LOCATION LITTLEMUD NVTentative Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Pachic Argicryolls
TYPICAL PEDON: Littlemud gravelly loam--rangeland. (colors are for dry soil unless otherwise noted.)
A1--0 to 3 inches; very dark grayish brown (10YR 3/2) gravelly loam, black (10YR 2/1) moist; moderate fine granular structure; soft, very friable, slightly sticky and nonplastic; many very fine and many fine roots; many very fine interstitial pores; 25 percent pebbles; moderately acid (pH 6.0); clear smooth boundary. (2 to 4 inches thick)
A2--3 to 10 inches; very dark grayish brown (10YR 3/2) gravelly loam, black (10YR 2/1) moist; moderate medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine, many fine, common medium, and few coarse roots; many very fine interstitial and common very fine and fine tubular pores; 25 percent pebbles; slightly acid (pH 6.2); clear smooth boundary. (5 to 8 inches thick)
A3--10 to 16 inches; dark brown (10YR 3/3) gravelly loam, black (10YR 2/1) moist; moderate coarse subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine, many fine, common medium, and common coarse roots; many very fine and fine tubular pores; 30 percent pebbles; slightly acid (pH 6.2); abrupt wavy boundary. (4 to 8 inches thick)
Bt1--16 to 22 inches; pale brown (10YR 6/3) very gravelly clay loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine and common fine roots; many very fine and many fine tubular pores; common distinct clay films on faces of peds and lining pores; 45 percent pebbles; slightly acid (pH 6.4); abrupt wavy boundary. (4 to 10 inches thick)
Bt2--22 to 38 inches; pale brown (10YR 6/3) very gravelly clay loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few very fine and few fine roots; many very fine and many fine tubular pores; common distinct clay films on faces of peds and lining pores; 45 percent pebbles; slightly acid (pH 6.4); abrupt smooth boundary. (10 to 18 inches thick)
R--38 inches; unweathered quartzite.
TYPE LOCATION: Elko County, Nevada; on the Humboldt National Forest about 0.5 mile southeast of Rosebud Mountain; 500 feet west and 2000 feet south of the northeast corner of section 34, T. 46 N., R. 56 E.; USGS Tennessee Mountain 7.5 minute topographic quadrangle; 41 degrees 45 minutes 08 seconds north latitude and 115 degrees 38 minutes 02 seconds west longitude, NAD27.
RANGE IN CHARACTERISTICS:
Soil moisture - Moist in the moisture control section in winter and spring, usually dry from late July through early October; Completely moist for 110 to 140 days following the winter solstice; Typic xeric moisture regime.
Mean annual soil temperature - 40 to 44 degrees F.
Mean summer soil temperature - 52 to 56 degrees F.
Mollic epipedon thickness - 16 to 20 inches; does not include the Bt horizons.
Depth to base of argillic horizon - 30 to 40 inches.
Depth to bedrock - 30 to 40 inches to a lithic contact.
Particle-size control section - Clay content: 25 to 35 percent; Rock fragments: 35 to 60 percent, mainly pebbles. Lithology of fragments are quartzite or rhyolite.
A horizons - Value: 3 or 4 dry, 2 or 3 moist.
Chroma: 1 through 3, dry or moist.
Reaction: Moderately acid or slightly acid.
Organic matter content: 3 to 6 percent.
Other features: The A1 horizon exhibits strong hydrophobic characteristics.
Bt horizons - Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Very gravelly loam or very gravelly clay loam.
Structure: Weak or moderate fine or medium subangular blocky.
Consistence: Slightly hard or hard, dry.
COMPETING SERIES: These are the Angelwhine (T), Aspetill (T), Badwater, Bickmore, Bluebell, Booneville, Buena Vista, Dab (T), Delhew (T), Geemore, Hawkinspeak (T), Keman, Lostcannon (T), Monibasin (T), Parkalley (T), Parkay, Redbird, Rutherford, Sweetmount (T), and Woodhurst series.
Angelwhine, Aspetill, Badwater, Booneville, Dab, Delhew, Keman, Lostcannon, Monibasin, Parkalley, Parkay, and Redbird soils are very deep. Bickmore soils are dominated by cobbles in the particle-size control section and have subhorizons of the argillic horizon with identifiable secondary carbonates and 15 to 40 percent calcium carbonate equivalent. Bluebell soils are dominated by stones in the particle-size control section, have mollic epipedons that range from 20 to 35 inches thick, and have mean summer soil temperatures of 58 to 60 degrees F. Buena Vista soils have 5 to 18 percent clay, are dominated by stones in the particle-size control section, and have subhorizons of the argillic horizon with identifiable secondary carbonates. Geemore soils have calcic horizons and horizons with silica cementation within 25 inches of the soil surface. Hawkinspeak soils have mollic epipedons that include the subhorizons of the argillic horizon and have rock fragments which are tuff, tuff-breccia, and andesite. Rutherford soils have mollic epipedons that range from 20 to 30 inches thick within subhorizons of the argillic horizon. Sweetmount soils are deep to paralithic contacts and have subhorizons of the argillic horizon with 27 to 50 percent clay. Woodhurst soils are dominated by stones in the particle-size control section and have an ustic moisture regime.
GEOGRAPHIC SETTING: Littlemud soils are on mountains. They typically occur on backslope positions. These soils formed in colluvium and residuum derived from quartzite or rhyolite. Slopes are 15 to 75 percent. Elevations range from 7,500 to 9,000 feet. The climate is subhumid with cold, moist winters and cool, dry summers. The mean annual precipitation is 20 to 30 inches, the mean annual temperature is 37 to 43 degrees F., and the frost-free period is 50 to 70 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hackwood and Inpendence soils. Hackwood soils are fine-loamy, very deep, and have thick mollic epipedons. Inpendence soils are loamy-skeletal, very deep, and have thick umbric epipedons.
DRAINAGE AND PERMEABILITY: Well drained; very high surface runoff; moderately slow permeability.
USE AND VEGETATION: Littlemud soils are used for rangeland and wildlife habitat. The present vegetation is mainly snowbrush ceanothus.
DISTRIBUTION AND EXTENT: Northeastern Nevada. These soils are not extensive. MLRA 25.
MLRA OFFICE RESPONSIBLE: Reno, Nevada.
SERIES PROPOSED: Elko County (Humboldt National Forest), Nevada, 1995. The name is taken from a historical mine in the area.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 16 inches (A1, A2, and A3 horizons).
Argillic horizon - The zone from 16 to 38 inches (Bt1 and Bt2 horizons).
Lithic contact - The boundary at 38 inches to underlying hard, unweathered bedrock (R layer).
Particle-size control section - The zone from 16 to 36 inches (Bt1 horizon and part of the Bt2 horizon).