LOCATION DRANKET ORTentative Series
TAXONOMIC CLASS: Fine, smectitic, frigid Typic Durixerolls
TYPICAL PEDON: Dranket very stony loam--on a 1 percent slope at an elevation of 4,960 feet--rangeland. (Colors are for dry soil unless otherwise noted. The soil was moist throughout when it was described on June 17, 1997.) The soil surface is partially covered with about 20 percent pebbles, 20 percent cobbles, and 15 percent stones.
A1--0 to 2 inches; brown (10YR 5/3) very stony loam, dark brown (10YR 3/3) moist; moderate medium platy structure parting to moderate medium granular; slightly hard, friable, slightly sticky and slightly plastic; common very fine and few fine roots; common fine and common medium vesicular pores; 20 percent pebbles, 20 percent cobbles, and 15 percent stones; neutral (pH 7.0); clear smooth boundary. (2 or 3 inches thick)
A2--2 to 8 inches; brown (7.5YR 5/3) very cobbly loam, dark brown (7.5YR 3/3) moist; weak medium subangular blocky structure parting to moderate medium granular; soft, very friable, slightly sticky and slightly plastic; common very fine, common fine, and few medium roots; common fine and common medium tubular pores; 20 percent pebbles, 15 percent cobbles, and 5 percent stones; neutral (pH 7.1); clear smooth boundary. (0 to 6 inches thick)
Bt1--8 to 15 inches; brown (7.5YR 5/4) very cobbly clay loam, dark brown (7.5YR 3/4) moist; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; few very fine, few fine, and common medium roots; common fine and common medium tubular pores; common faint clay films on faces of peds; 15 percent pebbles, 20 percent cobbles, and 5 percent stones; neutral (pH 7.3); abrupt smooth boundary. (4 to 10 inches thick)
Bt2--15 to 23 inches; light brown (7.5YR 6/3) clay, brown (7.5YR 4/3) moist; moderate medium prismatic structure parting to strong medium angular blocky; hard, firm, moderately sticky and very plastic; few very fine, few fine, few medium, few coarse, and few very coarse roots; few fine and few medium tubular pores; few pressure faces; common distinct and few prominent clay films on faces of peds; neutral (pH 7.3); abrupt smooth boundary. (4 to 12 inches thick)
Btq--23 to 25 inches; light brown (7.5YR 6/4) gravelly clay, brown (7.5YR 4/4) moist; moderate medium angular blocky structure; hard, firm, moderately sticky and very plastic; few very fine and few fine roots; few very fine tubular pores; 20 percent pebble-size detached duripan fragments; common distinct clay films on faces of peds; slightly alkaline (pH 7.4); abrupt smooth boundary. (0 to 5 inches thick)
Bqm--25 to 28 inches; pink (7.5YR 7/3) duripan, brown (7.5YR 5/4) moist; strong thick platy structure; very rigid; indurated by secondary silica; widely spaced fractures in the upper inch; thin laminar caps of opal on top of peds; slightly alkaline (pH 7.4); abrupt wavy boundary. (2 to 20 inches thick)
R--28 inches; hard vesicular basalt.
TYPE LOCATION: Klamath County, Oregon; about 1.5 miles south of Barnes Valley Creek, 0.75 miles north of Wildhorse Creek, and 100 feet east of the CCC road; 550 feet north and 800 feet east of the southwest corner of section 27, T. 39 S., R. 14 E.; USGS Gerber Reservoir 7.5 minute topographic quadrangle; 42 degrees 9 minutes 10 seconds north latitude and 121 degrees 3 minutes 11 seconds west longitude, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in winter and spring, dry in summer and fall; xeric moisture regime that borders on aridic.
Mean annual soil temperature - 45 to 47 degrees F.
Mean summer soil temperature - 59 to 61 degrees F.
Mollic epipedon thickness - 7 to 15 inches; includes the Bt1 horizon in some pedons.
Argillic horizon thickness - 7 to 16 inches.
Depth to base of argillic horizon - 20 to 30 inches.
Depth to duripan - 20 to 30 inches.
Duripan thickness - 2 to 20 inches.
Depth to bedrock - 25 to 40 inches to a lithic contact.
