LOCATION UANA NV

Established Series
Rev. HJB/ELS/TM/BKP
02/2024

UANA SERIES

Uana soils consist of moderately deep over a duripan, well drained soils that formed on eroded fan remnants. Slopes are 2 to 15 percent. Uana soils formed in alluvium derived from welded tuff and reworked lacustrine sediments. The mean annual precipitation is about 275 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Fine, smectitic, mesic Argiduridic Durixerolls

TYPICAL PEDON: Uana loam - rangeland (Colors are for dry soil unless otherwise noted.)

A1--0 to 5 cm; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine interstitial pores; 12 percent gravel; neutral (pH 7.0); abrupt smooth boundary.

A2--5 to 8 cm; dark grayish brown (10YR 4/2) sandy clay loam, dark brown (10YR 3/3) moist; moderate fine granular structure; soft, very friable, slightly sticky, slightly plastic; few fine roots; many fine interstitial pores; neutral (pH 7.0); abrupt smooth boundary. (Combined thickness of A horizons is 8 to 26 cm thick)

Bt1--8 to 23 cm; dark brown (7.5YR 3/2) clay, very dark gray (10YR 3/1) moist; moderate medium prismatic structure; hard, firm, moderately sticky and very plastic; common fine and medium roots; few fine and medium tubular pores; common faint clay films in pores and on faces of peds; neutral (pH 6.9); abrupt smooth boundary.

Bt2--23 to 30 cm; dark grayish brown (10YR 4/2) clay, dark brown (10YR 3/3) moist; moderate medium prismatic structure; hard, firm, very sticky and very plastic; common fine and medium roots; few fine and medium tubular pores; many distinct clay films in pores and on the faces of peds; neutral (pH 6.9); abrupt wavy boundary. (Combined thickness of Bt horizons is 21 to 38 cm thick)

Btk--30 to 43 cm; pinkish gray (7.5YR 7/2) clay loam, pinkish gray (7.5YR 6/2) moist; weak medium prismatic structure; slightly hard, friable, moderately sticky and moderately plastic; many fine and coarse roots; many fine tubular pores; few faint clay films on the faces of peds; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (10 to 15 cm thick)

Bqk--43 to 69 cm; white (10YR 8/1) clay loam, light brownish gray (10YR 6/2) moist; moderate thick platy structure; hard, firm, slightly sticky and slightly plastic; few fine roots; few very fine tubular pores; few discontinuous weakly cemented silica laminae; violently effervescent; strongly alkaline (pH 8.6); abrupt wavy boundary. (15 to 30 cm thick)

Bqkm--69 to 97 cm; indurated, 1 to 2 mm thick alternating silica and calcium carbonate laminae that forms a cap on the top of the horizon light brownish gray (10YR 6/2), and brown (10YR 4/3) moist, few continuous and discontinuous laminae alternating with non-cemented very pale brown (10YR 8/2) and light brownish gray (10YR 6/2) sandy loam matrix, light gray (10YR 7/2) and dark grayish brown (10YR 4/2) moist; moderately thick platy structure; hard, very hard, brittle cementation and hard, very firm, nonsticky, and nonplastic; few fine roots; common fine interstitial pores; few silica concretions on the bottom of duripan plates; moderately alkaline (pH 8.4); clear smooth boundary. (25 to 38 cm thick)

2Bk--97 to 150 cm; pinkish gray (7.5YR 6/2) sandy loam, brown (7.5YR 4/4) moist; massive; very hard, very firm, slightly brittle, nonsticky and nonplastic; common very fine roots; few very fine tubular pores; many very pale brown (10YR 8/4) 1 to 5 mm soft weathered tuff fragments; few very thin seams of calcium carbonate within the matrix; few, 5 to 10 mm diameter calcium carbonate masses located towards the lower portion of the horizon; slightly alkaline (pH 7.6), abrupt smooth boundary. (46 to 64 cm thick)

2C--150 to 165 cm; pinkish gray (7.5YR 6/2) sandy loam, brown (7.5YR 4/4) moist; massive; hard, very firm, brittle, nonsticky, nonplastic, many very pale brown (10YR 8/4) soft weathered tuff fragments 1 to 8 mm in diameter; slightly alkaline (pH 7.8).

TYPE LOCATION: Lincoln County, Nevada; about 2,800 feet west and 1,340 feet south from the northeast corner of sec. 7, T 3S, R 70E; USGS Dow Mountain 7.5 minute topographic quadrangle; latitude 37 degrees 39 minutes 41 seconds N and longitude 114 degrees 8 minutes 42.9 seconds W; 751815e, 4172080n, WGS84 Decimal Degrees 37.6613889 latitude, -114.1452500 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, but are moist in the winter and spring and for 10 to 20 days cumulative between July and October due to summer convection storms; aridic bordering on xeric soil moisture regime.
Mean annual soil temperature: 8 to 12 degrees C.
Mollic epipedon thickness: 30 to 41 cm.
Argillic horizon thickness: 36 to 50 cm.
Depth to duripan: 50 to 75 cm.
Duripan thickness: 25 to 38 cm.
Calcium carbonate stage development: IV.

