LOCATION DRAKESFLAT OR
Established Series
Rev. JVC-JBF
02/2011
DRAKESFLAT SERIES
The Drakesflat series consists of moderately deep, well drained soils that formed in colluvium and residuum derived from basalt and tuff. Drakesflat soils are on lava plateaus. Slopes are 2 to 30 percent. The mean annual precipitation is about 280 mm and the mean annual temperature is 6 degrees C.
TAXONOMIC CLASS: Fine, smectitic, frigid Calciargidic Argixerolls
TYPICAL PEDON: Drakesflat loam--rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 15 cm; very dark grayish brown (10YR 3/2) loam, very dark brown (10YR 2/2) moist; moderate fine and medium subangular blocky structure; soft, very friable, slightly sticky and nonplastic; many fine and coarse roots; 5 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary. (5 to 15 cm thick)
A2--15 to 30 cm; dark brown (10YR 3/3) cobbly loam, very dark grayish brown (10YR 3/2) moist; strong fine and medium angular blocky structure; soft, friable, slightly sticky and nonplastic; common medium and coarse roots; 10 percent gravel and 10 percent cobbles; slightly alkaline (pH 7.4); abrupt smooth boundary. (3 to 20 cm thick)
2Bt--30 to 58 cm; dark yellowish brown (10YR 3/4) clay loam, dark brown (10YR 3/3) moist; strong fine prismatic structure; hard, firm, moderately sticky and slightly plastic; common fine and medium roots; 10 percent fine gravel; many distinct clay films on faces of peds; slightly alkaline (pH 7.6); gradual wavy boundary. (20 to 40 cm thick)
2Bk--58 to 79 cm; brown (7.5YR 5/4) clay loam, brown (10YR 4/3) moist; massive; slightly hard, firm, slightly sticky and slightly plastic; few fine roots; 5 percent fine gravel; slightly effervescent; secondary carbonates segregated in few irregular seams and filaments; moderately alkaline (pH 8.0); abrupt irregular boundary. (13 to 43 cm thick)
3R---79 cm; tuff with coatings of silica and calcium carbonate in fractures.
TYPE LOCATION: Lake County, Oregon; between Deppy Creek and McDowell Creek; in the NW 1/4 of the SW 1/4 of the NW 1/4 of section 5, T. 37 S., R. 23 E.; USGS Drake Peak NE 7.5 minute topographic quadrangle; latitude 42 degrees 23 minutes 29 seconds N and longitude 120 degrees 2 minutes 30 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: 7 to 8 degrees C.
Mollic epipedon thickness: 18 to 30 cm; includes only the A horizons.
Depth to horizon with identifiable secondary carbonates: 38 to 76 cm.
Depth to bedrock: 50 to 100 cm to a lithic contact.
Particle-size control section - Clay content: 35 to 45 percent.
Rock fragments: Averages 5 to 20 percent, mainly cobbles. Lithology of fragments are volcanic rocks such as basalt or tuff.
A 1 horizon
Value: 3 through 5 dry, 2 or 3 moist; some pedons have an A1 horizon with dry value of 6, but the upper 18 cm mixed has dry value of 5.
Chroma: 2 or 3, dry or moist.
Reaction: Neutral through moderately alkaline.
Organic matter content: 1 to 4 percent.
A2 horizon
Value: 3 through 5 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist.
Rock fragments: 5 to 20 percent gravel, 0 to 20 percent cobbles, and 0 to 10 percent stones.
Reaction: Neutral through moderately alkaline.
Organic matter content: 1 to 4 percent.
2Bt horizon
Hue: 7.5YR or 10YR.
Value: 3 through 6 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Clay loam, cobbly clay loam, cobbly clay or clay.
Clay content: 35 to 45 percent.
Rock fragments: 5 to 15 percent gravel, 0 to 15 percent cobbles, and 0 to 5 percent stones.
Reaction: Slightly alkaline or moderately alkaline.
2Bk horizon
Hue: 7.5YR or 10YR.
Value: 3 through 5 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Clay loam, cobbly clay loam, gravelly loam, or cobbly loam.
Clay content: 25 to 40 percent.
Rock fragments: 0 to 30 percent gravel, 0 to 15 percent cobbles, and 0 to 5 percent stones.
Reaction: Moderately alkaline or strongly alkaline.
Effervescence: Slightly effervescent or strongly effervescent.
Calcium carbonate equivalent: 2 to 8 percent.
COMPETING SERIES: These are the
Marack and
Ramires series.
Marack soils are deep to paralithic contacts.
Ramires soils have mollic epipedons that include the upper part of the argillic horizon and have a Bk horizon with texture of sandy loam or sandy clay loam.
GEOGRAPHIC SETTING: Drakesflat soils are on lava plateaus. These soils formed in colluvium and residuum derived from basalt and tuff. Slopes are 2 to 30 percent. Elevations range from 1,359 to 1,800 meters. The climate is semiarid and characterized by cold, moist winters and warm, dry summers. The mean annual precipitation is 250 to 300 mm, the mean annual temperature is 4 to 7 degrees C, and the frost-free period is 50 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Coglin and
Fertaline soils. Coglin soils are deep. Fertaline soils are moderately deep to duripans.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high surface runoff; slow permeability; moderately low saturated hydraulic conductivity.
USE AND VEGETATION: Drakesflat soils are used for livestock grazing and wildlife habitat. The native vegetation is Wyoming big sagebrush, bluebunch wheatgrass, and Thurber's needlegrass.
DISTRIBUTION AND EXTENT: South-central Oregon. These soils are not extensive. MLRA 23.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Lake County (Southern Part), Oregon, 1991.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 30 cm (A1 and A2 horizons).
Argillic horizon - The zone from 30 to 58 cm (2Bt horizon).
Identifiable secondary carbonates - The zone from 58 to 79 cm (2Bk horizon).
Lithic contact - The boundary at 79 cm to underlying hard, unweathered bedrock (3R layer).
Particle-size control section - The zone from 30 to 58 cm (2Bt horizon).
ADDITIONAL DATA: Previous authors and editors include: AJM-RJK-TDT.
National Cooperative Soil Survey
U.S.A.