LOCATION WONSER ORTentative Series
TAXONOMIC CLASS: Clayey, smectitic, mesic, shallow Typic Durixerolls
TYPICAL PEDON: Wonser extremely cobbly loam--on a 2 percent slope at an elevation of 4,350 feet--rangeland. (Colors are for dry soil unless otherwise noted. The soil was dry throughout when it was described on September 16, 1998.) The soil surface is partially covered with about 25 percent pebbles, 25 percent cobbles, and 10 percent stones.
A--0 to 2 inches; grayish brown (10YR 5/2) extremely cobbly loam, very dark grayish brown (10YR 3/2) moist; strong thick and moderate thin platy structure; hard, firm, slightly sticky and slightly plastic; common very fine and few fine roots; common fine and common medium vesicular pores; 25 percent pebbles, 25 percent cobbles, and 10 percent stones; slightly alkaline (pH 7.6); abrupt smooth boundary. (2 or 3 inches thick)
Bt1--2 to 4 inches; brown (10YR 5/3) cobbly clay loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine, common fine, and few medium roots; common fine and common medium tubular pores; common faint clay films on faces of peds; 10 percent pebbles and 10 percent cobbles; slightly alkaline (pH 7.5); abrupt smooth boundary. (2 to 10 inches thick)
Bt2--4 to 6 inches; brown (10YR 5/3) cobbly clay, dark brown (10YR 3/3) moist; weak medium prismatic structure parting to strong medium subangular blocky; hard, firm, moderately sticky and moderately plastic; few very fine, few fine, and few medium roots; common fine and common medium tubular pores; few pressure faces; common faint and few distinct clay films on faces of peds; 10 percent pebbles and 8 percent cobbles; slightly alkaline (pH 7.5); abrupt smooth boundary. (2 to 8 inches thick)
Bt3--6 to 13 inches; light brown (7.5YR 6/3) cobbly clay, brown (7.5YR 4/3) moist; moderate medium prismatic structure parting to moderate medium angular blocky; very hard, very firm, moderately sticky and very plastic; few very fine, few fine, and few medium roots; few very fine tubular pores; common pressure faces; common distinct clay films on faces of peds; 10 percent pebbles and 10 percent cobbles; slightly alkaline (pH 7.5); abrupt smooth boundary. (5 to 8 inches thick)
Bqm--13 to 15 inches; reddish yellow (7.5YR 7/6) duripan, strong brown (7.5YR 5/6) moist; strong medium platy structure; very rigid; indurated by secondary silica; slightly alkaline (pH 7.6); abrupt wavy boundary. (1 to 6 inches thick)
R--15 inches; hard basalt.
TYPE LOCATION: Klamath County, Oregon; about 0.5 mile south of Threemile Reservoir and 100 feet south of Willow Valley Road; 2,500 feet south and 2,100 feet west of the northeast corner of section 10, T. 41 S., R. 14 E.; USGS Langell Valley 7.5 minute topographic quadrangle; 42 degrees 1 minutes 41 seconds north latitude and 121 degrees 9 minutes 34 seconds west longitude, NAD 27.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in winter and spring and dry in summer and fall; xeric moisture regime that borders on aridic.
Mean annual soil temperature - 47 to 49 degrees F.
Mean summer soil temperature - 60 to 62 degrees F.
Mollic epipedon thickness - 7 to 10 inches; includes the Bt1 and Bt2 horizons and part of the Bt3 horizon when the upper 7 inches of the soil is mixed.
Argillic horizon thickness - 8 to 18 inches.
Depth to base of argillic horizon - 12 to 20 inches.
Depth to duripan - 12 to 20 inches.
Duripan thickness - 1 to 6 inches.
Depth to bedrock - 13 to 26 inches to a lithic contact.
Particle-size control section - Clay content: averages 40 to 50 percent; Rock fragments: 15 to 35 percent, mainly cobbles. Lithology of fragments is basalt.
A horizon - Value: 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Clay content: 22 to 27 percent.
Rock fragments: 60 to 70 percent.
Reaction: Neutral or slightly alkaline.
Organic matter content: 2 to 4 percent.
Bt1 horizon - Hue: 10YR or 7.5YR.
Value: 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Cobbly clay loam or very cobbly clay loam.
Clay content: 30 to 40 percent.
Rock fragments: 15 to 45 percent.
Reaction: Neutral or slightly alkaline.
Organic matter content: 2 to 4 percent.
Bt2 horizon - Hue: 10YR or 7.5YR.
Chroma: 3 or 4 dry.
Texture: Clay or cobbly clay.
Clay content: 40 to 55 percent.
Rock fragments: 5 to 35 percent.
Reaction: Slightly alkaline or moderately alkaline.
Organic matter content: 1 to 3 percent.
Other features: Some pedons have texture of very cobbly clay.
Bt3 horizon - Hue: 7.5YR or 10YR.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Cobbly clay or very cobbly clay.
Clay content: 50 to 60 percent.
Rock fragments: 15 to 40 percent.
Reaction: Slightly alkaline or moderately alkaline.
Organic matter content: 1 to 3 percent.
Bqm horizon - Hue: 7.5YR or 10YR.
Value: 7 or 8 dry, 5 or 6 moist.
Chroma: 4 or 6, dry or moist.
Reaction: Slightly alkaline or moderately alkaline.
Cementation: Indurated or very strongly cemented.
Other features: Some pedons have minor amounts of identifiable secondary carbonates.
COMPETING SERIES: This is the Niva (T) series. Niva soils are greater than 60 inches to bedrock and have frost-free periods of 120 to 150 days.
GEOGRAPHIC SETTING: Wonser soils are on plateaus. They typically occur on summit positions. These soils formed in volcanic ash derived from dacite and in residuum derived from basalt. Slopes are 0 to 4 percent. Elevations range from 4,200 to 5,000 feet. The climate is characterized by cold, wet winters and warm, dry summers. The mean annual precipitation is 14 to 16 inches. The mean annual temperature is 45 to 47 degrees F., mean January temperature is 27 to 30 degrees F., and the mean July temperature is 58 to 62 degrees F. The frost-free period is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Notchcorral and Woolencanyon soils. Notchcorral soils are fine, moderately deep to duripans over bedrock, have mollic epipedons, and have argillic horizons with abrupt clay increases. Woolencanyon soils are clayey, shallow to duripans over bedrock, have mollic epipedons, and have argillic horizons with abrupt clay increases.
DRAINAGE AND PERMEABILITY: Well drained; high surface runoff; slow permeability.
USE AND VEGETATION: Wonser soils are used for livestock grazing, wildlife habitat, and recreation. The native vegetation is bluebunch wheatgrass, Idaho fescue, low sagebrush, and western juniper.
DISTRIBUTION AND EXTENT: Southcentral Oregon. These soils are not 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 7 inches (A, Bt1, and Bt2 horizons and part of the Bt3 horizon).
Argillic horizon - The zone from 2 to 13 inches (Bt1, Bt2, and Bt3 horizons).
Duripan - The zone from 13 to 15 inches (Bqm horizon).
Lithic contact - The boundary at 15 inches to underlying hard bedrock (R layer).
Particle-size control section - The zone from the soil surface to 13 inches (A, Bt1, Bt2, and Bt3 horizons).