LOCATION UPATAD NVEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Lithic Argixerolls
TYPICAL PEDON: Upatad very gravelly silt loam, rangeland. The soil surface is partially covered with approximately 40 percent gravel and 10 percent cobbles. (Colors are for dry soil unless otherwise noted).
A--0 to 8 cm; grayish brown (10YR 5/2) very gravelly silt loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine, and fine, few medium vesicular pores; 35 percent gravel; noneffervescent; slightly alkaline (pH 7.6); clear smooth boundary. (3 to 10 cm thick)
Bt--8 to 20 cm; brown (10YR 5/3) gravelly silt loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine tubular pores; few thin clay films coating ped faces; 15 percent gravel; noneffervescent matrix; slightly alkaline (pH 7.8); clear smooth boundary. (0 to 15 cm thick)
Btq--20 to 30 cm; brown (10YR 5/3) very gravelly silt loam, dark brown (10YR 3/3) moist; weak fine angular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine tubular pores; few thin clay films coating ped faces and pores; 10 percent hard and firm discontinuous silica cementation; 10 percent fine silica concretion; durinodes; few thin lime coats and pendants on undersides of rock fragments; 25 percent gravel and 15 percent cobbles; noneffervescent matrix; moderately alkaline (pH 8.0); clear wavy boundary. (10 to 25 cm thick)
2Btqk--30 to 38 cm; brown (10YR 5/3) extremely cobbly loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine tubular pores; few thin clay films coating ped faces; 3 to 10 mm thick lime and silica pendants on undersides of rock fragments; 40 percent gravel and 35 percent cobbles; violently effervescent; slightly alkaline (pH 7.8); abrupt wavy boundary. (8 to 15 cm thick)
2R--38 cm; hard nonfractured andesite.
TYPE LOCATION: White Pine County, Nevada; approximately 3 miles west of Robinson Summit, about 1300 feet north and 2500 feet east of the southwest corner of section 20, T. 18 N., R. 61 E.; latitude 39 degrees 24 minutes 38 seconds N and longitude 115 degrees 8 minutes 4 seconds W; NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in winter and spring, dry summer and fall; typic aridic soil moisture regime.
Mean annual soil temperature: 8 to 11 degrees C.
Depth to bedrock: 36 to 50 cm.
Mollic epipedon thickness: 20 to 40 cm, includes the upper part of the argillic horizon.
Reaction: Slightly alkaline to moderately alkaline.
Particle-size control section - Clay content: 27 to 35 percent.
Rock fragments: 35 to 60 percent, of which 20 to 50 percent are gravel and 10 to 40 percent are cobbles.
A horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3.
Bt and Btq horizons
Structure: Weak to moderate, fine to medium angular or subangular blocky.
Concretions: 5 to 15 percent fine to coarse, irregular silica concretions.
2Btqk horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 through 4.
Structure: Weak to moderate, fine to medium subangular blocky.
Other features: Many thin to thick lime and silica pendants on undersides of rock fragments. Few to common, fine to medium, soft masses of lime on undersides of rock fragments.
COMPETING SERIES: These are the Argabak, Bellehelen, Brier, Canfire, Chinabutte, Clovercreek, Duco, Gwin, Horseflat, Nuhelen, Ocud, Orhood, Reywat, Shepridge, and Windry series.
All of these soils lack Bk horizons and accumulations of soft, powdery secondary carbonates in the subsoil. Bellehelen and Brier soils also are moist for 10 to 20 consecutive days in July to October due to summer convection storms. Bellehelen, Nuhelen and Ocud soils are also 18 to 36 cm to rock. Brier and Duco soils also lack silty and cobbly textures in the particle-size control section. Canfire, Chinabutte, Clovercreek, Gwin, Reywat and Stepmount soils have a xeric soil moisture regime. Orhood soils also have neutral reactions and have 7.5YR hues in the particle size control section. Shepridge soils have 18 to 27 percent clay. Windry soils have an AB horizon.
GEOGRAPHIC SETTING: Upatad soils are on hills and mountains. These soils formed in residuum and colluvium derived from rhyolite, andesite and welded tuffs. Slopes are 8 to 50 percent. Elevations are 1,590 to 2,380 meters. The climate is cool, semi-arid with cool, moist winters and warm, dry summers. The mean annual precipitation is 300 to 400 mm; mean annual temperature is 7 to 9 degrees C.; and the frost-free season is 100 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Atlow and Pioche series. Atlow soils lack mollic epipedons and Pioche soils have more than 35 percent clay in the particle-size control section.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: Livestock grazing, woodland, and wildlife habitat. The present vegetation is mainly black sagebrush, bluebunch wheatgrass, nevada bluegrass, bottlebrush squirreltail, thurber needlegrass with a minor invasion of pinyon and juniper. The eroded phase of Upatad is pinyon and Juniper woodland with an understory as above.
DISTRIBUTION AND EXTENT: East Central Nevada. These soils are moderately extensive. MLRA 28B.
MLRA OFFICE RESPONSIBLE: Reno, Nevada
SERIES ESTABLISHED: White Pine County, Nevada, West Part, 1990.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to a depth of about 30 cm (A, Bt1 and Bt2 horizons).
Argillic horizon - The zone from 8 to 38 cm (Bt, Bt2 and 2Btqk horizons).
Lithic contact - The contact with hard rock at about 38 cm (2R layer).
Particle-size control section - The zone from 8 cm to about 38 cm (Bt1, Bt2 and 2Btk3 horizons).