LOCATION MCFADDEN WY UT SDEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Ustic Haplocalcids
TYPICAL PEDON: McFadden gravelly sandy loam-rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 3 inches; grayish brown (10YR 5/2) gravelly sandy loam, dark brown (10YR 3/3) moist; moderate very fine granular structure; soft, very friable, nonsticky and nonplastic; many fine and very fine roots; strongly effervescent, calcium carbonate disseminated; 20 percent rounded pebbles; moderately alkaline (pH 8.4); clear smooth boundary. (1 to 4 inches thick)
Bw--3 to 7 inches; brown (10YR 5/3) gravelly sandy loam, dark brown (10YR 4/3) moist; moderate and weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; many fine roots; strongly effervescent, calcium carbonate disseminated and as few fine filaments and crusts on underside of some rock fragments; 20 percent rounded pebbles; moderately alkaline (pH 8.4); gradual wavy boundary. (0 to 5 inches thick)
Bk1--7 to 14 inches; pale brown (10YR 6/3) gravelly sandy loam, brown (10YR 5/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common medium roots; violently effervescent, calcium carbonate as common soft masses, threads and as distinct coatings on the bottom of rock fragments; 20 percent rounded pebbles; moderately alkaline (pH 8.4); gradual wavy boundary.
Bk2--14 to 35 inches; very pale brown (10YR 8/2) gravelly sandy loam, pale brown (10YR 6/3) moist; massive; slightly hard, very friable; violently effervescent, calcium carbonate as soft masses, threads, and filaments and as prominent coatings on rock fragments; 20 percent rounded and semirounded pebbles; strongly alkaline (pH 8.6); gradual wavy boundary.
Bk3--35 to 60 inches; pale yellow (2.5Y 7/4) gravelly sandy loam, light yellowish brown (2.5Y 6/4) moist; massive; slightly hard, very friable; violently effervescent, calcium carbonate as common soft masses, threads, and filaments and as distinct coatings on rock fragments; moderately alkaline (pH 8.4). (The combined thickness of the Bk horizons is 54 to greater than 60 inches.)
TYPE LOCATION: Carbon County, Wyoming; about 125 feet east of the SW corner of Sec. 32, T. 20 N., R. 77 W. Pierce Reservoir Quadrangle. 41 degrees 39 minutes 24 seconds north latitude and 106 degrees 4 minutes 52 seconds west longitude.
RANGE IN CHARACTERISTICS: These soils are typically calcareous to the surface but are leached a few inches in some pedons. The mean annual soil temperature ranges from 39 to 47 degrees F., and the mean summer temperature ranges from 59 to 63 degrees F. The particle-size control section is sandy loam, fine sandy loam, or loam with 5 to 18 percent noncarbonate clay and over 45 percent sand of which 35 percent or more is fine or coarser sand. Rock fragments range from 0 to 35 percent and are mainly rounded pebbles. A few cobbles are in some pedons but average less than 5 percent. Exchangeable sodium is less than 12 percent throughout and typically range from 1 to 5 percent. EC is less than 2 mmhos in the surface and is less than 4 mmhos in the subsoil and substratum.
The A horizon has hue of 2.5Y or 10YR, value of 4 through 6 dry, 3 or 4 moist, and chroma of 2 through 4. It is moderately alkaline or strongly alkaline.
The Bk horizon has hue of 2.5Y or 10YR, value of 5 through 8 dry, 4 through 7 moist, and chroma of 2 through 4. The upper part is transitional to the calcic horizon in some pedons. Calcium carbonate equivalent ranges from 10 to 30 percent in the calcic horizon but is less in the transitional horizons in some pedons. It is moderately alkaline or strongly alkaline.
COMPETING SERIES: These are the Amesha, Fiveoh, and Kalsted series. Amesha soils have less than 35 percent fine or coarser sand in the control section. Fiveoh soils have hue of 7.5YR through 2.5YR in the subsoil and substratum. Kalsted soils are stratified above 40 inches.
GEOGRAPHIC SETTING: McFadden soils are on relict fan aprons, alluvial terraces, and fan pediments. They formed in mixed, calcareous alluvium. Slopes are 0 to 12 percent. Elevations are 5,800 to 7,800 feet. The mean annual precipitation ranges from 8 to 14 inches with about half falling as snow and less commonly as rain in April, May, and early June. The mean annual temperature ranges from 36 to 44 degrees F. The frost-free season is estimated to range from 60 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alcova, Bosler, Elk Mountain, Ryan Park, and Lupinto soils. All of these soils have an argillic horizon. Also, Alcova soils are fine-loamy; Bosler soils have contrasting loamy-skeletal substratum above 40 inches; and Lupinto soils are loamy-skeletal.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Rangeland and wildlife habitat. Native vegetation consists of Indian ricegrass, needleleaf sedge, thickspike wheatgrass, silver sagebrush, and threadleaf sedge.
DISTRIBUTION AND EXTENT: High basins and plateaus of southern and central Wyoming. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Natrona County, Wyoming; 1985.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 3 inches (A)
Calcic horizon - 7 to 60 inches (Bk1,Bk2,Bk3)
MLRR - D
SIRs' - WY0432, WY0792, WY0799, WY0879, WY0891, WY1201
Classification updated to "superactive" December 1999. Description last updated by state July 1995.