Abstract

PORTELA, Paulo J. Cesário et al. Age modelling of sedimentary sequences using a bayesian approach the Bensafrim estuary sedimentary infilling sequence as a case study. Finisterra [online]. 2019, n.112, pp.113-130. ISSN 0430-5027.  https://doi.org/10.18055/Finis16084.

The Bensafrim estuary, located in Southern Portugal (Algarve coast), was selected to assess the evolution of the fluvial-marine interaction along the Portuguese coast during the last 5000 years. Sedimentary sequences were collected in this estuary and radiocarbon dated, providing the necessary chronological framework to establish a reliable palaeo-environmental reconstruction. A Bayesian approach was employed in an attempt to overcome some difficulties related with the chronological data, which was performed using the OxCal calibration software, which allows the incorporation of stratigraphic information and an outlier analysis of the dataset. The analysis enabled the identification of outliers and the assessment of a reliable deposition model for the sedimentary sequence, establishing a robust chronological framework for the last 5000 years in this region of the Portuguese coast. Also, this model associated with sedimentological characterization points to the presence of high-energy events, including eventually the tsunami that followed the Lisbon earthquake of 1755.

Keywords : Radiocarbon; Bayesian statistics; Bensafrim estuary; sediments; Lisbon tsunami 1755.

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