LOCATION EATONCREEK WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, ferrihydritic, isofrigid Lithic Fulvudands
TYPICAL PEDON: Eatoncreek extremely gravelly medial silt loam-forestland, on a 76 percent north-northeasterly aspect at an elevation of 1,690 feet in a Pacific silver fir/western swordfern plant association. (When described on February 3, 1994, the soil was moist throughout. Colors are for moist soil unless otherwise stated.)
Oi--0 to 1 inch; slightly decomposed needles, leaves, and twigs; abrupt smooth boundary. (1 to 3 inches thick)
A--1 to 6 inches; very dark brown (10YR 2/2) extremely gravelly medial silt loam, dark yellowish brown (10YR 3/4) dry; weak very fine and fine subangular blocky and weak very fine and fine granular structure; slightly hard, friable, nonsticky and nonplastic; moderately smeary; many very fine, fine, medium, and coarse roots; many very fine and fine tubular and irregular pores; 50 percent gravel, 10 percent cobbles; strongly acid (pH 5.4); clear smooth boundary. (3 to 9 inches thick)
Bw--6 to 17 inches; very dark grayish brown (10YR 3/2) extremely gravelly medial silt loam, dark yellowish brown (10YR 3/4) dry; weak very fine, fine, and medium subangular blocky and weak very fine and fine granular structure; slightly hard, friable, nonsticky and nonplastic; moderately smeary; many very fine and common fine, medium, and coarse roots,; many very fine and fine tubular and irregular pores; 45 percent gravel, 25 percent cobbles; strongly acid (pH 5.4); abrupt wavy boundary. (7 to 11 inches thick)
R--17 inches; hard metavolcanic rock.
TYPE LOCATION: Clallam County, Washington, about 1 1/3 miles north of the quarry that is just west of Beaver Falls, about 2,110 feet west and 2,550 feet north of the southwest corner of Section 8, T. 30 N., R. 12 W. (Latitude 48 degrees, 06 minutes, 53 seconds N., Longitude 124 degrees, 16 minutes, 08 seconds W.)
RANGE IN CHARACTERISTICS: The mean annual soil temperature at the lithic contact is 43 to 47 degrees F. The mean summer soil temperature is 47 to 50 degrees F. and the mean winter is 40 to 45 degrees F. The difference between the mean winter and mean summer 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 and thickness of the umbric epipedon is 12 to 20 inches. The solum has andic soil properties with 35 to 90 percent rock fragments by volume. The andic soil material has an estimated moist bulk density of 0.30 to 0.70 g/cc, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 2 to 6 percent, phosphate retention of 85 to 100 percent, and 15-bar water retention of 30 to 60 percent for air dried samples. Acid oxalate iron is 1.5 to 3.5 percent. The solum has 2 to 8 cmol/kg aluminum.
The A horizon has value of 2 or 3 moist and 3 through 5 dry and chroma of 2 or 3 moist and 2 through 4 dry. Reaction is strongly or moderately acid. It has 20 to 40 percent organic matter.
The Bw horizon has value of 3 or 4 dry and chroma of 2 or 3 moist and 3 or 4 dry. It is extremely gravelly medial silt loam, very gravelly medial silt loam, or very gravelly medial loam. Reaction is strongly or moderately acid. It has 10 to 30 percent organic matter.
COMPETING SERIES: This is Lizardlake and similar Dimal series. Lizardlake soils have an ochric epipedon and a udic moisture regime. Dimal soils have mixed mineralogy.
GEOGRAPHIC SETTING: Eatoncreek soils are on glaciated mountain slopes. Slopes are 40 to 90 percent. The soils formed in colluvium and residuum from hard marine basalt and associated volcanic rocks. Elevations are 800 to 2,400 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 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Adwell, Kaweeta, Lizardlake, Neah, Urboden, and Zenobia soils. Adwell soils are on glaciated mountain slopes and are moderately well drained. Kaweeta and Zenobia soils are on glaciated mountain slopes and are moderately deep. Lizardlake soils are on glaciated mountain slopes and have an ochric epipedon. Neah soils are on moderate relief mountain slopes and are moderately deep. Urboden soils are on mountain headwalls and are very deep.
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, mosses, salmonberry, Oregon oxalis, deer fern, and devils club.
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:
Umbric epipedon from 1 to 17 inches
Andic soil properties - 1 to 17 inches (A and Bw horizons)
Lithic contact - 17 inches
PSCS - 1 to 17 inches (A and Bw horizons)
This soil has a perudic moisture regime.
The soil meets the Typic requirements for meq. of aluminum and pachic subgroup criteria. All depths to diagnostic horizons and features are measured from the top of the first mineral horizon.