LOCATION STINKCREEK IDEstablished Series
TAXONOMIC CLASS: Fine-silty over sandy or sandy-skeletal, mixed, superactive, mesic Aeric Calciaquolls
TYPICAL PEDON: Stinkcreek silty clay loam--on a 0.5 percent slope at 4,485 feet elevation--rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 11 inches; very dark gray (10YR 3/1) silty clay loam, black (10YR 2/1) moist; moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; many very fine, fine and medium roots; few fine tubular pores; slightly effervescent; disseminated carbonate; very strongly alkaline (pH 9.4); clear smooth boundary. (10 to 16 inches thick)
Bk--11 to 21 inches; light gray (10YR 7/2) silty clay loam, grayish brown (10YR 5/2) moist; moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common fine roots; few fine tubular pores; few medium and fine faint brown (10YR 5/3) masses of iron accumulation; violently effervescent; disseminated carbonate; very strongly alkaline (pH 9.2); abrupt wavy boundary. (10 to 12 inches thick)
2C1--21 to 40 inches; light gray (10YR 7/2) very gravelly loamy sand, grayish brown (10YR 5/2) moist; single grain; loose, nonsticky and nonplastic; few very fine roots; few fine faint brown (10YR 5/3) masses of iron accumulation; strongly effervescent; disseminated carbonate; 50 percent gravel; moderately alkaline (pH 8.2); gradual wavy boundary. (15 to 25 inches thick)
2C2--40 to 60 inches; light gray (10YR 7/2) extremely gravelly sand, grayish brown (10YR 5/2) moist; single grain; loose, nonsticky and nonplastic; few very fine roots; strongly effervescent; disseminated carbonate; 75 percent gravel; moderately alkaline (pH 8.2).
TYPE LOCATION: Franklin County, Idaho; about 0.3 mile northwest of Franklin; approximately 1,950 feet west and 2,600 feet north of the southeast corner of section 20, T. 16 S, R. 40 E.; USGS Franklin 7.5 minute topographic quadrangle; 42 degrees 01 minute 14 seconds north latitude and 111 degrees 48 minutes 21 seconds west longitude, NAD83.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 47 to 49 degrees F.
Mollic epipedon thickness - 10 to 18 inches.
Depth to calcic horizon - 10 to 16 inches.
Depth to redoximorphic features - 10 to 16 inches.
Depth to strongly contrasting sand and gravel - 20 to 30 inches.
Particle-size control section - Clay content: Averages 18 to 35 percent in the upper part and 1 to 5 percent in the strongly contrasting lower part.
Other features - Some pedons have thin O horizons.
A horizon
Value: 3 through 5 dry, 2 or 3 moist.
Chroma: 1 or 2, dry or moist.
Rock fragments: 0 to 6 percent gravel.
Organic matter content: 3 to 5 percent.
Calcium carbonate equivalent: 5 to 15 percent.
Bk horizon
Hue: 10YR through 5Y.
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 2 or 3, dry or moist; chroma is 2 or more when hue is 2.5Y or yellower with faint redoximorphic features; chroma is 3 when hue is 2.5Y or yellower with distinct or prominent redoximorphic features.
Texture: Silt loam or silty clay loam.
Rock fragments: 0 to 6 percent gravel.
Calcium carbonate equivalent: 15 to 25 percent.
2C horizons
Hue: 10YR or 2.5Y.
Value: 6 or 7 dry, 3 through 5 moist.
Chroma: 2 or 3, dry or moist.
Texture: Very gravelly loamy sand or extremely gravelly sand.
Rock fragments: 50 to 85 percent.
Calcium carbonate equivalent: 1 to 20 percent.
Reaction: Moderately alkaline through very strongly alkaline.
COMPETING SERIES: There are currently no other series in this family.
GEOGRAPHIC SETTING: Stinkcreek soils are on stream terraces and flood plains. They formed in mixed alluvium. Slopes are 0 to 2 percent. Elevations range from 4,400 to 5,100 feet. The mean annual precipitation is 14 to 16 inches, the mean annual air temperature is 45 to 49 degrees F., and the frost-free period is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cachecan, Lewnot, and Windernot soils. Cachecan soils are on stream terraces near Stinkcreek soils. Cachecan soils are somewhat poorly drained and have a coarse-loamy particle-size class. Lewnot soils are on terraces slightly above Stinkcreek soils. Lewnot soils have a coarse-loamy particle-size control section and a seasonal high water table deeper than 24 inches. Windernot soils are on high terraces above Stinkcreek soils. Windernot soils are moderately well drained and have a sandy-skeletal particle-size class.
DRAINAGE AND PERMEABILITY: Poorly drained; very high surface runoff; moderately slow permeability (moderately high saturated hydraulic conductivity) in the upper part and very rapid permeability (very high saturated hydraulic conductivity) in the lower part. Endosaturation is present with an apparent seasonal high water table between the soil surface and 1.5 feet (very shallow and shallow free water occurrence classes) between February and June. Cumulative annual duration class is Common. These soils are susceptible to rare flooding between February and May.
USE AND VEGETATION: Stinkcreek soils are used mainly for hay, pasture, and rangeland. The potential natural vegetation is mainly sedges and tufted hairgrass.
DISTRIBUTION AND EXTENT: Southeastern Idaho. These soils are not extensive with about 1,100 acres of the series mapped to date. MLRA 28A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona.
SERIES ESTABLISHED: Franklin County, Idaho, 1997. The name is coined from a local creek.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the soil surface to 11 inches (A horizon).
Calcic horizon - The zone from 11 to 21 inches (Bk horizon).
Aquic conditions - The conditions of endosaturation, reduction, and redoximorphic features between the soil surface and 18 inches at certain times during normal years (parts of the A and Bk horizons).
Major lithologic discontinuity - The abrupt change to sandy-skeletal material at 21 inches (between the Bk and 2C1 horizons).
Particle-size control section - The zone from 10 to 40 inches (Bk and 2C1 horizons and part of the A horizon).
The superactive cation exchange activity class is estimated based on entries for data elements in NASIS.