LOCATION LORGANA                 NV

Tentative Series
Rev. BKP/PWB/JBF
01/2017

LORGANA SERIES

The Lorgana series consists of very deep, well drained soils that formed in residuum and colluvium derived from limestone and dolomite. Lorgana soils are on mountains. Slopes are 8 to 50 percent. The mean annual precipitation is about 640 mm and the mean annual temperature is about 4 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, carbonatic Pachic Haplocryolls

TYPICAL PEDON: Lorgana gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is covered with approximately 10 percent gravel and 5 percent cobbles. A discontinuous layer about 1 cm thick of slightly decomposed leaves and twigs is also present.

A1--0 to 10 cm; very dark grayish brown (10YR 3/2) gravelly loam, black (10YR 2/1) moist; moderate fine and medium subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine and fine roots; many very fine and fine tubular pores; 10 percent gravel and 5 percent cobbles; slightly effervescent; slightly alkaline (pH 7.6); clear smooth boundary. (8 to 12 cm thick)

A2--10 to 36 cm; very dark grayish brown (10YR 3/2) very cobbly loam, black (10YR 2/1) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine and medium, and few coarse roots; many very fine and fine, and few medium tubular pores; 20 percent gravel, 20 percent cobbles, and 10 stones; slightly effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (20 to 35 cm thick)

Bk1--36 to 66 cm; brown (10YR 5/3) extremely gravelly loam, dark brown (10YR 3/3) moist; strong medium and coarse subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many very fine and fine roots; many very fine and fine tubular pores; 50 percent gravel, 20 percent cobbles, and 5 percent stones; disseminated calcium carbonate throughout the matrix and few very fine calcium carbonate concretions on the bottom of rock fragments; strongly effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (20 to 50 cm thick)

Bk2--66 to 152 cm; pale brown (10YR 6/3) very gravelly loam, dark brown (10YR 3/3) moist; strong medium subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine roots; few very fine tubular pores; 40 percent gravel, 10 percent cobbles, and 5 percent stones; disseminated calcium carbonate throughout the matrix and few very fine calcium carbonate concretions on the bottom of rock fragments; strongly effervescent; slightly alkaline (pH 7.8).

TYPE LOCATION: White Pine County, Nevada; on the Antelope Mountains; section 8, T. 23 N., R. 67 E.; USGS Sawmill Canyon 7.5 minute topographic quadrangle; latitude 39 degrees 53 minutes 28.4 seconds N and longitude 114 degrees 25 minutes 34.0 seconds W; WGS84 Decimal Degrees 39.8912000 latitude, -114.4261000 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist during late fall through early summer, dry mid-summer through mid-fall; typic xeric soil moisture regime.
Mean annual soil temperature: 3 to 7 degrees C.
Mean summer soil temperature: 6 to 8 degrees C.
Mollic epipedon thickness: 40 cm to 80 cm.
Calcium carbonate equivalent: 4 to 10 percent in the less than 2 mm fraction.

Particle-size control section - Clay content: 20 to 27 percent.
Rock fragments: Averages 45 to 70 percent, mainly gravel. Lithology of rock fragments are limestone or dolomite.

A horizons
Chroma: 1 or 2 moist.
Reaction: Neutral or slightly alkaline.
Organic matter content: 3 to 8 percent.

Bk1 horizon
Value: 4 or 5 dry, 2 through 5 moist.
Chroma: 2 or 3 dry.
Structure: Weak through strong, fine through coarse, subangular blocky.
Consistence: Soft or slightly hard, slightly sticky and moderately sticky, and slightly plastic or moderately plastic.
Texture: loam or silt loam.
Texture modifier: very gravelly, extremely gravelly, or very cobbly.
Reaction: Neutral or slightly alkaline.
Identifiable secondary carbonates: finely disseminated throughout, few less than 1 mm thick concretions on the bottom of rock fragments, or few fine soft masses throughout the matrix. Total percent by volume is less than 5 percent.
Organic matter content: 1 to 3 percent.

Bk2 horizon
Value: 3 through 6 moist.
Chroma: 3 or 4 moist.
Structure: Weak through strong, very fine through medium, subangular blocky or massive.
Consistence: Soft through hard dry, very friable through firm friable moist.
Identifiable secondary carbonates: finely disseminated throughout, common less than 1 mm thick concretions on the bottom of rock fragments, or less than 5 percent fine soft masses throughout the matrix. Total percent by volume is less than 5 percent.
Organic matter content: 0.5 to 1.5 percent.

COMPETING SERIES: Currently there are no competing series.
GEOGRAPHIC SETTING: Lorgana soils are on mountains. They typically occur on upper backslope positions. These soils formed in colluvium over residuum derived from limestone and dolomite. Slopes are 8 to 50 percent. Elevations range from 2,440 to 3,360 meters. The climate is semiarid with cold, moist winters and cool, dry summers. The mean annual precipitation is 560 to 760 mm, the mean annual temperature is 4 to 6 degrees C, and the frost-free period is 40 to 60 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Haunchee, Hardzem, and the competing Hardol soils. Haunchee soils are shallow to lithic contacts and do not have calcic horizons. Hardzem soils are moderately deep to paralithic contacts, have ochric epipedons and argillic horizons.

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

USE AND VEGETATION: Lorgana soils are used for livestock grazing and wildlife habitat. The present vegetation is bluebunch wheatgrass, Letterman's needlegrass, Columbia needlegrass and mountain big sagebrush.

DISTRIBUTION AND EXTENT: Central Nevada. These soils are moderately extensive. MLRA 28B.

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

SERIES ESTABLISHED: Humboldt National Forest, Nevada North Part, 2019.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 66 cm (A1, A2, and Bk1 horizons).
Particle-size control section - The zone from 25 to 100 cm (bottom part of A2, Bk1, and part of Bk2 horizons).

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National Cooperative Soil Survey
U.S.A.