LOCATION GUMBOOT WAEstablished Series
TAXONOMIC CLASS: Fine-loamy, isotic, nonacid, mesic Aquandic Humaquepts
TYPICAL PEDON: Gumboot silt loam - woodland. (Colors are for moist soil unless otherwise noted.)
A--0 to 6 inches; black (10YR 2/1) silt loam, dark gray (10YR 4/1) dry; moderate fine and medium granular structure; soft, very friable, nonsticky and nonplastic; many fine, medium and coarse roots; very strongly acid; abrupt smooth boundary. (5 to 6 inches thick)
AB--6 to 10 inches; very dark gray (10YR 3/1) silt loam, gray (10YR 5/1) dry; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many fine, medium and coarse roots; moderately acid; clear wavy boundary. (3 to 5 inches thick)
BAg--10 to 12 inches; very dark gray (10YR 3/1) loam, light gray (10YR 6/1) dry; massive; slightly hard, very friable, slightly sticky and slightly plastic; common fine and medium roots; many very fine and fine pores; neutral; abrupt wavy boundary. (2 to 3 inches thick)
Bg--12 to 19 inches; dark gray (5Y 4/1) gravelly silty clay loam, light gray (5Y 6/1) dry; common coarse prominent reddish brown (5YR 4/4) redox concentrations; moderate medium subangular blocky structure; hard, firm, moderately sticky moderately plastic; few fine fibrous roots; common very fine tubular pores; slightly acid; clear wavy boundary. (6 to 8 inches thick)
BCg--19 to 28 inches; gray (5Y 6/1) clay loam, light gray (5Y 7/1) dry; common coarse prominent olive (5Y 5/6) redox concentrations; weak coarse prismatic separating to moderate medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine fibrous roots; common fine pores; 10 percent fine pumice grains 1-2mm; slightly acid; clear wavy boundary. (7 to 14 inches thick)
Cg--28 to 50 inches; gray (5Y 5/1) clay loam, light gray (5Y 7/1) dry; common coarse prominent olive (5Y 5/6) redox concentrations; massive; hard, firm, moderately sticky and moderately plastic; few fine fibrous roots; neutral; abrupt wavy boundary. (20 to 22 inches thick)
2C--50 to 60 inches; very gravelly and cobbly silty clay.
TYPE LOCATION: Clark County, Washington; approximately 330 feet south and 330 feet west of the east quarter corner in the northeast 1/4, northeast 1/4, southeast 1/4 of section 34, T. 5 N., R. 4 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 49 to 54 degrees F. The solum is 24 to 36 inches thick. Content of coarse fragments in the solum ranges from none to 15 percent. The 10- to 40-inch control section is dominantly clay loam with 18 to 35 percent clay and has more than 15 percent particles coarser than very fine sand.
The A and AB horizons are black or very dark gray.
The BAg and Bg horizons are dark gray or gray in hue of 2.5Y or 5Y with prominent reddish brown or yellowish red redox concentrations.
The Cg horizon is gray or light gray, and from clay loam to silty clay. Depth to very gravelly material exceeds 40 inches. Pumice grains are present throughout the 10 to 40 inch control section, but the content does not exceed 10 percent.
COMPETING SERIES: This is the Buckley series. Buckley soils are moderately deep and contain 15 to 35 percent coarse fragments.
GEOGRAPHIC SETTING: These soils are in upland basins and drainageways at elevations of 1,000 to 2,000 feet. They formed in alluvium from volcanic ash and basic igneous rocks. Gumboot soils occur in a cool, moist climate having relatively cool, dry summers and mild, wet winters. Mean annual precipitation is about 85 inches. Average January temperature is 32 degrees F., average July temperature is 65 degrees F., mean annual temperature is 52 degrees F., and the average growing season is 137 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cinebar and Kinney soils. Cinebar and Kinney soils are well drained.
DRAINAGE AND PERMEABILITY: Poorly drained; slow runoff; slow to very slow permeability.
USE AND VEGETATION: Used for woodland; drained areas are used for hay and pasture. Native vegetation is red alder, western redcedar, western hemlock, and grand fir, with an understory of vine maple, western swordfern, red huckleberry, sedge, hardhack, salmonberry, skunkcabbage, ladyfern, devilsclub, willow, trailing blackberry, and longtube twinflower.
DISTRIBUTION AND EXTENT: Southwestern Washington. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Clark County, Washington, 1971.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy.
Diagnostic horizons and features recognized in this pedon are an umbric epipedon from the surface to 10 inches and a cambic horizon from 10 to 28 inches.