LOCATION JUMBOPEAK               NV

Established Series
Rev. LJL/TM/ET
09/2015

JUMBOPEAK SERIES

The Jumbopeak series consists of moderately deep, well drained soils that formed in residuum and colluvium from granite, gneiss and schist. Jumbopeak soils are on mountains. Slope ranges from 30 to 75 percent. The mean annual precipitation is about 11 inches and the mean annual air temperature is about 53 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Aridic Argiustolls

TYPICAL PEDON: Jumbopeak extremely gravelly loamy coarse sand, forest and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 60 percent gravel, 15 percent cobbles, 2 percent stones and 2 percent boulders.

A1--0 to 2 inches; brown (10YR 4/3) extremely gravelly loamy coarse sand, very dark brown (10YR 2/2) moist; weak fine subangular blocky structure parting to moderate very fine granular; soft, very friable, nonsticky and nonplastic; many very fine and few fine roots; many very fine interstitial pores; 50 percent pebbles, 10 percent cobbles, 1 percent stones and boulders; slightly acid (pH 6.5); abrupt wavy boundary. (1 to 2 inches thick)

A2--2 to 9 inches; brown (10YR 4/3) very gravelly coarse sandy loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; many very fine, common fine and few medium roots; many very fine interstitial pores and common very fine and fine tubular pores; 40 percent pebbles and 5 percent cobbles; neutral (pH 7.0); clear wavy boundary. (6 to 12 inches thick)

Bt1--9 to 17 inches; yellowish brown (10YR 5/4) very gravelly coarse sandy loam, dark yellowish brown (10YR 3/4) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and moderately plastic; common very fine through very coarse roots; common very fine and fine tubular pores; 60 percent discontinuous, distinct clay films bridging sand grains and lining pores; 10 percent patchy, distinct clay films on ped faces; 35 percent pebbles, 10 percent paragravel and 15 percent paracobbles; neutral (pH 7.0); clear wavy boundary. (6 to 20 inches thick)

Bt2--17 to 29 inches; yellowish brown (10YR 5/4) very gravelly sandy loam, dark yellowish brown (10YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine through very coarse roots; common very fine and fine tubular pores; 10 percent patchy, faint clay films bridging sand grains and coating rock fragments; 35 percent pebbles, 20 percent paragravel and 20 percent paracobbles; slightly acid (pH 6.5); clear wavy boundary. (4 to 12 inches thick)

Cr--29 to 31 inches; moderately weathered gneiss and schist; moderately difficult to dig with shovel.

TYPE LOCATION: Clark County, Nevada; about 38 miles south and 5 miles east of Mesquite, Nevada; approximately 3/4 miles south and 1/4 mile east of Mica Peak in the Gold Butte area; 225 feet south and 750 feet east of the northwest corner of section 26, T. 19 S., R. 70 E.; USGS Gold Butte, NV 7.5 minute topographic quadrangle; 36 degrees, 15 minutes, 34.1 seconds north latitude and 114 degrees, 09 minutes, 07.9 seconds west longitude; UTM 11, 0755855e 4016492n; 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 thunderstorms; aridic soil moisture regime bordering on ustic.

Soil temperature: 55 to 58 degrees F.

Depth to paralithic contact: 20 to 40 inches.

Organic matter: 1 to 2 percent in the mollic epipedon.

Control section - Clay content: 12 to 18 percent.
Rock fragments: 35 to 60 percent gravel with strongly cemented to indurated cementation class. Rock fragments may range up to 75 percent when including paragravels and parcobbles.

A1 horizon - Hue: 10YR or 7.5YR.
Value: 3, 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3 dry or moist.
Texture: Loamy coarse sand or loamy sand.
Structure: Weak or moderate, fine or medium.
Rock fragments: 60 to 75 percent.
Reaction: Slightly acid or neutral.

