LOCATION CHITWHIN WAEstablished Series
TAXONOMIC CLASS: Medial over loamy, ferrihydritic over isotic, isomesic Aquic Fulvudands
TYPICAL PEDON: Chitwhin medial silt loam, forested. (Colors are for moist soils unless otherwise noted. All textures are apparent field textures.)
Oi--0 to 1 inch; slightly decomposed needles, leaves, and twigs. (1 to 3 inches thick)
A--1 to 6 inches; very dark grayish brown (10YR 3/2) medial silt loam, grayish brown (10YR 5/2) dry; strong medium and coarse subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic, and weakly smeary; many fine and very fine roots and few medium roots throughout; common fine and medium irregular and common medium dendritic tubular pores; extremely acid (pH 4.4); gradual smooth boundary. (5 to 9 inches thick)
Bw1--6 to 11 inches; dark brown (10YR 3/3) medial silt loam, pale brown (10YR 6/3) dry; moderate coarse and very coarse subangular blocky structure; moderately hard, firm, slightly sticky, slightly plastic, and weakly smeary; common fine and very fine roots and few medium roots throughout; common fine and medium irregular pores, and common medium dendritic tubular and few very fine dendritic tubular pores; very strongly acid (pH 4.8); gradual smooth boundary. (5 to 13 inches thick)
Bw2--11 to 21 inches; dark brown (10YR 3/3) medial silt loam, pale brown (10YR 6/3) dry; strong fine and medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic and weakly smeary; common fine and very fine roots and few medium roots throughout; common fine and medium irregular pores and few fine and medium dendritic tubular pores; strongly acid (pH 5.2); clear smooth boundary. (5 to 10 inches thick)
2Bg1--21 to 30 inches; dark grayish brown (10YR 4/2) silt loam, light brownish gray (2.5Y 6/2) dry; strong fine and medium subangular blocky structure; moderately hard, firm, moderately sticky and slightly plastic; common fine and medium roots and few coarse roots throughout; common fine irregular and few very fine dendritic tubular pores; few fine faint irregular reddish yellow (5YR 6/8), moist, iron-manganese concretions with diffuse boundaries in matrix; strongly acid (pH 5.2); gradual smooth boundary. (11 to 15 inches thick)
2Bg2--30 to 46 inches; dark grayish brown (10YR 4/2) silty clay loam, light brownish gray (2.5Y 6/2) dry; moderate coarse subangular blocky structure; moderately hard, firm, moderately sticky and very plastic; few fine and medium roots throughout; few very fine irregular and few very fine dendritic tubular pores; many medium prominent irregular yellowish red (5YR 5/8), moist, masses of oxidized iron with sharp boundaries in matrix; moderately acid (pH 5.6); gradual smooth boundary. (16 to 21 inches thick)
2Bg3--46 to 61 inches; brown (10YR 4/3) silt loam, light brownish gray (2.5Y 6/2) dry; moderate coarse subangular blocky structure; moderately hard, firm, moderately sticky and very plastic; few fine and medium roots throughout; common fine irregular and few very fine dendritic tubular pores; many medium distinct irregular yellowish red (5YR 5/8), moist, masses of oxidized iron with sharp boundaries in matrix; strongly acid (pH 5.4).
TYPE LOCATION: Grays Harbor County, Washington; about 600 feet north of the Quinault River off the Quinault Indian Nation 9115 logging road; 40 feet south and 1580 feet west of the northeast corner of section 14, T.22N., R.11W.; Latitude 47 degrees, 24 minutes, 13 seconds North and Longitude 124 degrees, 2 minutes, 19 seconds, West.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 50 degrees F. The difference between mean summer and winter soil temperature is 5 to 7 degrees. The soils are usually moist and are dry for less than 45 consecutive days; udic moisture regime. The upper part of the particle-size control section has andic soil properties with phosphate retention of 85 to 100 percent, moist bulk density of 0.70 to 0.90 g/cc, acid oxalate extractable aluminum plus one-half the iron of 2 to 4 percent, and 12 to 15 percent apparent clay. The lower part of the particle-size control section lacks andic soil properties and has 18 to 30 percent apparent clay. Depth to redox depletions and concentrations is 20 to 30 inches. Depth to the contrasting loamy material is 20 to 30 inches.
The A horizon has a hue of 10YR moist and dry, value of 2 or 3 moist and 4 or 5 dry, and chroma of 2 moist and 2 or 3 dry. It has 10 to 20 percent organic matter.
The Bw horizon has hue of 10YR moist and 10YR or 2.5Y dry, value of 5 or 6 dry, and chroma of 3 or 4 moist and dry. It is very strongly acid or strongly acid. It has 5 to 15 percent organic matter.
The 2Bg horizon has a hue of 10YR moist and 2.5Y dry, value of 4 moist and 6 dry, and chroma of 2 or 3 moist and 2 dry. It is silt loam or silty clay loam with 18 to 30 percent clay. It has 1 to 7 percent organic matter.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Chitwhin soils are on low river terraces and floodplains at elevations of 0 to 290 feet. They formed in silty alluvium. The soils are in a mild marine climate and have cool, moist summers and cool, wet winters. The mean annual precipitation is 90 to 120 inches. The average January temperature is about 38 degrees F; the average July temperature is about 61 degrees F; and the mean annual temperature is about 49 degrees F. The frost free season is 180 to 220 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Queets and Hoh series. Queets soils are medial and well drained. Hoh soils are coarse-loamy with andic soil properties having thickness of 7 to 14 inches and are moderately well or well drained.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; moderate permeability. These soils are subject to rare flooding and frequent ponding.
USE AND VEGETATION: Timber production and wildlife are the principle uses. Native vegetation is red alder, western hemlock and Sitka spruce. Understory species include red huckleberry, blue leaved huckleberry, salal, salmonberry, western swordfern, deer fern, lady fern, and Oregon oxalis.
DISTRIBUTION AND EXTENT: West side of the Olympic Peninsula in western Washington; MLRA 4A. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Grays Harbor County, Washington, 2007 Quinault Indian Reservation.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon
Cambic horizon - 6 to 61 inches
Andic soil properties - 1 to 21 inches.
All depths to diagnostic horizons or other features is measured from the top of the first mineral horizon.