LOCATION CHAD                    NV

Established Series
Rev: OAC/RAF/GJS/JBF
01/2023

CHAD SERIES

The Chad series consist of deep, well drained, soils on mountain side slopes. These soils formed in residuum derived from chert and shale with small components of loess and volcanic ash. 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, mixed, superactive, frigid Aridic Argixerolls

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

A1--0 to 10 cm; grayish brown (10YR 5/2) cobbly loam, dark brown (10YR 3/3) moist; moderate very fine granular structure; soft, very friable, nonsticky and slightly plastic; many fine and very fine roots; many fine and very fine interstitial pores; 10 percent gravel and 10 percent cobbles; neutral (pH 7.2); clear smooth boundary. (10 to 15 cm thick)

A2--10 to 25 cm; brown (10YR 4/3) gravelly loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium, common fine and very fine roots; many fine and very fine interstitial pores; 15 percent gravel; neutral (pH 7.2); gradual smooth boundary. (10 to 18 cm thick)

BA--25 to 43 cm; yellowish brown (10YR 5/4) gravelly loam, brown (10YR 4/3) moist; moderate fine angular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; few medium, common fine roots; common fine and very fine tubular pores; few faint clay films in pores and on peds; 20 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary. (8 to 25 cm thick)

Bt1--43 to 71 cm; yellowish brown (10YR 5/4) gravelly clay, dark yellowish brown (10YR 4/4) moist; weak medium prismatic structure parting to moderate medium angular blocky; hard, firm, moderately sticky and moderately plastic; very few fine roots; common fine and very fine tubular pores; many prominent pressure faces on peds; 20 percent gravel; slightly alkaline (pH 7.6); clear wavy boundary. (28 to 40 cm thick)

Bt2--71 to 107 cm; yellowish brown (10YR 5/4) gravelly clay loam, dark yellowish brown (10YR 4/4) moist; moderate medium and fine angular blocky structure; very hard, very firm, moderately sticky and moderately plastic; common fine tubular pores; many prominent pressure faces on peds; 30 percent gravel; slightly alkaline (pH 7.6); abrupt wavy boundary. (30 to 38 cm thick)

Cr--107 cm; shale.

TYPE LOCATION: Eureka County, Nevada; approximately 34 miles northwest of Eureka in the Roberts Mountains; about 1,500 feet north and 1,000 feet east of the southwest corner of Section 24, T.23 N., R.49 E.; latitude 39 degrees 50 seconds 33 seconds N and longitude 116 degrees 25 minutes 4 seconds W; WGS84 Decimal Degrees 39.8425000 latitude, -116.4177778 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture; Moist in winter and spring, continuously dry in all parts for significant periods in summer and fall; xeric soil moisture regime bordering on aridic.
Mean annual soil temperature: 6 to 7 degrees C.
Mollic epipedon thickness: 25 to 38 cm, includes upper part of argillic in some pedons.
Thickness of A and Bt horizon: 100 to 132 cm.
Depth to bedrock: 100 to 150 cm.

Particle-size control section - Clay content: Mixed upper part of argillic is 35 to 45 percent clay.
Rock fragments: 10 to 30 percent fine gravel.

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

Bt horizon
Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 3 or 4 in upper part, ranging to 6 in lower part.
Texture: Clay loam or clay, commonly gravelly.
Structure: Prismatic or angular blocky.

C horizon
Present in some pedons.

COMPETING SERIES: There are no other series in this family at the present time.

GEOGRAPHIC SETTING: Chad soils are on mountain side slopes. These soils formed in residuum derived from chert and shale, with small components of loess and volcanic ash. Slopes are 15 to 50 percent. Elevations are 1,829 to 2,499 meters. The climate is cool, semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 300 to 4l0 mm; mean annual temperature is 6 to 7 degrees C, and the frost-free season is about 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cleavage, Robson, Softscrabble, and Swanner soils. Cleavage, Robson, and Swanner soils have a lithic contact at depths less than 50 cm. Softscrabble soils have a fine-loamy particle-size control section and a Pachic epipedon.

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

USE AND VEGETATION: Rangeland and wildlife habitat. The present vegetation is mainly mountain big sagebrush, rabbitbrush, bluebunch wheatgrass, pine bluegrass, bottlebrush squirreltail, and serviceberry.

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

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

SERIES ESTABLISHED: Eureka County Area, Nevada, 1983.

REMARKS: Diagnostic horizons and features recognized in this pedon:
Mollic epipedon - The zone from the soil surface to about 25 cm (the A1 and A2 horizons).
Argillic horizon - The zone from about 43 to 107 cm (the Bt1 and Bt2 horizons).
Paralithic contact - The boundary at about 107 cm (the Cr horizon).
Particle-size control section - The zone from about 43 to 93 cm (the Bt1 and part of the Bt2 horizons).

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National Cooperative Soil Survey
U.S.A.