Sea-level rise since 8.2 ka recorded in the sediments of the Potengi-Jundiai Estuary, NE Brasil

We present the first data set on the evolution and Holocene infilling of the Potengi River Estuary at the NE Brazilian Continental Margin near the city of Natal. The study is based on integrated sedimentological, geochemical and palaeontological information from 6 boreholes drilled in the area of estuarine mangroves, complemented by radiocarbon dating of the in situ remains of mangrove vegetation. Four samples taken close to the pre-inundation substratum set the baseline of reference points for the sea-level reconstruction. This palaeoenvironmental reconstruction, coupled with a C-14 age model, complements previous sea-level studies along the Rio Grande do Norte coast, which have been based primarily on beach-rocks and other on-shore exposed sedimentary materials. A rapid sea-level rise, at an averaged rate of approximately 6.1 mm/yr(-1), occurred between 8300 and 7000 cal. yr BP. Since then, the pace of relative sea-level rise slowed and non-eustatic factors, namely terrigenous sediment supply and coastal dynamics, became dominant in the evolution of the estuary. The post-transgression period witnessed the decline of mangroves, whose remnants were identified mostly in the initial 2 m of Holocene estuarine sediments. Accelerated sea-level rise, combined with geomorphological con, finement of the studied intertidal zone, was probably responsible for the demise of halophyte vegetation, which thrived again in the late Holocene. (C) 2015 Elsevier B.V. All rights reserved.