LOCATION RENTON WAEstablished Series
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, nonacid, mesic Mollic Fluvaquents
TYPICAL PEDON: Renton silt loam, pasture. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 6 inches; very dark grayish brown (10YR 3/2) silt loam, light brownish gray (10YR 6/2) dry; moderate medium and coarse granular structure; slightly hard, very friable, slightly sticky, slightly plastic; moderately acid (pH 6.0); abrupt wavy boundary. (6 to 8 inches thick)
C1--6 to 11 inches; dark grayish brown (2.5Y 4/2) very fine sandy loam, grayish brown (2.5Y 5/2) dry; many medium prominent brown (7.5YR 4/4) redox concentrations; massive; soft, very friable, nonsticky, nonplastic; slightly acid (pH 6.2); abrupt wavy boundary.
C2--11 to 16 inches; dark grayish brown (2.5Y 4/2) fine sandy loam, and thin lenses of fine sand, grayish brown (2.5Y 5/2) dry; many medium prominent brown (7.5YR 4/4) redox concentrations; massive; soft, very friable, nonsticky, nonplastic; slightly acid (pH 6.2); abrupt wavy boundary. (6 to 16 inches thick)
2C3--16 to 40 inches; black (10YR 2/1) sand, dark grayish brown (10YR 4/2) dry; common medium prominent strong brown (7.5YR 5/6) redox concentrations; single grained; loose; slightly acid (pH 6.4).
TYPE LOCATION: King County, Washington; 470 feet west, 1,050 feet north of east 1/4 corner, section 23, T.22N., R.4E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 52 degrees F. These soils are usually moist. The upper part of the control section contains less than 18 percent clay and more than 15 percent particles coarser than very fine sand. The lower part of the control section consists of sand or loamy sand. The control section contains less than 15 percent coarse fragments.
The Ap horizon ranges from very dark grayish brown (10YR 3/2) to dark grayish brown (10YR 4/2). It is silt loam or silty clay loam. It has moderate medium and coarse granular structure.
The C horizon is dark grayish brown (2.5Y 4/2, 10YR 4/2) depletions, with dark brown (7.5YR 4/4) redox concentrations. It is fine sandy loam to silty clay loam, with thin lenses of sand or loamy sand. This horizon is slightly acid or neutral.
The 2C horizon is black (10YR 2/1) to dark gray (10YR 4/1) with strong brown (7.5YR 5/6) concentrations, mostly in thin lenses of finer textures. It is sand or loamy sand; some pedons contain thin lenses of fine sandy loam or silt loam. The horizon is massive or single grained.
COMPETING SERIES: These are the Briscot, Cokedale, Newberg, Norma, Oridia, and Puyallup series. Briscot soils are moderately coarse textured throughout. Cokedale soils have more than 18 percent clay and significant amounts of mica, talc, and argillite above coarse substratum. Newberg and Puyallup soils have mollic epipedons. Oridia soils are medium textured. Norma soils have umbric epipedons.
GEOGRAPHIC SETTING: These soils are in river valleys with slightly undulating microrelief at elevations up to 85 feet. They formed in alluvium. Renton soils occur in a humid climate with an average January temperature of 38 degrees F.; an average July temperature of 64 degrees F.; and a mean annual temperature of about 50 degrees F. The frost free season is about 200 days. The annual precipitation ranges from 35 to 55 inches, most of which falls as rain during the winter months. Each of the summer months has at least 1 inch of rainfall. Snow is infrequent.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Briscot, Newberg, Oridia, and Puyallup soils and the Puget and Woodinville soils. Puget soils are moderately fine textured. Woodinville soils are mottled, medium to moderately fine textured soils.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; moderate permeability in the A and B horizons, and very rapid in the 2C horizon.
USE AND VEGETATION: Mostly row crops and seeded grass pasture.
DISTRIBUTION AND EXTENT: Northwestern Washington. This series is inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: King County (King County Area), Washington, 1971.
REMARKS: These soils would have been classified as Alluvial soils.