Digital Data to Support Development of a Pesticide Management Plan for the Standing Rock Indian Reservation, Sioux County, North Dakota, and Corson County, South Dakota

Contents

Delineation of buried valleys

This line coverage contains information about the delineation of buried valleys within the Standing Rock Indian Reservation, Sioux County, North Dakota, and Corson County, South Dakota. The delineation of the buried valleys was included as part of the surficial geology map (Howells, 1982, fig. 5). According to the map credit for figure 5, the geology for Sioux County was based on soil maps prepared by the U.S. Bureau of Indian Affairs (1959), data collected by Randich (1975), and a geologic map by Carlson (1978). The geology for Corson County was based on soil maps prepared by the U.S. Bureau of Indian Affairs (1959) and unpublished maps of the U.S Soil Conservation Service, modified by test drilling and field reconnaissance.

Approximate western extent of glaciation

This line coverage contains information about the western limit of glaciation within the Standing Rock Indian Reservation, Sioux County, North Dakota, and Corson County, South Dakota. This information was included as part of the surficial geology map (Howells,1982, fig. 5).

The following description of the surficial geology is from Howells (1982). The surface geology, like the topography, has been strongly influenced by continental glaciation and by Pleistocene erosion on a land surface underlain by soft unconsolidated deposits of continental and marine shale and sandstone. The Standing Rock Indian Reservation is on the western margin of the midwestern area that was invaded by great ice sheets during the last million years. Though at most only 60 percent of the reservation apparently was covered by glacial ice, the effects of the glaciers were pervasive: not only did the ice sheets grind away the land surface in the areas that they invaded, but they also changed the courses of rivers and created a new river—the Missouri. In addition, changes in weather patterns associated with glaciation profoundly influenced streamflow and erosion in the area not reached by the ice sheets. Because the Standing Rock Indian Reservation was on the border of the glaciated region, much of the area is free of glacial deposits and most of the glacial deposits present are thin, discontinuous, and of negligible hydrologic importance.

Surficial geology

This polygon coverage contains information about the surficial geology for the area within the Standing Rock Indian Reservation, Sioux County, North Dakota, and Corson County, South Dakota. Identified units include: 1) alluvium, terrace, outwash, colluvium, eolian deposits, and buried-valley fill; 2) glacial till; 3) Fort Union Formation; 4) Hell Creek Formation; 5) Fox Hills Formation; and 6) Pierre Shale. This data set is the digital version of the surficial geology depicted in Howells (1982, fig. 5).

The following definitions were used for the geologic units.

• Alluvium, terrace, outwash, colluvium, eolian deposits, and buried-valley fill—The small scale prevents differentiating these deposits on this map. Alluvium is water-laid material deposited on flood plains and valleys of rivers and streams. Most of the material is clay, silt, and fine sand but there is some coarser material. Terraces are older alluvial deposits that now are above the level of the flood plain because the stream has eroded its valley deeper since deposition of the sediment. Outwash was deposited in streams and lakes formed by melting glaciers. Maximum thickness of alluvium or outwash is less than 120 feet; of terraces, more than 50 feet. Colluvium is landslide and slumpage detritus, commonly deposited at the foot of the steep slopes. The material usually is fragments of shale, silt, and sand, but may include gravel or sandstone cobbles from terraces or sandstone beds capping higher benches or buttes. Deposits may exceed 100 feet in thickness. Eolian deposits are windblown material, mostly silt and fine sand, but include some clay and, in some areas, much medium sand. Deposits are as much as 20 feet thick, but a thin coating, as little as a fraction of an inch thick, overlies most of the area. Buried valley fill is mostly glacial stream and outwash deposits but includes some till. The material is mostly moderately sorted gravel, sand, silt, and clay. Maximum thickness locally exceeds 300 feet. Quaternary Period.
• Glacial till—Deposited beneath or at the margins of the continental glaciers. The material is a heterogeneous mixture of sizes from clay to boulders. Maximum thickness probably is less than 40 feet. Quaternary Period.
• Fort Union Formation—Gray to buff interbedded very fine to medium-grained sandstone, siltstone, claystone, silty clay, and shale; thin carbonaceous or lignitic beds near the base. Contains three widely persistent sandstone beds. Maximum thickness is greater than 400 feet. Tertiary Period.
• Hell Creek Formation—Somber-colored, soft clay shale and buff to gray, weakly cemented, coarse- to fine-grained sandstone and siltstone. Contains lignitic lenses and thin, black carbonaceous shale beds. Maximum thickness may be greater than 400 feet. Cretaceous Period.
• Fox Hills Formation—Dark- to light-gray silty and sandy clay, clayey silt, and very fine-grained sandstone; overlain, in Corson County, by dark-gray to yellowish-orange, weakly cemented, very fine-grained sandstone. The upper part of the formation is a thinly bedded sequence of clay, silt, and sand, that contains discontinuous beds of silica-cemented very fine-grained sandstone. Contacts between the Hell Creek and Pierre Shale are gradational. Maximum thickness is about 400 feet. Cretaceous Period.
• Pierre Shale—Gray to brown, tough, gummy to friable shale, noncalcareous to highly calcareous, contains widely persistent zones of bentonite and of iron manganese or limestone concretions. Where exposed at the surface, the top few feet commonly is weathered. Maximum thickness is about 1,400 feet. Cretaceous Period.

