Depositional architecture of the Holocene barrier in São Francisco Island, Santa Catarina, Brazil

Abstract

The geophysical method GPR (Ground Penetrating Radar) together with subsurface sampling with a vibrocore allowed to characterize the sedimentary facies and depositional architecture of the Holocenic portion of the Ilha de São Francisco do Sul coastal plain, located in the northern region of Santa Catarina State. The study area was divided into two distinct blocks, north and south, according to the sedimentary architecture defined by radar stratigraphy. The collected data allowed the characterization of beach, eolic, lagoon and estuarine depositional environments in the radargram profiles. The north block has reflectors consistent with barrier progradation during the sea level fall of 2.5 m in the last 5,000 years. At south block the reflectors show clear influence of paleochannels systems and spits in the barrier development, where the progradation occurred under the influence of the Babitonga paleoestuary dynamics.