LOCATION HESPERUS CO+NM UT WY
Established Series
Rev. GB/DKR/TWH/KLS
04/2018
HESPERUS SERIES
The Hesperus series consists of very deep, well to moderately well drained soils that formed in alluvium, slope alluvium, colluvium, residuum, or eolian material derived from mixed sources. Hesperus soils are on drainageways, alluvial fans, structural benches, terraces, mountain slopes, and hillslopes. Slopes range from 0 to 65 percent. Mean annual precipitation is about 510 mm and the mean annual air temperature is about 5.6 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Pachic Argiustolls
TYPICAL PEDON: Hesperus loam in grassland. (Colors are for dry soil unless otherwise noted.)
A--0 to 15 cm; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; neutral (pH 6.8); clear smooth boundary. (10 to 25 cm thick)
BAt--15 to 28 cm; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; weak medium prismatic structure parting to moderate fine subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; few clay films on faces of peds; neutral (pH 6.8); clear smooth boundary. (8 to 33 cm thick)
Bt1--28 to 74 cm; dark grayish brown (10YR 4/2) clay loam, very dark brown (10YR 2/2) moist; moderate medium prismatic structure parting to moderate fine subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; nearly continuous clay films on faces of peds and in root channels and/or pores; neutral (pH 7.0); clear smooth boundary.
Bt2--74 to 97 cm; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium prismatic structure parting to moderate fine subangular blocky; slightly hard, very friable, slightly sticky and slightly plastic; faint continuous clay films on faces of peds and in root channels and/or pores; neutral (pH 7.0); clear smooth boundary. (combined thickness of Bt1, Bt2 horizons - 38 to 136 cm)
Bt3--97 to 112 cm; brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few faint clay films on faces of peds and few discontinuous clay films in root channels and/or pores; neutral (pH 7.2); gradual smooth boundary. (0 to 20 cm thick)
C--112 to 152 cm; brown (10YR 5/3) loam, brown (10YR 4/3) moist; few small faint pale brown (10YR 6/3) iron concentrations; massive; hard, friable, slightly sticky and slightly plastic; neutral (pH 7.2).
TYPE LOCATION: Montezuma County, Colorado; about 3 meters south of the southwest corner of the corral at the abandoned railroad station of Glencoe, Colorado; in the SW 1/4 of Sec. 22, T. 37 N., R. 14 W.; Dolores East, Colorado USGS quad; Lat. 37 degrees, 26 minutes, 39 seconds N. and Long. 108 degrees, 23 minutes, 01 seconds W., NAD 27.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 5.6 to 7.8 degrees C.
Depth to the base of the argillic horizon: 43 to 152 cm
Depth to endosaturation: more than 100 cm
Depth to redoximorphic concentrations: more than 100 cm
Thickness of the mollic epipedon: 43 to 152 cm
Particle-size control section:
Clay content: 18 to 35 percent
A horizon
Hue: 10YR to 5Y
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 to 3, dry or moist
Texture: loam or sandy loam
Rock fragments: 0 to 15 percent, mainly sandstone gravel and cobble
Reaction (pH): 6.1 to 7.8
Bt horizon
Hue: 10YR to 5Y
Value: 3 to 7 dry, 2 to 6 moist
Chroma: 1 to 4, dry or moist
Texture: loam, clay loam, or sandy clay loam with 20 to 60 percent sand and less than 35 percent being fine or coarser sand
Rock fragments: 0 to 15 percent, mainly sandstone gravel and cobble
Reaction (pH): 6.1 to 7.8
C horizon
Hue: 10YR to 5Y
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 2 to 6, dry or moist
Texture: loam or clay loam
Rock fragments: 0 to 15 percent, mainly sandstone gravel and cobble
Reaction (pH): 6.1 to 7.8
COMPETING SERIES:
Bowbells (ND) - have calcium carbonate accumulation
Cambern (AZ) - are moderately deep to lithic contact
Carfall (MT) - do not have endosaturation and redoximorphic features
Center Creek (UT) - have a lithologic discontinuity; have more than 30 percent rock fragments in the lower part of the subsoil
Chugcreek (WY) - are moderately deep to lithic contact; formed in granite
Detra (UT) - are deep to lithic contact
Fiesta (NM) - have calcium carbonate accumulation; have hues redder than 10YR
Flaxton (ND) - have a lithologic discontinuity; have calcium carbonate accumulation
Gordo (AZ) - are deep to paralithic contact; have a lithologic discontinuity; have calcium carbonate accumulation
Hereford (AZ) - have calcium carbonate accumulation
Jaythree (NM) - have more than 35 percent fine and coarser sand; do not have endosaturation and redoximorphic features
Lacycreek (MT) - do not have endosaturation and redoximorphic features; have a lithologic discontinuity
Ohwiler (CO) - do not have endosaturation and redoximorphic features
Pachel (MT) - have calcium carbonate accumulation
Schauson (UT) - are bordering on aridic moisture regime; have igneous extrusive rock fragments; formed in basalt
Shermap (CO) - have a mollic epipedon thickness less than 60 cm; do not have endosaturation and redoximorphic features
Southbaldy (CO) - are moderately deep to lithic contact
Todacheene (NM) - have hues redder than 10YR; have igneous extrusive rock fragments; formed in basalt
Tschicoma (NM) - have igneous extrusive rock fragments; formed in dacite, latite and ryolitic tuff
Weed (CO) - have calcium carbonate accumulation
GEOGRAPHIC SETTING:
Landform - drainageways, alluvial fans, structural benches, terraces, mountain slopes and hillslopes
Elevation - 1,890 to 2,655 meters
Slopes - 0 to 65 percent
Parent material - alluvium, colluvium, residuum, slope alluvium or eolian material derived from mixed sources
Precipitation pattern - evenly distributed throughout the year; however, July and August are slightly wetter and June is slightly dryer
Mean annual air temperature - 4.4 to 8.3 degrees C.
Mean annual precipitation - 380 to 640 mm
Frost-free period - 75 to 110 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND PERMEABILITY: well to moderately well drained, negligible to very high runoff, moderate to slow permeability
USE AND VEGETATION: They are used principally for grazing land. Native vegetation is sagebrush, western wheatgrass, and bluegrass.
DISTRIBUTION AND EXTENT: Southwest Colorado, New Mexico, Utah, and
Wyoming. LRR D, E; MLRA 36, 39, 46, 48A. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Wetherill Mesa Area, Mesa Verde National Park, Colorado. 1965. The name is a local community in southwest Colorado.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 97 cm (A, BA, Bt1, and Bt2)
Argillic horizon - 28 to 97 cm (Bt1 and Bt2)
Redoximorphic features - redox concentrations from 112 to 152 cm (C horizon)
Particle-size control section - 28 to 78 cm (Bt1 and Bt2)
Note: The original concept for parent materials and landforms for this soil, as used in southwest Colorado, was loamy alluvium and slope alluvium derived from mixed sources on drainageways, terraces, valley floors and alluvial fans with less than 12 percent slopes. All pedons of Hesperus where the parent material is colluvium, residuum, or eolian deposits and the landforms are mountain slopes and hills and the percent slope is greater than 25 percent should be removed from the Hesperus concept.
Hesperus soils have a frigid temperature regime and are in an ustic soil moisture regime with a typic subclass.
National Cooperative Soil Survey
U.S.A.