LOCATION BOULFLAT                NV

Established Series
Rev. CEJ/RLB/JBF
02/2016

BOULFLAT SERIES

The Boulflat series consists of moderately deep, well drained soils formed in residuum and colluvium derived from chert, shale, quartzite and andesite with a component of loess high in volcanic ash. The Boulflat soils are on mountain and hill crests and side slopes. Slopes are 4 to 30 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Haploxeralfic Argidurids

TYPICAL PEDON: Boulflat gravelly loam--rangeland. (Colors are for dry soils unless otherwise noted.)

A--0 to 10 cm; light brownish gray (10YR 6/2) gravelly loam, brown (10YR 4/3) moist; strong fine thin platy structure; soft, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; few fine interstitial and many very fine vesicular pores; 20 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary. (5 to 15 cm thick)

AB--10 to 20 cm; pale brown (10YR 6/3) gravelly loam, dark yellowish brown (10YR 3/4) moist; moderate very fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine and few medium roots; common very fine tubular and few very fine interstitial pores; 25 percent gravel; neutral (pH 7.2); clear wavy boundary. (0 to 15 cm thick)

Bt--20 to 33 cm; pale brown (10YR 6/3) gravelly clay loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many very fine, common fine, and few medium and coarse roots; common very fine interstitial pores; many prominent clay films in pores, few faint clay films on peds; 20 percent gravel; neutral (pH 7.2); abrupt smooth boundary. (10 to 30 cm thick)

Bk--33 to 58 cm; light gray (10YR 7/2) very gravelly loam, brown (10YR 4/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; many very fine, common fine, and few medium roots; common very fine interstitial pores; 40 percent gravel; strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (20 to 36 cm thick)

Bkqm--58 to 86 cm; light gray (10YR 7/2), white (10YR 8/1) strongly cemented gravelly duripan with many very pale brown discontinuous, unoriented silica laminae, light gray (10YR 7/2), very pale brown (10YR 8/2) and very pale brown (10YR 7/4) moist; massive; extremely hard, very firm; few very fine, fine and medium roots; many very fine interstitial pores; violently effervescent; strongly alkaline (pH 8.6); abrupt wavy boundary. (5 to 38 cm thick)

2R--86 to 104 cm; fractured quartzite and chert.

TYPE LOCATION: Eureka County, Nevada; about 1 1/2 miles northeast of The junction of Highways I-80 and Nevada State 21; approximately 2,900 feet north of the southwest corner of section 2, T. 32 N., R. 49 E., Mount Diablo base line and meridian; USGS Bobs Flat 7.5 minute topographic quadrangle; latitude 40 degrees 40 minutes 31 seconds N and longitude 116 degrees 25 minutes 28 seconds W; WGS84 Decimal Degrees 40.6752778 latitude, -116.4244444 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in some part from late October through early June; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Combined thickness of A and Bt horizons: 20 to 50 cm.
Depth to strongly cemented duripan: 50 to 86 cm.
Depth to hard bedrock: 56 to 100 cm.

Particle-size control section - Clay content: 25 to 35 percent.
Rock fragments: 15 to 35 percent, mainly gravel.

A horizon
Value: 5 through 7 dry, 3 or 4 moist.
Chroma: 2 or 3.
Reaction: Neutral or slightly alkaline.

Bt horizons
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 3 or 4.
Texture: Gravelly loam, gravelly clay loam, or gravelly sandy clay loam.
Structure: Weak or moderate, very fine to medium subangular or angular blocky.
Reaction: Neutral or slightly alkaline.

Bk horizons
Texture: Very gravelly loam or very gravelly sandy loam.
Rock fragments: 35 to 60 percent, mainly gravel.
Reaction: Slightly alkaline or moderately alkaline.
Effervescence: Strongly effervescent or violently effervescent.
Carbonates: All gravel are carbonate coated.

Bkqm horizon
Value: 7 or 8 dry, 6 through 8 moist.
Chroma: 1 through 4.
Effervescence: Strongly effervescent or violently effervescent.
Silica laminae: Up to 5 mm thick and not continuous horizontally.
Other features: Strongly cemented duripan rests directly on bedrock.

COMPETING SERIES: These are Aquinas, Cherry Spring, Eastval, Spasprey, Yody and Zaidy series.

Aquinas, Cherry Spring, Eastval, Spasprey, Yody and Zaidy soils all lack bedrock within a depth of 100 cm. In addition, Aquinas Cherry Spring and Eastvall soils have a combined A and Bt thickness of more than 50 cm and Yody soils have a calcic horizon above the duripan.

GEOGRAPHIC SETTING: Boulflat soils are on mountain and hill crests and side slopes. These soils formed in residuum and colluvium derived from chert, shale, quartzite and andesite with a component of loess high in volcanic ash. Slopes are 4 to 30 percent. Elevations are 1,520 to 1,830 meters. The climate is cool, semiarid with hot dry summers and cool, moist winters. The mean annual precipitation is 200 to 250 mm; mean annual temperature is 7 to 8 degrees C, and the frost-free season is 100 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are The Brock, Havingdon, Humdun and Rad soils. Brock soils have indurated duripans at shallow depths. Havingdon soils have clayey-skeletal particle-size control sections and are moderately deep over bedrock. Humdun soils are very deep and have coarse-loamy particle-size control sections. Rad soils are very deep and have coarse-silty particle-size control sections.

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

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly Wyoming big sagebrush, Douglas rabbitbrush, Thurber needlegrass, Sandberg bluegrass and cheatgrass.

DISTRIBUTION AND EXTENT: North central Nevada. These soils are not extensive. MLRA 24.

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

SERIES ESTABLISHED: Eureka County, (Tuscarora Mountain Area) Nevada, 1979.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 20 cm (A, AB horizons).
Argillic horizon - The zone from 20 to 33 cm (Bt horizon).
Strongly cemented duripan - The zone from 58 to 86 cm (Bkqm horizon).
Lithic contact - The boundary at about 86 cm (R layer).
Particle-size control section - The zone from 20 to 33 cm (Bt and Bk horizons).

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National Cooperative Soil Survey
U.S.A.