LOCATION TROUGHSPRING NV

Established Series
Rev: DJM/LJL/ET/TM
12/2015

TROUGHSPRING SERIES

The Troughspring series consists of moderately deep to a hardpan, well drained soils that formed in alluvium derived from limestone. Troughspring soils are on fan remnants. Slope ranges from 4 to 30 percent. The mean annual precipitation is about 15 inches, and the mean annual air temperature is about 48 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, carbonatic, mesic Petrocalcic Paleustolls

TYPICAL PEDON: Troughspring very gravelly silt loam, forest and wildlife habitat. (Colors are for dry soil unless otherwise noted). The soil surface is covered by approximately 40 percent pebbles, 5 percent cobbles and 2 percent stones.

Oi--0 to 2 inches; pinyon-pine duff, slightly decomposed plant material, pine duff. (1/2 to 2 inches thick)

A--2 to 9 inches; dark grayish brown (10YR 4/2) very gravelly silt loam, very dark grayish brown (10YR 3/2) moist; strong medium subangular blocky structure; moderately hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; common fine tubular and very fine and fine interstitial pores; 40 percent pebbles and 3 percent cobbles; (3 percent calcium carbonate equivalent in the fine earth fraction); slightly alkaline (pH 7.6); clear wavy boundary. (5 to 8 inches thick)

Btk--9 to 14inches; brown (10YR 5/3) very gravelly silt loam, brown (10YR 4/3) moist; strong medium angular blocky structure; moderately hard, friable, moderately sticky and moderately plastic; common very fine through coarse roots; common very fine and fine tubular and interstitial pores; 3 percent, faint, dark yellowish brown (10YR 4/4), clay films on all faces of peds; common, distinct, very pale brown (10YR 8/2) calcium carbonate coats on bottom of rock fragments; 52 percent pebbles; strongly effervescent (16 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline, (pH 8.0); clear wavy boundary. (3 to 5 inches thick)

Bk1--14 to 24 inches; pale brown (10YR 6/3) extremely gravelly silt loam, brown (10YR 4/3) moist; moderate medium and coarse subangular blocky structure; moderately hard, friable, moderately sticky and moderately plastic; common very fine, fine and coarse roots; common fine tubular and very fine interstitial pores; 50 percent, distinct, very pale brown (10YR 8/2) calcium carbonate coats on bottom of rock fragments; 55 percent pebbles and 10 percent cobbles; violently effervescent (65 percent calcium carbonate equivalent in the fine earth fraction); moderately alkaline, (pH 7.9); clear wavy boundary. (8 to 14 inches thick)

2Bk2--24 to 29 inches; very pale brown (10YR 8/2) 60 percent moderately cemented petrocalcic horizon; massive; hard, very firm, brittle; 40 percent grayish brown (10YR 5/2) extremely gravelly silt loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure;slightly sticky and slightly plastic; 40 percent pebbles; violently effervescent (40 percent calcium carbonate equivalent); moderately alkaline, (pH 8.0); abrupt irregular boundary. (0 to 6 inches thick)

2Bkm--29 to 63 inches; very pale brown (10YR 8/2) strongly cemented petrocalcic horizon; massive; extremely hard, extremely firm, brittle; discontinuous lamellae cap; 10 percent lenses of weakly cemented calcium carbonate; 50 percent pebbles; violently effervescent (60 percent calcium carbonate equivalent); moderately alkaline, (pH 8.1).

TYPE LOCATION: Clark County, Nevada; On the southwest flank of Willow Peak, approximately 1 mile east of the junction of Wheeler Pass road and the road to Trough Springs; 2150 feet south and 230 feet west of the northeast corner of section 22, T. 18 S., R. 55 E.; USGS Wheeler Well, Nevada 7.5 minute quadrangle; 36 degrees, 22 minutes, 24 seconds north latitude and 115 degrees, 46 minutes, 52 seconds west longitude; UTM 11s, 609338e 4026048n; 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 - 47 to 52 degrees F.

(Depth of the diagnostic horizons is from the mineral soil surface.)

Depth to the base of the mollic epipedon: 8 to 13 inches
Depth to the calcic horizon: 5 to 8 inches.
Depth to the petrocalcic horizon: 20 to 40 inches.

Control section - Clay content: 18 to 27 percent.

Rock fragments: 35 to 70 percent.

Oi horizon Organic matter: 40 to 80 percent.
Bulk density: 0.3 to 0.5.

A horizon - Value: 3 or 4 moist.
Organic matter: 3 to 6 percent.

Btk - horizon Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 2 or 3 dry or moist.
Clay content: 18 to 27 percent
Rock fragments: 35 to 60 percent mainly gravel.
Structure: Subangular or angular blocky.
Consistence: Slightly hard or hard.
Calcium carbonate equivalent in the fine earth fraction: 10 to 25 percent .
Organic matter: 2 to 4 percent.

Bk1 - horizon Value: 5 or 6 dry, 4 or 5 moist
Rock fragments: 40 to 70 percent, mainly gravel,
Structure: Strong and moderate subangular blocky
Consistence: Moderately hard and hard
Calcium carbonate equivalent in the fine earth fraction: 40 to 80 percent .

2Bk2 (when present) and 2Bkm horizons - Consistence: Very hard and hard.
Calcium carbonate equivalent in the fine earth fraction: 50 to 80 percent .
Other features; Moderately through very strongly cemented with some pedons having weakly cemented lenses in the upper portion. Some pedons have 10 to 50 percent discontinuous lenses of very gravelly silt loam in the upper 6 inches of the subhorizon.

COMPETING SERIES: There are no competing series..

GEOGRAPHIC SETTING: Troughspring soils are on fan remnants. Slope ranges from 4 to 30 percent. These soils formed in alluvium derived from limestone. Elevations are 7,000 to 8,700 feet. The climate is sub-humid continental, cool, with moist winters and common summer convection storms.Mean annual precipitation is 14 to 16 inches. The mean annual soil temperature is 45 to 50 degrees F., and the frost free season is 90 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Charkiln, Doespring and Buckspring soils. The Charkiln soils have an argillic horizon with a base below below 40 inches and do not have a petrocalcic horizon. Doespring soils do not have an argillic horizon. Buckspring soils are shallow over limestone bedrock.

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

USE AND VEGETATION: These soils are used for forest and wildlife habitat. Vegetation is mainly singleleaf pinyon, curlleaf mountain mahogany, yellowleaf silktassle, Utah serviceberry and Gambles oak.

DISTRIBUTION AND EXTENT: Mojave Desert of southern Nevada; MLRA 30. These soils are of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA

SERIES ESTABLISHED: Clark County Area, Nevada, 2006. Proposed in Clark County, Nevada, 2005. This series was coined from Trough Springs.

REMARKS:

Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 2 to 14 inches (A and Btk horizons).
Calcic horizon - 9 to 24 inches (Btk and Bk1 horizons).
Petrocalcic horizon - 24 to 63 inches (2Bk2 and 2Bkm horizons).
Particle size control section - 12 to 24 inches (Part of the Btk and Bk1 horizons).

ADDITIONAL DATA: Sampled on October 7, 2004, by NRCS Nevada staff, samples sent to NSSL, Lincoln, NE. Pedon ID is S04NV-003-009.

Responsibility for this series was transferred from Davis to Phoenix 12/2015. The last revision to the series was 7/2006. ET

National Cooperative Soil Survey
U.S.A.