LOCATION DRESSEL COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Pachic Haplocryolls
TYPICAL PEDON: Dressel gravelly loam, on a southeast facing, simple, 45 percent slope in aspen woodland at an elevation of 9,615 feet. (Colors are for dry soil unless otherwise noted.) Described on August 6, 1985.
Oe--0 to 2 inches; organic layer of moderately decomposed leaves and twigs. (1 to 3 inches thick)
A1--2 to 8 inches; very dark grayish brown (10YR 3/2) gravelly loam, black (10YR 2/1) moist; weak very fine granular structure; soft, very friable, nonsticky and slightly plastic; many very fine and fine, and few medium roots; many very fine continuous pores; 15 percent gravel, 5 percent cobble, 5 percent stones; neutral (pH 6.8); clear smooth boundary. (6 to 16 inches thick)
A2--8 to 19 inches; very dark grayish brown (10YR 3/2) very stony loam, black (10YR 2/1) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine, and few medium roots; many very fine discontinuous pores; 10 percent gravel, 20 percent cobble, 25 percent stones; neutral (pH 6.6); clear wavy boundary. (6 to 14 inches thick)
E--19 to 23 inches; light gray (10YR 7/2) very cobbly sandy clay loam, yellowish brown (10YR 5/4) moist; common fine faint yellowish brown (10YR 5/6) lithochromic mottles; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and moderately plastic; few very fine, fine, and coarse roots; many very fine discontinuous pores; 10 percent gravel, 35 percent cobble, 10 percent stones; neutral (pH 6.6); clear wavy boundary. (0 to 5 inches thick)
Bw1--23 to 30 inches; light brownish gray (10YR 6/2) very cobbly sandy clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; very hard, friable, slightly sticky and moderately plastic; few very fine, fine, medium, and coarse roots; many very fine discontinuous pores; 10 percent gravel, 30 percent cobble, 15 percent stones; neutral (pH 6.8); clear wavy boundary.
Bw2--30 to 36 inches; light brownish gray (10YR 6/2) extremely cobbly loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and moderately plastic; few very fine, fine, medium, and coarse roots; many very fine discontinuous pores; 15 percent gravel, 40 percent cobble, 15 percent stones; neutral (pH 6.8); clear wavy boundary.
Bw3--36 to 45 inches; light gray (10YR 7/2) extremely cobbly loam, brown (10YR 4/3) moist; common fine distinct yellowish brown (10YR 5/6) lithochromic mottles; moderate medium subangular blocky structure parting to moderate fine subangular blocky; hard, friable, nonsticky and slightly plastic; few very fine, fine, and medium roots; many very fine discontinuous pores; 15 percent gravel, 45 percent cobble, 10 percent stones; neutral (pH 6.8). (combined thickness of the Bw horizons is 20 to 30 inches)
C1--45 to 53 inches; light gray (10YR 7/1) extremely cobbly loam, dark grayish brown (10YR 4/2) moist; few fine faint yellowish brown (10YR 5/6) lithochromic mottles; massive; hard, firm, slightly sticky and moderately plastic; few fine roots; common very fine discontinuous pores; 20 percent gravel, 35 percent cobble, 15 percent stones; neutral (pH 6.6); gradual wavy boundary. (6 to 24 inches thick)
C2--53 to 61 inches; light brownish gray (10YR 6/2) very cobbly loam, grayish brown (10YR 5/2) moist; few fine faint brownish yellow (10YR 6/6) lithochromic mottles; massive; hard, firm, moderately sticky and moderately plastic; 10 percent gravel, 30 percent cobble, 15 percent stones; neutral (pH 6.8).
TYPE LOCATION: Montezuma County, Colorado; about 6 miles north of Stoner; located about 1,400 feet north and 2,500 feet west of the southeast corner of sec. 20, T. 39N., R. 12W.; Wallace Ranch USGS quad; lat. 37 degrees 37 minutes 23 seconds N.; long. 108 degrees 12 minutes 09 seconds W., NAD 27
RANGE IN CHARACTERISTICS: (Depths given are measured from the mineral surface)
Soil moisture regime: udic
Mean annual soil temperature: 36 to 40 degrees F.
