LOCATION OSOLL                   NV+OR

Established Series
Rev. CEJ-GJS-JVC
03/2016

OSOLL SERIES

The Osoll series consists of shallow to a duripan, well drained soils that formed in residuum and colluvium derived from mixed rocks. Osoll soils are on hills. Slopes are 2 to 50 percent. The mean annual precipitation is about 180 mm and the mean annual temperature is about 9 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic, shallow Typic Haplodurids

TYPICAL PEDON: Osoll gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with approximately 30 percent gravel.

A--0 to 13 cm; light gray (10YR 7/2) gravelly loam, brown (10YR 4/3) moist; moderate thick platy structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine vesicular pores; 30 percent gravel; slightly effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (8 to 15 cm thick)

Bqk--13 to 30 cm; very pale brown (10YR 7/3) very gravelly loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, sticky and slightly plastic; common very fine, fine and medium roots; common very fine and fine interstitial pores; 20 percent 5 to 20 mm very weakly to moderately cemented durinodes; 30 percent gravel and 15 percent cobbles; secondary carbonates segregated as few masses on durinodes and bottoms of rock fragments; strongly effervescent; strongly alkaline (pH 8.8); clear wavy boundary. (10 to 23 cm thick)

Bqkm--30 to 89 cm; very pale brown (10YR 7/4) cemented material, yellowish brown (10YR 5/4) moist; strong thick platy structure with massive strata in between; extremely hard, extremely firm; continuous fractured indurated laminae of silica occurs on upper boundary and in bands throughout horizon separated by discontinuous strong and weakly silica-cemented strata with 20 percent 5 to 20 mm silica and carbonate concretions; violently effervescent; strongly alkaline (pH 9.0); abrupt wavy boundary. (30 to 71 cm thick)

R--89 cm; hard rhyolite capped with 1 cm thick silica-cemented laminae.

TYPE LOCATION: Lander County, Nevada; about 52 miles southwest of Battle Mountain; approximately 800 feet north of the southwest corner of section 36, T. 24 N., R. 40 E; USGS Gilbert Creek NW 7.5 minute topographic quadrangle; latitude 39 degrees 54 minutes 17 seconds N and longitude 117 degrees 26 minutes 4 seconds W; WGS84 Decimal Degrees 39.9047222 latitude, -117.4347222 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Intermittently moist in winter and spring, dry late May through November; typic aridic soil moisture regime.
Mean annual soil temperature: 9 to 11 degrees C.
Depth to indurated duripan: 20 to 36 cm.
Depth to bedrock: 50 to 100 cm to a lithic contact.
Other features: Some pedons have a thin Bw horizon above the Bkq horizon.

Particle-size control section - Clay content: 10 to 18 percent.
Rock fragments: Averages 35 to 60 percent, mainly gravel and some cobbles. Lithology of fragments is mixed.

A horizon
Value: 6 or 7 dry, 3 through 5 moist.
Chroma: 2 to 4, dry or moist.
Reaction: Slightly alkaline or moderately alkaline.

Bqk horizon
Value: 6 or 7 dry, 3 through 5 moist.
Chroma: 3 through 6, dry or moist.
Texture: Very gravelly loam, very gravelly fine sandy loam, very cobbly coarse sandy loam, or very gravelly sandy loam.
Durinodes: Up to 30 percent, weak to hard durinodes are common in any subhorizon.
Reaction: Moderately alkaline or strongly alkaline.
Calcium carbonate equivalent: 1 to 5 percent.

COMPETING SERIES: These are the Osobb, Otomo, Pahroc, and Treadwell series.

Osobb soils have lithic contacts at depths of 23 to 40 cm. Otomo, Pahroc, and Treadwell soils do not have bedrock within 150 cm of the soil surface.

GEOGRAPHIC SETTING: Osoll soils are on hills. They formed in residuum and colluvium derived from volcanic rocks and are strongly influenced by loess. Slopes are 2 to 50 percent. Elevations range from 1,300 to 1,890 meters. The climate is arid with cold, moist winters and warm, dry summers. The mean annual precipitation is 125 to 250 mm, the mean annual temperature is 8 to 10 degrees C, and the frost-free period is 80 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Atlow, Colbar, and Old Camp soils. Atlow and Old Camp soils do not have duripans and have lithic contacts within 50 cm. Colbar soils are moderately deep and do not have a duripan overlying bedrock.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high saturated hydraulic conductivity.

USE AND VEGETATION: Osoll soils are used for rangeland and wildlife habitat. The vegetation is mainly shadscale, bud sagebrush, and bottlebrush squirreltail.

DISTRIBUTION AND EXTENT: Northern Nevada and south-central Oregon. These soils are not extensive with about 9,000 acres of the series mapped to date. The series concept and main acreage is in MLRA 24 in Nevada, while other acreage occurs in MLRA 23 in Oregon.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.

SERIES ESTABLISHED: Lander County (South Part), Nevada, 1985.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 18 cm (A and part of the Bqk horizons).
Durinodes - The zone from 13 to 30 cm (Bqk horizon).
Identifiable secondary carbonates - The zone from 13 to 89 cm (Bqk and Bqkm horizons).
Duripan - The zone from 30 to 89 cm (Bqkm horizon).
Lithic contact - The boundary at 89 cm to underlying hard bedrock (R layer).
Particle-size control section - The zone from the soil surface to 30 cm (A and Bqk horizons).

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National Cooperative Soil Survey
U.S.A.