Particle-size control section - Clay content: 35 to 45 percent; Rock fragments: 5 to 25 percent, mainly pebbles and cobbles. Lithology of fragments is dominantly basalt.
Reaction - Neutral or slightly alkaline.
Other features - Some pedons have Bt3 horizons.
A1 horizon - Hue: 10YR or 7.5YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Very cobbly loam or very stony loam.
Clay content: 22 to 27 percent.
Rock fragments: 35 to 55 percent.
Organic matter content: 2 to 4 percent.
A2 horizon (when present) - Hue: 10YR or 7.5YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Cobbly loam, cobbly clay loam, very cobbly loam, and very cobbly clay loam.
Clay content: 26 to 34 percent.
Rock fragments: 15 to 45 percent.
Organic matter content: 2 to 4 percent.
Bt1 horizon - Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 2 through 4, dry or moist.
Texture: Clay loam, cobbly clay loam, and very cobbly clay loam.
Clay content: 32 to 40 percent.
Rock fragments: 5 to 40 percent.
Organic matter content: 1 to 3 percent.
Bt2 horizon - Hue: 10YR or 7.5YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Clay or cobbly clay.
Clay content: 40 to 55 percent.
Rock fragments: 0 to 20 percent.
Organic matter content: 1 to 3 percent.
Btq horizon (when present) - Value: 5 through 7 dry, 3 or 4 moist.
Chroma: 3 through 6, dry or moist.
Texture: Clay or gravelly clay.
Clay content: 45 to 60 percent.
Rock fragments: 5 to 20 percent, mainly as basalt cobbles or as pebble-size detached fragments of duripan which have cementation classes ranging from strongly cemented through indurated.
Bqm horizon - Value: 7 or 8 dry, 4 through 6 moist.
Chroma: 3 through 6, dry or moist.
Cementation: Indurated or very strongly cemented.
COMPETING SERIES: These are the Budlewis, Forvic, Hatpeak, Manard, Oshone, Peevywell, and Repmis series. Budlewis soils have calcic horizons above the duripan. Forvic soils have mollic epipedons that are 20 to 30 inches thick and have paralithic contacts between 24 and 50 inches. Hatpeak and Peevywell soils have bedrock deeper than 40 inches. Oshone soils do not have lithic contacts within 60 inches. Manard soils have texture of silty clay loam or silty clay in the argillic horizon, have secondary carbonates in the duripan, and are drier in the moisture control section. Repmis soils have calcic horizons above the duripan and do not have lithic contacts within 60 inches.
GEOGRAPHIC SETTING: Dranket soils are on plateaus. They typically occur on summit positions. These soils formed in volcanic ash derived from dacite and residuum derived from basalt. Slopes are 0 to 15 percent. Elevations range from 4,800 to 5,400 feet. The climate is characterized by cold, wet winters and warm, dry summers. The mean annual precipitation is 16 to 20 inches. The mean annual temperature is 43 to 45 degrees F., mean January temperature is 25 to 28 degrees F., and the mean July temperature is 56 to 60 degrees F. The frost-free period is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Casebeer, Drakce, and Norcross soils. Casebeer soils are clayey, shallow to thin duripans over hard bedrock, and have ochric epipedons. Drakce soils are clayey-skeletal, deep to lithic contacts, and have a mesic temperature regime. Norcross soils are clayey and are shallow to duripans over hard bedrock.
DRAINAGE AND PERMEABILITY: Well drained; high surface runoff; slow permeability.
USE AND VEGETATION: Dranket soils are used for livestock grazing, wildlife habitat, and recreation. The native vegetation is Idaho fescue, bluebunch wheatgrass, low sagebrush, and western juniper.
DISTRIBUTION AND EXTENT: Southcentral Oregon. These soils are moderately extensive. MLRA 21.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES PROPOSED: Klamath County (Gerber Block of Fremont National Forest Area), Oregon 1998. The name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 8 inches (A1 and A2 horizons).
Argillic horizon - The zone from 8 to 25 inches (Bt1, Bt2, and Btq horizons).
Duripan - The zone from 25 to 28 inches (Bqm horizon).
Lithic contact - The boundary at 28 inches to underlying hard bedrock (R layer).
Particle-size control section - The zone from 8 to 25 inches (Bt1, Bt2, and Btq horizons).