LOCATION MCPHIE UTEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Alfic Argixerolls
TYPICAL PEDON: McPhie sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
Al--0 to 7 inches; very dark grayish brown (10YR 3/2) sandy loam, very dark brown (10YR 2/2) moist; moderate coarse granular structure; slightly hard, friable, nonsticky, nonplastic; common fine and medium and few large roots; few fine medium and large pores; slightly acid (pH 6.1); clear smooth boundary. (2 to 7 inches thick)
A2--7 to 12 inches; dark grayish brown (10YR 4/2) light loam, very dark brown (10YR 2/2) moist; weak medium and fine subangular blocky structure that parts to weak medium granular structure; slightly hard, friable, nonsticky, slightly plastic; common medium and few fine and large roots; few fine and medium pores; strongly acid (pH 5.5); clear wavy boundary. (4 to 6 inches thick)
E--12 to 24 inches; grayish brown (10YR 5/2) gravelly sandy loam, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure that parts to weak fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; clean sand grains; many large, common medium and few fine roots; many fine common medium and large pores; slightly acid (pH 6.2); gradual wavy boundary. (6 to 12 inches thick)
BE--24 to 30 inches; brown (10YR 5/3) cobbly sandy loam, brown (10YR 4/3) moist; the A portion of the horizon has ped coatings of pale brown (10YR 6/3) and brown (10YR 4/3) when moist; weak coarse subangular blocky structure that parts to weak fine subangular blocky structure; hard, firm, sticky, plastic; common faint clay films in pores; few fine and medium roots; few fine pores; clean sand or silt grains; moderately acid (pH 6.0) gradual wavy boundary. (3 to 20 inches thick)
Bt1--30 to 38 inches; brown (10YR 5/3) cobbly light loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; hard, firm, sticky, plastic; common faint clay films, mainly in pores; few fine and medium roots; few fine pores; moderately acid (pH 5.8); gradual wavy boundary. (3 to 20 inches thick)
Bt2--38 to 55 inches; brown (10YR 5/3) cobbly light loam, brown (10YR 4/3) moist; moderate coarse subangular blocky structure that parts to medium and fine subangular blocky structure; hard, firm, sticky, plastic; common distinct clay films, mainly in pores; few fine and medium roots; few medium and fine pores; moderately acid (pH 5.9); gradual wavy boundary. (O to 27 inches thick)
Bt3--55 to 60 inches; brown (7.5YR 5/4) cobbly sandy loam, dark brown (7.5YR 3/3) moist; weak medium subangular blocky structure; hard, firm, sticky, plastic; common faint and few distinct clay films; few medium roots; few fine pores; neutral (pH 6.6).
TYPE LOCATION: Utah County, Utah; about 2 miles north of Alpine in Fort Canyon; about 1/2 mile west of last farm house; 3,000 feet west and 1,600 feet south of NE corner of sec. 12, T. 4 S., R. 1 E.
RANGE IN CHARACTERISTICS: The soils are more than 4 feet thick to the bottom of the Bt horizons. The soils contain 20 to 35 percent rock fragments throughout. The mollic epipedons are less than 20 inches thick and organic matter decreases regularly or reaches levels of less than 0.5 percent within depth of 50 inches. Mean annual soil temperature at depth of about 20 inches is less than 47 degrees F., average summer soil temperature is 60 to 65 degrees F. Clay mineralogy is mixed but vermiculite is a significant component. The soils are not usually dry, but are dry in the 7 to 20 inch section for more than 45 consecutive days. They range from strongly acid to neutral.
The A horizon has value of 3 through 5 dry, 2 or 3 moist, and chroma of 1.5 or 2. It is sandy loam or cobbly sandy loam.
The E horizon has value of 5 or 6 dry and chroma of 2 or 3. It is sandy loam with 20 to 50 percent angular gravel and cobbles.
The BE horizon has hue of 7.5YR or 10YR, value of 5 or 6 dry, 3 or 4 moist, and chroma of 3 or 4. It is loam or sandy loam and contains 15 to 30 percent rock fragments.
The Bt horizons have hue of 7.5YR or 10YR, value of 5 or 6 dry, 3 or 4 moist, and chroma of 3 or 4. It is loam or fine sandy loam, with more than 15 percent sand coarser than very fine sand and contains 20 to 50 percent cobble and gravel. This horizon has weak to strong angular and subangular blocky structure. The lower Bt horizon has hue of 7.5YR or 10YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 3 through 6. It is loam or sandy loam, with 30 to 50 percent angular gravel and cobbles.
COMPETING SERIES: This is the Gappmayer series. Gappmayer soils have more than 35 percent rock fragments in the control section.
GEOGRAPHIC SETTING: McPhie soils are at elevations of 5,000 to 7,200 feet on strongly sloping to very steep mountain slopes with slope gradients of 6 to 60 percent. The lower elevations are dominantly on northerly facing slopes. The soils formed in alluvium or colluvium, derived from intermediate igneous, granite, and minor amounts of sedimentary parent rocks. The climate is moist subhumid, having a mean annual temperature of 45 degrees F, and average summer temperature of 60 to 65 degrees F, and an average annual precipitation of 20 to 25 inches. Growing season is 80 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Henefer and Van Wagoner soils. Henefer soils lacks A2 horizons and have Bt horizons with more than 35 percent clay. Van Wagoner soils are shallow lithosolic soils that lack A2 and Bt horizons.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; moderate permeability.
USE AND VEGETATION: Rangeland. Native vegetation is big sagebrush, oakbrush, maple, snowberry, perennial grasses, associated forbs and scattered scrub aspen and Douglas-fir.
DISTRIBUTION AND EXTENT: These soils are in foothill and mountain areas of northern Utah. They are inextensive, but locally important for rangeland, watershed, and wildlife habitat.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Heber Valley Area, Utah, 1972.