Estimating palaeobathymetry with quantified uncertainties: a workflow illustrated with South Atlantic data

Abstract

Abstract We present and illustrate a workflow to produce palaeobathymetric reconstructions, using examples from the South Atlantic Ocean. With a recent high-resolution plate kinematic model as the starting point, we calculate an idealized basement surface by applying plate-cooling theory to seafloor ages and integrating the results with depths along the extended continental margins. Then, we refine the depths of this basement surface to account for the effects of sedimentation, variations in crustal thickness and dynamic topography. Finally, the corrected idealized surface is cut along appropriate plate outlines for the desired time slice and reconstructed using appropriate Euler parameters. In order to assess the applicability of modelled results, we critically examine the limitations and uncertainties resulting from the datasets used and assumptions made. Palaeobathymetry modelled with our approach is likely to be least reliable over parts of large igneous provinces close to the times of their eruption, and most reliable within the oceanic interiors for Neogene time slices. The uncertainty range is not smaller than 500 m for any significant region at any time, and its mean over 95% of locations in all time slices is close to 1800 m.