Stratigraphy and history of the Sakakawea Sequence, south-central North Dakota

• Main Author: Bickley, William B., Jr.
• Format: Text
• Language: unknown
• Published: UND Scholarly Commons 1972
• Subjects: Geology > North Dakota > Emmons County; Geology; Stratigraphic > Pleistocene; Hudson Bay; Hudson; Riverdale; Ice; permafrost; Tundra
• Online Access: https://commons.und.edu/theses/22; https://commons.und.edu/context/theses/article/1021/viewcontent/Bickley__Willam_B._Doc_Diss_1972.pdf; https://commons.und.edu/context/theses/article/1021/filename/0/type/additional/viewcontent/Bickley_1972_Plate.zip

The Sakakawea Sequence (Pleistocene) in North Dakota contains six formations that make up the Coleharbor Group (Pleistocene). The Braddock Formation (Wisconsinan) is mainly glacial sediment. The Emmons Formation (late Wisconsinan) is mainly glacial sediment. The Four Bears Formation (Wisconsinan) is mainly either fluvial or lacustrine sediment. The Coteau Formation (Holocene) is mostly fluvial, colluvial, or slough sediment. The Denbigh Formation (Holocene) is mostly eolian sediment. The Oahe Formation (late Wisconsinan and Holocene) is mostly eolian sediment (loess) The Oahe Formation is divided into three members: the Mallard Island (late Wisconsinan), Aggie Brown (latest Wisconsinan to earliest Holocene), and Riverdale (middle and late Holocene) Members. During preglacial time major rivers flowed toward Hudson Bay. With the initiation of glaciation, ice blocked the rivers and forced them to flow southward. During the Pleistocene at least four major glaciations occurred. The Dunn Glaciation was pre-Wisconsinan that Verone Glaciation was post Dunn and pre-Napoleon, the Napoleon Glaciation was early Wisconsinan (?), and the Lostwood Glaciation was late Wisconsinan. Three phases (Cattail Creekt Zeeland, and Long Lake) are recognized within the Lostwood Glaciation~ The Cattail Creek was an early advance of the Lostwood Glaciation. The Zeeland and Long Lake Phases were later advances; they may have been contemporaneous. Numerous tundra polygons indicate permafrost conditions existed at the beginning of the Lostwood Glaciation. Polygons occur on all but the youngest glacial surfaces (Zeeland and Long Lake). Lakes Standing Rock and McKenzie were formed when the Lostwood ice dammed the Missouri River. Lake McKenzie was formed when ice of' the Cattail Creek Phase blocked the flow of the Missouri River in the Strasburg Channel. Lake Standing Rock probably formed when ice blocked the Missouri River in north-central South Dakota. In postglacial time, more detailed evidence allows reconstruction of the history of hillslope ...