LOCATION GOLVA ND+MTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Typic Haplustolls
TYPICAL PEDON: Golva silt loam - under grassland. (Colors are for dry soil unless otherwise noted)
A--0 to 5 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure parting to moderate medium granular; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; neutral; gradual wavy boundary. (4 to 10 inches thick)
Bw1--5 to 15 inches; grayish brown (2.5Y 5/2) silt loam, very dark grayish brown (2.5Y 3/2) moist; moderate coarse and medium prismatic structure; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; slightly alkaline; gradual wavy boundary.
Bw2--15 to 21 inches; light brownish gray (2.5Y 6/2) silt loam, dark grayish brown (2.5Y 4/2) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; strong effervescence; moderately alkaline; clear wavy boundary. (Combined Bw horizons 7 to 22 inches thick)
Bk1--21 to 32 inches; pale yellow (2.5Y 7/4) silt loam, olive brown (2.5Y 4/4) moist; moderate coarse prismatic structure parting to weak medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; discontinuous thin pebble line at bottom of horizon; common masses of carbonates; violent effervescence; moderately alkaline; clear smooth boundary.
Bk2--32 to 40 inches; pale yellow (5Y 8/3) silt loam, olive (5Y 5/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common masses of carbonates; violent effervescence; moderately alkaline; abrupt wavy boundary. (Combined Bk horizons 6 to 34 inches thick)
C--40 to 60 inches; pale yellow (5Y 8/3) silt loam, olive (5Y 5/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; strong effervescence; moderately alkaline.
TYPE LOCATION: Slope County, North Dakota; about 12 miles east of Marmarth; 1,630 feet north and 2,000 feet west of the southeast corner, sec. 36, T. 133 N., R. 104 W. (440 feet east of road).
RANGE IN CHARACTERISTICS: The depth to carbonates ranges from 10 to 22 inches. The mollic epipedon is 7 to 16 inches thick and commonly includes part of the Bw horizon. The control section ranges from 18 to 30 percent clay. The depth to siltstone or silty shale is greater than 40 inches.
The A horizon has hue of 10YR or 2.5Y, value of 4 or 5, 2 or 3 moist, and chroma of 2 or 3. It commonly is silt loam, but includes loam and silty clay loam. It is neutral or slightly alkaline.
The Bw horizon has hue of 10YR or 2.5Y, value of 4 to 6, 3 to 5 moist, and chroma of 2 or 3. It is silt loam or silty clay loam. It is slightly alkaline or moderately alkaline. In some pedons the Bw1 horizon contains carbonates.
The Bk horizon has hue of 10YR, 2.5Y or 5Y, value of 6 to 8, 4 to 6 moist, and chroma of 2 to 4. It is silt loam or silty clay loam. It is moderately alkaline.
The C horizon has hue of 10YR, 2.5Y or 5Y, value of 5 to 8, 4 to 6 moist, and chroma of 2 to 4. It is silt loam, silty clay loam or loam. Some pedons have sandy loam or silty clay material between 40 and 60 inches depth. The C horizon is moderately alkaline.
COMPETING SERIES: These are the Amsterdam, Bryant, Omio, Peritsa, Sen and Temvik series. Amsterdam soils contain substantial amounts of volcanic glass shards and are in intermountain valleys. Bryant soils formed in reworked glaciolacustrine sediments or loess and commonly have rock fragments throughout. Omio, Peritsa and Sen soils have bedrock at depths of 20 to 40 inches. In addition, Peritsa soils have hues of 5YR or redder throughout. Temvik soils have glacial till 2C horizons.
GEOGRAPHIC SETTING: Golva soils are on fans and terraces, and in shallow concave swales. Slope gradients commonly average between 2 and 5 percent but range from 0 to 15 percent. The soils are formed in silty alluvium derived from local sedimentary beds. The climate is cool, semiarid. Mean annual air temperature ranges from 39 to 45 degrees F, and mean annual precipitation from 13 to 18 inches. Most of the moisture falls during spring and summer. Frost-free period ranges from 120 to 135 days and elevation ranges from 1650 to 3600 feet
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Sen soils and the Cabba and Chama soils. Sen and Chama are on higher lying slopes. Chama soils are moderately deep to soft bedrock. Cabba soils on steep slopes and ridge crests. They do not have a mollic epipedon and are shallow to soft bedrock.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is negligible to medium depending on slope. Permeability is moderate.
USE AND VEGETATION: Used mainly for small grains; some row crops, hay, and pasture. Native vegetation is mid and short prairie grasses, such as blue grama, green needlegrass, western wheatgrass, and some forbs.
DISTRIBUTION AND EXTENT: Western North Dakota, eastern Montana, possibly northwestern South Dakota. Moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Slope County, North Dakota, 1974.
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 (A and Bw1 horizons); cambic horizon - the zone from 15 to 21 inches (Bw2 horizon).