LOCATION ORPHANT                 NV

Established Series
Rev: GAR/WED/JBF
06/2016

ORPHANT SERIES

The Orphant series consists of shallow, well drained soils that formed in mixed alluvium derived from dominantly volcanic rocks. Orphant soils are on fan piedmonts and fan skirts. Slopes are 0 to 8 percent. The mean annual precipitation is about 150 mm and the mean annual temperature is about 12 degrees C.

TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Argidic Argidurids

TYPICAL PEDON: Orphant very gravelly fine sand--rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 3 cm; light brownish gray (10YR 6/2) very gravelly fine sand, dark grayish brown (10YR 4/2) moist; single grained; loose, nonsticky and nonplastic; 35 percent gravel; few very fine and fine roots; many very fine interstitial pores; neutral (pH 6.8); clear smooth boundary. (3 to 15 cm thick)

E--3 to 10 cm; light gray (10YR 7/1) fine sandy loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common very fine and few fine and medium roots; many very fine and fine, and common medium and coarse vesicular pores; slightly alkaline (pH 7.4); abrupt smooth boundary. (5 to 13 cm thick)

Bt--10 to 20 cm; yellowish brown (10YR 5/4) loam, many bleached light gray (10YR 7/2) sand grains, in upper 2.5 to 3.8 cm, dark yellowish brown (10YR 4/4) moist; weak coarse prismatic structure parting to moderate thin and medium platy; slightly hard, friable, slightly sticky and slightly plastic; many very fine, common fine, and few medium roots; many very fine interstitial and common very fine and fine tubular pores, common faint clay films on faces of peds and many faint clay films in pores; moderately alkaline (pH 8.4); clear wavy boundary. (5 to 20 cm thick)

Btqk--20 to 38 cm; pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; massive; hard and very hard, firm and very firm, slightly sticky, slightly plastic; common very fine and fine roots; few very fine tubular and common very fine interstitial pores; common faint dark yellowish brown (10YR 4/4) clay films bridging sand grains; many medium and coarse prominent white (10YR 8/1) carbonate seams and few weakly cemented discontinuous very thin silica laminae and common thin silica bridging; noncalcareous matrix and violently effervescent in seams; very strongly alkaline (pH 9.2); clear wavy boundary. (5 to 20 cm thick)

Bqkm--38 to 56 cm; strong brown (7.5YR 5/6) strongly cemented duripan consisting of many thin (3 mm. thick) very pale brown (10YR 7/4) and white (10YR 8/1) continuous laminae mostly horizontal but some vertical and diagonal with weakly cemented material between the laminae; brown (7.5YR 4/4) moist; moderate thin and medium platy structure; very hard and extremely hard, very firm and extremely firm; few very fine roots and some root mats on laminae; common very fine interstitial pores; strongly effervescent but violently effervescent in seams; very strongly alkaline (pH 9.6); clear wavy boundary. (10 to 28 cm thick)

2Bqk--56 to 99 cm; light yellowish brown (10YR 6/4) loamy sand, dark yellowish brown (10YR 4/4) moist; massive; hard and very hard, firm and very firm; few very fine roots; many very fine interstitial, and common very fine and fine tubular pores; many medium and fine, and few coarse and very coarse white (10YR 8/1) carbonate in soft masses and common thin discontinuous silica laminae and bridging in pockets; strongly and violently effervescent; strongly alkaline (pH 8.6); gradual wavy boundary. (20 to 50 cm thick)

2Bqkm--99 to 140 cm; pale brown (10YR 6/3) strongly cemented duripan with many very thin continuous silica laminae and very thin silica bridging, dark brown (10YR 3/3) moist; massive; extremely hard, very firm; common very fine interstitial pores; slightly effervescent and violently effervescent; moderately alkaline (pH 8.4).

TYPE LOCATION: Nye County, Nevada; about 4.5 miles southeast of the San Antonio Ranch; 0.3 mile south of the northwest corner of Section 2, T. 6 N., R. 42 E.; USGS Baxter Spring NW 7.5 minute topographic quadrangle; latitude 38 degrees 24 minutes 32 seconds N and longitude 117 degrees 14 minutes 28 seconds W; WGS84 Decimal Degrees 38.4090000 latitude, -117.2413889 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in some part for short periods during winter and early spring months and for 10 to 20 days cumulative between July and October due to convection storms; typic aridic soil moisture regime.
Mean annual soil temperature: 12 to 15 degrees C.
Depth to duripans: 36 to 50 cm and 89 to 100 cm.
Carbonates: Noneffervescent through violently effervescent.

Particle-size control section - Percent clay: 18 to 25 percent.
Rock fragments: Averages 0 to 20 percent.

A horizon
Value: 6 or 7 dry, 3 or 4 moist.
Chroma: 2 or 3.
Reaction: Neutral or slightly alkaline.

E horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 1 through 3.
Structure: Massive or subangular blocky.
Reaction: Neutral or slightly alkaline.

Bt & Btqk horizons
Value: 5 through 7 dry, 4 through 6 moist.
Chroma: 2 through 4.
Texture: Fine sandy loam, loam or sandy clay loam.
Clay percent: 18 to 25 percent.
Rock fragments: 0 to 30 percent, cobbles and gravel.
Structure: Prismatic structure, platy or subangular blocky.
Reaction: Slightly alkaline through very strongly alkaline.

Bqkm horizon
Features: More than one duripan is present in most pedons.
Structure: Platy or massive.
Reaction: Slightly alkaline through very strongly alkaline.

2Bqk horizon
Hue: 10YR or 7.5YR.
Value: 5 through 8 dry, 3 through 6 moist.
Chroma: 2 through 4.
Structure: Massive or single grained.

COMPETING SERIES: These are the Belted, Deppy, Dobel, and Vylach series.

Belted soils have a duripan at 15 to 36 cm. Deppy soils have a mean annual soil temperature of 8 to 9.5 degrees C> Dobel soils have an indurated duripan within 50 to 100 cm. Vylach soils have bedrock at a depth of 50 to 75 cm.

GEOGRAPHIC SETTING: Orphant soils are on fan piedmonts and fan skirts at elevations of 1,680 to 1,890 meters. Slopes are 0 to 8 percent. These soils formed in mixed alluvium derived from dominantly volcanic rocks. The mean annual precipitation is 100 to 200 mm, mean annual temperature is about 11 to 13 degrees C, and the frost-free season is 100 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Broe, Pintwater and Roic soils. Broe soils have a sandy particle-size control section and durinodes in a friable matrix. Pintwater soils have a lithic contact within a depth of 50 cm. Roic soils have a paralithic contact within a depth of 50 cm.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium runoff; moderately high saturated hydraulic conductivity above the duripan.

USE AND VEGETATION: Livestock grazing and wildlife habitat. The vegetation is principally shadscale, bud sagebrush and galleta with some littleleaf horsebrush and kochia.

DISTRIBUTION AND EXTENT: South-central Nevada. These soils are inextensive. MLRA 29

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

SERIES ESTABLISHED: Nye County (Big Smoky Valley Area), Nevada, 1972.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 10 cm (A and E horizons).
Argillic horizon - The zone from 10 to 38 cm (Bt and Btqk horizon).
Strongly cemented hardpan - The zone from 38 to 56 cm (Bqkm horizon).
Particle-size control section - The zone from 10 to 38 cm (Bt and Btqk horizons).

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National Cooperative Soil Survey
U.S.A.