LOCATION TRALEY NVEstablished Series
The Traley series consists of deep, well drained soils that formed in colluvium derived from limestone and dolostone. Traley soils are on mountains. Slope ranges from 30 to 50 percent. The mean annual precipitation is about 15 inches and the mean annual temperature is about 52 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Calcidic Argiustolls
TYPICAL PEDON: Traley very gravelly loam, forest land and wildlife habitat. (Colors are for dry soil unless otherwise noted.) The soil surface is covered by approximately 50 percent pebbles and 2 percent cobbles.
A1--0 to 2 inches; brown (10YR 4/3) very gravelly loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; common very fine and fine tubular pores; 50 percent pebbles and 2 percent cobbles; slightly alkaline (pH 7.6); clear smooth boundary.
A2--2 to 8 inches; brown (10YR 4/3) very gravelly loam, brown (10YR 5/3) moist; strong medium and coarse subangular blocky structure; moderately hard, friable, slightly sticky and slightly plastic; common very fine and fine tubular pores; 45 percent pebbles; slightly alkaline (pH 7.6); clear smooth boundary. (Combined thickness of the A horizons is 7 to 11 inches.)
Btk1--8 to 17 inches; dark yellowish brown (10YR 4/4) gravelly loam, dark yellowish brown (10YR 4/4) moist; strong fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine, fine and medium and few coarse roots; common very fine and few fine tubular pores; common discontinuous distinct colloidal stains on sand grains; many faint clay films lining pores; few fine calcium carbonate coats on bottom of rock fragments; 30 percent pebbles; slightly alkaline (pH 7.4); clear wavy boundary.
Btk2--17 to 27 inches; dark yellowish brown (10YR 4/4) very gravelly loam, dark yellowish brown (10YR 4/4) moist; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine, fine and medium and few coarse roots; common very fine interstitial and few very fine and fine tubular pores; common discontinuous distinct colloidal stains on sand grains; many faint clay films on faces of peds and lining pores; few medium calcium carbonate coats on bottom of rock fragments; 45 percent pebbles; slightly effervescent; slightly alkaline (pH 7.6); clear wavy boundary. (Combined thickness of the Bt horizons is 13 to 22 inches thick)
Bk--27 to 48 inches; very pale brown (10YR 7/3) very gravelly sandy loam, brown (10YR 5/3) moist; massive; hard, firm, slightly sticky and slightly plastic; few very fine, fine and medium roots; common very fine interstitial pores; common calcium carbonate filaments and masses with 5 to 15 percent discontinuous weakly cemented lenses; 45 percent pebbles; violently effervescent; strongly alkaline (pH 8.6); (20 to 27 inches thick)
R--48 inches; hard dolomitic limestone.
TYPE LOCATION: Clark County, Nevada; west of Las Vegas in the Red Rock National Conservation Area, along the dirt road that runs between Lovell Canyon and the sandstone bluffs approximately 1/3 mile east of Red Rock Summit; 450 feet east and 970 feet south of the northwest corner of section 18, T. 21 S., R. 58 E.; USGS La Madre Spring, NV 7.5 minute topographic quadrangle; 36 degrees 7 minutes 43 seconds north latitude and 115 degrees 31 minutes 37 seconds west longitude; UTM 11s, 632551e, 3999218n; 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. The soils have an aridic moisture regime that borders on ustic.
Mean annual soil temperature - 47 to 54 degrees.
Mollic epipedon thickness - 7 to 11 inches.
Depth to calcic horizon: 20 to 33 inches.
Depth to bedrock - 40 to 60 inches.
Control section - Clay content: 18 to 27 percent.
Rock fragments: Averages 35 to 60 percent, mainly gravels.
A horizon - Hue: 10YR or 7.5YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Organic matter content: 1 or 2 percent.
Btk horizons - Hue: 10YR or 7.5YR
Value: 4 or 5, dry or moist
Rock fragments: Averages 35 to 60 percent, ranges from 25 to 60 percent in any one horizon.
Structure: Fine through coarse subangular blocky.
Calcium carbonate equivalent in the fine earth fraction: 1 to 5 percent .
Other features: Noneffervescent in the upper part, very slightly or slightly effervescent in the lower part.
Bk horizon - Value: 6 or 7 dry, 5 or 6 moist.
Chroma: 3 or 4, dry or moist.
Clay content: 8 to 18 percent.
Rock fragments: 35 to 60 percent.
Identifiable secondary carbonates by volume: 5 to 15 percent.
Calcium carbonate equivalent in the fine earth fraction: 5 to 15 percent
COMPETING SERIES: These are the Espadon (NM), Luckystrike (NV) and Resolana (NM) series. Espadon, Luckystrike and Resolana soils do not have a lithic contact between 40 and 60 inches. Additionally, Espadon soils have an ustic soil moisture regime bordering on aridic. Resolana soils have formed in noncalcareous parent material and has an ustic soil moisture regime bordering on aridic.
GEOGRAPHIC SETTING: Traley soils are on mountain. These soils formed in colluvium derived from limestone and dolostone. Slope ranges from 30 to 50 percent. Elevations are 5,000 to 7,300 feet. The climate is sub-humid continental, with cool, moist winters and occasional summer convection storms. The mean annual precipitation is 14 to 16 inches, mean annual temperature is 45 to 53 degrees F., and the frost-free period is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: This is the Seralin soil. Seralin soils are underlain by bedrock at depths of 8 to 14 inches.
DRAINAGE AND PERMEABILITY: Well drained; high runoff; moderate permeability.
USE AND VEGETATION: These soils are used for forest land and wildlife habitat. The present vegetation is mainly singleleaf pinyon, Utah juniper, Gambel's oak, and muttongrass.
DISTRIBUTION AND EXTENT: Mojave Desert of southern Nevada; MLRA 30. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Clark County Area, Nevada, 2006. Proposed in Clark County, Nevada, 1995. The name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 8 inches (A1 and A2 horizons).
Argillic horizon - 8 to 27 inches (Btk1 and Btk2 horizons).
Calcic horizon - 27 to 48 inches (Bk horizon).
Lithic contact - 48 inches (R layer).
Particle-size control section - 8 to 27 inches (Btk1 and Btk2 horizons).