LOCATION NOMAD COEstablished Series
TAXONOMIC CLASS: Fine-loamy, carbonatic, mesic Typic Haplocalcids
TYPICAL PEDON: Nomad loamy sand, on a southeast facing, 2 percent slope in rangeland at an elevation of 4,940 feet. (Colors are for dry soil unless otherwise noted.) The surface is covered by 20 percent sandstone gravel.
A--0 to 2 inches; light brown (7.5YR 6/4) loamy sand, brown (7.5YR 5/4) moist; moderate medium platy structure parting to moderate very fine granular; soft, very friable, nonsticky and nonplastic; common very fine roots throughout; common very fine vesicular pores; 32 percent calcium carbonate equivalent; 5 percent sandstone gravel; violently effervescent; moderately alkaline (pH 8.0); clear wavy boundary.
Bw1--2 to 7 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 5/4) moist; weak medium subangular blocky structure parting to moderate very fine granular; slightly hard, friable, nonsticky and nonplastic; common very fine roots throughout; common very fine dendritic tubular pores; 41 percent calcium carbonate equivalent; 1 percent sandstone gravel; violently effervescent; moderately alkaline (pH 8.0); gradual wavy boundary.
Bw2--7 to 14 inches; light brown (7.5YR 6/4) loam, brown (7.5YR 5/4) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; many very fine roots throughout; common very fine and few fine dendritic tubular pores; 45 percent calcium carbonate equivalent; 1 percent sandstone gravel; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary.
2Bk--14 to 21 inches; very pale brown (10YR 7/3) clay loam, pale brown (10YR 6/3) moist; moderate medium subangular blocky structure; very hard, extremely firm, moderately sticky and moderately plastic; common very fine roots throughout; common very fine dendritic tubular pores; common medium irregular masses of carbonate and finely disseminated carbonates throughout; 58 percent calcium carbonate equivalent; 1 percent limestone parachanners; violently effervescent; moderately alkaline (pH 8.2); clear wavy boundary.
2C--21 to 30 inches; light yellowish brown (2.5Y 6/3) clay, light olive brown (2.5Y 5/3) moist; massive; slightly hard, friable, moderately sticky and moderately plastic; common very fine roots throughout; many very fine dendritic tubular pores; disseminated carbonates throughout; 50 percent calcium carbonate equivalent; 1 percent limestone parachanners; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary.
2Cr1--30 to 39 inches; highly fractured soft Greenhorn limestone; clear wavy boundary.
2Cr2--39 to 55 inches; fractured soft Greenhorn limestone.
TYPE LOCATION: Montezuma County, Colorado; about 5.5 miles northeast of the Four Corners; Sentinel Peak Southwest, Colorado USGS quad; lat. 37 degrees 01 minutes 8.17 seconds N. and long. 108 degrees 58 minutes 15.61 seconds W., NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture regime: Typic aridic
Mean annual soil temperature: 54 to 58 degrees F
Depth to paralithic contact: 20 to 40 inches to soft limestone
Depth to secondary calcium carbonate: 10 to 20 inches
Depth to calcic horizon: 10 to 20 inches
Particle-size control section (weighted average):
Clay content: 27 to 35 percent
Rock fragments: 0 to 5 percent
A horizon
Thickness: 2 to 6 inches
Hue: 7.5YR or 10YR
Value: 6 dry, 4 or 5 moist
Chroma: 4
Texture: loamy sand, sandy loam, silt loam, or loam
Clay content: 10 to 18 percent
Rock fragments: 0 to 5 percent sandstone gravel
EC (mmhos/cm): 0 to 2
Gypsum: 0 to 5 percent
Calcium carbonate equivalent: 25 to 35 percent
Reaction: moderately alkaline
Bw horizon
Thickness: 6 to 20 inches
Hue: 7.5YR or 10YR
Value: 6 or 7 dry, 5 moist
Chroma: 4
Texture: loam
Clay content: 10 to 18 percent
Rock fragments: 0 to 15 percent sandstone gravel
Gypsum: 1 to 5 percent
EC (mmhos/cm): 0 to 2
Calcium carbonate equivalent: 35 to 50 percent
Reaction: moderately alkaline
2Bk horizon
Thickness: 4 to 16 inches
Hue: 10YR or 2.5Y
Value: 6 or 7 dry, 5 or 6 moist
Chroma: 3 or 4
Texture: loam, or clay loam
Clay content: 18 to 35 percent
Rock fragments: 0 to 15 percent limestone parachanners
Gypsum: 1 to 5 percent
EC (mmhos/cm): 0 to 2
Calcium carbonate equivalent: 40 to 60 percent
Reaction: moderately alkaline
2C horizon (when present)
Thickness: 0 to 16 inches
Hue: 2.5Y
Value: 6 or dry, 5 moist
Chroma: 3
Texture: clay
Clay content: 40 to 45 percent
Rock fragments: 0 to 15 percent limestone parachanners
Gypsum: 1 to 5 percent
EC (mmhos/cm): 0 to 2
Calcium carbonate equivalent: 45 to 60 percent
Reaction: moderately alkaline
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Parent material: eolian material derived from sandstone over residuum derived from the Greenhorn member of the Mancos Shale formation
Landform: structural benches
Slopes: 1 to 6 percent
Elevation: 4,800 to 5,700 feet
Mean annual temperature: 52 to 56 degrees F
Mean annual precipitation: 7 to 10 inches
Precipitation pattern: uniform with slight dip in May and June and slight increase in July and August
Frost-free period: 135 to 160 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Greycap and Hope series. Greycap soils are shallow or very shallow to limestone and are on structural benches. Hope soils are very deep and are in broad drainageways.
DRAINAGE AND PERMEABILITY: Well drained, low or medium runoff, slow permeability.
USE AND VEGETATION: Nomad soils are used for rangeland. Native vegetation is winterfat, galleta, shadscale, and Indian ricegrass.
DISTRIBUTION AND EXTENT: Montezuma County, Colorado, Ute Mountain Indian Reservation. MLRA 35. This series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.
SERIES ESTABLISHED: Montezuma County, Colorado, Ute Mountain Area, Colorado and New Mexico, 2005.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Series control section: The zone from 0 to 40 inches.
Particle-size control section: The zone from 10 to 30 inches. (Bw2, 2Bk, and 2C horizons)
Ochric epipedon: The zone from 0 to 10 inches. (A and BA horizons)
Calcic horizon: The zone from 14 to 21 inches. (2Bk horizon)
Paralithic contact: The contact with soft limestone at 30 inches. (2Cr1 and 2Cr2 horizons)
Classified according to Keys to Soil Taxonomy Ninth Edition, 2003
ADDITIONAL DATA: Calcium carbonate equivalence was determined using a field volume calcimeter. A HACH kit was used to determine gypsum concentrations. Electrical conductivity was determined with a portable EC meter.