GEOMORPHIC ANALYSIS OF REMNANT LAKESHORE FEATURES FROM DIGITAL ELEVATION MODELS OF THE EASTERN UPPER PENINSULA, MICHIGAN

The study area, the eastern part of the Upper Peninsula of Michigan was glaciated, until the final ice retreat that occurred 11.7ka causing the formation of pro-glacial lakes. Two of the lakes that were once present in the study area include Lake Algonquin (11ka) and Lake Nipissing (4.5ka). Lake Algonquin elevations were between 250-270m amsl and Lake Nipissing were 185-195m amsl, current day Lakes Huron and Michigan are at ~176m amsl. The Niagara Escarpment also outcrops in the study area. There are several littoral caves that are present within the Niagara Escarpment that were formed by the waves of Lake Algonquin.

Hillshade maps were made in ArcGIS and allowed for the search of features associated with near costal environments, such as strand plains and sand dunes. Coastal features at the eastern end of the Upper Peninsula appear to bin into different elevation groups: 250-265m amsl and 180-200m amsl; which correlate with the proglacial lake shorelines known in the region. These groupings of elevations clearly indicate that there would have been islands present during the existence of both lakes, Algonquin and Nipissing. This work may help to understand the isostatic rebound differential across the peninsula and explain the geomorphic features encountered in the field. Furthermore, these efforts will allow for a revision of the surficial geologic map of the area.