LOCATION ARROLIME                NV

Established Series
Rev. LNL/ELS/ET
04/2015

ARROLIME SERIES

Arrolime soils have pink A1 horizons about 2 inches thick and Ccsca horizons within 5 inches of the soil surface. They are calcareous and moderately and very strongly alkaline.

TAXONOMIC CLASS: Loamy-skeletal, mixed, active, thermic Typic Calcigypsids

TYPICAL PEDON: Arrolime gravelly silt loam, rangeland. Colors are for dry soil unless otherwise noted.) The soil surface has a strongly developed gravel pavement with channery shaped limestone and sandstone gravel oriented with their long axis parallel to the soil surface. A few exposed surfaces have a burnished desert varnish.

A1--0 to 2 inches; pink (7.5YR 7/4) gravelly silt loam, brown (7.5YR 4/4) moist; weak thick platy structure; hard, friable, slightly sticky and slightly plastic; few very fine roots; many fine and very fine vesicular pores; violently effervescent; very strongly alkaline (pH 9.4); abrupt smooth boundary. (1 to 3 inches thick)

C1--2 to 5 inches; reddish yellow (5YR 6/6) silty clay loam, yellowish red (5YR 4/6) moist; strong medium platy structure; slightly hard, very friable, sticky and plastic; few very fine and fine roots; few very fine tubular and common very fine and fine interstitial pores; very few thin reddish brown (5YR 5/4) clay films on pebbles and few colloids in bridges between sand grains; 10 percent gravel; violently effervescent; strongly alkaline (pH 9.0); abrupt wavy boundary. (2 to 5 inches thick)

C2csca--5 to 15 inches; pink (7.5YR 7/4) gravelly silt loam, yellowish brown (5YR 5/6) moist; many coarse prominent pinkish white (5YR 8/2) gypsum and lime mottles and soft nodules; moderate very fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine, and few fine and medium roots; many very fine interstitial pores; 30 percent gravel; violently effervescent; moderately alkaline (pH 8.2) ; clear wavy boundary. (8 to 15 inches thick)

IIC3csca--15 to 36 inches; pink (5YR 7/4) very gravelly silt loam; yellowish red (5YR 5/6) moist; many coarse prominent pinkish white (5YR 8/2) gypsum and lime mottles and soft nodules; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular and interstitial pores; 70 percent gravel; violently effervescent; moderately alkaline (pH 8.4); gradual wavy boundary. (12 to 24 inches thick)

IIC4--36 to 49 inches; light reddish brown (5YR 6/4) very gravelly clay loam; yellowish red (5YR 4/6) and dark reddish brown (5YR 3/4) moist; few coarse distinct reddish brown (5YR 4/4) mottles; massive; very hard, friable, sticky and plastic; few very fine tubular and many very fine interstitial pores; 70 percent gravel; violently effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (8 to 15 inches thick)

IIIC5cs--49 to 62 inches; mixed red (2.5YR 5/6) and light reddish brown (5YR 6/4) light silty clay loam; red (2.5YR 4/6) moist; fine, medium and coarse distinct pink (5YR 8/4 and 7.5YR 8/4) soft gypsum nodules and mottles; massive; very hard, friable, sticky and plastic; many very fine interstitial pores; 10 percent gravel and 60 percent gypsum; violently effervescent; slightly alkaline (pH 7.6).

TYPE LOCATION: Clark County, Nevada; in Valley of Fire Nevada State Park, approximately 700 feet north and 1,500 feet of the SW corner of section 13, T.16S., R.66E., Mount Diablo base line and meridian.

RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 59 to 66 degrees F. These soils usually are dry for 6 months or more during most years, mainly during the spring, summer and autumn. The A1 horizon has 0.10 to 0.30 percent organic matter. The soil profile except for the Cca horizon has hue of 5YR or 7.5YR, value of 5 through 7 dry, 4 or 5 moist, and chroma of 4 through 6. The 10 to 40 inch control section is silt loam, silty clay loam, and clay loam modified by 50 to 80 percent gravel. The gravel is less than 2 inches in diameter, averageing about 3/4 inch and is rounded or subrounded. Lime mottles, stains, and soft nodules occur in any horizon below the A1 horizon, and are medium or coarse. pH ranges from 8.6 to 9.6 except in the Ccs horizon where pH ranges from 7.0 to 8.4. The Ccs horizon has hue of 2.5YR through 10YR, value of 5 through 8 dry, 4 through 6 moist, and chroma of 1 through 6. It is 3 to 10 inches below the surface and is 24 to 40 inches thick. The gypsum is disseminated or segregated and is in the form of very fine crystals or coarse soft nodules.

COMPETING SERIES: These are the Aztec, Bracken, McCarren, Nickel, and Weiser series. Aztec soils have moderately coarse and coarse textures and gypsic horizons weakly cemented in some subhorizons. Bracken and McCarren soils have coarse, loamy control sections. Nickel and Weiser soils lack gypsic horizons.

GEOGRAPHIC SETTING: Arrolime soils are on strongly dissected old alluvial fans with smooth to slightly convex, gently sloping (2 to 4 percent gradient) side slopes. These soils formed in highly gypsiferous alluvium derived mainly from gypsum with some admixture from limestone, sandstone, and other sedimentary rocks. The climate is arid, having a mean annual precipitation of 4 to 6 inches. The temperatures are hot, having a mean annual precipitation of about 63 degrees F.; the mean January temperature is about 43 degrees F.; and the mean July temperature is about 83 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Moapa, Bard, and St Thomas soils. Moapa soils have sandy control sections and formed in residuum from sandstone. Bard soils have thick petrocalcic horizons. St Thomas soils are shallow over limestone.

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

USE AND VEGETATION: These soils are used for range. The principal native plants are creosotebush and white bursage with some annuals.

DISTRIBUTION AND EXTENT: Southeastern Nevada, but may also occur in adjacent states where the parent rocks are similar. MLRA 30. The series is of small extent.

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

SERIES ESTABLISHED: Virgin River Area, Nevada-Arizona, 1970.

REMARKS: Arrolime soils were formerly classified as Gypsic Solonchak soils. It latter was classified as loamy-skeletal, mixed, thermic Leptic Haplogypsids. The classification was again revised in March of 2003 recognizing the calcic horizon above the gypsic and adding the CEC activity class using the second edition to Soil Taxonomy. Competing series were not checked at that time. -ET

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 3/2003. ET

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National Cooperative Soil Survey
U.S.A.