LOCATION MOUNTAINVILLE UTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Calciargidic Argixerolls
TYPICAL PEDON: Very stony sandy loam - rangeland (Colors are for dry soil unless otherwise noted.)
Al--0 to 4 inches; brown (10YR 5/3) very stony sandy loam, dark brown (10YR 3/3) moist; weak medium platy structure that parts to weak fine granular structure; slightly hard, friable, nonsticky, slightly plastic; common very fine, few fine roots; few very fine pores; 10 to 25 percent of surface is covered by stones or cobbles; moderately calcareous, lime is disseminated; slightly alkaline (pH 7.8); abrupt smooth boundary. (2 to 4 inches thick)
A2--4 to 11 inches; brown (10YR 5/3) very stony sandy loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; few fine and common very fine roots; few very fine and fine pores; 50 percent coarse fragments dominantly cobbles or stones; moderately calcareous, lime is disseminated; moderately alkaline (pH 8.2); clear smooth boundary. (5 to 7 inches thick)
BA--11 to 20 inches; brown (10YR 5/3) stony loam, dark brown (7.5YR 3/2) moist; moderate fine granular structure; hard, friable, slightly sticky, plastic; common fine and few medium roots; few very fine, fine and medium pores; 40 percent coarse fragments, dominantly stones; noncalcareous; slightly alkaline (pH 7.8); clear smooth boundary. (7 to 9 inches thick)
Bt1--20 to 31 inches; brown (7.5YR 5/4) very stony sandy clay loam, brown (7.5YR 4/4) moist; moderate medium angular blocky structure; very hard, firm, sticky, plastic; few fine, very fine and medium roots; common very fine, few fine pores; few faint clay films; 50 percent coarse fragments, dominantly stone; slightly calcareous, lime is coated on coarse fragments, soil mass is non-calcareous; slightly alkaline (pH 7.8); gradual smooth boundary. (9 to 12 inches thick)
Bt2--31 to 38 inches; brown (7.5YR 5/4) very stony sandy clay loam, brown (7.5YR 4/4) moist; moderate medium angular blocky structure; very hard, firm, sticky, plastic; common fine, few very fine and medium roots; few fine and very fine pores; few distinct clay films; 70 percent coarse fragments, dominantly cobbles and stones; slightly calcareous, lime is coated on coarse fragments, soil mass is noncalcareous; slightly alkaline (pH 7.8); abrupt wavy boundary. (6 to 9 inches thick)
Ckl--38 to 56 inches; very pale brown (10YR 8/3) very stony loam, pale brown (10YR 6/3) moist; massive; hard, friable, slightly sticky, plastic; few fine and very fine roots; common very fine, few fine pores; 60 percent coarse fragments mainly stones; strongly calcareous, lime is disseminated, coated on coarse fragments, in veins and accumulated in soft rounded masses; strongly alkaline (pH 8.8); abrupt wavy boundary. (7 to 9 inches thick)
Ck2--56 to 64 inches; very pale brown (10YR 7/3) very stony light loam, brown (10YR 5/3) moist; massive; hard, friable, slightly sticky, slightly plastic; few very fine roots; few fine and very fine pores; 50 percent coarse fragments, mainly cobbles and stones; strongly calcareous, lime is disseminated and in veins; very strongly alkaline (pH 9.2).
TYPE LOCATION: Sanpete County, Utah; about 3 miles northeast of Mount Pleasant, between North Creek and Mountainville; about 1,600 feet south and 2,800 feet east of the NW corner of sec. 31, T.14S., R.4E.
RANGE IN CHARACTERISTICS: The soil is 22 to 38 inches thick. Coarse fragments in the control section range from 35 to 70 percent and are mainly stone. The mean annual soil temperature at 20 inches ranges from 47 to 49 degrees F. The mean summer soil temperature ranges from 62 to 67 degrees F. In more than 7 out of 10 years the soils are dry in the moisture control section for 60 to 80 consecutive days between June 21 and September 21, and are dry in the moisture control section 50 to 55 percent of the time. Soil temperature at 20 inches is above 41 degrees F. in most years. The moisture control section is moist for 60 to 70 consecutive days during the 120 days after the winter solstice.
The A horizon has hue of 10YR or 7.5YR, value of 4 and 5 dry, 2 or 3 moist, and chroma of 2 or 3. It is neutral to moderately alkaline.
The Bt horizon has hue of 10YR or 7.5YR, value of 5 or 6 dry, 3 or 4 moist, and chroma of 3 or 4. It ranges from stony or very stony sandy clay loam to stony or very stony clay loam, with 35 to 80 percent coarse fragments, dominantly stone size. This horizon has few faint to common distinct clay films on faces of peds and on coarse fragments.
The Ck horizon has hue of 10YR or 2.5Y, value of 7 or 8 dry, 5 or 6 moist, and chroma of 3 or 4. It ranges from stony or very stony sandy clay loam to stony or very stony fine sandy loam, with 35 to 75 percent coarse fragments, mainly stone size. This horizon is moderately to strongly alkaline, strongly to very strongly calcareous.
COMPETING SERIES: These are the Broad, Butterfield, Collard, Holmes, Horrocks, Hoskin, Red Butte, Ridd, Tollgate and Walsey (T), series. Broad, Holmes, Horrocks and Hoskin soils have mean annual soil temperature of less than 47 degrees F. and are usually moist. Butterfield and Ridd soils are moist in the moisture control section more than one-half of the time soil temperature is above 41 degrees F. Collard and Tollgate soils lack calcic horizons. Red Butte soils lack stones or boulders in the control section. Walsey soils have a mean annual soil temperature of 54 to 58 degrees F. and and have a depth to bedrock of 20 to 40 inches.
GEOGRAPHIC SETTING: The Mountainville soils are on gently to strongly sloping alluvial fans at elevations of 5,600 to 6,700 feet. They formed in alluvium from sandstone, quartzite and limestone. The climate is dry subhumid. Mean annual temperature ranges from 45 to 47 degrees F. Mean summer temperatures are 60 to 65 degrees F. Average annual precipitation ranges from 12 to 14 inches. Frost-free period is 110 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Donnardo, Doyce, Lisade and Pavant soils. Doyce soils lack stones or boulders in The B2t horizon. Lisade, Pavant and Donnardo soils lack argillic horizons. Pavant soils have petrocalcic horizons.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used for range and irrigated pasture. Principal native vegetation is big sagebrush, bluebunch wheatgrass, cheatgrass, yellowbrush and rubber rabbitbrush.
DISTRIBUTION AND EXTENT: Central Utah. The soils are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Sanpete Area, Utah, 1971.
REMARKS: The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data.