LOCATION THAYNE WY+ID MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Ustic Haplocryolls
TYPICAL PEDON: Thayne silt loam, grassland. (Colors are for dry soil unless otherwise noted.)
A--0 to 12 inches; dark grayish brown (10YR 4/2) silt loam, very dark brown (10YR 2/2) moist; strong fine granular structure; soft, very friable; 5 percent limestone gravel and flat fragments; neutral (pH 6.8); gradual smooth boundary. (6 to 15 inches thick)
Bw--12 to 24 inches; light olive brown (2.5Y 5/3) gravelly loam, olive brown (2.5Y 4/3) moist; moderate fine subangular blocky structure; few glossy patches on faces of peds; slightly hard, very friable; 15 percent limestone gravel and flat fragments; weakly calcareous; slightly alkaline (pH 7.8); diffuse wavy boundary. (10 to 25 inches thick)
Ck--24 to 60 inches; pale yellow (2.5Y 7/3) very gravelly loam, light yellowish brown (2.5Y 6/3) moist; massive; slightly hard, very friable; 40 Percent limestone gravel and cobbles; visible secondary calcium carbonate occurring as coatings on rock fragments and in thin seams and streaks; calcareous; moderately alkaline (pH 8.2).
TYPE LOCATION: Lincoln County, Wyoming; about 300 feet east of the abandoned house in the SW1/4 SW1/4 NW1/4 of sec. 35, T.36N., R.119W.
RANGE IN CHARACTERISTICS: The mollic epipedon is 7 to 15 inches thick, depth to calcareous material ranges from 0 to 15 inches, and the solum is 15 to 40 inches thick. Organic carbon in the mollic epipedon ranges from .8 to 3 percent and decreases uniformly with increasing depth. The bulk calcium carbonate equivalent, including rock fragments less than 3 inches in diameter, ranges from 10 to 35 percent in most horizons. The control section is typically gravelly loam or silt loam but clay ranges from 18 to 35 Percent, silt from 20 to 60 F percent, and sand from 20 to 50 F percent with more than 15 percent fine or coarser sand. Rock fragments in the upper part of the control section range from 5 to 35 percent and range from 35 to 80 Percent at depths of 26 to 40 inches or more. Mean annual soil temperature ranges from 32 degrees to 46 degrees F., and mean summer soil temperature ranges from 40 degrees to 58 degrees F.
The A horizon has hue of 2.5Y through 7.5YR, value of 4 or 5 dry, 2 or 3 moist and chroma of 1 through 3. It usually has granular or crumb primary structure but has subangular blocky structure in some pedons. This horizon is soft or slightly hard and is neutral or slightly alkaline.
The Bw horizon has hue of 2.5Y through 7.5YR, value of 5 or 6 dry, 4 or 5 moist and chroma of 2 or 3. It typically has subangular blocky primary structure but has weak prismatic structure in some pedons. This horizon shows some evidence of alteration such as redder hue, brighter chroma, or moderate structure, or shows some evidence of the translocation of calcium carbonate or other soluble salt. It is slightly or moderately alkaline.
The Ck horizon has hue of 5Y through 7.5YR. It contains 2 to 12 percent carbonate equivalent. This horizon is usually gravelly or very gravelly loam. It is moderately to strongly alkaline.
COMPETING SERIES: These are the Auzqui, Bynum, Dewville, Emerald, Redcloud, Tamp, Tampico, Teton, Tilton, Uhl, and Wrenman series. Auzqui, Emerald, Redcloud and Tilton soils lack a loamy-skeletal layer within the series control section. Also, Auzqui soils lack a cambic horizon, Emerald, Tamp, and Uhl soils are noncalcareous throughout and Tilton soils have a much weaker horizon of secondary carbonate accumulation. Bynum soils have a paralithic contact at depths of 20 to 40 inches. Teton and Wrenman soils have a lithic contact at depths of 20 to 40 inches. Tampico soils have lithochromic hue of 5YR or redder and lack continuous horizons of secondary carbonate accumulation.
GEOGRAPHIC SETTING: Thayne soils are on alluvial fans and valley sideslopes. Slopes typically range from 0 to 20 percent. These soils formed in thick, calcareous, medium to moderately coarse material that becomes increasingly gravelly with increasing depth. At the type location the average annual precipitation is 18 inches with nearly equal amounts of precipitation in each month. Mean annual temperature is 39 degrees F., mean summer temperature is 58 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Greyback and Osmund series. Greyback soils have more than 35 percent gravel in the upper part of the control section. Osmund soils have mollic epipedons more than 16 inches thick
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used for irrigated and dry cropland, and for native pasture. Native plants are bluegrass, timothy, sagebrush, and clover.
DISTRIBUTION AND EXTENT: Mountain areas of Colorado, Wyoming, and Idaho. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lincoln County (Star Valley S.C.D.), Wyoming, 1945.