LOCATION OXHEAD IDEstablished Series
TAXONOMIC CLASS: Ashy, glassy, frigid Vitrixerandic Haplocalcids
TYPICAL PEDON: Oxhead gravelly loam - on a 3 percent east to northeast- facing slope at 6,150 feet elevation in rangeland. (Colors are for dry soil unless otherwise noted. When described on May 27, 1981, the soil was dry to 13 inches and moist below this depth.)
A--0 to 3 inches; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine and few medium and coarse roots; many very fine and fine interstitial pores; 15 percent pebbles; slightly alkaline (pH 7.6); clear smooth boundary. (2 to 4 inches thick)
Bw--3 to 9 inches; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; slightly hard, firm, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine interstitial pores; 10 percent pebbles; slightly effervescent; moderately alkaline (pH 7.9); clear wavy boundary. (2 to 6 inches thick)
Bk1--9 to 14 inches; very pale brown (10YR 7/4) gravelly loam, yellowish brown (10YR 5/4) moist; weak medium subangular blocky structure parting to moderate thin laminae; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine and few medium roots; many very fine and fine interstitial pores; 15 percent fine pebbles with occasional lime coats on undersides of rock fragments; violently effervescent; moderately alkaline (pH 8.2); clear smooth boundary. (4 to 6 inches thick)
Bk2--14 to 21 inches; very pale brown (10YR 8/3) gravelly loam, light yellowish brown (10YR 6/4) moist; massive; hard, firm, slightly sticky and nonplastic; few medium roots; many very fine and fine interstitial pores; 20 percent pebbles; horizon is compacted and most roots run horizontally along top of horizon; violently effervescent; moderately alkaline (pH 8.3); abrupt wavy boundary. (6 to 10 inches thick)
Bk3--21 to 30 inches; white (10YR 8/2) very fine sandy loam, pale brown (10YR 6/3) moist; weak coarse subangular blocky structure; hard, firm, nonsticky and nonplastic; few very fine and fine roots; many fine interstitial pores; 5 percent pebbles; violently effervescent; strongly alkaline (pH 8.5); clear wavy boundary. (6 to 12 inches thick)
Bk4--30 to 56 inches; very pale brown (10YR 7/4) fine sandy loam, yellowish brown (10YR 5/6) moist; moderate medium laminae parting to strong thin laminae; slightly hard, friable, nonsticky and nonplastic; few very fine and fine roots; many very fine and fine interstitial pores; 5 percent pebbles; horizon is very compacted and stops about 75 percent of the roots; root mat at the top of horizon; violently effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (15 to 30 inches thick)
Bk5--56 to 61 inches; very pale brown (10YR 8/4) fine sandy loam, light yellowish brown (10YR 6/4) moist; strong very thin laminae parting to strong fine angular blocky; hard, firm, slightly sticky and slightly plastic; few very fine roots; few fine interstitial pores; 2 percent pebbles; violently effervescent; strongly alkaline (pH 8.5).
TYPE LOCATION: Lemhi County, Idaho; about 8 miles from Leadore, Idaho; along road from State highway 28 to Oxbow Ranch; about 500 feet south and 1600 feet east from the northwest corner sec. 6, T. 14 N., R. 27 E. Latitude - 44 degrees, 34 minutes, 42 seconds North; Longitude - 113 degrees, 17 minutes, 15 seconds West.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 39 to 41 degrees F.
Glass content - 30 to 50 percent
Depth to calcic horizon - 5 to 15 inches
Control section - percent average total clay - 10 to 17
Coarse fragments - 5 to 30 percent
A horizon
Value - 4 through 6 dry, 3 or 4 moist
Chroma - 2 or 3 dry and moist
Bw horizon
Value - 6 or 7 dry, 3 through 6 moist
Chroma - 3 or 4 dry and moist
Coarse fragments - 0 to 20 percent
Texture - L or GR-L
Bk horizon
Value - 6 through 8 dry, 5 through 7 moist
Chroma - 2 through 6 dry and moist
Calcium carbonate equivalent - 25 to 40 percent
Coarse fragments - 0 to 25 percent
Texture - GR-L, FSL, or L
COMPETING SERIES: These are the Holsine, Lariat, Lidy, Malm, Matheson, Sparmo, and Voltage series. Holsine soils lack B horizons and have extremely gravelly nonconforming layer near the surface. Lariat soils are moderately deep to fractured sandstone. Lidy and Sparmo soils are moderately deep to extremely gravelly material. Malm soils have bedrock at 20 to 40 inches. Matheson soils have basalt bedrock at 46 inches and less than 5 percent rock fragments. Voltage soils have annual soil temperatures of 45 to 47 degrees F. and have less than 5 percent rock fragments.
GEOGRAPHIC SETTING: Oxhead soils are on terraces and have slopes of 2 to 8 percent. Elevations are 6,000 to 6,900 feet. The soils formed in uplifted lacustrian sediments influenced by volcanic ash. The climate is cold and moist in winter and spring and dry in summer. Average annual precipitation is 8 to 11 inches. Average summer temperature is 62 to 64 degrees F and average annual temperature is 37 to 39 degrees F. Frost-free period is 50 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Escarlo, Heathcoat, Whiteknob, and Wiggleton soils. Escarlo and Heathcoat soils are on hills and have mollic epipedons. Whiteknob soils are on fan terraces and have sandy-skeletal control sections. Wiggleton soils are on outwash fans and fan terraces and have mollic epipedons and sandy-skeletal control sections.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; moderate permeability.
USE AND VEGETATION: Rangeland. Vegetation is mainly Wyoming big sagebrush and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: East-central Idaho; this soil is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Lemhi County, Idaho, 1999.
ADDITIONAL DATA: Type location S82ID-59-002; 82P684.
REMARKS: Diagnostic features recognized in this pedon are:
Ochric epipedon
Calcic horizon - the zone from 9 to 61 inches (Bk horizons)
The particle-size control section is the zone from 10 to 40 inches (part of the Bk1 horizon, the Bk2, Bk3, and part of the Bk4 horizons)