LOCATION SENLAR WYEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Ustic Haplocambids
TYPICAL PEDON: Senlar silt loam-on a north facing slope of one percent, utilized as rangeland. (Colors are for dry soil unless otherwise stated)
A--0 to 2 inches; light gray (10YR 7/2) silt loam, brown (10YR 5/3) moist; weak fine granular structure; a thin vesicular crust occurs on soil surface; soft, friable, slightly sticky and slightly plastic; many fine, few medium roots; slight effervescence, calcium carbonate disseminated; neutral (pH 6.8); clear smooth boundary. (1 to 9 inches thick)
Bw1--2 to 8 inches; very pale brown (10YR 7/3) silt loam, brown (10YR 5/3) moist; weak medium prismatic structure parting to weak medium angular blocky; slightly hard, friable, slightly sticky and slightly plastic; common fine, few medium roots; strong effervescence, calcium carbonate disseminated; slightly alkaline (pH 7.6); clear wavy boundary.
Bw2--8 to 16 inches; very pale brown (10YR 7/3) silt loam, brown (10YR 5/3) moist; weak medium prismatic structure parting to weak medium angular blocky; slightly hard, friable, slightly sticky and slightly plastic; common fine, few medium roots; strong effervescence, calcium carbonate disseminated; strongly alkaline (pH 8.8); clear wavy boundary. (Combined Bw horizons 10 to 22 inches thick)
Bk1--16 to 22 inches; light gray (10YR 7/2) silt loam, pale brown (10YR 6/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic common fine, few medium roots; violent effervescence, calcium carbonate disseminated and as few medium and fine filaments and threads; strongly alkaline (pH 8.9); gradual wavy boundary.
Bk2--22 to 28 inches; light gray (10YR 7/2) silt loam, brown (10YR 5/3) moist; massive; slightly hard, friable slightly sticky and slightly plastic; few medium and fine roots; violent effervescence, calcium carbonate disseminated and as common fine filaments and specks; strongly alkaline (pH 9.0); gradual wavy boundary.
2Bk3--28 to 60 inches; very pale brown (10YR 7/3) very fine sandy loam containing thin strata of fine sandy loam and silt loam, brown (10YR 5/3) moist; moderate bedding planes; slightly hard, very friable nonsticky and nonplastic; few medium and fine roots; violent effervescence, calcium carbonate disseminated and as few fine soft masses; strongly alkaline (pH 9.0).
TYPE LOCATION: Niobrara County, Wyoming; about 1,160 feet north and 700 feet west of the southeast corner of sec. 33, T. 36 N., R. 62 W. Coyote Gap Quad. 43 degrees 2 minutes 55 seconds north latitude and 104 degrees 18 minutes 13 seconds west longitude.
RANGE IN CHARACTERISTICS: Senlar soils are typically calcareous throughout due to intermittent recharge of carbonates but may be leached as deep as 6 inches in some pedons. Thin vesicular crusting occurs in many pedons. Depth to the base of the cambic horizon ranges from 13 to 29 inches. Gravel content averages 0 to 5 percent. The particle size control section averages from 18 to 35 percent clay, 60 to 70 percent silt, and less than 15 percent coarser than very fine sand. Thin discontinuous bands of up to 30 percent gravel may occur below 40 inches. The soil is dry in the moisture control section more than half the time cumulative that the soil temperature at a depth of 20 inches is 41 degrees F., which occurs about April 21 to 27. It is dry in all parts of the moisture control section for at least 60 consecutive days between July 15 to October 25. The mean annual soil temperature is 47 to 52 degrees F., and the soil temperature at a depth of 20 inches is 41 degrees F. or more for 175 to 192 days. EC is 0 to 4 mmhos.
The A horizon has hue of 10YR or 2.5Y, value of 6 or 7 dry and 4 or 5 moist, and chroma of 2 or 3. It is neutral or slightly alkaline.
The Bw horizon has hue of 10YR or 2.5Y, value of 6 or 7 dry and 4 or 5 moist, and chroma of 2 or 3. Textures are silt loam or silty clay loam with 18 to 35 percent clay, 65 to 80 percent silt and very fine sand, and less than 15 percent fine and coarser sand. It is slightly alkaline to strongly alkaline.
The Bk horizon has hue of 10YR or 2.5Y, value of 6 or 7 dry and 5 or 6 moist, and chroma of 2 through 4. Texture is dominantly silt loam, but is very fine sandy loam in the lower part in some pedons. Calcium carbonate equivalent ranges from 3 to 10 percent. Secondary carbonate accumulations in the form of few to common filaments and soft masses occur throughout this horizon. EC is 1 to 4 mmhos. It is moderately alkaline or strongly alkaline.
COMPETING SERIES: These are the Alicia, Aquima(T), Calabasas, Cedarpass, Las Lucas, Menoken, and Ruinpoint series. Alicia, Aquima, and Ruinpoint soils have hues redder than 7.5YR in the cambic horizon. Calabasas soils have calcic horizons. Cedarpass soils have SARs' greater than 10. Las Lucas and Menoken soils have bedrock above 60 inches.
GEOGRAPHIC SETTING: Senlar soils are on alluvial fans, fan terraces, and hillslopes. The soils formed in silty low energy alluvial sediments of Holocene age derived primarily from siltstone and fine grained sandstone. Slopes are 0 to 15 percent. Elevations are 3,800 to 4,800 feet. The mean annual precipitation is 10 to 14 inches, about half of which falls in April, May, and early June and less than one inch in each month of July, August, and September. The mean annual air temperature ranges from 44 to 51 degrees F. The frost-free season is 110 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cambria, Kadoka, Kishona, and Thirtynine (T) soils. Cambria and Kishona soils have fine-loamy particle size control sections. Also, Cambria soils have argillic horizons. Kadoka and Thirtynine soils have mollic epipedons and argillic horizons. Kadoka soils have siltstone bedrock at 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability.
USE AND VEGETATION: Senlar soils are utilized for livestock grazing and wildlife habitat. Some areas have been seeded to alfalfa and tame grass pasture. Principal native vegetation is western wheatgrass, green needlegrass, blue grama, and sagebrush.
DISTRIBUTION AND EXTENT: Eastern Wyoming. The series is of limited extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Niobrara County, Wyoming; 1993.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 2 inches (A)
Cambic horizon - 2 to 16 inches (Bw1, Bw2)
Ustollic subgroup - The upper 40 cm of the profile averages 0.9 percent organic carbon.
SIR- WY0783
MLRR- G