LOCATION MASCAMP                 NV+CA OR

Established Series
Rev. JBF/TM
09/2019

MASCAMP SERIES

The Mascamp series consist of shallow well drained soils that formed in residuum from basic tuff with minor admixtures of alluvium from andesite and basalt Mascamp soils are rolling foothills and mountains. Slopes range from 0 to 50 percent. The mean annual precipitation is about 360 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Aridic Lithic Argixerolls

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

A1--0 to 15 cm; dark grayish brown (10YR 4/2) very gravelly loam, very dark grayish brown (10YR 3/2) moist; moderate very fine and fine granular structure; soft, very friable, nonsticky and slightly plastic; common very fine and fine roots; many fine and very fine interstitial pores; 45 percent gravel; neutral (pH 6.6); clear wavy boundary. (0 to 20 cm thick)

A2--15 to 33 cm; brown (10YR 5/3) very gravelly loam, dark brown (10YR 3/3) moist; weak medium and coarse subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and few fine roots; many very fine and fine interstitial pores; 50 percent gravel; neutral (pH 6.6); abrupt wavy boundary. (10 to 20 cm thick)

Bt--33 to 48 cm; brown (10YR 5/3) extremely gravelly clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine and few fine roots; many very fine and fine tubular pores; 60 percent gravel; common faint clay films on faces of peds and many faint clay films in pores; neutral (pH 6.6); abrupt smooth boundary. (8 to 30 cm thick)

R--48 to cm; light gray (5Y 7/1) carbonate coated fractured tuff bedrock

TYPE LOCATION: Eureka County, Nevada. About 2,300 feet north and 300 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 47.5 seconds N and longitude 116 degrees 5 minutes 3.8 seconds W; WGS84 Decimal Degrees 40.6298611 latitude, -116.0843889 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry, moist late fall, winter and spring, dry summer and early fall. Aridic moisture regime bordering on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Depth to bedrock: 36 to 50 cm.
Mollic epipedon: 36 to 50 cm encompasses all, or part, of the argillic horizon.
Other features: The sola are usually noncalcareous but may have soft carbonate segregations in the lower 5 or 8 cm. Soft carbonate segregations coat the underlying bedrock.

Particle-size control section - Clay content: Averages 20 to 35 percent.
Rock fragments: Average 60 to 75 percent.

A horizon
Value: 4 through 6 dry, 2 or 3 moist,
Chroma: 2 or 3.
When the surface 18 cm are mixed, color values are less than 5.5 dry.
Structure: Weak or moderate, very thin to medium platy, fine or medium granular, subangular blocky or massive.
Consistence: Soft or slightly hard.

Bt horizon
Hue: 10YR and 7.5YR
Value: 5 or 6 dry, 3 or 4 moist,
Chroma: 3 or 4.
Texture: Sandy clay loam but includes clay loam or loam,
Rock fragments: 60 to 75 percent.
Structure: Weak or moderate, fine to coarse subangular blocky but may have weak, fine or medium prismatic
Clay content: When the argillic horizon is mixed, the weighted average clay content is less than 35 percent

COMPETING SERIES: These are the Anaud, Cleavage, Cleavmor, Cropper, Gaciba, Granquin, Grosschat, Horsetrack, Pernty, Shalper, Slatter, and Tractuff soils.

Anaud, Granquin, Grosschat, and Tractuff soils are moist 10 to 20 days between July and October due to convection storms. Cleavage soils have mollic epipedon that range from 18 to 25 cm and does not include the argillic horizon. Cleavmor soils have Btk horizons containing few to many filaments and seams of carbonate. Cropper soils have a mollic epipedon are 18 to 25 cm thick. Gaciba, Horsetrack, Pernty and Shalper soils average 35 to 60 percent coarse fragments. Slatter soils are less than 25 cm deep.

GEOGRAPHIC SETTING: Mascamp soils are foothills and mountain slopes having gradients of 0 to 50 percent. These soils developed in residuum derived from basic tuffs with minor admixtures of alluvium from andesite and basalt, and volcanic ash. These soils are at elevations of 1,520 to 1,980 meters in a cool, continental climate having mean annual precipitation of 250 to 400 mm that comes mostly as snow. The mean annual air temperature ranges from 5 to 7 degrees C., and the average frost-free season ranges from 50 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are Carstump, Chen and Ramires soils. Chen soils have more than 38 percent clay in the particle-size control section. Ramires soils are fine and moderately deep to a lithic contact.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; surface runoff is slow to rapid; permeability is moderately slow; moderately high saturated hydraulic conductivity.

USE AND VEGETATION: Used for livestock grazing. Big sagebrush, Thurber needlegrass, bluebunch wheatgrass, bottlebrush squirreltail, Sandberg bluegrass, and low Douglas rabbitbrush the higher precipitation range includes Idaho fescue, and mountain big sagebrush.

DISTRIBUTION AND EXTENT: Mascamp soils occur in northern Nevada and in southeastern Oregon. The soils are of small extent. MLRAs 24 and 25 in Nevada, MLRA 21 in Oregon, MLRAs 21, 23 and 29 in California.

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

SERIES ESTABLISHED: Surprise Valley-Home Camp Area, Lassen and Modoc Counties, California and Washoe County, Nevada, 1968.

REMARKS: Mascamp soils were formerly classified as Brown soils. The series type was moved to Eureka County in 2006 to better reflect the series concept.

Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 33 cm (A1 and A2 horizons).
Argillic horizon - The zone from 33 to 48 cm (Bt horizon).
Lithic contact - The boundary at about 48 cm (R layer).
Particle size control section - The zone from 33 to 48 cm (Bt horizon).

Classification was updated to 11th edition on 07/2011 changed Lithic Argixerolls to Aridic Lithic Argixerolls.

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National Cooperative Soil Survey
U.S.A.