LOCATION HYPOINT                 NV+CA

Established Series
Rev. LJL/JLL/ET
04/2015

HYPOINT SERIES

The Hypoint series consists of very deep, somewhat excessively drained soils that formed in mixed alluvium. Hypoint soils are on fan aprons, fan skirts and alluvial fans. Slope ranges from 0 to 15 percent. The mean annual precipitation is about 6 inches and the mean annual air temperature is about 66 degrees F.

TAXONOMIC CLASS: Sandy, mixed, thermic Typic Torriorthents

TYPICAL PEDON: Hypoint gravelly sandy loam, rangeland and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 20 percent pebbles.

A--0 to 2 inches; pale brown (10YR 6/3) gravelly sandy loam, brown (10YR 4/3) moist; weak medium subangular blocky structure, with a 1/4 inch surface crust; soft, very friable, nonsticky and nonplastic; common very fine roots; common very fine interstitial and few fine tubular pores; 20 percent pebbles; slightly effervescent; moderately alkaline (pH 8.4); clear smooth boundary. (2 to 4 inches thick)

C--2 to 60 inches; pale brown (10YR 6/3) and light yellowish brown (10YR 6/4) stratified sand to very gravelly coarse sand, brown (10YR 4/3) and dark yellowish brown (10YR 4/4) moist; massive; soft, very friable, nonsticky and nonplastic; common very fine and few fine roots; few very fine through coarse tubular and common very fine and fine interstitial pores; few, distinct, nonoriented patches of calcium carbonate coats on rock fragments; averages 25 percent pebbles; slightly effervescent; strongly alkaline (pH 8.6); .

TYPE LOCATION: Clark County, Nevada; approximately 1 mile west of Eldorado Valley Dry Lake; about 1,960 feet south and 230 feet east of the northwest corner of section 17, T. 24 S., R. 63 E.; USGS Boulder City SW, NV 7.5 minute topographic quadrangle; 35 degrees, 51 minutes, 38 seconds north latitude and 114 degrees, 58 minutes, 22 seconds west longitude; UTM 11s, 683043e, 3970381n; NAD 83.

RANGE IN CHARACTERISTICS:

Soil moisture - Usually dry, moist in some part for short periods during winter and early spring and for 10 to 20 days cumulative between July to October following convection storms.

Soil temperature - 64 to 71 degrees F.

Control section - Rock fragments: Averages 15 to 35 percent.

Percent clay: 1 to 8 percent.

Effervescence: Noneffervescent to slightly effervescent.

A horizon - Value: 6 or 7 dry.

Chroma: 2 through 4.

C horizon - Value: 5 or 6 dry.

Rock fragments: Averages 15 to 35 with individual strata ranging up to 60 percent.

Structure: Massive or single grained.

Consistence: Soft, very friable or loose.

Other features: 1 to 3 percent randomly oriented, patchy calcium carbonate coats on rock fragments.

Calcium carbonate equivalent in the fine earth fraction: 0 to 5 percent.

COMPETING SERIES: These are the Amole T(AZ), Challenger (CA), Livefire (CA), Orwash (NV), Redington (AZ), Shortbread (AZ) and Yellowrock (CA) series. Amole soils have no layers with more than 35 percent rock fragments and contain a high content of biotite and magnetite. Amole soils are in the 8 to 12 inch precipitation zone. Challenger soils are dry within the soil moisture control section from July through September. Livefire soils have 5 to 35 percent rock fragments and sandy loam texures in the particle-size control section. Orwash soils are dominated by coarse sands and 2 to 5 mm pebbles and have a mean annual soil temperature of 59 to 63 degrees F. Redington soils have brittle dense layers and more than 20 percent rock fragments in all horizons. Shortbread soils have 0 to 15 percent rock fragments in the particle-size control section. Yellowrock soils are dry from May through November and do not receive the 10 to 20 days of summer precipitation.

GEOGRAPHIC SETTING: Hypoint soils are on fan aprons and fan skirts. These soils formed in mixed alluvium. Slope ranges from 0 to 15 percent. Elevations are 1,700 to 4,100 feet. The climate is hot and arid with warm, moist winters and hot, dry summers. The mean annual precipitation is 2 to 7 inches; mean annual air temperature is 62 to 70 degrees F., and the frost-free season is 240 to 340 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Arizo, Grapevine and Tipnat series. Arizo soils have sandy-skeletal particle size control section. Grapevine soils have calcic horizons and a coarse-loamy particle size control section. Tipnat soils have an argillic horizon and a fine-loamy particle size control section.

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

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

DISTRIBUTION AND EXTENT: Mojave Desert of southern Nevada. MLRA 30. These soils are moderately extensive.

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

SERIES ESTABLISHED: Clark County, Nevada, 1995. The name is coined.

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

Ochric epipedon - 0 to 2 inches (A horizon).

Particle-size control section - 10 inches to 40 inches (Part of the C horizon).

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 2/2006. ET

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National Cooperative Soil Survey
U.S.A.