LOCATION OLEO IDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Vitrandic Haplocryalfs
TYPICAL PEDON: Oleo ashy silt loam, supporting a lodgepole pine/grouse whortleberry plant community, woodland; on a southwest slope of 5 percent; about 7,850 feet elevation. (Colors are for air dry soil unless otherwise noted.)
0i--0 to 1 inch; forest litter of needles, twigs and leaves; abrupt smooth boundary. (1/2 to 2 inches thick)
A1--1 to 3 inches; dark grayish brown (10YR 4/2) ashy silt loam, very dark brown (10YR 2/2) moist; weak coarse platy structure parting to weak very fine granular; soft, very friable, nonsticky and slightly plastic; common very fine, fine and medium and few coarse roots; many very fine irregular pores; trace pebbles, cobbles and stones; moderately acid (pH 6.0); abrupt smooth boundary. (1 to 7 inches thick)
A2--3 to 11 inches; brown (10YR 5/3) ashy silt loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure parting to weak very fine granular; slightly hard, very friable, nonsticky and slightly plastic; common very fine and fine and few medium and coarse roots; many very fine irregular pores; trace pebbles, cobbles and stones; strongly acid (pH 5.5); clear smooth boundary. (6 to 20 inches thick)
B/E--11 to 29 inches; light yellowish brown (10YR 6/4) and very pale brown (10YR 7/3) ashy silt loam, dark yellowish brown (10YR 4/4) and brown (10YR 5/3) moist; 70 percent B material and 30 percent E material; moderate coarse subangular blocky structure; slightly hard, very friable, nonsticky and slightly plastic; few very fine and fine roots; many very fine tubular pores; 5 percent pebbles and trace cobbles and stones; moderately acid (pH 5.7); clear wavy boundary. (12 to 30 inches thick)
Bt1--29 to 44 inches; pale brown (10YR 6/3) gravelly silt loam, brown (10YR 4/3) moist; strong coarse subangular blocky structure; hard, firm, nonsticky and slightly plastic; few very fine roots; common very fine tubular pores; common distinct clay films on faces of peds and lining pores; many distinct uncoated silt grains on faces of peds; 15 percent pebbles, trace of cobbles and trace of stones; moderately acid (pH 5.8). (10 to 20 inches thick)
Bt2--44 to 60 inches; pale brown (10YR 6/3) very cobbly silt loam, brown (10YR 4/3) moist; strong coarse subangular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine roots; common very fine tubular pores; common distinct clay films on faces of peds and lining pores; many distinct uncoated silt grains on faces of peds; 10 percent pebbles, 20 percent cobbles, 15 percent stones; moderately acid (pH 5.8).
TYPE LOCATION: Fremont County, Idaho; about 34 miles north of Ashton, Idaho; about 2,600 feet west and 800 feet south of the northeast corner of section 19, T. 14 N., R, 45 E.; Latitude - 44 degrees, 31 minutes, 43 seconds North; Longitude - 111 degrees, 11 minutes, 3 seconds West.
RANGE IN CHARACTERISTICS:
Umbric epipedon thickness - 10 to 25 inches
Depth of solum - 40 to greater than 60 inches
Rock fragments in the particle-size control section, weighted average - 5 to 35 percent
Reaction - strongly or moderately acid
Mean annual soil temperature - 33 to 38 degrees F.
Mean summer soil temperature - 39 to 44 degrees F.
Moisture control section - between 4 and 12 inches; dry in all parts of the soil moisture control section for less than 30 consecutive days during the four months following the summer solstice
O horizon Form - commonly forest litter of needles, twigs and leaves on lightly or undisturbed pedons. On pedons where recent, heavy mechanical disturbance has occurred a root mat of elk sedge is common.
