LOCATION CORDESTON WY+SDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Cumulic Hapludolls
TYPICAL PEDON: Cordeston loam, on a south facing slope of 4 percent under native grassland vegetation. When described, the soil was very moist from the surface to 33 cm and moist from 33 to 152 cm. (Colors are for moist soil unless otherwise stated.)
A1--0 to 8 cm; very dark grayish brown (10YR 3/2) loam, dark grayish brown (10YR 4/2) dry; moderate medium and coarse granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine and medium roots; neutral; clear smooth boundary. (5 to 13 cm thick)
A2--8 to 20 cm; very dark gray (10YR 3/1) loam, very dark grayish brown (10YR 3/2) dry; weak fine and medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many fine and medium roots; neutral; clear smooth boundary. (10 to 18 cm thick)
Bw1--20 to 38 cm; very dark gray (10YR 3/1) loam, dark gray (10YR 4/1) dry; weak medium and coarse angular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few coarse roots; neutral; gradual wavy boundary.
Bw2--38 to 66 cm; very dark gray (10YR 3/1) loam, dark gray (10YR 4/1) dry; weak coarse angular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few coarse roots; neutral; gradual wavy boundary.
Bw3--66 to 102 cm; dark brown (7.5YR 3/2) loam, brown (7.5YR 4/2) with streaks of brown (7.5YR 5/4) dry; weak medium and coarse angular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; slightly alkaline (pH 7.4); clear smooth boundary. (The combined thickness of the Bw horizons is 53 to 86 cm)
C--102 to 152 cm; brown (7.5YR 4/2) loam, brown (7.5YR 5/4) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; slightly alkaline.
TYPE LOCATION: Crook County, Wyoming; about 1.6 km (one mile) southeast of historic Moskee townsite; in the NW1/4 NE1/4 of sec. 9, T. 49 N., R. 61 W.; Moskee quadrangle; 44 degrees 15 minutes 12 seconds north latitude and 104 degrees 10 minutes 50 seconds west longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Udic Soil Moisture Regime
Mean annual soil temperature: 5 to 8 degrees
Mean summer soil temperature: 9 to 13 degrees C
Thickness of the mollic epipedon: 91 to 127 cm
Depth to calcium carbonate: typically greater than 152 cm; some pedons are weakly calcareous from 102 to 152 cm
Particle-size control section:
Clay content: 18 to 27 percent
Sand content: 15 to 35 percent fine and coarser sand
Rock fragments: 0 to 10 percent angular and/or subangular sandstone gravel
A Horizon:
Hue: 7.5YR, 10YR
Value: 2 or 3, 3 or 4 dry
Chroma: 1 or 2
Texture: loam, very fine sandy loam, silt loam
Rock fragments: 0 to 5 percent
Reaction: neutral or slightly alkaline
Bw Horizon:
Hue: 7.5YR or 10YR
Value: 2 or 3, 3 or 4 dry
Chroma: 1 or 2
Texture: loam, very fine sandy loam, or silt loam
Reaction: neutral or slightly alkaline
C Horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5, 4 through 6 dry
Chroma: 2 to 4
Texture: loam, very fine sandy loam, silt loam, clay loam
Reaction: neutral through moderately alkaline
COMPETING SERIES:
Darnen - typically have carbonates less than 153 cm; they form in colluvial/alluvial sediment from glacial moraines
Delette,
Frolic and
La Prairie - are moderately well drained with a seasonal high water table between 92 and 152 cm; additionally Delette soils typically have an O horizon and LaPrairie soils typical have carbonates less than 1 meter.
Everts - have 30 to 65 percent fine and coarse sand in the particle-size control section, and formed in loamy sediments overlying coarse textured outwash
Southhaven - typically are more acid in the control section; they formed in loamy sediments overlying sand on pitted outwash plains and stream terraces
GEOGRAPHIC SETTING:
Parent material: Slope alluvium, typically derived from mixed sedimentary sources including sandstone, limestone, and siltstone; in some areas, the source material includes metamorphic rock sources, dominantly schists or metaconglomerates
Landform: Fan aprons and fan piedmonts, and in drainageways and valley fill positions in mountains
Slopes: 0 to 10 percent
Elevation: 1,340 to 1,890 meters
Mean annual temperature: 5 to 7 degrees C
Mean annual precipitation: 508 to 762 mm
Precipitation pattern: Over one-half the mean annual precipitation falls as snow and rain during the period March through June
Frost-free season: 90 to 120 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Citadel and
Marshbrook soils.
Citadel - have argillic horizons and do not have mollic epipedons, additionally Citadel soils are fine-textured; they occur on higher landscape positions
Marshbrook - are poorly drained; they generally occur in swales and drainages below the Cordeston soils
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderately high saturated hydraulic conductivity; surface runoff is low to medium.
USE AND VEGETATION: Most of the Cordeston soils are used for grazing. Some areas are used for production of small grain, alfalfa, and tame pasture. Native vegetation is primarily Kentucky bluegrass, Columbia needlegrass, big bluegrass, and black medic clover.
DISTRIBUTION AND EXTENT: Cordeston soils are within the low limestone physiographic area of the Black Hills of Wyoming and South Dakota; LRR G, MLRA 62. The series is of limited extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Crook County, Wyoming; 1978.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 102 cm; (A1, A2, Bw1, Bw2, and Bw3 horizons)
The series soil moisture regime is revised to udic to reflect more current precipitation data and better understanding of soil moisture characteristics within the series domain.
Keys to Soil Taxonomy, Tenth Ed., 2006
ADDITIONAL DATA: