LOCATION SLIPTRACK               OR

Established Series
Rev. CWL-MPK-JVC-JBF
06/2011

SLIPTRACK SERIES

The Sliptrack series consists of moderately deep to a duripan, well drained soils that formed in volcanic ash and alluvium derived from basalt. Sliptrack soils are on lava plateaus. Slopes are 0 to 8 percent. The mean annual precipitation is about 280 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Ashy, glassy, frigid Vitritorrandic Durixerolls

TYPICAL PEDON: Sliptrack cobbly ashy fine sandy loam--on a lava plateau sloping 2 percent to the north at an elevation of 1,518 meters--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 8 cm; grayish brown (10YR 5/2) cobbly ashy fine sandy loam, very dark grayish brown (10YR 3/2) moist; strong thick platy structure parting to weak fine platy; slightly hard, very friable, slightly sticky and slightly plastic; many very fine and common fine roots; common very fine, common fine, few medium and few coarse vesicular pores; 10 percent gravel, 5 percent cobbles, and 2 percent stones; neutral (pH 6.7); abrupt smooth boundary. (8 to 13 cm thick)

A2--8 to 28 cm; brown (10YR 5/3) ashy fine sandy loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure parting to moderate medium granular; soft, very friable, slightly sticky and slightly plastic; common very fine and fine, few medium roots; common very fine and fine interstitial and tubular pores; neutral (pH 7.0); clear smooth boundary. (10 to 20 cm thick)

Bt1--28 to 41 cm; brown (10YR 5/3) ashy sandy clay loam, dark brown (10YR 3/3) moist; strong medium subangular blocky structure parting to weak fine angular blocky; hard, firm, moderately sticky and moderately plastic; few very fine, few fine, and few medium roots; few very fine and few fine tubular pores; 5 percent gravel and 5 percent cobbles; common faint clay films on faces of peds; slightly alkaline (pH 7.5); clear smooth boundary. (13 to 20 cm thick)

Bt2--41 to 56 cm; yellowish brown (10YR 5/4) ashy clay loam, dark yellowish brown (10YR 3/4) moist; weak medium prismatic structure parting to strong fine and medium angular blocky; hard, firm, moderately sticky and moderately plastic; few very fine and few fine roots; few very fine and few fine tubular pores; 5 percent gravel and 5 percent cobbles; common distinct clay films on faces of peds; slightly alkaline (pH 7.5); abrupt smooth boundary. (10 to 25 cm thick)

Bqm--56 to 74 cm; light yellowish brown (10YR 6/4) cemented material, dark yellowish brown (10YR 3/4) moist; strong medium platy structure; very rigid; indurated by secondary silica; 1 mm. thick opal coats on top of plates and opal pendants on bottoms of peds; abrupt smooth boundary. (0 to 18 cm thick)

Bqkm1--74 to 114 cm; light yellowish brown (10YR 6/4) cemented material, dark yellowish brown (10YR 4/4) moist; strong thick and medium platy structure; rigid; strongly cemented by secondary silica; slightly effervescent; secondary carbonates segregated in threads and disseminated throughout matrix; abrupt smooth boundary. (13 to 40 cm thick)

Bqkm2--114 to 152 cm; very pale brown (10YR 7/3) cemented material, dark yellowish brown (10YR 4/4) moist; moderate medium platy structure; extremely hard, extremely firm; weakly and moderately cemented by secondary silica; slightly effervescent; secondary carbonates segregated in threads and disseminated throughout matrix.

TYPE LOCATION: Lake County, Oregon; about one mile southeast of Saddle Butte; approximately 2,400 feet south and 150 feet west of the northeast corner of section 23, T. 23 S., R. 18 E.; USGS Last Chance Lake 7.5 minute topographic quadrangle; latitude 43 degrees 33 minutes 58 seconds N and longitude 120 degrees 30 minutes 59 seconds W NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually moist in the moisture control section in winter and early spring, dry from late spring through early fall; aridic moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 40 cm; includes the Bt1 horizon in some pedons.
Argillic horizon thickness: 23 to 46 cm.
Depth to duripan; 50 to 100 cm.
Depth to bedrock: 100 to more than 150 cm to a lithic contact.

Particle-size control section - Clay content: 27 to 35 percent.
Rock fragments: 0 to 15 percent, mainly gravel and cobbles. Lithology of fragments is basalt.
Volcanic glass content: 40 to 60 percent in coarse silt through fine sand fractions.

A1 horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Reaction: Neutral or slightly alkaline.
Organic matter content: 2 to 4 percent.

A2 horizon
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist
Clay content: 12 to 18 percent.
Rock fragments: 0 to 15 percent.
Reaction: Neutral or slightly alkaline.
Organic matter content: 2 to 4 percent.

Bt1 horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Clay content: 23 to 35 percent.
Rock fragments: 0 to 15 percent.
Organic matter content: 1 to 3 percent.

Bt2 horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Ashy sandy clay loam or ashy clay loam.
Clay content: 30 to 38 percent.
Rock fragments: 0 to 15 percent.

Bqm, Bqkm1, and Bqkm2 horizons
Cementation: Weakly cemented to indurated; at least one upper subhorizon is very strongly cemented or indurated.

COMPETING SERIES: These are the Greenmountain, Meld, and Milcan series.

Greenmountain soils average 16 to 22 percent clay in the particle-size control section. Meld soils average 20 to 35 percent rock fragments in the particle-size control section. Milcan soils do not have argillic horizons.

GEOGRAPHIC SETTING: Sliptrack soils are in depressions on lava plateaus. These soils formed in volcanic ash and alluvium derived from basalt. Slopes are 0 to 8 percent. Elevations range from 1,405 to 1,555 meters. The climate is semiarid and characterized by cold, moist winters and warm, dry summers. The mean annual precipitation is 230 to 300 mm, the mean annual temperature is 6 to 7 degrees C, and the frost-free period is 50 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Moonbeam and Oatmanflat soils. Moonbeam soils are clayey and shallow to duripans. Oatmanflat soils are deep to buried duripans.

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

USE AND VEGETATION: Sliptrack soils are used for livestock grazing and wildlife habitat. The vegetation is low sagebrush, Idaho fescue, and scattered western juniper.

DISTRIBUTION AND EXTENT: South-central Oregon. These soils are not extensive with about 4,900 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 41 cm (A1, A2, and Bt1 horizons).
Argillic horizon - The zone from 28 to 56 cm (Bt1 and Bt2 horizons).
Vitrandic intergrade feature - The zone from the soil surface to 56 cm (A1, A2, Bt1, and Bt2 horizons).
Duripan - The zone from 56 to 152 cm (Bqm, Bqkm1, and Bqkm2 horizons).
Identifiable secondary carbonates - The zone from 74 to 152 cm (Bqkm1 and Bqkm2 horizons).
Particle-size control section and ashy substitute class with glassy mineralogy - The zone from 28 to 56 cm (Bt1 and Bt2 horizons).

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.