LOCATION CEBONE COEstablished Series
TAXONOMIC CLASS: Fine, smectitic Alfic Argicryolls
TYPICAL PEDON: Cebone loam - timberland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 13 inches; dark grayish brown (10YR 4/2) loam, very dark brown (10YR 2/2) moist; strong fine crumb and granular structure; soft, very friable; neutral (pH 6.6); clear smooth boundary. (7 to 15 inches thick)
A2--13 to 19 inches; pinkish gray (7.5YR 7/2) fine sandy loam, brown (7.5YR 5/4) moist; moderate thick platy structure that parts to moderate fine granules; soft, very friable; neutral (pH 6.6); clear wavy boundary. (3 to 8 inches thick)
A&B--19 to 24 inches; pinkish gray (7.5YR 7/2) light clay loam, brown (7.5YR 5/4) moist; common reddish brown (5YR 5/4) seams and nodules of more clayey material, reddish brown (5YR 5/4) seams and nodules of more clayey material, reddish brown (5YR 4/4) moist; moderate fine subangular blocky structure; slightly hard and very hard, very friable; thin glossy patches on some face of peds; neutral (pH 6.6); gradual wavy boundary. (4 to 8 inches thick)
B2t--24 to 34 inches; mixed reddish brown (5YR 5/4) brown (7.5YR 5/4) clay, reddish brown (5YR 4/4) and brown (7.5YR 4/4) moist; crushed and mixed colors are brown (7.5YR 5/4) and dark brown (7.5YR 4/4) moist; moderate coarse subangular blocky structure; hard and extremely hard, very friable; thick continuous wax-like coatings on faces of peds and in root channels; neutral (pH 6.6); gradual wavy boundary. (6 to 23 inches thick)
B3--34 to 38 inches; mixed light yellowish brown (2.5Y 6/4) and brown (7.5YR 5/4) clay, light olive brown (2.5Y 5/4) and dark brown (7.5YR 4/4) moist; mixed and crushed colors are yellowish brown (10YR 5/4) and dark yellowish brown (10YR 4/4) moist; weak coarse subangular blocky structure; very hard and extremely hard, firm; thin nearly continuous glossy coatings on faces of peds; wax-like coatings in root channels; neutral (pH 6.5); gradual wavy boundary. (0 to 6 inches thick)
IIC--38 to 40 inches; noncalcareous shale and loamstone.
TYPE LOCATION: Mesa County, Colorado; NW 1/4 of Sec. 7, T. 14 S., R. 10 W.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 7 to 15 inches thick and the solum ranges from 20 to 40 inches thick. Depth to the paralithic contact ranges from 20 to 40 inches. The estimated organic carbon content of the mollic epipedon ranges from .6 to 1.5 percent and decreases uniformly with depth. Typically, conductivity is less than 1 millimho, calcium carbonate equivalent less than 1 percent, and exchangeable sodium percentage less than 1. The soil is 80 to 100 percent base-saturated. Cation exchange capacity ranges from 60 to 90 milliequivalents per hundred grams of clay. Rock fragments range from 0 to 15 percent, but are commonly less than 10 percent. Mean annual soil temperature ranges from 32 to 47 degrees F and mean summer soil temperature ranges from 45 to 60 degrees F.
The A1 horizon has hue of 2.5Y or 10YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 1 through 3. It is slightly acid or neutral (pH 6.1 to 7.3). Typically, the horizon has crumb or granular primary structure but is weak platy in the lower portion or weak subangular blocky throughout in some pedons. It is soft to slightly hard.
The A2 horizon has hue of 10YR or 7.5YR, value of 6 through 8 dry, 4 through 6 moist, and chroma of 2 through 4. It is slightly acid or neutral (pH 6.1 to 7.3). Typically, the horizon has platy primary structure but it has subangular blocky or granular structure in some pedons. It is soft to slightly hard.
The B2t horizon has hue of 2.5Y through 5YR, value of 5 or 6 dry, 4 or 5 moist, and chroma of 3 through 5. After crushing and mixing, the horizon has hue of 7.5YR or 10YR. (The range in color is wide due to the variegated nature of the parent sediments.) It is slightly acid to neutral (pH 6.1 to 7.3). The B2t horizon usually had medium or coarse angular blocky structure. It is typically clay but content of clay ranges from 35 to 50 percent, silt from 10 to 40 percent, and sand from 15 to 50 percent. This horizon has oriented clay films on faces of peds, in root channels and in soil pores.
The IIC horizon has hue of 2.5Y through 5YR.
COMPETING SERIES: These are the Cebolia, Mord, and Powderhorn series. Cebolia soils have an abrupt increase in clay or more than 20 percent between the A and B2t horizons. Mord and Powderhorn soils lack a paralithic contact above a depth of 40 inches.
GEOGRAPHIC SETTING: These soils are on gently sloping to steeply sloping upland mountainsides and ridge crests, typically at elevations in excess of 8,000 feet. The soils formed in sediments weathered from underlying multicolored Morrison shales and interbedded sandstones. Slope gradients range from 2 to 45 percent. At the type location, average annual precipitation is 20 inches with peak periods of precipitation occurring during the spring and early summer months. Average annual temperature is 40 degrees F and mean summer temperature is 56 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gateway and Mayflower soils. Gateway soils lack a mollic epipedon. Mayflower soils lack an albic horizon and have a mollic epipedon more than 16 inches thick.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; slow permeability.
USE AND VEGETATION: These soils are used principally as native pastureland or for forestry purposes. Principal native plants are poplar, spruce, some ponderosa pine, and a thick understory cover of grasses and shrubs.
DISTRIBUTION AND EXTENT: The western slope of Colorado. This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Lower Colorado Area, Colorado, 1970.
REMARKS: Last updated by the state 11/72.