LOCATION WANDER COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Typic Argicryolls
TYPICAL PEDON: Wander very cobbly loam, on an east facing, simple, 50 percent slope in grassland, at an elevation of 10,600 feet. (Colors are for dry soil unless otherwise noted.) Described on October 5, 1988.
A--0 to 14 inches; dark grayish brown (10YR 4/2) very cobbly loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, very friable, nonsticky and nonplastic; many fine and very fine roots, many fine pores; 15 percent gravel, 15 percent cobble, 10 percent stones; slightly acid (pH 6.1); gradual smooth boundary. (10 to 16 inches thick)
Bt1--14 to 27 inches; brown (7.5YR 5/3) very cobbly clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; few distinct clay films on faces of peds; few fine and very fine roots; few fine pores; 15 percent gravel, 20 percent cobbles, 10 percent stones; slightly acid (pH 6.2); gradual wavy boundary.
Bt2--27 to 40 inches; brown (7.5YR 5/3) very cobbly clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few faint clay films on faces of peds; few fine roots; 15 percent gravel, 25 percent cobbles, 10 percent stones; slightly acid (pH 6.2); gradual wavy boundary. (combined thickness of the Bt horizons is 15 to 40 inches)
C--40 to 60 inches; light brown (7.5YR 6/3) and reddish brown (5YR 5/3) very cobbly clay loam, and brown (7.5YR 4/3) and dark reddish gray (5YR 4/2) moist; mixed materials due to variable parent materials; massive; hard, firm, moderately sticky and moderately plastic; 15 percent gravel, 25 percent cobbles, 15 percent stones; slightly acid (pH 6.3).
TYPE LOCATION: La Plata County, Colorado; about 30 miles northwest of Durango, Colorado; located approximately 750 feet south and 1,300 feet west of the northeast corner of Sec. 31, T. 39 N., R. 10 W.; Orphan Butte USGS quad; lat. about 37 degrees 36 minutes 35 seconds N. and long. about 108 degrees 00 minutes 06 seconds W., NAD 27
RANGE IN CHARACTERISTICS:
Soil moisture regime: udic; dry in some part of the moisture control section for less than 45 cumulative days (typic udic subclass).
Mean annual soil temperature: 34 to 40 degrees F.
Mean summer soil temperature: 50 to 55 degrees F.
Thickness of the mollic epipedon: 10 to 16 inches
Lithology of rock fragments: sandstone
Particle-size control section:
Clay content: 20 to 35 percent.
Rock fragment content: 35 to 80 percent gravel, cobble, and stones
A horizon:
Hue: 7.5YR or 10YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 to 3, dry and moist
Rock Fragment content: 35 to 60 percent.
Reaction: moderately acid to neutral
Bt horizon:
Hue: 5YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 6, dry and moist
Texture, fine earth fraction: SCL, CL, L
Rock fragment content: 35 to 80 percent
Reaction: moderately acid to neutral
C horizon:
Hue: 5YR to 10YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 6, dry and moist
Texture, fine earth fraction: SCL, L, CL
Rock fragment content: 35 to 65 percent
Reaction: moderately acid to neutral
COMPETING SERIES: These are the Elwood and Quazar series. In addition, the following soils may be competitors when their classification is updated: Ess, Fourme, Latigo, Nathrop, and Stopatoe series.
Elwood and Nathrop: have a lithic contact at depths of less than 40 inches.
Ess: have volcanic ash, and cinders.
Fourme: have sandy-skeletal substratum above a depth of 40 inches.
Latigo: have horizons of calcium carbonate accumulation above 40 inches.
Quazar: have rock fragments derived from volcanic sources.
Stopatoe: has a paralithic contact at 40 to 60 inches.
GEOGRAPHIC SETTING:
Parent material: colluvium and slope alluvium derived from sandstone and shale.
Landform: mountain slopes and structural benches.
Slopes: 15 to 60 percent
Elevation: 8,000 to 11,500 feet
Mean annual air temperature: 32 to 38 degrees F.
Mean annual precipitation: 30 to 45 inches.
Wettest months: July and August receive slightly more precipitation than other months.
Driest months: May and June receive the least precipitation, however the soils are still moist from snowmelt.
Frost-free period: 40 to 75 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Hourglass,
Needleton, and
Scotch series. All are on mountain slopes.
Needleton soils do not have a mollic epipedon.
Hourglass soils are fine-loamy.
Scotch soils are shallow over sandstone bedrock.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff, moderately slow permeability.
USE AND VEGETATION: These soils are used principally as grazing land, wildlife habitat, and some aspen woodland. Native vegetation consists of Thurber fescue, mountain brome, needlegrass, prairie junegrass, American vetch, and quaking aspen.
DISTRIBUTION AND EXTENT: Mountain areas of southwestern Colorado. LRR E, MLRA 48A. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: La Plata County, Animas-Dolores Area, Colorado; 2002. Series proposed in 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: The zone from 0 to 14 inches. (A horizon)
Argillic horizon: The zone from 14 to 40 inches. (Bt1 and Bt2 horizons)
Particle-size control section: The zone from 14 to 34 inches. (Bt1 and part of the Bt2 horizons)
Keys to Soil Taxonomy: Classified according to Eighth Edition, 1998.
Activity class presumed based on general trend of soils in the area.