LOCATION DUNNLAKE                CA

Established Series
Rev. SJB-DJE-JVC
07/2011

DUNNLAKE SERIES

The Dunnlake series consists of shallow, well drained soils that formed in eolian material and residuum weathered from basalt or andesite. Dunnlake soils are on lava plateaus and mountains. Slopes are 0 to 50 percent. The mean annual precipitation is about 10 inches and the annual temperature is about 46 degrees F.

TAXONOMIC CLASS: Clayey, smectitic, mesic Aridic Lithic Argixerolls

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

A--0 to 4 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate medium platy structure parting to moderate medium granular; soft, very friable, slightly sticky and slightly plastic; many very fine and many fine roots; common very fine interstitial pores; 5 percent cobbles and 5 percent pebbles; neutral; abrupt smooth boundary. (3 to 5 inches thick)

Bt1--4 to 7 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; many very fine and many fine roots; many very fine interstitial pores; few distinct clay films on faces of peds; 5 percent cobbles and 5 percent pebbles; neutral; clear smooth boundary. (2 to 4 inches thick)

Bt2--7 to 10 inches; brown (10YR 5/3) clay, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common fine and few medium roots; many very fine interstitial pores; common distinct clay films on faces of peds; 5 percent cobbles and 5 percent pebbles; neutral; clear smooth boundary. (2 to 4 inches thick)

Bt3--10 to 16 inches; yellowish brown (10YR 5/4) clay, dark yellowish brown (10YR 4/4) moist; strong fine subangular blocky structure; hard, firm, very sticky and very plastic; common fine and few medium roots; many very fine interstitial pores; many distinct clay films on faces of peds; 3 percent cobbles and 5 percent pebbles; neutral; abrupt smooth boundary. (3 to 6 inches thick)

R--16 inches; hard, unweathered basalt.

TYPE LOCATION: Siskiyou County, California; on Little Tableland about 2 miles southwest of Lower Klamath Lake; about 2,532 feet north and 2,321 feet west of the southeast corner of section 3, T. 46 N., R. 2 E.; USGS Mount Dome 7.5 minute topographic quadrangle; 41 degrees 51 minutes 26 seconds north latitude and 121 degrees 43 minutes 56 seconds west longitude, NAD27.

RANGE IN CHARACTERISTICS:

Soil moisture - The soil is dry in all parts of the moisture control section from June 1 to November 15 and moist in all parts from December 15 to April 15. The soil temperature exceeds 41 degrees F from April 1 to December 15 and exceeds 47 degrees F from May 1 to November 15; aridic moisture regime that borders on xeric.

Mean annual soil temperature - 47 to 53 degrees F.

Mollic epipedon thickness - 7 to 12 inches; includes the Bt1 and Bt2 horizons.

Depth to base of argillic horizon - 12 to 20 inches.

Depth to bedrock - 12 to 20 inches to a lithic contact.

Particle-size control section - Clay content: Averages 35 to 50 percent; Rock fragments: Averages 3 to 27 percent, mainly medium and coarse gravel. Lithology of fragments are volcanic rocks such as basalt or andesite.


A horizon - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Clay content: 18 to 27 percent.
Organic matter content: 1 or 2 percent.
Reaction: Slightly acid or neutral.


Bt1 horizon - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Clay loam or gravelly clay loam.
Clay content: 27 to 35 percent.
Rock fragments: 3 to 27 percent.
Organic matter content: 1 or 2 percent.
Reaction: Slightly acid or neutral.


Bt2 horizon - Texture: Clay, clay loam, gravelly clay, or gravelly clay loam.
Clay content: 35 to 50 percent.
Rock fragments: 3 to 30 percent.
Organic matter content: 1 or 2 percent.
Reaction: Neutral or slightly alkaline.


Bt3 horizon - Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 4 through 6, dry or moist.
Texture: Clay, clay loam, gravelly clay, or gravelly clay loam.
Clay content: 35 to 50 percent.
Rock fragments: 3 to 30 percent.
Reaction: Neutral or slightly alkaline.

COMPETING SERIES: These are the Bidrim, Brezniak, Cullius, Devada, and Wylo series.

Bidrim soils have A horizons with 3 to 8 percent organic matter and have subhorizons of the argillic horizon with slickensides and 55 to 65 percent clay. Brezniak soils are 7 to 12 inches to the lithic contact. Cullius soils are influenced by pumiceous volcanic ash in the surface horizons. Devada soils have an abrupt clay increase of 20 percent between the A and B horizons. Wylo soils have mean annual soil temperature of 54 to 59 degrees F.

GEOGRAPHIC SETTING: Dunnlake series are on lava plateaus and mountains. They occur on all slope positions, but on backslope positions they are mainly on south-facing aspects. These soils formed in eolian material and residuum weathered from basalt or andesite. Slopes are 0 to 50 percent. Elevations range from 4,100 to 4,800 feet. The climate is semiarid with cold, moist winters and warm, dry summers. The mean annual precipitation is 8 to 12 inches. The mean January temperature is 26 to 32 degrees F. and the mean July temperature is 62 to 67 degrees F. The mean annual temperature is 44 to 50 degrees F. The frost-free period is 60 to 80 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bucklake, Lequieu, Rangee, and Searles soils. Bucklake soils are moderately deep to lithic contacts. Lequieu soils are loamy-skeletal, very shallow to lithic contacts, and do not have diagnostic subsurface horizons. Rangee soils are very-fine, moderately deep to thin duripans over lithic contacts, and have an abrupt increase in clay in the argillic horizon. Searles soils are loamy-skeletal and are moderately deep to lithic contacts.

DRAINAGE AND PERMEABILITY: Well drained; very high surface runoff; slow permeability.

USE AND VEGETATION: Dunnlake soils are used for rangeland. The vegetation is mainly bluebunch wheatgrass, Thurber's needlegrass, and low sagebrush. Scattered western juniper trees occur in some areas.

DISTRIBUTION AND EXTENT: Northern California. These soils are moderately extensive. MLRA 21.

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

SERIES ESTABLISHED: Siskiyou County (Butte Valley-Tule Lake Area), California, 1986.

REMARKS: This revision of February 2003 moves the type location from Lassen County to Siskiyou County, California, to a soil survey area where the series is correlated. Although the Dunnlake series was proposed in the Susanville Area soil survey in 1985, it was eventually correlated to the competing Devada series.

Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon - The zone from the soil surface to 10 inches (A, Bt1, and Bt2 horizons).

Argillic horizon - The zone from 4 to 16 inches (Bt1, Bt2, and Bt3 horizons).

Lithic contact - The boundary at 16 inches to hard, unweathered bedrock (R layer).

Particle-size control section - The zone from 4 to 16 inches (Bt1, Bt2, and Bt3 horizons).

Classification was updated to 11th edition on 07/2011 changed from Lithic Argixerolls to Aridic Lithic Argixerolls

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National Cooperative Soil Survey
U.S.A.