LOCATION HERD UTEstablished Series
TAXONOMIC CLASS: Fine, smectitic Vertic Haplocryalfs
TYPICAL PEDON: Herd cobbly clay loam--rangeland. (Colors are for moist soil unless otherwise noted.)
A1--0 to 3 inches; very dark brown (10YR 2/2) cobbly clay loam, dark yellowish brown (10YR 4/4) dry; moderate fine granular structure; soft, very friable and slightly plastic; many fine and very fine roots; 20 percent cobbles and 10 percent pebbles; slightly acid (pH 6.2); abrupt smooth boundary. (3 to 9 inches thick)
A2--3 to 10 inches, brown (7.5YR 4/2) cobbly clay loam, brown (7.5YR 5/4) dry; weak medium and coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; few very fine pores; 15 percent cobbles and 10 percent pebbles; slightly acid (pH 6.2); clear smooth boundary. (5 to 13 inches thick)
A3--10 to 20 inches; brown (7.5YR 4/4) cobbly clay loam, brown (7.5YR 5/4) dry; weak fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and few coarse roots; few very fine pores; 15 percent cobbles and 10 percent pebbles; medium acid (pH 5.6); clear irregular boundary. (0 to 11 inches thick)
2Bt1--20 to 29 inches, yellowish red (5YR 4/6) clay, yellowish red (5YR 5/6) dry; faces of peds are brown (7.5YR 4/2) and light yellowish brown (10YR 6/4) dry; weak medium prismatic structure parting to moderate medium and coarse subangular blocky; very hard, very firm, sticky and very plastic; few fine and medium roots; common very fine and few fine pores; common moderately thick clay skins on faces of peds; common slickensides on faces of peds; 2 percent pebbles; strongly acid (pH 5.4); clear smooth boundary. (6 to 16 inches thick)
2Bt2--29 to 36 inches, yellowish red (5YR 4/8) clay, yellowish red (5YR 5/6) dry; faces of peds are red (2.5YR 4/8) and light brown (7.5YR 6.4) dry and red (2.5YR 4.6) and brown (7.5YR 5/4) moist; weak medium prismatic structure parting to moderate medium and coarse subangular blocky; extremely hard, very firm, sticky and very plastic; few fine and medium roots; common very fine and fine pores; common moderately thick clay skins on faces of peds; common slickensides on faces of peds; 2 percent pebbles; strongly acid (pH 5.4); clear smooth boundary. (0 to 18 inches thick)
2Bt3--36 to 43 inches, red (2.5YR 4/6) clay loam, red (2.5YR 5/6) dry; faces of peds are red (2.5YR 5/8) and light brown (7.5YR 6/4) dry, and red (2.5YR 4/8) and brown (7.5YR 5/4) moist; weak medium prismatic structure parting to moderate medium angular blocky; extremely hard, very firm, sticky and very plastic; few fine and medium roots; common very fine and fine pores; continuous moderately thick clay films on faces of peds and in pores; 5 percent soft pebbles; strongly acid (pH 5.4); clear smooth boundary. (0 to 15 inches thick)
2Bt4--43 to 50 inches, red (2.5YR 4/8) clay loam, red (2.5YR 4/6) dry; faces of peds are red (2.5YR 5/8) and light brown (7.5YR 6/4) dry and red (2.5YR 4/8) and light brown (7.5YR 6/4) moist; moderate medium and coarse angular blocky structure; extremely hard, very firm, slightly sticky and plastic; few fine roots; few very fine pores; continuous moderately thick clay films on faces of peds and in pores; 20 percent soft sandstone pebbles; strongly acid (pH 5/4); clear smooth boundary. (0 to 7 inches thick)
C--50 to 70 inches, red (10R 4/6) clay loam, red (2.5YR 5/6) dry; faces of peds are red (2.5YR 4/8) dry, and red (10R 4/6) moist; moderate medium and coarse subangular blocky structure; very hard, firm, slightly sticky and plastic; few very fine roots; 40 percent soft sandstone pebbles; strongly acid (pH 5.2).
