LOCATION CHARCOL UTEstablished Series
SOIL FAMILY: Loamy-skeletal, mixed Cryic Pachic Paleborolls.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Pachic Palecryolls
TYPICAL PEDON: Charcol gravelly sandy loam, rangeland. (Colors are for moist soil unless otherwise noted.)
A11--0 to 13 inches; very dark grayish brown (10YR 3/2) gravelly sandy loam, brown (7.5YR 4/2) dry; weak fine granular structure; soft, very friable, slightly sticky and slightly plastic; many fine and few medium and coarse roots; 40 percent gravel; slightly acid (pH 6.4); clear wavy boundary. (6 to 18 inches thick)
A12--13 to 21 inches; dark brown (7.5YR 3/3) gravelly sandy loam, brown (7.5YR 5/4) dry; weak medium subangular blocky structure that parts to weak fine granular; slightly hard, friable, slightly sticky and slightly plastic; common fine, and few medium and coarse roots; 35 percent gravel and 10 percent cobbles; slightly acid (pH 6.3); gradual irregular boundary. (6 to 18 inches thick)
A21--21 to 30 inches; dark red (2.5YR 3/6) very gravelly sandy loam, light reddish brown (5YR 6/4) dry; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; common fine and few medium roots; 10 percent cobbles and 50 percent gravel; slightly acid (pH 6.3); gradual wavy boundary. (8 to 18 inches thick)
A22--30 to 38 inches; dark red (2.5YR 3/6) very gravelly light sandy loam, light reddish brown (2.5YR 6/4) dry; weak fine subangular blocky structure; slightly hard, very friable, nonplastic; few fine and medium roots; 10 percent cobbles, 55 percent gravel; slightly acid (pH 6.2); clear smooth boundary. (0 to 20 inches thick)
A&B--38 to 44 inches; about 60 percent A2 as described in A22 above and 40 percent B2t horizon as described in B2t below; gradual smooth boundary. (0 to 22 inches thick)
B2t--44 to 54 inches; dark red (10R 3/6) gravelly heavy loam, red (2.5YR 4/6) dry; moderate medium subangular blocky structure; very hard, firm, sticky and slightly plastic; few fine and medium roots; common fine and very fine pores; many thin clay films on faces of peds; 35 percent gravel; slightly acid (pH 6.2); abrupt smooth boundary. (8 to 25 inches thick)
C--54 to 62 inches; dark red (2.5YR 3/6) very gravelly light sandy loam, red (2.5YR 5/6) dry; single grained; loose, nonsticky and nonplastic; few fine roots; 55 percent gravel; slightly acid (pH 6.2).
TYPE LOCATION: Morgan County, Utah; 10 miles north and 1 mile east of Lost Creek Dam; 1,400 feet east and 400 feet south of W1/4 corner of sec. 22, T.7N., R.5E.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 20 to 34 inches thick. The upper boundary of the B2t horizon is 40 to 60 inches or more below the surface. The combined thickness of the A1, A2 and B2t horizons ranges from 48 to 60 inches or more. The 10- to 40-inch control section contains 35 to 60 percent gravel, cobbles and stones. The mean annual soil temperature at depths of 20 inches ranges from 42 degrees to 47 degrees F. The mean summer soil temperature ranges from 57 degrees 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 or sandstone pebbles and cobbles, and range from 20 to 50 percent in the A1 horizon, 45 to 70 percent in the A2 horizon and 35 to 70 percent in the B2t horizon.
The A1 horizon has hue of 10YR, 7.5YR, or 5YR, value of 2 through 5 dry, 2 or 3 moist, and chroma of 2 through 4 dry and 2 or 3 moist. It ranges from gravelly sandy loam or loam, gravelly loam, cobbly loam or very cobbly loam or gravelly fine sandy loam to very stony fine sandy loam. This horizon is medium acid to neutral and is 20 to 34 inches thick.
The A2 horizon has hue of 7.5YR, 5YR, or 2.5YR, value of 5 through 7 dry, and 3 through 5 moist, and chroma of 3 through 6 dry and 4 through 6 moist. It ranges from cobbly or gravelly, or very cobbly, or very gravelly loam, or sandy loam, to very cobbly loamy sand. This horizon is slightly or medium acid, and is 10 to 35 inches thick.
The B2t horizon has dominant hue of 2.5YR or 10R. Value is 4 through 8 dry and 4 through 6 moist. This horizon ranges from gravelly or cobbly, or very gravelly or very cobbly clay loam, or gravelly sandy loam to gravelly, very gravelly or very cobbly sandy clay loam. It has weak through strong, fine through coarse subangular blocky structure. Clay films are common to many, thin to moderately thick. The B2t horizon is slightly acid or medium acid.
COMPETING SERIES: This is the Flygare series. Flygare soils have hue of 10YR, 7.5YR or 5YR in the B2t horizon.
GEOGRAPHIC SETTING: Charcol soil are at elevations of 7,000 to 8,500 feet. They occur on east, south and west-facing mountain slopes. Slopes range from 12 to 50 percent. These soils formed in residuum and colluvium from conglomerate, quartzite and sandstone. The climate is humid, and the average annual precipitation ranges from 22 to 35 inches. The mean annual temperature is 40 degrees to 45 degrees F. The mean summer temperature is 55 degrees to 57 degrees F., and the frost-free period ranges from 40 to 70 days.
ASSOCIATED SOILS: These are the Condie, Ercan, Lucky Star, Moweba, and St. Marys soils. Condie soils lack mollic epipedons. Ercan soils have mollic epipedons less than 20 inches thick and have less than 20 percent rock fragments in the B2t horizon. Lucky Star soils have mollic epipedons less than 20 inches thick. Moweba and St. Marys soils lack argillic horizons and have mean summer temperature of more than 59 degrees F.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; moderate permeability.
USE AND VEGETATION: These soils are used for watershed, range and wildlife habitat. The present vegetation is big sagebrush, snowberry, bearded wheatgrass, ceanothus, lupine, balsamroot, basin wildrye, and slender wheatgrass.
DISTRIBUTION AND EXTENT: These soils occur in Northern Utah. They are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Morgan Area, Morgan County, Utah, 1974.