LOCATION MOSROC WYEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Lithic Argicryolls
TYPICAL PEDON: Mosroc very gravelly fine sandy loam on south- facing convex slope of 3 percent-utilized as rangeland (Colors are for dry soil unless otherwise stated).
A--0 to 2 inches; (brown (10YR 5/3) very gravelly fine sandy loam, dark brown (10YR 3/3) moist; weak medium and fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine, and common medium roots; 35 percent pebbles and channers; moderately alkaline (pH 8.0); abrupt smooth boundary. (1 to 5 inches thick)
BA--2 to 5 inches; dark yellowish brown (10YR 4/4) very gravelly sandy clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure parting to weak medium granular; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, fine, and few medium roots; 40 percent pebbles and channers; moderately alkaline (pH 8.0); clear smooth boundary. (0 to 6 inches thick)
Bt--5 to 12 inches; dark brown (7.5YR 4/4) very gravelly sandy clay loam, dark brown (7.5YR 3/2) moist; weak medium prismatic structure parting to strong medium subangular blocky; slightly hard, very friable, sticky and plastic; common very fine, fine, and medium roots; continuous thin and few moderately thick clay films on faces of peds; 40 percent pebbles; moderately alkaline (pH 8.0); clear smooth boundary. (5 to 12 inches thick)
C--12 to 18 inches; yellowish brown (10YR 5/4) very gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine, fine, and medium roots; 55 percent pebbles, 5 percent cobbles; moderately alkaline (pH 8.0); abrupt wavy boundary.
(0 to 8 inches thick)
R--18 to 60 inches; granite bedrock many feet thick.
TYPE LOCATION: Fremont County, Wyoming; 1,200 feet south, 800 feet west of the NE corner of sec. 2, T. 28 N., R. 98 W.
RANGE IN CHARACTERISTICS: Depth to bedrock ranges from 9 to 20 inches. The mollic epipedon ranges from 7 to 15 inches thick. The soil is typically noncalcareous throughout, but some pedons are calcareous immediately above the bedrock. About 25 to 60 percent of the surface is covered with angular pebbles, cobbles, or stones. The mean annual soil temperature is 39 to 45 degrees F., and the mean summer temperature is 54 to 49 degrees F. Stoniness class ranges from 0 to 3. Rockiness class ranges from
0 through 2.
The A horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 through 4 dry and 2 or 3 moist. Coarse fragments range from 15 to 50 percent pebbles, 0 to 20 percent angular cobbles, and 0 to 3 percent stones. Reaction is neutral through moderately alkaline.
The Bt horizon has hue of 10YR or 7.5YR; value of 4 or 5 dry, 2 through 4 moist, and chroma of 2 through 4 dry and moist. Matrix texture is loam, clay loam, or sandy clay loam with 18 to 35 percent clay. Coarse fragments range from 30 to 55 percent pebbles, 0 to 30 percent angular cobbles, and 0 to 10 percent stones. Reaction is neutral through moderately alkaline.
The C horizon when present has hue of 2.5Y through 7.5YR; value of 5 or 6 dry, 4 or 5 moist, and chroma of 3 or 4 dry and moist. Matrix texture is loam, sandy loam, or sandy clay loam. Coarse fragments range from 30 to 55 percent pebbles, 5 to 30 percent angular cobbles, and 0 to 10 percent stones.
COMPETING SERIES: These are the Bushwalley, Genoa, and Nielsen series. Bushwalley soils formed in material weathered from tuff and ash. Genoa and Nielsen soils formed on residuum weathered from sandstone. Genoa soils have a Bt with hue of 5YR.
GEOGRAPHIC SETTING: The Mosroc soils are on granite mountain ridges and hillslopes. Schist and gneiss dikes have dissected the area. These soils formed in residuum and colluvial slopewash derived from granite. Slopes range form 1 to 15 percent. Elevation is 7,000 to 8,500 feet. The mean annual temperature is 36 to 42 degrees F., and the mean annual precipitation is 10 to 14 inches. The estimated frost-free season is 60 to 90 days but frost can occur at any time.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hoodle, Irigul, Lymanson, and Midelight series. Hoodle, Lymanson, and Midelight soils have bedrock deeper than 20 inches. Irigul soils lack argillic horizons and they are calcareous.
DRAINAGE AND PERMEABILITY: Well drained; slow or medium runoff depending upon slope; and moderate permeability.
USE AND VEGETATION: These soils are used for rangeland. Native vegetation is Sandberg bluegrass, sheep fescue, bluebunch wheatgrass, needleandthread, and big sagebrush.
DISTRIBUTION AND EXTENT: Of minor extent in the mountainous areas of south central Wyoming.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Fremont County, Wyoming; 1985.