LOCATION COLBURN ID+WAEstablished Series
TAXONOMIC CLASS: Coarse-loamy over sandy or sandy-skeletal, mixed, superactive, frigid Aquandic Haploxerepts
TYPICAL PEDON: Colburn ashy very fine sandy loam - on a 1 percent slope in a pasture, at 2,140 feet elevation. (Colors are for moist soil unless otherwise noted).
A--0 to 3 inches; dark brown (10YR 3/3) ashy very fine sandy loam, brown (10YR 5/3) dry; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine tubular and interstitial pores; few fine and medium manganese concretions; slightly acid (pH 6.2); abrupt smooth boundary. (1 to 4 inches thick)
Bwc1--3 to 6 inches; brown (7.5YR 4/4) ashy very fine sandy loam, light yellowish brown (10YR 6/4) dry; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; few very fine and fine tubular pores; many very fine and few fine and medium manganese concretions; slightly acid (pH 6.4); clear smooth boundary. (3 to 6 inches thick)
Bwc2--6 to 12 inches; brown (7.5YR 4/4) ashy very fine sandy loam, light yellowish brown (10YR 6/4) dry; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; few very fine tubular pores; common very fine, fine, and few medium manganese concretions; slightly acid (pH 6.4); clear smooth boundary. (4 to 6 inches thick)
Bwc3--12 to 18 inches; dark yellowish brown (10YR 4/4) ashy very fine sandy loam, light yellowish brown (10YR 6/4) dry; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; few very fine tubular pores; few very fine manganese concretions; neutral (pH 6.6); abrupt smooth boundary. (4 to 6 inches thick)
Bt--18 to 20 inches; brown (10YR 4/3) silt loam, very pale brown (10YR 7/3) dry; moderate fine and medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine roots; few very fine and fine tubular pores; few faint clay films on faces of peds; few fine prominent strong brown (7.5YR 5/8) redox concentrations; neutral (pH 7.0); abrupt wavy boundary. (0 to 4 inches thick)
2Btg1--20 to 24 inches; light brownish gray (2.5Y 6/2) fine sandy loam, light gray (2.5Y 7/2) dry; massive; hard, firm, slightly sticky and slightly plastic; few very fine roots; few very fine tubular pores; few faint clay films as bridges between mineral grains; one brown (10YR 4/3) clay band 1/4 inch thick; many fine prominent strong brown (7.5YR 5/8) and common medium distinct light olive brown (2.5Y 5/4) redox concentrations; neutral (pH 7.0); abrupt wavy boundary. (3 to 5 inches thick)
2Btg2--24 to 29 inches; light olive gray (5Y 6/2) loamy fine sand, light gray (5Y 7/2) dry; massive; slightly hard, friable; nonsticky and nonplastic; common very fine tubular pores; two brown (10YR 4/3) and brown (7.5YR 4/4) clay bands 1/4 and 1/2 inch thick; many fine prominent strong brown (7.5YR 5/8) and common medium distinct light olive brown (2.5Y 5/4) redox concentrations; neutral (pH 6.6); clear wavy boundary. (5 to 16 inches thick)
2Cg1--29 to 48 inches; light brownish gray (2.5Y 6/2) fine sand, light gray (5Y 7/2) dry; single grain; loose, very friable; nonsticky and nonplastic; many very fine interstitial pores; common medium prominent strong brown (7.5YR 5/6) redox concentrations; slightly acid (pH 6.4); gradual smooth boundary. (10 to 20 inches thick)
2Cg2--48 to 65 inches; grayish brown (2.5Y 5/2) fine sand, light gray (5Y 7/2) dry; single grain; loose, very friable; nonsticky and nonplastic; many very fine interstitial pores; many medium and large prominent strong brown (7.5YR 5/6) redox concentrations; neutral (pH 7.0).
TYPE LOCATION: Bonner County, Idaho; about 1.5 miles east of Samuels, about 40 feet north and 375 feet east of the southwest corner of sec. 27, T. 59 N, R. 1 W. Latitude - 48 degrees, 25 minutes, 45.8 seconds N., Longitude - 116 degrees, 27 minutes, 36.8 seconds W., NAD 83. USGS Elmira, Idaho quadrangle.
RANGE IN CHARACTERISTICS:
Depth to water table - February through May - 20 to 36 inches, June through January - greater than 36 inches
Moisture control section - dry 45 to 60 days, July to September. Moist - October to June
Average annual soil temperature - 43 to 45 degrees F.
