LOCATION MAUDREY COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Pachic Paleustolls
TYPICAL PEDON: Maudrey loam, on a southeast facing, simple, 3 percent slope in ponderosa pine woodland at an elevation of 8720 feet. (Colors are for dry soil unless otherwise noted). Described on September 10, 1985.
A1--0 to 4 inches; dark brown (10YR 3/3) loam, black (10YR 2/1) moist; weak fine subangular blocky structure parting to weak very fine granular; soft, very friable, nonsticky and slightly plastic; many very fine and fine roots; many very fine continuous pores; 5 percent gravel; slightly acid (pH 6.5); clear smooth boundary.
A2--4 to 11 inches; brown (10YR 4/3) loam, black (10YR 2/1) moist; moderate medium subangular blocky structure parting to moderate fine subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine continuous pores; 5 percent gravel, slightly acid (pH 6.5); clear wavy boundary.
A3--11 to 19 inches; brown (10YR 4/3) loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine continuous pores; 5 percent gravel, slightly acid (pH 6.5); clear wavy boundary. (Combined thickness of the A horizons is 18 to 32 inches)
AB--19 to 25 inches; yellowish brown (10YR 5/4) loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine continuous pores; 5 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (0 to 8 inches thick)
EBt--25 to 31 inches; very pale brown (10YR 7/4) loam, dark yellowish brown (10YR 4/6) moist; weak fine subangular blocky structure parting to weak fine granular; slightly hard, friable, slightly sticky and moderately plastic; few very fine and fine roots; many very fine continuous pores; few faint clay films on faces of peds; 10 percent gravel; moderately acid (pH 5.8); gradual wavy boundary. (0 to 10 inches thick)
Bt1--31 to 41 inches; strong brown (7.5YR 4/6) clay loam, strong brown (7.5YR 5/6) moist; weak medium prismatic structure parting to strong medium subangular blocky; hard, firm, moderately sticky and moderately plastic; few fine and very fine roots; many very fine continuous pores; many prominent clay films on faces of peds; 10 percent gravel; very strongly acid (pH 4.8); clear wavy boundary.
Bt2--41 to 54 inches; strong brown (7.5YR 5/6) clay, strong brown (7.5YR 5/6) moist; moderate medium prismatic structure parting to strong medium subangular blocky; very hard, extremely firm, very sticky and moderately plastic; common very fine continuous pores; many prominent clay films on faces of peds; 10 percent gravel; very strongly acid (pH 4.8); clear wavy boundary. (Combined thickness of the Bt horizons is 14 to 30 inches)
C--54 to 60 inches; yellowish brown (10YR 5/6) clay, yellowish brown (10YR 5/6) moist; massive; very hard; very firm, very sticky and moderately plastic; few very fine continuous pores; 14 percent gravel; very strongly acid (pH 4.8).
TYPE LOCATION: Dolores County, Colorado; about 13 miles north of Mancos; located about 250 feet west and l,300 feet south of the northeast corner, sec. 28, T. 38 N., R. 13 W.; Stoner USGS Quad; lat. 37 degrees, 31 minutes, 42 seconds N. and long. 108 degrees, 17 minutes, 06 seconds W. NAD 27
RANGE IN CHARACTERISTICS:
Soil moisture regime: ustic (typic ustic subclass).
Mean annual soil temperature: 42 to 45 degrees F.
Mean summer soil temperature: 60 to 63 degrees F.
Thickness of the mollic epipedon: 20 to 40 inches
Depth to the top of the argillic horizon: 25 to 40 inches.
Particle-size control section:
Clay content: 35 to 55 percent
Rock fragment content: 0 to 15 percent
A horizon:
Hue: 7.5YR or 10YR
Value: 3 to 4 dry, 2 or 3 moist
Chroma: 1 to 3, dry and moist (some subhorizons may have dry chroma of 4)
Rock fragment content: 0 to 10 percent
Reaction: moderately acid or slightly acid
EBt horizon: (when present)
Hue: 7.5YR or 10YR
Value: 4 to 7 dry, 3 or 4 moist
Chroma: 2 to 6, dry and moist
Rock fragment content: 0 to 10 percent
Reaction: moderately acid or slightly acid
Bt horizon:
Value: 4 to 6 dry, 4 or 5 moist
Chroma: 5 or 6, dry and moist
Texture: C, CL
Rock fragments: 0 to 15 percent
Base saturation: 50 to 70 percent (estimated)
Reaction: very strongly acid or strongly acid
C horizon: (not in all pedons)
Hue: 7.5YR or 10YR
Value: 5 to 7 dry, 5 or 6 moist
Chroma: 3 to 6, dry and moist
Texture: C, CL
Rock fragment content: 5 to 20 percent
Base saturation: 50 to 70 percent (estimated)
Reaction: very strongly acid or strongly acid
COMPETING SERIES: This is the
Kinesava series. A former competitor is the
Maughan series which now is a Palexerolls.
Kinesava soils: have neutral to moderately alkaline reaction throughout.
GEOGRAPHIC SETTING:
Parent material: slope alluvium derived from Dakota sandstone.
Landform: mesas.
Slopes: 1 to 15 percent
Elevation: 8,200 to 8,900 feet
Mean annual air temperature: 40 to 42 degrees F.
Mean annual precipitation: 20 to 25 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: 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Behanco,
Fughes, and Tombac soils.
Behanco soils have a cryic temperature regime and are on mesas at higher elevations.
Fughes soils have the top of the argillic horizon above 24 inches and are in drainageways and on hills.
Tombac soils do not have the thick mollic epipedon and are on mesas.
DRAINAGE AND PERMEABILITY: Well drained; low runoff; moderate permeability in the upper part of the profile and slow permeability in the lower part.
USE AND VEGETATION: These soils are used for timber production, livestock grazing, and wildlife habitat. The native vegetation is ponderosa pine, Gamble's oak, mountain snowberry, quaking aspen, serviceberry, Parry's danthonia, bluegrass, bromegrass, and western wheatgrass.
DISTRIBUTION AND EXTENT: Southwestern Colorado. LRR E, MLRA 48A. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Dolores County, Animas-Dolores Area. Colorado. 1997
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon (Pachic feature): the zone from the 0 to 25 inches (A1, A2, A3, and AB horizons).
Argillic horizon: the zone from 31 to 54 inches (Bt1 and Bt2 horizons).
Pale feature: The argillic horizon has hue of 7.5YR and chroma of 5 or more.
Particle size control section: The zone from 31 to 51 inches (Bt1 horizon and part of the Bt2 horizon).
Keys to Soil Taxonomy: Classified according to the Eighth Edition, 1998