LOCATION HELEWEISER              NV

Established Series
Rev. DJM/LJL/JVC
04/2015

HELEWEISER SERIES

The Heleweiser series consists of very deep, well drained soils that formed in mixed alluvium. Heleweiser soils are on fan remnants. Slope ranges from 2 to 50 percent. The mean annual precipitation is about 5 inches and the mean annual temperature is about 72 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, hyperthermic Typic Haplocalcids

TYPICAL PEDON: Heleweiser very gravelly sandy loam, rangeland and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 50 percent pebbles and 2 percent cobbles.

A--0 to 1 inch; light brown (7.5YR 6/4) very gravelly sandy loam, brown (7.5YR 4/4) moist; moderate medium platy structure; soft, very friable, slightly sticky and nonplastic; few very fine roots; common very fine vesicular pores; 50 percent pebbles and 2 percent cobbles; violently effervescent; moderately alkaline (pH 8.2); abrupt smooth boundary. (1 to 3 inches thick)

Bw--1 to 5 inches; light brown (7.5YR 6/4) gravelly fine sandy loam, brown (7.5YR 4/4) moist; moderate fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; common very fine roots; few very fine tubular pores and common very fine interstitial pores; 30 percent pebbles; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (0 to 4 inches thick)

Bk1--5 to 11 inches; light brown (7.5YR 6/4) gravelly fine sandy loam, brown (7.5YR 5/4) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; many very fine and few fine roots; few very fine tubular pores and common very fine interstitial pores; common (3 percent) fine soft filaments of calcium carbonate in the matrix; common fine pendants on the bottom of rock fragments; 30 percent pebbles; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (6 to 8 inches thick)

Bk2--11 to 20 inches; light brown (7.5YR 6/4) very gravelly sandy loam; brown (7.5YR 5/4) moist; massive; soft, very friable, slightly sticky and nonplastic; many very fine and few fine roots; many very fine interstitial pores; common (20 percent) coarse disseminated soft masses of calcium carbonate; common coarse pendants of calcium carbonate on the bottom of rock fragments; 50 percent pebbles; violently effervescent; strongly alkaline (pH 8.6); abrupt wavy boundary. (8 to 13 inches thick)

Bky1--20 to 34 inches; pink (7.5YR 7/4) very gravelly coarse sandy loam, brown (7.5YR 5/4) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; many very fine interstitial pores; common (15 percent) coarse calcium carbonate pendants on bottom of rock fragments; very few (1 percent) fine gypsum pendants on bottom of rock fragments; 50 percent pebbles; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (12 to 27 inches thick)

Bky2--34 to 68 inches; pink (7.5YR 7/3) stratified very gravelly coarse sandy loam and extremely gravelly loamy coarse sand, brown (7.5YR 5/4) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; many very fine interstitial pores; common (10 percent) coarse calcium carbonate pendants on bottom of rock fragments; few (1 percent) fine gypsum pendants on bottom of rock fragments; 60 percent pebbles; violently effervescent; moderately alkaline (pH 8.4).

TYPE LOCATION: Clark County, Nevada; about 11 miles northeast of Henderson in the Lake Mead National Recreation Area; in a nonsectionized township about 510 feet east and 1750 south of the northwest corner of section 15, T. 21 S., R. 64 E.; USGS Government Wash, NV 7.5 minute topographic quadrangle; 36 degrees, 8 minutes, 1 second north latitude and 114 degrees, 49 minutes, 20 seconds west longitude; UTM 11, 695962e, 4000965n; 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.

Soil temperature - 72 to 78 degrees F.

Depth to calcic horizon - 5 to 14 inches.

Control section - Clay content: Averages 5 to 10 percent.

Rock fragments: Averages 45 to 75 percent, mainly gravel.

A horizon - Hue: 7.5YR or 10YR.

Value: 6 or 7 dry, 4 or 5 moist.

Chroma: 3 or 4, dry or moist.

Calcium carbonate equivalent in the fine earth fraction: 2 to 5 percent.

Bw horizon (when present) - Hue: 7.5YR or 10YR.

Value: 6 or 7 dry, 4 through 6 moist.

Chroma: 3 or 4, dry or moist.

Texture: Sandy loam and fine sandy loam.

Rock fragments: 15 to 35 percent.

Bk1 horizon - Hue: 7.5YR or 10YR.

Value: 6 or 7 dry, 4 through 6 moist.

Chroma: 3 or 4, dry or moist.

Texture: Sandy loam and fine sandy loam.

Rock fragments: 15 to 55 percent.

Calcium carbonate equivalent in the fine earth fraction: 5 to 20 percent.

Bk2 horizon - Hue: 7.5YR or 10YR.

Value: 6 through 8 dry, 4 through 6 moist.

Chroma: 3 or 4, dry or moist.

Texture: Sandy loam and coarse sandy loam.

Reaction: Moderately alkaline or strongly alkaline.

Calcium carbonate equivalent in the fine earth fraction: 10 to 30 percent.

Bky horizons - Hue: 5YR through 10YR.

Value: 6 or 7 dry, 4 through 6 moist.

Chroma: 3 or 4, dry or moist.

Texture: Averages coarse sandy loam or sandy loam, includes strata of loamy sand and loamy coarse sand in the lower part.

Rock fragments: 45 to 75 percent.

Calcium carbonate equivalent in the fine earth fraction: 10 to 30 in the upper part and 5 to 20 percent in the lower part.

Gypsum content: 1 to 3 percent.

COMPETING SERIES: They are the Gunsight and Chemehuevi series. Gunsight soils do not have secondary gypsum in the lower part of the control sections. Chemehuevi soils have a soil temperature of 78 to 83 degrees.

GEOGRAPHIC SETTING: Heleweiser soils are on fan remnants. They typically occur on summit positions. These soils formed in mixed alluvium. Slope ranges from 2 to 50 percent. Elevations are 1,150 to 2,700 feet. The climate is low latitude desert, with mild winters and very hot summers. Precipitation is greatest in the winter with a lesser secondary peak in summer typical of the Mojave Desert. The mean annual precipitation is 3 to 7 inches, the mean annual temperature is 70 to 75 degrees F., and the frost-free period is 300 to 360 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carrizo and Teebar (T) soils. Carrizo soils are sandy-skeletal and do not have diagnostic subsurface horizons. Teebar soils are loamy-skeletal, very shallow to petrocalcic horizons, and have carbonatic mineralogy.

DRAINAGE AND PERMEABILITY: Well drained; very low or low runoff; moderately rapid permeability.

USE AND VEGETATION: These soils are used for rangeland and wildlife habitat. The present vegetation is mainly creosotebush, white bursage, range ratany, King's desertgrass and big galleta.

DISTRIBUTION AND EXTENT: Mojave Desert of southeastern 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, 1997. The name is coined.

REMARKS: The superactive cation exchange activity class is estimated. Laboratory data is needed to confirm this placement.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - 0 to 7 inches (A, Bw and part of the Bk1 horizons).

Calcic horizon - 11 to 34 inches (Bk2 and Bky1 horizons).

Particle size control section - 10 to 40 inches (Bk2 and Bky1 and parts of the Bk1 and Bky2 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.