LOCATION THATCHER UT+IDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Calcic Argixerolls
TYPICAL PEDON: Thatcher silt loam, on a northeast facing convex-concave slope of 4 percent in abandoned cropland. When described the soil was dry throughout. (Colors are for moist soil unless otherwise noted.)
A1--0 to 7 inches; dark brown (10YR 3/3) silt loam, dark yellowish brown (10YR 4/4) dry; weak fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine and fine roots and few medium and coarse roots; neutral (pH 7.0); clear smooth boundary. (3 to 13 inches thick)
A2--7 to 13 inches; dark brown (7.5YR 3/3) silt loam, dark yellowish brown (10YR 4/4) dry; weak fine and medium subangular blocky structure; hard, friable, slightly sticky, plastic; common very fine and fine roots; and few medium and coarse roots; many very fine and fine pores; neutral (pH 7.2); gradual, wavy boundary. (0 to 10 inches thick)
Bt1--13 to 23 inches; brown (7.5YR 4/4) silty clay loam, brown (7.5YR 5/4) dry; moderate medium and coarse subangular blocky structure; very hard, friable, slightly sticky, plastic; few fine and medium roots; many very fine pores; common faint clay films; neutral (pH 7.2); gradual, wavy boundary. (4 to 10 inches thick)
Bt2--23 to 31 inches; brown (7.5YR 4/4) silty clay loam, brown (7.5YR 5/4) dry; moderate fine and medium subangular blocky structure; very hard, firm, slightly sticky, plastic; few fine and medium roots; many very fine pores; many faint clay films; slightly alkaline (pH 7.4); clear, wavy boundary. (5 to 16 inches thick)
Btk--31 to 42 inches; reddish brown (5YR 4/4) silty clay loam, light reddish brown (5YR 6/4) dry; moderate medium subangular blocky structure; extremely hard, friable, slightly sticky, plastic; few fine roots; many very fine pores; strongly effervescent, lime is veined; strongly alkaline (pH 8.6); gradual, wavy boundary. (0 to 16 inches thick)
Bk1--42 to 51 inches; yellowish red (5YR 4/6) loam, yellowish red (5YR 5/6) dry; weak medium and coarse subangular blocky structure; extremely hard, friable, slightly sticky, plastic; few fine roots; many very fine pores; violently effervescent, lime is disseminated; strongly alkaline (pH 8.8); clear, wavy boundary. (7 to 26 inches thick)
Bk2--51 to 60 inches; yellowish red (5YR 4/6) fine sandy loam, yellowish red (5YR 5/6) dry; massive; hard, friable, nonsticky and nonplastic; few fine roots; violently effervescent, lime is disseminated; strongly alkaline (pH 8.9).
TYPE LOCATION: Rich County, Utah; 7 1/2 miles east and 8 miles north of Laketown; 2,200 feet west and 900 feet north of the SE corner of Section 20., T. 14 N., R. 7 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 42 to 47 degrees F. and the mean summer temperature is 60 to 64 degrees F. The soil is dry in all parts of the moisture control section for 60 to 75 or more consecutive days within the 4 months following the summer solstice.
Thickness of the mollic epipedon is 10 to 19 inches and depth to the argillic horizon is 8 to 19 inches. Depth to the calcic horizon ranges from 16 to 44 inches. The particle size control section contains 5 to 15 percent fine sand or coarser.
The A1 horizon has hue of 5YR, 7.5YR or 10YR, value of 3 to 5 dry, 2 to 3 moist, and chroma of 2 to 4 dry and 1 to 3 moist. Gravel content range from 0 to 20 percent. Reaction is neutral to moderately alkaline, and noneffervescent to slightly effervescent.
The Bt horizon has hue of 5YR to 10YR, value of 4 to 7 dry, 3 to 5 moist and chroma of 2 to 6 dry and moist. It is commonly silty clay loam, silt loam, and less commonly clay loam with less than 15 percent coarser than very fine sand. Clay content ranges 25 to 35 percent. It is neutral to moderately alkaline.
The Btk horizon has hue of 5YR to 10YR, value of 5 to 7 dry, 4 to 6 moist, and chroma of 2 to 6 dry, 3 to 8 moist. It is silt loam, silty clay loam, clay loam, or loam. Clay content ranges 25 to 35 percent. Total rock fragments range from 0 to 15 percent, containing 0 to 15 percent gravel and 0 to 5 percent cobble. It is slightly alkaline to strongly alkaline.
The Bk and C horizons have hue of 2.5YR, 5YR, 7.5YR or 10YR, value of 5 to 8 dry, 3 to 8 moist and chroma of 2 to 8. It is commonly stratified loam, silt loam, sandy loam, fine sandy loam, very fine sandy loam, silty clay loam, gravelly loam or very gravelly loam. Rock fragment content ranges from 0 to 50 percent, dominantly gravel. Cobble ranges from 0 to 15 percent. Reaction is slightly alkaline to very strongly alkaline. Sodium absorption ratio is less than 15 and electrical conductivity is less than 2 millimhos per centimeter.
COMPETING SERIES: These are the Bancroft (ID), Chatburn (ID), Elevator (ID) and Komondor (ID)series. Bancroft soils formed in loess and have less than 5 percent fine sand or coarser in the particle size control section. Chatburn soils have sodium absorption ratios greater than 15 and electrical conductivity greater than 8 millimhos per cm. in the Bkz horizon. Elevator soils are moderately well drained and have mottles in the calcic horizon. Komondor soils have a calcic horizon at depths of less than 16 inches.
GEOGRAPHIC SETTING: Thatcher soils are on concave to convex foothill slopes, hills, alluvial fans, and terraces at elevations of 4,700 to 7,500 feet. Slope ranges from 0 to 30 percent. The soils formed in colluvium, alluvium, and lake sediments derived mainly from sandstone and quartzite, but contains some limestone and chert. Mean annual precipitation ranges from 12 to 18 inches, and mean annual temperature ranges from 39 to 45 degrees F. The frost-free period is 60 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ant Flat, Bear Lake, Dagan, Dennor, Ellett, Falula, Kearl, and Gobine soils. Ant Flat soils have more than 35 percent clay in the control section. Bear Lake soils lack an argillic horizon and have characteristics associated with wetness. Dagan, Dennor, Falula, Kearl, Varangi, and Gobine soils do not have argillic horizons. Dagan, Dennor, and Falula soils also have more than 35 percent rock fragments in the control section. Kearl soils are underlain by bedrock between depths of 20 and 40 inches. Ellett soils are shallow over soft shale beds.
DRAINAGE AND PERMEABILITY: Well drained; runoff is medium to rapid; permeability is moderately slow.
USE AND VEGETATION: The soil is used for irrigated and nonirrigated cropland, rangeland and wildlife habitat. Native vegetation is dominantly big sagebrush, fescue, bluebunch wheatgrass and yellowbrush.
DISTRIBUTION AND EXTENT: This series is moderately extensive in northeastern Utah and southeastern Idaho. MLRA 13 and 43B.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Soda Springs-Bancroft Area, Idaho, 1925.
REMARKS: The type location was changed from Franklin County, Idaho to Rich County, Utah, 1979.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon -The zone from the surface to a depth of 13 inches.(A1 and A2 horizons).
Argillic horizon - the zone from 13 inches to 42 inches.(Bt1, Bt2, and Btk horizons).
Calcic horizon - the zone from 42 to 60 inches.(Bk1, and Bk2 horizons).