LOCATION TRUNK                   NV

Established Series
Rev. MJZ/RLB/JBF
03/2016

TRUNK SERIES

The Trunk series consists of moderately deep, well drained soils that formed in residuum and colluvium derived from andesite, rhyolite, quartzite, chert, limestone, sandstone, shale, slate and argillite. The Trunk soils are on convex mountain and foothill crests and side slopes, on side slopes of plateaus and on fan remnants with a rock core. Slopes are 4 to 50 percent. The mean annual precipitation is about 230 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Fine, smectitic, mesic Xeric Haplargids

TYPICAL PEDON: Trunk gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted).

A--0 to 8 cm; light brownish gray (10YR 6/2) gravelly loam, dark grayish brown (10YR 4/2) moist; moderate fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine interstitial pores; 1 percent stones, 2 percent cobbles, and 25 percent gravel; neutral (pH 7.0); clear smooth boundary. (8 to 15 cm thick)

Bt--8 to 30 cm; yellowish brown (10YR 5/4) gravelly clay, dark yellowish brown (10YR 4/4) moist; weak fine prismatic structure parting to strong very fine subangular blocky; very hard, firm, moderately sticky and moderately plastic; common very fine, few fine and medium roots; common very fine and fine tubular pores; many faint and few distinct clay films on peds and lining pores; 15 percent gravel; neutral (pH 7.0); clear wavy boundary. (15 to 30 cm thick)

Btk1--30 to 50 cm; light yellowish brown (10YR 6/4) gravelly clay, yellowish brown (10YR 5/4) moist; moderate fine subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; few very fine and fine roots; common very fine and fine tubular pores; few distinct clay films lining pores; 25 percent gravel; many fine distinct very pale brown (10YR 8/2) soft carbonate masses; violently effervescent; moderately alkaline (pH 8.4); clear wavy boundary. (10 to 30 cm thick)

Btk2--50 to 76 cm; light yellowish brown (10YR 6/4) very gravelly clay loam, yellowish brown (10YR 5/4) moist; moderate fine subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; few very fine roots; common very fine and few fine tubular pores; common distinct clay films lining pores; 35 percent gravel; may fine distinct very pale brown (10YR 8/2) soft carbonate masses; violently effervescent; moderately alkaline (pH 8.4); abrupt irregular boundary. (15 to 30 cm thick)

2R--76 cm; fractured quartzite; weathered pockets can be dug with hand tools; carbonatecoats and clay coats along fractures in bedrock.

TYPE LOCATION: Pershing County, Nevada; approximately 20 miles south of Winnemucca, about 1,000 feet north and 1,000 feet west of the southeast corner of section 11, T. 33 N., R. 38 E.; USGS Clear Creek Ranch 7.5 minute topographic quadrangle; latitude 40 degrees 44 minutes 43 seconds N and longitude 117 degrees 40 minutes 01 second W; WGS84 Decimal Degrees 40.7452778 latitude, -117.6669444 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in the late fall, winter and early spring months, dry late May through October; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 8 to 12 degrees C.
Depth to bedrock: 50 to 100 cm.
Depth to carbonate: 25 to 50 cm.

Particle-size control section - Clay content: 35 to 50 percent.
Rock fragments: 15 to 35 percent, mainly gravel.

A horizon
Value: 5 or 6 dry, 3 through 5 moist.
Chroma: 2 or 3.
Reaction: Neutral through slightly alkaline.

Bt horizons
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 3 through 5.
Texture: Gravelly clay loam or gravelly clay with more than 30 percent sand.
Clay content: 35 to 50 percent.
Rock fragments: 15 to 35 percent, mainly gravel.
Reaction: Neutral through slightly alkaline in noncalcareous upper sub horizon, moderately alkaline or strongly alkaline in calcareous lower subhorizon.
Consistence: Slightly hard to very hard, dry; friable or firm, moist.
Carbonates: Noneffervescent in the upper part; lower part is slightly effervescent through violently effervescent with segregated lime as soft masses, filaments or coatings on rock fragments.

COMPETING SERIES: These are the Buncelvoir, Diaz, Farmell, Glasgow, Lanktree, Milkiway, Oppio, Risley, and Schamp series.

Buncelvoir, Farmell, Lanktree, Milkiway and Schamp soils are very deep. Diaz soils have mildly to moderately alkaline A horizons, argillic horizons of silty clay or clay with less than 30 percent sand and lack rock fragments. Glasgow soils have argillic horizons with less than 15 percent rock fragments. Oppio soils lack secondary lime. Risley soils have less than 15 percent rock fragments in the argillic horizon and have a paralithic contact at a depth of 50 to 100 cm.

GEOGRAPHIC SETTING: Trunk soils are on sideslopes of plateaus and fan piedmonts with a rock core, and convex mountain and foothill crests and side slopes. These soils formed in residuum and colluvium from andesite, rhyolite, quartzite, chert, sandstone, shale, slate and argillite. Slopes are 4 to 50 percent. Elevations are 1,375 to 1,985 meters. The climate is cool, semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 200 to 250 mm; mean annual temperature is 7 to 10 degrees C, and the frost-free season is 100 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Burrita, Golsum and Pocan soils. Burrita soils have a lithic contact within 50 cm and a clayey-skeletal control section. Golsum soils have an average annual soil temperature colder than 7 degrees C. Pocan soils lack bedrock within a depth of 100 cm.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium or rapid runoff; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly Wyoming big sagebrush, bottlebrush squirreltail, rabbitbrush, horsebrush, cheatgrass and ephedra.

DISTRIBUTION AND EXTENT: North-central Nevada. MLRA 24. These soils are moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Pershing County (BLM Sonoma Planning Unit), Nevada. 1974.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon _ The zone from the soil surface to 8 cm (A horizon).
Argillic horizon - The zone from 8 to 76 cm (Bt, Btk1 and Btk2 horizons).
Xeric intergrade - Meets organic carbon requirement for xeric.
Lithic contact - The boundary at 76 cm (2R layer).
Particle-size control section - The zone from 8 to 58 cm (Bt and Btk1 horizons and part of the Btk2 horizon).

---

National Cooperative Soil Survey
U.S.A.