LOCATION VOIGHT WAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Ultic Hapludalfs
TYPICAL PEDON: Voight silt loam - on a southwest-facing 8 percent slope under coniferous forest at 1,960 feet elevation. (Colors are for moist soil unless otherwise stated. All textures are apparent field textures. When described the soil was moist throughout.)
0i--10 to 7 inches; accumulation of needles, twigs, leaves, and bark.
0a--7 inches to 0; decomposed organic matter and rotted wood; many very fine, fine, medium and coarse roots.
A--0 to 11 inches; very dark grayish brown (10YR 3/2) silt loam, brown (10YR 5/3) dry; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots, common medium and coarse roots; many fine and very fine tubular pores; 5 percent angular pebbles; strongly acid (pH 5.2); clear smooth boundary. (3 to 15 inches thick)
Bt1--11 to 27 inches; brown (7.5YR 4/4) silty clay loam, light brown (7.5YR 6/4) dry; moderate medium subangular blocky structure; hard, firm, sticky and plastic; common very fine and fine roots; few medium and coarse roots; many fine and very fine pores; few faint patchy clay films on faces of peds and in pores; 5 percent angular pebbles; strongly acid (pH 5.4); gradual smooth boundary. (9 to 22 inches thick)
Bt2--27 to 43 inches; brown (7.5YR 4/4) silty clay loam, light brown (7.5YR 6/4) dry; weak moderate subangular blocky structure; hard, firm, sticky and plastic; few very fine, fine, and medium roots; many very fine and fine tubular pores; common distinct clay films in pores; 5 percent angular pebbles; strongly acid (pH 5.2); clear smooth boundary. (10 to 25 inches thick)
Bt3--43 to 58 inches; reddish brown (5YR 4/4) silty clay loam, reddish brown (5YR 5/4) dry; weak medium subangular blocky structure; very hard, firm, sticky and plastic; few very fine and fine roots; common very fine and fine tubular pores; common distinct clay films in pores; 5 percent angular pebbles; strongly acid (pH 5.4); clear smooth boundary. (0 to 25 inches thick)
C--58 to 65 inches; dark reddish brown (5YR 3/4) and brown (7.5YR 4/2) heavy silt loam, reddish brown (5YR 4/4) and light brownish gray (10YR 6/2) dry; massive; exhibits rock structure prior to rubbing; hard, firm, slightly sticky and plastic; few very fine tubular pores; 5 percent angular pebbles; moderately acid (pH 5.6).
TYPE LOCATION: Snoqualmie Pass Area, Pierce County, Washington; 50 feet northeast of Weyerhaeuser Road 1611A, 0.2 mile from the Koll Road intersection; 200 feet east and 550 feet south of the northwest corner, sec. 10, T. 16 N., R. 5 E.
RANGE IN CHARACTERISTICS: The average annual soil temperature is estimated to range from 43 to 46 degrees F. The solum is more than 40 inches thick. Depth to bedrock is more than 60 inches. The particle-size control section averages 27 to 35 percent clay and 15 to 35 percent materials coarser than very fine sand including 0 to 30 percent coarse fragments. Reaction ranges from strongly acid to moderately acid throughout.
The A horizon has value of 2 or 3 moist, 4 or 5 dry and chroma of 2 or 3 moist and dry. It has weak to strong subangular blocky or granular structure.
The Bt1 and Bt2 horizon have hue of 7.5YR or 10YR, value of 3 through 5 moist, 5 or 6 dry, and chroma of 3 to 6 moist and dry. It is silty clay loam, clay loam, or gravelly silty clay loam. These horizons have weak or moderate angular or subangular blocky structure. Clay films are faint or distinct.
The Bt3 horizon, where present, has hue of 5YR to 10YR, value of 4 or 5 moist, 5 to 7 dry, and chroma of 3 to 6 moist and dry. It is silty clay loam, gravelly silty clay loam, gravelly loam, silty clay loam, gravelly loam, silt loam, or gravelly silt loam, and has 0 to 35 percent coarse fragments.
The C horizon, where present, has hue of 5YR, 7.5YR, or 10YR, value of 3 to 5 moist, 4 to 6 dry, and chroma of 2 to 4 moist and dry. Some pedons have multiple colors resulting from strongly weathered coarse fragments. This horizon is silt loam, gravelly silt loam, loam, or gravelly loam and has 0 to 35 percent coarse fragments.
COMPETING SERIES: These are the Carrollton, Christoff, Floodwood(T), Jewett, Kinzua, and Watton series. Arland soils have a paralithic contact at a depth of 20 to 40 inches. Carrollton and Kinzua soils receive summer precipitation. Christoff soils have a mantle of volcanic ash 7 to 14 inches thick. Floodwood soils have an 11 to 18 inch thick mantle of volcanic ash and are 18 to 27 percent clay in the argillic horizon. Jewett soils have 18 to 25 percent clay in the particle-size control section and have a silt loam loess mantle 15 to 30 inches thick. Watton soils have an E horizon that qualifies as an albic horizon.
GEOGRAPHIC SETTING: The Voight soils are on uplands and mountainous areas in the foothills of the Cascade Mountains. Slopes are 5 to 65 percent. Elevations range from 1,700 to 2,800 feet. These soils formed in residuum and colluvium from andesite, basalt, and tuff breccia. The climate is marine influenced, with relatively cool dry summers and cool wet winters. The average annual precipitation is 60 to 90 inches, occurring mostly as snowfall and heavy rainfall during late autumn and winter. The average January temperature is about 30 degrees F; average July temperature is about 63 degrees F; and the average annual temperature is about 43 degrees F. The growing season (28 degrees F) is 130 to 175 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dobbs, Jonas, Mal, Mashel, Pheeney, Reichel, Scamman, Stahl, Vailton and Zynbar soils. Dobbs, Jonas, Vailton and Zynbar soils are medial and lack an argillic horizon. Mal soils are fine. Mashel and Scamman soils have a mesic temperature regime. Pheeney and Stahl soils are medial-skeletal. Reichel soils are medial. Reichel and Stahl soils have a cryic temperature regime.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Timber production, watershed, and wildlife habitat are the principal uses. The major tree species are Douglas-fir and western hemlock with scattered red alder, bigleaf maple, and western redcedar. Understory species are western swordfern, salal, red huckleberry, vine maple, salmonberry, Oregon-grape, western brackenfern, Oregon oxalis, trailing blackberry, deer fern, and Pacific trillium.
DISTRIBUTION AND EXTENT: West slope of the central Cascade Mountains in Washington. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lewis County, Washington, 1979.
REMARKS: Diagnostic horizons and features recognized in this pedon are an umbric epipedon from the mineral surface to 11 inches and an argillic horizon from 11 to 58 inches.