A horizons
Value - 4 or 5 dry, 2 or 3 moist
Chroma - 2 or 3 dry or moist
Volcanic glass in the 0.02 to 2.0 mm fraction - 5 to 20 percent
Bulk density - 1.25 to 1.65 grams per cubic centimeter
Acid oxalate extractable Al plus 1/2 Fe - 0.4 to 1.5 percent
Phosphate retention - 40 to 70 percent
15-bar water (air dried samples) - 5 to 12 percent
Base saturation by ammonium acetate - 10 to 30 percent
B/E horizon
Value, B portion - 5 or 6 dry, 4 or 5 moist
E portion - 6 or 7 dry, 5 or 6 moist
Chroma, B portion - 3 or 4 dry or moist
E portion - 2 or 3 dry or moist
Texture of the less than 2 mm fraction - loam, silt loam
Rock fragment content - 5 to 35 percent
Pebbles - 5 to 30 percent
Cobbles - 0 to 15 percent
Stones or boulders - 0 to 15 percent
Volcanic glass in the 0.02 to 2.0 mm fraction - 5 to 20 percent
Bulk density - 1.50 to 1.70 grams per cubic centimeter
Acid oxalate extractable Al plus 1/2 Fe - 0.4 to 1.5 percent
Phosphate retention - 35 to 70 percent
15-bar water (air dried samples) - 5 to 12 percent
Base saturation by ammonium acetate - 30 to 60 percent
Other - 50 to 85 percent B material and 15 to 50 percent E material
Bt horizons
Value - 5 or 6 dry, 4 or 5 moist
Chroma - 3 or 4 dry or moist
Texture of the less than 2 mm fraction - loam, silt loam
Rock fragment content - 5 to 65 percent
Pebbles - 5 to 30 percent
Cobbles - 0 to 20 percent
Stones or boulders - 0 to 15 percent
Volcanic glass in the 0.02 to 2.0 mm fraction - 5 to 20 percent
Bulk density - 1.50 to 1.70 grams per cubic centimeter
Acid oxalate extractable Al plus 1/2 Fe - less than 0.4 percent
Phosphate retention - 35 to 70 percent
Base saturation by ammonium acetate - 50 to 80 percent
Other- a BC horizon is present in some pedons.
COMPETING SERIES: These are the Culdecole, Hopburn, and Vitroff series. Culdecole soils are deep to a lithic contact and do not have an umbric epipedon. Hopburn soils do not have an umbric epipedon. Vitroff soils have an ustic moisture regime, have horizons containing lamellae and do not have an umbric epipedon.
GEOGRAPHIC SETTING: The Oleo soils are on volcanic plateaus. Slopes range from 2 to 15 percent. The soil formed in local alluvium derived from tephra and loess. Elevations range from 6,800 to 8,200 feet. The mean annual precipitation ranges from 30 to 60 inches. Mean annual air temperature is 30 to 36 degrees F. Frost-free season is 0 to 30 days. Frost may occur at anytime throughout the year.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lasac and Dashiki series. Lasac soils occur on knolls intermixed with the Oleo soils and on adjacent plateau escarpments. They are less than 20 inches deep over substratum layers of tephra. Dashiki soils occur on adjacent plateaus. They have ochric epipedons and are moderately deep over substratum layers of tephra.
DRAINAGE AND PERMEABILITY: Well drained; slow to moderate runoff; moderately rapid permeability.
USE AND VEGETATION: Oleo soils are used for recreation, woodland and wildlife habitat. These soils commonly support a lodgepole pine/grouse whortleberry community type. Recent clearcut areas of these soils support communities dominated by elk sedge. The potential native vegetation is a subalpine fir/grouse whortleberry plant association, grouse whortleberry phase.
DISTRIBUTION AND EXTENT: Southeastern Idaho and northwestern Wyoming. The soil is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Targhee National Forest, Fremont County, Idaho, 1997.
REMARKS: Classification changed from Humic to Alfic Vitricryands in 3/95.
Classification changed to Fine-loamy, mixed, superactive Vitrandic Haplocryalfs in 3/04 based on lab data.
Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon - the zone from 1 to 11 inches (A1 and A2 horizons).
Argillic horizon - the zone from 29 to 60 inches (Bt1 and Bt2 horizons).
Particle size-control section - the zone from 29 to 49 inches (Bt1 and part of the Bt2 horizons).
ADDITIONAL DATA: The B/E horizon was sampled and submitted to the National Soil Survey Laboratory, Lincoln, NE for analysis of andic soil properties. Soil survey reference sample number S92ID-043-123, NSSL sample number 93P 313. Full characterization data (8/26/96), NSSL, Lincoln ,NE. Client assigned lab number: S94ID-043-006; project file number: 95P-27; Lab assigned number: pedon 95P 153; samples: 95P 1045-1049.