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 pebbles and 10 percent cobbles. (Colors are for dry soil unless otherwise noted).
A--0 to 3 inches; 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 to fine roots; many very fine, and fine, few medium vesicular pores; 35 percent pebbles; noneffervescent; mildly alkaline (pH 7.6); clear smooth boundary. (1 to 4 inches thick)
Bt--3 to 8 inches; brown (10YR 5/3) gravelly silt loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine to fine roots; common very fine tubular pores; few thin clay films coating ped faces; 15 percent pebbles; noneffervescent matrix; mildly alkaline (pH 7.8); clear smooth boundary. (0 to 6 inches thick)
Btq--8 to 12 inches; brown (10YR 5/3) very gravelly silt loam, dark brown (10YR 3/3) moist; weak fine angular blocky structure parting to moderate medium subangular blocky; slightly hard, friable, sticky and plastic; common very fine through fine roots; moderate 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 pebbles, 15 percent cobbles; noneffervescent matrix; moderately alkaline (pH 8.0); clear wavy boundary. (4 to 10 inches thick)
2Btqk--12 to 15 inches; brown (10YR 5/3) extremely cobbly loam, brown to dark brown (10YR 4/3) moist; weak fine subangular blocky structure; slightly hard, very friable, sticky and plastic; moderate very fine and fine roots; moderate very fine tubular pores; few thin clay films coating ped faces; 3 to 10 millimeter thick lime and silica pendants on undersides of rock fragments; 40 percent pebbles, 35 percent cobbles; violently effervescent; mildly alkaline (pH 7.8); abrupt wavy boundary. (3 to 6 inches thick)
2R--15 inches; 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.; 39 degrees, 24 minutes, 38 seconds north latitude and 115 degrees, 8 minutes, 0 seconds west longitude.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually dry, moist in winter and spring, dry summer and fall. (Aridic)
Soil temperature - 47 to 52 degrees F.
Depth to bedrock - 14 to 20 inches.
Mollic epipedon thickness - 8 to 16 inches, includes the upper part of the argillic horizon.
Reaction - Mildly alkaline to moderately alkaline.
Control section - Clay content: 27 to 35 percent.
Rock fragments: 35 to 60 percent, of which 20 to 50 percent are pebbles 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(T WA), Bellehelen(NV), Brier(NV), Chinabutte (T ID), Clovercreek(WA), Duco(NV), Gwin(WA), Horseflat(WA), Orhood(CA), Reywat(ID) and Windry(T WA) 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 soils are also 7 to 14 inches to rock. Brier and Duco soils also lack silty and cobbly textures in the particle size control section. Chinabutte and Gwin soils also have Xeric moisture regimes, and reaction is neutral to slightly acid. Clovercreek soils also have Xeric moisture regimes, have AB horizons and lack cobbly textures in the particle size control section. Orhood soils also have neutral reactions and have 7.5YR hues in the particle size control section. Reywat soils also have Xeric moisture regimes, and have Bt horizons dominated by basalt rock fragments.
GEOGRAPHIC SETTING: Upatad soils are on hills and mountains. These soils formed in residuum and colluvium from rhyolite, andesite and welded tuffs. Slopes are 8 to 50 percent. Elevations are 5200 to 7800 feet. The climate is cool, semi-arid with cool, moist winters and warm, dry summers. The mean annual precipitation is 12 to 16 inches; mean annual temperature is 44 to 49 degrees F.; 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. MLRA 28B.
USE AND VEGETATION: Rangeland, 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 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 12 inches (A, Bt1 and Bt2 horizons).
Argillic horizon - The zone from 3 to 15 inches (Bt, Bt2 and 2Btqk horizons).
Lithic contact - The contact with hard rock at about 15 inches.
Particle-size control section - The zone from 3 inches to about 15 inches (Bt1, Bt2 and 2Btk3 horizons).