Investigations on the origin, evolution and geomorphological significance of the Las Chapas/Cabopino dunes as an Atlantic/Mediterranean hybrid coastal dune system in Marbella, Málaga

espanolEl sistema dunar Las Chapas / Cabopino se encuentra en la costa mediterranea de Andalucia. El desarrollo turistico de los ultimos 60 anos ha oscurecido el sistema de dunas posiblemente mas significativo del Mediterraneo occidental en terminos de tamano, complejidad geomorfologica e importancia sedimentologica. Una combinacion de suministro extensivo de sedimentos, espacio de alojamiento y energia eolica / oleaje durante los ultimos 18.000 anos ha dado lugar a un extenso campo de dunas cuya genesis y evolucion todavia no se conoce completamente. Entre los diversos tipos de dunas -identificados a traves de fotointerpretacion y validados con recientes trabajos de campo-, hay una variedad de campos parabolicos e imbricados, dunas transversales y de Nebkhas. Tambien se llevo a cabo una campana de georadar para examinar la estructura interna de las dunas que muestra en sus resultados preliminaries, lechos cruzados y otras caracteristicas deposicionales eolicas inequivocas (como slipfaces). El origen de este extenso campo de dunas, inusual en un entorno mediterraneo, debe vincularse a un aporte de sedimentos a gran escala que no solo esta relacionado con el suministro de sedimentos procedentes de cuencas fluviales (como con la mayoria de los sistemas de dunas mediterraneos) sino tambien a procesos de dinamica del nearshore (similar a las dunas del Atlantico Norte). EnglishThe Las Chapas/Cabopino dune system is located in the Mediterranean coast of Andalusia. The development of tourism over the last 60 years has helped obscure from view perhaps the most significant dune system in the western Mediterranean in terms of size, geomorphological complexity and sedimentological significance. A combination of extensive sediment supply, available (accommodation) space to position a dunefield, and suitable wind/wave energy over the last thousand of years has resulted in an extensive dune field whose genesis and evolution is not fully understood nor described adequately. The dune system was delineated through photo-interpretation using 1944 and 1956 aerial photography and validated by recent ground-truth surveys. Among the various dune types present, a variety of imbricated parabolic and parabolic dune plains, as well as transverse and Nebkhas dunes were identified. Preliminary ground penetrating radar was also conducted to examine the internal structure of the dunes to show distinct cross bedding and other unequivocal aeolian depositional features. Here we propose a conceptual evolutionary model for the origin of this large coastal dunefield which is unusually large for a Mediterranean setting. We purport that its existence may be linked to large scale sediment input that is not only connected to riverine sediment supply (as with most other Mediterranean dune systems) but also to nearshore dynamics (similar to North Atlantic dunes).