LOCATION SCAND IDEstablished Series
TAXONOMIC CLASS: Ashy over loamy, amorphic over mixed, superactive, frigid Alfic Udivitrands
TYPICAL PEDON: Scand ashy silt loam, forested, on a 35 percent slope at 3,020 feet elevation. Aspect is east. When described on August 18, 1999 the soil was moist throughout. (Colors are for dry soil unless otherwise indicated)
Oi--0 to 1 inch; slightly decomposed needles, twigs, leaves and moss; abrupt wavy boundary. (1 to 2 inches thick)
A--1 to 4 inches; light brown (7.5YR 6/4) ashy silt loam, brown (7.5YR 4/4) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots throughout; many very fine and fine irregular pores; moderately acid (pH 5.7); clear wavy boundary. (2 to 4 inches thick)
Bw--4 to 16 inches; light brown (7.5YR 6/3) ashy silt loam, brown (7.5YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and common medium roots throughout; many very fine and fine irregular pores; moderately acid (pH 5.8); abrupt wavy boundary. (12 to 15 inches thick)
2Bt1--16 to 21 inches; very pale brown (10YR 7/3) silt loam, brown (10YR 5/3) moist; moderate fine subangular blocky structure parting to weak fine subangular blocky; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine and common medium roots throughout; many very fine and fine irregular pores; few faint clay films on faces of peds; 10 percent fine mica flakes; 5 percent schist gravel; strongly acid (pH 5.5); clear wavy boundary.
2Bt2--21 to 27 inches; light yellowish brown (10YR 6/4) silt loam, yellowish brown (10YR 5/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine to medium roots throughout; common very fine and fine irregular and tubular pores; few faint clay films on faces of peds; 20 percent fine mica flakes; 5 percent schist gravel; very strongly acid (pH 4.9); clear wavy boundary. (2Bt horizons 11 to 34 inches thick)
3Bt3--27 to 38 inches; light yellowish brown (10YR 6/4) loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common very fine and fine roots throughout; common very fine and fine irregular and tubular pores; common faint clay films on faces of peds; 35 percent fine mica flakes; 10 percent schist gravel; very strongly acid (pH 5.0); clear wavy boundary.
3Bt4--38 to 45 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few very fine and fine roots throughout; common very fine and fine irregular and tubular pores; many distinct dark brown (7.5YR 3/4) clay films on faces of peds; 40 percent fine mica flakes; 10 percent schist gravel; strongly acid (pH 5.1); clear wavy boundary.
3Bt5--45 to 53 inches; brown (7.5YR 5/4) loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few very fine and fine roots throughout; common very fine and fine irregular and tubular pores; many distinct dark brown (7.5YR 3/4) clay films on faces of peds; 50 percent fine mica flakes; 10 percent schist gravel; very strongly acid (pH 5.0); clear wavy boundary. (3Bt horizons 4 to 26 inches thick)
3BC--53 to 63 inches; strong brown (7.5YR 5/6) loamy sand, strong brown (7.5YR 4/6) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots throughout; common very fine and fine irregular and tubular pores; 55 percent fine mica flakes; 10 percent schist gravel; strongly acid (pH 5.1).
TYPE LOCATION: Latah County, Idaho; about 6 miles northeast of Southwick, Idaho; about 1200 feet north and 2450 feet east of the southwest corner of Sec. 29, T39N, R1E; Latitude - 46 degrees, 41 minutes, 28 seconds North; Longitude - 116 degrees, 21 minutes, 45 seconds West; USGS Aldermand Ridge Quadrangle.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 39 to 45 degrees F (Frigid temperature regime)
Soil moisture control section - not dry for 45 consecutive days from June to October (Udic moisture regime)
Mica content of 3Bt, 3BC and 3C horizons - 30 to 85 percent by volume
Thickness of volcanic ash cap - 14 to 19 inches
Volcanic glass - 15 to 50 percent
Acid-oxalate extractable Al+1/2 Fe - 1.5 to 2.7 percent
Phosphorous retention - 55 to 90 percent
15 bar water retention - 8 to 17 percent on air dried samples; weighted average less than 15 percent
A horizon
Hue - 7.5YR or 10YR dry or moist
Value 4 to 6 dry, 2 to 4 moist
Chroma 2 to 4 dry or moist
Clay content - 8 to 10 percent
Reaction very strongly acid to slightly acid
Bulk density - 0.50 to 0.90 g/cc
