LOCATION SNAKEPIT                OR

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

SNAKEPIT SERIES

The Snakepit series consists of moderately deep to a duripan, somewhat excessively drained soils that formed in eolian sands and alluvium derived from basalt and welded tuff. Snakepit soils are on depressions of plateaus. Slopes are 0 to 3 percent. The mean annual precipitation is about 280 mm and the mean annual temperature is about 7 degrees C.

TAXONOMIC CLASS: Sandy, mixed, frigid Cambidic Durixerolls

TYPICAL PEDON: Snakepit loamy sand--on a northeast facing slope of 2 percent at an elevation of 1,475 meters--rangeland. (Colors are for dry soil unless otherwise noted.)

A1--0 to 8 cm; brown (10YR 5/3) loamy sand, dark brown (10YR 3/3) moist; single grain; loose, nonsticky and nonplastic; common very fine and few fine roots; common fine and common medium interstitial pores; neutral (pH 7.2); clear smooth boundary. (8 to 13 cm thick)

A2--8 to 28 cm; brown (10YR 5/3) loamy sand, dark brown (10YR 3/3) moist; single grain; loose, nonsticky and nonplastic; common very fine, few fine, and few medium roots; common fine and common medium interstitial and tubular pores; slightly alkaline (pH 7.5); gradual smooth boundary. (13 to 23 cm thick)

A3--28 to 48 cm; brown (10YR 5/3) loamy sand, dark brown (10YR 3/3) moist; single grain; loose, nonsticky and nonplastic; few very fine, few fine, and few medium roots; common fine and common medium interstitial and tubular pores; slightly alkaline (pH 7.8); gradual smooth boundary. (0 to 20 cm thick)

Bw--48 to 76 cm; light brownish gray (10YR 6/2) loamy sand, dark grayish brown (10YR 4/2) moist; weak medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; few very fine, few fine, and few medium roots; common fine and few fine tubular pores; slightly alkaline (pH 7.6); clear smooth boundary. (10 to 36 cm thick)

Bq--76 to 84 cm; light brownish gray (10YR 6/2) sandy loam, dark grayish brown (10YR 4/2) moist; massive; hard, very firm, slightly sticky and nonplastic; few very fine roots; few very fine tubular pores; 40 percent very coarse weakly cemented durinodes; slightly alkaline (pH 7.8); abrupt smooth boundary. (8 to 36 cm thick)

2Bqkm--84 to 107 cm; pale brown (10YR 6/3) cemented material, brown (10YR 4/3) moist; massive; extremely hard, extremely firm; strongly cemented by secondary silica; common laminae of opal, 1 to 3 mm in diameter, in upper part of horizon; about 10 percent gravel and 25 percent cobbles cemented within matrix; strongly effervescent; secondary carbonates segregated as few medium coats on opal laminae; strongly alkaline (pH 8.5); abrupt smooth boundary. (15 to 25 cm thick)

3Bqk--107 to 160 cm; light yellowish brown (10YR 6/4) loamy sand, dark yellowish brown (10YR 4/4) moist; massive; hard, firm and brittle, nonsticky and nonplastic; few fine interstitial pores; 15 percent very coarse weakly cemented durinodes; strongly effervescent; secondary carbonates segregated as few coats on durinodes; strongly alkaline (pH 8.6).

TYPE LOCATION: Lake County, Oregon; along a jeep trail about 0.4 miles south of Sprinkle Waterhole, 1.0 mile north of Sand Hollow, and 3.5 miles southeast of Sharp Top; approximately 300 feet north and 1,200 feet east of the southwest corner of section 12, T. 32 S., R. 19 E.; USGS Sharp Top 7.5 minute topographic quadrangle; latitude 42 degrees 48 minutes 22 seconds N and longitude 120 degrees 25 minutes 50 seconds W; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry in the moisture control section; moist in winter and spring; dry in summer and fall; aridic moisture regime that borders on xeric.
Mean annual soil temperature: 7 to 8 degrees C.
Mollic epipedon thickness: 10 to 19 inches.
Depth to duripan: 50 to 90 cm.
Depth to bedrock: Greater than 150 cm to a lithic contact.

Particle-size control section - Clay content: Averages 4 to 8 percent.
Rock fragments: Averages 0 to 15 percent, mainly gravel. Lithology of fragments are basalt or welded ash-flow tuff.

A1 horizon
Value: 5 or 6 dry, 3 or 4 moist; value is 5 dry and 3 moist when the upper 18 cm of the soil is mixed.
Chroma: 2 or 3, dry or moist.
Structure: Single grain, granular, or platy.
Reaction: Neutral or slightly alkaline.
Organic matter content: 1 to 3 percent.

