The strike-fed sandy coast of Southern Brazil

The Holocene barrier along the southern Brazilian coast is most likely the most continuous barrier structure in the world. This coast is characterized by a Holocene barrier extending for 760 km, interrupted by only six discontinuities, which are associated with narrow lagoonal inlets and river mouths. This coast is marked by a huge availability of sand, a gently sloping continental shelf, and incident waves of moderate to high energy. Together, these factors constitute ideal conditions for the formation of coastal barriers. During periods of low sea-levels, the continental shelf in front of the La Plata estuary was fed by immature fluvial sands delivered by the Paraná River, which were transported to the southern Brazilian coast by a predominantly northward littoral drift. Based on forecasts of sea-level rise, it will take decades or centuries for change to occur in the progradation of the regressive barriers along the coastal embayments. During the last centuries and millennia (Middle to Late Holocene), the evolution of this coast has been controlled by the variations in wave energy along the coast.