LOCATION STORSUN WYEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, carbonatic, mesic Ustic Haplocalcids
TYPICAL PEDON: Storsun very gravelly loam - rangeland. (Colors are for dry soil unless otherwise noted.)
The surface is covered by about 50 percent gravel, cobbles, channers, and stones.
A--0 to 4 inches: grayish brown (10YR 5/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; common fine and very fine roots and few medium roots; violently effervescent, calcium carbonate disseminated; 25 percent gravel and 10 percent cobble; slightly alkaline (pH 7.6); clear wavy boundary. (3 to 5 inches thick)
Bw--4 to 8 inches; pale brown (10YR 6/3) very gravelly loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots and few fine and medium roots; common very fine and fine tubular pores; violently effervescent, calcium carbonate disseminated; 25 percent gravel and 10 percent cobble; moderately alkaline (pH 8.0); abrupt wavy boundary. (3 to 10 inches thick)
Bk1--8 to 25 inches; very pale brown (10YR 7/3) very cobbly loam, very pale brown (10YR 7/3) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; few fine and very fine roots; common very fine and fine tubular pores; violently effervescent, calcium carbonate disseminated and as pendants on rock fragments; 55 percent calcium carbonate equivalent; 25 percent gravel, 25 percent cobble and 5 percent stones; moderately alkaline (pH 8.2); clear wavy boundary. (15 to 25 inches thick)
Bk2--25 to 60 inches; very pale brown (10YR 7/4) very cobbly loam, light yellowish brown (10YR 6/4) moist; massive; slightly hard, very friable, sticky and plastic; violently effervescent, calcium carbonate disseminated and as pendants on rock fragments; 30 percent calcium carbonate equivalent; 20 percent gravel, 30 percent cobble and 10 percent stones; moderately alkaline (pH 8.4).
TYPE LOCATION: Platte County, Wyoming; about 6 miles north of Guernsey, Wyoming; located about 2,100 feet east and 1,300 feet north of the southwest corner of sec. 2, T. 27 N., R. 66 W.
RANGE IN CHARACTERISTICS:
Soil moisture: Aridic moisture regime bordering on ustic.
Mean annual air temperature: 46 to 48 degrees F
Depth to calcic horizon: 6 to 15 inches
Particle-size control section (weighted average):
Clay content: 18 to 25 percent
Rock fragments: 20 to 30 percent gravel, 20 to 40 percent cobble and 0 to 10 percent stones.
A horizon:
Value: 5 or 6 dry, 3 through 5 moist
Chroma: 2 or 3
Rock fragments: 35 to 55 percent total fragments
Bw horizon:
Value: 5 or 6 dry
Chroma: 2 or 3
Texture: very gravelly loam or gravelly loam
Rock fragments: 30 to 50 percent total fragments
Bk horizon:
Value: 7 or 8 dry, 5 through 7 moist
Chroma: 3 or 4
Texture: very cobbly loam or very cobbly sandy clay loam
Clay content: 18 to 25 percent
Rock fragments: 20 to 30 percent gravel, 20 to 40 percent cobble and 0 to 10 percent stone
Calcium carbonate equivalent: 40 to 60 percent
COMPETING SERIES: These are the Ildecarb (NM), Ladron (NM), Moab (UT), Puice (NM), Socorro (NM), Stormitt (UT), and Tusayan (AZ) series. The Ildecarb soils contain 5 to 15 percent gypsum in the fine earth fraction in the 10 to 40 inch section. The Ladron soils have a lithologic discontinuity within a depth of 40 inches. The Moab soils contain less than 18 percent clay in the 10 to 40 inch particle size control section. The Puice, Socorro, and Tusayan soils have bedrock between a depth of 20 to 40 inches. The Stormitt soil has hues of 5YR.
GEOGRAPHIC SETTING:
Parent material: alluvium derived from sandstone
Landform: hillslopes
Slopes: 3 to 50 percent
Elevation: 4,500 to 5,800 feet
Mean annual temperature: 46 to 48 degrees F
Mean annual precipitation: 12 to 15 inches
Frost-free period: 110 to 130 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Selpats, Snavee, Sunup, and Wagonhound series. The Selpats and Wagonhound soils do not have greater than 35 percent rock fragments in the particle size control section. The Snavee soils have less than 40 percent calcium carbonate equivalent. The Sunup soils have sandstone at a depth of less than 20 inches.
DRAINAGE AND PERMEABILITY: Well drained, slow to medium runoff, moderate permeability.
USE AND VEGETATION: These soils are used for rangeland. Vegetation is needleandthread, bluebunch wheatgrass, little bluestem, mountain mahogany, and western wheatgrass.
DISTRIBUTION AND EXTENT: Southeastern Wyoming; LRR G, MLRA 67; moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES PROPOSED: Platte county, Wyoming, Platte County soil survey area, Wyoming. The name was coined from the Stormitt soil and Sunup soil.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: the zone from 10 to 40 inches. (Bk1, Bk2 horizons)
Ochric epipedon: the zone from 0 to 4 inches. (A horizons)
Cambic horizon: The zone from 4 to 8 inches. (Bw horizons)
Calcic horizon: The zone from 8 to 60 inches. (Bk1, Bk2 horizons)