LOCATION GLASSBUTTE              OR

Established Series
Rev. CWL-MPK-JVC-JBF
03/2011

GLASSBUTTE SERIES

The Glassbutte series consists of very deep, well drained soils that formed in volcanic ash and colluvium over residuum derived from rhyolite. Glassbutte soils are on hills and mountains. Slopes are 20 to 65 percent. The mean annual precipitation is about 300 mm and the mean annual temperature is about 6 degrees C.

TAXONOMIC CLASS: Ashy-skeletal, glassy, frigid Vitritorrandic Argixerolls

TYPICAL PEDON: Glassbutte gravelly ashy fine sandy loam--on a hill sloping 30 percent to the north at an elevation of 1,542 meters--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 10 cm; grayish brown (10YR 5/2) gravelly ashy fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak fine platy structure parting to moderate medium granular; soft, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; common very fine, common fine, few medium tubular and interstitial pores; 20 percent gravel and 5 percent cobbles; neutral (pH 7.0); clear smooth boundary. (8 to 15 cm thick)

A2--10 to 30 cm; brown (10YR 5/3) gravelly ashy fine sandy loam, dark brown (10YR 3/3) moist; strong medium granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine, common fine, and few medium roots; common fine interstitial and few fine tubular pores; 25 percent gravel and 5 percent cobbles; neutral (pH 7.0); clear smooth boundary. (15 to 20 cm thick)

Bt--30 to 58 cm; yellowish brown (10YR 5/4) extremely gravelly ashy sandy clay loam, dark brown (10YR 3/3) moist; moderate medium granular structure; soft, very friable, moderately sticky and slightly plastic; soft, very friable, moderately sticky and slightly plastic; common very fine and few fine roots; common very fine, many fine, few medium interstitial and tubular pores; few faint clay films bridging sand grains; 50 percent gravel and 15 percent cobbles; slightly alkaline (pH 7.4); gradual smooth boundary. (23 to 30 cm thick)

2Bk--58 to 117 cm; pale brown (10YR 6/3) extremely cobbly ashy loamy coarse sand, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; common very fine and few fine roots; common fine, few medium tubular and interstitial pores; 40 percent gravel and 35 percent cobbles; secondary calcium carbonates segregated as many thin (<1 mm) coats on rock fragments and as few fine masses throughout the matrix; strongly effervescent; slightly alkaline (pH 7.8); gradual smooth boundary. (15 to 58 cm thick)

2Ck--117 to 155 cm; very pale brown (10YR 7/4) extremely cobbly ashy loamy sand, yellowish brown (10YR 5/4) moist; single grain; loose, nonsticky and nonplastic; few very fine and few fine roots; common fine interstitial pores; 40 percent gravel and 40 percent cobbles; secondary calcium carbonates segregated as few medium and coarse coats on bottoms of rock fragments; strongly effervescent; slightly alkaline (pH 7.8).

TYPE LOCATION: Lake County, Oregon; in the eastern Glass Buttes about 0.5 mile south of Wise Flat; approximately 600 feet south and 2,100 feet west of the northeast corner of section 34, T. 23 S., R. 23 E.; USGS Hat Butte 7.5 minute topographic quadrangle; latitude 43 degrees 32 minutes 25 seconds N and longitude 119 degrees 56 minutes 34 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in winter and spring, dry in summer and fall; aridic moisture regime that borders on xeric.
Mean annual soil temperature: 6 to 8 degrees C.
Mollic epipedon thickness; 50 to 76 cm; includes the Bt horizon in some pedons.
Depth to identifiable secondary carbonates: 50 to 100 cm.
Volcanic glass content: 60 to 90 percent in coarse silt through fine sand fractions.

Particle-size control section - Clay content: 20 to 30 percent;
Rock fragments: 60 to 85 percent, mainly gravel. Lithology of fragments are volcanic rocks such as rhyolite or rhyodacite.

A1 horizon
Chroma: 2 or 3, dry or moist.
Reaction: Neutral or slightly alkaline.
Organic matter content: 2 to 4 percent.

A2 horizon
Texture: Gravelly ashy fine sandy loam, gravelly ashy loam, or very gravelly ashy loam.
Clay content: 15 to 25 percent.
Rock fragments: 20 to 55 percent.
Reaction: Neutral or slightly alkaline.
Organic matter content: 2 to 4 percent.

Bt horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Extremely gravelly ashy sandy clay loam or extremely cobbly clay loam.
Clay content: 20 to 30 percent.
Rock fragments: 60 to 80 percent.
Reaction: Neutral or slightly alkaline.
Organic matter content: 1 to 3 percent.
2Bk horizon

Calcium carbonate equivalent: 1 to 3 percent.
2Ck horizon
Value: 6 or 7 dry, 4 or 5 moist.
Texture: Extremely cobbly ashy loamy sand or extremely cobbly ashy sandy loam.
Clay content: 6 to 18 percent.
Rock fragments: 60 to 80 percent.
Reaction: Slightly alkaline or moderately alkaline.
Calcium carbonate equivalent: 1 to 3 percent.

COMPETING SERIES: These are the Cabinspring, Cagas, Derallo, Jacksplace, Roughridge , and Slockey series.

Cabinspring, Jacksplace, and Slockey soils are moderately deep to lithic contacts. Cagas soils are moderately deep to paralithic contacts. Derallo soils are deep to paralithic contacts. Roughridge soils have 12 to 18 percent clay in the particle-size control section and secondary silica cementation at a depth of 40 to 60 cm.

GEOGRAPHIC SETTING: Glassbutte soils are on hills and mountains. They typically occur on backslope positions. These soils formed in volcanic ash and colluvium over residuum derived from volcanic rocks such as rhyolite or rhyodacite. Slopes are 20 to 65 percent. Elevations range from 1,415 to 1,895 meters. The climate is semiarid with cool, moist winters and warm, dry summers. The mean annual precipitation is 250 to 360 meters, the mean annual temperature is 4 to 7 degrees C, and the frost-free period is 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: This is the Lambring soil. Lambring soils do not have argillic horizons.

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

USE AND VEGETATION: Glassbutte soils are used for livestock grazing and wildlife habitat. The vegetation is low sagebrush, Idaho fescue, and bluebunch wheatgrass. Areas where these soils occur are adjacent to mineral claims where cinnabar (Mercury sulfide ore) was mined.

DISTRIBUTION AND EXTENT: South-central Oregon. These soils are not extensive with about 1,400 acres of the series mapped to date. MLRA 23.

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

SERIES ESTABLISHED: Lake County (Northern Part), Oregon, 2006.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 58 cm (A1, A2, and Bt horizons).
Argillic horizon - The zone from 30 to 58 cm (Bt horizon).
Vitrandic intergrade feature - The zone from the soil surface to 76 cm (A1, A2, and Bt horizons and part of the 2Bk horizon).
Identifiable secondary carbonates - The zone from 58 to 155 cm (2Bk and 2Ck horizons).
Particle-size control section and ashy-skeletal substitute class with glassy mineralogy - The zone from 30 to 58 cm (Bt horizon).

ADDITIONAL DATA: Volcanic glass content determined locally by optical grain counts using a polarizing petrographic microscope.

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National Cooperative Soil Survey
U.S.A.