LOCATION TONKIN                  NV

Established Series
Rev. WMA/ELS/JBF
11/2016

TONKIN SERIES

The Tonkin series consists of very deep, well and moderately well drained soils that formed in mixed alluvium derived primarily from shale, quartzite, conglomerate, limestone, and siliceous rocks. Tonkin soils are on alluvial terraces or lake plains. Slopes are 0 to 1 percent. The mean annual soil temperature is about 225 mm and the annual soil temperature is about 6 degrees C.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Durinodic Xeric Haplocalcids

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

A1--0 to 5 cm; grayish brown (10YR 5/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; massive; soft, very friable, slightly sticky and moderately plastic; few fine and very fine roots; many very fine tubular and vesicular pores; slightly effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (3 to 8 cm thick)

A2--5 to 18 cm; light brownish gray (10YR 6/2) loam, brown (10YR 4/3) moist; massive; soft, very friable, slightly sticky and moderately plastic; common medium, few fine, and many very fine roots; many very fine tubular pores; strongly effervescent; strongly alkaline (pH 8.8); clear smooth boundary. (10 to 20 cm thick)

C--18 to 38 cm; light gray (10YR 7/2) loam, brown (10YR 5/3) moist; massive; soft, very friable, slightly sticky and slightly plastic; common medium, few fine, and many very fine roots; many very fine tubular pores; strongly effervescent; strongly alkaline (pH 9.0); abrupt wavy boundary. (15 to 30 cm thick)

Cqk--38 to 81 cm; light gray (10YR 7/2) light sandy clay loam, brown (10YR 5/3) moist; massive; slightly hard, very friable, moderately sticky and moderately plastic; many fine and very fine roots in mats and in noncemented areas; discontinuously weakly silica-cemented in 70 percent of the horizon with pink (5YR 8/3) coats that are light reddish brown (5YR 6/4) moist; cemented part is very hard, firm, brittle; violently effervescent; very strongly alkaline (pH 9.6); abrupt wavy boundary. (25 to 60 cm thick)

Ck--81 to 99 cm; light gray (10YR 7/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine roots concentrated in pockets; many very fine interstitial pores; noneffervescent except strongly effervescent in carbonate concretions and masses 1 to 5mm. in diameter; very strongly alkaline (pH 9.6); abrupt wavy boundary. (O to 50 cm thick)

Cqk'--99 to 152 cm; light gray (10YR 7/2) loamy fine sand, dark grayish brown (10YR 4/2) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; 50 percent slightly hard durinodes; strongly effervescent; very strongly alkaline (pH 9.6).

TYPE LOCATION: Eureka County, Nevada; approximately 800 feet west and 20 feet south of NE corner sec. 9, T.22 N., R.54E.; USGS West of Christina Pea 7.5 minute topographic quadrangle; latitude 39 degrees 48 minutes 31 seconds N and longitude 115 degrees 53 minutes 34 seconds W; WGS84 Decimal Degrees 39.8086111 latitude, -115.8919444 longitude.

RANGE IN CHARACTERISTICS:
Soil Moisture: Usually dry during the summer and autumn, but are moist in the winter and spring; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 6 to 7 degrees C..
Depth to the silica cemented calcic horizon: 30 to 50 cm.
Hue: 10YR or 2.5Y.

Particle-size control section - Clay content: 18 to 25 percent.

A horizons
Value: 5 or 6 dry, 3 or 4 moist
Chroma: 2 or 3. The surface 18 cm has an average value more than 5.5 dry and 3.5 moist.
Structure: Platy or massive.

C horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3.
Texture: Somewhat stratified with sandy loam, fine sandy loam, loam, clay loam or sandy clay loam.
Sodicity (SAR): 13 to 30.

Cqk horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3.
Texture: Stratified sandy loam to clay loam.
Sodicity (SAR): 13 to 30.
Duric feature: Durinodes in a friable matrix and discontinuous weakly cemented areas and pockets that occupy 40 to 75 percent of the volume of some horizon or subhorizon.

Ck horizon
Carbonates: 15 to 30 percent calcium carbonate equivalent and 5 to 15 percent more carbonates than the underlying horizon as disseminated carbonates or segregated concretions or soft masses.
Sodicity (SAR): 13 to 30.

Cqk' horizon
Texture: Loamy fine sand, gravelly sandy loam or sandy loam.
Rock fragments 0 to 25 percent fine gravel.
Carbonates: 5 to 15 percent calcium carbonate equivalent.
Sodicity (SAR): 13 to 45.

COMPETING SERIES: There are no other series in this family.

GEOGRAPHIC SETTING: Tonkin soils are on alluvial terraces or lake plains at elevations of 1,770 to 1,800 meters. Slope are 0 to 1 percent. The soils formed in mixed alluvium derived primarily from shale, quartzite, conglomerate, limestone, and siliceous rocks. The climate is cool semiarid. Mean annual precipitation is 200 to 250 mm. Mean annual temperature is 5 to 6 degrees C. and the frost free season is 80 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Robeh and Nevka soils. Robeh soils have loamy-skeletal particle-size control sections and lack calcic horizons. Nevka soils lack horizons of silica cementation and have redox concentrations above a depth of 100 cm.

DRAINAGE AND PERMEABILITY: Well and moderately well drained; slow runoff; moderate or moderately slow permeability; moderately high saturated hydraulic conductivity. The water table ranges from about 100 to more than 150 cm.

USE AND VEGETATION: Principally livestock grazing although some areas have been cultivated in the past. Principal vegetation is big sagebrush, rabbitbrush, and saltgrass.

DISTRIBUTION AND EXTENT: Central Nevada. Tonkin soils are inextensive. MLRA 28B.

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

SERIES ESTABLISHED: Eureka County (Diamond Valley Area), Nevada, 1971.

REMARKS: Tonkin soils were formerly classified as Calcisols.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the surface to 18 cm (A and A2 horizons).
Calcic horizon - The zone from about 38 to 99 cm (Cqk and Ck horizons).
Duric feature - The zone from about 38 to 81 cm and 99 to 152 cm (Cqk and Cqk' horizons).
Particle-size control section - The zone from 25 to about 100 cm (Cqk, Ck and a portion of the Bk and Bqk' horizons).

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National Cooperative Soil Survey
U.S.A.