Palaeoclimatic significance of co-occurring wind- and water-induced sedimentary structures in the last-interglacial coastal deposits from Bermuda andthe Bahamas

The late Pleistocene stratigraphic record from the Bahamas and Bermuda arch ipelagoes includes peculiar V-shaped coastal ridges and wedges of seaward-d ipping planar beds showing fenestral porosity up to 40 m above present sea level. Judging from this porosity, these landforms were till now interprete d as resulting from the action of giant waves during a period of climatic i nstability at the end of the last interglacial period. The occurrence of wi despread mm-thick laminae of aeolian origin (subcritically climbing transla tent stratification) throughout these deposits does not agree with this hyp othesis. It rather suggests that the V-shaped ridges and seaward-dipping be ds represent fossil parabolic and climbing aeolian dunes, respectively. The occurrence of fenestrae high above the intertidal zone could be related to both wave splashing and rainfall action. Parabolic dunes are restricted to the NW Bahamas. They were probably formed during a time interval (ca. 500- 5000 yr), when regional climatic conditions were dryer than today, and char acterized by persistently blowing NE trade winds. (C) 2000 Elsevier Science B.V. All rights reserved.