Last glacial maximum and late glacial aeolian sand activity, south-central Indiana, USA

Abstract The chronology of Late Pleistocene and Holocene aeolian sand activity in midcontinent North America provides important insight into paleoenvironmental change and associated surface processes. Near the limit of Marine Isotope Stage 2 glaciation of the Huron-Erie Lobe (Laurentide Ice Sheet) in south-central Indiana, aeolian sand deposits found along the eastern margin of outwash plains in the East Fork and West Fork White River valleys provide an opportunity to test the causal mechanisms for aeolian sand activity. Twenty-five optically stimulated luminescence ages on aeolian sand and four radiocarbon ages on gastropod shells document two phases of aeolian sand activity. The first phase, between 26 and 19 ka, records deflation from active outwash plains in the East Fork and West Fork White River valleys during and after the local glacial maximum. These ages overlap with the chronology of Huron-Erie Lobe advance into and out of the White River drainage basin based on a radiocarbon-dated slackwater succession. The second phase, between 16 and 12 ka, records reworking of older aeolian sand and outwash during a period of no-analog vegetation during the Bølling-Allerød/Younger Dryas and is in general agreement with the timing of dune activity from previous studies in the Great Lakes region.