Date of Award
Master of Science (MS)
Southern Logan County, North Dakota, was glaciated at least three different times during the Pleistocene epoch. Scattered patches of highly weathered iron-cemented drift found in the area of eroded Cretaceous bedrock in southwest-era Logan County are very possibly pre-Wisconsinan in age. Two younger drift sheets of Wisconsinan age cover the remaining portion of the county. One of these drifts, the Napoleon drift, is probably early Wisconsinan, and the other, the Burnstad-Streeter drift, is likely late Wisconsinan in age.
A great diversity in types of glacial topography and individual features is found in southern Logan County. Excellent examples of end moraine, recessional moraines, ground moraine, outwash plains, meltwater channels, and ice-contact features were mapped. Great areas of “dead ice” or stagnation moraine are found in the central and eastern parts of the area.
Evidence in the form of large perched lake plains, outwash plains, and collapsed outwash plains, strongly suggests that great areas of glacial ice stagnated and ablated in place. There is evidence that stagnant masses of Burnstad ice still existed when the Streeter advance occurred; therefore, the Streeter drift deposits are thought to be essentially the same age as those of the Burnstad advance.
Due to the lack of direct tracing of moraines from better known areas, and the paucity of radiocarbon dates from this part of North Dakota, correlation with standard sections can be tentative at this time. Because of this situation, individual morphostratigraphic units were mapped where possible. Radiocarbon datings from this area are now in process, and may be valuable for correlation purposes when they become available.
Bonneville, John W., "The surficial geology of southern Logan County, North Dakota" (1961). Theses and Dissertations. 32.