LOCATION ROLETTE NDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Alfic Vertic Argiudolls
TYPICAL PEDON: Rolette silty clay loam - on an east-facing plane or slightly convex slope of 1 percent under native hardwoods and grass. (Colors are for moist soil unless otherwise stated. When described the soil was moist throughout.)
0e--2 to 0 inches; very dark brown (10YR 2/2) partly decomposed organic matter mostly of tree and shrub leaves; very friable; many fine roots; abrupt smooth boundary. (0 to 3 inches thick)
A1--0 to 6 inches; black (10YR 2/1) silty clay loam, dark gray and gray (10YR 4/1 and 10YR 5/1) dry; weak fine subangular blocky structure parting to moderate very fine granular; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; many fine pores; neutral; clear smooth boundary.
A2--6 to 15 inches; very dark gray (10YR 3/1) silty clay loam, dark gray and gray (10YR 4/1 and 10YR 5/1) dry; weak fine subangular blocky structure parting to strong fine granular; very hard, friable, sticky and plastic; common fine and coarse roots; many fine pores; faces of some peds have gray (10YR 6/1) uncoated sand and silt grains; neutral; gradual smooth boundary. (Combined A horizons 5 to 22 inches thick)
B/E--15 to 18 inches; very dark gray (10YR 3/1) (Bt and E) silty clay loam, gray (10YR 5/1) (Bt) and light gray (10YR 6/1) (E) dry; moderate fine and very fine subangular blocky structure; very hard, friable, sticky and plastic; common fine roots; common fine pores; neutral; gradual wavy boundary. (2 to 5 inches thick)
Bt1--18 to 22 inches; dark grayish brown (2.5Y 4/2) silty clay, light brownish gray and light gray (2.5Y 6/2 and 2.5Y 7/2) dry; moderate medium and fine prismatic structure parting to strong fine subangular blocky; extremely hard, very firm, very sticky and very plastic; few fine and coarse roots; few fine and coarse pores; faces of peds coated with faint black (10YR 2/1) moist clay films; white (2.5Y 8/2) dry uncoated silt grains on faces of peds; neutral; gradual smooth boundary.
Bt2--22 to 38 inches; dark grayish brown (2.5Y 4/2) silty clay, light brownish gray (2.5Y 6/2) dry; strong medium and fine prismatic structure parting to strong medium subangular blocky; extremely hard, very firm, very sticky and very plastic; few fine roots; few fine pores; faint clay films on faces of peds; neutral; gradual wavy boundary. (Combined Bt horizons 11 to 26 inches thick)
C--38 to 60 inches; olive (5Y 4/3) silty clay, light olive gray (5Y 6/2) dry; many fine prominent strong brown (7.5YR 5/8) moist and fine faint olive (5Y 5/3) moist mottles; moderate medium angular blocky structure; extremely hard, very firm, very sticky and very plastic; few fine pores; soft shale particles in the lower part; slight effervescence; slightly alkaline.
TYPE LOCATION: Pembina County, North Dakota; about 1 1/2 miles north and 1 mile west of Concrete; 2590 feet south and 90 feet east of the northwest corner, sec. 18, T. 161 N., R. 56 W.
RANGE IN CHARACTERISTICS: The depth to carbonates ranges from 20 to more than 50 inches.
The A horizon has value of 3 to 5 and 2 or 3 moist. It is silty clay, clay loam or silty clay loam. It is slightly acid or neutral. Some pedons have an E/B horizon.
The Bt horizon has hue of 10YR, 2.5Y, or 5Y, value of 4 to 7 and 3 or 4 moist, and chroma of 1 to 3. It is silty clay or clay. It has prismatic and angular or subangular blocky structure. It is neutral. Some pedons have Bk or BC horizons with textures of clay loam, silty clay loam or silty clay.
The C horizon has hue of 2.5Y or 5Y, value of 5 to 7 and 4 to 6 moist, and chroma of 1 to 3. It is silty clay, clay, clay loam or silty clay loam. It is slightly alkaline or moderately alkaline. The C horizon is varved in some pedon and has thin stratifications of coarser textures in other pedons.
COMPETING SERIES: This is the Olga series. Olga soils are more acid. In addition, they have formed in glacial till and contain coarse fragments.
GEOGRAPHIC SETTING: Rolette soils are on glacial lake or delta plains. Slope gradients are 0 to 9 percent. The soil formed in calcareous clayey glaciolacustrine deposits. The mean annual air temperature ranges from about 37 to 40 degrees F, and mean annual precipitation from 15 to 22 inches. Most of the moisture falls during spring and summer.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Olga soils and the Barnes, Bottineau, Buse, Brantford, Kelvin, Nutley, Rolla, Vang, Walsh and Waukon soils. Olga soils are on nearby sloping and hilly valley sides and uplands. Barnes, Bottineau, Buse and Waukon soils are on nearby till plains and are fine-loamy. In addition, Waukon soils do not have mollic epipedons. Brantford and Vang soils have formed in nearby outwash sandy-skeletal. Kelvin soils formed in nearby till and do not have mollic epipedons. Nutley soils have formed on nearby glaciolacustrine plains and do not have argillic horizons. Rolla soils are on nearby glaciolacustrine plains and do not have mollic epipedons. Walsh soils have formed in nearby glacial outwash containing a high percentage of shale particles and are fine-loamy.
DRAINAGE AND PERMEABILITY: Moderately well drained. Runoff is negligible to medium depending on slope. Permeability is moderately slow.
USE AND VEGETATION: Soils are cropped to small grains, hay, and pasture. Native vegetation is elm, oak, aspen, green ash, and an understory of shrubs and grasses.
DISTRIBUTION AND EXTENT: Northern and northeastern North Dakota in the Pembina delta. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Pembina County, North Dakota, 1972.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 15 inches (A1 and A2 horizons); argillic horizon - the zone from 18 to 38 inches (Bt1 and Bt2 horizons); tonguing and interfingering of albic material in the argillic horizon (B/E and Bt1 horizons).