LOCATION PRESNAL IDInactive Series
TAXONOMIC CLASS: Coarse-loamy, mixed, frigid Vitrandic
Eutrochrepts
TYPICAL PEDON: Presnal loam, forested, on a 50 percent slope at 2,200 feet elevation. Aspect is southwest.
A--0 to 4 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate very fine and fine subangular blocky structure; very hard, firm, slightly sticky and slightly plastic; many very fine, common fine and few medium and coarse roots; many very fine and common fine irregular and common very fine tubular pores; moderately acid (pH 6.0); clear wavy boundary. (2 to 7 inches thick)
BA--4 to 9 inches; pale brown (10YR 6/3) loam, dark yellowish brown (10YR 3/4) moist; moderate very fine and fine subangular blocky structure; hard, firm, slightly sticky and slightly plastic; many very fine, common fine and few medium and very coarse roots; many very fine and common fine irregular and common very fine tubular pores; few faint patchy clay films in pores; moderately acid (pH 6.0); abrupt wavy boundary. (0 to 9 inches thick)
Bt1--9 to 17 inches; very pale brown (10YR 7/3) loam, yellowish brown (10YR 5/4) moist; weak medium and coarse prismatic structure parting to moderate medium and coarse subangular blocky; very hard, firm, slightly sticky and slightly plastic; common very fine and few fine, medium and very coarse roots; common very fine irregular and many very fine and common fine tubular pores; common faint discontinuous clay films in pores and on faces of peds; one percent fine mica flakes; moderately acid (pH 6.0); clear wavy boundary.
Bt2--17 to 24 inches; very pale brown (10YR 7/4) loam, light yellowish brown (10YR 6/4) moist; moderate fine, medium and coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine and few fine, medium, coarse and very coarse roots; common very fine irregular and many very fine and common fine tubular pores; few faint patchy clay films in pores; one percent fine mica flakes; moderately acid (pH 6.0); gradual wavy boundary. (Combined thickness of Bt horizons is 11 to 34 inches.)
BC--24 to 35 inches; very pale brown (10YR 8/4) sandy loam, very pale brown (10YR 7/4) moist; weak medium and coarse subangular blocky structure; hard, friable, slightly sticky and nonplastic; common very fine and few fine, medium, coarse and very coarse roots; many very fine, common fine and few medium tubular pores; one to five millimeter thick clay bands spaced two to five inches apart; 2 percent fine mica flakes; moderately acid (pH 5.8); gradual wavy boundary. (0 to 11 inches thick)
C1--35 to 43 inches; 60 percent very pale brown (10YR 8/3) loam, very pale brown (10YR 7/3) moist; 40 percent very pale brown (10YR 7/3) loam, light yellowish brown (10YR 6/4) moist; weak fine, medium and coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and few fine, medium, coarse and very coarse roots; common very fine irregular and common very fine and fine tubular pores; one 2 to 4 millimeter thick clay band; 2 percent fine mica flakes; moderately acid (pH 5.7); clear wavy boundary.
C2--43 to 51 inches; very pale brown (10YR 8/3) sandy loam, very pale brown (10YR 7/4) moist; massive; slightly hard, very friable, slightly sticky and non plastic; common very fine and few fine, medium, coarse and very coarse roots; common very fine irregular and common very fine and fine tubular pores; few faint patchy clay films between sand grains; 3 percent fine mica flakes; moderately acid (pH 5.6); abrupt wavy boundary.
C3--51 to 63 inches; 85 percent brownish yellow (10YR 6/6) coarse sandy loam, yellowish brown (10YR 6/6) moist; 15 percent very pale brown (10YR 8/3) coarse sandy loam, very pale brown (10YR 7/3) moist; massive; hard, friable, slightly sticky and slightly plastic; many very fine few fine and medium and common coarse and very coarse roots; common very fine irregular pores; many faint continuous clay films in cracks; 3 percent fine mica flakes; strongly acid (pH 5.4).
