LOCATION TOMICHI COEstablished Series
TAXONOMIC CLASS: Sandy, mixed Ustic Haplocryolls
TYPICAL PEDON: Tomichi sandy loam, grassland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 10 inches, brown (7.5YR 5/2) sandy loam, dark brown (7.5YR 3/2) moist; moderate fine granular structure; soft, very friable; neutral; clear smooth boundary. (7 to 15 inches thick)
C--10 to 60 inches, very pale brown (10YR 7/3) gravelly sand, pale brown (10YR 6/3) moist; single grained; loose; 20 percent gravel; neutral. (Several feet thick)
TYPE LOCATION: Gunnison County, Colorado; SE1/4, SE1/4 sec. 9, T.14S., 82W.
RANGE IN CHARACTERISTICS: The Tomichi soils lack cambic horizons or characteristics of the mollic epipedon that are equivalent to cambic horizons. The mollic epipedon ranges from 7 to 15 inches thick. The soils typically are noncalcareous to depths of more than 60 inches but depth to uniformly calcareous material ranges from 40 to more than 60 inches. Base saturation ranges from 60 to 100 percent but typically is more than 80 percent. The fine earth in the control section is loamy sand or sand. Rock fragments range from 0 to 35 percent and are typically less than 3 inches in diameter. The A and C horizons range from slightly acid to mildly alkaline.
The A horizon has hue of 2.5Y through 7.5YR, value of 4 or 5 dry, 2 or 3 moist, and chroma of 1 through 3.
The C horizon has hue of 2.5Y through 7.5YR.
COMPETING SERIES: These are the Bangston and Koppes series. Bangston soils have mollic epipedons more than 16 inches thick. Koppes soils have a large proportion of medium, coarse and very coarse angular sand in the sand fraction and have base saturation of about 50 to 75 percent.
GEOGRAPHIC SETTING: The Tomichi soils are on terraces, glacial outwash plains, and on kames and eskers in glaciated country. Slope gradients typically range from 2 to about 15 percent. The soils formed in alluvial parent materials, glacial outwash, or coarse textured glacial deposits. At the type location the average annual precipitation is 20 inches. Mean annual temperature is 31 degrees F., and mean summer temperature is 52 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pierian and Tine soils. Pierian and Tine soils have more than 35 percent coarse fragments.
DRAINAGE AND PERMEABILITY: Well to somewhat excessively drained; slow runoff; rapid permeability.
USE AND VEGETATION: These soils are used principally as native pastureland. Native vegetation is mainly sagebrush and grasses.
DISTRIBUTION AND EXTENT: Mountain valleys of central Colorado. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Gunnison County, Colorado, 1974.
OSED scanned by SSQA. Last revised by state on 9/74.