LOCATION HOLLACE                 NV

Established Series
Rev. DJM/RLB/JBF
06/2016

HOLLACE SERIES

The Hollace series consists of shallow to a petrocalcic, well drained soils that formed in residuum and colluvium derived from andesite, ignimbrite, basalt, and volcanic tuffs of intermediate composition. The Hollace soils are on mountain slopes. Slopes are 8 to 30 percent. The mean annual precipitation is about 200 mm and the mean annual temperature is about 12 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic, shallow Ustalfic Petrocalcids

TYPICAL PEDON: Hollace very gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with 10 percent cobbles and 35 percent gravel.

A--0 to 5 cm; grayish brown (10YR 5/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; strong fine granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; many fine and medium interstitial pores; 10 percent cobbles and 35 percent gravel; slightly alkaline (pH 7.8); clear smooth boundary. (5 to 10 cm thick)

Bt--5 to 20 cm; brown (7.5YR 5/4) very cobbly clay loam, dark brown (7.5YR 3/4) moist; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common fine and medium tubular pores; common faint clay films lining pores; 30 percent cobbles and 15 percent gravel; slightly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (8 to 20 cm thick)

Btk1--20 to 36 cm; light brown (7.5YR 6/4) very cobbly clay loam, brown (7.5YR 4/4) moist; strong medium subangular blocky structure; hard, firm, very sticky and very plastic; few very fine and fine and few medium roots; common very fine and fine tubular pores; common faint clay films lining pores and common pressure faces; many thin carbonate coats and pendants on vertical and undersides of rock fragments; 30 percent cobbles and 15 percent gravel; strongly effervescent; moderately alkaline (pH 8.0); gradual smooth boundary. (15 to 25 cm thick)

Btk2--36 to 43 cm; light brown (7.5YR 6/4) very cobbly clay loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; hard, firm, very sticky and very plastic; few very fine and fine and common medium roots; common very fine and fine tubular pores; common faint clay films lining pores and common pressure faces; many moderately thick carbonate coats on vertical and undersides of rock fragments; 30 percent cobbles and 15 percent gravel; violently effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (8 to 13 cm thick)

Bkqm--43 to 53 cm; very pale brown (10YR 8/2) indurated petrocalcic horizon, very pale brown (10YR 7/3) moist; massive; extremely hard; violently effervescent. (8 to 13 cm thick)

R--53 cm; andesitic bedrock.

TYPE LOCATION: Lincoln County, Nevada; in the southern Delamar Mountains; approximately 1000 feet east and 2275 feet north of the projected southwest corner of section 7, T. 9 S., R. 64 E.; USGS Delamar 3 NE 7.5 minute topographic quadrangle; latitude 37 degrees 10 minutes 48 seconds N and longitude 114 degrees 51 minutes 57 seconds W; WGS84 Decimal Degrees 37.1800000 latitude, -114.8658333 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist in late summer and for short periods in winter and spring; aridic soil moisture regime bordering in ustic.
Mean annual soil temperature: 11 to 14 degrees C.
Depth to petrocalcic horizon: 36 to 50 cm.
Depth to bedrock: 46 to 64 cm.
Reaction: Slightly alkaline or moderately alkaline.

Particle-size control section - Clay content: Averages 22 to 33 percent.
Rock fragments: 35 to 55 percent, predominantly cobbles.

A horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3.
Carbonates: Noneffervescent or slightly effervescent.

Bt horizon
Hue: 7.5YR or 5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 through 4.
Clay content: 18 to 30 percent.
Texture: Loam or clay loam.

Btk horizons
Hue: 7.5YR or 5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 through 4.
Texture: Clay loam or sandy clay loam.
Clay content: 27 to 35 percent.
Carbonates: Strongly effervescent or violently effervescent.
Other features: This horizon commonly has fractured petrocalcic material in the lower part.

Bkqm horizon
Silica: 10 percent discontinuous accessory silica lenses throughout.

COMPETING SERIES: This is the Plaintank series.

The Plaintank soils have gravelly alluvium underlying the petrocalcic horizon.

GEOGRAPHIC SETTING: Hollace soils are on mountain slopes. The soils formed in residuum and colluvium derived from andesite, ignimbrite, basalt, and volcanic tuffs of intermediate composition. Slopes are 8 to 30 percent. Elevations are 1,280 to 1,710 meters. The mean annual precipitation is 200 to 250 mm, the mean annual temperature is 11 to 14 degrees C, and the frost-free season is about 160 to 210 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gabbvally, Kanesprings, and Wyva series. Gabbvally soils lack a petrocalcic horizon. Kanesprings soils have mean annual soil temperatures warmer than 15 degrees C and lack a petrocalcic horizon. Wyva soils lack a petrocalcic horizon.

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

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly blackbrush, green ephedra, desert bitterbrush, desert needlegrass, and galleta.

DISTRIBUTION AND EXTENT: Southern Nevada. These soils are not extensive. MLRA 29.

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

SERIES ESTABLISHED: Lincoln County, Nevada, South Part, 1992.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 5 om (A horizon).
Argillic horizon - The zone from 5 to 43 cm (Bt, Btk1, and Btk2 horizons).
Ustic Features - Meets soil moisture regime and organic carbon requirement for ustic.
Petrocalcic horizon - The zone from 43 to 53 cm (Bkqm horizon).
Lithic contact - The boundary at 53 cm (R layer).
Particle-size control section - The zone from 5 to 43 cm (Bt, Btk1, and Btk2 horizons).

---

National Cooperative Soil Survey
U.S.A.