Sea-level and climate events during the past 500'000 years: the record from fossil reefs and coastal deposits from the North Eleuthera and Mayaguana Islands, Bahamas (Fig.1)
supervisors: Pascal kindler
This research is suported by the Swiss National Science Foundation (grant n°200020-113356)
Summary: Fossil reefs and coastal deposits contain direct information on sea-level and climate fluctuations during the late Quaternary that supplement data derived from the study of ice cores and deep-sea sediments. Such knowledge is critical to decipher the mechanisms of sea-level and climate variations, and better constrain future global changes. Fossils reefs are precise indicators of former sea stands and can further be accurately dated with the U-series method. The sedimentological and petrographic characteristics of ancient coastal deposits register high-frequency sea-level and water-table changes, as well as climatic conditions during early diagenesis. The study of these two types of fossil deposits is thus highly complementary.
Coastal deposits (Fig.2) and fossil reefs (Fig.3) have been already studied in details in Bermuda , Barbados , Florida and the northern Bahamas . The framework of late Quaternary sea-level and climate changes in these areas is thus well established, although many uncertainties still remain. By contrast, the southeastern Bahamas have not been much studied in this respect, possibly because of their relative inaccessibility.
We therefore plan to bridge this gap by undertaking detailed stratigraphic, sedimentological and geochemical analyses of the coastal sediments and reefal terraces. We plan to focus on three main controversial topics: 1/ climate and sea-level during MIS 11; 2/ climate and sea-level during MIS 7 and 3/ high-frequency climate and sea-level changes during MIS 5e.