Mean summer soil temperature: 43 to 47 degrees F. with an O horizon
Surface rock fragments: 0 to 3 percent stones, sandstone fragments
Thickness of the mollic epipedon: 16 to 30 inches
Particle-size control section:
Clay content: 20 to 30 percent
Rock fragment content: 35 to 70 percent sandstone fragments
A horizon:
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 or 2, dry and moist
Rock fragment content: 15 to 60 percent
Reaction: slightly acid or neutral
E horizon: (not present in all pedons)
Value: 6 or 7 dry, 5 or 6 moist
Chroma: 2 to 4, dry and moist
Rock fragment content: 15 to 65 percent, mostly cobble
Reaction: slightly acid or neutral
Bw horizon (a Bt in some pedons):
--- some pedons have few faint clay films but lacks clay increase for an argillic horizon.
Value: 5 to 7 dry, 4 or 5 moist
Chroma: 2 to 4, dry and moist
Texture, fine earth fraction: L, CL, SCL
Rock fragment content: 35 to 70 percent, mostly cobble
Reaction: slightly acid or neutral
C horizon:
Hue: 10YR or 2.5Y
Value: 6 or 7 dry, 2 to 4 moist
Chroma: 2 to 4, dry and moist
Texture, fine earth fraction: L, CL
Rock fragment content: 35 to 75 percent, mostly cobble
COMPETING SERIES: These are the Baconcamp, Behanco, Behanin, Belsac, Blanca, Busterback, Caballo, Campone, Croesus, Darland, Gateview, Hapgood, Harcany, Hobacker, Lionhead, Lolon, Marcetta, Nagitsy, Namela, Nazaton, Nevtah, Papaspila, Parkcity, Poleline, Povey, Prong, Snag, Snopoc, Splitbutte, and Tonigut series.
Baconcamp: have a lithic contact of granite at 20 to 40 inches.
Behanco: have lithic contact at 40 to 60 inches from the mineral surface.
Behanin and Papaspila: have rock fragments of volcanic rocks.
Belsac,
Croesus,
Hapgood,
Nagitsy,
Namela,
Nevtah,
Prong, and Splitbutte: have a lithic contact at depths of 20 to 40 inches.
Blanca,
Busterback,
Darland,
Gateview,
Harcany,
Parkcity,
Poleline,
Povey,
Snag, and Snopoc: have less than 18 percent clay in the particle-size control section.
Caballo,
Hobacker,
Lionhead, and Tonigut: have horizons of calcium carbonate accumulation.
Campone: do not have cambic horizons and have redoximorphic features and endosaturation.
Lolon: have discontinuity of loose sand, gravel and cobbles.
Marcetta: have a presumed ustic moisture regime.
Nazaton: have a mean annual soil temperature above 42 degrees F.
GEOGRAPHIC SETTING:
Parent material: Colluvium and slope alluvium derived from interbedded sandstone and shale.
Landform: mountain slopes and canyon sideslopes.
Slopes: 30 to 80 percent
Elevation: 7,600 to 10,500 feet
Mean annual air temperature: 34 to 40 degrees F.
Mean annual precipitation: 25 to 35 inches.
Wettest months: July and August.
Driest months: May and June receive the least precipitation, however the soils are still moist from snowmelt.
Frost-free period: 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Behanco, Haycamp, and Jersey series.
Behanco soils have a lithic contact at 40 to 60 inches.
Haycamp soils do not have a mollic epipedon.
Jersey soils do not have a thick mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained, medium to high runoff, moderate permeability.
USE AND VEGETATION: Dressel soils are used for timber production, livestock grazing, and wildlife habitat. The native vegetation consists of aspen, snowberry, woods rose, nodding brome, Columbia needlegrass, bearded wheatgrass, Thurber fescue, fern, Richardson geranium, cowparsnip, and meadow rue.
DISTRIBUTION AND EXTENT: Southwestern Colorado. LRR E, MLRA 48A. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Montezuma County, Animas-Dolores Soil Survey Area, Colorado, 2002. Series proposed in 1997. The name is taken from a reservoir of the same name.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon, (Pachic feature): The zone from 2 to 19 inches. (A1 and A2 horizons)
Albic horizon: The zone from 19 to 23 inches. (E horizon)
Cambic horizon: The zone from 23 to 45 inches. (Bw horizons) Lacks clay increase for an argillic horizon.
Particle size control section: The zone from 12 to 42 inches. (part of the A2, the E, Bw1, Bw2, and part of the Bw3 horizon)
Keys to Soil Taxonomy: Classified according to the Eighth Edition, 1998
Activity class presumed from the general trend of other soils in the area.