LOCATION IPSON UT+CO WY

Established Series
Rev. MM/JB/JWB
03/2011

IPSON SERIES

The Ipson series consists of very deep, well drained soils that formed in colluvium and alluvium derived from basic and intermediate igneous rocks. Ipson soils occur on mountain slopes and alluvial fans and have slopes of 1 to 50 percent. The average annual precipitation is about 305 mm (12 inches) and the mean annual air temperature is about 6.7 degrees C (44 degrees F

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

TYPICAL PEDON: Ipson very cobbly loam - rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 6 inches (0 to 15 cm); brown (10YR 5/3) very cobbly loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common fine, few medium roots; few fine and medium pores; 15 percent gravel, 20 percent cobbles and 5 percent stones; neutral (pH 7.3); clear smooth boundary. (3 to 8 inches (8 to 20 cm) thick)

Bt--6 to 14 inches (15 to 36 cm); brown (10YR 4/3) very gravelly loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine, medium, and coarse roots; few fine and medium pores; few thin clay films; 25 percent gravel, 15 percent cobbles; slightly alkaline (pH 7.4); abrupt smooth boundary. (6 to 18 inches (15 to 46 cm) thick)

Bk1--14 to 25 inches (36 to 64 cm); very pale brown (10YR 7/3) very gravelly loam, pale brown (10YR 6/3) moist; weak medium subangular blocky structure; weakly cemented; friable, slightly sticky and slightly plastic; few fine medium and coarse roots; few fine pores; 25 percent gravel, 10 percent cobbles; violently effervescent; strongly alkaline (pH 8.6); gradual wavy boundary.

Bk2--25 to 36 inches (64 to 91 cm); very pale brown (10YR 7/3) very gravelly sandy loam, brown (10YR 5/3) moist; massive; hard, friable, slightly sticky and slightly plastic; 25 percent gravel and 10 percent cobbles; violently effervescent; strongly alkaline (pH 8.8); clear wavy boundary.

C--36 to 60 inches (91 to 152 cm); light gray (10YR 7/2) very gravelly sand, dark grayish brown (10YR 4/2) moist; single grain; loose; few fine roots; few fine pores; 40 percent gravel, 20 percent cobbles; strongly effervescent; moderately alkaline (pH 8.4).

TYPE LOCATION: Garfield County, Utah; 11 miles north and 10 miles east of the Bear Valley Highway U. S. 89 Junction; about 1,600 feet west and 1,600 feet south of the NE corner of section 16, T. 31 S., R. 3 W.; USGS Mount Dutton 7.5 minute quadrangle; lat. 38 degrees 7 minutes 0.5 seconds N. and long. 112 degrees 12 minutes 6.0 seconds W., NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Dry in all parts 75 to 90 days in winter and spring; dry in all parts 40 to 50 percent of the time the soil is above 41 degrees F (5 degrees C). Ustic soil moisture regime bordering on aridic.
Mean annual soil temperature: 6.1 to 7.8 degrees C (43 to 46 degrees F)
Mean summer soil temperature: 15.6 to 17.2 degrees C (60 to 63 degrees F)
Thickness of mollic epipedon: 7 to 14 inches (18 to 36 cm)

Particle-size control section (weighted average):
Clay content: 20 to 35 percent
Rock fragments: 35 to 50 percent; fragment lithology is basic and intermediate igneous rocks.

A horizon:
Value: 4 or 5 dry
Chroma: 2 or 3 dry or moist
Reaction: neutral or slightly alkaline

Bt horizon:
Hue: 10YR or 7.5YR
Value: 4 through 6 dry,3 or 4 moist
Chroma: 2 or 3 moist or dry
Texture: very gravelly loam, very cobbly loam, very gravelly clay loam or very cobbly clay loam
Clay percent: 20 to 35 percent
Rock fragments: 35 to 50 percent
Reaction: neutral of slightly alkaline

Bk horizons:
Value: 5 through 8 dry, 4 through 6 moist
Chroma: 2 or 3 dry or moist
Texture: Very gravelly loam, extremely gravelly loam, very gravelly sandy loam or extremely gravelly sandy loam
Rock fragments: 35 to 80 percent
Reaction: moderately alkaline or strongly alkaline
Effervescence: strong or violent

C horizon:
Value: 6 through 8 dry, 4 through 6 moist
Chroma: 2 or 3
Texture: very gravelly or extremely gravelly sand to very gravelly or extremely gravelly loam or very gravelly sandy loam or extremely gravelly sandy loam
Rock fragments: 35 to 80
Reaction: moderately alkaline or strongly alkaline
Effervescence: slight or strong

COMPETING SERIES: These are the Circleville, Dacore, Dullknife, Nebies, Sieben, Uracca and Widtsoe series.
Circleville soils are moderately deep over bedrock.
Dacore soils have aridic soil moisture regimes and Btk horizons.
Dullknife soils are moderately deep over limestone bedrock.
Nebies and Sieben soils are not dry in all parts 75 to 90 days in winter and spring.
Uracca soils have fragments that are mostly granite, gneiss and mica schist in the lower part.
Widtsoe soils are not adequately separated and should be reviewed for possible correlation.

GEOGRAPHIC SETTING:
Elevation: of 6,500 to 9,020 feet (1,981 to 2,749 m).
Landform: mountain slopes and alluvial fans
Slope: 1 to 60 percent.
Parent material: colluvium, slope alluvium and alluvium weathered from basic and intermediate igneous rocks.
Climate: semiarid
Average annual precipitation: 12 to 16 inches (305 to 406 mm).
Mean annual temperature: is 39 to 45 degrees F (3.9 to 7.2 degrees C)
Frost-free period: 70 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ashuelot, Brownsto and Tridell soils. Ashuelot soils have a petrocalcic horizon. Brownsto soils lack a mollic epipedon and an argillic horizon. Tridell soils lack an argillic horizon.

DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: The soils are used for rangeland, woodland, and wildlife habitat. The native vegetation is pinyon pine, Utah juniper, big sagebrush, blue grama and Indian ricegrass.

DISTRIBUTION AND EXTENT: South-central Utah, Colorado, and Wyoming. MLRA 47, 48A. The series is moderately extensive, with 123,637 acres to date.

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

SERIES ESTABLISHED: Panguitch Area, Garfield County, Utah, 1985.

REMARKS: in the future the landform will be kept to alluvial fans. The parent material will be alluvium. Ipson will not be used in Wyoming; and Colorado with sandstone parent material.
Classified according to the Keys to Soil Taxonomy Tenth Edition, 2006.

National Cooperative Soil Survey
U.S.A.