LOCATION BILBO                   NV

Established Series
Rev. MJN-PWB-TM-JBF
10/2015

BILBO SERIES

The Bilbo series consists of very deep, well drained soils that formed in alluvium derived from mixed rocks and in some areas colluvium from shale, sandstone and conglomerate. Bilbo soils occur on side slopes of fan piedmont remnants, fan remnant partial ballenas, hills, plateaus and some inset fan remnants. Slopes are 2 to 75 percent. The mean annual precipitation is about 250 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Xeric Haplargids

TYPICAL PEDON: Bilbo gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.) The soil surface is partially covered with 60 percent gravel.

A1--0 to 5 cm; grayish brown (10YR 5/2) gravelly loam, very dark grayish brown (10YR 3/2) moist; weak thick platy structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; many very fine vesicular pores; 20 percent gravel; slightly alkaline (pH 7.4); abrupt smooth boundary. (5 to 20 cm thick)

A2--5 to 10 cm; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; moderate very fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots; common very fine vesicular and few very fine tubular pores; 15 percent gravel; slightly alkaline (pH 7.6); clear wavy boundary. (0 to 10 cm thick)

Bt1--10 to 20 cm; pale brown (10YR 6/3) very gravelly clay loam, brown (10YR 4/3) moist; weak medium prismatic structure parting to moderate medium subangular blocky; hard, friable, moderately sticky and moderately plastic; common very fine, few fine and coarse roots; common very fine tubular pores; few thin clay films on peds faces; 35 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (0 to 30 cm thick)

Bt2--20 to 41 cm; pale brown (10YR 6/3) very gravelly clay, brown (10YR 4/3) moist; moderate medium prismatic structure parting to strong medium and coarse subangular blocky; hard, firm, very sticky and very plastic; few very fine and medium roots; common very fine tubular pores; common moderately thick clay films on peds and lining pores; 40 percent gravel; neutral (pH 7.0); clear wavy boundary. (15 to 38 cm thick)

Bt3--41 to 56 cm; light yellowish brown (10YR 6/4) very gravelly sandy clay, yellowish brown (10YR 5/4) moist; moderate fine and medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few very fine and fine roots; common very fine tubular and few very fine interstitial pores; common moderately thick clay films on ped faces, and lining pores, and bridging sand grains; thin coats of carbonates on undersides of gravel; 40 percent gravel; slightly alkaline (pH 7.4); clear wavy boundary. (0 to 33 cm thick)

2Bk--56 to 127 cm; very pale brown (10YR 7/3) extremely gravelly loamy sand, yellowish brown (10YR 5/4) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine and fine roots; many very fine interstitial pores, many moderately thick lime coats on gravel; 75 percent gravel; violently effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (10 to 76 cm thick)

2Bqk--127 to 152 cm; very pale brown (10YR 8/2) extremely gravelly loamy sand, pale brown (10YR 6/3) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine roots, many very fine interstitial pores; continuous brittle matrix many moderately thick lime coats on gravel; 75 percent gravel; violently effervescent; moderately alkaline (pH 8.4).

TYPE LOCATION: Elko County, Nevada; approximately 32 miles north of Elko, about 1,300 feet south and 2,100 feet west of the northeast corner, Sec. 18, T. 38 N., R. 58 E.; latitude 41 degrees 11 minutes 11 seconds N and longitude 115 degrees 28 minutes 38 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Moist in winter and spring, dry June through October; aridic soil moisture regime bordering on xeric.
Mean annual soil temperature: 8 to 11 degrees C.
Combined thickness of A and Bt horizons: 50 to 100 cm.
Depth to carbonates: 50 to 100 cm.
Depth to silica cementation: 100 to over 152 cm.
Reaction: Neutral through moderately alkaline, normally increasing with depth.
Other features: Transitional A/B or E/B horizons are in some pedons.

Particle-size control section - Clay content: 35 to 50 percent.
Rock fragments: 35 to 60 percent, mainly gravel with up to 20 percent cobbles in some pedons.

A horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3.

Bt horizon
Hue: 7.5YR or 10YR.
Value: 5 or 6 dry, 3 through 5 moist.
Chroma: 2 through 4.
Texture: Very gravelly clay, very gravelly sandy clay, very gravelly sandy clay loam, very gravelly clay loam or extremely gravelly sandy clay.
Structure: Prismatic, subangular or angular blocky or is massive in the lower part.
Consistence: Slightly hard to very hard dry; friable to very firm moist; sticky or very sticky and plastic or very plastic, wet.

2Bk or 2Bqk horizons
Value: 5 through 8 dry, 4 through 6 moist.
Chroma: 2 through 4.
Texture: Extremely gravelly loamy sand or very gravelly sandy loam.
Rock fragments: 35 to 75 percent, mainly gravel.
Other features: Some pedons lack 40 to 50 percent discontinuous silica cementation in the lower subhorizon.
Consistence: Loose to slightly hard, dry; loose to firm, moist.

COMPETING SERIES: These are the Berning, Clenage, Havingdon, Lambranch, Maderbak, Pula, Surgem, Tanawit, Tenmile, Vanwyper and Zephan series.

Berning soils have 100 to more than 150 cm thick solums and lack Bk horizons. Clenage, Havingdon, Maderbak, Surgem and Vanwyper soils are moderately deep to a lithic contact. Lambranch and Pula soils lack carbonates in their profile. Tanawit soils a 2C horizon with sandy loam, silt loam or loam derived from thinly stratified sedimentary deposits. Tenmile soils have mean annual soil temperatures of 11 to 13 degrees C, and lack carbonates within 50 to 100 cm. Zephan soils have a lithic contact at 100 to 150 cm.

GEOGRAPHIC SETTING: Bilbo soils are on sideslopes of fan piedmont remnants, hills, partial ballenas, plateaus and some inset fan remnants. They formed in alluvium derived from mixed rocks and in some areas in colluvium from shale, sandstone or conglomerate. Elevations are 1,465 to 2,135 meters. Slopes are 2 to 75 percent. The climate is cool, semiarid with moist winters and dry summers. The mean annual precipitation is 200 to 250 mm; mean annual temperature is 7 to 9 degrees C, and frost-free season is 80 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Donna, Gance, Lyra, McIvery, Stampede and Wieland soils. McIvery soils have mollic epipedons. Donna and Stampede soils have mollic epipedons and are moderately deep to a indurated duripan. Gance and Wieland soils have durinodes within 100 cm. Lyra soils are shallow to a paralithic contact.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium to very rapid runoff; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: Livestock grazing and wildlife habitat. The present vegetation is mainly Wyoming big sagebrush, Douglas rabbitbrush, Sandberg bluegrass and bluebunch wheatgrass.

DISTRIBUTION AND EXTENT: Northeastern Nevada. MLRA 25. These soils are moderately extensive.

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

SERIES ESTABLISHED: Elko County, Nevada, central part, 1986.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 10 cm (A1, A2 horizons).
Xeric Intergrades - Soil moisture regime and organic carbon content meets the requirement for xeric.
Argillic horizon - The zone from 10 to 56 cm (Bt1, Bt2, Bt3 horizons).
Particle-size control section - The zone from 10 to 56 cm (Bt1, Bt2, Bt3 horizons).

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National Cooperative Soil Survey
U.S.A.