Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

J.R. Reid


Seven lithostratigraphic units are recognized in the glacial sediment {till) of southeastern North Dakota. Five of these units are not formally named; eventually most of these units will be correlated with formations in surrounding regions. Two of these units, Gardar and Dahlen, are formations recognized in northeastern North Dakota {Hobbs, 1975). The seven lithostratigraphic units are differentiated and correlated using the percentage of the sand, silt, and clay fractions of the till and using the proportion of igneous and metamorphic rock fragments, limestone and dolomite fragments, and shale fragments in the very-coarse-sand fraction (1 to 2 mm) of the till. The proportions of sand and shale are the most important field criteria for identifying the units in this area and, along with stratigraphic position, are the primary criteria for distinguishing the units.

The lower three units, A, B, and Care recognized only in Ransom County, southern Barnes County, and in northern Sargent County. The Gardar Formation is recognized in LaMoure, Barnes, Ransom, and Sargent Counties and the Dahlen Formation and unit D are recognized throughout the study area with exception of Wells County. Unit E, the youngest lithostratigraphic unit in the area, is recognized only in Wells, Stutsman, and LaMoure Counties.

Where observed, the uppermost lithostratigraphic units cross three previously recognized end moraines in southeastern North Dakota: the Grace City, the Oakes, and the Luverne End Moraines. On the basis of the lithostratigraphy of the glacial sediment of southeastern North Dakota, these arcuate ridges may be overridden older terminal moraines or they may not even be terminal moraines and new criteria must be used for recognizing terminal moraines in this area.

Camara (938681 kB)

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