LOCATION GYPWASH                 NV

Established Series
Rev. DJM-JVC
04/2015

GYPWASH SERIES

The Gypwash series consists of very deep, somewhat excessively drained soils that formed in alluvium derived dominantly from limestone. Gypwash soils are on fan remnants. Slope ranges from 2 to 15 percent. The mean annual precipitation is about 5 inches and the mean annual temperature is about 72 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, carbonatic, hyperthermic Typic Calcigypsids

TYPICAL PEDON: Gypwash extremely gravelly fine sandy loam, rangeland and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by a desert pavement of approximately 65 percent pebbles and 5 percent cobbles.

A--0 to 1 inch; light brown (7.5YR 6/4) extremely gravelly fine sandy loam, brown (7.5YR 4/4) moist; strong very thick platy structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; many very fine, common fine, and common medium vesicular pores; 65 percent pebbles and 5 percent cobbles; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (1 to 3 inches thick)

Bw--1 to 4 inches; light brown (7.5YR 6/4) gravelly fine sandy loam, brown (7.5YR 4/4) moist; moderate medium platy structure; slightly hard, very friable, slightly sticky and nonplastic; common very fine roots; many very fine and common fine vesicular pores; 25 percent pebbles; violently effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (0 to 3 inches thick)

Bky1--4 to 12 inches; reddish brown (5YR 5/4) extremely gravelly coarse sandy loam, reddish brown (5YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; common interstitial and few very fine tubular pores; 20 percent coarse soft calcium carbonate masses and many fine coats on bottom of rock fragments; 1 percent fine gypsum crystals on bottom of rock fragments; 60 percent pebbles; violently effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary.

Bky2--12 to 27 inches; reddish brown (5YR 5/4), stratified very gravelly coarse sand and extremely gravelly coarse sandy loam, reddish brown (5YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; many very fine interstitial and common fine and medium tubular pores; 5 percent coarse soft calcium carbonate masses and many medium coats and pendants on bottom of rock fragments; 2 percent fine gypsum crystals on bottom of rock fragments; 65 percent pebbles; violently effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (Combined thickness of the Bky horizons is 22 to 27 inches.)

Byk1--27 to 36 inches; reddish brown (5YR 5/4) stratified extremely gravelly gypsiferous coarse sandy loam and very gravelly gypsiferous sandy loam, reddish brown (5YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; many very fine and fine interstitial pores; common fine calcium carbonate coats on bottom of rock fragments; many (35 percent) 2 to 70 millimeter gypsum pendants on bottom of rock fragments; 75 percent pebbles; violently effervescent; moderately alkaline (pH 8.2) abrupt wavy boundary. (7 to 10 inches thick)

Byk2--36 to 61 inches; light reddish brown (5YR 6/4) stratified very gravelly gypsiferous coarse sand and extremely gravelly gypsiferous coarse sandy loam, reddish brown (5YR 4/4) moist; massive; slightly hard, very friable, nonsticky and nonplastic; many very fine and fine interstitial pores; common fine calcium carbonate coats on bottom of rock fragments; common (15 percent) 1 to 30 millimeter gypsum pendants on bottom of rock fragments; averages about 65 percent pebbles; violently effervescent; moderately alkaline (pH 8.2).

TYPE LOCATION: Clark County, Nevada; about 9.5 miles northeast of Henderson in the Lake Mead National Recreation Area and about 0.75 mile north of the junction of Northshore Road and Lake Mead Boulevard; 1,875 feet south and 640 feet west of the northeast corner of section 1, T. 21 S., R. 63 E.; USGS Frenchman Mountain, NV 7.5 minute topographic quadrangle; 36 degrees 09 minutes 15 seconds north latitude and 114 degrees 53 minutes 21 seconds west longitude; UTM 11s, 689887e, 4003112n; NAD 83.

RANGE IN CHARACTERISTICS:

Soil moisture - Usually dry, moist in some part during winter and spring and intermittingly moist in the upper part following summer convection storms; typic aridic soil moisture regime.

Mean annual soil temperature - 72 to 78 degrees F.

Depth to calcic horizon - 3 or 4 inches.

Depth to gypsic horizon - 25 to 30 inches.

Control section - Clay content: 4 to 10 percent

Rock fragments: 55 to 80 percent, mainly gravel.

Calcium carbonate equivalent in the less than 20 millimeter fraction - 40 to 60 percent.

A horizon - Hue: 5YR through 10YR.
Chroma: 3 or 4, dry or moist.
Calcium carbonate equivalent in the fine earth fraction: 20 to 40 percent.

Bky horizons - Hue: 5YR through 10YR.
Value: 5 or 6 dry.
Chroma: 3 or 4, dry or moist.
Texture: Sandy loam, sandy loam, or coarse sandy loam.
Clay content: 4 to 10 percent.
Calcium carbonate equivalent in the fine earth fraction: 30 to 40 percent.
Gypsum content: 0 to 3 percent.


Byk horizons - Hue: 5YR through 10YR.
Chroma: 3 or 4, dry or moist.
Texture: Averages gypsiferous coarse sandy loam through gypsiferous sandy loam, includes layers of coarse sand or loamy coarse sand in the lower part.
Clay content: 4 to 8 percent.
Consistence: Soft or slightly hard.
Effervescence: Strongly effervescent or violently effervescent
Calcium carbonate equivalent in the fine earth fraction: 30 to 50 percent.
Gypsum content: 15 to 35 percent.

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

GEOGRAPHIC SETTING: Gypwash soils are on fan remnants. They typically occur on summit positions. These soils formed in alluvium derived from limestone, dolostone, and gypsum rock. Slope ranges from 2 to 15 percent. Elevations are 1,200 to 2,500 feet. The climate is low-latitude desert, with mild winters and very hot summers. Precipitation is greatest in the winter with lesser secondary peak in the summer, typical of the Mojave Desert transitional to Sonoran Desert. The mean annual precipitation is 3 to 7 inches, the mean annual temperature is 70 to 74 degrees F., and the frost-free period is 300 to 360 days.

GEOGRAPHICALLY ASSOCIATED SOILS: This is the Guardian soil. Guardian soils are loamy, shallow to paralithic contacts, and have gypsic horizons and gypsic mineralogy.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; low runoff; moderately rapid permeability.

USE AND VEGETATION: These soils are used for rangeland and wildlife habitat. The present vegetation is mainly white bursage and creosotebush.

DISTRIBUTION AND EXTENT: Mojave Desert of southern Nevada. MLRA 30;. These soils are not extensive.

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

SERIES ESTABLISHED: Clark County Area, Nevada, 2006. Proposed in Clark County, Nevada, 1998. The name is from a nearby wash.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - 0 to 4 inches (A and Bw horizons).

Calcic horizon - 4 to 61 inches (Bky1, Bky2, Byk1 and Byk2 horizons).

Gypsic horizon - 27 to 61 inches (Byk1 and Byk2 horizons).

Particle-size control section - 10 to 40 inches (Bky1 and Bky2 horizons and parts of the Byk1 and Byk2 horizons).

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 7/2006. ET

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National Cooperative Soil Survey
U.S.A.