Todd/Mellette Counties Study
This is an investigation of the geology and water resources of a two county area in south central South Dakota. The stratigraphy, sedimentology, and surficial geology are the main areas of emphasis. Surface deposits include:
- Miocene and Pleistocene sand dunes
- Miocene Ogallala Group sands and silts
- Oligocene Arikaree Group siltstones
- Oligocene and Eocene White River Group claystones and late Cretaceous Pierre Shale
Shallow ground water resources are often of exceptionally good quality.