TYPE LOCATION: Clearwater County, Idaho; about 7 miles north and 13 miles east of Elk River, Idaho; about 750 feet south and 250 feet west of the northeast corner of Sec. 24, T41N, R4E; Latitude - 46 degrees, 53 minutes, 20 seconds North; Longitude - 115 degrees, 53 minutes, 26 seconds West; USGS Pinchot Butte Quadrangle.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 43 to 45 degrees F.
Soil moisture control section - not dry for 45 consecutive days from June to October.
Thickness of Vitrandic feature - 7 to 9 inches.
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Clay content - 12 to 16 percent
Rock fragments - 0 to 3 percent gravel
Bulk density - 1.00 to 1.15 g/cc
Volcanic glass - 5 to 15 percent
AO extractable Al+1/2Fe - 0.50 to 1.00 percent
BA horizon
Bulk density - 1.05 to 1.35 g/cc
Volcanic glass - 5 to 15 percent
AO extractable Al+1/2Fe - 0.40 to 1.00 percent
Bt horizons
Value - 5 to 7 dry, 3 to 6 moist
Chroma - 3 or 4 dry, 3 to 6 moist
Clay content - 15 to 20 percent
Rock fragments - 0 to 7 percent gravel
Bulk density in the upper part - 1.05 to 1.06 g/cc
Volcanic glass in the upper part - 0 to 15 percent
AO extractable Al+1/2Fe in the upper part - 0.10 to 1.00 percent
BC horizon
Value - 7 or 8 dry, 5 to 7 moist
Chroma - 3 or 4 dry, 4 to 6 moist
Texture - SL, GR-SL
Clay content - 12 to 19 percent
Rock fragments - 0 to 10 percent gravel, 0 to 5 percent cobbles, 0 to 15 percent total rock fragment content
C horizons
Value - 6 to 8 dry, 5 to 7 moist
Chroma - 3 to 6 dry or moist
Texture - L, SL, COSL, GR-SL
Clay content - 10 to 16 percent
Rock fragments - 0 to 10 percent gravel, 0 to 5 percent cobbles, 0 to 15 percent total rock fragment content
COMPETING SERIES: This is the Tamarack(T) series. Tamarack soils have horizons consisting of lamaellae.
GEOGRAPHIC SETTING: Presnal soils are on mountain slopes and ridgetops at elevations of 1,600 to 3,000 feet. They have slopes of 15 to 70 percent. These soils formed in material from anorthosite with a mantle of mixed volcanic ash. The average annual air temperature is 42 to 44 degrees F. The average annual precipitation is 40 to 45 inches. The frost free season is 80 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Floodwood, Keeler and Odonnell series. Floodwood soils are on mountain slopes and hills and have a thin mantle of unmixed volcanic ash. Keeler soils are on mountain slopes and hills and have an argillic horizon. Odonnell soils are on hills and have a glossic horizon.
DRAINAGE AND PERMEABILITY: Well drained, rapid to very 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, western hemlock, grand fir, western white pine and douglas fir with an understory of wild ginger, queencup beadlilly, goldthread, northern twinflower, darkwoods violet and oneleaf foamflower.
DISTRIBUTION AND EXTENT: North-Central Idaho; Presnal soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Clearwater County, Idaho 1996. The name is from a local spring.
REMARKS: Diagnostic horizons and other features recognized in this pedon are:
Ochric epipedon - The zone from the mineral soil surface to 9 inches. (A and BA horizons)
Cambic horizon - The zone from 4 to 35 inches. (BA, Bt1, Bt2 and BC horizons)
Vitrandic feature - The zone from the mineral soil surface to 9 inches. (A and BA horizons)
Particle size control section - The zone from 10 to 40 inches. (a part of the Bt1, Bt2, BC and a part of the C1 horizons)
The values listed in the Range In Characteristics for bulk density, volcanic glass and AO extractable Al+1/2Fe are estimates only.