LOCATION CARSTUMP NV

Established Series
Rev. ELS/TM/RLB/JBF
11/2018

CARSTUMP SERIES

The Carstump series consists of moderately deep, well drained soils that formed in residuum and colluvium derived from volcanic rocks, chert and shale with minor additions of loess and ash. Carstump soils are on summits, and side slopes of mountains, hills and plateaus. Slopes are 4 to 50 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Calciargidic Argixerolls

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

A1--0 to 10 cm; grayish brown (10YR 5/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine and medium granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, common fine, and few medium roots; many very fine and fine tubular and interstitial pores; 50 percent gravel; neutral (pH 6.8); clear smooth boundary. (5 to 18 cm thick)

A2--10 to 28 cm; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak fine granular structure; slightly hard, friable, moderately sticky and slightly plastic; common very fine, and few fine, medium and coarse roots; common fine continuous tubular and vesicular pores; 30 percent gravel; neutral (pH 6.8); abrupt smooth boundary. (18 to 23 cm thick)

AB--28 to 38 cm; light brownish gray (10YR 6/2) very gravelly sandy clay loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, friable, moderately sticky and moderately plastic; few very fine, fine, and medium roots; few very fine continuous tubular, and many very fine vesicular pores; many bleached sand grains; 40 percent gravel; neutral (pH 6.8); abrupt smooth boundary. (0 to 13 cm thick)

Bt--38 to 51 cm; brown (10YR 5/3) very gravelly clay, dark yellowish brown (10YR 4/4) moist; moderate very fine and fine angular blocky structure; very hard, firm, very sticky and moderately plastic; very fine very fine roots; common very fine continuous tubular pores; continuous distinct clay films on faces of peds and in pores; 40 percent gravel; neutral (pH 7.0); gradual wavy boundary. (8 to 38 cm thick)

Btk--51 to 74 cm; yellowish brown (10YR 5/4) very gravelly clay, yellowish brown (10YR 5/4) moist; strong very fine and fine angular blocky structure; very hard, friable, very sticky and moderately plastic; common very fine continuous tubular pores; continuous distinct clay films on faces of peds and in pores; few fine filaments of lime; strongly effervescent; 35 percent gravel; moderately alkaline (pH 8.4); clear irregular boundary. (13 to 46 cm thick)

R--74 to 91 cm; fractured chert bedrock with lime coatings in fractures.

TYPE LOCATION: Elko County, Nevada; about 6 miles southeast of Carlin; approximately 2,100 feet north and 250 feet east of the southwest corner of section 25, T.32 N., R. 52 E.; USGS Carlin East 7.5 minute topographic quadrangle; latitude 40 degrees 37 minutes 44 seconds N and longitude 116 degrees 5 minutes 2 seconds W; WGS84 Decimal Degrees 40.6288889 latitude, -116.083889 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist November to June, usually dry July through October. Aridic soil moisture regime bordering on xeric
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 38 cm, includes the upper part of the argillic horizon in some pedons.
Depth to secondary lime: 50 to 90 cm.
Depth to bedrock: 50 to 100 cm.

Particle-size control section - Clay content: 40 to 55 percent.
Rock fragments: 35 to 50 percent, mainly gravel and cobbles.

A and AB horizons
Value: 5 dry, 3 moist. Value of 6 dry is below 25 cm in some pedons. Thin upper horizons of some pedons have a moist value of 4 with the top 18cm of soil averaging a color value of 3 moist.
Chroma: 2 or 3.
Reaction: Neutral or slightly alkaline.

Bt and Btk horizons
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4.
Structure: Angular blocky or subangular blocky.
Texture: Very gravelly clay, very cobbly clay. Subhorizons of very gravelly silty clay loam or clay loam are in some pedons.
Consistence: Slightly hard to very hard, dry; sticky or very sticky and plastic or very plastic; wet.
Reaction: Neutral or slightly alkaline in the noncalcareous upper part; moderately alkaline to strongly alkaline in the lower part.
Other features: Soft powdery lime in filaments or soft masses is in the Btk horizon. The Bt horizons are noneffervescent and the Btk horizons are slightly effervescent to violently effervescent.

COMPETING SERIES: These are the Cronks and Golsum series.

Cronks soils are more than 150 cm to bedrock. Golsum soils have paralithic contacts at depths of 50 to 100 cm.

GEOGRAPHIC SETTING: Carstump soils are on summits and side slopes of mountains, hills and plateaus. These soils formed in residuum and colluvium derived from volcanic rocks, chert and shale with minor additions of loess and volcanic ash. Elevations are 1,520 to 2,140 meters. Slopes are 4 to 50 percent. The climate is cool, semiarid with hot, dry summers and cold, moist winters. The mean annual precipitation is 200 to 300 mm; mean annual temperature is 6 to 7 degrees C., and the frost-free season is 80 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Mascamp soils. Mascamp soils are shallow to hard bedrock and have a loamy-skeletal control sections.

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

USE AND VEGETATION: Used for livestock grazing and wildlife habitat. The vegetation is principally big sagebrush, Douglas rabbitbrush, cheatgrass, Sandberg bluegrass and basin wildrye.

DISTRIBUTION AND EXTENT: Northern Nevada. These soils are not extensive. MLRA 25.

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

SERIES ESTABLISHED: Elko County (Tuscarora Mountain Area), Nevada, 1975.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 28 cm (A1 and A2 horizons.)
Argillic horizon - The zone from about 38 to 74 cm (the Bt and Btk horizons).
Aridic feature - Aridic moisture bordering on xeric.
Calcic horizon or soft, powdery lime - The accumulation of secondary lime in the zone from about 50 to 74 cm (Btk horizon).
Particle-size control section - The zone from about 38 to 74 cm (Bt and Btk horizons).

National Cooperative Soil Survey
U.S.A.