LOCATION LEWDLAC                 NV

Established Series
Rev. HJB/RLB/TM
11/2015

LEWDLAC SERIES

The Lewdlac series consists of shallow over a strongly cemented duripan, well drained soils that formed in mixed alluvium dominantly from quartzite over reworked lacustrine sediments. The Lewdlac soils are on relict alluvial flats and have slopes of 0 to 8 percent. The mean annual precipitation is about 4 inches and the mean annual temperature is about 61 degrees F.

TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Cambidic Haplodurids

TYPICAL PEDON: Lewdlac gravelly loamy fine sand, rangeland. (Colors are for dry soil unless otherwise noted.) The surface is covered with a thin mantle of windblown sand over a partial desert pavement of pebbles that covers about 60 percent of the soil surface.

A--0 to 3 inches; pale brown (10YR 6/3) gravelly loamy fine sand, yellowish brown (10YR 5/4) moist; weak coarse platy structure; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine interstitial and few very fine tubular pores; 15 percent pebbles; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (2 to 4 inches thick)

Bk1--3 to 10 inches; very pale brown (10YR 7/3) fine sandy loam, light yellowish brown (10YR 6/4) moist; moderate medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; common very fine interstitial and few very fine tubular pores; 10 percent pebbles; few fine lime filaments; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (5 to 10 inches thick)

Bk2--10 to 16 inches; very pale brown (10YR 7/4) fine sandy loam, yellowish brown (10YR 5/6) moist; weak, medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine, few fine and medium roots; common very fine interstitial pores; 10 percent pebbles; silica and lime pendants on undersides of most pebbles; few fine lime filaments; violently effervescent; strongly alkaline (pH 8.6); abrupt wavy boundary. (4 to 8 inches thick)

Bqkm--16 to 21 inches; very pale brown (10YR 8/2) strongly cemented duripan, very pale brown (10YR 7/4) moist; massive; hard, very firm, brittle; few very fine and fine roots in fractures and between plates; few very fine and fine interstitial pores; few discontinuous laminar silica lenses and caps on plates; 15 percent pebbles; violently effervescent; clear irregular boundary. (5 to 10 inches thick)

2C1--21 to 29 inches; very pale brown (10YR 8/3 and 10YR 7/4) gravelly sandy clay loam, very pale brown (10YR 7/4) and brownish yellow (10YR 6/6) moist; weak coarse prismatic structure parting to medium coarse subangular blocky; very hard, firm, slightly sticky and slightly plastic; few very fine and fine interstitial, with few very fine tubular pores; 15 percent pebbles; strongly effervescent; strongly alkaline (pH 9.0); diffuse irregular boundary. (5 to 11 inches thick)

2C2--29 to 41 inches; very pale brown (10YR 7/4) gravelly clay loam; few fine prominent red (2.5YR 5/6) and reddish yellow (7.5YR 6/6) mottles; weak coarse prismatic structure parting to moderate coarse subangular blocky; very hard, very firm, sticky and plastic; few very fine interstitial and tubular pores; 25 percent pebbles, 5 percent cobbles; strongly effervescent; very strongly alkaline (pH 9.2); diffuse wavy boundary. (9 to 15 inches thick)

2C3--41 to 60 inches; very pale brown (10YR 7/4) extremely gravelly clay loam, light yellowish brown (10YR 6/4) moist; weak medium subangular blocky structure; hard, firm, sticky and plastic; few very fine roots; few very fine interstitial and tubular pores; 50 percent pebbles, 10 percent cobbles; common small pockets of weakly cemented fine sandy loam; strongly effervescent; very strongly alkaline (pH 9.2).

TYPE LOCATION: Nye County, Nevada; about 500 feet north and 300 feet west of the projected southeast corner of section 13, T. 16 S., R. 50 E., MDBL

RANGE IN CHARACTERISTICS:

Soil moisture - Usually dry; moist during the winter and early spring; typic aridic soil moisture regime. The ratio of actual evapotranspiration between winter and summer is about 0.4:1, typical of the Mojave Desert.

Soil temperature - 63 to 69 degrees F.

Depth to duripan - 10 to 20 inches.

Reaction - Moderately alkaline to very strongly alkaline.


Control Section - Clay content: 5 to 10 percent.


A horizon - Rock fragments: 5 to 15 percent.

Boundary: Abrupt or clear.


Bk horizons - Chroma: 3 or 4 dry, 4 through 6 moist.

Structure: Weak subangular blocky or massive.

Texture: Fine sandy loam, sandy loam.

Other features: Some pedons contain small amounts of gypsum. Some pedons contain up to 10 percent pan fragments.


Bqkm horizon - Rupture resistance: Weakly to strongly cemented.


2C horizons - Texture: Stratified alluvium with variable texture and rock fragment content.

Salinity: Slightly saline or moderately saline.

COMPETING SERIES: These are the Crackerjack (CA) and Jetmine (NV). Crackerjack soils have 8 to 15 percent clay and 25 to 35 percent gravel in the control section. In addition, they have C horizons with 35 to 60 percent rock fragments below the duripan. Jetmine soils have ratios of actual evapotranspiration between summer and winter of about 0.8, typical of the Mojave Desert transitional to the Sonoran Desert. In addition, they have duripans that are more than 24 inches thick.

GEOGRAPHIC SETTING: Lewdlac soils are on dissected relict alluvial flats and have slopes of 0 to 8 percent. These soils formed in mixed alluvium dominantly from quartzite and extrusive igneous rocks over variable substrata including reworked lacustrine sediments. Elevations are 2,200 to 4,000 feet. Climate is arid, with cool winters and hot dry summers typical of the Mojave Desert. Average annual precipitation is 3 to 5 inches; average annual temperature is 63 to 68 degrees F., and the frost-free season is about 210 to 250 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alko, and Sanwell series. The Alko soils have indurated duripans and lack lacustrine influenced substrata. The Sanwell soils lack a duripan and are skeletal.

DRAINAGE AND PERMEABILITY: Well drained; very slow or slow runoff; moderately rapid permeability above the duripan.

USE AND VEGETATION: Rangeland, wildlife habitat and clay mining. The vegetation is principally shadscale with some creosotebush, wolfberry, globemallow, white bursage, and desert pepperweed.

DISTRIBUTION AND EXTENT: Southern Nevada. Lewdlac soils are not extensive. MLRA 30.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA

SERIES ESTABLISHED: Nye County, Nevada, Southwest part, 1994. The name is coined.

REMARKS: Diagnostic horizon and features recognized in this pedon are;

Ochric epipedon - the zone from the soil surface to about 3 inches (A horizon).

Duripan - The zone from about 16 to 21 inches (Bqkm horizon).

Textural control section - The zone from 10 to about 16 inches.

Responsibility for this series was transferred from Davis to Phoenix 11/2015. The last revision to the series was 1/2001. ET

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National Cooperative Soil Survey
U.S.A.