Bw horizon
Hue - 7.5YR or 10YR dry or moist
Value 3 to 7 dry, 3 to 6 moist
Chroma - 3 to 6 dry or moist
Clay content - 8 to 10 percent
Reaction strongly acid to neutral
Bulk density - 0.65 to 1.00 g/cc
2EB horizons (where present)
Hue - 7.5YR moist
Value 6 or 7 dry, 3 to 5 moist
Chroma - 3 or 4 dry or moist
Texture - SIL
Clay content - 18 to 22 percent
Rock fragments - 0 to 13 percent gravel
Reaction - strongly acid to moderately acid
Mica content 0 to 15 percent
2Bt horizons
Hue - 7.5YR or 10YR moist
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 3 or 4 dry, 2 to 6 moist
Texture - SIL, L, GR-SIL
Clay content - 12 to 25 percent
Rock fragments - 0 to 30 percent gravel
Reaction - very strongly acid to moderately acid
Mica content 0 to 25 percent
3Bt horizons
Hue - 7.5YR or 10YR dry or moist
Value 4 to 6 dry, 3 to 5 moist
Chroma 3 to 6 dry or moist
Texture - L, SCL, FSL, LS, GR-L, GRV-SL, VFSL, GR-SL
Clay content - 12 to 26 percent
Rock fragments - 0 to 10 percent gravel
Reaction - very strongly acid or strongly acid
Mica content 30 to 50 percent
3BC and 3C horizons (where present)
Hue 5YR to 10YR dry or moist
Value - 4 to 7 dry, 3 to 5 moist
Chroma - 4 or 6 dry, 4 to 8 moist
Texture - L, PGRV-L, GR-SL, FSL, GR-SL, GRX-SL, GRV-L, GRV-SL, LS, GRV-FSL
Clay content - 7 to 24 percent
Rock fragments - 0 to 90 percent gravel, 0 to 5 percent cobbles, 0 to 45 percent paragravel, 0 to 90 percent total rock fragments, 0 to 45 percent total pararock fragments
Reaction - strongly acid TO moderately acid
Mica content 30 to 75 percent
COMPETING SERIES: These are the Brodeer, Chesley, Cranberry, Disalto, Dworshak, and Helmer series. Chesley soils are deep to a paralithic contact. Cranberry soils have textures finer than loam in the 3Bt horizons and have less than 30 percent fine mica flakes. Disalto soils have less than 15 percent mica throughout. Brodeer soils do not have a 3Bt or BC horizon. Dworshak soils have less than 30 percent fine mica flakes. Helmer soils are shallow to a fragipan.
GEOGRAPHIC SETTING: Scand series are on structural benches, mountain slopes and ridges at elevations of 1,600 to 4,200 feet. They have slopes of 15 to 60 percent. These soils formed in loess over residuum from high mica schist and gneiss with a thick mantle of volcanic ash. The average annual air temperature is 38 to 44 degrees F. The average annual precipitation is 30 to 55 inches. The frost-free season is 50 to 110 days (9 years in 10 to 1 year in 10, respectively).
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Grandad, Lado, Norwidge, Poorman, Scaler and Threebear soils. Grandad soils are on mountain slopes and ridge tops, and lack a 3Bt or 3BC horizon. Lado soils are on mountain slopes and have less than 30 percent fine mica flakes. Norwidge soils are on mountain slopes and have fragic characteristics. Poorman and Scaler soils are on mountain slopes and ridge tops and have a thin volcanic ash mantle. Threebear soils are on mountain slopes and have a fragipan.
DRAINAGE AND PERMEABILITY: Well drained, rapid runoff, moderate permeability.
USE AND VEGETATION: These soils are used for timber production, wildlife habitat, watershed and recreation. Potential natural vegetation is western redcedar, Douglas fir, grand fir and western white pine with an understory of queencup beadlilly, goldthread, starry false Solomons seal, columbia brome and baldhip rose.
DISTRIBUTION AND EXTENT: North-Central Idaho; Scand soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Clearwater County, Idaho, 2003.
REMARKS: Diagnostic horizons and other features recognized in this pedon are:
Ochric epipedon - The zone from the mineral soil surface to 7 inches. (A and part of Bw horizon)
Cambic horizon - The zone from 4 to 16 inches. (Bw horizon)
Argillic horizon - The zone from 16 to 53 inches. (2Bt and 3Bt horizons)
Volcanic ash cap - The zone from the mineral soil surface to 16 inches. (A and Bw horizons)
Particle size control section - The zone from the mineral soil surface to 41 inches. (A, Bw, 2Bt1, 2Bt2, 3Bt3 and part of the 3Bt4 horizon)
The values listed under the Range In Characteristics for Bulk density, Volcanic glass, Acid-oxalate extractable Al+1/2Fe, Phosphorous retention and 15 bar water retention are estimates only.