LOCATION WIGTON COEstablished Series
TAXONOMIC CLASS: Mixed, mesic Ustic Torripsamments
TYPICAL PEDON: Wigton loamy sand, grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 8 inches; brown (10YR 4/3) loamy sand, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, very friable; neutral; gradual smooth boundary. (6 to 10 inches thick)
AC--8 to 19 inches; brown (10YR 5/3) loamy sand, brown (10YR 4/3) moist; weak medium prismatic structure parting to weak fine granules; hard, very friable; neutral; gradual smooth boundary. (6 to 14 inches thick)
C--l9 to 60 inches; very pale brown (10YR 7/3) sand, pale brown (10YR 6/3) moist; massive parting to single grained; hard, very friable; neutral.
TYPE LOCATION: El Paso County, Colorado; 1,320 feet east of the SW corner of Sec. 28, T. 14 S., R. 62 W.
RANGE IN CHARACTERISTICS: Typically the soils are noncalcareous to depths of more than 60 inches and are noncalcareous to depths of more than 40 inches in all pedons. Organic carbon in the surface 15 inches averages 0.2 to 0.6 percent, and decreases uniformly with increasing depth. The control section is usually sand or loamy sand and has a high proportion of medium and coarser angular sand. Rock fragments range from 0 to 15 percent by volume, are typically less than 10 percent and are mostly fine and very fine angular granite pebbles. These soils have lower volume change on wetting and drying than do most soils having similar sand/clay ratios. Reaction ranges from pH 6.6 to 7.8. Mean annual soil temperature ranges from 47 to 58 degrees F. and mean summer soil temperature ranges from 59 to 79 degrees F.
The A horizon has hue of 2.5Y through 7.5YR, value of 4 through 7 dry, 3 through 5 moist, and chroma of 2 through 4. Primary structure is usually granular but is single-grained in some pedons. Consistence is soft or slightly hard.
The C horizon has hue of 2.5Y through 7.5YR. These materials have hard to very hard consistence when dry and tend to stand vertically in road cuts for long periods of time.
COMPETING SERIES: These are the Curtis Siding, Dwyer, Mespun, Pinavetes, Tullock and Valent series. Curtis Siding soils are predominantly fine sand or finer, and contain more than 15 percent gravel throughout the control section. Dwyer soils are predominantly fine sand or finer, and are calcareous above depth of 40 inches. Mespun soils have hue of 5YR or 7.5YR and formed in fine sand. Pinavetes soils formed in finer sand, contain lenses of gravel, and have a significant component of volcanic ash. Tullock soils are calcareous, and are underlain by a paralithic contact at depths of 20 to 40 inches. Valent soils formed in sandy eolian sediments and are not dominated by medium and coarse angular granite sand.
GEOGRAPHIC SETTING: The Wigton soils are on undulating dune-like uplands or on alluvial fans. Slopes range from 0 to about 20 percent. The soils formed in thick noncalcareous coarse angular sand derived from arkose beds or from granite bedrock. At the type location the average annual precipitation is 14 inches with peak periods of precipitation occurring in the spring and early summer. Mean annual temperature is 48 degrees F., mean summer temperature is 67 degrees F. The frost-free season is about 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Blakeland and Ellicott soils. Blakeland soils have a mollic epipedon. Ellicott soils are stratified and have an erratic placement of organic carbon with increasing depth.
DRAINAGE AND PERMEABILITY: Excessively drained; slow runoff; rapid permeability.
USE AND VEGETATION: They are used as rangeland. Native vegetation is mainly blue grama, sand reedgrass, needlegrass, sand bluestem, little bluestem, yucca, cactus and fringed sage.
DISTRIBUTION AND EXTENT: East-central Colorado. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: El Paso County, Colorado, 1975.
REMARKS: OSED scanned by NSSQA. Last revised by state 5/75.