Geology of the Cuyuna Range

Abstract

Introduction Since the discovery of the Cuyuna district in central Minnesota one of the most perplexing problems has been the geological succession of the strata and their correlation with the known formations of the Lake Superior district. Undoubtedly the chief reason for the divergent opinions with respect to correlation lies in the fact that there are but a limited number of surface exposures in the entire region of the Cuyuna Range, and those present are at a considerable distance from the productive portion of the range. In fact, the Cuyuna region has very few of the surface features that are frequently associated with a Lake Superior iron range, such as conspicuous topographic ranges with characteristic trends and numerous rock exposures. The country is flat, with a maximum relief scarcely over 150 feet. It is covered with a heavy mantle of glacial drift, with numerous morainic hills, lakes, and swamps. The . . .