Geomorphology and Landscape Evolution of the Upper Mississippi Valley: Minneapolis, Minnesota to Guttenberg, Iowa

Abstract

A geomorphic evaluation of the Upper Mississippi Valley between Minneapolis, Minnesota and Guttenberg, Iowa indicates the area has undergone a complex sequence of Quaternary landscape evolution. The sequence of landscape evolution can be separated into four distinct stages. Stage one was characterized by valley entrenchment and development in response to the onset of continental glaciation. Valley aggradation and the development of a braided stream system dominated stage two, which spans the Late Wisconsin glacial maximum. Stage three was characterized by episodic downcutting and the development of an island braided stream system in response to glacial lake drainage through the valley. Net valley aggradation and development of the modem meandering stream system characterize the final stage of landscape evolution, from approximately 9,500 B.P. to the present.