LOCATION SCOTTY WY
Tentative Series
IRD DMM-DJP-CBR
04/2018
SCOTTY SERIES
The Scotty series consists of very deep, somewhat excessively to well drained soils that formed in slope alluvium and colluvium derived from conglomerate. These soils are on hillslopes, fan remnants and strath terraces. Slopes are 1 to 30 percent. Mean annual precipitation is about 250 mm, and mean annual air temperature is about 6.0 degrees C.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Aridic Haplustepts
TYPICAL PEDON: Scotty gravelly sandy loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 9 cm; brown (10YR 5/3) gravelly sandy loam, brown (10YR 4/3) moist; weak fine granular structure; very friable, soft, nonsticky, nonplastic; many fine roots; many fine interstitial pores; 30 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary. (7 to 12 cm thick)
Bw--9 to 22 cm; yellowish brown (10YR 5/4) gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; weak medium subangular blocky structure; very friable, soft, nonsticky, nonplastic; many fine roots; many fine interstitial pores; 25 percent gravel; slightly alkaline (pH 7.4); clear smooth boundary (12 to 21 cm thick)
Bk--22 to 37 cm; yellowish brown (10YR 5/4) very gravelly sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; very friable, soft, nonsticky, nonplastic; common fine roots; many fine interstitial pores; 20 percent calcium carbonate coats on rock fragments; finely disseminated calcium carbonates; 40 percent gravel; slightly effervescent; 3 percent calcium carbonate equivalent; slightly alkaline (pH 7.8); clear smooth boundary. (14 to 30 cm thick)
BCk--37 to 70 cm; yellowish brown (10YR 5/6) very gravelly loamy coarse sand, dark yellowish brown (10YR 4/6) moist; single grain; loose, nonsticky, nonplastic; few fine roots; many fine interstitial pores; 30 percent calcium carbonate coats on rock fragments; finely disseminated calcium carbonates; 45 percent gravel; slightly effervescent; 3 percent calcium carbonate equivalent; slightly alkaline (pH 7.8); gradual wavy boundary. (30 to 35 cm thick)
C--70 to 150 cm; yellowish brown (10YR 5/6) very gravelly loamy coarse sand, dark yellowish brown (10YR 4/6) moist; single grain; loose, nonsticky, nonplastic; very few fine roots; many fine interstitial pores; 45 percent gravel; slightly alkaline (pH 7.4).
TYPE LOCATION: Sweetwater County, Wyoming; USGS Five Fingers Butte, Wyoming, topographic quadrangle; 42 degrees 14 minutes 30.84 seconds north latitude and 108 degrees 23 minutes 31.5 seconds west longitude.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature -- 6.0 to 8.0 degrees C.
Particle-size control section (weighted averages)
Clay content -- 3 to 12 percent
Total rock fragments -- 35 to 50 percent
A horizon
Hue: 2.5Y or 10YR, dry or moist
Value: 4 or 5, dry or moist
Chroma: 3 or 4, dry or moist
Clay content: 10 to 17 percent
Rock fragments: 20 to 45 percent gravel
Reaction: pH 7.2 to 7.8
Bw horizon
Hue: 2.5Y or 10YR, dry or moist
Value: 4 or 5, dry or moist
Chroma: 3 or 4, dry or moist
Texture (less than 2 mm fraction): sandy loam, coarse sandy loam
Clay content: 10 to 18 percent
Rock fragments content: 20 to 40 percent gravel
Reaction: pH 7.2 to 7.6
Bk horizon
Hue: 2.5Y or 10YR, dry or moist
Value: 4 or 5, dry or moist
Chroma: 4 to 6, dry or moist
Texture (less than 2 mm fraction): sandy loam, loamy coarse sand
Clay content: 5 to 17 percent
Rock fragments content: 35 to 50 percent gravel
Calcium carbonate equivalent: 2 to 4 percent
Reaction: pH 7.5 to 8.0
BCk and C horizons
Hue: 2.5Y or 10YR, dry or moist
Value: 4 or 5, dry or moist
Chroma: 4 to 6, dry or moist
Texture (less than 2 mm fraction): coarse sand, loamy coarse sand
Clay content: 2 to 10 percent
Rock fragments content: 35 to 50 percent gravel
Calcium carbonate equivalent: 2 to 4 percent
Reaction: pH 7.4 to 8.0
C horizon
Hue: 2.5Y or 10YR, dry or moist
Value: 4 or 5, dry or moist dry
Chroma: 4 to 6, dry or moist
Texture (less than 2 mm fraction): coarse sand, loamy coarse sand
Clay content: 2 to 10 percent
Rock fragments: 35 to 50 percent gravel, 0 to 5 percent cobbles
Reaction: pH 7.2 to 7.6
COMPETING SERIES:
Birney (MT) -- soils have calcium carbonate equivalent greater than 5 percent in the Bk horizon
GEOGRAPHIC SETTING:
Landform -- hillslopes, fan remnants and strath terraces
Elevation -- 2,080 to 2,170 meters
Slope -- 1 to 30 percent
Parent material - slope alluvium and colluvium derived from conglomerate.
Climate -- long, cold winters; cool, moist springs; short, warm summers
Mean annual precipitation -- 225 to 325 mm with peak periods of precipitation occurring during the spring
Mean annual air temperature -- 5.0 to 7.0 degrees C.
Frost-free period -- 40 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat excessively to well drained, 15.0-150.0 um/sec.
USE AND VEGETATION: Scotty soils are primarily used for rangeland. The potential native vegetation is mainly birdfoot sage, spiny phlox, needle and thread, Indian ricegrass, and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Scotty soils are of small extent in southwestern Wyoming. MLRA 34A.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Sweetwater County, Wyoming, 2017. The name is derived from a local landmark.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon -- 0 to 9 cm (A horizon)
Cambic horizon -- 9 to 37 cm (Bw and Bk horizons)
Secondary calcium carbonate accumulations -- 22 to 70 cm (Bk and BCk horizons)
Particle-size control section -- 25 to 100 cm (part of the Bk, BCk and part of the C horizons)
Scotty soils have a frigid temperature regime and an ustic moisture regime and an aridic moisture subclass.
Taxonomic version: Twelfth edition, 2014
National Cooperative Soil Survey
U.S.A.