LOCATION HOPPSWELL               NV

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

HOPPSWELL SERIES

The Hoppswell series consists of very deep, well drained soils that formed in alluvium from igneous sources. Hoppswell soils are on fan remnants. Slope ranges from 2 to 15 percent. The mean annual precipitation is about 8 inches and the mean annual temperature is about 61 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Ustic Haplargids

TYPICAL PEDON: Hoppswell extremely gravelly sandy loam, rangeland and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 70 percent pebbles, 5 percent cobbles and 3 percent stones.

A--0 to 2 inches; brown (7.5YR 5/4) extremely gravelly sandy loam, dark brown (7.5YR 3/4) moist; moderate medium and thick platy structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; common very fine and fine vesicular pores; 70 percent pebbles, 5 percent cobbles and 3 percent stones; moderately alkaline (pH 8.0); abrupt smooth boundary. (1 to 4 inches thick)

Bt--2 to 15 inches; yellowish red (5YR 5/6) very gravelly sandy clay loam, yellowish red (5YR 4/6) moist; moderate fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; many very fine and fine interstitial pores; many distinct clay films on faces of peds and few faint clay films lining pores; 50 percent pebbles; moderately alkaline (pH 8.0); abrupt wavy boundary. (10 to 21 inches thick)

Bk--15 to 64 inches; white (10YR 8/1) stratified extremely gravelly coarse sand to very gravelly sandy loam, brown (10YR 5/3) moist; massive; slightly hard, friable, nonsticky and nonplastic; common very fine, fine, and few medium and coarse roots; common very fine and fine interstitial pores and few medium tubular pores; many thin calcium carbonate coats on the undersides of coarse fragments; many thin calcium carbonate filaments on the tops of coarse fragments; averages 60 percent pebbles; violently effervescent; strongly alkaline (pH 8.6).

TYPE LOCATION: Clark County, Nevada; approximately 9 miles southeast of McCullough Pass between the McCullough Range and the Highland Range on the west side of the powerline road; about 1280 feet west and 625 feet north of the southeast corner of section 6, T. 27 S., R. 62 E.; USGS Highland Spring, NV 7.5 minute topographic quadrangle; 35 degrees, 37 minutes, 4 seconds north latitude and 115 degrees, 5 minutes, 3 seconds west longitude; UTM 11, 673508e, 3943247n; NAD 83.

RANGE IN CHARACTERISTICS:

Soil moisture - Usually dry, moist in some part from December to March and intermittently moist for 10 to 20 days during July to October following summer convection storms; aridic moisture regime bordering on ustic.

Soil temperature - 59 to 65 degrees F.

Depth to base of argillic - 11 to 25 inches.

Control section - Percent clay: 20 to 30 percent.
Rock fragments: 35 to 60 percent, mainly gravel.

A horizon - Hue: 10YR or 7.5YR.
Value: 5 or 6 dry.


Bt horizon - Hue: 7.5YR or 5YR.
Value: 4 or 5 dry.
Chroma: 4 through 6 dry.
Structure: Weak or moderate, fine or medium, subangular blocky or massive.
Consistence: Slightly hard or hard, friable or very friable, nonsticky to moderately sticky, nonplastic to moderately plastic.

Bk horizons - Hue: 10YR or 7.5YR.
Value: 6 through 8 dry, 4 or 5 moist.
Chroma: 1 through 4 dry, 3 or 4 moist.
Clay content: 3 to 12 percent.
Texture: Usually dominated by loamy sand.
Consistence: Soft to hard, friable to firm; nonsticky or slightly sticky, and nonplastic or slightly plastic.
Rock fragments: 50 to 70 percent, mainly gravel.
Effervesence: Strongly effervescent or violently effervesecent.
Reaction: Moderately alkaline or strongly alkaline.
Calcium carbonate in the fine earth fraction: 1 to 10 percent.
Other: common to many calcium carbonate coats on coarse fragments and many large irregular pockets of disseminated calcium carbonate in some horizons.

COMPETING SERIES: These are the Caralampi (AZ), Coxwell (NM), Holliday (NM), Maloy (AZ) series. Maloy soils are dominated by cobbles and/or stones. Caralampi soils are noneffervescent in the upper 40 inches. Coxwell soils are 20 to 40 inches deep to paralithic contact. Holliday soils receive more than 20 days of summer precipitation.

GEOGRAPHIC SETTING: Hoppswell soils are on fan remnants. These soils formed in alluvium from igneous sources. Slope ranges from 2 to 15 percent. Elevations are 3,300 to 5,200 feet. The climate is hot and arid with warm, moist winters and hot, dry summers. The mean annual precipitation is 7 to 9 inches; mean annual temperature is 57 to 63 degrees F., and the frost-free season is 180 to 240 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lanfair and Ustidur series. Lanfair soils have a sandy-skeletal control section and a cambic horizon. Ustidur soils have a duripan and do not have an argillic horizon.

DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderately slow permeability.

USE AND VEGETATION: These soils are used for rangeland and wildlife habitat. The present vegetation is mainly blackbrush, Spanish dagger, black grama, galleta and desert needlegrass.

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, 1993. The name is coined from Hopps Well located 10 miles to the south.

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

Ochric epipedon 0 to 2 inches (A horizon).

Argillic horizon - 2 to 15 inches (Bt horizon).

Particle-size control section - 2 to 15 inches (Bt horizon).

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.