LOCATION MACKSCANYON             NV

Established Series
REV: LJL/ET/TM
11/2015

MACKSCANYON SERIES

The Mackscanyon series consists of very deep,well drained soils that formed in alluvium from limestone and dolostone. Mackscanyon soils are on fan remnants. Slope ranges from 8 to 50 percent. The mean annual precipitation is about 14 inches and the mean annual air temperature is about 47 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, carbonatic, mesic Aridic Calciustolls

TYPICAL PEDON: Mackscanyon very gravelly silt loam - forest and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 55 percent pebbles, 5 percent cobbles and 15 percent pinyon pine needles.

ABk1--0 to 2 inches; brown (10YR 4/3) very gravelly silt loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; common very fine and few fine tubular pores; 20 percent, distinct, yellow brown (dry), calcium carbonate coats on bottom of rock fragments; 35 percent pebbles, 5 percent cobbles and 2 percent stones; violently effervescent (20 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.0); abrupt smooth boundary.

ABk2--2 to 6 inches; brown (10YR 4/3) very gravelly silt loam, dark brown (10YR 3/3) moist; strong medium and coarse subangular blocky structure; moderately hard, very friable, slightly sticky and slightly plastic; common very fine, fine and medium roots; common very fine, fine and medium tubular pores; 90 percent, continuous, prominent, white, irregular, calcium carbonate coats; 40 percent pebbles and 5 percent cobbles; violently effervescent (20 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.2); abrupt wavy boundary. (Combined thickness of the ABk horizons is 6 to 10 inches)

Bkq1--6 to 19 inches; brown (10YR 5/3) very gravelly loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; moderately hard, very friable, slightly sticky and slightly plastic; common very fine through medium, few coarse and very coarse roots; common very fine, few fine and medium tubular pores; 3 percent, less than 1 mm, prominent, very pale brown (10YR 8/2), irregular, calcium carbonate masses in matrix around concentrations; 90 percent, continuous, prominent, calcium carbonate coats on bottoms and sides of rock fragments; 2 percent silica pendants on bottom of rock fragments; 45 percent pebbles (5 percent paragravels) and 5 percent cobbles; violently effervescent (30 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.2); clear smooth boundary.

Bkq2--19 to 30 inches; pale brown (10YR 6/3) very gravelly loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; moderately hard, very friable, slightly sticky and slightly plastic; few very fine and common fine roots; 75 percent, continuous, prominent, white, calcium carbonate coats around rock fragments; 5 percent,0.1 to 1 mm, brown (7.5YR 5/4), silica pendants on bottom of rock fragments; 50 percent discontinuous moderately to very strongly cementation; 55 percent pebbles and 1 percent cobbles; violently effervescent (45 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.2); clear smooth boundary.

Bkq3--30 to 59 inches; light gray (10YR 7/2) extremely gravelly loam, light brownish gray (10YR 6/2) moist; massive; hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; 75 percent, continuous, prominent, white, calcium carbonate coats around rock fragments; 2 percent silica pendants on bottom of rock fragments; 60 percent pebbles; violently effervescent (45 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.2). (Combined thickness of the Bkq horizons is 30 to 60 inches)

TYPE LOCATION: Clark County, Nevada; about 14 miles south of Indian Springs located on the north end of the Spring Mountains; approximately 3 miles south and 3 miles east of the community of Cold Creek; 1,320 feet west and 120 feet north of the southeast corner of section 16, T. 18 S., R. 56 E. USGS Cold Creek, NV 7.5 minute topographic quadrangle; MDBM; 36 degrees, 22 minutes, 41.9 seconds north latitude and 115 degrees, 41 minutes, 23.1 seconds west longitude; USGS Cold Creek, Nevada 7.5 minute quadrangle; UTM 11S, 0617525e 4026704n; NAD83.

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 moisture regime bordering on ustic.

Soil temperature: 47 to 52 degrees F.

Mollic epipedon thickness: 7 to 10 inches, after mixing.

Depth to calcic horizon: 6 to 20 inches.

Control section - Rock fragments: Averages 50 to 65 percent, mainly gravel.
Clay content: 8 to 18 percent.

ABk horizons - Structure: moderate or strong, fine through coarse.
Consistence: Soft or slightly hard, very friable.
Calcium carbonate equivalent of the fine earth fraction: 15 to 25 percent.
Organic matter: 1.0 to 2.5 percent.

Bkq horizons Chroma: 2 through 4.
Texture: Loam or sandy loam.
Structure: Weak or moderate, fine or medium.
Consistence: Slightly hard through very hard, nonplastic and slightly plastic.
Rock fragments: 45 to 70 percent, mainly gravel.
Calcium carbonate equivalent of the fine earth fraction: 25 to 55 percent.

COMPETING SERIES: These are the Cuate and Lapdun series. Cuate soils have a lithic contact at 20 to 40 inches. Lapdun soils formed in volcanic parent material.

GEOGRAPHIC SETTING: Mackscanyon soils are on fan remnants. Slope ranges from 8 to 50 percent. These soils formed in alluvium from limestone and dolostone. Elevations are 5,400 to 8,600 feet. The climate is sub-humid continental, cool, with moist winters and occasional summer convection storms. The mean annual precipitation is 12 to 16 inches; mean annual air temperature is 45 to 50 degrees F., and the frost-free season is 90 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Kylecanyon, Leecanyon and Luckystrike soils. Kylecanyon soils are moderately deep to a petrocalcic horizon. Leecanyon soils do not have a mollic epipedon and are shallow to a petrocalcic horizon. Luckystrike soils have an argillic horizon.

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

USE AND VEGETATION: These soils are used for forest and wildlife habitat. The present vegetation is mainly singleleaf pinyon, Utah juniper, black sagebrush, Stansbury cliffrose, banana yucca, blue grama, muttongrass and green ephedra.

DISTRIBUTION AND EXTENT: Mojave Desert of southern Nevada; MLRA 30. These soils are of moderately 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, 2003. The name is coined from Macks Canyon located in the Spring Mountains.

REMARKS: Diagnostic horizons and features recognized in the profile are:
Mollic epipedon - 0 to 7 inches (ABk1, ABk2, and part of the Bkq1 horizons (after mixing)).
Calcic horizon - 6 to 59 inches (Bkq1, Bkq2 and Bkq3 horizons).
Particle-size control section - 10 to 40 inches (part of the Bkq1, Bkq2 and Bkq3 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.