LOCATION HOQUIAM WAEstablished Series
TAXONOMIC CLASS: Medial, ferrihydritic, mesic Typic Fulvudands
TYPICAL PEDON: Hoquiam medial silt loam, on a northwest facing 15 percent slope under coniferous forest at 380 feet elevation. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures. When described the soil was moist throughout.)
Oi--0 to 3 inches; accumulation of mosses, twigs and leaves; common fine and medium roots; abrupt smooth boundary.
A--3 to 18 inches; dark reddish brown (5YR 3/3) medial silt loam, dark brown (7.5YR 4/4) dry; strong medium granular structure; slightly hard, friable, slightly sticky, slightly plastic and weakly smeary; many fine, medium and coarse roots; many very fine tubular and interstitial pores; 10 percent rounded pebbles; very strongly acid (pH 4.6); clear wavy boundary. (10 to 20 inches thick)
Bw1--18 to 29 inches; reddish brown (5YR 4/4) medial silt loam, strong brown (7.5YR 5/6) dry; moderate medium subangular blocky structure; hard, friable, slightly sticky, slightly plastic; and weakly smeary; common fine, medium and coarse roots; many very fine tubular pores; 10 percent rounded pebbles; very strongly acid (pH 4.8); clear wavy boundary. (8 to 15 inches thick)
Bw2--29 to 46 inches; brown (7.5YR 4/4) gravelly medial silt loam, yellowish brown (10YR 5/6) dry; weak fine subangular blocky structure; hard, friable, slightly sticky, slightly plastic; and weakly smeary; few fine roots; common very fine tubular pores; 20 percent rounded pebbles; very strongly acid (pH 4.8); clear wavy boundary. (10 to 22 inches thick)
2Bw3--46 to 54 inches; brown (7.5YR 4/4) gravelly medial sandy loam, yellowish brown (10YR 5/6) dry; weak very fine subangular blocky structure; hard, friable, nonsticky and nonplastic; few fine roots; few very fine interstitial pores; 30 percent rounded and subangular pebbles; very strongly acid (pH 4.8); clear smooth boundary. (0 to 10 inches thick)
2Bsm--54 to 63 inches; brown (7.5YR 4/4) dense glacial drift that crushes to extremely gravelly loamy sand, light yellowish brown (10YR 6/4) dry; massive; compacted; very hard, very firm, nonsticky and nonplastic; 75 percent rounded and subangular pebbles with dark red (2.5YR 3/6) patchy stains; weakly cemented by iron and manganese; very strongly acid (pH 4.8).
TYPE LOCATION: Grays Habor County, Washington; 12 miles northwest of Montesano; 100 feet west of the Donovan Corkery Road, 1 mile north of its intersection with the Wishkah-Wynoochee cutoff road; SE1/4 sec. 29, T.19N., R.8W., W.M.
RANGE IN CHARACTERISTICS: Depth to cemented glacial till is 40 to 60 inches. The particle-size control section is 20 to 35 percent clay and 5 to 20 percent coarse fragments. The upper part of the control section has less than 4 percent organic carbon. Mean annual soil temperature ranges from 47 degrees to 51 degrees F. The soil is very strongly acid or strongly acid. The umbric epipedon is 10 to 20 inches thick. The moist bulk density is 0.75 to 0.90 g/cc., acid oxalate aluminum plus one-half the acid oxalate iron is 2 to 4 percent, and phosphate retention is 85 to 100. Acid oxalate iron is 1.5 to 3.0 percent. The 15-bar water on dried samples is 15 to 25 percent. The solum has 2 to 3 cmol/kg of aluminum.
The A horizon has hue of 5YR or 7.5YR moist, 7.5YR or 10YR dry, value of 4 or 5 dry and chroma of 2 or 3 moist and 2 through 4 dry. It has granular or subangular blocky structure. It has 7 to 15 percent organic matter.
The Bw horizon has hue of 5YR or 7.5YR moist, 7.5YR or 10YR dry, value of 4 or 5 moist, 5 or 6 dry and chroma of 4 through 6. It is medial silt loam, gravelly medial silt loam, medial silty clay loam or gravelly medial silty clay loam and is 5 to 35 percent coarse fragments. It has 2 to 10 percent organic matter and is less than 7 percent below 20 inches.
The 2Bw horizon has hue of 7.5YR or 10YR, value of 4 or 5 moist, 5 or 6 dry and chroma of 4 through 6. It is gravelly medial sandy loam, very gravelly medial sandy loam, gravelly medial loam or very gravelly medial loam. It is 20 to 45 percent coarse fragments.
