LOCATION VANBRUNT WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic, mesic Vitrandic Haploxerolls
TYPICAL PEDON: Vanbrunt very stony ashy sandy loam - on a 48 percent southeast facing slope, under a sparse ponderosa pine canopy, at 2,980 feet elevation. (Colors are for dry soil unless otherwise stated.)
Oi--0 to 1.75 inches; needles, twigs, leaves, and cones.
Oe--1.75 to 2.00 inches; partially decomposed needles, twigs, and leaves; abrupt smooth boundary.
A1--2 to 5 inches; brown (10YR 5/3) very stony ashy sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, very friable, slightly sticky, slightly plastic; many very fine and fine roots; common medium and coarse roots; 25 percent gravel, 5 percent cobbles, 5 percent surface stones; moderately acid (pH 5.6); clear smooth boundary.
A2--5 to 12 inches; brown (10YR 5/3) very gravelly ashy sandy loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky, slightly plastic; many very fine and fine roots, common medium and coarse roots; 30 percent gravel, 10 percent cobbles; moderately acid (pH 6.0); clear wavy boundary. (Combined thickness of the A horizon is 7 to 13 inches.)
Bw--12 to 21 inches; light yellowish brown (10YR 6/4) extremely cobbly sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky, nonplastic; few very fine, fine, medium, and coarse roots; 35 percent gravel, 25 percent cobbles; moderately acid acid (pH 6.0); clear wavy boundary. (8 to 12 inch thick)
C--21 to 27 inches; very pale brown (10YR 7/3) very cobbly sandy loam, yellowish brown (10YR 5/4) dry; massive; soft, very friable, slightly sticky, slightly plastic; few very fine, fine, and medium roots; 35 percent gravel, 20 percent cobbles; slightly acid (pH 6.2); abrupt wavy boundary. (0 to 17 inches thick)
R--27 inches; fractured quartz monzonite; fractures greater than 4 inches apart.
TYPE LOCATION: Okanogan County, Washington; about 4 miles northwest of the town of Nespelem; 2,050 feet south, 550 feet west of the northeast corner of section 16, T. 3l N., R. 30 E., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches ranges from 47 to 50 degrees F. These soils are usually moist but are dry in all parts between a depth of 8 and 24 inches (or lithic contact) for 75 to 90 consecutive days following the summer solstice. Solum is 16 to 25 inches thick. Depth to a lithic contact ranges from 20 to 40 inches. The upper 7 to 19 inches has an estimated moist bulk density of 1.30 to 1.40 g/cc, volcanic glass content of 5 to 20 percent, acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of 0.4 to 1.0 percent, and 15-bar water retention of 5 to 10 percent for air dried samples. The particle-size control section contains 3 to 8 percent clay and 35 to 70 percent rock fragments. Reaction is moderately acid to neutral throughout.
The A horizon has value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3 dry or moist. It is stony, very stony, or very bouldery. This horizon is 10 to 30 percent gravel, 0 to 25 percent cobbles. The surface is covered by 1 to 10 percent stones and boulders.
The Bw horizon has value of 6 or 7 dry, 4 or 5 moist. It is very gravelly, very cobbly, extremely cobbly, or extremely gravelly. This horizon is 20 to 40 percent gravel, 10 to 40 percent cobbles, and 0 to 10 percent stones.
The C horizon has value of 6 or 7 dry, 4 or 5 moist, and chroma of 2 or 3 dry or moist. It is extremely gravelly, very cobbly, or extremely cobbly. This horizon is 20 to 50 percent gravel, 15 to 30 percent cobbles, and 0 to 10 percent stones.
COMPETING SERIES: These are the Borgeau, Emily, Lenz, Louiecreek, Raisio, Sinlahekin, Speigle, and Whitestone series. Borgeau, Emily,Louiecreek, Sinlakekin, Speigle, and Whitestone soils are deeper than 40 inches to a lithic contact. Lenz soils have more than 8 percent clay in the particle-size control section. Raisio soils are 35 to 80 percent shaly fragments and flagstones.
GEOGRAPHIC SETTING: Vanbrunt soils are on mountain ridges, shoulders, and backslopes. These soils formed in colluvium and residuum from granitic rocks, with a component of loess and volcanic ash. Rock fragments and bedrock consist of granodiorite, quartz monzonite, diorite, and granitic gneiss. In glaciated areas, these soils also contain a small component of granitic glacial till. Slopes are 5 to 65 percent. Elevations range from 1,800 to 4,600 feet. The climate is characterized by warm, dry summers and cold, moist winters. The average annual precipitation ranges from 12 to 20 inches. The mean January temperature is about 25 degrees F, mean July temperature is about 69 degrees F, and the mean annual air temperature is about 47 degrees F. The frost-free season is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Donavan, Merkel, Mineral, Republic, Whitestone, and Swakane soils. Donavan, Merkel, Republic, and Whitestone soils are greater than 60 inches to bedrock. In addition, Merkel and Republic soils are frigid. Donavan and Whitestone soils are on toeslopes, footslopes, and backslopes of foothills and mountains. Merkel soils are on mountains. Republic soils are on alluvial fans, terraces and backslopes and footslopes of mountains. Mineral soils are 20 to 40 inches to bedrock, are frigid, and are on mountainsides and ridges. Swakane soils are 10 to 20 inches to bedrock, are mesic, and are on uplands, hills and mountains.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability.
USE AND VEGETATION: Grazing, wildlife habitat, limited timber production, and watersheds are the principal uses. The native vegetation is ponderosa pine, antelope bitterbrush, Saskatoon serviceberry, bluebunch wheatgrass, Idaho fescue, arrowleaf balsamroot, and common yarrow.
DISTRIBUTION AND EXTENT: North-central Washington. MLRA 6, 43A. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Colville Indian Reservation, Okanogan County, Washington, 1987.
REMARKS: Diagnostic horizons and features recognized in this soil are a mollic epipedon from 2 to 12 inches, a cambic horizon from 12 to 21 inches, and 58 percent rock fragments in the particle-size control section from 12 to 27 inches. The description reflects a change in classification due to Andisols, from loamy-skeletal, mixed, mesic Ultic Haploxerolls to loamy-skeletal, mixed, mesic Vitrandic Haploxerolls.