LOCATION CLOQUALLUM WAEstablished Series
TAXONOMIC CLASS: Fine-silty, isotic, mesic Aquandic Dystrudepts
TYPICAL PEDON: Cloquallum silt loam - pasture. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 9 inches; dark brown (10YR 3/3) silt loam, brown (10YR 5/3) dry; strong fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; 10 percent shot size concretions; many medium and fine roots; very strongly acid (pH 4.6); abrupt smooth boundary. (7 to 9 inches thick)
Bw1--9 to 22 inches; dark yellowish brown (10YR 4/4) heavy silt loam, pale brown (10YR 6/3) dry; moderate fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; about 15 percent clay; common medium and fine roots; extremely acid (pH 4.4); clear smooth boundary. (9 to 15 inches thick)
Bw2--22 to 32 inches; yellowish brown (10YR 5/4) silty clay loam, very pale brown (10YR 7/4) dry; common fine faint light gray (5Y 7/2) and strong brown (7.5YR 5/8) mottles; strong fine subangular and angular blocky structure; hard, friable, moderately sticky and moderately plastic; about 30 percent clay; common medium and fine roots; extremely acid (pH 4.2); gradual smooth boundary. (8 to 14 inches thick)
C--32 to 62 inches; light yellowish brown (10YR 6/4) silty clay loam, very pale brown (10YR 7/4) dry, common medium distinct light olive gray (5Y 6/2) and brown (7.5YR 4/4) mottles; strong fine angular blocky structure; hard, firm, moderately sticky and moderately plastic; about 32 percent clay; few fine roots; extremely acid (pH 4.0).
TYPE LOCATION: Mason County, Washington; at Forbes; in field 50 feet south and 50 feet east of New Kamilche - Forbes cut off road and Kamilche-McCleary road intersection; northwest 1/4 of section 25, T. 19 N., R. 4 W., W.M.
RANGE IN CHARACTERISTICS: The solum is 24 to 38 inches thick. Faint to strong mottles occur below depth of 24 inches. The soils are very strongly to extremely acid and acidity increases with increasing depth. The mean annual soil temperature is 48 degrees to 51 degrees F. Thin stratified layers of very fine sandy loam to silty clay are common in the profile. The control section ranges from 25 to 35 percent clay.
The A horizon has hue of 10YR or 7.5YR moist and 10YR dry, value of 3 through 5 moist, 5 or 6 dry, and chroma of 2 or 3 moist or dry. It is silt loam or silty clay loam.
The Bw horizon has hue of 10YR moist, and 10YR or 2.5Y dry, value of 4 through 6 moist, 6 or 7 dry, and chroma of 3 or 4 moist or dry. Mottles are faint to prominent. This horizon is silt loam, clay loam, or silty clay loam and has thin layers of silty clay or very fine sandy loam.
COMPETING SERIES: These are the Giles and Kitsap series. Giles soils are well drained and lack mottles in the control section. Kitsap soils are neutral to medium acid throughout.
GEOGRAPHIC SETTING: Cloquallum soils are on gently undulating to rolling uplands. Elevation ranges from 50 to 500 feet. These soils formed in silty lacustrine sediments. Mean January temperature is about 38 degrees F.; mean July temperature is about 63 degrees F. Annual precipitation ranges from 50 to 75 inches. The growing season is about 190 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Grove and Shelton soils and the competing Kitsap soils. Grove soils have a sandy-skeletal control section. Shelton soils have a duripan.
DRAINAGE AND PERMEABILITY: Moderately well drained; medium to rapid runoff; slow permeability.
USE AND VEGETATION: Used for pasture, some grain crops and timber production. Native vegetation is Douglas-fir, western redcedar, western hemlock, red alder and bigleaf maple.
DISTRIBUTION AND EXTENT: Central-western Washington; MLRA 1. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Mason County, Washington, 1953.
REMARKS: Classification only changed 03/2001 because of recent amendments to Soil Taxonomy.