LOCATION MCCROSKET IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, mesic Ultic Haploxerolls
TYPICAL PEDON: McCrosket gravelly silt loam, woodland. (Colors are for dry soil unless otherwise noted.)
Oi--0 to 2 inches; partially decomposed duff, needles, etc. (0 to 2 inches thick)
A1--2 to 7 inches; dark grayish brown (10YR 4/2) gravelly silt loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine irregular and tubular pores; about 30 percent gravel; neutral (pH 6.8); abrupt smooth boundary.
A2--7 to 13 inches; brown (10YR 5/3) gravelly silt loam, dark brown (10YR 3/3) moist; moderate medium granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common very fine and fine tubular and irregular pores; about 30 percent gravel; neutral (pH 6.8); clear wavy boundary. (A horizons 5 to 20 inches thick)
Bw1--13 to 20 inches; light yellowish brown (10YR 6/4) very gravelly silt loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common fine and few medium roots; common very fine, fine and few medium tubular and irregular pores; about 60 percent gravel; moderately acid (pH 6.0); gradual wavy boundary.
Bw2--20 to 31 inches; light yellowish brown (10YR 6/4) very gravelly silt loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure parting to weak fine granular; slightly hard, very friable, slightly sticky and slightly plastic; few fine irregular and tubular pores; 75 percent gravel and stones; moderately acid (pH 6.0); clear wavy boundary.
Bw3--31 to 44 inches; very pale brown (10YR 7/4) very stony silt loam, yellowish brown (10YR 5/6) moist; weak medium and fine subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine and medium roots; many very fine tubular and irregular pores; 75 percent gravel and stones; moderately acid (pH 6.0); clear wavy boundary. (Bw horizons 23 to 33 inches thick)
Cr--44 inches; fractured metasedimentary rock with few fines in fractures.
TYPE LOCATION: Benewah County, Idaho; about 1 mile northeast of Moses Mountain on a 55 percent north slope; near the SE corner of the NE1/4 NW1/4 sec. 11 T.44N., R.4W. Latitude - 47 degrees, 10 minutes, 28 seconds North; Longitude - 116 degrees, 48 minutes, 00 seconds; USGS Benewah quadrangle.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 47 to 54 degrees F.
Average summer soil temperature - 59 to 63 degrees F. without an O horizon. (mesic temperature regime)
Mollic epipedon thickness - 10 to 17 inches.
Depth to fractured bedrock - 40 to 60 inches
Depth to consolidated bedrock - greater than 60 inches
Reaction - neutral to moderately acid.
These soils are dry in the moisture control section for 45 to 60 days in late July through mid September. (xeric moisture regime)
A horizons
Hue - 10YR or 7.5YR dry and moist
Value - 3 to 5 dry, 2 to 4 moist
Chroma - 1 to 4 dry, 1 to 3 moist
Texture - L, SIL, GR-L, GR-SIL
Clay content - 8 to 18 percent
Rock fragments - 5 to 25 percent gravel, 0 to 5 percent cobbles, 5 to 25 percent total fragments
Reaction - moderately acid to neutral
Bw horizons
Hue - 5YR to 10YR dry or moist
Value - 4 to 7 dry, 3 to 6 moist
Chroma - 2 to 6 dry or moist
Textures - GRV-SIL, GRV-L, CB-L, CBV-L, CBX-L, ST-SIL, ST-L, GR-L, GRV-SL, GR-SIL
Clay content - 12 to 25 percent
Rock fragments - 15 to 45 percent gravel; 0 to 50 percent cobbles; 0 to 15 percent stones; 25 to 80 percent total fragments
Reaction - very strongly acid to slightly acid
C and BC horizons (when present)
Hue - 7.5YR to 10YR dry or moist
Value - 6 to 8 dry, 4 to 7 moist
Chroma - 4 to 6 dry or moist
Texture - CBV-SL, GRX-L, GRV-SL
Clay content - 5 to 26 percent
Rock fragments - 30 to 50 percent gravel, 2 to 25 percent cobbles, 0 to 5 percent stones, 40 to 60 percent total fragments
Reaction - very strongly acid to moderately acid
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: McCrosket soils are on mountain slopes at elevations of 1,600 to 4,000 feet. Slopes range from 5 percent to about 65 percent with slopes of 30 to 40 percent being dominant. The average annual precipitation ranges from 24 to 35 inches. The average annual air temperature ranges from 45 to 52 degrees F. The frost-free period ranges from 90 to 180 days (9 in 10 years to 1 in 10 years, respectively). McCrosket soils formed from metasediments of the Belt series, with some influence from loess in the surface. At the lower elevations, they are on northerly slopes and at higher elevations, they are on southerly slopes and ridgetops.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ardenvoir, Pedee, and Tekoa soils. Ardenvoir soils have light-colored A1 horizons and are on mountains. Pedee soils have an argillic horizon and are on terraces. Tekoa soils have an argillic horizon
DRAINAGE AND PERMEABILITY: Well-drained; medium to very rapid runoff; moderate permeability.
USE AND VEGETATION: Used mainly for timber production with limited grazing. Some cleared areas are used for pasture. Native vegetation is Douglas-fir, ponderosa pine, common snowberry, birchleaf spirea, rose species, and pinegrass.
DISTRIBUTION AND EXTENT: Northern Idaho and eastern Washington. The series is moderately extensive.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Benewah County, Idaho, 1975.
REMARKS: Diagnostic horizons and other features recognized in this pedon:
Mollic epipedon - The zone from 2 to 13 inches (A horizons).
Cambic horizon - The zone from 13 to 44 inches (B horizons).
Particle-size control section - The zone from 10 to 40 inches (a portion of A2 horizon, BW1, Bw2 horizons, and a portion of Bw3 horizon).