LOCATION RICHSUM UTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Typic Calcixerepts
TYPICAL PEDON: Richsum silt loam--rangeland. (Colors are for moist soil unless otherwise stated.)
A1--0 to 2 inches; dark brown (7.5YR 3/3) silt loam, brown (7.5YR 5/4) dry; weak medium platy structure; soft, very friable, slightly sticky and slightly plastic; many very fine, fine and few medium roots; many very fine vesicular pores; 10 percent gravel; neutral (pH 7.2); abrupt smooth boundary. (2 to 4 inches thick)
A2--2 to 14 inches; dark brown (7.5YR 3/4) silt loam, brown (7.5YR 5/4) dry; weak coarse subangular blocky structure parting to moderate coarse granular; hard, friable, slightly sticky and slightly plastic; common very fine, fine and few medium roots; common fine and few medium and coarse pores; 10 percent gravel; strongly effervescent, carbonates are disseminated; slightly alkaline (pH 7.7); clear smooth boundary. (0 to 12 inches thick)
Bk1--14 to 23 inches; reddish brown (5YR 4/4) silt loam, light reddish brown (5YR 6/4) dry; weak coarse subangular blocky structure parting to strong medium subangular blocky; very hard, firm , moderately sticky and moderately plastic, few very fine, fine and medium roots; few very fine and fine pores; 5 percent gravel, 5 percent cobbles; strongly effervescent, carbonates are disseminated and in flakes; moderately alkaline (pH 7.9); clear wavy boundary. (6 to 10 inches thick)
Bk2--23 to 32 inches; reddish brown (5YR 4/4) silt loam, light reddish brown (5YR 6/4) dry; carbonates coatings are pinkish gray (5YR 7/2); weak coarse subangular blocky structure parting to strong medium subangular blocky; hard, friable, slightly sticky and slightly plastic; few very fine, fine and medium roots; few very fine and fine pores; 5 percent gravel, 5 percent cobbles; strongly effervescent, carbonates are disseminated and veined; moderately alkaline (pH 8.0); abrupt wavy boundary. (7 to 17 inches thick)
Bk3--32 to 52 inches; reddish brown (5YR 4/4) gravelly silt loam, light reddish brown (5YR 6/4) dry; massive; slightly hard, friable, sticky and slightly plastic; few very fine roots; 15 percent gravel; strongly effervescent, carbonates are disseminated; moderately alkaline (pH 8.2); clear wavy boundary. (12 to 15 inches thick)
Cr--52 inches; weathered bedrock.
TYPE LOCATION: Summit County, Utah about 16 miles northeast of Echo, Utah, located about 2,200 feet west and 2,000 feet north of the southeast corner of sec. 27, T. 5 N., R. 7 E; Shearing Corral, Utah, USGS quad; lat. 41 degrees, 8 minutes, 9 seconds N. and long. 111 degrees, 8 minutes, 20 seconds W., NAD 1927.
RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist; moist in winter and spring; dry in late summer and fall. Xeric moisture regime bordering aridic.
Mean annual soil temperature: 44 to 47 degrees F.
Ochric epipedon: commonly has a 2 to 4 inch subhorizon that meets the properties for a mollic epipedon except for thickness.
Depth to the base of the Bk horizon: 29 to 60 inches.
Depth to paralithic contact: 40 to 60 inches.
Particle-size control section: 18 to 27 percent clay and less than 15 percent rock fragments.
A horizon:
Hue: 7.5YR, 5YR or 10YR
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 2 to 4 dry; 2 to 6 moist
Carbonates: noneffervescent to strongly effervescent.
Reaction: neutral to strongly alkaline.
Bk horizon:
Hue: 7.5YR, 5YR or 2.5YR
Value: 5 to 7 dry; 4 to 6 moist
Chroma: 4 to 6 dry and moist
Texture: silt loam, loam, gravelly silt loam
Reaction: slightly alkaline to strongly alkaline.
C horizon: (Not in all pedons)
Hue: 7.5YR, 5YR or 2.5YR
Value: 6 or 7 dry; 5 or 6 moist
Chroma: 4 to 6 dry and moist.
Texture: silt loam, loam, or gravelly loam.
Carbonates: slightly effervescent or strongly effervescent
Reaction: slightly alkaline to strongly alkaline.
COMPETING SERIES: This is the Richville (UT) series. Richville soils are moderately deep.
GEOGRAPHIC SETTING: Richsum soils are on high tablelands, low mountains and valley sides at elevations of 5,600 to 7,400 feet. They formed in residuum, slope alluvium, and valley side alluvium derived from shale, sandstone and conglomerate. Slopes range from 4 to 60 percent. Aspects are mainly south, southwest. Average annual precipitation is 14 to 16 inches and mean annual temperature is 40 to 45 degrees F. The freeze-free period is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Ayoub, Gridge, and Kovich soils. Ayoub soils are moderately deep and have mollic epipedons. Gridge soils have bedrock at less than 20 inches. Kovich soils are poorly drained.
DRAINAGE AND PERMEABILITY: Well drained; medium to very rapid runoff; moderate permeability.
USE AND VEGETATION: These soils are used for rangeland. Potential vegetation is bluebunch wheatgrass, needlegrass and big sagebrush.
DISTRIBUTION AND EXTENT: High tablelands and low mountains of north central Utah. The series is moderately extensive. MLRA 47.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Summit Soil Survey Area (Summit County), Utah, 1986.
REMARKS: The diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface of the soil to 14 inches. (A1, A2 horizons)
Calcic horizon - zone of carbonate accumulation from 14 to 52 inches (Bk horizons).
Paralithic contact - at 52 inches (Cr layer).
Classification: Keys to Soil Taxonomy, Eighth Edition, 1998.