LOCATION PAHSIMEROI IDEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, siliceous, frigid Xeric Haplocambids
TYPICAL PEDON: Pahsimeroi extremely gravelly loam on a south-facing fan terrace with a slope of 2 percent on rangeland. (Colors are for air-dry soil unless otherwise stated. The profile was described on October 23, 1979.)
A--0 to 5 inches; brown (10YR 5/3) extremely gravelly loam, dark brown (10YR 3/3) moist; weak very fine and fine platy structure; soft, very friable, slightly sticky and slightly plastic; common very fine and few fine and medium roots; many very fine tubular and interstitial pores; 40 percent pebbles and 20 percent cobbles; slightly alkaline (pH 7.4); clear wavy boundary. (3 to 6 inches thick)
Bw1--5 to 12 inches; yellowish brown (10YR 5/4) very gravelly coarse sandy loam, brown (10YR 4/3) moist; weak very fine granular structure; soft, very friable, slightly sticky and nonplastic; many very fine and common fine, medium and coarse roots; many very fine tubular pores; 40 percent pebbles, 15 percent cobbles; neutral (pH 7.2); clear wavy boundary. (6 to 14 inches thick)
Bw2--12 to 25 inches; yellowish brown (10YR 5/4) extremely cobbly loamy coarse sand, dark yellowish brown (10YR 4/4) moist; single grain; loose; many very fine and common fine and medium roots; common very fine tubular, and many very fine interstitial pores; 30 percent pebbles, 30 percent cobbles, and 5 percent stones; neutral (pH 7.1); gradual wavy boundary. (3 to 40 inches thick)
Bkq--25 to 60 inches; multicolored extremely cobbly coarse sand; single grain; loose; common very fine roots; common very fine tubular and common and many, very fine and fine interstitial pores; 30 percent pebbles, 30 percent cobbles, and 10 percent stones; lime and silica coats the undersides of coarse fragments; moderately alkaline (pH 8.0).
TYPE LOCATION: Lemhi County, Idaho; about 2.5 miles west of May, Idaho; 2,000 feet north and 950 feet east of the southwest corner, sec. 14, T. 15 N., R. 21 E.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 40 to 43 degrees F
Control section - percent clay 6 to 10
Rock fragments - 50 to 80 percent
Depth to sand and gravel (Bw2 horizon) - 10 to 20 inches
A horizon
Value - 5 or 6 dry, 3 to 5 moist
Chroma - 2 or 3, dry and moist
Bw1 horizon
Value - 5 or 6 dry, 3 to 5 moist
Chroma - 3 or 4, dry and moist
Texture - GRX-COSL, GRV-COSL
Rock fragments - 35 to 75 percent
Bw2 and Bkq horizons
Texture - CBX-COS, CBX-S, CBX-LCOS, GRX-LCOS, GRX-S
Rock fragments - 60 to 85 percent
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: Pahsimeroi soils are on outwash fans and fan terraces and have slopes of 2 to 20 percent. Elevations are 4,500 to 6,200 feet. The soils formed in mixed alluvium weathered from quartzite. The Climate is cold and moist in winter and spring and dry in summer. Average annual precipitation is 7 to 11 inches. Average summer temperature is 62 to 64 degrees F. Average annual temperature is 39 to 41 degrees F. Frost-free period is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dawtonia, Simeroi, Venum, Whitecloud, Whiteknob, and Zer. Dawtonia soils are on mountains and fan terraces and have an argillic horizon. Simeroi, Whitecloud, and Whiteknob soils are on fan terraces and have a calcic horizon. Venum soils are on mountains and have an argillic horizon. Zer soils are on mountains and fan terraces and have a calcic horizon.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow runoff; permeability is moderate over very rapid.
USE AND VEGETATION: Rangeland. It has potential for cropland. Vegetation is mainly Wyoming big sagebrush and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: East central Idaho. This series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lemhi County, Idaho, 1999.
REMARKS: Diagnostic features recognized in this pedon are:
Ochric epipedon
Cambic horizon - The zone from 5 to 12 inches (Bw1 horizon).
The particle-size control section is the zone from 10 to 40 inches (Bw1, Bw2, and part of the Bkq horizons).