LOCATION CHILLYBU IDEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, euic Terric Cryosaprists
TYPICAL PEDON: Chillybu muck--on a 1 percent, slightly concave, north facing slope at 6,300 feet elevation with sedge and rush vegetation. (Colors are for moist soil unless otherwise noted. When described on September 23, 1987, the soil was moist throughout.)
Oa1--0 to 7 inches; black (10YR 2/1) on broken face and rubbed, muck; about 70 percent fibers, about 10 percent after rubbing; weak medium granular structure; many very fine and fine, common medium, and few coarse roots; strongly effervescent; slightly alkaline (pH 7.4); clear smooth boundary.
Oa2--7 to 13 inches; dark brown (10YR 3/3) and very dark brown (10YR 2/2) on broken face and very dark gray (10YR 3/1) rubbed, muck; about 60 percent fibers, about 10 percent after rubbing; massive; many very fine and fine, common medium, and few coarse roots; strongly effervescent; slightly alkaline (pH 7.7); clear smooth boundary.
Oa3--13 to 18 inches; very dark brown (10YR 2/2) on broken face and very dark gray (10YR 3/1) rubbed, muck; about 50 percent fibers, about 5 percent after rubbing; massive; many very fine and common fine and medium roots; strongly effervescent; slightly alkaline (pH 7.8); clear smooth boundary.
Oa4--18 to 31 inches; dark brown (10YR 3/3) and very dark brown (10YR 2/2) on broken face and very dark grayish brown (10YR 3/2) rubbed, muck; about 60 percent fibers, about 10 percent after rubbing; massive; many very fine and fine and few medium roots; slightly effervescent; slightly alkaline (pH 7.8); clear smooth boundary.
Oa5--31 to 42 inches; very dark brown (10YR 2/2) on broken face and black (10YR 2/1) rubbed, muck; about 70 percent fibers, about 10 percent after rubbing; massive; many very fine and fine common medium roots; slightly effervescent; neutral (pH 6.8); clear smooth boundary. (Combined thickness of the O horizons is 25 to 50 inches)
2Cg--42 to 60 inches; dark greenish gray (5BG 4/1) very gravelly loam, greenish gray (5BG 5/1) dry; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine and fine tubular pores; 40 percent gravel; slightly alkaline (pH 7.5).
TYPE LOCATION: Custer County, Idaho; about 1 mile northwest of Whiskey Springs; about 1,600 feet west and about 1,800 feet north from the southeast corner of section 21, T.9N, R.22E. Latitude - 44 degrees, 05 minutes, 36 seconds North; Longitude - 113 degrees, 51 minutes, 11 seconds West.
RANGE IN CHARACTERISTICS:
Average annual soil temperature - 32 to 36 degrees F.
Average summer soil temperature - 42 to 48 degrees F.
Depth to high water table - +6 inches to 6 inches below the surface
Organic layers - 25 to 50 inches thick, predominantly sapric material but some pedons have small amounts of hemic material
Surface tier
value - 1 through 3 moist or dry
chroma - 1 through 3 moist or dry
Subsurface tier
value - 2 or 3 moist or dry
chroma - 1 through 3 moist or dry
reaction - neutral or slightly
Bottom tier
Organic soil
value - 2 or 3 moist or dry
chroma - 1 or 2 moist or dry
reaction - neutral to moderately alkaline
Mineral soil
hue - 5GB, 5Y, 5G
value - 4 or 5 moist, 5 or 6 dry
chroma - 1 or 2 moist or dry
texture - GRV-L, GRV-SL
coarse fragments - 40 to 60 percent
reaction - slightly or moderately alkaline
COMPETING SERIES: This is the Maybeso series. Maybeso soils can contain up to 15 percent woody fragments and native vegetation is dominated by trees.
GEOGRAPHIC SETTING: Chillybu soils are on flood plains. These soils formed in material derived from herbaceous plants over mineral soil. Slopes are 0 to 2 percent. Elevations are 4,800 to 7,500 feet. The climate is cold and moist in winter and spring and cool in summer. Average annual precipitation is 10 to 16 inches. Average annual temperature is 36 to 42 degrees F. The frost-free period is 15 to 55 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bigrant, Dickeypeak, and Thosand soils. Bigrant and Dickeypeak soils are on stream terraces and fan terraces and are formed of mineral soil throughout. Bigrant soils have fine-silty particle-size control sections. Dickeypeak soils have fine-loamy particle-size control sections. Thosand soils are on valley flats and have fine-loamy particle-size control sections.
DRAINAGE AND PERMEABILITY: Very poorly drained. Runoff is very slow or ponded. Permeability is moderate. These soils are frequently flooded from May through July for brief periods of 3 to 5 days.
USE AND VEGETATION: Pasture. The natural vegetation is sedges, rushes, grasses and other water loving plants.
DISTRIBUTION AND EXTENT: East-central Idaho. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Custer County, Idaho, 1999.
REMARKS: This pedon was sampled by the NSSL, Lincoln, NE. Sample #S87ID-037-002.
Diagnostic horizons and features recognized in this pedon are:
Surface tier - The zone from the surface to 12 inches (Oa1 and part of Oa2 horizons).
Subsurface tier - The zone from 12 to 36 inches (part of the Oa2, the Oa3, Oa4 and part of the Oa5 horizons).
Bottom tier - The zone from 36 to 52 inches (part of the Oa5 and part of the 2Cg horizons).