1999/03/25 by Thomas V. Lowell, G. Larson, John Hughes +1 · 4 citations
Earth and Planetary Sciences · Social Sciences · #Geology and Paleoclimatology Research #Pleistocene-Era Hominins and Archaeology #Archaeology and ancient environmental studies
paper · doi:10.1139/e98-095
openalex publication_date 1999/03/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/11
Analysis of nine wood samples from the Lake Gribben forest bed near Lake Gribben, Michigan, yielded a combined age of 10 025 ± 100 14 C years BP, which confirms and refines prior age estimates for the bed. The stratigraphic position of these samples below a prograding ice-contact fan indicates the time that a glacial margin reached the southern edge of the Lake Superior basin. Geomorphic tracing and correlation of associated deposits indicate that a contemporaneous margin extended almost 1000 km from Duluth, Minnesota, across the Lake Superior basin to North Bay, Ontario. Along the southern shore of Lake Superior ice-margin expansion began during and ended at the close of the Younger Dryas. A surging glacier system would not produce a nearly linear moraine system across both a major basin (Lake Superior) and a major upland (Abitibi Upland). Therefore, we attribute this advance of the Laurentide Ice Sheet to climatic forcing of the Younger Dryas event.