LOCATION BURNCHEA                NV

Tentative Series
Rev. JWH/JBF
06/2016

BURNCHEA SERIES

The Burnchea series consists of shallow, well drained soils that formed in alluvium derived from mixed rocks and colluvium derived from mixed volcanic rocks. The Burnchea soils are on fan piedmont remnants and intermountain fan remnants. Slopes are 2 to 15 percent. The mean annual precipitation is about 300 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Loamy, mixed, superactive, frigid, shallow Argidic Durixerolls

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

A1--0 to 8 cm; grayish brown (10YR 5/2) very gravelly sandy loam, very dark grayish brown (10YR 3/2), moist; weak thin platy structure; very friable, soft, slightly sticky and slightly plastic; many very fine and fine roots; many fine interstitial pores; 5 percent cobbles and 35 percent gravel; moderately alkaline (pH 8.4); clear smooth boundary.

A2--8 to 28 cm; brown (10YR 5/3) gravelly sandy loam, dark brown (10YR 3/3), moist; moderate medium subangular blocky structure; very friable, soft, slightly sticky and slightly plastic; many very fine to medium roots; common fine tubular pores; 20 percent gravel; moderately alkaline (pH 8.2); clear smooth boundary. (combined thickness of A horizons is 10 to 33 cm)

Bt--28 to 41 cm; yellowish brown (10YR 5/4)gravelly loam, dark yellowish brown (10YR 4/4), moist; strong fine and medium subangular blocky structure; friable, slightly hard, slightly sticky and slightly plastic; many very fine to coarse roots; common fine tubular pores; 5 percent cobbles and 25 percent gravel; moderately alkaline (pH 8.0); abrupt wavy boundary. (12 to 40 cm thick)

Bqm--41 to 81 centimeters; rigid, very hard; continuous strong cementation; clear wavy boundary. (30 to 70 cm thick)

C--81 to 152 centimeters; pale brown (10YR 6/3) very gravelly sandy loam, brown (10YR 4/3), moist; massive; very friable, soft, slightly sticky and slightly plastic; common fine interstitial pores; few faint clay films on ped faces and on surfaces along pores;5 percent stones and 10 percent cobbles and 40 percent gravel; moderately alkaline (pH 8.0)

TYPE LOCATION: Nye County, Nevada; on Elkhorn Canyon Road, about 1,850 feet east and 1,400 feet south of the northwest corner of section 12, T. 8 N., R. 47 1/2 E.; USGS Elkhorn Canyon 7.5 minute topographic quadrangle; latitude 38 degrees 34 minutes 17 seconds N and longitude 116 degrees 37 minutes 43 seconds W; WGS84 Decimal Degrees 38.5713889 latitude, -116.6286111 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry; moist winter and spring, and intermittently moist for 10 to 20 days cumulative between July and September due to convection storms; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 6 to 8 degrees C.
Mollic epipedon thickness: 25 to 38 cm which commonly includes the upper part of the argillic horizon.
Depth to continuous strong cementation: 38 to 50 cm.
Reaction: Slightly alkaline or moderately alkaline.
Other features: Lenses of discontinuous ash are present in some pedons.

Particle-size control Section - Clay content: Averages 25 to 35 percent.
Rock fragment: 5 to 35 percent, mainly gravel.

A horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3.


Bt horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 through 4.
Texture: Clay loam, loam or sandy clay loam.
Clay content: 25 to 35 percent.
Rock fragments: 5 to 35 percent, mainly gravel.
Structure: Subangular or angular blocky or prismatic.

Bqm horizon
Continuous strong cementation and some pedons also have discontinuous indurated lamella.

2C or 2Ck horizons
Value: 4 or 5 moist.
Texture: Sandy loam or loamy sand.
Clay content: 2 to 8 percent.
Rock fragments: 50 to 75 percent, mainly gravel.
Silica cementation: Up to 80 percent weak discontinuous cementation.
Secondary carbonates: None to many carbonate coats on rock fragments.
Effervescence: Noneffervescent to slightly effervescent.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Burnchea soils are on fan piedmont remnants, and mountain valley fans. These soils formed in alluvium derived from mixed volcanic rocks. Slopes are 2 to 15 percent. Elevations are 2,000 to 2,200 meters. The climate is cool and semiarid with moist winters and dry summers. The mean annual precipitation is 250 to 360 mm, average annual temperature is 6 to 8 degrees C, and the frost-free season is about 90 to 110 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lien, Sevenmile and Zadvar soils. Lien soils have indurated duripans. Sevenmile soils are very deep. Zadvar soils have an ochric epipedon and are violently effervescent in the duripan.

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

USE AND VEGETATION: Rangeland and wildlife habitat. The vegetation is principally Mountain big sagebrush, antelope bitterbrush, Nevada ephedra, bottlebrush squirreltail, Thurber's needlegrass singleleaf pinyon and Utah juniper.

DISTRIBUTION AND EXTENT: Southcentral Nevada. MLRA 29. These soils are not extensive.

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

SERIES PROPOSED: Toiyabe-Humbouldt National Forest, Central Part, 2014.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to 28 cm (A1 and A2 horizons).
Argillic horizon - The zone from 28 to 41 cm (Bt horizon).
Strongly cemented duripan - The zone from 41 to 81 cm (Bqm horizon).
Aridic feature - An aridic soil moisture regime bordering on xeric.
Particle-size control section - The zone from 28 to 41 cm (Bt horizon).

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National Cooperative Soil Survey
U.S.A.