LOCATION CARRBUTTE ORTentative Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Pachic Ultic Argixerolls
TYPICAL PEDON: Carrbutte stony loam--on a 12 percent slope at an elevation of 4,920 feet--forestland. (Colors are for dry soil unless otherwise noted. The soil was dry to 10 inches and slightly moist below 10 inches, when it was described on October 7, 1998.) The soil surface is covered by a one inch layer of undecomposed to slightly decomposed pine needles.
A1--0 to 3 inches; brown (10YR 5/3) stony loam, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; soft, very friable, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine and common fine interstitial pores; 15 percent pebbles, 5 percent cobbles, and 8 percent stones; neutral (pH 6.8); abrupt smooth boundary. (2 to 4 inches thick)
A2--3 to 10 inches; brown (7.5YR 4/3) very cobbly loam, dark brown (7.5YR 3/2) moist; moderate medium subangular blocky structure parting to strong medium granular; soft, friable, slightly sticky and slightly plastic; common very fine, common fine, common medium, and few coarse roots; common very fine and common fine interstitial and tubular pores; 15 percent pebbles, 20 percent cobbles, and 5 percent stones; neutral (pH 6.8); clear smooth boundary. (6 to 14 inches thick)
Bt1--10 to 21 inches; brown (7.5YR 5/3) very cobbly clay loam, dark brown (7.5YR 3/3) moist; strong medium subangular blocky structure parting to weak fine angular blocky; slightly hard, firm, moderately sticky and moderately plastic; few very fine, common fine, few medium, and few coarse roots; few very fine and few fine tubular pores; common faint and few distinct clay films on faces of peds; 20 percent pebbles and 15 percent cobbles; neutral (pH 7.0); clear smooth boundary. (7 to 14 inches thick)
Bt2--21 to 41 inches; brown (7.5YR 5/4) very cobbly clay, dark brown (7.5YR 3/4) moist; strong medium subangular blocky structure parting to moderate medium angular blocky; hard, firm, moderately sticky and very plastic; few very fine, few fine, and few medium roots; few very fine and few fine tubular pores; common distinct clay films on faces of peds; 20 percent pebbles and 15 percent cobbles; neutral (pH 7.0); clear wavy boundary. (10 to 24 inches thick)
Crt--41 to 57 inches; light brown (7.5YR 6/4) weathered basalt, brown (7.5YR 4/4) moist; few distinct clay films on pararock fragments and few seams of illuvial clay lining fractures in the bedrock. (10 to 24 inches thick)
R--57 inches; hard, unweathered basalt.
TYPE LOCATION: Klamath County, Oregon; about 0.2 miles east of Rock Creek and 200 feet south of the State Line road; 1,000 feet north and 1,200 feet west of the southeast corner of section 17, T. 41 S., R. 15 E.; USGS Antler Point 7.5 minute topographic quadrangle; 42 degrees 0 minutes 30 seconds north latitude and 120 degrees 57 minutes 39 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 - 20 to 30 inches, includes all subdivisions of the argillic horizon in some pedons.
Argillic horizon thickness - 18 to 36 inches.
Depth to base of argillic horizon - 40 to 50 inches.
Depth to bedrock - 40 to 60 inches to a paralithic contact. The paralithic material below the contact is weathered basalt.
Particle-size control section - Clay content: 35 to 50 percent; Rock fragments: 35 to 50 percent, mainly cobbles. Lithology of fragments is basalt.
A1 horizon - Hue: 10YR or 7.5YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Clay content: 22 to 27 percent.
Rock fragments: 15 to 35 percent.
Reaction: Slightly acid or neutral.
Organic matter content: 2 to 4 percent.
A2 horizon - Hue: 10YR or 7.5YR.
Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 2 or 3, dry or moist.
Texture: Cobbly loam or very cobbly loam.
Clay content: 20 to 27 percent.
Rock fragments: 15 to 40 percent.
Reaction: Slightly acid or neutral.
Organic matter content: 2 to 4 percent.
Bt1 horizon - Value: 4 or 5 dry, 2 or 3 moist.
Chroma: 3 or 4 dry, 2 or 3 moist.
Texture: Very cobbly clay loam or very cobbly clay.
Clay content: 35 to 45 percent.
Rock fragments: 35 to 45 percent.
Organic matter content: 1 to 3 percent.
Bt2 horizon - Value: 4 or 5 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Clay content: 40 to 55 percent.
Rock fragments: 35 to 50 percent, mainly as cobbles.
Organic matter content: 0.5 to 2 percent.
COMPETING SERIES: These are the Skookum and Wellsbench (T) series. Skookum soils are moderately deep to lithic contacts. Wellsbench soils are deep to lithic contacts.
GEOGRAPHIC SETTING: Carrbutte soils are on hills. They occur in plateau landscapes. These soils formed in loess and residuum derived from basalt and tuff. Slopes are 2 to 20 percent. Elevations range from 4,700 to 5,200 feet. The climate is characterized by cold, wet winters and warm, dry summers. The mean annual precipitation is 16 to 18 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: This is the Grohs soil. Grohs soils are fine, moderately deep to paralithic contacts, and have argillic horizons and thick mollic epipedons.
DRAINAGE AND PERMEABILITY: Well drained; high surface runoff; slow permeability.
USE AND VEGETATION: Carrbutte soils are used for timber production, wildlife habitat, livestock grazing, and recreation. The native vegetation is a forest canopy of ponderosa pine with an understory of Ross sedge, Idaho fescue, and squawcarpet.
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 from a large butte in the area.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 21 inches (A1, A2, and Bt1 horizons).
Argillic horizon - The zone from 10 to 41 inches (Bt1 and Bt2 horizons).
Paralithic contact - The boundary at 41 inches to underlying soft, weathered bedrock (Crt layer).
Particle-size control section - The zone from 10 to 30 inches (Bt1 horizon and most of the Bt2 horizon).