LOCATION MOUNTMCULL              NV

Established Series
Rev. LJL/RLB/TM
11/2015

MOUNTMCULL SERIES

The Mountmcull series consists of very shallow, somewhat excessively drained soils that formed in residuum and colluvium from metamorphosed granitic sources. Mountmcull soils are on mountains. Slope ranges from 30 to 75 percent. The mean annual precipitation is about 8 inches and the mean annual temperature is about 54 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, nonacid, mesic Lithic Ustic Torriorthents

TYPICAL PEDON: Mountmcull extremely gravelly sandy loam, rangeland and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 80 percent pebbles, 5 percent cobbles and 1 percent stones.

A--0 to 2 inches; yellowish brown (10YR 5/4) extremely gravelly sandy loam, dark yellowish brown (10YR 3/4) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; 65 percent pebbles, 5 percent cobbles and 1 percent stones; neutral (pH 6.8); clear smooth boundary. (1 to 3 inches thick)

Bw--2 to 8 inches; dark yellowish brown (10YR 4/4) very gravelly sandy loam, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and few fine roots; common very fine tubular pores; 50 percent pebbles and 5 percent cobbles; slightly alkaline (pH 7.6); abrupt wavy boundary. (3 to 9 inches thick)

R--8 inches; slightly fractured hard metamorphosed granitic bedrock; common very fine and few fine roots in fractures decreasing with depth.

TYPE LOCATION: Clark County, Nevada; approximately 3 miles east of McCullough Mountain located in the south end and east side of the McCullough Range; about 230 feet south and 1,875 feet west of the projected northeast corner of section 14, T. 27 S., R. 61 E.; USGS Highland Spring, NV 7.5 minute topographic quadrangle; 35 degrees, 36 minutes, 10 seconds north latitude and 115 degrees, 07 minutes, 17 seconds west longitude; UTM 11s, 670168e, 3941518n; 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 - 53 to 58 degrees F.

Depth to lithic contact - 4 to 10 inches.

Control section - Clay content: 10 to 18 percent.

Rock fragments: Averages 35 to 60 percent, mainly fine gravel.

A horizon - Value: 5 or 6 dry, 3 or 4 moist.

Chroma: 3 or 4.

Reaction: Neutral or mildly alkaline.

Bw horizon - Value: 4 through 6 dry, 3 or 4 moist.

Texture: Loam or sandy loam.

Structure: Weak or moderate subangular blocky.

Reaction: Neutral or mildly alkaline.

COMPETING SERIES: This is the Nupper (NV) series. Nupper soils have 60 to 80 percent rick fragments in the control section and is not mainly fine gravel.

GEOGRAPHIC SETTING: Mountmcull soils are on mountains. These soils formed in residuum and colluvium from metamorphosed granitic rock sources. Slope ranges from 30 to 75 percent. Elevations are 3,500 to 6,500 feet. The climate is semiarid with cool, moist winters and warm, intermittently moist summers. Precipitation is greatest in the winter with lesser secondary peak in the summer, typical of the Mojave Desert transitional to Sonoran Desert. The mean annual precipitation is 7 to 9 inches; mean annual temperature is 51 to 56 degrees F., and the frost-free season is 130 to 180 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Nippeno and Nipton series. Nippeno soils have an argillic horizon. Nipton soils have a thermic temperature regime and a typic-aridic moisture regime.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very high runoff; moderately rapid permeability.

USE AND VEGETATION: These soils are used for rangeland and wildlife habitat. The present vegetation is mainly blackbrush, 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, 1994. The name is coined from McCullough Mountain.

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

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

Lithic contact - 8 inches (R layer).

Particle-size control section - 0 to 8 inches (A and Bw horizons).

Responsibility for this series was transferred from Davis to Phoenix 11/2015. The last revision to the series was 7/2006. ET

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National Cooperative Soil Survey
U.S.A.