LOCATION MISSION ID+MTEstablished Series
TAXONOMIC CLASS: Ashy, glassy, frigid Andic Fragiudalfs
TYPICAL PEDON: Mission ashy silt loam, woodland pasture; on a 1 percent slope at 2,120 feet elevation. When described on September 14, 1978, the soil was moist throughout. (Colors are for moist soil unless otherwise stated.)
Oi--0 to 1 inch; needles, leaves, and twigs.
Oe--1 to 2 inches; decomposed organic matter.
A--2 to 4 inches; dark brown (10YR 3/3) ashy silt loam, grayish brown (10YR 5/2) dry; weak medium subangular blocky structure parting to weak fine granular; soft, very friable, nonsticky and slightly plastic; many very fine and few fine, medium, and coarse roots; many very fine, common fine, and few medium tubular pores; neutral (pH 6.8); clear wavy boundary. (0 to 3 inches thick)
Bw1--4 to 8 inches; dark yellowish brown (10YR 3/4) ashy silt loam, yellowish brown (10YR 5/4) dry; weak medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common very fine and few fine, medium, and coarse roots; common very fine and few fine tubular pores; slightly acid (pH 6.5); clear wavy boundary. (3 to 8 inches thick)
Bw2--8 to 13 inches; dark yellowish brown (10YR 4/4) ashy silt loam, light yellowish brown (10YR 6/4) dry; weak medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic; many very fine and common fine, medium, and coarse roots; common very fine, fine, and few medium tubular pores; slightly acid (pH 6.1); abrupt wavy boundary. (3 to 7 inches thick)
2Btx--13 to 22 inches; mottled grayish brown (10YR 5/2) and brown (10YR 5/3) silt loam, mottled light gray (10YR 7/2) and pale brown (10YR 6/3) dry; weak very coarse prismatic structure parting to weak coarse angular blocky; very hard, very firm, slightly sticky and plastic; few very fine and fine flattened roots along exterior of peds; common very fine, fine, and few medium tubular pores; common distinct clay films on faces of peds and lining pores; dense and somewhat brittle; moderately acid (pH 6.0); abrupt wavy boundary. (6 to 15 inches thick)
2E--22 to 34 inches; light brownish gray (2.5Y 6/2) silt, light gray (2.5Y 7/2) dry; massive; hard, firm, nonsticky and slightly plastic; few very fine, fine, and medium roots; many very fine, common fine, and few medium tubular pores; common fine and medium faint yellowish brown (10YR 5/4) masses of iron accumulation; few faint clay films as bridges; moderately acid (pH 6.0); abrupt smooth boundary. (0 to 12 inches thick)
2Bt1--34 to 46 inches; yellowish brown (10YR 5/6) silt loam, light yellowish brown (10YR 6/4) dry; weak very coarse prismatic structure parting to weak coarse angular blocky; very hard, very firm, slightly sticky and plastic; few very fine and fine flattened roots along exterior of peds; common very fine, fine, and few medium tubular pores; common prominent light gray (10YR 7/2) silt coats, very pale brown (10YR 8/2) dry, on faces of peds; common distinct clay films on faces of peds and lining pores; strongly acid (pH 5.2); abrupt smooth boundary. (10 to 16 inches thick)
2Bt2--46 to 49 inches; light yellowish brown (10YR 6/4) silty clay loam, pale yellow (2.5Y 7/4) dry; weak very coarse angular blocky structure; very hard, very firm, sticky and plastic; common very fine and few fine flattened roots along exterior of peds; common very fine and few fine tubular pores; common prominent light gray (10YR 7/2) silt coats, pale yellow (2.5Y 8/2) dry, on faces of peds; common prominent clay films on faces of peds and lining pores; few distinct manganese stains; strongly acid (pH 5.2); abrupt smooth boundary. (0 to 8 inches thick)
3C1--49 to 51 inches; grayish brown (2.5Y 5/2) very fine sandy loam, pale yellow (2.5Y 7/4) dry; massive; slightly hard, friable, nonsticky and slightly plastic; few very fine roots; common very fine tubular pores; few fine faint light olive brown (2.5Y 5/4) masses of iron accumulation; strongly acid (pH 5.5); abrupt smooth boundary. (2 to 14 inches thick)
4C2--51 to 67 inches; grayish brown (2.5Y 5/2) fine sand, light yellowish brown (2.5Y 6/4) dry; massive; loose; few very fine, fine and medium roots; very porous; four firm yellowish brown (10YR 5/4) very fine sandy loam bands 1/4 inch thick; slightly acid (pH 6.3).
TYPE LOCATION: Bonner County, Idaho; approximately 3 miles north of Sandpoint; about 1,870 feet south and 2,275 feet west of the northeast corner sec. 3, T. 57 N., R. 2 W. Latitude - 48 degrees, 19 minutes, 23 seconds North; Longitude - 116 degrees, 33 minutes, 16 seconds West; USGS - Sandpoint quadrangle.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 44 to 46 degrees F.
