LOCATION VANZANDT WAEstablished Series
TAXONOMIC CLASS: Medial-skeletal, mixed, mesic Aquic Vitrixerands
TYPICAL PEDON: Vanzandt gravelly loam - on a 13 percent west-facing slope under a coniferous canopy. (Colors are for moist soil unless otherwise stated. All textures are apparent field textures.)
Oi--1 inch to 0; undecomposed needles, leaves and twigs; many medium roots.
A--0 to 1 1/2 inches; dark brown (7.5YR 3/2) very gravelly silt loam, brown (7.5YR 5/2) dry; weak fine granular structure; soft, very friable, slightly sticky, slightly plastic, and weakly smeary; common medium and coarse roots; many fine irregular pores; 25 percent hard pebbles and 20 percent channers; strongly acid (pH 5.2); clear smooth boundary. (1/2 to 2 inches thick)
Bs1--1 1/2 to 10 inches; dark brown (7.5YR 4/4) very gravelly loam, light yellowish brown (10YR 6/4) dry; weak fine subangular blocky structure; soft, very friable, slightly sticky, slightly plastic; and weakly smeary; many very fine, fine, medium, and coarse roots; many fine irregular pores; 25 percent hard pebbles and 10 percent channers; NaF pH 11.0, moderately acid (pH 5.8); abrupt smooth boundary. (4 to 11 inches thick)
Bs2--10 to 23 inches; dark yellowish brown (10YR 4/4) very gravelly loam, very pale brown (10YR 7/4) dry; weak fine and medium subangular blocky structure; soft; friable, nonsticky, nonplastic, and weakly smeary; many fine, medium and coarse roots; many fine irregular pores; 40 percent hard pebbles and 10 percent soft pebbles; NaF pH 11.0, moderately acid (pH 5.9); clear smooth boundary. (8 to 15 inches thick)
C--23 to 31 inches; light yellowish brown (2.5Y 6/4) very gravelly loam, white (2.5Y 8/2) dry; few fine prominent mottles of strong brown (7.5YR 5/6) reddish yellow (7.5YR 6/6) dry; massive; slightly hard, friable, nonsticky and nonplastic; many fine and medium roots; common fine irregular pores; 30 percent hard pebbles and 10 percent channers; NaF pH 9.6, moderately acid (pH 5.9); abrupt smooth boundary. (7 to 21 inches thick)
2Cd--31 to 60 inches; light brownish gray (2.5Y 6/2) dense glacial till that breaks to very gravelly loam, white (2.5Y 8/2) dry; common fine prominent mottles of strong brown (7.5YR 5/6), reddish yellow (7.5YR 6/6) dry; massive; very hard, very firm, nonsticky and nonplastic; few fine irregular pores; 35 percent hard pebbles, 10 percent channers, NaF pH 10.0; moderately acid (pH 5.9).
TYPE LOCATION: Whatcom County, Washington, about 2 miles northeast of Acme; 400 feet south and 2,200 feet east of the northwest corner of sec. 33, T. 38 N., R. 5 E.
RANGE IN CHARACTERISTICS: Mean annual soil temperature ranges from 47 to 52 degrees F. Depth of a paralithic contact with dense glacial till ranges from 20 to 40 inches. Thickness of the solum and the volcanic ash influence is 17 to 28 inches. The soil moisture control section is dry in all parts for 60 to 75 consecutive days within the four months that follow the summer solstice in 6 or more years out of 10. Clay content in the lower part of the control section is 10 to 15 percent. The upper part of the control section averages 40 to 50 percent hard rock fragments and 0 to 10 percent soft pebbles. The lower part of the control section averages 40 to 60 percent rock fragments which include pebbles, channers, and cobbles.
The A horizon has hue of 7.5YR or 10YR, value of 3 or 4 moist, 4 through 6 dry, and chroma of 2 through 4 moist and dry. Some pedons have an a horizon and lack an A horizon. Reaction is strongly acid to slightly acid.
The Bs horizon has hue of 5YR or 10YR, value of 3 through 5 moist, 5 through 7 dry, and chroma of 3 through 6 moist and dry. It is very gravelly loam or very gravelly silt loam. Reaction is moderately acid or slightly acid. Some pedons have a BC horizon.
The C horizon has hue of 2.5Y or 5Y, value of 4 through 8 moist, 6 through 8 dry, and chroma of 2 through 4 moist and dry. It is very gravelly loam or very gravelly sandy loam. It is moderately acid or slightly acid.
The 2Cd horizon has hue of 2,5Y or 5Y, value of 4 through 8 moist, 5 through 8 dry, and chroma of 1 through 4 moist and dry. It is dense glacial till that breaks to very gravelly loam or very gravelly sandy loam. Rock fragments range from 35 to 50 percent.
COMPETING SERIES: These are the Ahl, Barnhardt, Pickett, Squires, and Tunnel series and the similar Blethen, Heisler, Lyre, Neer, Ogarty, and Swinomish soils. The Ahl, Ogarty, Pickett, Squires, and Tunnel soils are 20 to 40 inches deep to a lithic contact. Barnhardt, Blethen, Heisler, and Lyre soils lack a paralithic contact within depths of 60 inches. Neer soils lack a C horizon and are dry for 75 to 95 consecutive days following summer solstice. Swinomish soils are dry for 75 to 90 consecutive days following summer solstice.
GEOGRAPHIC SETTING: Vanzandt soils are on glacially modified slopes and valleys at elevations of 250 to 1,500 feet. Slopes are 0 to 65 percent. These soils formed in volcanic ash and glacial till and slope alluvium and colluvium containing volcanic ash and glacial till. Summers are warm and dry. Winters are cool and moist with intermittent snow cover. Mean annual precipitation is 45 to 70 inches. Mean January temperature is about 35 degrees F, mean July temperature is about 62 degrees F. Mean annual temperature is about 46 degrees F. The frost-free season is 140 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Barneston, Montborne, Rinker, and Sehome soils and the competing Heisler and Squires soils. Barneston soils are deep and are sandy-skeletal. Montborne and Rinker soils have a frigid temperature regime. Sehome soils are coarse-loamy.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow to rapid runoff; moderate permeability above the dense glacial till and very slow through it. A perched water table is as high as 2 to 3 feet at times from December through April.
USE AND VEGETATION: Used for timber production, wildlife habitat, and some cropland and homesites. Vegetation is Douglas-fir, western hemlock, western redcedar, bigleaf maple, and red alder, with an understory of Oregon-grape, salal, western swordfern, Pacific trillium, trailing blackberry, western brackenfern, longtube twinflower, vanilla leaf, vine maple, red huckleberry, and salmonberry.
DISTRIBUTION AND EXTENT: Northwestern Washington. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skagit County Area, Washington, 1981.
REMARKS: Classification only changed 4/94 because of recent amendments to Soil Taxonomy, except the Cr horizon was changed to Cd and remarks were modified. This draft reflects a change in classification from medial-skeletal, mesic Andic Xerochrepts to loamy-skeletal, mixed, mesic Typic Haplorthods. Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the mineral surface to 1 1/2 inches, a cambic horizon from 1 1/2 to 23 inches, andic soil properties from 0 to 23 inches, and a paralithic contact with dense glacial till at 31 inches. Estimated 15 bar water retention at 12-15 percent based on lab data from Squires pedon #81P529.