The 2Bsm horizon has hue of 7.5YR or 10YR, value of 4 or 5 moist, 5 or 6 dry and chroma of 4 through 6. It is cemented glacial till that crushes to extremely gravelly loamy sand or very gravelly sand and is 50 to 80 percent coarse fragments.
COMPETING SERIES: These are the Arta, Astoria, Boistfort, Bunker, Copalis, Elochoman, Ilwaco, Kinney, Knappton, Lebam, Lytell, Makah, Mopang, Narel, Newskah, Oyhut, Palix, Papac, Silcox, Skamo, Vesta, Walville, Willapa, Zenker and Zyzyl series. Arta soils lack hard rock fragments and have mottles in the lower part of the control section. Astoria soils are silty clay or clay and lack hard rock fragments. Boistfort soils have 35 percent or more clay and less than 15 percent hard rock fragments. Bunder soils have short-like concretions in the upper part of the control section and have 15 to 35 percent angular basalt fragments. Copalis and Papac soils have a paralithic contact within 40 inches. Elochoman soils lack hard rock fragments. Ilwaco soils have 4 to 7 percent organic carbon in the upper two-thirds of the control section and lack hard rock fragments. Kinney soils have many shot-like concretions in the upper part of the control section and are cobbly throughout. Knappton soils have 4 to 7 percent organic carbon in the upper two-thirds of the control section. Lytel, Zenker and Zyzyl soils lack hard rock fragments and have 35 to 80 percent soft rock fragments. Makah soils have 4 to 7 percent organic carbon in the upper two-thirds of the control section and 15 to 40 percent soft rock fragments. Mopang soils have 4 to 7 percent organic carbon in the upper two-thirds of the control section. Narel and Palix soils have 4 to 7 percent organic carbon in the upper two-thirds of the control section, lack hard rock fragments and have 20 to 80 percent soft rock fragments. Newskah soils are loam with 15 to 20 percent clay and have 4 to 7 percent organic carbon in the upper two-thirds of the control section. Oyhut soils have a petroferric contact at a depth of 24 to 40 inches. Silcox soils are sandy loam or fine sandy loam and are medium acid. Skamo soils are 35 or more percent clay, lack hard rock fragments and have mottles. Vesta soils are 35 or more percent clay and have 4 to 7 percent organic carbon in the upper two-thirds of the control section. Walville soils lack hard rock fragments, have 35 to 60 percent soft breccia fragments and are medium acid. Willapa soils lack hard rock fragments, have 4 to 7 percent organic carbon in the upper two-thirds of the control section and have mottles. Zenker and Zyzyl soils lack hard rock fragments and have 35 to 80 percent soft rock fragments.
GEOGRAPHIC SETTING: Hoquiam soils are on broad ridgetops and shoulder slopes of ground moraines in uplands. Slopes range from 1 to 65 percent. These soils formed in old reworked sedimentary alluvium deposited over deeply weathered piedmont glacial drift of early Pleistocene age. Elevation ranges from 100 to 900 feet. They are in a humid marine climate with cool, wet winters and cool, dry summers. Annual precipitation ranges from 80 to 130 inches. The mean January temperature is 38 degrees F., the mean July temperature is 62 degrees F., and the mean annual temperature is 50 degrees F. The growing season (28 degrees F.) is 200 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Le Bar and the competing Copalis, Elochoman and Zenker soils. Le Bar soils lack hard rock fragments and have 0.85 or less bulk density in the control section.
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability to the cemented glacial till, very slow permeability through it; slow runoff in uncleared areas.
USE AND VEGETATION: Principal uses are timber production, watershed, wildlife habitat and recreation. Vegetation is primarily a mixed forest of Douglas-fir and western hemlock with scattered western redcedar and red alder. Understory species include western swordfern, western brackenfern, salal, red huckleberry, salmonberry, vine maple and cascara.
DISTRIBUTION AND EXTENT: Grays Harbor County, Washington; north of the Chehalis River extending to the foothills of the Olympic Mountains. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Grays Harbor County Area, Pacific and Wahkiakum Counties, Washington; 1979.
REMARKS: Diagnostic horizons and other features:
Umbric epipedon from 3 to 18 inches
Cambic horizon from 18 to 54 inches
Cemented layer from 54 to 63 inches
Andic soil properties based on data from the Mopang Series.
Mopang soils are isomesic.
All depths to diagnostic horizons and other features are measured from the top of the first mineral horizon.