LOCATION TWEENER NV
Established Series
Rev. TSB/PWB/RLB/JBF
11/2015
TWEENER SERIES
The Tweener series consists of very shallow and shallow, well drained soils that formed in residuum and colluvium derived from welded tuff, rhyolite, chert, shale and conglomerate. The Tweener soils are on hills and mountains. Slopes are 4 to 75 percent. The mean annual precipitation is about 360 mm and the mean annual temperature is about 7 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Lithic Argixerolls
TYPICAL PEDON: Tweener very cobbly sandy loam--rangeland. The surface is covered with 10 percent gravel and 25 percent cobbles. (Colors are for dry soils unless otherwise noted.)
A--0 to 12 cm; dark grayish brown (10YR 4/2) very cobbly sandy loam, very dark brown (10YR 2/2) moist; weak medium and coarse subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine through coarse roots; few very fine tubular pores; 5 percent stones, 20 percent cobbles, and 10 percent gravel; neutral (pH 7.2); clear wavy boundary. (8 to 20 cm thick)
Bt--12 to 20 cm; brown (10YR 4/3) very cobbly clay loam, dark brown (10YR 3/3) moist; weak medium and coarse subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine and fine, few medium roots; common very fine tubular pores; common thin clay films as bridges; common colloidal stains on faces of ped ; 15 percent stones, 30 percent cobbles, and 10 percent gravel; neutral (pH 7.2); abrupt smooth boundary (8 to 15 cm thick)
R--20 cm; hard, fractured welded tuffs.
TYPE LOCATION: Elko County, Nevada. On a west aspect approximately 2 miles north-northeast of St. Johns ranch buildings; in an unsectioned area, about 5,200 feet east and 2,400 feet south of the southeast corner of section 32, T. 38 N., R. 50 E.; USGS Sugarloaf Butte 7.5 minute topographic quadrangle; latitude 41 degrees, 11 minutes, 59.7 seconds N and longitude 116 degrees 20 minutes, 21.3 seconds W; NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture: Moist in winter and spring, dry from late July through October for consecutive 70 to 100 days; xeric soil moisture regime.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 30 cm and includes all the argillic horizon.
Depth to bedrock: 18 to 36 cm.
Particle-size control section - Clay content: 18 to 35 percent.
Rock fragments: 35 to 60 percent; mainly cobbles and stones fragments of tuff and rhyolite.
A horizon
Value: 4 or 5 dry; 2 or 3 moist.
Bt horizon
Value: 4 or 5 dry; 2 or 3 moist.
Chroma: 2 or 3.
Texture: Very cobbly clay loam or very cobbly loam.
Clay content: 25 to 40 percent.
COMPETING SERIES: These are the
Bellenmine,
Celeridge,
Gabica,
Genoa,
Gerdog,
Gidwin,
Grandeposit,
Hawkridge,
Hutchley,
Loope,
Majorsplace,
Mattier,
Melling,
Pernog,
Realmcoy,
Rozara, and
Shalcleav series.
Bellenmine,
Celeridge,
Gabica,
Gidwin, Grandeposite,
Majorsplace,
Realmcoy, and
Tractuff soils are deeper than 36 cm. Gabica soils have moisture control sections that are dry for 45 to 70 consecutive days and are 30 to 50 cm deep to bedrock.
Genoa and
Shalcleav soils average more than 60 percent rock fragments in the particle-size control section.
Gerdog and
Mattier soils have a xeric soil moisture regime that borders on aridic.
Hawkridge soils have a mean annual soil temperature of 6 to 7 degrees C.
Hutchley soils contain fragments of quartz latite mainly of gravel size.
Pernog soils have a mollic epipedon more than 30 cm thick.
Rozara soils contain 14 to 18 percent clay in the particle-size control section.
GEOGRAPHIC SETTING: Tweener soils are on hill and mountain crests and side slopes. These soils formed in residuum and colluvium derived from welded tuffs, rhyolite, chert, shale, and conglomerate. Slopes are 4 to 75 percent. Elevations are 1,650 to 2,320 meters. The climate is cool semiarid with cool, moist winters and warm, dry summer. The mean annual precipitation is 250 to 400 mm; mean annual temperature is 6 to 7 degrees C; and the frost-free season is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Sumine and the competing
Cleavage soils. Sumine soils are 50 to 100 cm deep to bedrock.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderate to very rapid runoff; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly antelope bitterbrush, Idaho fescue, bluebunch wheatgrass and mountain big sagebrush.
DISTRIBUTION AND EXTENT: Northeast Nevada. MLRA 25. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: ELko County, Nevada, Central Part, 1986.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 20 cm (A and Bt horizon).
Argillic horizon - The zone from 13 to 20 cm (Bt horizon).
Lithic contact - The boundary at 20 cm (R layer).
Particle-size control section - The zone from the soil surface to 20 cm (A and Bt horizons).
National Cooperative Soil Survey
U.S.A.