Cliff-Front Dune Development During the Late Pleistocene at SaFortalesa (Mallorca, Western Mediterranean)

Abstract

[eng] This study presents the first detailed analysis of a Late Pleistocene cliff-front dune in north-ern Mallorca (Western Mediterranean). The research is based on sedimentological fieldworkconducted in a disused coastal quarry, where stratigraphic columns were recorded andfacies were described in detail. Grain size analysis was performed using image-based mea-surements from representative samples, and palaeowind conditions were reconstructedthrough the analysis of cross-bedding orientations and empirical wind transport equations.The dune, corresponding to Unit U4, exhibits three distinct evolutionary stages: initial, in-termediate, and final. During the initial stage, sediment mobilisation required wind speedsof approximately 10 m/s from the south-southwest (SSW). The intermediate stage wascharacterised by variable wind velocities between 5 and 8 m/s from the west-southwest(WSW). In the final stage, average wind speeds reached 7 m/s from the west (W), withintermittent peaks up to 10 m/s. These findings underscore the critical influence of windregime and topographic constraints on aeolian sedimentation processes. By reconstructingwind dynamics and analysing sedimentary architecture, this work provides key insightsinto the interplay between climatic drivers and geological context in the development ofcoastal aeolian systems.