Abstract
- Stratigraphic sequences from the west-central coast of Portugal, newly-dated by optically-stimulated luminescence, demonstrate geomorphic responses to climate and sea level change during Marine Isotope Stages 3 and 2. Three raised beach deposits dating to this period are preserved in various tectonic settings between Peniche and São Pedro de Muel, recording sea level high stands at around 62, 41, and 36 thousand years BP. The coastal sequences are buried by aeolian sands that extend up to 15 km inland. Luminescence ages imply that the sand sheet was emplaced by 27,000 BP, and thick alluvial fills in coastal-draining rivers suggest high rates of upland erosion around the same time. During the glacial maximum, the coastal deposits were subject to colluviation and the valley fill deposits were reworked by aeolian activity and trenched by base level lowering. These findings highlight the magnitude of geomorphic response to climatic instability during MIS3, and provide some paleoenvironmental context for the newly-discovered archaeological sites in the region.