Particle-size control section - Clay content: 35 to 45 percent.
Rock fragments: 0 to 15 percent, mainly gravel.

A horizons
Hue: 10YR or 7.5YR
Value: 4 or 5 dry.
Chroma: 2 or 3 dry and moist.
Organic matter: 2 to 4 percent.
Mineralogy: 15 to 25 percent volcanic glass in the parent material and averages 0.05 to 0.09 percent Al plus 1/2Fe, extracted by ammonium oxalate.

Bt horizons
Hue: 7.5YR or 5YR.
Value: 3 through 5 dry.
Chroma: 1 to 3 dry and moist.
Organic matter: 2 to 4 percent.
Clay content: 40 to 50 percent.
Mineralogy: 15 to 25 percent volcanic glass in the parent material and averages 0.05 to 0.09 percent Al plus 1/2Fe, extracted by ammonium oxalate.
Structure: Weak or moderate prismatic structure.
Consistence: Moderately sticky or very sticky.
Clay films: Common or many, thin or thick clay films on the faces of peds, and lining pores.

Btk and Bqk horizons
Organic matter: 2 to 4 percent.
Clay content: 35 to 45 percent.
Mineralogy: 15 to 25 percent volcanic glass in the parent material and averages 0.05 to 0.09 percent Al plus 1/2Fe, extracted by ammonium oxalate.
Consistence: Slightly sticky or moderately sticky, slightly plastic or moderately plastic.
Calcium carbonate equivalent: 20 to 40 percent in the less than 2 mm fraction.
Reaction: moderately alkaline or strongly alkaline.

Bqkm horizon
Cementation: Strongly cemented through indurated. Some pedons contain sub-horizons of weakly and moderately cemented material that inter-finger with platy layers.
Laminations: Individual indurated laminations vary from 1 to 2 mm thick, the total thickness of continuous silica laminae is 1 to 3 cm thick.

2Bk and 2C horizons
Rock fragments: 0 to 15 percent.
Mineralogy: 10 to 20 percent volcanic glass in the parent material and averages 0.01 to 0.05 percent Al plus 1/2Fe, extracted by ammonium oxalate.
Consistence: hard or very hard, slightly brittle or brittle.
Concentrations: 0 to 5 percent calcium carbonate seams within the matrix and 0 to 5 percent calcium carbonate masses concentrated in sub-horizons of some pedons.

COMPETING SERIES: These are the Appledellia, Graven, Hutchinson, and Studhorse series.

Appledellia, Graven and Hutchinson soil are not moist for 10 to 20 days cumulative between July and October due to summer convection storms. Appledellia soils have a thin duripan, less than 5 cm thick. Hutchinson soils average 15 to 35 percent gravel in the particle-size control section. Studhorse soils have a calcic horizon above the duripan and contain rock fragments in the horizon above the duripan that range up to 40 percent.

GEOGRAPHIC SETTING: Uana soils are on eroded fan remnants at elevations of 1,800 to 2,150 meters. Slopes are 2 to 15 percent. Uana soils formed in alluvium from welded tuff and mixed lacustrine sediments. The climate is cool continental, with a mean annual precipitation of 200 to 300 mm and a mean annual temperature between 7 to 11 degrees C. The frost free period is 100 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Acoma, Cedaran, Decan and Wakansapa soils. Acoma soils have an Ochric epipedon and a calcic horizon between below an argillic horizon at 75 and 100 cm. Cedaran and Wakansapa soils are shallow to bedrock. Decan soils have a Mollic epipedon that averages 18 to 30 cm.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; slow or medium runoff; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: Used for livestock grazing and wildlife habitat. Potential native vegetation is black sagebrush, antelope bitterbrush, and Indian ricegrass. This pedon is correlated to ecological site Shallow Clay Loam 8-12 P.Z., R029XY104NV.

DISTRIBUTION AND EXTENT: East-central Nevada. Uana soils are of small extent. MLRA 28A and 29.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: DAVIS, CALIFORNIA

SERIES ESTABLISHED: Lincoln County (Meadow Valley Area), Nevada, 1971.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 30 cm (A1, A2, Bt1, and Bt2 horizons).
Argillic horizon - The zone from 8 to 43 cm (Bt1, Bt2, and Btk horizons).
Duripan - The zone from 69 to 97 cm (Bqkm horizon).
Particle-size control section - The zone from 8 to 43 cm (Bt1, Bt2, and Btk horizons).

These soils were formerly classified as Chestnut soils.

National Cooperative Soil Survey
U.S.A.