SEA LEVEL EVIDENCE FOR A SIGNIFICANT REDUCTION OF THE LAURENTIDE ICE SHEET IN MIS 3, GEORGIA BIGHT, USA

Recently, Dalton and co-authors (2019) proposed a hypothesis for a significant reduction of the central region of the Laurentide Ice Sheet (LIS) from ca. 52-40 ka, Marine Isotope Stage (MIS) 3. During this retreat the Hudson Bay area or at least its southern portion was deglaciated. Corroborative evidence for this hypothesized reduction exists in the form of lowered sea levels in the Georgia Bight of the U.S. continental shelf that have been dated to early MIS 3 using a variety of geochronological methods. These sea level ages support the idea of much reduced LIS in early MIS 3 in synchrony with the geologic and age data developed by Dalton et al from the Hudson Bay Lowlands of central Canada.The agreement between these data sets support the need for a careful reassessment of Late Pleistocene climate variability, ice retreat/advance and a coupled sea level response to both.