LOCATION DEVEN CA+ID NV

Established Series
Rev. WBS/GMK/TDC/JBF
03/2017

DEVEN SERIES

The Deven series consists of shallow, well drained soils that formed in residuum and colluvium derived from basalt, andesite and tuff. The Deven soils are on plateaus and have slopes of 0 to 50 percent. The mean annual precipitation is about 300 mm and the mean annual temperature is about 8 degrees C.

TAXONOMIC CLASS: Clayey, smectitic, mesic Lithic Argixerolls

TYPICAL PEDON: Deven loam on a 1 percent slope under western juniper, bitterbrush, cheatgrass and squawapple at 1,500 meters elevation. (Colors are for dry soil unless otherwise stated. When described (8/24/73) the soil was dry throughout.)

A--0 to 5 cm; brown (10YR 5/3) loam, dark brown (7.5YR 3/2) moist; moderate fine granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; many very fine interstitial pores; slightly acid (pH 6.3); clear smooth boundary. (3 to 15 cm thick)

Bt1--5 to 18 cm; brown (7.5YR 4/2) clay loam, dark brown (7.5YR 3/2) moist; moderate medium and coarse subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; common very fine, fine and medium roots; common very fine tubular and few very fine interstitial pores; many distinct clay films on faces of peds and in pores; slightly acid (pH 6.5); clear wavy boundary. (5 to 13 cm thick)

Bt2--18 to 41 cm; dark reddish brown (5YR 3/4) clay, dark reddish brown (5YR 3/2) moist; moderate medium and coarse angular blocky structure; hard, very friable, moderately sticky and moderately plastic; few very fine, common fine and medium roots; few very fine tubular and interstitial pores; continuous distinct clay films on faces of peds and in pores; slightly acid (pH 6.5); abrupt irregular boundary. (18 to 33 cm thick)

R--41 to 61 cm; gray (N 5/) hard fractured basalt.

TYPE LOCATION: Modoc County, California; about 5 miles northwest of Alturas; about 0.75 mile south on Croder Flat Road from the Modoc National Forest boundary and 75 feet east of the road in the northeast 1/4 southwest 1/4 corner of section 6, T. 42 N., R. 12 E.; USGS Big Sage Reservoir 7.5 minute topographic quadrangle; latitude 41 degrees 30 minutes 18 seconds N and longitude 120 degrees 38 minutes 05 seconds W; WGS84 Decimal Degrees 41.5050000 latitude, -120.6347222 longitude.

RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry in all parts from June 1 until October 30 and is moist in some or all parts the rest of the year; xeric soil moisture regime bordering on aridic.
Mean annual soil temperature: 8 to 13 degrees C.
Depth to a lithic contact of hard fractured basalt: 25 to 50 cm.
Reaction: Slightly acid through slightly alkaline.

Particle-size control section - Clay content: 35 to 50 percent.
Rock fragments: Average less than 15 percent. Increase with depth and make up to 25 percent of the volume and are most common in the lower part. These fragments consist of basalt gravel, cobblestones and stones.

A horizon
Hue: 10YR or 7.5YR.
Value: 4 or 5 dry, 2 or 3 moist.
Hue 2 or 3.
Structure: Weak or moderate very fine to medium platy subangular blocky or granular structure.

Bt horizon
Hue 10YR or 7.5YR.
Value: 3 through 5 dry, 3 or 4 moist.
Chroma: 2 through 4.
Texture: Clay loam or clay with and has at least 8 percent more clay than the A horizon.
Structure: Angular blocky or prismatic structure.
Other features: Some pedons have a Bt2 horizon, a transitional Bt3 horizon or a C horizon. These are similar to the Bt horizon but commonly have subangular blocky structure or are massive. The soil fills the space between the fractures in the bedrock and is in pockets. Some pedons have a very thin discontinuous coating of carbonate and silica capping the bedrock.

COMPETING SERIES: This is the Devnot series.
Devnot soils average 15 to 35 percent rock fragments in the particle-size control section.

GEOGRAPHIC SETTING: Deven soils are on hummocky plateaus and plateau escarpments. Slopes are 0 to 50 percent. The soils formed in residuum and colluvium derived from basalt, andesite and hard tuff. Elevations are 1,070 to 1,985 meters. Deven soils are commonly in association or complex with rock outcrop. The climate is cool semiarid mesothermal with warm dry summers and cold moist winters. Mean annual precipitation is 250 to 460 mm. Seasonal snowfall is 60 to 120 cm. Mean annual temperature is 7 to 9 degrees C. Frost-free season is 70 to 130 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ditchcamp, Karcal, and Packwood soils Ditchcamp and Packwood soils have a fine-loamy control section and have a duripan at a depth. Karcal soils have cracks that extend to the surface.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; slow to rapid runoff; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: Used mainly for rangeland and as habitat for wildlife. Vegetation is western juniper, bitterbrush, low sagebrush, squawapple, Sandberg bluegrass, needlegrass, Bottlebrush squirreltail, cheatgrass and mustard.
DISTRIBUTION AND EXTENT: Northeastern California in Modoc County. The soils are moderately extensive. MLRA 21.

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

SERIES ESTABLISHED: Modoc County (Alturas Area), California, 1974.

REMARKS: Deven soils were originally mapped as Madeline series. During the correlation of Surprise Valley-Home Camp Soil Survey, Madeline soils were found to have frigid temperature regimes.

Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 18 cm (A and Bti horizons).
Argillic horizon - The zone from 18 to 41 cm (Bt horizon).
Lithic contact - The boundary at 41 cm to underlying hard, unweathered bedrock (R layer).
Particle-size control section - The zone from 18 to 33 cm (Bt1 horizon).

ADDITIONAL DATA: Riverside Laboratory, Pedon S73 Calif 25-10.

National Cooperative Soil Survey
U.S.A.