LOCATION COSBIE ORTentative Series
TAXONOMIC CLASS: Loamy over ashy or ashy-pumiceous, mixed over glassy, superactive, nonacid Aquandic Cryaquents
TYPICAL PEDON: Cosbie supporting the lodgepole pine/widefruit sedge plant association on a 2 percent slope at 4875 feet. When described on 18 August 1999 the soil was wet throughout (colors are for dry soil unless otherwise noted).
Oe--0 to 4 inches; dark gray (10YR 4/1) moderately decomposed plant material, very dark brown (10YR 2/2) moist; weak fine granular structure; soft, very friable, non-sticky and non-plastic; many very fine and fine roots, common medium roots; 65 percent non-rubbed fiber, 40 percent rubbed fiber; slightly acid (pH 6.4); abrupt smooth boundary. (2 to 8 inches thick)
A1--4 to 12 inches; gray (10YR 5/1) mucky diatomaceous silt, black (2.5Y 2.5/1) moist, dark gray (10YR 4/1) dried and remoistened; strong fine granular structure; soft, very friable, slightly sticky and slightly plastic; many very fine roots, common fine roots, few medium roots; many fine interstitial pores; moderately acid (pH 5.8); abrupt smooth boundary. (5 to 23 inches thick)
A2--12 to 20 inches; gray (10YR 6/1) diatomaceous silt, dark gray (10YR 4/1) moist, grayish brown (10YR 5/2) dried and remoistened; weak coarse platy structure parting to moderate fine platy; hard, firm, slightly sticky and slightly plastic; common very fine roots, few fine roots; common fine tubular pores; slightly acid (pH 6.2); abrupt smooth boundary. (0 to 18 inches thick)
2BCc--20 to 51 inches; variegated very paragravelly ashy coarse sand; single grain; loose, non-sticky and non-plastic; few fine roots; many fine interstitial pores; 50 percent pumice paragravel; few coarse dark yellowish brown (10YR 4/4) moist iron masses in matrix; common medium black (2.5Y 2.5/1) manganese nodules in matrix; neutral (pH 6.6). (12 to 59 inches thick)
3Ab--51 to 75 inches; light olive brown (2.5Y 5/3) gravelly sandy loam; very dark gray (10YR 3/1) moist; very friable, non-sticky and slightly plastic; 20 percent gravel; neutral (pH 6.6).
TYPE LOCATION: Klamath County, Oregon, about 10 miles south and 14 miles east of Chemult, about 2250 feet east and 1970 feet north of the southwest corner of section 4, T. 29 S., R. 10 E. (Latitude 43 degrees, 5 minutes, 8 seconds North, Longitude 121 degrees, 32 minutes, 18 seconds West)
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 35 to 40 degrees F
Mean winter soil temperature - 32 to 35 degrees F
Mean summer soil temperature - 40 to 453 degrees F
Depth to the ashy or ashy-pumiceous material (2BC) - 14 to 23 inches
Depth to aquic conditions - at the soil surface
Oe horizon
Thickness: 2 to 8 inches (too thin to qualify as a histic epipedon)
Hue, non-rubbed: 10YR dry or moist
Value, non-rubbed: 3 or 4 dry, 2 or 3 moist
Chroma, non-rubbed: 1 or 2 dry or moist
Non-rubbed fiber content: 50 to 95 percent
Rubbed fiber content: 20 to 50 percent
Reaction: strongly acid to slightly acid (pH 5.1 to 6.5)
A1 horizon
Thickness: 5 to 23 inches
Hue, non-rubbed: 10YR or 2.5Y dry, moist, or dried and remoistened
Value, non-rubbed: 4, 5 or 6 dry; 2, 2.5 or 3 moist; 4, 5 or 6 dried and remoistened
Chroma, non-rubbed: 1 or 2 dry, moist, or dried and remoistened
Clay content: less than 8 percent
Silt content: greater than 90 percent
Organic matter content: 10 to 24 percent
Non-rubbed fiber content: 0 to 40 percent
Rubbed fiber content: 0 to 5 percent
n Value: greater than 1.0
Reaction: strongly acid to slightly acid (pH 5.1 to 6.5)
A2 horizon
Depth to: 5 to 23 inches
