MORPHOLOGY AND ARCHITECTURE OF A LATE PLEISTOCENE CLIFF-FRONT DUNE, MALLORCA, WESTERN MEDITERRANEAN

Cliff-front dunes are a common coastal feature, but this is the first time that the structures indicative of their formation are documented. A late Pleistocene cliff-front dune in southern Mallorca has been stu died. Owing to early lithification of the calcarenite, its morphology is well preserved. The dune occurs in front of a curved, near-vertical coastal cliff, but the bedform cannot be classified as a fixed echo d une. The dune grew with time and its brinkline gradually moved closer to the cliff front. In the final stage of evolution the top of the dun e reached a height of at least 23 m. The dune is composed of wind-ripp le strata. These strata are arranged in critical to supercritical clim bing-dune cross-stratification recording its growth stages. The angle of climb of the dune increases toward the cliff and reaches 50 degrees . The morphological features of cliff-front dunes result from both cli ff slope and whether the cliff front is curved or straight.