LOCATION TAMARRON COEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Eutric Haplocryalfs
TYPICAL PEDON: Tamarron loam, on a northeast facing, simple, 35 percent slope in spruce-fir woodland at an elevation of 10,400 feet. (Colors are for dry soil unless otherwise noted.) Described on Sept. 23, 1985.
Oi--0 to 3 inches; organic mat of needles, leaves, and twigs. (1 to 3 inches thick)
E--3 to 9 inches; light brownish gray (10YR 6/2) loam, brown (10YR 5/3) moist; weak very fine granular structure; soft, very friable, nonsticky and nonplastic; 5 percent gravel; many fine and medium roots; few fine pores; slightly acid (pH 6.2); clear smooth boundary. (4 to 16 inches thick)
Bt1--9 to 20 inches; light brown (7.5YR 6/4) very channery clay loam; brown (7.5YR 5/4) moist; moderate fine subangular blocky structure parting to moderate medium granular; slightly hard, friable, slightly sticky and slightly plastic; 20 percent channers and 10 percent flagstones; few distinct clay films on faces of peds; many fine and medium roots; few fine pores; slightly acid (pH 6.4); clear smooth boundary.
Bt2--20 to 30 inches; pale brown (10YR 6/3) very flaggy loam; yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; 25 percent channers, 25 percent flagstones, 2 percent stones; few distinct clay films on faces of peds; many fine roots; few fine pores; slightly acid (pH 6.4); clear smooth boundary. (Combined thickness of the Bt horizons is 15 to 30 inches)
C--30 to 39 inches; pale brown (10YR 6/3) extremely flaggy loam; yellowish brown (10YR 5/4) moist; weak fine granular structure; soft, very friable, nonsticky and nonplastic; 40 percent channers, 40 percent flagstones, 2 percent stones; few fine roots; few fine pores; slightly acid (pH 6.2); gradual wavy boundary. (0 to 10 inches thick)
Cr--39 to 49 inches; weathered platy sandy shale.
TYPE LOCATION: La Plata County, Colorado, about 20 miles north of Durango, Colorado, on Missionary Ridge near Forest Service Road 682.; located about 3,000 feet north and 2,300 feet east of the southwest corner of Sec. 15, T. 37 N., R. 8 W.; Lemon Reservoir USGS quad.; lat. 37 degrees, 28 minutes, 25 seconds N.; and long. 107 degrees, 44 minutes, 07 seconds W., NAD 27
RANGE IN CHARACTERISTICS: (depths given are measured from the mineral soil surface)
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: 35 to 40 degrees F.
Mean summer soil temperature: 41 to 46 degrees F. with an O horizon.
Lithology of rock fragments: sandstone, shale
Base saturation: 70 to 90 percent
Depth to paralithic contact: 20 to 40 inches.
Particle-size control section:
Clay content: 18 to 35 percent
Rock fragment content: 35 to 65 percent.
E horizon:
Hue: 7.5YR or 10YR
Value: 6 or 7 dry, 4 or 5 moist
Chroma: 2 to 4, dry and moist
Reaction: moderately acid to neutral
Bt horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 to 6, dry and moist
Texture, fine earth fraction: L, CL, or SCL
Rock fragment content: 35 to 65 percent
Reaction: moderately acid to neutral
C horizon, if present:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 2 to 4, dry and moist
Texture, fine earth fraction: L
Rock fragment content: 35 to 85 percent
Reaction: moderately acid to neutral
COMPETING SERIES: These are the Frisco, Helmville, Needleton, Redondo, Tigeron, and Worock series. In addition, the following soils may be competitors when their classification is updated: Cadotte, Hardzem, Hyattville, Lake Creek, Macfarlane, and Tenrag series.
Hyattville and
Lake Creek: have a lithic contact at depths of 20 to 40 inches.
Cadotte,
Frisco,
Helmville,
Macfarlane,
Needleton,
Redondo,
Tenrag,
Tigeron, and Worock: do not have bedrock within 40 inches of the surface.
Hardzem: are slightly alkaline, and have mean annual soil temperature of 41 to 45 degrees F.
GEOGRAPHIC SETTING:
Parent material: slope alluvium and colluvium derived mostly from sandy shale and sandstone.
Landform: mountain slopes, ridges
Slopes: 15 to 60 percent
Elevation: 8,000 to 10,600 feet
Mean annual air temperature: 34 to 38 degrees F.
Mean annual precipitation: 30 to 45 inches.
Wettest months: July and August receive the most precipitation.
Driest months: May and June receive the least precipitation, however the soils are still wet from snowmelt.
Frost-free period: 40 to 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Frisco, Haviland, Needleton, and Snowdon series. All are on mountain slopes.
Frisco,
Haviland, and
Needleton soils do not have bedrock within 40 inches of the surface.
Snowdon soils have bedrock within 20 inches of the surface.
DRAINAGE AND PERMEABILITY: Well drained; low to medium runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for timber production, wildlife habitat, and livestock grazing. Principal native vegetation is Engelmann's spruce, subalpine fir, quaking aspen, snowberry, kinnikinnick, whortleberry, mountain brome, and needlegrass.
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 PROPOSED: La Plata County, Colorado, Animas-Dolores Soil Survey Area, 1985.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon and albic horizon: The zone from 3 to 9 inches. (E horizon)
Argillic horizon: The zone from 9 to 30 inches. (Bt1 and Bt2 horizons)
Paralithic contact: Weathered platy sandy shale at 39 inches. (Cr layer)
Particle size control section: The zone from 9 to 30 inches. (Bt1 and Bt2 horizons)
Series control section: The zone from 0 to 49 inches (all horizons and upper 10 inches of Cr layer)
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.
ADDITIONAL DATA: A similar soil was sampled by NSSL as Tamarron at a different location but lacked the clay increase for an argillic horizon and had many sandy shale fragments that may have been ground up into sand and silt sized particles. Sample No. S86-CO-067-004.