LOCATION GOLSUM                  NV

Established Series
Rev. JVC/JBF
03/2016

GOLSUM SERIES

The Golsum series consists of moderately deep, well drained soils that formed in residuum and colluvium derived from mixed rocks. Golsum soils are on rock pediments, hills, and mountains. Slopes are 4 to 50 percent. The mean annual precipitation is about 280 mm and the mean annual temperature is about 7 degrees C.

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

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

A1--0 to 8 cm; brown (10YR 5/3) very cobbly loam, dark brown (10YR 3/3) moist; moderate very fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine and fine interstitial and common very fine tubular pores; 20 percent gravel, 15 percent cobbles, and 2 percent stones; neutral (pH 7.0); clear smooth boundary. (5 to 15 cm thick)

A2--8 to 23 cm; brown (10YR 5/3) gravelly loam, dark brown (10YR 3/3) moist; weak fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; many very fine interstitial and common very fine tubular pores; 20 percent gravel; neutral (pH 7.0); clear smooth boundary. (0 to 20 cm thick)

Bt1--23 to 41 cm; brown (10YR 5/3) very gravelly clay, dark brown (10YR 3/3) moist; weak very fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; common very fine, fine and medium roots; few very fine interstitial and common very fine and fine tubular pores; common distinct clay films on faces of peds and lining pores; 35 percent gravel; neutral (pH 7.2); abrupt wavy boundary. (10 to 20 cm thick)

Bt2--41 to 61 cm; yellowish brown (10YR 5/4) very gravelly clay, dark yellowish brown (10YR 4/4) moist; moderate very fine subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few very fine roots; common very fine tubular pores; many distinct and few prominent clay films on faces of peds and lining pores; 50 percent gravel; neutral (pH 7.2); abrupt wavy boundary. (10 to 25 cm thick)

Btk--61 to 79 cm; pale brown (10YR 6/3) very gravelly loam, brown (10YR 4/3) moist; weak fine angular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; common fine interstitial pores; common distinct clay films on faces of peds and lining pores; 50 percent gravel; secondary carbonates segregated as masses and seams; slightly effervescent matrix and strongly effervescent masses; strongly alkaline (pH 8.6); abrupt irregular boundary. (10 to 25 cm thick)

Cr--79 to 86 cm; yellowish brown (10YR 5/4) weathered bedrock, dark yellowish brown (10YR 4/4) moist; massive, rock structure evident; very hard, firm.

TYPE LOCATION: Humboldt County, Nevada; approximately 4 miles southeast of Winnemucca in Water Canyon; about 1,400 feet south of the northeast corner of section 11, T. 35 N., R. 38 E.; USGS Winnemucca East 7.5 minute topographic quadrangle; latitude 40 degrees 55 minutes 33 seconds N and longitude 117 degrees 39 minutes 41 seconds W; WGS84 Decimal Degrees 40.9258333 latitude, -117.6613889 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry late June through October; aridic soil moisture regime that borders on xeric.
Mean annual soil temperature: 6 to 8 degrees C.
Mollic epipedon thickness: 25 to 40 cm, includes the Bt1 horizon.
Depth to identifiable secondary carbonates: 38 to 76 cm.
Depth to bedrock: 50 to 100 cm to a paralithic contact.

Particle-size control section - Clay content: Averages 35 to 45 percent.
Rock fragments: Averages 35 to 55 percent, mainly gravel. Lithology of fragments is mixed rocks.

A horizons
Value: 4 or 5 dry.
Chroma: 2 or 3, dry or moist.
Organic matter content: 2 to 4 percent.

Bt1 and Bt2 horizons
Hue: 10YR or 7.5YR.
Value: 4 through 6 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Very gravelly clay loam, very gravelly clay, or very cobbly clay; thin subhorizons of gravelly clay are in some pedons.
Structure: Subangular blocky, angular blocky, prismatic, or it is massive in some subhorizons.
Reaction: Neutral or slightly alkaline.
Organic matter content: 1 or 2 percent in the Bt1 horizon.

Btk horizon
Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 3 through 5 moist.
Chroma: 2 through 4, dry or moist.
Clay content: 18 to 30 percent
Texture: Very gravelly loam or very gravelly clay loam.
Structure: Weak to strong, subangular blocky or angular blocky.
Reaction: Moderately alkaline or strongly alkaline.

COMPETING SERIES: These are the Carstump and Cronks series.

Carstump soils are moderately deep to lithic contacts. Cronks soils are very deep.

GEOGRAPHIC SETTING: Golsum soils are rock pediments, hills, and mountains. These soils formed in residuum and colluvium derived from mixed rocks. Slopes are 4 to 50 percent. Elevations range from 6,000 to 9,000 feet. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 250 to 360 mm, mean annual temperature is 4 to 7 degrees C, and the frost-free period is 70 to 90 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Graley, Pernty, and Sumine soils. Graley soils are shallow to lithic contacts. Pernty soils are loamy-skeletal and shallow to lithic contacts. Sumine soils are loamy-skeletal and moderately deep to lithic contacts.

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

USE AND VEGETATION: Golsum soils are used rangeland and wildlife habitat. The present vegetation is mainly mountain big sagebrush, rabbitbrush, bottlebrush squirreltail, Idaho fescue, Sandberg's bluegrass, Thurber's needlegrass, phlox, balsamroot, hawksbeard, buckwheat, daisy, and penstemon.

DISTRIBUTION AND EXTENT: Northern Nevada. These soils are moderately extensive. The series concept and main acreage is in MLRA 24, while other acreage occurs in MLRA 25.

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

SERIES ESTABLISHED: Humboldt County, Nevada (BLM Sonoma Planning Unit), 1974.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 41 cm (A1, A2, and Bt1 horizons).
Argillic horizon - The zone from 23 to 79 cm (Bt1, Bt2, and Btk horizons).
Identifiable secondary carbonates - The zone from 61 to 79 cm (Btk horizon).
Paralithic contact - The boundary at 79 cm to underlying weathered bedrock (Cr layer).
Particle-size control section - The zone from 23 to 73 cm (Bt1 and Bt2 horizons and part of the Btk horizon).

ADDITIONAL DATA: Previous authors and editors include: ELS-DD-RLB.

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National Cooperative Soil Survey
U.S.A.