LOCATION THESISTERS              NV

Established Series
REV: LJL/TM/ET
12/2015

THESISTERS SERIES

The Thesisters series consists of very shallow and shallow, somewhat excessively drained soils that formed in residuum and colluvium from limestone and dolomite. Thesisters soils are on south facing back slopes of mountains. Slope ranges from 30 to 75 percent. The mean annual precipitation is about 16 inches and the mean annual air temperature is about 42 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, carbonatic, frigid Aridic Lithic Haplustolls

TYPICAL PEDON: Thesisters extremely gravelly silt loam, forest and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 80 percent gravel and 3 percent cobbles.

A--0 to 1 inches, (0 to 3 cm); brown (10YR 5/3) extremely gravelly silt loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; moderately hard, very friable, slightly sticky and slightly plastic; common very fine roots throughout; common fine tubular and few medium tubular and many very fine tubular pores; 75 percent pebbles and 3 percent cobbles; strongly effervescence (20 percent calcium carbonate equivalence in the fine earth fraction); moderately alkaline (pH 8.0); abrupt smooth boundary. (1 to 2 inches thick)

Bk--1 to 6 inches, (3 to 15 cm); brown (10YR 4/3) very gravelly silt loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; moderately hard, very friable, slightly sticky and slightly plastic; few fine to coarse roots throughout and many very fine roots throughout; common fine tubular and many very fine tubular pores; 10 percent distinct very pale brown (10YR 8/2) calcium carbonate coats on bottoms of rock fragments and 35 percent distinct very dark brown (10YR 2/2) organic stains on rock fragments; 25 percent distinct light yellowish brown (10YR 6/4) coats of oxidized iron around rock fragments; 50 percent pebbles and 1 percent cobbles; slightly effervescence (80 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline (pH 8.0); very abrupt wavy boundary. (3 to 18 inches thick)

R--6 to 10 inches, (15 to 25 cm); gray (10YR 6/1) limestone bedrock, dark gray (10YR 4/1) moist; common very fine and fine roots in cracks and common medium roots in cracks; slightly effervescence.

TYPE LOCATION: Clark County, Nevada; about 9.7 miles north and 31.5 miles west of Las Vegas, Nevada; approximately 3.1 miles north of Charleston Peak, located in Scout Canyon off of Lee Canyon in the Spring Mountians; sectionalized area 200 feet south and 600 feet west of the northeast corner of section 9, T. 19 S., R. 56 E.; USGS Charleston Peak, Nevada 7.5 minute quadrangle; 36 degrees, 19 minutes, 03.4 seconds north latitude and 115 degrees, 41 minutes, 49.7 seconds west longitude; UTM 11, 616956e 4019963n; NAD83.

RANGE IN CHARACTERISTICS:

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

Soil temperature: 42 to 47 degrees F.

Depth to lithic contact: 4 to 20 inches.

Control section - Rock fragments: averages 35 to 70 percent, mainly gravel.
Clay content: 12 to 20 percent.
Calcium carbonateequivalenct of the less than 20 millimeter fraction: Averages 40 to 80 percent.

A horizon - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 1 through 3.
Clay content: 7 to 15 percent.
Structure: Weak or moderate.
Consistence: Soft through moderately hard, nonsticky or slightly sticky and nonplastic or slightly plastic.
Organic matter: 2 to 5 percent.
Effervescence: Strongly effervescent or violently effervescent.
Reaction: Slightly alkaline or moderately alkaline.
Calcium carbonate equivalent in the fine earth fraction: 10 to 30 percent.

Bk horizon - Value: 2 or 4 dry, 2 or 3 moist.
Chroma: 1 through 3.
Texture: Silt loam or loam.
Structure: Weak through strong, fine or medium.
Consistence: Soft through moderately hard, nonsticky or slightly sticky and nonplastic or slightly plastic.
Rock fragments: 35 to 70 percent, mainly gravel.
Organic matter: 1.0 to 2.0 percent.
Effervescence: Slightly effervescent or strongly effervescent.
Reaction: Slightly alkaline or moderately alkaline.
Calcium carbonate equivalent in the fine earth fraction: 60 to 80 percent.

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: Thesisters soils are on south facing back slopes of mountains. Slope ranges from 30 to 75 percent. These soils formed in residuum and colluvium from limestone and dolomite. Elevations are 8,000 to 11,000 feet. The climate is sub-humid continental, cool, with moist winters and common summer convection storms. The mean annual precipitation is 14 to 18 inches; mean annual air temperature is 40 to 45 degrees F., and the frost-free season is 50 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Maryjane and Mountmummy soils. Maryjane and Mountmummy soils have a very deep and moderately deep soil depth, respectively.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very high runoff; moderate permeability over very slow bedrock.

USE AND VEGETATION: These soils are used for forest and wildlife habitat. The present vegetation is mainly ponderosa pine, white fir, bristlecone pine, limber pine, curleaf mountainmohogany, muttongrass and currant.

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, 2004. The name is coined from The Sisters mountain located 0.9 miles north and 0.7 miles east, in the Spring Mountains.

REMARKS: Diagnostic horizons and features recognized in the profile are:
Mollic epipedon - 0 to 6 inches (A and Bk horizons).
Lithic contact - 6 inches (R layer).
Particle-size control section - 0 to 6 inches (A and Bk horizons).

ADDITIONAL DATA: Sampled on October 6, 2004, by NRCS Nevada staff, samples sent to NSSL, Lincoln, NE. Pedon ID is S04NV-003-011.

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.