LOCATION PEND OREILLE ID+MTEstablished Series
TAXONOMIC CLASS: Ashy over loamy, glassy over mixed, superactive, frigid Alfic Udivitrands
TYPICAL PEDON: Pend Oreille ashy silt loam, forest; on a north-facing slope of 20 percent at 2,560 feet elevation. When described on April 28, 1976, the soil was moist throughout. (Colors are for dry soil unless otherwise stated.)
0i--0 to 1 inch; slightly decomposed needles and twigs. (0.5 to 2 inches thick)
0e--1 to 2 inches; moderately decomposed needles and twigs mixed with Mt. St. Helens volcanic ash. (0.5 to 1 inch thick)
A--2 to 6 inches; light yellowish brown (10YR 6/4) ashy silt loam, dark yellowish brown (10YR 3/4) moist; weak fine subangular blocky structure parting to strong very fine granular; soft, very friable, nonsticky and slightly plastic; many very fine, fine, and medium roots; many very fine irregular pores; 10 percent pebbles; neutral (pH 6.6); clear wavy boundary. (1 to 4 inches thick)
Bw1--6 to 15 inches; light yellowish brown (10YR 6/4) ashy silt loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure parting to strong very fine granular; soft, very friable, nonsticky and slightly plastic; many very fine, fine and medium roots; many very fine irregular pores; 10 percent pebbles; slightly acid (pH 6.1); clear wavy boundary. (7 to 14 inches thick)
Bw2--15 to 19 inches; light yellowish brown (10YR 6/4) ashy loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; soft, friable, nonsticky and slightly plastic; common very fine, fine, and medium roots; many very fine irregular pores; 5 percent pebbles; slightly acid (pH 6.1); clear wavy boundary. (3 to 10 inches thick)
2Bt1--19 to 30 inches; pale brown (10YR 6/3) gravelly sandy loam, brown (10YR 4/3) moist; massive: slightly hard, friable, nonsticky and nonplastic; common very fine, fine, and medium roots; many fine tubular pores; few faint clay films bridging mineral grains; 20 percent pebbles, 5 percent cobbles and stones; moderately acid (pH 6.0); clear wavy boundary.
2Bt2--30 to 43 inches; pale brown (10YR 6/3) gravelly sandy loam, brown (10YR 4/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; common very fine and fine roots; many fine tubular pores; few faint clay films bridging mineral grains; 20 percent pebbles, 5 percent cobbles and stones; slightly acid (pH 6.3); clear wavy boundary. (Combined thickness of 2Bt horizons is 10 to 42 inches)
2C--43 to 60 inches; very pale brown (10YR 7/3) very cobbly sandy loam, brown (10YR 5/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; common very fine and fine roots; many fine tubular pores; 15 percent pebbles, 20 percent cobbles and stones; slightly acid (pH 6.4).
TYPE LOCATION: Bonner County, Idaho; about 5.8 miles west of U. S. Highway 95 on Springy Point Road, one mile south of junction with first county road; about 50 feet south and 1,300 feet west of the northeast corner, sec. 7, T. 56 N., R. 2 W.; Latitude - 48 degrees, 13 minutes, 21 seconds North; Longitude - 116 degrees, 36 minutes, 54 seconds West; USGS Sagle Quadrangle.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 42 to 46 degrees F.
