LOCATION STAMPEDE NV+OR

Established Series
Rev. JVC/JBF
11/2016

STAMPEDE SERIES

The Stampede series consists of moderately deep to a duripan, well drained soils that formed in eolian material and alluvium derived from volcanic rock such as tuff or from mixed rocks. Stampede soils are on fan remnants and lava plateaus. Slopes are 1 to 20 percent. The mean annual precipitation is about 300 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Fine, smectitic, frigid Vertic Durixerolls

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

A1--0 to 10 cm; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak thick platy structure parting to moderate fine subangular blocky; slightly hard, friable, slightly sticky and nonplastic; many fine roots; many fine vesicular pores; 25 percent gravel; neutral (pH 6.8); clear smooth boundary. (5 to 13 cm thick)

A2--10 to 24 cm; dark grayish brown (10YR 4/2) gravelly clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and common fine roots; common very fine tubular, and many very fine interstitial pores; 15 percent gravel; neutral (pH 6.8); clear smooth boundary. (8 to 20 cm thick)

BEt--24 to 30 cm; light brownish gray (10YR 6/2) gravelly clay loam, very dark grayish brown (10YR 3/2) moist; strong medium and fine subangular blocky structure; hard, friable, very sticky and very plastic; many very fine and fine roots; many very fine interstitial, common very fine and few fine tubular pores; many uncoated sand grains; few faint clay films on faces of peds; 20 percent gravel; neutral (pH 6.8); abrupt wavy boundary. (0 to 20 cm thick)

Btss--30 to 55 cm; brown (10YR 5/3) clay, brown (10YR 4/3) moist; strong and moderate medium prismatic structure; very hard, very firm, very sticky and very plastic; few fine and medium, common very fine imped roots; common very fine and fine tubular pores; many pressure cutans and slickensides on faces of peds; neutral (pH 6.8); clear wavy boundary. (12 to 33 cm thick)

Bt--55 to 71 cm; brown (10YR 5/3) clay, dark yellowish brown (10YR 4/4) moist; moderate medium and fine subangular blocky structure; very hard, firm, very sticky and very plastic; few very fine roots; few fine tubular pores; many distinct clay films lining pores; common pressure cutans on faces of peds; neutral (pH 7.0); abrupt smooth boundary. (0 to 33 cm thick)

Bqkm--71 to 84 cm; light gray (10YR 7/2) cemented material, yellowish brown (10YR 5/4) moist; massive; extremely hard, extremely firm; indurated by opaline silica; few very fine tubular pores; few distinct clay films on fracture surfaces; thin (0.1 to 1 mm) laminae of opaline silica on the horizon surface, along fractures, and lining pores; secondary carbonates segregated as coats and filaments; noneffervescent matrix with violently effervescent coats and filaments; slightly alkaline (pH 7.6). (13 to 25 cm thick)

TYPE LOCATION: Elko County, Nevada; about 26 miles north of Carlin between the Independence and Tuscarora Mountains; approximately 1,580 feet north and 250 feet west of the southeast corner of section 21, T. 37 N., R. 52 E.; USGS Beaver Creek 7.5 minute topographic quadrangle; latitude 41 degrees 04 minutes 49 seconds N and longitude 116 degrees 07 minutes 36 seconds W; WGS84 Decimal Degrees 41.0802778 latitude, -116.1263889 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry July to October; aridic moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 33 cm; may include the Btss horizon in some pedons.
Depth to duripan: 50 to 94 cm.
Other features: Noncemented soil materials such as extremely gravelly loamy sand, gravelly sandy loam, or very gravelly sandy loam are below the duripan to a depth of at least 200 cm; Cracks 5 to 10 millimeters wide are commonly present through the A2, Bt/E, and Btss horizons.

Particle-size control section - Clay content: 35 to 55 percent.
Rock fragments: 5 to 25 percent, mainly gravel and cobbles. Lithology of fragments is mixed.

A horizons
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Reaction: Slightly acid or neutral.
Organic matter content: 1 to 3 percent.
Other features: Value of 6 dry and 4 moist are common in the Bt/E horizon (when present).

Btss and Bt horizons
Hue: 10YR or 7.5YR.
Value: 4 through 6 dry, 3 through 5 moist.
Chroma: 2 through 4, dry or moist.
Texture: Clay, silty clay, or cobbly clay loam.
Rock fragments: Up to 25 percent in any one horizon.
Structure: Moderate or strong medium or coarse prismatic or fine to coarse subangular or angular blocky.
Reaction: Neutral through moderately alkaline.
Slickensides: Present in the Btss horizon on horizontal faces (bases) of prisms.

Bqkm horizon
Reaction: Slightly alkaline or moderately alkaline.
Effervescence: Noneffervescent to strongly effervescent in the matrix but contains few to many coats of secondary carbonates are on the horizon surface or are lining fractures.
Other features: Thin subhorizons of very gravelly sandy clay loam are present above the Bqkm horizon in some pedons.

COMPETING SERIES: There are currently no other series in this family.

GEOGRAPHIC SETTING: Stampede soils are on fan remnants and lava plateaus. These soils formed in eolian material and alluvium derived from volcanic rock such as tuff or from mixed rocks. Slopes are 1 to 20 percent. Elevations range from 1,220 to 2,130 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 250 to 360 mm, the mean annual temperature is 6 to 7 degrees C., and the frost-free period is 50 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Donna, Short Creek, and Simon soils. Donna soils have a very fine particle-size control section. Short Creek and Simon soils do not have duripans.

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

USE AND VEGETATION: Stampede soils are used for rangeland and wildlife habitat. The principal vegetation is big sagebrush, bluebunch wheatgrass, Thurber's needlegrass, bottlebrush squirreltail, basin wildrye, cheatgrass, and Douglas rabbitbrush.

DISTRIBUTION AND EXTENT: North-central Nevada and south-central Oregon. These soils are extensive with about 152,000 acres of the series mapped to date. The series concept and main acreage is in MLRA 25 in Nevada, while other acreage occurs in MLRA 23 in Oregon and MLRA 28B in Nevada.

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

SERIES ESTABLISHED: Elko County (Diamond Valley Area), Nevada, 1971.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 24 cm (A1 and A2 horizons).
Slickensides - The zone from 30 to 58 cm (Btss horizon).
Argillic horizon - The zone from 30 to 71 cm (Btss and Bt horizons).
Duripan - The zone from 71 to 84 cm (Bqkm horizon).
Particle-size control section - The zone from 30 to 71 cm (Btss and Bt horizons).

ADDITIONAL DATA: A pedon of Stampede is reported in Soil Survey Investigations Report No. 23 on pages 204-205.
Previous authors include: RAF-PWB-TM.

National Cooperative Soil Survey
U.S.A.