LOCATION TONOPAH                 NV+AZ

Established Series
Rev. LJL/LNL/ELS/ET
12/2015

TONOPAH SERIES

The Tonopah series consists of very deep, excessively to well drained soils that formed in mixed alluvium. Tonopah soils are on fan remnants and fan piedmonts. Slope ranges from 0 to 15 percent. The mean annual precipitation is about 6 inches and the mean annual temperature is about 65 degrees F.

TAXONOMIC CLASS: Sandy-skeletal, mixed, thermic Typic Haplocalcids

TYPICAL PEDON: Tonopah very gravelly sandy loam, rangeland and wildlife habitat. (Colors are for dry soil unless otherwise noted.)

A1--0 to 1 inch; light brown (7.5YR 6/4) very gravelly sandy loam, brown (7.5YR 4/3) moist; weak medium platy structure; soft, very friable, nonsticky and nonplastic; few very fine roots; few very fine and fine vesicular, and common very fine tubular pores; 35 percent pebbles and 15 percent cobbles; violently effervescent; moderately alkaline (pH 8.4); abrupt smooth boundary. (0 to 3 inches thick)

A2--1 to 6 inches; light brown (7.5YR 6/4) very gravelly sandy loam, brown (7.5YR 4/3) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few fine roots; many very fine and fine interstitial pores; 40 percent pebbles and 10 percent cobbles; violently effervescent; strongly alkaline (pH 8.6); gradual smooth boundary. (5 to 8 inches thick)

A3--6 to 22 inches; light brown (7.5YR 6/4) extremely gravelly sand, brown (7.5YR 5/4) moist; massive; soft, very friable, nonsticky and nonplastic; few fine roots; many very fine, fine, and few medium interstitial pores; 60 percent pebbles and 20 percent cobbles; violently effervescent; strongly alkaline (pH 8.7); clear wavy boundary. (8 to 20 inches thick)

Bk1--22 to 33 inches; light brown (7.5YR 6/4) extremely gravelly sand, brown (7.5YR 5/4) moist; massive; soft, very friable, nonsticky and nonplastic; few fine roots; many very fine and fine interstitial pores; common fine calcium carbonate coats, very pale brown (10YR 8/2), on rock fragments; weakly cemented calcium carbonate pockets and seams; 60 percent pebbles and 20 percent cobbles; violently effervescent; strongly alkaline (pH 8.9); clear wavy boundary. (8 to 24 inches thick)

Bk2--33 to 60 inches; light brown (7.5YR 6/4) extremely gravelly sand, brown (7.5YR 5/4) moist; single grain; loose, nonsticky and nonplastic; few fine roots; many very fine and fine interstitial pores; common fine calcium carbonate coats on the bottoms of rock fragments; 60 percent pebbles and 20 percent cobbles; violently effervescent strongly alkaline (pH 8.6).

TYPE LOCATION: Clark County, Nevada; about 1,320 feet west and 1,320 feet north of the southeast corner of section 22, T. 15 S., R. 65 E.

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 - 63 to 71 degrees F.

Depth to the calcic horizon - 18 to 30 inches.

Reaction - Slightly alkaline to strongly alkaline.

Control section: Texture of fine earth: Stratified, but averages sand or loamy sand.

Clay content: Average 2 to 10 percent.

Rock fragments: Averages 50 to 85 percent. Pebbles average 40 to 65 percent, cobbles average 0 to 25 percent.

A horizons - Hue: 7.5YR or 10YR.

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

Chroma: 2 through 4.

Calcium carbonate equivalent in the fine earth fraction: 1 to 15 percent.

Bk horizons - Hue: 7.5YR or 10YR.

Value: 6 through 8 dry, 3 through 7 moist.

Chroma: 2 through 4, dry or moist.

Calcium carbonate equivalent in the fine earth fraction: 10 to 40 percent.

Other features: Bk subhorizons have 5 to 15 percent secondary calcium carbonate and coats on rock fragments and/or filaments or masses.

COMPETING SERIES: These are the Caliza (NM), Eastland (NV), Niavi (NV), Redo (AZ), Shelley (AZ) and Zevac (TX) series. Caliza, Redo and Shelley soils have a calcic horizon at depths of 1 to 18 inches. Eastland soils have a calcic horizon at depths of 30 to 40 inches. These soils are not moist for 10 to 20 dayscumulative between July and October. Niavi soils have Bw horizons, have mean annual soil temperature of 59 to 64 degrees and calcium carbonate equivalent of the Bk horizons is 1 to 10 percent. Zevac soils have a calcic horizon at 0 to 5 inches and 35 to 50 percent rack fragments in the particle-size control section.

GEOGRAPHIC SETTING: Tonopah soils are on fan remnants and fan piedmonts. These soils formed in mixed alluvium. Slope ranges from 0 to 15 percent. Elevations are 1,500 to 3,400 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 2 to 8 inches; mean annual temperature is 61 to 69 degrees F., and the frost-free season is 180 to 300 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bard, Toquop, and St. Thomas soils. Bard soils have a petrocalcic horizon. Toquop soils have a sandy control section and lack a calcic horizon. St. Thomas soils have a lithic contact at 4 to 19 inches.

DRAINAGE AND PERMEABILITY: Excessively to well drained; very low through medium runoff; moderately 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, southeastern California and western Arizona; MLRA 30. These soils are moderately extensive.

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

SERIES ESTABLISHED: Clark County (Las Vegas Area), Nevada, 1923.

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

Ochric epipedon - 0 to 7 inches (A1, A2, and part of the A3 horizon)

Calcic horizon - 22 to 60 inches (Bk1 and Bk2 horizon)

Particle-size control section - 10 to 40 inches (part of the A3, Bk1 and part of the Bk3 horizon)

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 4/2006. ET

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National Cooperative Soil Survey
U.S.A.