LOCATION RIMTON WYEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Ustollic Glossocryalfs
TYPICAL PEDON: Rimton loam -on a northeast facing slope of 18 percent under aspen. (Colors are for dry soil unless otherwise stated.)
0--3 to 2 inches; undecomposed organic matter; principally leaves, twigs, bark, and the fleshy remains of grasses; abrupt wavy boundary. (1 to 3 inches thick)
0i--2 to 0 inches; partially decomposed organic matter;
abrupt smooth boundary. (0 to 2 inches thick)
A--0 to 8 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; soft, very friable, slightly plastic, slightly sticky; common fine roots; common fine pores: neutral, pH 6.6 (BTB): clear smooth boundary. (5 to 9 inches thick)
E--8 to 13 inches; light brownish gray (10YR 6/2) very fine sandy loam, grayish brown (10YR 5/2) moist; weak fine platy structure that parts to moderate fine granules; soft, very friable, nonplastic, nonsticky; common fine and medium roots; common fine and medium pores: neutral ( pH 6.8); gradual wavy boundary. (3 to 8 inches thick)
E/B--13 to 22 inches; light brownish gray (10YR 6/2) sandy clay loam, grayish brown (10YR 5/2) moist surrounding smaller areas of grayish brown (10YR 5/2) dry and dark grayish brown (10YR 4/2) moist; moderate medium and fine subangular blocky structure; slightly hard, very friable, slightly plastic, slightly sticky; few distinct clay films on the vertical faces of peds within the B portion of this horizon: neutral ( pH 6.8) ; gradual wavy boundary. (3 to 12 inches thick)
Bt1--22 to 30 inches; grayish brown (10YR 5/2) sandy clay loam, dark grayish brown (10YR 4/2) moist; moderate coarse and medium subangular blocky structure; slightly hard, very friable, slightly plastic, slightly sticky; common distinct clay films on vertical ped faces; common fine and medium roots; common fine and medium pores; neutral ( pH 6.8); gradual wavy boundary. (5 to 36 inches thick)
Bt2--30 to 36 inches; yellowish brown (10YR 5/4) sandy clay loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; hard, firm, slightly plastic, slightly sticky; common distinct clay films on vertical ped faces; neutral (pH 6.8); gradual wavy boundary. (3 to 8 inches thick)
Cr--36 inches; noncalcareous soft sandy shale.
TYPE LOCATION: Carbon County, Wyoming. The SW1/4 of the SW1/4 of Sec. 29, T17N, R88W.
RANGE IN CHARACTERISTICS: These soils are normally noncalcareous throughout but some pedons have thin discontinuous subhorizons that are calcareous that occur just above the paralithic contact. The depth to paralithic contact is 20 to 40 inches. Rock fragments range from 0 to 15 percent throughout. Some pedons have a thin stone line with up to 50 percent rock fragments just above the paralithic contact. The mean annual soil temperature ranges from 36 to 44 degrees F. The mean summer soil temperature ranges from 45 to 55 degrees F.
The A horizon has hue of 10YR or 2.5Y, value of 3 through 5 dry, 2 or 3 moist and chroma of 1 through 3. Textures are sandy loam, fine sandy loam, or loam.
The E horizon has hue of 10YR or 2.5Y, value of 5 or 6 dry, 3 through 5 moist, and chroma of 2 through 4. Textures are fine sandy loam or very fine sandy loam.
The E/B horizon has hue of 10YR or 2.5Y, value of 5 or 6 dry, 3 through 5 moist, and chroma of 2 through 4. This horizon typically has more than one color and exhibits tonguing and interfingering. Textures are sandy loam or sandy clay loam with more than 35 percent fine sand or coarser.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 or 5 dry, 3 or 4 moist, and chroma of 2 through 6. Clay content is 18 to 35 percent, silt is 5 to 25 percent, and sand is 55 to 70 percent with more than 35 percent being fine or coarser sand. Some pedons have a thin transitional horizon between the base of the argillic horizon and the paralithic contact.
COMPETING SERIES: Other series in the same subgroup and family include the Amesmont (T), Beardall, Bramard, Dunlatop, Hub, Nisula, Stringham, Swapps, Telcher, Ula, and Wix series. The Bramard, Dunlatop, Hub, Nisula, Stringam,and Telcher series are deep or very deep to bedrock. The Beardall and Swapps series have a lithic contact above 40 inches. The Amesmont and Ula soils allow hues redder than 7.5YR in the Bt horizon. The Wix series does not have a E/B horizon.
GEOGRAPHIC SETTING: The Rimton soils occur on moderately steep to steep north and east facing hill and mountain slopes. Slopes typically range from 10 to 40 percent. It formed in alluvium and residuum derived from noncalcareous shale and sandstone. The mean annual precipitation is about 18 inches with peak periods of precipitation occurring in the spring and early summer months. Mean annual air temperature is 38 degrees F., mean summer air temperature is 56 degrees F., mean annual soil temperature is 41 degrees F., and mean summer soil temperature is 55 degrees F. Elevation 7,800 to 9,500 feet. The frost-free season is less than 60 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Contide and Hub series. The Contide series differs in having thin or light colored A1 horizons and in being finer textured. The Hub series differs in having no bedrock above 40 inches.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium to rapid. Permeability is moderate.
USE AND VEGETATION: These soils are used mostly for wildlife habitat and livestock grazing. Native vegetation includes aspen, Columbia needlegrass, and Oregon grape.
DISTRIBUTION AND EXTENT: Present known distribution limited to southern and western Wyoming. Series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Lakewood, Colorado
SERIES PROPOSED: Sage Creek area, Carbon County, Wyoming, 1972. Series name is a coined name.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon--0 to 8 inches (A)
2. Albic horizon--8 to 13 inches (E)
3. Argillic horizon--22 to 36 inches (Bt1,Bt2)
4. Paralithic contact--36 inches (Cr)