LOCATION TUFFIT             MT

Established Series
Rev. BHW
03/2002

TUFFIT SERIES

The Tuffit series includes dark moderately fine Solonetz soils of the glacial lake and stream terraces and gentle fan slopes in intermountain valleys in the Northern Rocky Mountains. Their parent materials are derived from gray, green and reddish argillites of the Belt geological formation. These soils occupy nearly flat, undulating and slightly depressed positions, and, in the lower places, receive some runoff from associated higher-lying soils. They differ from the Demers soils in that they have darker surface soils and heavier surface and upper subsoil layers. They are not so thoroughly leached of their lime carbonates in the upper part of their solum as Demers soils.

TAXONOMIC CLASS: Fine, mixed, superactive, frigid Typic Natrustolls

TYPICAL PEDON: Tuffit silty clay loam.

A1--0 to 4 inches; dark gray (10YR 4.4/1) dry; to very dark brown (10YR 2/2) moist; silty clay loam; granular; slightly alkaline reaction; calcareous in places; (pH about 7.5) (Soiltex test). (3 to 7 inches thick)

B2--4 to 12 inches; gray (10YR 5/1) dry; to very dark grayish-brown (10YR 3/2) moist; blocky or columnar silty clay; hard when dry; plastic when moist; very strongly alkaline reaction; calcareous as a rule; (pH about 9). (6 to 10 inches thick)

B3ca--12 to 29 inches; very pale brown (10YR 7/3) dry; to pale brown (10YR 6/3) moist; silt loam; irregular weak blocky structure; moderately compact and hard when dry; friable when moist; calcareous; (pH 9). (12 to 18 inches thick)

Cca--29 to 48 inches; very pale brown (10YR 8/4) dry; to pale brown (10YR 6/3) moist; silty very fine sandy loam; friable, no definite structure; slightly to medium alkaline reaction; calcareous. (14 to 20 inches thick)

CD-- 48 + inches; pale yellow, gray or very pale brown stratified silty to sandy parent alluvium. Range in thickness is several feet.

TYPE LOCATION: NE1/4 of NE1/4 of NW1/4 Sec. 20, T.27N., R.20W.

RANGE IN CHARACTERISTICS: Within areas of these soils are soils in all stages of salinization and Solonetz development. Little degradation of the clays, however, is apparent. Bare or slick "blowout" spots common to Solonetz soils in higher better drained positions are rare in these soils. Areas of these soils adjacent to or contiguous with till uplands may be underlain by till at a depth of 2 to 4 feet.

GEOGRAPHIC SETTING: Nearly level to undulating.

DRAINAGE AND PERMEABILITY: Runoff is low or lacking; the soils are slowly permeable above the friable substratum; small areas are temporarily ponded after heavy rains by runoff from higher ground.

USE AND VEGETATION: Wheat following summer fallow is the principal crop. Yields are generally low except in years of favorable distributed rainfall. Part of the land remains in pasture. Grasses of several species including saltgrass.

DISTRIBUTION AND EXTENT: Western Montana.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Upper Flathead Valley Area, Montana, 1957. The name is taken from a camp on a nearby lake in Lake County, Montana.

REMARKS: Prepared for the final field review and correlation of Upper Flathead Valley Area, Montana.

OSED scanned by SSQA. Last revised by state on 4/57.

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National Cooperative Soil Survey
U.S.A.