LOCATION ZENOBIA WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, ferrihydritic, isofrigid Pachic Fulvudands
TYPICAL PEDON: Zenobia 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/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 4 inches thick)
A--1 to 5 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 6 inches thick)
Bw1--5 to 20 inches; very dark grayish brown (10YR 3/2) 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; common very fine, fine, medium, and coarse roots; common very fine and fine tubular and irregular pores; 40 percent gravel, 25 percent cobbles; strongly acid (pH 5.4); clear wavy boundary.
Bw2--20 to 35 inches; very dark grayish brown (10YR 3/2) extremely medial cobbly 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; common very fine, fine, medium, and coarse roots; common very fine and fine tubular and irregular pores; 35 percent gravel, 40 percent cobbles; moderately acid (pH 5.6); clear wavy boundary. (Combined thickness of the Bw horizon is 17 to 34 inches thick.)
R--35 inches; volcanic rock.
TYPE LOCATION: Clallam County, Washington, about 1 1/3 miles north of the quarry that is just west of Beaver Falls, about 2,550 feet north and 2,110 feet west 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 is 43 to 47 degrees F. The difference between the mean summer and mean winter soil temperature is 5 to 9 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. These soils are usually moist and have a surplus of available water on a monthly basis throughout the year (perudic). Depth to bedrock and thickness of the umbric epipedon is 20 to 40 inches. The particle-size control section from the mineral soil surface to bedrock contact has andic soil properties with a weighted average of 60 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 4 percent, phosphate retention of 85 to 100 percent, and 15-bar water retention of 35 to 50 percent for air dried samples. Acid oxalate iron is 2.0 to 3.5 percent. It has 20 to 40 percent organic matter decreasing with depth. It has 2 to 8 cmol/kg of aluminum.
The A horizon has hue of 10YR or 7.5YR moist and value of 2 or 3 moist.
The Bw horizon has hue of 10YR or 7.5YR moist and chroma of 2 or 3 moist. It is extremely gravelly medial silt loam, extremely cobbly medial silt loam, or extremely gravelly medial loam. Reaction is strongly or moderately acid.
COMPETING SERIES: These are the Elklake, Fawceter, Flatbottom, Killam, McKinnon, and Urboden series. Urboden soils are very deep. McKinnon soils have a udic moisture regime and are deep or very deep. Elklake soils have an umbric epipedon 10 to 20 inches thick. Killam soils are dry for 0 to 30 consecutive days. Flatbottom soils are dry 0 to 30 consecutive days and have an umbric epipedon 10 to 20 inches thick. Fawceter soils are dry for 0 to 30 consecutive days and are deep.
GEOGRAPHIC SETTING: Zenobia soils are on glaciated mountain slopes. Slopes are 15 to 90 percent. The soils formed in colluvium and residuum from 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, Eatoncreek, Kaweeta, Lizardlake, Neah, Hyas, and Urboden soils. Adwell and Hyas soils are on moderate relief mountain slopes, glaciated mountain slopes, and ground moraines and are moderately well drained. Eatoncreek, Lizardlake, and Kaweeta soils are on glaciated mountain slopes and are shallow, and have an ochric epipedon, respectively. Neah soils are on moderate relief mountain slopes and are medial. 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, deer fern, salmonberry, Oregon oxalis, Alaska huckleberry, devil's club, and threeleaf foamflower.
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:
An umbric epipedon from 1 to 35 inches with depth, thickness, and organic carbon requirements of a melanic epipedon (A, Bw1, and Bw2 subhorizons)
Andic soil properties - 1 to 35 inches (A, Bw1, and Bw2 subhorizons) based on laboratory data from the Murhut series.
Lithic contact - 35 inches
PSCS - 1 to 35 inches (A, Bw1, and Bw2 subhorizons)
This soil has a perudic moisture regime
All depths to diagnostic horizons and features are measured from the top of the first mineral horizon.