LOCATION COPALIS WAEstablished Series
TAXONOMIC CLASS: Medial, ferrihydritic, isomesic Aquic Durudands
TYPICAL PEDON: Copalis paragravelly medial silt loam - forested. (Colors are for moist soils unless otherwise stated. All textures are apparent field textures.)
Oi--0 to 0.5 inch; slightly decomposed conifer needles, branches, bark, and moss. (1/2 to 3 inches thick)
Oa--0.5 to 1 inch; highly decomposed needles, bark and moss; much mycelial growth; common coarse, medium and fine roots. (1/2 to 3 inches thick)
A1--1 to 4 inches; dark reddish brown (5YR 3/2) paragravelly medial silt loam, dark grayish brown (10YR 4/2) and reddish brown (5YR 4/3) dry; moderate fine and medium granular structure; slightly hard, very friable, nonsticky and nonplastic; weakly smeary; common coarse, medium and fine roots; 20 percent paragravels; 15 percent soft shot-like concretions; very strongly acid (pH 4.6); abrupt wavy boundary. (2 to 4 inches thick)
A2--4 to 9 inches; dark brown (7.5YR 3/2) paragravelly medial silt loam, dark brown (10YR 4/3) dry; weak fine granular and moderate very fine subangular blocky structure; slightly hard, very friable, slightly sticky and nonplastic; weakly smeary; common coarse, medium and fine roots; 20 percent paragravels; 15 percent soft shot-like concretions; very strongly acid (pH 4.8); clear wavy boundary. (4 to 7 inches thick)
Bw1--9 to 19 inches; dark reddish brown (5YR 3/3) paragravelly medial silt loam, dark brown (7.5YR 3/4) dry; moderate very fine subangular blocky and moderate fine and medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; weakly smeary; common medium and fine roots; 20 percent paragravels; 5 percent soft shot-like concretions; strongly acid (pH 5.2); gradual wavy boundary. (8 to 15 inches thick)
Bw2--19 to 26 inches; dark reddish brown (5YR 3/4) paragravelly medial silt loam, dark brown (7.5YR 3/4) dry; moderate very fine subangular blocky and moderate fine granular structure; slightly hard, friable, moderately sticky and slightly plastic and weakly smeary; common medium and fine roots; very porous; ped surfaces dark reddish brown (5YR 3/3) and reddish brown (5YR 4/4); 30 percent paragravels; 20 percent soft shot-like concretions; strongly acid (pH 5.1); abrupt wavy boundary. (4 to 10 inches thick)
2Bw3--26 to 38 inches; strong brown (7.5YR 5/6) extremely paragravelly medial silt loam, common medium distinct reddish brown (5YR 4/4) redox concentrations; light yellowish brown (10YR 6/4) dry; massive; hard, very firm, slightly sticky and slightly plastic; few fine roots; few, very fine tubular pores; 75 percent paragravels; strongly acid (pH 5.4); abrupt wavy boundary. (3 to 15 inches thick)
2Bsm--38 to 60 inches; dark brown (7.5YR 4/4) moderately cemented glacial till that crushes to extremely gravelly loamy sand, light yellowish brown (10YR 6/4) dry; massive; hard, very firm, nonsticky and nonplastic; 75 percent fine pebbles; dark reddish brown (2.5YR 2/4) 1/4 to 1/2 inch thick irregular iron cemented bands at 38 inch depth; strongly acid (pH 5.4).
TYPE LOCATION: Grays Harbor County, Washington; 30 miles north of Hoquiam; 1,440 feet north of southwest corner of section 2, T. 21 N., R. 10 W., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 51 degrees F. The difference between the mean summer and mean winter soil temperature is 5 to 9 degrees F. The soils are usually moist with a udic soil moisture regime. The solum and depth to cemented till is 20 to 40 inches. The umbric epipedon is 10 to 20 inches thick. The solum has andic soil properties throughout with moist bulk density of 0.50 to 0.90 g/cc, acid oxalate aluminum plus one-half the acid oxalate iron of 2 to 4 percent, phosphate retention is 85 to 100 percent, and 15-bar water retention is 20 to 35 percent on air-dried samples. Acid oxalate iron is 1.5 to 3.0 percent. Depth to redox concentrations is 8 to 20 inches.
The A horizon has hue of 5YR or 7.5YR moist and 10YR or 7.5YR dry, value of 3 or 4, and chroma of 2 or 3. It has weak or moderate granular to subangular blocky structure. It is very strongly or strongly acid. It has 10 to 20 percent organic matter. It has 0 to 15 percent paragravels. It has 2 to 8 cmol/kg of aluminum.
The Bw horizon has hue of 5YR or 7.5YR moist and 10YR or 7.5YR dry, value of 3 or 4, and chroma of 3 through 6. It is medial silt loam, medial silty clay loam or medial loam. This horizon has moderate or weak subangular blocky or granular structure. It is very strongly or strongly acid. It has 2 to 10 percent organic matter with less than 7 percent below 20 inches. It has 0 to 75 percent paragravels increasing with depth. It has 2 to 5 cmol/kg of aluminum.
The 2Bsm horizon is weakly or moderately cemented by iron, aluminum and manganese.
COMPETING SERIES: These are the Elwell, Oyhut and Hoko series. Elwell soils are frigid. Hoko soils are medial-skeletal. Oyhut soils have hard rock fragments.
GEOGRAPHIC SETTING: These soils are on till plains, mountain sides and mountain valleys at elevations of 30 to 800 feet. Slopes are 1 to 65 percent. They formed in alpine glacial till that include local Olympic basalt, graywacke, shales, and argillite. Copalis soils are in a humid climate with relatively cool summers and mild, wet winters. The annual precipitation is 80 to 140 inches, average January temperature is 38 degrees F., average July temperature is 58 degrees F., mean annual temperature is 50 degrees F. The frost-free period is 140 to 210 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Halbert, Nordby, Nemah, O'Brien, amd Willaby soils. Halbert and Nemah soils are poorly drained. Nordby, O'Brien, and Willaby soils lack medial properties in the control section.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow to rapid runoff; moderate permeability to the glacial till and very slow through it. A perched water table is present at 2.0 to 3.0 feet from November to April.
USE AND VEGETATION: Principal uses are timber production, wildlife habitat, watershed and recreation. The major tree species are western hemlock and Sitka spruce. Other species include Douglas-fir, western redcedar and red alder. Understory species include salal, western swordfern, vine maple, red huckleberry and Oregon grape.
DISTRIBUTION AND EXTENT: Central-western Washington; MLRA 1. Series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Reconnaissance of the western part of the Puget Sound Basin, Washington, 1910.
REMARKS: Diagnostic horizons and other features:
- Umbric epipedon - 1 to 19 inches
- Cambic horizon - 19 to 38 inches
- Andic soil properties - 1 to 38 inches
- Cemented horizon at 38 inches
- Redox concentrations at 19 inches
- All depths to diagnostic horizons and features are measured from the top of the first mineral horizon
ADDITIONAL DATA: Riverside Soil Survey Laboratory: Pedons S64Wash-14-1 and S64Wash-14-2.