LOCATION VIRGIN PEAK             NV+AZ

Established Series
Rev. ELS/RLB/ET
02/2019

VIRGIN PEAK SERIES

The Virgin Peak series consists of very shallow, well drained soils that formed in material weathered from gneiss and schist. Virgin Peak soils are on mountains. Slope ranges from 30 to 75 percent. The mean annual precipitation is about 16 inches and the mean annual air temperature is about 54 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic, shallow Aridic Haplustolls

TYPICAL PEDON: Virgin Peak very gravelly loam, forest and wildlife habitat. (Colors are for dry soil unless otherwise noted.)

A--0 to 7 inches; brown (10YR 5/3) very gravelly loam, dark brown (10YR 3/3) moist; moderate medium granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and medium roots; many very fine and fine interstitial pores; 50 percent pebbles and 5 percent cobbles; neutral (pH 7.0); abrupt irregular boundary. (6 to 10 inches thick)

Cr--7 to 14 inches; reddish yellow (7.5YR 6/6) weathered gneiss, strong brown (7.5YR 5/6) moist; massive; very hard, very firm; common very fine and few fine roots in fractures; diffuse smooth boundary. (3 to 9 inches thick)

R--14 to 20 inches, light brownish gray (10YR 6/2) extremely hard gneiss.

TYPE LOCATION: Clark County, Nevada, approximately three miles southeast of Keywest Corral on the crest of the Virgin Mountain; about 625 feet north and 670 feet east of the southwest corner of sec.25, T.15S., R.70E.; USGS Whitney Pocket, NV 7.5 minute topographic quadrangle; 36 degrees, 35 minutes, 41.8 seconds north latitude, and 114 degrees, 7 minutes, 38.7 seconds west longitude; UTM 11s, 756971e, 4053782n; NAD 83.

RANGE IN CHARACTERISTICS:

Soil Moisture- usually dry, moist in late winter and early spring and intermittently moist in the upper part following summer convection storms; aridic soil moisture regime bordering on ustic.

Mean annual soil temperature - 53 to 59F.

Depth to paralithic contact - 6 to 10 inches

Depth to bedrock - 13 to 20 inches.

Control section - Clay content: 8 to 18 percent.

Rock fragment: 50 to 75 percent rock fragments. Gravel ranges from 40 to 75 percent and stones and cobbles 0 to 15 percent by volume.

Reaction: Neutral or slightly alkaline

A horizon - Hue: 10YR or 7.5YR,

Value: 4 or 5 dry, 2 or 3 moist

Chroma: 2 or 3.

Texture: Loam or fine sandy loam.

C horizon (when present): Value at least one unit higher dry and moist than the overlying A horizon.

Chroma: 3 through 6.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Virgin Peak soils are on mountain slopes. Elevations are 4,700 to 7,000 feet. Slope ranges from 30 to 75 percent. The soils formed in material weathered from gneiss and schist. The climate is sub-humid continental, with cool, moist winters and common summer convection storms. The mean annual precipitation is 14 to 18 inches, mean annual temperature is 51 to 57F; and the frost-free season is 130 to 180 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pulsipher soils. Pulsipher soils have a lithic contact.

DRAINAGE AND PERMEABILITY: Well drained; very high runoff; moderate permeability.

USE AND VEGETATION: These soils are used for forest and wildlife habitat. The vegetation is principally singleleaf pinyon, mountain big sagebrush, snowberry, Gambels oak, Utah serviceberry, Utah juniper, muttongrass and blue grama.

DISTRIBUTION AND EXTENT: Mojave Desert of southern Nevada and northwestern Arizona; MLRA 30.. These soils are not extensive.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: PHOENIX, ARIZONA

SERIES ESTABLISHED: Clark County (Virgin River Area), Nevada, 1970.

REMARKS: The classification was changed from Lithic Haplustolls to a shallow family of Typic Haplustolls in 1994. The activity class was added to the classification in March of 2003. Competing series were not checked at that time. ET. The classification was updated and changed from Typic Haplustolls to Aridic Haplustolls in 2006. LJL.

Diagnostic horizon and features recognized in this pedon are:

Mollic epipedon 0 to 7 inches (A horizon)

Paralithic contact - 7 inches (Cr layer)

Hard bedrock - 14 inches (R layer)

Particle size control section - 0 to 7 inches (A horizon)

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National Cooperative Soil Survey
U.S.A.