LOCATION MIDRAW                  NV+ID

Established Series
Rev. RAF-RLB-GHL-JBF
09/2019

MIDRAW SERIES

The Midraw series consists of shallow over an indurated duripan, well drained soils that formed in colluvium and residuum derived from rhyolite, andesite, basalt, or rhyolitic tuff with a component of loess and volcanic ash. Midraw soils are on crests, summits, shoulders, side slopes of structural benches, plateaus, foothills, hills and mountains. Slopes are 0 to 50 percent. Mean annual precipitation is about 230 mm and the mean annual temperature is about 8 degrees C.

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

TYPICAL PEDON: Midraw gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with 10 percent gravel and 5 percent cobbles.

A--0 to 5 cm; pale brown (10YR 6/3) gravelly loam, dark brown (10YR 3/3) moist; moderate thick platy structure; soft, very friable, slightly sticky and slightly plastic; few very fine roots; common very fine vesicular pores; 15 percent gravel, 5 percent cobbles; neutral (pH 6.6); abrupt smooth boundary. (5 to 15 cm thick)

Bt1--5 to 15 cm; pale brown (10YR 6/3) gravelly clay loam, brown (10YR 4/3) moist; weak medium subangular blocky structure parting to moderate very fine subangular blocky; slightly hard, friable, moderately sticky and moderately plastic; few very fine roots; few fine and very fine tubular pores; few faint clay films lining pores; 15 percent gravel; neutral (pH 6.6); clear smooth boundary. (5 to 13 cm thick)

Bt2--15 to 33 cm; light yellowish brown (10YR 6/4) gravelly clay, dark yellowish brown (10YR 4/4) moist; weak medium prismatic structure parting to strong fine angular blocky; very hard, very firm, very sticky and very plastic; few fine and very fine roots; few fine tubular pores; many distinct clay films on peds and lining pores; 10 percent gravel and 5 percent cobbles; neutral (pH 7.2); gradual smooth boundary. (8 to 18 cm thick)

Bt3--33 to 43 cm; light yellowish brown (10YR 6/4) gravelly clay, dark yellowish brown (10YR 4/4) moist; strong fine angular blocky structure; very hard, very firm, very sticky and very plastic; few very fine roots; few fine tubular pores; many distinct clay films on peds and lining pores; 10 percent gravel and 5 percent cobbles; slightly effervescent; neutral (pH 7.2); gradual smooth boundary. (0 to 5 cm thick)

Bqk--43 to 48 cm; very pale brown (10YR 7/3) very gravelly clay loam, yellowish brown (10YR 5/4) moist; massive; hard, firm, moderately sticky and moderately plastic; 50 percent gravel size duripan fragments; violently effervescent; carbonate is disseminated; moderately alkaline (pH 8.0); clear smooth boundary (0 to 13 cm thick)

Bqkm--48 to 64 cm; very pale brown (10YR 7/3) indurated duripan; massive, extremely hard, extremely firm; silica laminae are 0.5 to 2 mm thick; duripan composed of thin to thick alternating weakly cemented and indurated layers; abrupt smooth boundary. (10 to 38 cm thick)

R--64 cm; rhyolite.

TYPE LOCATION: Elko County, Nevada; Owyhee Desert, approximately 27 miles northwest of Wilson Reservoir; approximately 1,400 feet west of the northeast corner of section 4, T. 46 N., R. 47 E.; USGS Rubber Hill 7.5 minute topographic quadrangle; latitude 41 degrees 55 minutes 22 seconds N and longitude 116 degrees 42 minutes 57 seconds W; WGS84 Decimal Degrees 41.9227778 latitude, -116.7158333 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry; moist in winter and spring, dry in late June through October; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Depth to base of Bt horizon: 36 to 50 cm.
Depth to duripan: 36 to 50 cm.
Depth to bedrock: 50 to 89 cm.

Particle-size control section - Clay content: 35 to 45 percent.
Rock fragments: 15 to 35 percent.

A horizon
Value: 6 or 7 dry, 3 through 5 moist.
Chroma: 2 or 3.
Reaction: Neutral through moderately alkaline.

Bt horizon
Value: 5 or 6 dry, 3 through 5 moist.
Chroma: 2 through 4.
Texture: Gravelly clay loam, gravelly silty clay loam, gravelly clay or cobbly clay.
Consistence: Friable, firm or very firm, moist.
Structure: Prismatic, subangular blocky or angular blocky.
Rock fragments: 15 to 35 percent.
Reaction: Neutral through moderately alkaline.
Other features: Some pedons have durinodes or pan fragments in the lower subhorizon.

Bqk horizon
Hue: 7.5YR or 10YR.
Value: 6 or 7 dry, 3 through 5 moist
Chroma: 3 or 4.
Structure: Subangular blocky or is massive.
Consistence: Friable or firm, moist; slightly plastic or plastic, wet.

Bkqm horizon
Hue: 7.5YR or 10YR.
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 3 or 4.

COMPETING SERIES: These are the Buffaran, Indian Creek, Lud and Norfork series.

Buffaran soils lack a lithic contact within a depth of 50 to 100 cm. Indian Creek soils lack bedrock within a depth of 50 to 100 cm and have an abrupt textural boundary. Lud soils have less than 15 percent gravel in the Bt. Norfork soils are less than 36 cm to the base of the argillic horizon.

GEOGRAPHIC SETTING: Midraw soils are on crests, summits, shoulders, side slopes of structural benches, plateaus, foothills, hills and mountains. These soils formed in colluvium and residuum derived from rhyolite, andesite, basalt, and rhyolitic tuff with a component of loess and volcanic ash. Elevations are 975 to 1,895 meters. Slopes are 0 to 50 percent. Climate is cool and semiarid with warm, dry summers and cool, moist winters. Mean annual precipitation is 200 to 300 mm; mean annual temperature is 7 to 10 degrees C., and the frost-free season is 90 to 125 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Colthorp and Troughs soils. Colthorp soils have a loamy particle-size control section. Troughs soils have a loamy-skeletal particle-size control section.

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

USE AND VEGETATION: Rangeland and wildlife habitat. Vegetation is mainly Wyoming big sagebrush, Sandberg bluegrass, bluebunch wheatgrass, Douglas rabbitbrush, and bottlebrush squirreltail.

DISTRIBUTION AND EXTENT: North-central Nevada and Southwestern Idaho. MLRA 25, 24 and 23. Midraw soils are of small extent.

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

SERIES ESTABLISHED: Lander County (North Part), Nevada, 1985.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the surface to 5 cm (A horizon).
Argillic horizon - The zone from 5 to 43 cm (Bt1, Bt2 and Bt3 horizons).
Indurated duripan - The zone from 48 to 64 cm (Bqkm horizon)
Lithic contact - The boundary at 64 cm (R layer).
Xeric feature - Soil has organic matter content that meets requirements for xeric.
Particle-size control section - The zone from 5 to 48 cm (Bt1, Bt2, Bt3, and Bkq horizons).

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National Cooperative Soil Survey
U.S.A.