LOCATION BLANYON CO+MTEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Ustertic Haplargids
TYPICAL PEDON: Blanyon silty clay loam - grassland. (Colors are for dry soil unless otherwise noted.)
A--0 to 4 inches; pinkish gray (7.5YR 6/2) silty clay loam, brown (7.5YR 4/2) moist; moderate fine granular structure; slightly hard, very friable, slightly sticky, slightly plastic; noncalcareous; neutral (pH 7.2); clear smooth boundary. (3 to 8 inches thick)
BA--4 to 10 inches; brown (7.5YR 5/2) silty clay loam, brown (7.5YR 4/2) moist; moderate medium prismatic structure parting to moderate fine subangular blocky; wide cracks between some peds when dry; slightly hard, very friable, moderately sticky and moderately plastic; peds are very hard; few faint clay films on faces of peds and discontinuous clay films lining root channels and pores; noncalcareous; neutral (pH 7.2); clear smooth boundary. (3 to 6 inches thick)
Bt--10 to 20 inches; light brown (7.5YR 6/3) silty clay, brown (7.5YR 4/3) moist; moderate coarse and medium prismatic structure parting to strong medium angular blocky; wide cracks between peds when dry; slightly hard, friable, moderately sticky and moderately plastic; peds are extremely hard, thin continuous wax-like coatings on faces of peds; common distinct clay films on faces of peds and lining pores; noncalcareous; slightly alkaline (pH 7.5); gradual smooth boundary. (6 to 31 inches thick)
BC--20 to 25 inches; light brown (7.5YR 6/3) silty clay, brown (7.5YR 4/3) moist; weak coarse prismatic structure parting to weak medium angular and subangular blocky; wide cracks between some peds when dry; hard, firm, moderately sticky and moderately plastic; peds are extremely hard; few faint clay films on some faces of peds and discontinuous clay films in pores and root channels; calcareous; moderately alkaline (pH 8.2); gradual smooth boundary. (3 to 10 inches thick)
Ck--25 to 60 inches; pinkish gray (7.5YR 6/2) silty clay, brown (7.5YR 4/2) moist; massive; extremely hard, firm, moderately sticky and moderately plastic; wide irregular cracks when dry; visible secondary calcium carbonate occurring as small concretions and in thin seams and streaks; amount of visible calcium carbonate decreases with increasing depth; calcareous; moderately alkaline (pH 8.4).
TYPE LOCATION: Montrose County, Colorado; approximately 900 feet north of the SW corner of Sec. 11, T. 49 N., R. 8 W.
RANGE IN CHARACTERISTICS: Depth to uniformly calcareous material normally ranges from 6 to 40 inches and is not shallower than the upper 2 inches of the Bt horizon. Depth to the base of the argillic horizon ranges from 12 to 40 inches. Depth to continuous subhorizons of visible secondary carbonate and/or sulfate ranges from 10 to 40 inches, but such horizons are not strong enough to qualify as calcic or gypsic horizons. ESP either remains constant or increases with increasing depth ranging from 0 to 15 percent in the solum but exceeding 15 percent in the Ck horizon in some pedons. The control section of some pedons has few faint mottles with chroma of more than 2 in both matrix and mottling. Rock fragments range from 0 to 15 percent by volume in a major part of the solum and C horizon above 40 inches and are mainly 1/2 to 10 inches in diameter.
The A horizon has hue of 5Y through 7.5YR, value of 5 through 7 dry, 3 through 6 moist, and chroma of 1 through 4. It is neutral or slightly alkaline.
The Bt horizon has hue of 5Y through 7.5YR, value of 5 through 7 dry, 4 through 6 moist, and chroma of 1 through 6. It is typically silty clay or silty clay loam but ranges in clay from 35 to 60 percent, silt from 15 to 55 percent, and sand from 5 to 45 percent with less than 15 percent being fine or coarser sand. This horizon is neutral or slightly alkaline.
The C horizon has hue of 5Y through 7.5YR. It is typically silty clay or silty clay loam but clay ranges from 35 to 60 percent, silt from 15 to 55 percent, and sand from 5 to 45 percent. This horizon is moderately or strongly alkaline. Calcium carbonate equivalent of the fine earth ranges from about 3 to 14 percent.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: The Blanyon soils are on gently to moderately sloping alluvial fans, terraces, and in drainageways. Slopes typically range from about 0 to 20 percent or more. The soils formed in thick, calcareous, moderately fine to fine textured materials derived principally from sedimentary bedrock. At the type location the mean annual precipitation is about 14 inches with peak periods of precipitation occurring in the spring and early summer months. Mean annual temperature is 41 degrees F, mean summer temperature is 46 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bostwick and Luhon soils. Bostwick soils have a mollic epipedon and are fine-loamy. Luhon soils are fine-loamy, lack an argillic horizon, and have a calcic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow to medium runoff; slow to moderate permeability.
USE AND VEGETATION: These soils are used as grazing land or as irrigated cropland. Native vegetation is sage, cactus, blue grama, and bluegrass.
DISTRIBUTION AND EXTENT: Western Colorado. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Delta-Montrose Area, Colorado, 1965.