NORTHERN MICHIGAN'S COMINGLED MUNISING AND GRAND MARAIS MORAINES AND THEIR RELATIONS WITH RELICT SHORELINES OF GLACIAL LAKE ALGONQUIN

Glacial Lake Algonquin (GLA) was an extensive proglacial lake sequence that occupied large parts of the Michigan, Huron, and Superior lake basins during waning phases of the Laurentide Ice Sheet (LIS). This greater great lake is important because it links the evolutionary and geomorphic histories of lakes and landforms across the Great Lakes region. Our work relies on multiple lines of evidence; including pioneer-era and contemporary geologic surveys and maps, ground penetrating radar, OSL dating, and the global positioning system; to reinterpret the physical landscape of Eastern Upper Michigan (EUM). In general, we attempt to clarify geomorphic relationships among GLA and the so-called Munising and Grand Marais moraines. Specifically, we report the positions of relict shoreline features, which extend our knowledge of the Main (highest) and Ardtrea (2nd highest) stages of the GLA sequence in EUM, and we've added those positions to the GLA Dataset. The ancient water planes appear to have flanked and cut shorelines along the upland feature in question. The surface of an extensive relict delta occurs ~3 meters below the Main paleolake surface and ~3 meters above the Ardtrea surface; such superposition, when combined with other evidences, suggests the Munising Delta formed in and during the Main phase of Glacial Lake Algonquin.