LOCATION SKISAMS COEstablished Series
TAXONOMIC CLASS: Loamy, mixed, superactive Lithic Haplocryolls
TYPICAL PEDON: Skisams loam, in rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 4 inches; grayish brown (10YR 5/2) loam, very dark brown (10YR 2/2) moist; strong fine subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; 5 percent gravel; neutral; clear smooth boundary. (4 to 16 inches thick)
Bw--4 to 11 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; hard, very friable, nonsticky and nonplastic; 10 percent gravel; neutral; abrupt smooth boundary. (0 to 11 inches thick)
R--11 inches; hard sandstone.
TYPE LOCATION: San Miguel County, Colorado; about 18 miles east of Norwood, Colorado, located about 1,000 feet west and 1,350 feet north of the southeast corner, Sec. 28, T. 45 N., R. 10 W.; Sams USGS quad.; Lat. 38 degrees, 07 minutes, 11 seconds N., and long. 107 degrees, 58 minutes, 06 seconds W., NAD 27
RANGE IN CHARACTERISTICS:
Soil moisture regime: udic; dry in some part of the moisture control section for 45 to 90 cumulative days (ustic udic subclass)
Mean annual soil temperature: 39 to 41 degrees F.
Mean summer soil temperature: 52 to 58 degrees F.
Depth to lithic contact: 5 to 20
Thickness of the mollic epipedon: 5 to 15 inches
Particle-size control section:
Clay content: 18 to 27 percent
Rock fragment content: 0 to 20 percent
A horizon:
Hue: 7.5YR or 10YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist
Rock fragment content: 0 to 20 percent
Reaction: slightly acid to slightly alkaline
Bw horizon, when present:
Hue: 7.5YR or 10YR
Value: 4 to 6 dry, 2 to 4 moist
Chroma: 2 or 3, dry and moist
Rock fragment content: 0 to 20 percent
Reaction: neutral or slightly alkaline
COMPETING SERIES: These are the Hazton, Heisspitz, Lotex, Trump, and Tuggle series. In addition, these soils may be competitors when their classification is updated: Duncom, Hanagita, Jenkinson, Spliten, Splitro, and Udelope series.
Duncom: have horizons of secondary calcium carbonate accumulation.
Hazton,
Lotex,
Spliten,
Splitro, and Udelope: have less than 18 percent clay in the particle-size control section.
Hanagita: have mean annual soil temperatures of 32 to 35 degrees F.
Heisspitz: are slightly acid or moderately acid and have a typic udic moisture regime subclass.
Jenkinson: are moderately alkaline or strongly alkaline in the particle-size control section.
Trump: have a horizons of calcium carbonate accumulation with 4 to 14 percent calcium carbonate equivalent.
Tuggle: have an ustic moisture regime.
GEOGRAPHIC SETTING:
Parent material: slope alluvium derived from sandstone, shale, granite and some basalt.
Landform: hills, mesas, and structural benches.
Slopes: 0 to 40 percent
Elevation: 8,500 to 10,100 feet
Mean annual air temperature: 35 to 42 degrees F.
Mean annual precipitation: 20 to 30 inches.
Wettest months: July and August receive slightly more precipitation than other months.
Driest months: May and June receive slightly less precipitation than other months, but the soils are moist through mid June from snowmelt.
Frost-free period: 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Baird Hollow, Bushvalley, Granath, Leaps, Nordicol, and Ryman soils.
Baird Hollow soils are very deep and have an argillic horizon.
Bushvalley soils have an argillic horizon.
Granath soils are very deep.
Leaps soils do not have a lithic contact above 40 inches.
Nordicol soils are very deep, have an argillic horizon, and have greater than 35 percent rock fragments in the particle-size control section.
Ryman soils do not have a lithic contact above 40 inches and have a thick mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained, low to high runoff, moderate permeability.
USE AND VEGETATION: These soils are used for summer and fall livestock grazing and wildlife habitat. Native vegetation consists of stunted aspen and widely scattered ponderosa pine with an understory of Arizona fescue, Parry's danthonia, mountain muhly, needlegrasses, western wheatgrass, sheep fescue, mountain snowberry, and true mountain mahogany.
DISTRIBUTION AND EXTENT: Western Colorado and possibly adjacent parts of Utah. LRR E, MLRA 48A. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: San Miguel County, Colorado, San Miguel Soil Survey Area. 1987.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: The zone from 0 to 11 inches. (A and Bw horizons)
Lithic contact: hard sandstone at 11 inches.
Particle size control section: The zone from 0 to 11 inches. (A1 and Bw 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.
The moisture regime subclass is unclear; the 06/2002 revision called it ustic udic, but it may be drier for longer periods than that.