LOCATION DEADHORSE ID
Established Series
IRD. KA/RGK/CBR/EED
05/2018
DEADHORSE SERIES
Landscape--hills, alluvial plains
Landform--fan remnants
Slope--1 to 50 percent
Parent material--loess-influenced alluvium
Mean annual precipitation--about 350 mm
Mean annual air temperature--about 5 degrees C
Depth class--moderately deep
Drainage class--well drained
Soil moisture regime--xeric
Soil temperature regime--frigid
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Typic Durixerolls
TYPICAL PEDON: Deadhorse silt loam in an area of rangeland (Colors are for dry soil unless otherwise noted.)
A1--0 to 10 cm; dark grayish brown (10YR 4/2) silt loam, dark brown (10YR 3/3) moist; weak fine subangular blocky structure parting to moderate medium granular; soft, very friable, slightly sticky and slightly plastic; common fine and very fine and few medium roots; common very fine tubular pores; 10 percent gravel; slightly alkaline (pH 7.8); clear wavy boundary
Bt--10 to 20 cm; grayish brown (10YR 5/2) gravelly silt loam, dark brown (10YR 3/3) moist; weak medium and fine subangular blocky structure; slightly hard, firm, slightly sticky and plastic; common fine and very fine and few medium roots; common very fine tubular pores; 30 percent thin clay films on ped faces and in pores; 25 percent gravel; moderately alkaline (pH 8.0); abrupt wavy boundary
Btk--20 to 33 cm; brown (10YR 5/3) very gravelly silt loam, brown (10YR 4/3) moist; moderate medium subangular blocky structure; slightly hard, firm, slightly sticky and plastic; common fine and very fine and few medium roots; common fine and very fine tubular pores; 15 percent thin clay films on ped faces; 45 percent gravel; strongly effervescent (17 percent calcium carbonate equivalent); moderately alkaline (pH 8.0); abrupt wavy boundary
Bk--33 to 53 cm; very pale brown (10YR 8/2) extremely gravelly loam, yellowish brown (10YR 5/4) moist; massive; slightly hard, firm, slightly sticky and slightly plastic; few fine and very fine roots; few very fine tubular pores; finely disseminated calcium carbonates; 60 percent gravel and 10 percent cobbles; violently effervescent (50 percent calcium carbonate equivalent); moderately alkaline (pH 8.2); abrupt wavy boundary
2Bkqm--53 to 97 cm; very pale brown (10YR 8/2) indurated duripan, light yellowish brown (10YR 6/4) moist; massive; extremely hard, extremely firm; violently effervescent; 40 percent gravel; strongly alkaline (pH 8.6); abrupt wavy boundary
3Bk--97 to 152 cm; very pale brown (10YR 8/4) very gravelly loamy sand, very pale brown (10YR 7/4) moist; massive; soft, very friable; finely disseminated carbonates; violently effervescent; 40 percent gravel and 5 percent cobbles; strongly alkaline (pH 8.8)
TYPE LOCATION: Clark County, Idaho; latitude 44.29750 degrees north, longitude 112.42667 west, datum WGS 84
RANGE IN CHARACTERISTICS:
Mean annual soil temperature--3.3 to 7.2 degrees C
Thickness of mollic epipedon--20 to 38 cm
Depth to argillic horizon--10 to 13 cm
Depth to carbonates--33 to 48 cm
Depth to duripan--53 to 86 cm
Thickness of duripan--10 to 43 cm
Particle-size control section (weighted averages)
Clay content--18 to 27 percent
Total rock fragment content--35 to 55 percent
A horizon
Value--3 to 5 dry, 2 or 3 moist
Chroma--2 or 3 dry or moist
Clay content--9 to 12 percent
Gravel content--0 to 15 percent
Reaction--pH 7.4 to7.8
Thickness--10 to 13 cm
Bt horizon
Value-- 3 to 5 dry, 3 or 4 moist
Chroma--2 or 3 dry or moist
Texture (less than 2-mm fraction)--loam, silt loam
Clay content--18 to 24 percent
Gravel content--15 to 35 percent
Reaction--pH 7.4 to 7.8
Thickness--10 to 18 cm
Btk horizon (where present)
Value--4 or 5 dry, 3 or 4 moist
Texture (less than 2-mm fraction)--loam, silt loam
Clay content--18 to 24 percent
Gravel content--35 to 65 percent
Reaction--pH 7.9 to 8.4
Thickness--13 to 18 cm
Bk horizon
Hue--7.5YR or 10YR dry or moist
Value--6 to 8 dry, 5 to 8 moist
Chroma--2 to 6 dry or moist
Texture (less than 2-mm fraction)--silt loam, loam
Clay content--18 to 24 percent
Total rock fragment content--40 to 75 percent
Gravel content--35 to 60 percent
Cobble content--5 to 15 percent
Reaction--pH 7.9 to 8.4
Thickness--20 to 38 cm
2Bkqm horizon
Value--6 to 8 moist
Chroma--2 to 4 dry or moist
Gravel content--40 to 90 percent
3C horizon
Value--7 or 8 dry
Chroma--2 to 4 dry or moist
Texture (less than 2-mm fraction)--loamy sand, sand
Clay content--4 to 13 percent
Total rock fragment content--40 to 80 percent
Gravel content--35 to 65 percent
Cobble content--5 to 15 percent
Reaction--pH 8.0 to 8.6
COMPETING SERIES: None
GEOGRAPHIC SETTING:
Elevation--1630 to 2100 m
Mean annual precipitation--300 to 425 mm
Mean annual air temperature--2.2 to 6.1 degrees C
Frost-free period--50 to 95 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class--well drained
Saturated hydraulic conductivity (Ksat)--5 to 25 um/sec above the duripan, 0.01 to 0.10 in the duripan
USE AND VEGETATION:
Major uses--rangeland, wildlife habitat
Potential natural vegetation--low sagebrush, Idaho fescue, bluebunch wheatgrass
DISTRIBUTION AND EXTENT: Small extent in southeastern Idaho; MLRA 12
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Clark County, Idaho; 2018; name from nearby stream
REMARKS:
Diagnostic horizons and other features in this pedon
Mollic epipedon--zone from the surface to a depth of 20 cm
Argillic horizon--zone from 10 to 33 cm
Duripan--zone from 53 to 97 cm
Particle-size control section--zone from 10 to 33 cm
Taxonomic version--Twelfth Edition, 2014
National Cooperative Soil Survey
U.S.A.