LOCATION CAPLES WAEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, nonacid, mesic Fluvaquentic Endoaquepts
TYPICAL PEDON: Caples silty clay loam - pasture. (Colors are for moist soil unless otherwise noted.)
Ap1--0 to 4 inches; dark brown (10YR 3/3) silty clay loam, grayish brown (10YR 5/2) dry; moderate fine granular and subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many fine and medium and few coarse roots; many worm casts; moderately acid; abrupt smooth boundary.
Ap2--4 to 9 inches; dark brown (10YR 3/3) light silty clay loam, grayish brown (10YR 5/2) dry; many moderate distinct strong brown (7.5YR 5/8) and gray (10YR 6/1) redox concentrations and depletions, strong brown (7.5YR 5/8) and light brownish gray (10YR 6/2) dry; strong fine subangular blocky and moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine and medium and few coarse roots; few medium and coarse tubular pores; moderately acid; abrupt smooth boundary. (The A horizon has a combined thickness of 7 to 9 inches.)
Bg1--9 to 25 inches; gray (5Y 5/1) silty clay loam, gray (5Y 6/1) dry; many fine prominent yellowish red (5YR 5/6) and dark reddish brown (2.5YR 3/4) redox concentrations, strong brown (7.5YR 5/6) and dark reddish brown (2.5YR 3/4) dry; moderate coarse prismatic and moderate medium and moderate fine subangular blocky structure; hard, firm, slightly sticky and slightly plastic; many fine and medium roots; common medium tubular pores; moderately acid; clear smooth boundary.
Bg2--25 to 39 inches; grayish brown (2.5Y 5/2) silty clay loam, light brownish gray (2.5Y 6/2) dry; many medium prominent dark reddish brown (5YR 3/2), reddish brown (5YR 4/4) and strong brown (7.5YR 5/6) redox concentrations, dark reddish brown (5YR 2/2), yellowish red (5YR 5/6) and reddish yellow (5YR 6/6) dry; moderate coarse prismatic and weak thick platy structure; very hard, firm, moderately sticky and moderately plastic; common fine and medium roots; few medium, fine and coarse tubular pores; moderately acid; abrupt smooth boundary. (Combined thickness of the Bg horizon is 24 to 35 inches)
Cg1--39 to 44 inches; dark gray (5Y 4/1) silty clay loam, gray (5Y6/1) dry; few fine prominent brown (7.5YR 4/4) redox concentrations along old root channels, reddish yellow (7.5YR 6/8) dry; massive; very hard, firm, moderately sticky and moderately plastic; few fine roots; common coarse tubular pores; moderately acid; clear smooth boundary. (4 to 7 inches thick)
Cg2--44 to 77 inches; gray (N5/) silty clay loam, gray (5Y 6/1)dry; few fine prominent brown (7.5YR 4/4) redox concentrations along old root channels; strong brown (7.5YR 5/8) dry; massive; very hard, firm, very sticky and moderately plastic; few fine roots; common coarse tubular pores; moderately acid.
TYPE LOCATION: Cowlitz County, Washington; approximately 5 miles west of Longview in Willow Grove on the Gordon Enbusk farm; 500 feet north of Willow Grove Road and 170 feet west of silo; 1,500 feet west and 1,060 feet north of the southeast corner, sec. 16, T. 8 N. R.3 W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 50 to 53 degrees F. The solum is 30 to 40 inches thick. The particle-size control section averages 35 to 45 percent clay and 0 to 5 percent coarse fragments. The soils are slightly acid to strongly acid throughout.
The A horizon has value of 2 or 3 moist, value of 4 or 5 dry, and chroma of 1 to 3 moist and dry.
The Bg horizon has hue of 10YR, 2.5Y or 5Y; value of 4 or 5 moist; and chroma of 1 or 2 moist and dry. Texture is silty clay or silty clay loam.
The Cg horizon has hue of 2.5Y, 5Y, or neutral, value of 4 through 6 moist, 5 through 7 dry, and chroma of 0 through 2 moist and dry. Texture is silty clay or silty clay loam. In some pedons, the C horizon has lenses of sandy loam, loamy sand, or sand 1/2 to 3 inches thick and is sandy loam or loamy sand below depths of 40 inches.
COMPETING SERIES: These are the Godfrey, Occidental and Wunabuna soils. Godfrey soils have surface colors value of 3 to 5 moist and 5 to 7 dry. Occidental soils have a mean annual soil temperature of 54 to 59 degrees F. Wunabuna soils have buried organic material at depths of 16 to 40 inches.
GEOGRAPHIC SETTING: Caples soils are on flood plains and low terraces at elevations of less than 40 feet. Slopes are 0 to 3 percent. The soils formed in alluvium from mixed basic material. The climate is characterized by warm dry summers and cool wet winters. The average January temperature is 38 degrees F, and in July it is 65 degrees F. The average annual temperature is 52 degrees F. The average frost-free season is 165 to 195 days. The average annual precipitation is 38 to 50 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cloquato, Newberg, and Snohomish soils which have less than 35 percent clay in the particle-size control section.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow and very slow runoff; slow permeability. Depth to a seasonal high water table is at a depth of 1.5 to 2.5 feet from November to April.
USE AND VEGETATION: When drained, it is used for row crops, small grain, hay, pasture, bulbs, strawberries, and cane fruit. Native vegetation is western redcedar, red alder, black cottonwood, and bigleaf maple, with an understory of Douglas spirea, vine maple, and willow.
DISTRIBUTION AND EXTENT: Southwestern Washington. Caples soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Cowlitz County, Washington, 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are: ochric epipedon and a cambic horizon from 9 to 39 inches.