LOCATION MAVREESO COEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Entic Haplustolls
TYPICAL PEDON: Mavreeso loam, on a south facing, simple, 22 percent slope in ponderosa pine woodland at an elevation of 7,920 feet. (Colors are for dry soil unless otherwise noted.)
A1--0 to 5 inches; reddish brown (5YR 4/3) loam, dark reddish brown (5YR 3/2) moist; weak medium subangular blocky structure parting to weak medium granular; slightly hard, friable, nonsticky and slightly plastic; many very fine and fine roots; many very fine pores; 5 percent channers; slightly alkaline (pH 7.4); clear wavy boundary. (3 to 15 inches thick)
A2--5 to 10 inches; reddish brown (5YR 4/3) loam, dark reddish brown (5YR 3/3) moist; weak medium subangular blocky structure parting to weak medium granular; slightly hard, friable, nonsticky and slightly plastic; many very fine and many fine roots; many very fine and common medium pores; slightly effervescent; 5 percent channers; slightly alkaline (pH 7.4); gradual wavy boundary. (0 to 12 inches thick)
Bw1--10 to 18 inches; yellowish red (5YR 4/6) loam, dark reddish brown (5YR 3/4) moist; weak coarse to weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and many medium roots; common very fine and few medium pores; slightly effervescent; 5 percent gravel; slightly alkaline (pH 7.6); gradual wavy boundary. (5 to 15 inches thick)
Bw2--18 to 28 inches; yellowish red (5YR 4/6) channery loam, reddish brown (5YR 4/4) moist; weak coarse subangular blocky structure; slightly hard, friable, nonsticky and slightly plastic; few very fine and common medium roots; common very fine and few medium pores; slightly effervescent; 20 percent channers; slightly alkaline (pH 7.6); clear wavy boundary. (0 to 25 inches thick)
Bk1--28 to 42 inches; yellowish red (5YR 4/6) loam, reddish brown (5YR 4/4) moist; moderate coarse subangular blocky structure parting to moderate medium subangular blocky; hard, friable, slightly sticky and slightly plastic; few very fine and common medium roots; common very fine and few medium pores; strongly effervescent; 5 percent channers; slightly alkaline (pH 7.8); clear wavy boundary. (10 to 20 inches thick)
Bk2--42 to 50 inches; yellowish red (5YR 5/6) channery loam, reddish brown (5YR 4/4) moist; massive; slightly hard, friable, nonsticky and slightly plastic; few medium roots; few very fine pores; few fine soft filaments of calcium carbonate; strongly effervescent; 30 percent channers; slightly alkaline (pH 7.8); clear wavy boundary. (0 to 15 inches thick)
Bk3--50 to 60 inches; yellowish red (5YR 5/6) loam, yellowish red (5YR 4/6) moist; massive; hard, friable, slightly sticky and slightly plastic; few medium roots; common very fine and few medium pores; few fine soft filaments of calcium carbonate; strongly effervescent; 5 percent gravel; moderately alkaline (pH 8.0).
TYPE LOCATION: Montezuma County, Colorado; approximately 20 miles northeast of the community of Dolores on the Taylor Mesa road; about 2,200 feet north and 1,470 feet east of the projected southwest corner of sec. 1, T. 38 N., R. 13 W.; Wallace Ranch USGS quad.; lat. 37 degrees, 34 minutes, 51 seconds north; longitude: 108 degrees, 14 minutes, 26 seconds west; NAD 27. (area not surveyed for range, township, and section).
RANGE IN CHARACTERISTICS:
Soil moisture regime: ustic; (typic ustic subclass). In most years the moisture control section is moist in some part 60 cumulative days when the soil temperature at 20 inches depth is above 41 degrees F.
Mean annual soil temperature: 44 to 47 degrees F.
Mean summer soil temperature: 59 to 63 degrees F.
Depth to secondary calcium carbonate: 26 to 40 inches
Thickness of the mollic epipedon: 7 to 16 inches
Lithology of rock fragments: sandstone
Particle-size control section (weighted averages):
Clay content: 18 to 27 percent
Rock fragment content: 15 to 35 percent
A horizon:
Hue: 2.5YR to 7.5YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3, dry and moist
Calcium carbonate equivalent: 0 to 2 percent
Reaction: slightly acid to slightly alkaline
Bw horizon:
Hue: 2.5YR to 7.5YR
Value: 3 to 6 dry, 3 to 5 moist
Chroma: 2 to 6, dry and moist
Texture, fine earth fraction: L, SL
Rock fragment content: 0 to 35 percent channers and gravel
Calcium carbonate equivalent: 1 to 2 percent
Reaction: neutral or slightly alkaline
Bk horizon:
Hue: 2.5YR to 7.5YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 3 to 6, dry and moist
Texture, fine earth fraction: L, SL
Rock fragment content: 0 to 35 percent channers and gravel
Calcium carbonate equivalent: 1 to 10 percent. If the clay percent is less than 18 percent, the calcium carbonate equivalent is less than 5 percent.
Reaction: moderately alkaline or slightly alkaline
COMPETING SERIES: These are the: Barvon, Coulterg, and Rottulee series.
In addition, soils that may be competitors when their classification is updated are the: Azaar, Minnimaud, and Roundup series.
Azaar,
Barvon,
Minnimaud,
Rottulee, and Roundup: have bedrock at a depth of 20 to 40 inches.
Coulterg: have hues 10YR or yellower.
GEOGRAPHIC SETTING:
Parent material: alluvium, slope alluvium, and colluvium derived from red sedimentary rocks.
Landform: fan remnants, canyon side slopes, and mountain slopes.
Slopes: 5 to 80 percent
Elevation: 7,100 to 8,500 feet
Mean annual air temperature: 43 to 46 degrees F.
Mean annual precipitation: 20 to 22 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: 75 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Needleton, Snowdon, and Valto series.
Needleton: have more than 35 percent rock fragments in the particle-size control section
Snowdon: have a lithic contact at 10 to 20 inches from the mineral soil surface.
Valto: soils have a lithic contact at a depth of 20 inches or less.
DRAINAGE AND PERMEABILITY: Well drained; medium or high runoff; moderate permeability.
USE AND VEGETATION: These soils are used for livestock grazing, wildlife habitat, and timber production. Native vegetation consists of ponderosa pine, Douglas-fir, Gambel oak, bluegrass, elk sedge, and fringed brome.
DISTRIBUTION AND EXTENT: Southwestern Colorado. LRR E, MLRA 48A. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Montezuma County (Animas-Dolores Soil Survey Area), Colorado, 1989.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: The zone from 0 to 10 inches. (A1 and A2 horizons)
Cambic horizon: The zone from 10 to 60 inches. (Bw and Bk horizons)
Particle-size control section: The zone from 10 to 40 inches. (Bw1, Bw2, and part of the Bk1 horizons)
Keys to Soil Taxonomy: Classified according to the Eighth Edition, 1998
Activity class is presumed based on general trend of other soils in the area.