Sedimentary evolution of lagoons along the Namibian coast reveals fluctuation in Holocene biogeographic faunal provinces, upwelling intensity and sea level

Within the wave-dominated and high-energy depositional environment of hyper-arid Namibian coast, lagoons related saltpans represent one few regional settings in which sediments originating from both marine terrestrial sources can accumulate under sheltered conditions. This allows for an approximately continuous record mid to late Holocene coastal evolution. For this paleoenvironmental reconstruction, 26 sediment cores six (paleo-)lagoons were taken investigated along a 430 km-long latitudinal gradient. Based on 56 age determinations shell material, initial formation studied be dated back 6.0–5.3 cal kyr BP. The present different types lithoclastic assigned five sedimentary facies ranging sand spit rich material eolian dune sands evaporites. From these cores, 221 samples macrobenthic faunal have been collected determined possess 46 shallow species. Biogeographic analyses resulted identification 10 (sub-)tropical warm water species that are not part benthic fauna upwelling system. Age revealed four phases biogeographic range expansion/shift into study area, at 5.3 BP, 2.8 1.2–0.9 0.36–0.12 BP northern tropical Angola Current as well southern subtropical Agulhas Current. combination datasets with published sea-level fluctuations intensities presents apparent correlation between processes presumably additional linkage ENSO Benguela Niño variability.