Late Holocene coastal dynamics, climate pulses and low terraces in the coast of the state of São Paulo, southeast, Brazil

Abstract

The lower Ribeira de Iguape stream – located in São Paulo, Brazilian southern coast, exhibits complex geomorphologic characteristics that resulted from multiple processes developed during the late Holocene. The present study proposes discussions about the possible relations between short-term climate events from the late Holocene (Climate Pulses) promoting the coastal dynamics and genesis of different levels of low fluvial-marine and marine terraces located in the study area, a subject rarely considered in other studies in humid tropical regions. The procedure of work included grain-size analyses and optically stimulated luminescence (OSL) dating of sediment samples collected from different depositional packages. Four depositional events resulted from transgressive and regressive events geochronologically related with climate pulses from the late Holocene were identified. The events can be summarized as follows: I) Marine Transgression (∼3.5–2.7 ka); II) Marine Regression (2.7–1.8 ka); III) Marine Transgression (1.8–0.65 ka); IV) Marine Regression (0.65–0.10 ka).