LOCATION RAILROAD                NV

Established Series
Rev. LJL/TM/ET
12/2015

RAILROAD SERIES

The Railroad series consists of moderately deep, well drained soils that formed in colluvium and residuum from unspecified volcanics influenced by calcareous loess. Railroad soils are on basalt lava flows and mountains. Slope ranges from 4 to 50 percent. The mean annual precipitation is about 6 inches and the mean annual temperature is about 60 degrees F.

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

TYPICAL PEDON: Railroad extremely stony sandy loam, rangeland and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered by approximately 35 percent pebbles, 15 percent cobbles and 15 percent stones.

A--0 to 3 inches; pale brown (10YR 6/3) extremely stony sandy loam, brown (10YR 4/3) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and few fine roots; many very fine and few fine and medium interstitial and tubular pores; 35 percent pebbles, 15 percent cobbles and 15 percent stones; strongly effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (2 to 4 inches thick)

Bw--3 to 11 inches; very pale brown (10YR 7/3) very gravelly fine sandy loam, yellowish brown (10YR 5/4) moist; moderate fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots; many very fine and fine tubular pores; 40 percent pebbles (including indurated duripan fragments) and 5 percent cobbles; strongly effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (6 to 10 inches thick)

Bkq1--11 to 15 inches; pink (7.5YR 7/4) very gravelly fine sandy loam, brown (7.5YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine and fine roots; many very fine and fine tubular pores; common fine calcium carbonate pendants on undersides of rock fragments; 35 percent pebbles (including indurated duripan fragments); strongly effervescent; moderately alkaline (pH 8.4); clear smooth boundary.

Bkq2--15 to 27 inches; light yellowish brown (10YR 6/4) very gravelly fine sandy loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine and fine roots; many very fine and fine tubular pores; common fine calcium carbonate coats and medium calcium carbonate pendants on undersides of rock fragments; 45 percent pebbles (including indurated duripan fragments); violently effervescent; moderately alkaline (pH 8.4); clear smooth boundary.

Bkq3--27 to 34 inches; light yellowish brown (10YR 6/4) very gravelly fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; common very fine and fine roots; many very fine and fine tubular pores; many medium calcium carbonate pendants on undersides of rock fragments, common fine soft filaments of calcium carbonate; 40 percent pebbles (including indurated duripan fragments); violently effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (Combined thickness of Bkq horizons is 10 to 30 inches)

R--34 inches; hard basalt bedrock;

TYPE LOCATION: Clark County, Nevada; approximately 9 miles east-southeast of Sloan, NV and 4 miles southwest of Black Mountain located in the McCullough Range; about 1,510 feet east and 2,015 feet south of the northwest corner of section 5, T. 24 S., R. 62 E.; USGS Sloan NE, NV 7.5 minute topographic quadrangle; 35 degrees, 53 minutes, 26 seconds north latitude and 115 degrees, 04 minutes, 20 seconds west longitude; UTM 11, 673997e, 3973527n; 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 thunderstorms; Has a typic-aridic moisture regime.

Soil temperature - 59 to 65 degrees F.

Depth to calcic horizon - 10 to 20 inches.

Depth to lithic contact - 30 to 40 inches.

Control section - Percent clay: 6 to 16 percent.

Rock fragments: 35 to 60 percent, mainly pebbles and some duripan fragments.

A horizon - Calcium carbonate equivalent in the fine earth fraction: 5 to 15 percent.

Bw horizon Hue: 10YR or 7.5YR.

Value: 4 or 5 moist.

Chroma: 3 or 4 dry and moist.

Rock fragments: 35 to 60 percent, dominated by gravels and some duripan fragments with 0 to 15 percent cobbles.

Consistence: Nonsticky or slightly sticky.

Calcium carbonate equivalent in the fine earth fraction: 5 to 15 percent.

Bkq horizons Hue: 7.5YR or 10YR.

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

Chroma: 3 or 4 dry and moist.

Texture: Fine sandy loam or loam.

Structure: Subangular blocky or massive.

Consistence: Soft or slightly hard, very friable or friable, nonsticky or slightly sticky and nonplastic or plastic.

Reaction: Moderately alkaline or strongly alkaline.

Calcium carbonate equivalent in the fine earth fraction: 15 to 30 percent.

Other features: Some pedons have discontinuous weak calcium carbonate cementation.

COMPETING SERIES: These are the Alemeda (NM), Chamberino (NM), Corazones (TX), Dime (CA), Nickel (NV), Piquin (NM) and Stagecoach (AZ) series. Alemeda soils contain 5 to 25 percent rock fragment in the cambic horizon and receives most of the precipitation in the summer. Chamberino, Corazones, Dime, Nickel, Piquin and Stagecoach soils are all deeper than 60 inches to bedrock.

GEOGRAPHIC SETTING: Railroad soils are on basalt lava flows and mountains. These soils formed in colluvium and residuum from unspecified volcanics influenced by calcareous loess. Slope ranges from 4 to 50 percent. Elevations are 2,500 to 5,000 feet. The climate is low-latitude desert, with mild winters and very hot summers. Precipitation is greatest in the summer, typical of the Mojave Desert. The mean annual precipitation is 5 to 7 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 Haleburu and Nipton series. Haleburu and Nipton soils are less than 20 inches deep to bedrock and lack a calcic horizon.

DRAINAGE AND PERMEABILITY: Well drained; high runoff; moderately rapid permeability.

USE AND VEGETATION: These soils are used for rangeland and wildlife habitat. The present vegetation is mainly big galleta, bush muhly, winterfat, Nevada ephedra and creosotebush.

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, 1994. The name is coined.

REMARKS: Reclassified according to Keys to Soil Taxonomy (6th ed., 1994). Diagnostic horizons and features recognized in this pedon are:

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

Cambic horizon - 3 to 11 inches (Bw horizon)

Calcic horizon - 11 to 34 inches (Bkq1, Bkq2 and Bkq3 horizons).

Particle-size control section - 10 to 34 inches (Part of the Bw, Bkq1, Bkq2 and Bkq3 horizons).

Lithic contact - 34 inches (R layer).

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 7/2006. ET

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National Cooperative Soil Survey
U.S.A.