LOCATION CARIBOURIDGE IDEstablished Series
TAXONOMIC CLASS: Ashy over sandy or sandy-skeletal, glassy over mixed, frigid Typic Udivitrands
TYPICAL PEDON: Caribouridge ashy silt loam, forest; on a northeast-facing slope of 34 percent at 3,100 feet elevation. When described on July 12, 1995, the soil was moist throughout. (Colors are for dry soil unless otherwise stated.)
0i--0 to 1 inch; needles, leaves, twigs, bark, and cones. (0.5 to 1.5 inches thick)
0e--1 to 2 inches; decomposed organic matter mixed with Mt. St. Helens volcanic ash. (0.5 to 1.5 inches thick)
A--2 to 3 inches; grayish brown (10YR 5/2) ashy silt loam, very dark grayish brown (10YR 3/2) moist; weak very fine granular structure; soft, very friable, nonsticky and slightly plastic; many very fine, few fine and medium roots; many very fine tubular pores; slightly acid (pH 6.5); abrupt wavy boundary. (1 to 2 inches thick)
Bw1--3 to 9 inches; yellowish brown (10YR 5/4) ashy silt loam, dark yellowish brown (10YR 3/4) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and slightly plastic; many very fine, few fine, medium and coarse roots; many very fine and few fine tubular pores; 5 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (5 to 8 inches thick)
Bw2--9 to 18 inches; light yellowish brown (10YR 6/4) ashy silt loam, dark yellowish brown (10YR 4/4) moist; weak medium and coarse subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common very fine, few fine, medium and coarse roots; many very fine and few fine tubular pores; 5 percent gravel; slightly acid (pH 6.5); abrupt wavy boundary. (8 to 10 inches thick)
2BC--18 to 23 inches; pale yellow (2.5Y 7/4) very cobbly loamy coarse sand, light olive brown (2.5Y 5/4) moist; weak fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine, few fine and medium roots; common very fine and few fine tubular and irregular pores; few very fine mica flakes; 20 percent gravel, 35 percent cobbles; slightly acid (pH 6.4); gradual wavy boundary. (0 to 9 inches thick)
2C1--23 to 44 inches; pale yellow (2.5Y 7/4) extremely cobbly coarse sand, light olive brown (2.5Y 5/4) moist; single grain; loose, nonsticky and nonplastic; few fine and medium roots; many very fine and fine irregular pores; few very fine mica flakes; 35 percent gravel, 40 percent cobbles; slightly acid (pH 6.4); gradual wavy boundary. (12 to 21 inches thick)
2C2--44 to 60 inches; light yellowish brown (2.5Y 6/4) extremely cobbly coarse sand, olive brown (2.5Y 4/4) moist; single grain; loose, nonsticky and nonplastic; few fine and medium roots; many very fine and fine irregular pores; few very fine mica flakes; 25 percent gravel, 40 percent cobbles, and 5 percent stones; slightly acid (pH 6.4).
TYPE LOCATION: Boundary County, Idaho; about 4.25 miles west of Naples; about 2,000 feet south and 800 feet west of the northeast corner of sec. 8, T. 60 N., R. 1 W.;
Latitude - 48 degrees, 34 minutes, 15 seconds North;
Longitude - 116 degrees, 28 minutes, 59 seconds West.
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 - 15 to 24 inches.
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.
A horizon
Value - 4 or 5 dry, 2 or 3 moist
Texture - ASHY-SIL, ASHY-L, GR-ASHY-SIL
Clay content - 3 to 8 percent
Gravel content - 0 to 30 percent
Bulk density - 0.65 to 0.90 g/cc
Reaction - strongly acid to slightly acid
Bw horizons
Value - 5 or 6 dry, 3 or 4 moist
Texture - ASHY-SIL, ASHY-L, GR-ASHY-SIL, CB-ASHY-SIL
Clay content - 3 to 8 percent
Gravel content - 0 to 25 percent
Cobble content - 0 to 15 percent
Bulk density - 0.65 to 0.90 g/cc
Reaction - slightly acid to neutral
2BC horizon
Hue - 2.5Y or 10YR
Value - 6 or 7 dry, 4 or 5 moist
Texture - CBV-LCOS, GRV-LS, GRV-SL
Clay content - 2 to 8 percent
Gravel content - 15 to 35 percent
Cobble content - 0 to 35 percent
Mica content - 0 to 20 percent
Reaction - slightly acid to neutral
2C horizons
Hue - 2.5Y, 10YR, or variegated
Value - 6 or 7 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Texture - CBX-COS, GRX-COS, GRV-COS, GRV-LS, CBV-LS
Clay content - 0 to 3 percent
Gravel content - 15 to 45 percent
Cobble content - 5 to 40 percent
Stone content - 0 to 5 percent
Mica content - 0 to 20 percent
Reaction - moderately acid to neutral
COMPETING SERIES: This is the St. Helens series. St. Helens soils have sandy loam and loamy sand Bw horizons and contain pumice fragments.
GEOGRAPHIC SETTING: Caribouridge soils are on mountains, foothills, and footslopes. Slopes range from 0 to 65 percent. They formed in glacial till and outwash derived from granite and gneiss rocks, with a thick mantle of volcanic ash. Elevations range from 2,400 to 5,000 feet. The average annual air temperature ranges from 42 to 45 degrees F. and average annual precipitation ranges from 30 to 50 inches. The average frost-free period is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dodgecreek (T), Idamont, Myrtlecreek (T), Pend Oreille, Redraven, Roman (T), and Rubycreek (T). Dodgecreek and Myrtlecreek soils are on dissected outwash terraces and contain less volcanic ash and less than 35 percent rock fragments. Idamont and Pend Oreille soils are on mountains and foothills and are ashy over loamy. Redraven, Roman, and Rubycreek soils are on mountains at higher elevations and are cryic.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability in the upper part and rapid to very rapid below.
USE AND VEGETATION: These soils are used for timber production, wildlife habitat, recreation, and watershed. Natural vegetation is mainly western hemlock, western redcedar, grand fir, Douglas-fir, western larch, western white pine, ponderosa pine, lodgepole pine, and birch with an understory of dampwoods blueberry, queencup beadlily, pyrola, western rattlesnake plantain, common princes pine, western wintergreen, Utah honeysuckle, darkwoods violet, heartleaf arnica, myrtle pachystima, and common beargrass.
DISTRIBUTION AND EXTENT: Northern Idaho, and possibly northwestern Montana and northeastern Washington. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Boundary County, Idaho, 2002.
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 horizon)
Cambic horizon - the zone from 3 to 18 inches (Bw1 and Bw2 horizons)
Volcanic ash mantle - the zone from 2 to 18 inches (A, Bw1, and Bw2 horizons)
Particle-size control section - the zone from 2 to 42 inches (A, Bw1, Bw2, 2BC and part of the 2C1 horizon)