LOCATION HARPOLE UT+WY

Established Series
REV: DAL/RLM/SJJ
03/2017

HARPOLE SERIES

The Harpole series consists of very deep, well drained, moderately slowly permeable soils that formed in slope alluvium or colluvium derived dominantly from sedimentary and igneous rocks. Harpole soils are on mountainsides and have slopes of 10 to 60 percent. Average annual precipitation is about 18 inches (457 mm); and the mean annual temperature is about 43 degrees F. (6.1 C).

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Alfic Argiustolls

TYPICAL PEDON: Harpole very cobbly loam (rangeland), in a map unit of Harpole very cobbly loam, 25 to 60 percent slopes. (Colors are for air-dry soil unless otherwise stated.)

A1--0 to 5 cm; brown (10YR 4/3) very cobbly loam, dark brown (7.5YR 3/2) moist; weak medium platy structure; soft, very friable; common very fine and fine roots; common fine and medium pores; 15 percent gravel, 20 percent cobbles, 5 percent stones; slightly alkaline (pH 7.6); abrupt smooth boundary. (5 to 10 cm thick)

A2--5 to 25 cm; brown (7.5YR 4/4) cobbly loam, dark brown (7.5YR 3/3) moist; weak medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; common very fine, fine, and medium roots; common fine pores; 5 percent gravel, 15 percent cobbles; slightly alkaline (pH 7.8); clear smooth boundary. (20 to 30 cm thick)

Bw--25 to 38 cm; brown (7.5YR 5/4) cobbly sandy loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; few medium and common fine roots; few fine pores; 15 percent gravel, 10 percent cobbles; slightly alkaline (pH 7.8); clear wavy boundary. (10 to 15 cm thick)

Bt1--38 to 79 cm; reddish brown (5YR 5/4) very cobbly sandy clay loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, sticky and slightly plastic; few medium and common fine roots; few fine pores; few moderately thick clay films on faces of peds; 20 percent gravel, 15 percent cobbles, 5 percent stones; slightly alkaline (pH 7.8); clear wavy boundary. (25 to 56 cm thick)

Bt2--79 to 97 cm; reddish brown (5YR 5/4) very cobbly sandy clay loam, reddish brown (5YR 4/4) moist; weak medium subangular blocky structure; soft, friable, sticky and slightly plastic; few very fine roots; few thin clay films on faces of peds; 20 percent gravel, 20 percent cobbles, 5 percent stones; moderately alkaline (pH 8.0); clear smooth boundary. (0 to 33 cm thick)

C--97 to 152 cm; yellowish red (5YR 5/6) very cobbly loamy sand, reddish brown (5YR 4/4) moist; massive; soft, friable; few fine roots; 15 percent gravel, 20 percent cobbles, 10 percent stones; moderately alkaline (pH 8.0).

TYPE LOCATION: San Juan County, Utah. About 4 miles north of LaSal, 1,800 feet north and 700 feet west of the southeast corner of sec. 15, T. 28 S., R. 24 E.

RANGE IN CHARACTERISTICS: The mollic epipedon is 25 to 40 cm thick. Thickness of the solum is 50 to 100 cm. Mean annual soil temperature is 43 to 47 degrees F. (6 to 8 C.) These soils are moist 50 to 60 percent of the time when the soil temperature at a depth of 50 cm is more than 41 degrees F. (5 C). They are moist in some part for 50 to 60 consecutive days or more in the 4 months following the summer solstice. The transitional horizon between the surface and the argillic horizon does not have to be a Bw, it can also be an AB, BA, BE or E.

The A horizon has hue of 7.5YR or 10YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 2 or 3 dry or moist. It is neutral or slightly alkaline.

The Bt horizon has hue of 5YR or 7.5YR, value 5 dry, 4 moist, and chroma 4 to 6 dry or moist. It is typically very gravelly sandy clay loam or very cobbly sandy clay loam. The weighted average of this horizon is 35 to 60 percent rock fragments, and 20 to 27 percent clay. It is slightly alkaline or moderately alkaline.

The C horizon has hue of 5YR or 7.5YR. It is very cobbly loamy sand or extremely gravelly sandy loam. The C horizon is slightly alkaline or moderately alkaline.

COMPETING SERIES: These are the Cosey and Isolation series. Cosey soils receive more precipitation (22 to 30 inches), and are 7.5YR or yellower. Isolation soils have less than 18 percent clay in the particle size control section.

GEOGRAPHIC SETTING: Harpole soils are on mountainsides. Elevation ranges from 7,700 to 8,900 feet (2,350 to 2,715 m). Slope ranges from 10 to 60 percent. These soils formed in slope alluvium or colluvium weathered from intermediate igneous and sedimentary rocks. Mean annual temperature is 41 to 45 degrees F. (5.0 to 7.2 C) and the average annual precipitation is 16 to 22 inches (406 to 560 mm). The freeze-free period is about 70 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Broad Canyon, Hangdo, Herm, Kunz, and Skylick soils. The Broad Canyon and Skylick soils are cryic. The Hangdo, Herm, Kunz, and Skylick soils have less than 35 percent rock fragments in the particle size control section. The Kunz soils do not have a mollic epipedon. The Herm soils have more than 35 percent clay in the particle size control section.

DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability (0.2 to 0.6 in/hr).

USE AND VEGETATION: Used mainly for rangeland and wildlife habitat. The potential vegetation is mainly Gambel oak, Snowberry, Utah serviceberry, Mountain big sagebrush, Mountain brome, and Bluegrass.

DISTRIBUTION AND EXTENT: LRR E, MLRAs 47, 48A. Eastern and Northeastern Utah. The series is not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Canyonlands Area, San Juan County, Utah, 1983. Named after Harpole Mesa.

REMARKS: Diagnostic horizons and features recognized in this profile.
Mollic Epipedon: The zone between 0 and 25 cm. (A1, A2)
Alfic feature: The zone between 25 and 38 cm. (Bw)
Argillic Horizon: the zone between 38 and 97 cm. (Bt1, Bt2)

When first established, the classification was Typic Argiborolls.

National Cooperative Soil Survey
U.S.A.