Average summer soil temperature - 47 to 53 degrees F. with an O horizon
Solum thickness - 36 to 60 inches
Moisture control section - dry 15 to 30 days (August to mid September), moist mid September through July; udic moisture regime
Surface boulders - 0 to 3 percent
Volcanic ash mantle - 14 to 20 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
15 bar water (air dried) - 7 to 12 percent
Reaction - moderately acid to neutral throughout
A horizon
Value - 4 to 6 dry, 2 or 3 moist
Chroma - 2 to 4 dry or moist
Texture - ASHY-SIL, ASHY-L, GR-ASHY-SIL
Clay content - 3 to 8 percent
Rock fragments - 0 to 20 percent
Bulk density - 0.65 to 1.00 g/cc
Bw horizons
Hue - 10YR or 7.5YR
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 to 6 dry or moist
Texture - ASHY-SIL, ASHY-L, GR-ASHY-SIL, GR-ASHY-L, CB-ASHY-SIL in lower part
Clay content - 3 to 8 percent
Rock fragments - 0 to 25 percent
Bulk density - 0.65 to 1.00 g/cc
2Bt horizons
Hue - 2.5Y or 10YR
Value - 6 or 7 dry, 4 or 5 dry
Chroma - 3 or 4 dry or moist
Texture - GR-SL, CB-SL, CB-L, GR-L, GR-FSL, CB-FSL
Clay content - 3 to 8 percent
Rock fragments - 15 to 35 percent
Lamellae - (present in some pedons) 2mm to 1.5 cm thick
2C horizon
Hue - 2.5Y or 10YR
Value - 6 to 8 dry, 5 or 6 moist
Chroma - 2 to 4 dry or moist
Texture - GR-SL, CB-SL, GR-LS, CB-LS, GRV-SL, CBV-SL, GRV-LS, CBV-LS
Clay content - 2 to 5 percent
Rock fragments - 25 to 50 percent
COMPETING SERIES: These are the Idamont and Zee series. Idamont soils have 3C horizons with extremely gravelly sandy loam textures. Zee soils have 18 to 22 percent clay in the 2Bt horizon.
GEOGRAPHIC SETTING: Pend Oreille soils are on foothills, mountain slopes, outwash terraces and lateral moraines. Slopes range from 2 to 65 percent. They formed in glacial till from granite, gneiss, and schist with a thick mantle of volcanic ash. Elevations range from 2,000 to 4,800 feet. The average annual air temperature ranges from 42 to 45 degrees F. and average annual precipitation ranges from 30 to 45 inches. The average frost-free period is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ardtoo, Bonner, Dufort, Hoodoo, Sagle, Stien, Treble, and Vay soils. Ardtoo soils are on south-facing mountain slopes and are loamy-skeletal. Bonner soils are on terraces and are sandy or sandy-skeletal. Dufort soils are on foothills and mountain slopes and are ashy over loamy-skeletal. Hoodoo soils are in drainageways and valley bottoms and are poorly drained. Sagle soils are on foot slopes and toe slopes and are somewhat poorly drained. Stien soils are on terraces and moraines and are ashy-skeletal. Treble soils are on foothills and mountain slopes and are loamy-skeletal. Vay soils are on mountain slopes and are cryic.
DRAINAGE AND PERMEABILITY: Well drained; Runoff is slow to rapid; Permeability is moderate in the upper part and moderately rapid below.
USE AND VEGETATION: These soils are used for timber production, grazing, hay and pasture, wildlife habitat, and recreation. A few areas are used for homesites. Natural vegetation is mainly western redcedar, grand fir, Douglas-fir, western larch, western white pine, ponderosa pine, lodgepole pine, and birch with an understory of myrtle pachystima, big blueberry, longtube twinflower, queencup beadlily, starry false Solomons seal, American trailplant, goldthread, fairybells, and common princes pine. Some areas with cooler temperatures have western hemlock.
DISTRIBUTION AND EXTENT: Northern Idaho, northwestern Montana, and possibly northeastern Washington. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Bonner County, Idaho, 1936.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the mineral soil surface to 7 inches (A and part of Bw1 horizons)
Cambic horizon - the zone from 6 to 19 inches (Bw1 and Bw2 horizons)
Argillic horizon - the zone from 19 to 43 inches (2Bt1 and 2Bt2 horizons)
Volcanic ash mantle - the zone from 2 to 19 inches (A, Bw1, and Bw2 horizons)
Particle-size control section - the zone from the mineral soil surface to 40 inches (A, Bw1, Bw2, 2Bt1 and part of the 2Bt2 horizon)