LOCATION LACAMAS WAEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Typic Glossaqualfs
TYPICAL PEDON: Lacamas silt loam, pasture. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 7 inches; very dark grayish brown (10YR 3/2) silt loam, light brownish gray (10YR 6/2) dry; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; very porous; very strongly acid (pH 4.7); clear smooth boundary. (4 to 8 inches thick)
E1--7 to 15 inches; dark grayish brown (10YR 4/2) silt loam, light brownish gray (10YR 6/2) dry; few fine distinct yellowish red (5YR 4/6) mottles; moderate fine subangular blocky structure; slightly hard friable, slightly sticky and slightly plastic; common very fine and fine roots; many fine tubular pores; very strongly acid (pH 5.0); abrupt smooth boundary.
E2--15 to 17 inches; grayish brown (10YR 5/2) silt loam, white (10YR 8/2) dry; common medium distinct yellowish red (5YR 5/8) mottles; massive; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many fine tubular pores; very strongly acid (pH 5.0); abrupt irregular boundary. (Combined thickness of the E horizon is 5 to 16 inches)
B/E--17 to 19 inches; (B part) olive gray (5Y 5/2) silty clay, light olive gray (5Y 6/2) dry; few fine prominent yellowish red (5YR 5/8) and few fine distinct olive brown (2.5Y 4/4) mottles; strong medium prismatic structure; extremely hard, very firm, very sticky and very plastic; common fine tubular pores; thick continuous clay films on horizontal faces of prisms and lining pores; occupies about 65 percent of horizon; (E part) 2 to 10 mm thick coatings of grayish brown (10YR5/2) silt loam on vertical faces of prisms, white (10YR 8/1) dry; occupies about 35 percent of horizon; slightly hard, friable, slightly sticky and slightly plastic; common roots; many very fine and fine tubular pores; very strongly acid (pH 4.8); clear wavy boundary. (1 to 6 inches thick)
Btg1--19 to 27 inches; olive gray (5Y 5/2) silty clay, light olive gray (5Y 6/2) dry; few fine distinct yellowish red (5YR 5/8) and few fine faint olive brown (2.5Y 4/4) mottles; strong coarse and fine prismatic structure; extremely hard, very firm, very sticky and very plastic; few fine roots only on prism surfaces; common fine and very fine tubular pores; white silt loam coatings 1 to 3 mm thick on some peds; common moderately thick clay films on faces of peds and lining pores; very strongly acid (pH 5.0); gradual wavy boundary. (6 to 10 inches thick)
Btg2--27 to 36 inches; olive gray (5Y 5/2) silty clay, light olive gray (5Y 6/2) dry; few fine distinct yellowish red (5YR 5/8) and few fine faint olive brown (2.5Y 4/4) mottles; strong very coarse and fine prismatic structure; extremely hard, very firm, very sticky and very plastic; common very fine tubular pores; common moderately thick clay films on faces of peds and lining in pores; white silt loam coatings on some peds; slightly acid (pH 6.2); gradual wavy boundary. (8 to 12 inches thick)
Btg3--36 to 75 inches; olive gray (5Y 5/2) clay, light olive gray (5Y 6/2) dry; few fine distinct yellowish red (5YR 5/8) mottles; strong coarse prismatic structure; extremely hard, very firm, very sticky and very plastic; common very fine tubular pores; common moderately thick clay films on faces of peds and lining pores; slightly acid (pH 6.4); gradual wavy boundary. (24 to 40 inches thick)
C--75 to 80 inches; olive gray (5Y 6/2) gravelly clay, common medium distinct yellowish red (5YR 5/8) mottles; massive; extremely hard, very firm, slightly sticky and very plastic; common very fine tubular pores.
TYPE LOCATION: Lewis County, Washington; about 2.5 miles southwest of Ethel, 25 feet west of north-south fence, 25 feet north of highway ditch 130 feet north and 2,240 feet west of the southeast corner of section 15, T.12N., R.1W.
RANGE IN CHARACTERISTICS: The solum is 45 to more than 60 inches thick. Average annual soil temperature ranges from 47 degrees to 53 degrees F. The particle-size control section is 45 to 60 percent clay. Rock fragments are less than 2 percent. Up to 10 percent iron-manganese concretions occur in the A horizon of some pedons.
The A horizon has value of 2 or 3 moist, 4 through 7 dry, and chroma of 1 or 2 moist or dry. It is silt loam or silty clay loam and has moderate granular or subangular blocky structure. It is extremely acid to strongly acid.
The E horizon has value of 4 or 5 moist, 6 through 8 dry, and chroma of 1 or 2 moist or dry and is mottled dark brown to yellowish red. It is silt loam or silty clay loam. This horizon is 6 to 16 inches thick and has moderate or subangular blocky structure. The E portion of the B/E horizon occupies 20 to 45 percent of the volume. It is extremely acid to strongly acid.
The Btg horizon has hue of 5Y to 10YR, value of 5 or 6 moist, 6 through 8 dry, and chroma of 0 through 2 moist or dry and is mottled olive brown, dark brown, or yellowish red. It is silty clay or clay and is modified with rock fragments below a depth of 48 inches in some pedons. This horizon has moderate or strong prismatic structure that parts to moderate or strong subangular or angular blocky. It is extremely acid to moderately acid in the upper part and slightly acid to strongly acid in the lower part.
The C horizon, when present, has the same matrix and mottle colors as the Btg horizon. It is clay, clay loam, or silty clay and is not gravelly in some pedons.
COMPETING SERIES: This is the Klaber series. Klaber soils have 35 to 42 percent clay in the control section and have an albic horizon less than 6 inches thick.
GEOGRAPHIC SETTING: Klaber soils are in depressed positions on terraces and footslopes at elevations of 250 to 1,200 feet. These soils formed in mixed alluvium. Slopes are 0 to 8 percent. These soils occur in a climate with 40 to 70 inches average annual precipitation occurring mostly as rain in the winter. The average January temperature is 37 degrees F., average July temperature is 64 degrees F., and the average annual temperature is 50 degrees F. The frost-free season is 125 to 175 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Centralia, Galvin, Melbourne, Prather and Salkum soils and the competing Scamman soils. All of these soils have a xeric moisture regime. In addition, Centralia, Melbourne, and Salkum soils are well drained. Prather soils are moderately well drained. Galvin soils are somewhat poorly drained.
DRAINAGE AND PERMEABILITY: Poorly drained; medium runoff to ponded; slow permeability in the lower Btg horizon. A perched water table is from the surface to 0.5 feet from November to May unless drained.
USE AND VEGETATION: Used for woodland and pasture. Drained areas are used for hay, pasture, and small grains. Native vegetation is Douglas- fir, red alder, western hemlock, western red cedar, and Oregon ash, with an understory of hardhack, rose, salal, vine maple, western brackenfern, longtube twinflower, violet, trailing blackberry, red huckleberry, salmonberry, western hazel, and insideout flower.
DISTRIBUTION AND EXTENT: Western Washington. Series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lewis County, Washington, 1945.
REMARKS: Laboratory data available, Riverside Lab numbers 58159-58167 and 58168-58176. Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the surface to 7 inches, an albic horizon from 7 to 17 inches that interfingers into the upper 2 inches of the argillic horizon, and an argillic horizon from 17 to 75 inches.