LOCATION OLATON IDEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Pachic Ultic Haploxerolls
TYPICAL PEDON: Olaton fine gravelly coarse sandy loam -- on a concave north-facing slope of 74 percent at 4,760 feet elevation in rangeland. When described on July 11, 1995, the soil was dry to 24 inches and slightly moist below. (Colors are for air-dry soil unless otherwise noted.)
A--0 to 5 inches; very dark grayish brown (10YR 3/2) fine gravelly coarse sandy loam, black (10YR 2/1) moist; weak fine granular structure; soft, very friable, nonsticky and slightly plastic; many very fine and fine, few medium and coarse roots; many very fine, fine and medium irregular pores; 15 percent fine gravel; moderately acid (pH 6.0); clear smooth boundary. (3 to 15 inches thick)
AB--5 to 22 inches; very dark grayish brown (10YR 3/2) fine gravelly coarse sandy loam, black (10YR 2/1) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; many very fine and fine, few medium and coarse roots; many very fine and fine tubular and irregular pores; 15 percent fine gravel; moderately acid (pH 5.9); abrupt wavy boundary. (10 to 25 inches thick)
Bw1--22 to 38 inches; brown (10YR 5/3) fine gravelly coarse sandy loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; many very fine and fine, few medium and coarse roots; many very fine and fine tubular and irregular pores; 15 percent fine gravel, 5 percent stones; moderately acid (pH 5.9); abrupt wavy boundary. (10 to 30 inches thick)
Bw2--38 to 55 inches; brown (10YR 5/3) fine gravelly loamy coarse sand, brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, few medium and coarse roots; many very fine and fine tubular and irregular pores; 30 percent fine gravel; moderately acid (pH 5.9); abrupt wavy boundary. (12 to 30 inches thick)
C--55 to 65 inches; pale brown (10YR 6/3) very gravelly loamy coarse sand, brown (10YR 5/3) moist; single grain; loose, nonsticky and nonplastic; few very fine roots; common very fine irregular pores; 35 percent fine gravel, 10 percent cobbles; moderately acid (pH 6.0).
TYPE LOCATION: Boise County, Idaho; about 4 miles northeast of Boise; 2,600 feet north and 1,150 feet west of the southeast corner of section 36, T.5 N., R.2 E.; USGS Boise North Quadrangle; Latitude - 43 degrees, 43 minutes, 36 seconds N. and Longitude - 116 degrees, 09 minutes, 28 seconds W.; NAD 83.
RANGE IN CHARACTERISTICS:
Mollic epipedon thickness - 20 to 55 inches
Depth to bedrock - greater than 60 inches
Base saturation - 50 to 75 percent in the zone from 10 to 30 inches
Reaction - moderately acid or slightly acid
Particle-size control section - 5 to 10 percent clay; 5 to 35 percent rock fragments
Moisture control section - dry 60 to 90 consecutive days following the summer solstice
Average annual soil temperature - 47 to 53 degrees F.
A and AB horizons
Value - 3 or 4 dry
Chroma - 1 or 2 dry or moist
Rock fragments - 5 to 35 percent gravel
Bw horizon
Value - 4 or 5 dry, 3 or 4 moist
Chroma - 2 or 3 dry or moist
Texture - SL or COSL
Clay content - 5 to 15 percent
Rock fragments - 0 to 5 percent stones, 0 to 5 percent cobbles, 5 to 35 percent gravel and 5 to 35 percent total
C horizon
Value - 5 or 6 dry, 4 or 5 moist
Chroma - 2 or 3 dry or moist
Texture - SL, COSL or LCOS
Clay content - 4 to 15 percent
Rock fragments - 0 to 5 percent stones, 0 to 15 percent cobbles, 15 to 45 percent gravel and 15 to 60 percent total
COMPETING SERIES: These are the Ben Lomond, Drybuck and Junipero series. Ben Lomond and Drybuck soils have O horizons and are 40 to 60 inches to a paralithic contact. Junipero soils have O horizons and are 20 to 40 inches to a paralithic contact.
GEOGRAPHIC SETTING: Olaton soils are on hill backslopes and footslopes, and canyon walls at elevations of 2,650 to 6,400 feet, occurring only on south aspects at higher elevations. These soils formed in colluvium and alluvium from granitic rocks. Slopes range from 4 to 90 percent. The average annual precipitation is 13 to 22 inches. The average annual temperature is 45 to 51 degrees F. The frost-free period is 90 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dobson, Kisky, Roney, Schiller and Shimo soils. Dobson and Kisky are shallow to bedrock on summits and convex geomorphic positions. Roney and Shimo soils are moderately deep to bedrock on similar geomorphic positions. Schiller soils are loamy-skeletal on similar geomorphic positions.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow to very rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Olaton soils are used mainly for rangeland and wildlife habitat. Native vegetation is xeric big sagebrush, antelope bitterbrush, bluebunch wheatgrass, Idaho fescue, and in places bitter cherry and chokecherry.
DISTRIBUTION AND EXTENT: West-central Idaho. MLRA 10. Olaton soils are of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Boise County Area, Idaho, Parts of Ada and Boise Counties, 2005.
REMARKS: Diagnostic horizons and features recognized in this soil:
Mollic epipedon - zone from the soil surface to 38 inches (A, AB and Bw1 horizons)
Cambic horizon - zone from 38 to 55 inches (Bw2 horizon)
Particle-size control section - zone from 10 to 40 inches
Soil moisture regime - xeric
ADDITIONAL DATA: Characterization sample no. S95-015-003 (NSSL pedon 95P929)