Thickness: 0 to 18 inches
Hue: 10YR or 2.5Y dry, moist, or dried and remoistened
Value: 5 or 6 dry; 2, 2.5, 3, 4 or 5 moist and fresh; 5 or 6 dried and remoistened
Chroma: 1 or 2 dry, moist, or dried and remoistened
Clay content: less than 8 percent
Silt content: greater than 90 percent
Pumice paragravel content: 0 to 10 percent
Organic matter content: 7 to 10 percent
n Value: greater than 0.7 percent
Reaction: moderately acid or slightly acid (pH 5.6 to 6.5)
Redoximorphic features: absent to common, fine iron masses; absent to common, fine manganese masses
2BCc horizon
Depth to: 14 to 23 inches
Thickness: 12 to 59 inches
Hue: 10YR, 2.5Y or variegated dry or moist
Value: 5, 6, 7 or 8 dry; 4 or 6 moist
Chroma: 2, 3 or 4 dry or moist
Texture: ashy coarse sand or ashy loamy coarse sand
Pumice paragravel content: 35 to 80 percent
Volcanic glass content: 60 to 100 percent in the 0.02 to 2.0 mm fraction
Ammonium oxalate extractable Al plus 1/2 Fe: 0.2 to 0.4 percent
Phosphate retention: 10 to 25 percent
Redoximorphic features: absent to common, fine or medium iron masses; absent to common iron surface coats; common or many, fine manganese nodules; few or common, fine iron-manganese nodules; absent to common, fine or medium manganese masses
Reaction: moderately acid to neutral (pH 5.6 to 7.3)
3Ab horizon
Depth to: 40 to 80 inches
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING:
Landscape - lava plateau
Landform - drainageways
Elevation - 4575 to 5630 feet
Slope - 1 to 6 percent
Parent material - grassy organic material over diatomaceous earth over alluvium from Mt. Mazama pumice over alluvium from basalt
Climate - cold, moist winters and cool, dry summers
Mean annual air temperature - 41 to 45 degrees F
Mean January air temperature - 25 to 27 degrees F
Mean July air temperature - 57 to 60 degrees F
Mean annual precipitation - 20 to 32 inches
Frost-free period - 5 to 35 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Lapine, Chinchallo and Chemult soils. Lapine soils are on adjacent plateaus and formed in volcanic ash and pumice, and are excessively drained. Chinchallo soils are on nearby flood plains and lake basins and have a layer of diatomaceous earth having an n Value of less than 0.7. Chemult soils are on nearby flood plains and have a histic epipedon.
DRAINAGE AND PERMEABILITY:
Drainage - very poorly drained
Permeability - very slow
Flooding - frequent
Ponding - frequent
Water table - an apparent high water table is at its uppermost limit from April to August
USE AND VEGETATION: Cosbie soils are used for wildlife habitat, watershed and recreation. The potential natural plant community is the lodgepole pine/widefruit sedge plant association (CLM1-13).
DISTRIBUTION AND EXTENT: Klamath County, Oregon; MLRA 6. Series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Winema National Forest, Klamath County, Oregon, 2001
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon
Limnic soil materials, diatomaceous earth in a gelatinous or semi-gelatinous state - from 4 to 20 inches (the A horizon)
n Value of greater than 0.7 - from 4 to 20 inches (the A horizon)
Lithologic discontinuity - 20 inches and 51 inches
Particle-size control section - from 10 to 40 inches. From 10 to 20 inches is coarse-silty and from 20 to 40 is ashy-pumiceous.
Aquic conditions - endosaturation on 18 August 1999 from 0 to 75 inches (the Oe, A1, A2, 2BCc and 3Ab horizons)
Moisture regime - aquic
Temperature regime - cryic
ADDITIONAL DATA: This pedon description is in NASIS pedon with Site ID 99-JFD-04.