LOCATION DEMPSEY WY

Inactive Series
Rev. AJC
05/2017

DEMPSEY SERIES

Typically they have friable granular noncalcareous A horizons, moderately coarse textured noncalcareous B2t horizons having prismatic to blocky structure, and moderately coarse textured noncalcareous C horizons.

TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Pachic Argiustolls

TYPICAL PEDON: Dempsey sandy loam - grassland. (Colors are fore dry soil unless otherwise stated).

A11--0 to 8 inches; grayish brown (10YR 5/2) light fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular or crumb structure; soft, very friable; noncalcareous, mildly alkaline, pH 7.4 (PR); gradual smooth boundary. (6 to 10 inches thick).

A12--8 to 30 inches; grayish brown (10 YR 5/2) light fine sandy loam, dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure that parts to moderate fine granules; slightly hard, very friable; noncalcareous, mildly alkaline, pH 7.6 (PR); gradual wavy boundary. (14 to 30 inches thick).

B2t--30 to 44 inches; light olive brown (2.5 5/3) fine sandy loam, olive brown (2.5Y 4/3) moist; weak very coarse prismatic structure breaking to moderate coarse subangular blocks; slightly hard, very friable; common numbers of glossy patches on ped faces; glossy coatings on the inside of root channels; wax-like bridges between sand grains; noncalcareous, mildly alkaline pH 7.8 (PR); diffuse wavy boundary. (10 to 40 inches thick).

C--40 to 60 inches; light yellowish brown (2.5Y 6/3) light fine sandy loam, light olive brown (2.5Y 5/3) moist; massive; slightly hard, very friable; noncalcareous, mildly alkaline, pH 7.8 (PR)>

TYPE LOCATION: Lincoln County, Wyoming. Approximately 1,056 feet west and 530 feet south of the N 1/4 corner of sec. 4, T 26N, R 116W.

RANGE IN CHARACTERISTICS: These soils have mollic epipedons and argillic horizons. Thickness of the mollic epipedon ranges from 25 to 40 inches. Thickness of the solum ranges from 36 to 60 inches, and there should be no bedrock or strongly contrasting substratums above 40 inches or immediately below the solum if thicker than 40 inches. These soils are noncalcareous throughout and they do not have horizons of visible secondary carbonate accumulation. The content of carbon normally ranges from .8 to 3 percent in the mollic epipedon and decreases uniformly with depth. Usually conductivity is less than 1 millimho and exchangeable sodium percentage is less than 1. The soil is 80 to 100 percent base saturated. Content of coarse fragments ranges from 0 to 15 percent but is typically less than 5 percent. Mean annual soil temperature ranges from 32 degrees F. to 47 degrees F., and mean summer soil temperature ranges from 59 degrees F. to 70 degrees F.
Colors of the A horizon may range in hue from 5Y to 7.5YR, in value from 4 to 5 dry or 2 to 3 moist, and in chroma from 2 to 3. Reaction normally ranges from pH 6.6 to pH 7.8 (1:5 dilution organic dye). Primary structure is usually granular in the upper part and subangular blocky in the lower part of the horizon. Consistence ranges from soft to slightly hard.
Color of the B2t horizon may range in hue from 5Y to 7.5YR, in value from 5 to 6 dry or 3 to 5 moist, and in chroma from 2 to 4. Reaction normally ranges from pH 6.6 to pH 7.8 (1:5 dilution organic dye). Primary structure is usually very coarse prismatic but may be subangular blocky. Texture is typically a fine sandy loam, but clay may range from 8 to 18 percent, silt from 5 to 35 percent and sand from 50 to 82 percent with more than 35 percent being fine or coarser sand. Oriented clay films occur in some part of this horizon.
Hue of the C horizon may range from 5Y to 7.5YR. Reaction normally ranges from pH6.6 to pH 7.8 (1:5 dilution organic dye). Texture is typically a light sandy loam, but the horizon should have less than 18 percent clay.

COMPETING SERIES: There are no series presently in this subgroup and family. Similar and related series include the Elzinga and Osha series. The Elzinga series differs in being finer textured, in lacking continuous argillic horizons, and in having more than 35 percent coarse fragments. The Osha series differs in having more than 35 percent coarse fragments, in lacking mollic epipedons more than 24 inches thick, and in having developed in materials weathered from granite containing a high proportion of medium and coarse granite sand.
The Dempsey series occurs on gently to moderately sloping alluvial fans generally in areas where snow accumulates in the winter months. Slopes typically range from 2 percent to about 15 or more percent. The soil is developing in thick, noncalcareous, alluvial fan materials derived from sandstone and loamstone. At the type location the average annual precipitation is 10 inches with peak periods of precipitation occurring in the spring and early summer months. Mean annual air temperature is 40 degrees F., mean summer air temperature is 60 degrees F., mean annual soil temperature is 45 degrees F., and mean summer soil temperature is 61 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Bundy and Ziller series. The Bundy series differs in lacking a mollic epipedons less than 20 inches thick, and in having the top of their argillic horizon above 24 inches.

DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is slow. Permeability is rapid.

USE AND VEGETATION: They are used principally as native pastureland. Native vegetation includes big sage, Snowberry, basin wild-rye, thickspike theatgrass, and Sandbergs bluegrass.

DISTRIBUTION AND EXTENT: Present known distribution limited to mountain valleys of Wyoming and Colorado. The series is of limited extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES PROPOSED: Lincoln County, Wyoming, 1970. Series name taken from a ridge in Lincoln County.

OSED scanned by NSSQA. Last revised by state on 6/70.

National Cooperative Soil Survey
U.S.A.