Availability of shallow ground-water resources

This polygon coverage contains information about the probability of obtaining a water supply within the Standing Rock Indian Reservation, Sioux County, North Dakota, and Corson County, South Dakota. This coverage is based on information in Howells (1982, fig. 6).

The possibility of obtaining adequate supplies of good quality water from surficial deposits generally is limited to bedrock formations overlying the Pierre Shale where their total thickness is at least 150 feet, to four buried glacial valleys in eastern Sioux County, and to alluvium along Cedar Creek and the Cannonball and Missouri Rivers. In a few places, adequate supplies of stock or domestic water may be found in alluvium along the Grand River and in a few terraces (Howells, 1982).

Identified units include: 1) Excellent—Well yields may range from 500 to 1,000 gallons per minute. Dissolved-solids concentration probably is less than 1,600 milligrams per liter; 2) Very good—May range from 200 to 500 gallons per minute. Dissolved-solids concentration probably is less than 1,600 milligrams per liter; 3) Good—Well yields range from 10 to 200 gallons per minute. Dissolved-solids concentration is probably less than 1,600 milligrams per liter; 4) Good to fair—Well yields range from 2 to 10 gallons per minute, locally may be larger; 5) Fair—Well yields may range from 2 to 10 gallons per minute. Greater chance that any water found will be of poor quality; 6) Fair to poor—Locally possible to obtain well yields of 1 to 5 gallons per minute. Water is commonly of poor quality; and 7) Very poor—Low probability of obtaining water. Any water found is likely to be of very poor quality.

Selected References:

Carlson, C.G., 1982, Geology of Grant and Sioux Counties, North Dakota: North Dakota State Water Commission County Ground-Water Studies 24, pt. 1, and North Dakota Geological Survey Bulletin 67, pt. 1.

Howells, L.W., 1982, Geohydrology of the Standing Rock Indian Reservation, North and South Dakota: U.S. Geological Survey Hydrologic Investigations Atlas HA-644, 5 sheets.

Randich, P.G., 1979, Ground-water resources of Grant and Sioux Counties, North Dakota: North Dakota State Water Commission County Ground-Water Studies 24, pt. II, and North Dakota Geological Survey Bulletin 67, pt. II, 303 p.

Schaap, B.D., 2004, Compilation of data to support development of a pesticide management plan by the Yankton Sioux Tribe, Charles Mix County, South Dakota: U.S. Geological Survey Open-File Report 2004-1032, 20 p. (CD-ROM included). (https://pubs.water.usgs.gov/ofr2004-1032)

Thompson, R.F, 2002, Compilation of data to support development of a pesticide management plan by the Sisseton-Wahpeton Sioux Tribe, South and North Dakota: U.S. Geological Survey Open-File Report 02-381, 25 p. (2 CD-ROMs included).

U.S. Bureau of Indian Affairs, 1959, Combined soil and range survey, Standing Rock Reservation, North and South Dakota: Missouri River Investigations Project Report 146, 71 p., maps.