HOLOCENE LAKE-LEVEL CHANGES AND HUMAN HISTORY ALONG LAKES MICHIGAN AND LAKE SUPERIOR

In the Great Lakes, the relationship between shoreline environments and human activity has long been the focus of geologists, geographers, and archaeologists. Lake-level changes during the Holocene presented a dynamic landscape for prehistoric people living in the basins of northern Lake Michigan and the south shore of Lake Superior. Changing lake-levels meant alteration in coastal configurations and drastic changes in shoreline ecology both near shore and inland. Archaeologists indicate that people began developing adaptations to coastal environments in the Great Lakes area during the Middle Holocene. These first coastally-adapted people, who were from the Archaic period (8500-2000 BP), represent the start of the Inland Shore Fishery, a regional subsistence pattern that focused on the harvesting of fish from the Great Lakes. This adaptation is recognized in the archaeological record by the presence of specialized tools for fishing such as spears, hooks, gaffs, and net weights, as well as preserved fish remains. Based on interpretations of topographic maps and aerial imagery, detailed reconstructions of past Holocene shoreline environments allow a test of major archaeological ideas about human settlement in the region. During the Late Archaic period (5000-2000 BP), people settled along the Nipissing shoreline, which is preserved well above modern lake-levels. This shoreline formed a pattern of large embayments within major river valleys, older glacial meltwater channels, and low coastal areas. Large bay barriers and spits, with associated lagoon settings, formed in these embayments, and provided a focal point for Late Archaic settlement. Archaeological site settings reveal a strong emphasis on the use of quite water environments such as shallow bays, river mouths and lagoons. Post-Nipissing, depositional coastal environments often consist of extensive belts of beach ridges, with limited large prehistoric settlements associated with them.