LOCATION WHITEACORN WY
Tentative Series
Rev. DMM-DJP-RJS
02/2016
WHITEACORN SERIES
The WHITEACORN series consists of very deep, well drained soils that formed in alluvium or slope alluvium derived from granite. These soils are on eroded fan remnants and alluvial flats. Slopes are 1 to 20 percent. Mean annual precipitation is about 425 mm, and mean annual air temperature is about 1.2 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Inceptic Haplocryalfs
TYPICAL PEDON: Whiteacorn sandy loam, in rangeland (colors are for dry soil unless otherwise noted).
A--0 to 8 cm; brown (10YR 4/3) sandy loam, dark brown (10YR 3/3), moist; weak fine granular structure; very friable, soft, slightly sticky, slightly plastic; many very fine and fine roots; many fine interstitial pores; 13 percent gravel; neutral (pH 7.0); clear smooth boundary. (5 to 14 cm thick).
Bt--8 to 36 cm; yellowish brown (10YR 5/4) sandy clay loam, dark yellowish brown (10YR 4/4), moist; moderate fine subangular blocky structure; friable, slightly hard, slightly sticky, slightly plastic; many fine and few medium roots; many fine tubular pores; 2 percent faint clay bridges between sand grains; 13 percent gravel; neutral (pH 7.0); clear smooth boundary. (15 to 35 cm thick).
C1--36 to 60 cm; brown (10YR 5/3) very gravelly sandy loam, brown (10YR 4/3), moist; massive; friable, slightly hard, nonsticky, nonplastic; many fine roots; many fine interstitial pores; 40 percent gravel, 5 percent cobbles; neutral (pH 7.0). (5 to 40 cm thick).
C2--60 to 200 cm; light yellowish brown (2.5Y 6/3) very gravelly loamy sand, light olive brown (2.5Y 5/3), moist; massive; loose, nonsticky, nonplastic; few fine roots; many fine interstitial pores; 40 percent gravel, 10 percent cobbles; neutral (pH 7.0).
TYPE LOCATION: Sublette County, Wyoming; USGS Sweetwater Needles, Wyoming topographic quadrangle; 42 degrees 30 minutes 3.60 seconds north latitude and 109 degrees 4 minutes 49.10 seconds west longitude.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 1.3 to 3.7 degrees C.
Ochric epipedon thickness - 5 to 14 cm
Depth to argillic horizon - 5 to 14 cm
A horizon
Hue: 2.5Y or 10YR; dry or moist
Value: 3 or 4 dry; 2 or 3 moist
Chroma: 2 or 3; dry or moist
Texture: sandy loam, coarse sandy loam
Clay content: 10 to 20 percent
Rock fragments: 5 to 25 percent--5 to 25 percent gravel, 0 to 5 percent cobbles
Reaction: pH 6.4 to 7.0
Bt horizon
Hue: 2.5Y or 10YR; dry or moist
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 3 or 4; dry or moist
Clay content: 20 to 26 percent
Rock fragments: 5 to 35 percent--5 to 30 percent gravel, 0 to 5 percent cobbles
Reaction: pH 6.4 to 7.0
C1 horizon
Hue: 2.5Y or 10YR; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4; dry or moist
Texture: coarse sandy loam, sandy loam, sandy clay loam
Clay content: 8 to 21 percent
Rock fragments: 35 to 55 percent--35 to 50 percent gravel, 0 to 15 percent cobbles
Reaction: pH 6.6 to 7.3
C2 horizon
Hue: 2.5Y or 10YR; dry or moist
Value: 5 or 6 dry; 4 or 5 moist
Chroma: 3 or 4; dry or moist
Texture: loamy coarse sand, loamy sand
Clay content: 2 to 7 percent
Rock fragments: 35 to 50 percent--35 to 50 percent gravel, 0 to 15 percent cobbles
Reaction: pH 6.6 to 7.3
COMPETING SERIES:
Cranbay (UT) - have a diagnostic calcic horizon
Swapps (UT) - are moderately deep to a lithic contact
GEOGRAPHIC SETTING:
Landform - eroded fan remnants and alluvial flats
Elevation - 2,375 to 2,560 meters.
Slope - 1 to 20 percent.
Parent material - alluvium and/or slope alluvium derived from granite.
Climate - long, cold winters; cool, moist springs; short, cool summers.
Mean annual precipitation - 375 to 475 mm with peak periods of precipitation occurring during the spring.
Mean annual air temperature - 0.3 to 2.7 degrees C.
Frost-free period - 15 to 45 days.
GEOGRAPHICALLY ASSOCIATED SOILS: None listed.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained, Ksat in the particle-size control section ranges 5.0-15.0 um/sec and 15-150 um/sec below.
USE AND VEGETATION: Whiteacorn soils are primarily used for rangeland. The potential native vegetation is mountain big sagebrush, early sagebrush, Letterman's needlegrass, Sandberg bluegrass, Idaho fescue, western wheatgrass and bluebunch wheatgrass.
DISTRIBUTION AND EXTENT: Whiteacorn soils are of small extent in southwestern Wyoming. MLRA 46.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES PROPOSED: Sublette County, Wyoming, 2016. Whiteacorn series name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 8 cm (A horizon)
Argillic horizon - 8 to 36 cm (Bt horizon)
Particle-size control section - 8 to 36 cm (Bt horizon)
Whiteacorn soils have a cryic temperature regime and an ustic moisture regime.
National Cooperative Soil Survey
U.S.A.