LOCATION ESMOD                   NV

Established Series
Rev. SES/JBF/TM-JVC
12/2019

ESMOD SERIES

The Esmod series consists of shallow to duripan, well drained soils that formed in alluvium derived from volcanic rocks with eolian surficial additions of volcanic ash. Esmod soils are on fan remnants. Slopes are 2 to 15 percent. The mean annual precipitation is about 280 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Clayey, smectitic, mesic, shallow Abruptic Xeric Argidurids

TYPICAL PEDON: Esmod very gravelly ashy fine sandy loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with approximately 50 percent gravel.

A1--0 to 5 cm; light brownish gray (10YR 6/2) very gravelly ashy fine sandy loam, very dark grayish brown (10YR 3/2) moist; strong medium and thick platy structure; hard, very friable, nonsticky and nonplastic; many very fine roots; many very fine and fine vesicular pores; 50 percent gravel; neutral (pH 7.0); abrupt wavy boundary. (3 to 8 cm thick)

A2--5 to 15 cm; pale brown (10YR 6/3) gravelly ashy sandy loam, dark brown (10YR 3/3) moist; strong very thin and thin platy structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium and coarse roots; many very fine vesicular and interstitial pores; 30 percent gravel; neutral (pH 7.2); abrupt wavy boundary. (8 to 15 cm thick)

Bt--15 to 38 cm; light brown (7.5YR 6/4) gravelly clay, brown (7.5YR 5/4) moist; strong fine and medium subangular blocky structure; very hard, very friable, very sticky and very plastic; common very fine, few fine and medium roots; common fine tubular pores; common faint and distinct clay films on faces of peds and lining pores; 15 percent gravel; slightly alkaline (pH 7.8); abrupt wavy boundary. (15 to 30 cm thick)

Bqm--38 to 53 cm; pink (7.5YR 8/4) cemented material, strong brown (7.5YR 5/6) moist; strong medium and thick platy structure; extremely hard, extremely firm; strongly cemented by silica; common very fine roots matted on plate surfaces; alternate horizontal light brown (7.5YR 6/4) 1 to 2 mm thick silica laminae on tops of plates, brown (7.5YR 4/4) moist; moderately alkaline (pH 8.0); clear smooth boundary. (10 to 30 cm thick)

Bqkm1--53 to 71 cm; pink (7.5YR 8/4) cemented material, strong brown (7.5YR 5/6) moist; moderate thick and very thick platy structure; extremely hard, extremely firm; continuous and strongly cemented by silica and carbonates; many fine and medium horizontal masses of secondary carbonates; many less than 0.5 mm carbonate and silica coats on bottoms of rock fragments; violently effervescent; moderately alkaline (pH 8.0); clear wavy boundary. (15 to 36 cm thick)

Bqkm2--71 to 91 cm; very pale brown (10YR 7/4) cemented material, dark yellowish brown (10YR 4/6) moist; weak medium and thick platy structure; very hard, extremely firm and very firm; strongly and weakly cemented by silica and carbonates; alternate horizontal discontinuous 0.5 to 2 mm silica laminae; common fine and medium horizontal masses of secondary carbonates; strongly effervescent; moderately alkaline (pH 8.0). (20 to 48 cm thick)

Bqkm3--91 to 152 cm; very pale brown (10YR 8/3) cemented material, brown (7.5YR 5/4) moist; massive; very hard, very firm; weakly and strongly cemented by silica and carbonates; common less than 0.5 mm discontinuous silica laminae; many 1 to 5 mm horizontal masses of secondary carbonates; moderately alkaline (pH 8.0).

TYPE LOCATION: Washoe County, Nevada; south of Bitner Table about 2 miles west of the Sheldon National Wildlife Refuge boundary; about 2,00 feet south and 200 feet east of the northwest corner section 23, T. 43 N., R. 22 E.; USGS Badger Mountain NW 7.5 minute topographic quadrangle; 41 degrees 38 minutes 2.6 seconds north latitude and 119 degrees 28 minutes 47.7 seconds west longitude; WGS84 Decimal Degrees 41.6340556 latitude, -119.4790833 longitude.
RANGE IN CHARACTERISTICS:
Soil moisture: Moist in winter and spring, dry mid-June through October; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Depth to duripan:36 to 50 cm.
Abrupt textural change: An abrupt horizon boundary is normally present between the A2 horizon and the Bt horizon accompanied by an increase in clay content of more than 20 percent.

Particle-size control section - Clay content: 40 to 50 percent.
Rock fragments: 9 to 19 percent, mainly gravel. Lithology of fragments is volcanic rocks such as basalt and tuff.

A horizons
Value: 5 through 7 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Clay content: 10 to 18 percent.
Reaction: Neutral or slightly alkaline.
Volcanic glass content: 30 to 60 percent in coarse silt through fine sand fractions.

Bt horizon
Hue: 5YR through 10YR.
Value: 4 through 6 dry, 3 through 5 moist.
Chroma: 3 through 6, dry or moist.
Texture: Clay or gravelly clay.
Clay content: 40 to 50 percent.
Rock fragments: 9 to 19 percent.
Structure: Subangular blocky, angular blocky, or prismatic parting to subangular or angular blocky.
Reaction: Neutral or slightly alkaline.

Bqm and Bqkm horizons
Hue: 7.5YR or 10YR.
Value: 6 through 8 dry, 4 or 5 moist.
Chroma: 4 through 6, dry or moist.

COMPETING SERIES: These are the Antholop, Fulstone, Grassycan, Kunaton, Puls, Riddenbaugh, and Rogerson series.

Antholop soils are moderately alkaline or strongly alkaline in the Bt horizons and are moist for 10 to 20 days between July and October. Fulstone soils have very strongly cemented or indurated duripans. Grassycan, Kunaton, and Puls soils have a duripan over bedrock that is within 100 cm. Riddenbaugh soils have moderately alkaline Bt horizons and Bk horizons immediately above the duripan. Rogerson soils have a duripan that is less than 100 cm thick.

GEOGRAPHIC SETTING: Esmod soils are on fan remnants. These soils formed in alluvium derived from volcanic rocks with eolian surficial additions of volcanic ash. Slopes are 2 to 15 percent. Elevations range from 1,670 to 1,985 meters. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 250 to 300 mm, the mean annual temperature is 7 to 8 degrees C, and the frost-free period is 80 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: This is the Powlow soil. Powlow soils have Mollic epipedons and are on adjacent slope positions.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high surface runoff; low saturated hydraulic conductivity.

USE AND VEGETATION: Esmod soils are used for rangeland and wildlife habitat. The present vegetation is mainly low sagebrush, bluegrass, and Thurber's needlegrass.

DISTRIBUTION AND EXTENT: Northwestern Nevada. These soils are moderately extensive. MLRA 23.

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

SERIES ESTABLISHED: Washoe County, Nevada (North Part), 1995. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 15 cm (A1 and A2 horizons).
Abrupt textural change and abruptic subgroup feature - The abrupt clay increase of more than 20 percent at 15 cm (between the A2 and Bt horizons).
Argillic horizon - The zone from 15 to 38 cm (Bt horizon).
Identifiable secondary carbonates - The zone from 53 to 152 cm (Bqkm1, Bqkm2, and Bqkm3 horizons).
Duripan - The zone from 38 to 152 cm (Bqm, Bqkm1, Bqkm2, and Bqkm3 horizons).

IParticle-size control section - The zone from 15 to 38 cm (Bt horizon).

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National Cooperative Soil Survey
U.S.A.