 percent. The soils formed in colluvium from sedimentary and metasedimentary rocks. Elevations are 800 to 3000 feet. Average annual precipitation is 130 to 210 inches. Fog drip contributes to the effective precipitation totals. Average annual temperature is 41 to 45 degrees F. The frost-free season is 120 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hookbranch, Itswoot, Snahopish, Sockeye, and Solleks series. Hookbranch soils are on mountain slopes and headwalls and are moderately deep. Itswoot soils are on glacial valleys and have a udic soil moisture regime. Snahopish and Solleks soils are on mountain slopes and mountain headwalls and have a udic soil moisture regime. Sockeye soils are on mountain slopes and dissected mountain slopes and also have a udic soil moisture regime.
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 swordfern, Oregon oxalis, and Alaska huckleberry.
DISTRIBUTION AND EXTENT: Jefferson County, Washington; MLRA 4A. Series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Jefferson County, Washington, 2000; Olympic National Forest.
REMARKS: Diagnostic horizons and features recognized in this pedon are the following:
Folistic epipedon - 0 to 7 inches
Ochric epipedon
Cambic horizon - 11 to 51 inches (Bw1 through Bw4 horizons)
Andic soil properties - 7 to 51 inches (A, Bw1 through Bw4 horizons)
Fulvudands - Organic carbon requirement based on laboratory data from the associated Solleks, Larsencreek, Flatbottom and McKinnon series.
Mixed - Mineralogy based on laboratory data from the Sollecks series.
Lithic contact - 51 inches
PSCS - 7 to 47 inches (A, Bw1, Bw2, Bw3, and a portion of Bw4 horizons)
This soil has a perudic moisture regime.
All depths to diagnostic horizons and features are measured from the top of the first mineral horizon.