LOCATION SAMISH WAEstablished Series
TAXONOMIC CLASS: Coarse-silty, magnesic, nonacid, mesic Typic Fluvaquents
TYPICAL PEDON: Samish silt loam-pasture. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures.)
Ap--0 to 8 inches; dark gray (N 4/0) silt loam, gray (N 5/0) dry; moderate medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine discontinuous pores; medium acid (pH 5.6); abrupt smooth boundary. (7 to 10 inches thick)
Cg1--8 to 23 inches; gray (N 5/0) silt loam, light gray (N 7/0) dry; common large distinct yellowish brown (10YR 5/6, 5/8) mottles; massive; hard, firm, slightly sticky and plastic; common very fine roots; common very fine discontinuous pores; few fine (1mm) relict wood and plant remains; thick (3cm) discontinuous strata with pressure faces observable when broken; soil material feels greasy; slightly acid (pH 6.2); abrupt smooth boundary. (13 to 20 inches thick)
2Cg2--23 to 26 inches; dark gray (N 4/0) very fine sandy loam, gray (N 6/0) dry; many large distinct yellowish brown (10YR 5/6, 5/8) mottles; massive; soft, friable, slightly sticky and slightly plastic; common very fine roots; common very fine discontinuous pores; fine (2- 5mm) stratification of loamy fine sand, silt loam, and silty clay loam; slightly acid (pH 6.2); clear smooth boundary. (0 to 4 inches thick)
2Cg3--26 to 36 inches; dark gray (N 4/0) very fine sandy loam, gray (N 6/0) dry; common large distinct yellowish brown (10YR 5/6), dark grayish brown (2.5Y 4/2) and olive brown (2.5Y 4/4) mottles; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine discontinuous pores; fine (2-5mm) stratification of loamy fine sand, silt loam, and silty clay loam; few fine relict wood and plant remains; slightly acid (pH 6.2); clear smooth boundary. (0 to 10 inches thick)
2Cg4--36 to 60 inches; greenish gray (5GY 5/1) silt loam, gray (N 6/0) dry; common medium prominent yellowish brown (10YR 5/6) mottles; massive; hard, firm, slightly sticky and plastic; few very fine roots; few very fine pores; slightly acid (pH 6.2).
TYPE LOCATION: Skagit County, Washington; 5 miles north of Sedro Woolley in Samish River Valley; 2,600 feet west and 200 feet south of northeast E corner, sec. 35, T. 36 N., R. 4 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is estimated to range from 48 to 52 degrees F. The upper 10 to 20 inches of the control section is greater than 40 percent by weight talc (serpentinitic family) but the weighted average is mixed mineralogy. The series control section averages less than 15 percent fine sand or coarser and between 5 and 18 percent clay. Reaction is medium acid or slightly acid throughout.
The A horizon has hue of 10YR, 2.5Y or neutral, value of 4 or 5 moist and dry, and chroma of 0 or 1 moist and dry.
The Cg horizon has hue of 2.5Y, 5Y or 5GY or neutral; value of 4 through 7 moist and dry, and chroma of 0 or 1 moist and dry. Most pedons have yellowish brown mottles.
The 2Cg horizon has colors like the Cg horizon and is stratified very fine sandy loam and silt loam with some pedons having very thin strata of loamy fine sand and silty clay loam.
COMPETING SERIES: These are the Limerick and Newalbin series. These soils lack the talc layer in the upper part of the control section.
GEOGRAPHIC SETTING: Samish soils are on flood plain terraces of narrow stream valleys at elevations of 45 to 400 feet. These soils formed in alluvium derived from talc over mixed alluvium from adjacent mountain slopes. Average annual precipitation is 35 to 60 inches. Average January temperature is about 38 degrees F and average July temperature is about 62 degrees F. Average frost-free season is 160 to 200 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cokedale, Thornton, and Wickersham soils. Cokedale soils are coarse silty over sandy or sandy- skeletal. Thornton soils have a regular decrease in organic carbon and are in a serpentinitic family. Wickersham soils are coarse loamy over sandy or sandy-skeletal.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; moderately slow permeability.
USE AND VEGETATION: Samish soils are cleared and drained and used for cropland. Major crops are hay and pasture. Native vegetation is western redcedar, western hemlock, Douglas-fir, and western swordfern.
DISTRIBUTION AND EXTENT: Northwestern Washington; the series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skagit County, Washington, about 1950.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy. Partial laboratory data are available on this soil. Soil Survey Lab. No. 79T7527. Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the surface to 8 inches and gleyed underlying material with an irregular decrease in organic carbon.