DEGLACIATION AND POST-GLACIAL CLIMATE CHANGE IN A REGIONAL NETWORK OF SITES, OHIO AND EASTERN INDIANA

Details regarding the timing of deglaciation and subsequent late Glacial climate change in the North American Midwest have remained vague, due to a paucity of paleoclimate data for this region. Current work on a network of ~30 relict basin sites seeks to rectify this gap. Most of these sites formed directly after deglaciation, between 16,500 – 15,000 ¹⁴C years BP. Radiocarbon dating of organic material from the base of site cores chronologically defines basin formation. Compiled in a probability curve, these basal dates show a strong regional pattern: c. 15,500 and 14,800 ¹⁴C years BP are peak times during which the majority of basins formed.

Post-glacial environmental change includes stratigraphic or biologic changes, as defined by proxy analyses, upsection of the basal date. Probability analysis of these dates show regional transitions at 13,500, 12,500, and 11,500 ¹⁴C years BP. While the specific lithologic or biologic characteristics of these environmental changes may vary between individual sites, the temporal pattern is still present on a regional scale.