A2 horizon
Chroma: 2 or 3, dry or moist.
Texture: Loamy sand or cobbly loamy sand.
Clay content: 6 to 8 percent.
Rock fragments: 0 to 20 percent.
Structure: Single grain, granular, or subangular blocky.
Reaction: Slightly alkaline or moderately alkaline.
Organic matter content: 1 to 3 percent.

A3 horizon (when present)
Chroma: 2 or 3, dry or moist.
Texture: Loamy sand or cobbly loamy sand.
Clay content: 6 to 8 percent.
Rock fragments: 0 to 20 percent.
Structure: Single grain, granular, or subangular blocky.
Reaction: Slightly alkaline or moderately alkaline.
Organic matter content: 1 or 2 percent.

Bw horizon
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Texture: Loamy sand or loamy fine sand.
Clay content: 6 to 10 percent.
Rock fragments: 0 to 15 percent, mainly pebbles.
Reaction: Slightly alkaline or moderately alkaline.

Bq horizon or Bqk horizon (when present)
Value: 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Texture: Loamy sand or sandy loam.
Clay content: 8 to 10 percent.
Rock fragments: 0 to 15 percent, mainly gravel.
Structure: Subangular blocky or is massive.
Consistence: Slightly hard or hard dry; some pedons have horizons which are firm and brittle when moist.
Durinodes: 10 to 40 percent very coarse, irregular, weakly cemented or moderately cemented.
Identifiable secondary carbonates: None or occurs as few fine coats on durinodes and faces of peds.
Calcium carbonate equivalent: 0 to 3 percent.
Reaction: Slightly alkaline or moderately alkaline.

2Bqkm horizon
Hue: 7.5YR or 10YR.
Value: 6 through 8 dry, 4 through 6 moist.
Chroma: 3 or 4, dry or moist.
Structure: Platy or is massive.
Cementation: Moderately cemented or strongly cemented by secondary silica.
Identifiable secondary carbonates: Occurs as few fine coats on opal laminae or on bottoms of platy peds.
Reaction: Slightly alkaline or strongly alkaline.
Other features: This horizon is a duripan which has commonly formed in layers of alluvium with 20 to 35 percent rock fragments, mainly gravel and cobbles.

3Bqk horizon
Hue: 7.5YR or 10YR.
Chroma: 2 through 4, dry or moist.
Texture: Loamy sand or sandy loam.
Clay content: 6 to 12 percent.
Rock fragments: 0 to 15 percent, mainly pebbles.
Consistence: Hard, firm and brittle when moist.
Durinodes: 10 to 20 percent very coarse, irregular, weakly cemented or moderately cemented.
Effervescence: Slightly effervescent or strongly effervescent
Identifiable secondary carbonates: Occurs as few or common coats on durinodes or rock fragments.
Calcium carbonate equivalent: 1 to 3 percent.
Reaction: Moderately alkaline or strongly alkaline.

COMPETING SERIES: There are currently no other series in this family.

GEOGRAPHIC SETTING: Snakepit soils are on depressions of plateaus. These soils formed in eolian sands and alluvium derived from basalt and welded tuff. Slopes are 0 to 3 percent. Elevations range from 1,440 to 1,590 meters. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 250 to 300 mm, the mean annual temperature is 6 to 7 degrees C, and the frost-free period is 50 to 70 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Brace, Spiderhole, and Wiskan soils. Brace soils are fine-loamy, moderately deep to thin duripans over lithic contacts, and have ochric epipedons and argillic horizons. Spiderhole soils are loamy-skeletal, shallow to indurated duripans, have ochric epipedons and argillic horizons, and occur on adjacent slopes. Wiskan soils are loamy-skeletal, moderately deep to lithic contacts, have ochric epipedons and argillic horizons, and occur on adjacent hills and escarpments.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively drained; negligible surface runoff; high saturated hydraulic conductivity.

USE AND VEGETATION: Snakepit soils are used for livestock grazing. The vegetation is mainly basin big sagebrush, needleandthread, Thurber's needlegrass, and Indian ricegrass.

DISTRIBUTION AND EXTENT: South-central Oregon. These soils are not extensive with about 2,600 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. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 48 cm (A1, A2, and A3 horizons).
Duripan - The zone from 84 to 107 (2Bqkm horizon).
Particle-size control section - The zone from 25 to 84 cm (A3, Bw, and Bq horizons and part of the A2 horizon).

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National Cooperative Soil Survey
U.S.A.