Average summer soil temperature - 55 to 59 degrees F. without an O horizon and in saturated soil
Reaction - moderately acid to neutral
Volcanic ash influence - 12 to 20 inches
Estimated properties of the volcanic ash influenced layers:
Volcanic glass content in the 0.02 to 2mm fraction - 5 to 20 percent
Acid-oxalate extractable Al = 1/2Fe 0.4 to 1.0 percent
Moist bulk density - 1.15 to 1.35 g/cc
A horizon
Value - 2 or 3 moist, 4 or 5 dry
Chroma - 1 to 3 moist or dry
Texture - ashy very fine sandy loam, ashy silt loam, or ashy fine sandy loam
Bwc or Bw horizon
Value - 4 or 5 moist, 6 or 7 dry
Texture - ashy very fine sandy loam or ashy silt loam
Bt horizon (when present)
Value - 4 or 5 moist, 6 or 7 dry
2Btg horizon
Hue - 10YR, 2.5Y or 5Y
Value - 5 or 6 moist, 7 or 8 dry
Redox features contrast - faint to prominent
Hue - 7.5YR, 10YR, or 2.5Y
2Cg horizon
Hue - 10YR, 2.5Y or 5Y
Value - 5 or 6 moist, 7 or 8 dry
Chroma - 1 or 2 moist
Redox features contrast - faint to prominent
Hue - 7.5YR, 10YR, or 2.5Y
Value - 4 to 6 moist
Chroma - 2 to 8 moist
Coarse fragments - 0 to 35 percent gravel; stratified with thin layers of coarse sand and gravel in some pedons
Texture - loamy sand or fine sand in the lower part
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Colburn soils are on low alluvial fans and terraces adjacent to flood plains at elevations of 2,075 to 2,300 feet. The slope range is 0 to 4 percent. The soils formed in mixed alluvium weathered from granitic and metasedimentary rocks with an influence of volcanic ash in the upper part. The average annual temperature is 42 to 45 degrees F. The average annual precipitation is 30 to 35 inches. The frost-free season is about 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bonner, Capehorn, Elmira, Mission, Odenson, Pend Oreille, Sagle, and Selle series. Bonner and Pend Oreille soils are well drained and have high amounts of volcanic ash in the upper part. Capehorn soils are poorly drained. Elmira soils are excessively drained and sandy throughout. Mission soils have a fragipan and an argillic horizon. Odenson soils have high amounts of volcanic ash in the upper part. Selle soils are well drained and have base saturation less than 60 percent.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; moderate permeability in the solum and moderately rapid or rapid in the substratum.
USE AND VEGETATION: These soils are used for hay, pasture, small grains, woodland, grazing, and recreation. Some of the soils are irrigated. Natural vegetation is mainly western redcedar, grand fir, western white pine, western larch, Douglas-fir, lodgepole pine, quaking aspen, black cottonwood, and paper birch with an understory of Sitka alder, brackenfern, common snowberry, myrtle pachystima, goldthread, starry false-Solomons-seal, and northern twinflower.
DISTRIBUTION AND EXTENT: Northern Idaho and northeastern Washington. MLRA 44A. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Bonner County, Idaho, 1939.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon - the zone from 0 to 3 inches (A horizon)
Cambic horizon - the zone from 3 to 29 inches with faint clay films present between 18 and 29 inches but assumed to lack the clay increase needed for an argillic horizon (Bwc1, Bwc2, and Bwc3, Bt, 2Btg1, and 2Btg2 horizons)
Particle-size control section - the zone from 10 to 40 inches (part of the Bwc1, Bwc2, Bwc3, Bt, 2Btg1, 2Btg2 and part of the 2Cg1 horizon)
Aquic conditions and estimated redox depletions with chroma 2 or less - starting at 20 inches (2Btg1 horizon)
This pedon meets the requirements for a lamellic subgroup - the zone from 24 to 29 inches (2Btg1 horizon)
Ash influence - the zone from 0 to 12 inches and assumed to be present based on associated soils and convention used in Idaho of Bir horizonation equating to ash material.
Classification revised 11/01 from Aquic Xerochrepts to Aquic Dystroxerepts based on revisions to Soil Taxonomy. Classification revised 3/04 from coarse-loamy over sandy or sandy-skeletal, mixed, superactive, frigid Aquic Dystroxerepts to coarse-loamy over sandy or sandy-skeletal, mixed, superactive, frigid Aquandic Dystroxerepts based on associated soils with ash influence and Bir convention.
Note: Further investigation needed as to the degree and depth of ash influence and whether andic soil properties are met. This soil may possible meet Andisol criteria and isotic mineralogy.
Further investigation is needed to determine soil moisture regime concept based on vegetation documented. Vegetation listed suggests more of an aquic - udic soil moisture regime and perhaps a Eutrudepts great group.
The 2/2009 revision reflects a change in great group from Dystroxerepts to Haploxerepts based on an evaluation of lab data on similar soils.