TYPE LOCATION: Morgan County, Utah; 11 miles north and 2 miles west of Croydon on Herd Mountain at intersection of aircraft landing strips; about 240 feet south, and 2,000 feet west of the northeast corner of sec. 25, T. 6 N., R. 3 E.
RANGE IN CHARACTERISTICS: The upper 6 to 9 inches of the soil have moist value of less than 4 after mixing. The upper boundary of the 2Bt horizon occurs at depths of 13 to 24 inches. The combined thickness of the A and 2Bt horizon ranges from 50 to more than 60 inches over bedrock or underlying C horizon. The mean annual soil temperature at depth of 20 inches ranges from 41 to 44 degrees F. The mean summer soil temperature ranges from 54 to 59 degrees F. The soils are usually moist, but are dry for 30 to 45 days during the late summer. Rock fragments consist of rounded quartzite pebbles and cobbles, and range from 15 to 35 percent in the A horizon. The 2Bt horizon has 0 to 20 percent soft sandstone pebbles and cobbles.
The A1 horizon has hue of 10YR, 7.5YR or 5YR, value of 4 or 5 dry. 2 or 3 moist, and chroma of 2 through 4 dry, 2 or 3 moist. The A2 and A3 horizons have hue of 5YR, 7.5YR, or 10YR, value of 4 through 7 dry, 3 through 5 moist, and chroma of 3 through 6 dry, 2 through 6 moist and they have either moist chroma or moist value of 4 or more in all parts. This horizon ranges from medium acid to neutral.
The 2Bt horizon has hue of 2.5YR, 5YR or 7.5YR, value of 3 through 6 dry and moist, and chroma of 4 through 8 dry, 3 through 8 moist. Texture ranges from clay to silty clay or clay loam. Reaction ranges from strongly acid to slightly acid.
COMPETING SERIES: These are the Chedsey, Cramont (T), Harkness (T), Pagosa, Siesta, and Stovho series. Chedsey soils have a paralithic contact at a depth of 20 to 40 inches. Cramont and Harkness soils have hue of 10YR or yellower in the argillic horizon and have O horizons. Pagosa soils have A and B horizons and have solum thickness of less than 50 inches and are mainly 7.5YR or yellower. Siesta soils have basalt bedrock at depths of 35 to 45 inches and are neutral to moderately alkaline. Stovho soils have visible carbonates within the series control section.
GEOGRAPHIC SETTING: Herd soils are at elevations of 7,000 to 9,000 feet. They occur on mountain tops and ridges. Slopes range from 3 to 25 percent but are dominantly 3 to 15 percent. These soils formed in till from conglomerate of sandstone and quartzite over residuum weathered from sandstone. The climate is humid and the averge annual precipitation ranges from 25 to 35 inches. The mean annual temperature is 39 to 42 degrees F. The mean summer temperature is 52 to 57 degrees F., and the freeze-free period ranges from 70 to 65 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Charcol, Lucky Star, Moweba and Yence soils. Charcol soils have mollic epipedons more than 20 inches thick and have loamy-skeletal control sections. Lucky Star soils have mollic epipedons and loamy-skeletal control sections. Moweba soils have mollic epipedons more than 20 inches thick and mean summer temperatures of more than 59 degrees F. Yence soils have a clayey skeletal particle-size control section.
DRAINAGE AND PEREMABILITY: Well drained; slow to medium runoff; slow permeability.
USE AND VEGETATION: These soils are used for watershed, range, and wildlife habitat. The potential vegetation is mulesear dock, slender wheatgrass, mountain brome, yarrow and silver sagebrush.
DISTRIBUTION AND EXTENT: These soils occur in Weber and Morgan Counties, Utah. They are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Morgan Area, Morgan County, Utah, 1974.