Holocene cuspate forelands in the Strait of Magellan, southern Chile

The eastern inlet of the Strait of Magellan is characterised by the presenc e of two truncate cuspate forelands, typically high-energy accretionary mor phologies. Both forelands, Punta Catalina on the Fuegian side and Punta Dun geness on the Patagonian side, show similar features and accretionary trend s and could have been formed and developed at the same time during the late Holocene regressive phase. On the basis of air-photo interpretation, toget her with field survey, almost nine different accretionary phases of Punta C atalina spit can be recognised. Each phase is marked by an extensive beach- ridge system, and subsequent back-barrier mud-flat and marsh development. T he coastal retreat and erosion processes along the Atlantic side are respon sible for the shifting and morphological readjustment of the spit, which te nds to prograde towards the opposite direction, The strong eolian modelling over ancient beach-ridge systems, is marked by deflation furrows, hollows and nikes and subsequent construction of elongate parabolic dunes. Despite the lack of datings, a reconstruction of the system evolution was attempted , allowed by the evidence of a strong similarity with the Dungeness forelan d and considering the evolutionary framework of analogous accretionary coas tal forms in South America during late Holocene.