LOCATION LEAVITT WY+CO MTEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive Ustic Argicryolls
TYPICAL PEDON: Leavitt silt loam-rangeland. (Colors are for dry soil unless otherwise stated.)
A--0 to 7 inches; dark gray (10YR 4/1) silt loam, black (10YR 2/1) moist; strong medium granular structure; slightly hard, very friable, slightly sticky and nonplastic; many fine, medium, and very fine roots; neutral (pH 7.0); clear smooth boundary. (6 to 8 inches thick)
Bt1--7 to 12 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; strong very fine subangular blocky structure; hard, very friable, moderately sticky and slightly plastic; many fine, very fine, and medium roots; many prominent clay films on faces of peds; 5 percent rounded gravel; neutral (pH 6.8); clear smooth boundary. (4 to 8 inches thick)
Bt2--12 to 29 inches; brown (7.5YR 5/2) clay loam, brown (7.5YR 4/2) moist; moderate medium subangular blocky structure; hard, very friable, moderately sticky and moderately plastic; common fine and medium roots; many prominent clay films on faces of peds and in pores; 5 percent rounded gravel; neutral (pH 6.8); gradual smooth boundary. (7 to 24 inches thick)
Btk--29 to 38 inches; light brown (7.5YR 6/3) clay loam, brown (7.5YR 5/3) moist; weak coarse subangular blocky structure; hard, friable, moderately sticky and moderately plastic; few fine and medium roots; common distinct clay films on faces of peds and in root channels and pores; slightly effervescent matrix, strongly effervescent near calcium carbonate masses and filaments; 10 percent rounded gravel; moderately alkaline (pH 8.0); gradual smooth boundary. (5 to 10 inches thick)
Bk--38 to 60 inches; light brown (7.5YR 6/3) loam, brown (7.5YR 5/3) moist; massive; hard, friable, slightly sticky and slightly plastic; violently effervescent, calcium carbonate as common soft masses and thin pendants on rock fragments; 10 percent rounded gravel; moderately alkaline (pH 8.2)
TYPE LOCATION: Uinta County, Wyoming; approximately 1,055 feet east and 1,680 feet north of the SW corner of sec. 32, T. 13 N., R. 115 W. 41 degrees 3 minutes 32 seconds north latitude and 110 degrees 24 minutes 30 seconds west longitude.
RANGE IN CHARACTERISTICS: The mollic epipedon is 7 to 15 inches thick. Organic carbon in the epipedon ranges from .8 to 3 percent and decreases regularly with depth. Base saturation is 90 to 100 percent. Rock fragments range from 0 to 15 percent throughout. Some pedons have stones dominating, but, typically, the coarse fragments are gravel. The mean annual soil temperature is 32 to 44 degrees F., and the mean summer soil temperature is 40 to 55 degrees F.
The A horizon has hue of 2.5Y through 7.5YR, value of 3 through 5 dry, 2 or 3 moist, and chroma of 1 through 3. Reaction is slightly acid through slightly alkaline.
The Bt horizon has hue of 2.5Y through 5YR, value of 4 through 6 dry, 3 through 5 moist, and chroma of 1 through 4. When hue is redder than 7.5YR, color is not lithochromic and is confined to the horizons of maximum weathering. Texture is clay loam, loam, or silty clay loam with 18 to 35 percent clay and more than 15 but less than 35 percent fine or coarser sand. The upper part of the argillic horizon is typically part of the mollic epipedon. Reaction is slightly acid through slightly alkaline.
The Btk horizon has hue of 2.5Y through 7.5YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 2 through 4. Texture is clay loam, loam, silt loam, sandy clay loam, or silty clay loam with 18 to 35 percent clay and more than 15 but less than 35 percent fine or coarser sand. Carbonates range from 2 to 8 percent. EC is 0 to 4 mmhos. Reaction is slightly or moderately alkaline.
The Bk horizon has hue of 2.5Y through 7.5YR, value of 6 or 7 dry, 5 or 6 moist, and chroma of 2 through 4. Texture is loam, clay loam, or sandy clay loam. Carbonates range from 4 to 15 percent when averaged. Inconsistent accumulations of carbonates may exceed 15 percent but are discontinuous throughout the pedon. EC is 0 to 4 mmhos. Reaction is moderately or strongly alkaline.
COMPETING SERIES: These are the Amsden, Barbarela, Cific, Coldspring, Croftshaw, Dewville, Gelkie, Highrye, Hooligan, Inchau, Kezar, Lucky, Lymanson, Miracle, Monaberg, Morset, Oro Fino, Passcreek, Rainbolt, Tripit, Wellsville, Woosley, Youga, and Zade series. Amsden, Coldspring, Miracle, Rainbolt, and Tripit soils have hue of 5YR or redder in the Bt horizon. Barbarela, Cific, Inchau, Kezar, Lucky, Lymanson, Miracle, Passcreek, Rainbolt, Tripit, Woosley, and Zade soils have bedrock above a depth of 40 inches. Dewville, Gelkie, Kezar, Lucky, Oro Fino, Rainbolt and Slacks soils have more than 35 percent fine or coarser sand in the Bt horizon. Croftshaw, Highrye, Hooligan, Monaberg, and Youga soils are noncalcareous. Wellsville soils have 15 to 35 percent coarse fragments in the control section. Morset soils have a calcic horizon.
GEOGRAPHIC SETTING: Leavitt soils are on relict fan aprons, coalescing fans, terraces, hills, mountain slopes and valley-filling sideslopes. These soils formed in alluvium and alpine till derived primarily from crystalline and sedimentary rock. Slopes are 0 to 55 percent. Elevations are 6,000 to 9,500 feet. In Montana elevation is as low as 4800 feet on north slopes. The mean annual precipitation ranges from 10 to 25 inches, and the mean annual air temperature ranges from 30 to 42 degrees F. The frost-free season is less than 60 days. Frost can occur at any time at the higher elevations.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Lymanson, Troutdale, and Woosley series and the Leavittville soils. Leavittville soils have overthickened mollic epipedons.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Rangeland, wildlife habitat, and recreation. Native vegetation consists of Idaho fescue, thickspike wheatgrass, spike fescue, Canby bluegrass, antelope bitterbrush, and big sagebrush.
DISTRIBUTION AND EXTENT: Mountains of Wyoming, Colorado and Montana. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Uinta County, Wyoming; 1934.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 12 inches (A,Bt1)
Argillic horizon - 12 to 38 inches (Bt1,Bt2,Btk)
Horizons of secondary carbonate accumulation - 29 to 60 inches (Btk, Bk)
SIR - WY1166