LOCATION LATHROP                 NV

Established Series
Rev. TM/WED/JBF
06/2016

LATHROP SERIES

The Lathrop series consists of very deep, well drained soils that formed in derived alluvium from mixed rocks. Lathrop soils are on alluvial fans and fan piedmonts. Slopes are 0 to 15 percent. The mean annual precipitation is about 150 mm and the mean annual temperature is about 12 degrees C.

TAXONOMIC CLASS: Fine-loamy over sandy or sandy-skeletal, mixed, superactive, mesic Durinodic Haplargids

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

A--0 to 8 cm; light gray (10YR 7/2) gravelly loam, brown (10YR 4/3) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; few coarse roots; many very fine and fine, and common medium vesicular pores; 30 percent gravel; violently effervescent; strongly alkaline (pH 8.6); abrupt wavy boundary. (5 to 20 cm thick)

Bt--8 to 18 cm; brown (10YR 5/3) clay loam, dark yellowish brown (10YR 4/4) moist; many white (10YR 8/1) sand grains coating the tops of the prisms and top 1.8 cm of the prism faces, light brownish gray (10YR 6/2) top 2.5 cm of the ped faces and light yellowish brown (10YR 6/4) ped interior; moderate medium prismatic structure that parts to strong very fine subangular blocky; soft, very friable, moderately sticky and moderately plastic; many very fine, common fine, and few medium roots; common very fine tubular pores, many faint clay films in pores and common faint clay films on faces of peds; 10 percent gravel; moderately alkaline (pH 8.2); abrupt wavy boundary. (10 to 28 cm thick)

Btk--18 to 33 cm; very pale brown (10YR 7/3) gravelly sandy clay loam, brown (10YR 5/3) moist; massive; soft, very friable, slightly sticky and slightly plastic; many very fine and few fine and medium roots; common very fine tubular pores; common clay coated sand grains and few faint clay films in pores; violently effervescent; 15 percent gravel; strongly alkaline (pH 8.8); clear smooth boundary. (5 to 20 cm thick)

2Bqk--33 to 81 cm; light gray (10YR 7/2) extremely gravelly loamy sand, brown (10YR 5/3) moist; few fine prominent black (10YR 2/1) and brownish yellow (10YR 6/6) redox concentrations moist; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; many very fine tubular and interstitial pores; discontinuous weakly cemented laminae that are hard and firm; 45 percent gravel and 30 percent cobbles, with carbonate coatings on underside, many are partially weathered granitic fragments; violently effervescent; very strongly alkaline (pH 9.2); clear smooth boundary. (10 to 50 cm thick)

2Bk--81 to 152 cm; very pale brown (10YR 8/2) extremely cobbly sand, light gray (10YR 7/2) moist; few fine prominent black (10YR 2/1) and brownish yellow (10YR 6/6) redox concentrations moist; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; many very fine and fine interstitial pores; 40 percent gravel, 40 percent cobbles, 10 percent stones with carbonate coatings on the underside, many are partially weathered granitic fragments; moderately alkaline (pH 8.4).

TYPE LOCATION: Nye County, Nevada; approximately 6 miles south/southwest of Round Mountain, Nevada; 1,050 feet east of west 1/4 corner of section 15, T. 9 N., R. 43 E.; USGS Pablo Canyon Ranch 7.5 minute topographic quadrangle; latitude 38 degrees 38 minutes 21 seconds N and longitude 117 degrees 8 minutes 39 seconds W; WGS84 Decimal Degrees 38.6392778 latitude, -117.1441667 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in some part for short periods 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.
Soil temperature: 12 to 15 degrees C.
Depth to 2Bqk horizon: 25 to 70 cm.

Particle-size control section - Clay content: 20 to 30 percent in the upper part and 0 to 5 percent in the lower part.
Rock fragment: 10 to 30 percent in the upper part and 50 to 90 percent in the lower part.

A horizon
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 or 3.
Reaction: Moderately alkaline or strongly alkaline.
Effervescence: Slightly effervescent to violently effervescent.

Bt and Btk horizon
Hue: 10YR or 7.5YR.
Value: 5 through 7 dry; 4 or 5 moist.
Chroma: 2 through 4.
Texture (less than 2 millimeter): Clay loam, sandy clay loam or loam. Thin subhorizons of fine sandy loam are in some pedons
Reaction: Slightly alkaline through strongly alkaline.
Secondary carbonate accumulation: Carbonate is present in thin filaments or masses in some pedons.
Structure: Prismatic, massive or subangular blocky.
Consistence: Soft to slightly hard, slightly sticky to moderately sticky and slightly plastic to moderately plastic.

2Bqk horizon
Value: 6 through 8 dry, 5 through 7 moist.
Chroma: 2 through 4.
Texture: Loamy sand, loamy coarse sand, sand, coarse sand.
Rock fragments: 50 to 90 percent dominantly gravel and 10 to 50 percent cobbles.
Reaction: Moderately alkaline to very strongly alkaline.
Effervescence: Strongly effervescent to violently effervescent.
Consistence: Slightly hard or very hard, dry; friable to very firm moist.
Durinodes: Soils with friable matrix contain 20 to 40 percent durinodes with weak silica and carbonate cementation.

2Bk (when present)
Value: 6 through 8 dry, 5 through 7 moist.
Chroma: 2 through 4.
Texture: Loamy sand, loamy coarse sand, sand or coarse sand.
Rock fragments: 50 to 90 percent dominantly gravel and 10 to 50 percent cobbles.
Reaction: Moderately alkaline or very strongly alkaline.
Secondary carbonate accumulation: Matrix noncalcareous with carbonate coating the undersides of rock fragments.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Lathrop soils are on alluvial fans and alluvial fan piedmonts. These soils formed in alluvium derived from granitic, rhyolitic, and tuffaceous rocks. Elevations are 1,408 to 2,134 meters. Slopes are 0 to 15 percent. The climate is arid. The mean annual precipitation is 125 to 200 mm, mean annual temperature is 10 to 12 degrees C, and the frost-free season is 100 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Quima and Wardenot soils. Quima soils have a sandy loam particle-size control section. Wardenot soils lack an argillic horizon and are sandy-skeletal.

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

USE AND VEGETATION: Rangeland. Vegetation is principally shadscale, bud sagebrush, winterfat, galleta, littleleaf rabbitbrush, globemallow, king desertgrass, ephedra and Indian ricegrass.

DISTRIBUTION AND EXTENT: Valleys in central Nevada. These soils are moderately extensive. 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 8 cm (A horizon)
Argillic horizon - The zone from 8 to 33 cm (Bt and Btk horizons)
Duric layer - The zone from 33 to 81 cm (2Bqk horizon)
Particle-size control section - The zone from 8 to 33 cm (Bt and Btk horizons).

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National Cooperative Soil Survey
U.S.A.