A2 horizon - Hue: 10YR or 7.5YR
Value: 4 or 5 dry.
Clay content: 6 to 12 percent.
Texture: Coarse sandy loam or sandy loam.
Structure: Fine or medium.
Consistence: Soft through moderately hard, dry; very friable or friable, moist; nonsticky or slightly sticky, wet.
Rock fragments: 35 to 60 percent.
Reaction: Neutral or slightly alkaline.

Bt1 horizon - Hue: 10YR or 7.5YR
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 3, 4 or 6 dry and moist.
Clay content: 12 to 18 percent.
Texture: Coarse sandy loam or sandy loam.
Structure: Moderate or strong, fine through very coarse.
Consistence: Slightly hard to hard, dry; very friable or friable, moist; slightly plastic and moderately plastic, wet.
Rock fragments: 35 to 60 percent, with 10 to 15 percent pararock fragments.

Bt2 and Btk horizons (when present) - Hue: 10YR or 7.5YR
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 4 or 6.
Clay content: 6 to 12 percent.
Texture: Coarse sandy loam or sandy loam.
Structure: Fine or medium, subangular blocky or massive.
Consistence: Soft or slighlty hard, dry; nonsticky or slightly sticky, nonplastic or slightly plastic, wet.
Rock fragments: 35 to 60 percent gravel with strongly cemented to indurated cementation class. Rock fragments may range up to 75 percent when including paragravels and parcobbles.
Effervescence: Non-effervescent matrix
Reaction: Slightly acid or neutral.
Calcium carbonate equivalent of the fine earth: 0 to 1 percent.
Other features: Some pedons have few thin calcium carbonate coats on rock fragments and ped faces.

Cr or Crt horizon - Other features: Some pedons have clay films on rock fragments or in fractures.

COMPETING SERIES: These are the Golondrina, Irock, Lantis, Majada, Mokiak, Montoso, Murdo, Nederland, Purcella, Romine, Salas, Wandurn, Wheelerwell and Willowman series. Golondrina, Lantis, Majada, Montoso, Murdo, Nederland, Purcella, Romine, and Willowman soils are very deep. Irock soils have C horizons with 5 to 15 percent calcium carbonate equivalent. Mokiak soils have a mean annual soil temperature of 50 to 54 degrees F and sandy clay loam soil textures in the argillic horizon. Salas soils have 25 to 35 percent clay. Wandurn soils are deep to hard bedrock and have mean annual soil temperatures of 49 to 52 degrees. Wheelerwell soils have a mean annual soil temperature of 47 to 52 degrees F.

GEOGRAPHIC SETTING: Jumbopeak soils are on mountains. Slope ranges from 30 to 75 percent. These soils formed in residuum and colluvium from granite, gneiss and schist. Elevations are 3,950 to 6,200 feet. The climate is warm and arid with cool, moist winters and warm, dry summers. The mean annual precipitation is 10 to 12 inches; mean annual air temperature is 51 to 55 degrees F., and the frost-free season is 140 to 180 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Goldbutte and Nolena soils. Goldbutte and Nolena soils are very shallow to bedrock and do not have a mollic epipedon or an argillic horizon.

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

USE AND VEGETATION: These soils are used for forest and wildlife habitat. The present vegetation is mainly pinyon, juniper, turbinella oak, green ephedra, desert needlegrass, arid needlegrass, muttongrass, galleta and Joshua tree.

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, Clark County Soil Survey Area, 2002. The name is coined from Jumbo Peak. Jumbo Peak is located four miles south and 2.5 miles west of this soil type location.

REMARKS: Diagnostic horizons and features recognized in the profile are:
Mollic epipedon - 0 to 9 inches (A1 and A2 horizons).
Argillic horizon - 9 to 17 inches (Bt1 horizon).
Paralithic contact - 29 inches (Cr horizon)
Particle-size control section - 9 to 17 inches (Bt1 horizon).

Responsibility for this series was transferred from Davis to Phoenix 9/2015. The last revision to the series was 7/2006. ET

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National Cooperative Soil Survey
U.S.A.