LOCATION TUNNELCREEK WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic, frigid Andic Haploxerepts
TYPICAL PEDON: Tunnelcreek extremely gravelly medial sandy loam - forestland, on a 77 percent southwest-facing slope at an elevation of 2,660 feet in a western hemlock/Pacific rhododendron-salal plant association. (When described on August 12, 1993, the soil was moist throughout. Colors are for dry soil unless otherwise stated.)
Oi--0 to 1 inch; slightly decomposed needles, leaves, and twigs; abrupt smooth boundary. (1 to 2.5 inches thick)
A--1 to 8 inches; yellowish brown (10YR 5/4) extremely gravelly medial sandy loam, dark yellowish brown (10YR 3/4) moist; weak very fine and fine granular and weak very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; weakly smeary; many very fine and common fine, medium, and coarse roots; common very fine and fine irregular pores; 55 percent gravel, 10 percent cobbles; moderately acid (pH 5.8); clear smooth boundary. (4 to 7 inches thick)
Bw1--8 to 14 inches; brownish yellow (10YR 6/6) extremely gravelly sandy loam, dark yellowish brown (10YR 3/6) moist; weak very fine and fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, medium, and coarse roots; common very fine and fine irregular pores; 50 percent gravel, 15 percent cobbles; moderately acid (pH 6.0); clear wavy boundary.
Bw2--14 to 25 inches; brownish yellow (10YR 6/6) extremely cobbly sandy loam, dark yellowish brown (10YR 4/6) moist; weak very fine and fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, medium, and coarse roots; common very fine irregular pores; 35 percent gravel, 40 percent cobbles; slightly acid (pH 6.2); clear wavy boundary. (Combined thickness of the Bw horizon is 8 to 18 inches thick.)
BC--25 to 33 inches; yellowish brown (10YR 5/6) extremely cobbly sandy loam, dark yellowish brown (10YR 3/6) moist; weak very fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, medium, and coarse roots; few very fine and fine irregular pores; 40 percent gravel, 45 percent cobbles; slightly acid (pH 6.4); abrupt wavy boundary. (6 to 10 inches thick)
Cr--33 to 38 inches; weathered metavolcanic rock. (0 to 5 inches thick)
R--38 inches; hard metavolcanic rock.
TYPE LOCATION: Clallam County, Washington, about 2.25 miles east of the Gold Creek Shelter, about 2,510 feet east and 395 feet north of the southwest corner of section 3, T. 28 N., R. 3 W. (Latitude 47 degrees, 56 minutes, 24 seconds N., Longitude 123 degrees, 02 minutes, 42 seconds W.)
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 45 to 47 degrees F. These soils are usually moist but are dry in all parts of the soil moisture control section for 45 to 60 days in the 4 months following the summer solstice. Depth to bedrock is 20 to 40 inches. The particle-size control section has 60 to 90 percent rock fragments by volume and 8 to 18 percent clay. Base saturation by ammonium acetate is 70 to 90 percent throughout the profile. Acid oxalate extractable aluminum plus one-half the iron is 1 to 2 percent throughout the A and Bw horizons.
The A horizon has hue of 10YR or 7.5YR dry and moist and chroma of 3 or 4 dry and moist. It has 5 to 10 percent organic matter. Moist bulk density is 0.50 to 0.90 g/cc.
The Bw horizon has hue of 10YR or 7.5YR dry and moist, value of 5 or 6 dry and 3 or 4 moist, and chroma of 4 or 6 dry and moist. It is extremely gravelly sandy loam, extremely cobbly sandy loam, or very gravelly loam. Reaction is moderately or slightly acid. It has 1 to 5 percent organic matter. Moist bulk density is 0.80 to 1.20 g/cc.
The BC horizon has hue of 10YR dry and moist, value of 5 or 6 dry and 3 or 4 moist and chroma of 4 to 6 dry and moist. It is extremely cobbly loam, extremely gravelly sandy loam, extremely cobbly loam or extremely cobbly sandy loam.
COMPETING SERIES: These are the Juandefuca and Inkler series. Juandefuca and Inkler soils are very deep.
GEOGRAPHIC SETTING: Tunnelcreek soils are on mountains. Slopes are 60 to 90 percent. The soils formed in colluvium from marine basalt and associated volcanic rocks. Elevations are 2,100 to 3,100 feet. Average annual precipitation is 35 to 70 inches. Average annual temperature is 44 to 46 degrees F. The frost-free season is 160 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Graywolf, Halfoss, Juandefuca, Maidenpeak, Pennycreek, Slidecamp, and Station soils. Graywolf soils are on low relief dissected uplands and have an argillic horizon. Halfoss soils are on mountain slopes and have a udic moisture regime. Juandefuca and Maidenpeak soils are on mountain slopes and are very deep. Pennycreek soils are on mountain slopes and are very shallow to bedrock. Station soils are on mountain slopes and are shallow to bedrock. Slidecamp soils are on low relief dissected uplands and have an argillic horizon with less than 35 percent rock fragments.
DRAINAGE AND PERMEABILITY: Well drained; moderately rapid permeability.
USE AND VEGETATION: Timber production, wildlife habitat, recreation, and watershed. Native vegetation is Douglas-fir, western hemlock, western redcedar, Pacific rhododendron, salal, Oregon-grape, northern twinflower, and creambush oceanspray.
DISTRIBUTION AND EXTENT: Clallam and Jefferson Counties, Washington; MLRA 2. 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 - 8 to 33 inches (Bw1, Bw2, and BC horizons)
Paralithic horizon - 33 to 38 inches (Cr horizon)
Lithic contact - 38 inches
PSCS - 11 to 33 inches (Bw1, Bw2, and BC horizons)
Xeric soil moisture regime
All depths to diagnostic horizons and other features are measured from the top of the first mineral horizon.
ADDITIONAL DATA: NSSL S93WA-009-004 type location and S89WA-009-001.