LOCATION THATCHERFLATS IDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Typic Natrixeralfs
TYPICAL PEDON: Thatcherflats silt loam, nonirrigated pasture; on a 0.5 percent slope at 4,930 feet elevation. When described on August 11, 1988, the soil was moist below 56 inches. (Color is for air dry soil unless otherwise noted.)
A1--0 to 2 inches; pale brown (10YR 6/3) silt loam, dark brown (10YR 3/3) moist; strong very fine platy structure; soft, very friable, slightly sticky and slightly plastic; common very fine roots; common very fine and fine irregular pores; moderately alkaline (pH 8.0); abrupt smooth boundary. (2 to 3 inches thick)
A2--2 to 5 inches; light yellowish brown (10YR 6/4) silt loam, brown (10YR 4/3) moist; strong coarse platy structure parting to moderate medium platy; hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; slightly effervescent; strongly alkaline (pH 8.5); abrupt wavy boundary. (0 to 4 inches thick)
Btn--5 to 9 inches; brown (10YR 5/3) silty clay, dark grayish brown (10YR 4/2) moist; strong medium columnar structure parting to strong fine and medium angular blocky; hard, friable, moderately sticky and moderately plastic; common very fine roots; few very fine tubular pores; many distinct clay films on faces of peds and in pores; slightly effervescent; strongly alkaline (pH 8.6); abrupt smooth boundary. (3 to 14 inches thick)
Btkn1--9 to 11 inches; very pale brown (10YR 8/2) silt loam, yellowish brown (10YR 5/4) moist; moderate fine angular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine roots; common very fine and fine tubular pores; common distinct clay films on faces of peds and in pores; strongly effervescent; very strongly alkaline (pH 9.4); clear wavy boundary. (2 to 8 inches thick)
Btkn2--11 to 25 inches; very pale brown (10YR 7/3) silt loam, yellowish brown (10YR 5/4) moist; moderate fine and medium angular blocky structure; hard, friable, moderately sticky and moderately plastic; few very fine roots; common very fine tubular pores; many distinct clay films on faces of peds and in pores; few fine, strongly effervescent, irregularly shaped lime filaments; strongly effervescent; very strongly alkaline (pH 9.4); gradual smooth boundary. (0 to 14 inches thick)
Bkn1--25 to 45 inches; very pale brown (10YR 7/3) silt loam, light yellowish brown (10YR 6/4) moist; massive; hard, friable, moderately sticky and moderately plastic; few very fine roots; common very fine tubular pores; few fine, strongly effervescent, irregularly shaped lime filaments; strongly effervescent; strongly alkaline (pH 9.0); gradual smooth boundary. (8 to 22 inches thick)
Bkn2--45 to 56 inches; very pale brown (10YR 7/3) silt loam, light yellowish brown (10YR 6/4) moist; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular pores; strongly effervescent; strongly alkaline (pH 9.0); gradual smooth boundary. (11 to 17 inches thick)
Bkn3--56 to 60 inches; very pale brown (10YR 7/3) silt loam, light yellowish brown (10YR 6/4) moist; few fine distinct yellowish brown (10YR 5/6) moist redox concentrations; massive; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; common very fine tubular pores; strongly effervescent; strongly alkaline (pH 8.9).
TYPE LOCATION: Caribou County, Idaho; about 1 mile north northwest of the Thatcher LDS church; about 280 feet east and 400 feet south of the northwest corner of sec. 15, T. 11 S., R. 40 E.
RANGE IN CHARACTERISTICS:
Depth to natric horizon - 2 to 7 inches
Thickness of natric horizon - 7 to 36 inches
Average annual soil temperature - 44 to 46 degrees F
Depth to redox features - 40 to 60 inches
Depth to high water table - 40 to 60 inches from March through July
Particle-size control section:
Clay content - averages 27 to 35 percent
A horizons
Value - 6 or 7 dry, 3 through 5 moist
Chroma - 3 or 4 dry or moist
Btn horizons
Value - 4 or 5 dry, 4 through 6 moist
Chroma - 2 through 4 dry or moist
Texture - SICL or SIC
Clay content - 28 to 43 percent
Btkn horizons
Hue - 10YR or 7.5YR
Value - 6 through 8 dry, 4 through 6 moist
Chroma -2 through 4 dry or moist
Texture - SIL or SICL
Bkn Horizons
Hue - 10YR or 7.5YR
Value - 6 or 7 dry, 4 through 6 moist
Chroma - 3 or 4 dry or moist
COMPETING SERIES: This is the Whitearth series. Whitearth soils are well drained.
GEOGRAPHIC SETTING: Thatcherflats soils are on slightly elevated stream terraces. Slopes range from 0 to 2 percent. Elevations range from 4,900 to 6,200 feet. The soil formed in reworked silty alluvium from loessal deposits. The average annual precipitation ranges from 13 to 16 inches, the average annual air temperature is 39 to 44 degrees F and the frost free season is 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bear Lake, Chesbrook (T), Lago (T) and Wursten series. Bear Lake, Lago and Wursten soils have mollic epipedons. Chesbrook soils lack an argillic horizon. Wursten soils have a coarse-loamy particle-size control section. Bear Lake and Chesbrook soils are commonly found in poorly drained depressional to flat positions. Lago soils are on slightly convex to smooth areas and are in complex with Bear Lake soils. Wursten soils occur on low to high terraces on well drained positions.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow runoff; slow permeability; rare flooding for brief periods March through July.
USE AND VEGETATION: Thatcherflats soils are used for nonirrigated and irrigated pasture. The potential natural vegetation is greasewood and other vegetation adapted to saline soils.
DISTRIBUTION AND EXTENT: Southeastern Idaho. The soils of this series are not extensive. MLRA 13.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Franklin County, Idaho, 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to 5 inches (A1 and A2 horizons)
Natric horizon - the zone from 5 to 25 inches (Btn, Btkn1 and Btkn2 horizons)
Particle-size control section - the zone from 5 to 25 inches (Btn, Btkn1 and Btkn2 horizons)
NSSL # S89ID029012 (partial characterization)