Average summer soil temperature - 52 to 54 degrees F. with an O horizon
Depth to fragipan - 10 to 20 inches
Depth to seasonal perched water table - 6 to 18 inches (February to May)
Volcanic ash mantle - 7 to 13 inches thick
Volcanic glass content - 30 to 65 percent
Acid-oxalate extractable Al + 1/2 Fe - 1.0 to 3.0 percent
Phosphate retention - 55 to 90 percent
A horizon
Value - 4 or 5 dry, 2 through 4 moist
Chroma - 2 through 4 dry or moist
Texture - ashy SIL, ashy VFSL
Bulk density - 0.60 to 0.85 g/cc
Reaction - moderately acid to neutral
Bw horizon
Hue - 10YR or 7.5YR
Value - 5 through 7 dry, 3 through 5 moist
Texture - ashy SIL, ashy VFSL
Bulk density - 0.60 to 0.85 g/cc
Reaction - moderately acid to neutral
2Btx horizon
Hue - 10YR or 2.5Y
Value - 6 through 8 dry, 4 through 6 moist
Chroma - 2 to 4 dry or moist
Redoximorphic features - hue 2.5Y, or 10YR, value 4 or 5 moist, chroma 2 through 4 moist
Texture - SIL, SICL
Bulk density - 1.70 to 1.80 g/cc
Reaction - moderately acid to neutral
2E horizon
Hue - 10YR, 2.5Y, or 5Y
Value - 7 or 8 dry, 5 or 6 moist
Chroma - 2 through 4 dry or moist
Redoximorphic features - chroma 2 through 4 moist
Texture - SI, SIL, VFSL
Reaction - moderately acid or slightly acid
2Bt horizon
Hue - 10YR, 2.5Y, or 5Y
Value - 6 through 8 dry, 4 through 6 moist
Chroma - 2 through 4 dry, 2 through 6 moist
Redoximorphic features - hue 7.5YR, 10YR, 2.5Y, or 5Y, value 4 or 5 moist, chroma 1 through 8 moist
Texture - SIL, SICL, SIC
Reaction - strongly acid to neutral
3C and 4C horizons
Hue - 2.5Y or 5Y
Value - 6 through 8 dry, 4 through 6 moist
Chroma - 2 through 4 dry or moist
Redoximorphic features - hue 10YR, 7.5YR, 2.5Y, or 5Y, value 4 through 6 moist, chroma 1 through 8 moist
Texture - stratified VFSL, FS, LFS, SIL, SICL, SIC
Reaction - strongly acid to slightly alkaline
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Mission soils are on terraces and terrace escarpments. Slopes range from 0 to 30 percent. Elevations range from 2,050 to 2,500 feet. The soils formed in glaciolacustrine sediments and a mantle of volcanic ash. Average annual air temperature ranges from 43 to 45 degrees F; average annual precipitation ranges from 28 to 35 inches. The frost-free period is about 90 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bonner, Colburn, Odenson, Elmira, Hoodoo, Pend Oreille, Pywell, and Selle soils. All these soils lack a fragipan and an argillic horizon. Bonner, Colburn, Odenson, Elmira, and Selle soils are on terraces. Hoodoo and Pywell soils are on valley bottoms and flood plains. Pend Oreille soils are on foothills.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Runoff is slow on level areas and rapid on steeper areas. Permeability is very slow in the fragipan.
USE AND VEGETATION: These soils are used for cropland, hay, pasture, grazing, homesites, wildlife habitat, recreation, and woodland. Cultivated crops are alfalfa hay, grass-legume hay, and small grains. The natural vegetation is mainly western redcedar, western white pine, grand fir, western larch, Douglas-fir, ponderosa pine, paper birch, quaking aspen, and red alder with an understory of violet, goldthread, piper anemone, fairyslipper orchid, myrtle pachystima, rose, queencup beadlily, American trailplant, and fairybells.
DISTRIBUTION AND EXTENT: Northern Idaho and northwestern Montana, and possibly northeastern Washington. The soils of this series are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Stevens County, Washington, 1913.
REMARKS: Classification change from Ashy, frigid Andic Fragiboralfs to ashy, glassy, frigid Andic Fragiudalfs. This change is based on Soil Taxonomy 2nd Ed. Vegetation indicates udic moisture regime. It could also fit an Aquic subgroup.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 2 to 4 inches (A horizon)
Argillic horizon - the zone from 13 to 22 inches and 34 to 49 inches (2Btx, 2Bt1, and 2Bt2 horizons)
Fragipan - the zone from 13 to 22 inches (2Btx horizon)
Volcanic ash mantle - the zone from 2 to 13 inches (A, Bw1, and Bw2 horizons)
Redoximorphic features - start at 13 inches (2Btx horizon)
Particle-size control section - 2 to 13 inches (A, Bw1, and Bw2 horizons)
ADDITIONAL DATA: S78ID-017-011; 78P3271-3279.