Multi-scale quantitative sedimentology of Upper Pleistocene coastal dunes from the Northern Bahamas and Western Australia.

This thesis investigates coastal dunes, specifically "chevrons," and their formation, highlighting their significance in understanding climate and sea level variations. Coastal dunes benefit ecosystems and populations but pose desertification risks if reactivated. The study originated from debates about the genesis of U-shaped "chevrons" in the Bahamas, dating to the Last Interglacial period, characterized by higher temperatures and sea levels.

A literature review revealed that "chevrons" are coastal parabolic dunes formed by wind, not superstorms or asteroid-induced tsunamis, as debated in the Bahamas, Madagascar, and Western Australia. Morphological, sedimentary, and grain size analyses confirmed their aeolian origin. Stratigraphic studies linked their formation to drier, windier climates and southward shifts in the Intertropical Convergence Zone during sea-level fluctuations.

Further investigations in Western Australia and continental regions connected dune activity to climate shifts caused by atmospheric circulation changes. During glacial periods, arid climates formed dunes, while interglacials stabilized them. This study emphasizes the relationship between dune activity, climate, and atmospheric circulation, offering insights for predicting future climate change and managing desertification risks.