LOCATION SHAGNASTY               NV

Established Series
Rev: WED/RAF/GJS
03/2016

SHAGNASTY SERIES

The Shagnasty series consists of deep or very deep, well drained soils that formed in residuum and colluvium derived from rhyolite, andesite, and quartzite. Shagnasty soils are on mountain side slopes. Slopes are 15 to 50 percent. The mean annual precipitation is about 360 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Typic Argixerolls

TYPICAL PEDON: Shagnasty stony loam--woodland. (Colors are for dry soil unless otherwise noted.) The soil surface is partly covered with 15 percent stones, 5 percent cobbles, and 5 percent gravel.

A--0 to 23 cm; grayish brown (10YR 5/2) stony loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine through coarse roots; common fine and medium tubular, common fine interstitial pores; 10 percent gravel, 5 percent cobbles and 15 percent stones; slightly acid (pH 6.2); clear smooth boundary. (8 to 30 cm thick)

Bt--23 to 30 cm; dark grayish brown (10YR 4/2) cobbly loam, dark brown (10YR 3/3) moist; moderate fine angular blocky structure; hard, firm, moderately sticky and moderately plastic; many very fine through coarse roots; common fine and medium tubular, common fine interstitial pores; many distinct clay films on peds and lining pores; 10 percent gravel and 20 percent cobbles; slightly acid (pH 6.2); abrupt smooth boundary. (8 to 18 cm thick)

2Bt1--30 to 58 cm; light yellowish brown (10YR 6/4) clay, dark yellowish brown (10YR 4/4) moist; strong medium and coarse prismatic structure; extremely hard, very firm, very sticky and very plastic; common medium and few fine roots; few fine tubular pores; continuous prominent pressure faces on peds; 5 percent cobbles; slightly acid (pH 6.2); gradual smooth boundary. (18 to 36 cm thick)

2Bt2--58 to 91 cm; light yellowish brown (10YR 6/4) clay, dark yellowish brown (10YR 4/6) moist; strong medium and coarse prismatic structure; extremely hard, very firm, very sticky and very plastic; common medium and few fine roots; few fine tubular pores; continuous prominent pressure faces on peds; 5 percent cobbles; slightly acid (pH 6.2); abrupt smooth boundary. (13 to 33 cm thick)

3Bt1--91 to 109 cm; light yellowish brown (10YR 6/4) cobbly silty clay loam, dark yellowish brown (10YR 4/4) moist; weak medium prismatic structure; very hard, firm, moderately sticky and moderately plastic; common medium and coarse and few fine roots; common fine tubular pores; continuous prominent clay films on peds; 5 percent gravel and 15 percent cobbles; slightly acid (pH 6.4); clear irregular boundary. (15 to 50 cm thick)

3Bt2--109 to 150 cm; yellowish brown (10YR 5/4) cobbly silty clay loam, dark yellowish brown (10YR 4/4) moist; weak, medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common medium and coarse, few fine roots; common fine and medium tubular pores; many distinct clay films on peds and lining pores; 5 percent gravel and 15 percent cobbles; slightly acid (pH 6.2); clear wavy boundary. (30 to 40 cm thick)

3Cr--150 cm; weathered bedrock.

TYPE LOCATION: Lander County, Nevada; approximately 34 miles northwest of Eureka in the Simpson Park Mountains; about 850 feet east and 900 feet north of the southwest corner of section 3, T. 20 N., R. 47 E.; USGS Ackerman Canyon 7.5 minute topographic quadrangle; latitude 39 degrees 37 minutes 22 seconds N and longitude 116 degrees 40 minutes 24 seconds W;WGS84 Decimal Degrees 39.6227778 latitude, -116.6733333 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Moist in winter through early summer, dry mid-July to October; xeric soil moisture regime.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 25 to 40 cm, includes upper part of argillic horizon.
Depth to base of Bt horizon: 100 to more than 150 cm.
Depth to weathered bedrock: 127 to 200 cm.
Reaction: Slightly acid through slightly alkaline.
Other features: Some pedons have secondary carbonates below 100 cm. Some pedons lack lithological discontinuity.

Particle-size control section - Clay content: 35 to 50 percent.
Rock fragments: Average 5 to 15 percent.

A horizon
Value: 4 to 5 dry, 2 or 3 moist.
Chroma: 2 or 3.

Bt horizon
Hue: 7.5YR or 10YR.
Value: 4 through 6 dry, 3 through 5 moist.
Chroma: 3 or 4 in upper part, 4 to 6 in lower part.
Structure: Prismatic or angular blocky or is massive in the lower subhorizons of some pedons.

COMPETING SERIES: These are the Beefhollow, Booford, Harter, Marsden, Observation, Ostler, Rob Roy and Tatouche series.

Beefhollow soils have more than 400 mm of precipitation with significant summer moisture. Booford, Observation and Rob Roy soils have bedrock at a depth of 50 to 100 cm. Harter soils average more than 15 percent rock fragments in the particle-size control section. Leftfork soils formed in limestone. Manila soils are deeper than 200 cm. Marsden soils were formed in lakelaid sediments. Ostler soils lack a discontinuity and are dry for 50 to 70 consecutive days during the summer.

GEOGRAPHIC SETTING: Shagnasty soils are on mountain side slopes. These soils formed in residuum and colluvium derived from rhyolite, andesite and quartzite. Slopes are 15 to 50 percent. Elevations are 1,830 to 2,595 meters. The climate is cool, semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 300 to 400 mm; mean annual temperature is 6 to 7 degrees C, and the frost-free season is 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ravenswood, Segura, Softscrabble, Welch and the competing Walti soils. Ravenswood soils have clayey-skeletal particle-size control section. Segura soils have a lithic contact within a depth of 50 cm. Softscrabble and Welch have less than 35 percent clay in the particle-size control section.

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

USE AND VEGETATION: Woodland, rangeland and wildlife habitat. The vegetation is mainly singleleaf pinyon, Utah juniper and some mountain mahogany with an understory of mountain big sagebrush and Douglas rabbitbrush.

DISTRIBUTION AND EXTENT: North-central Nevada. These soils are moderately extensive. MLRA 24, 28B.

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

SERIES ESTABLISHED: Eureka County, Nevada, 1983.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to about 30 cm (A and Bt horizons).
Argillic horizon - The zone from 23 to 150 cm (Bt, 2Bt1, 2Bt2, 3Bt1 and 3Bt2 horizons).
Paralithic contact - The boundary at 150 cm (Cr layer).
Particle-size control section - The zone from 23 to 73 cm (Bt and 2Bt1 and part of the 2Bt2 horizons).

---

National Cooperative Soil Survey
U.S.A.