A tracer-based algorithm for automatic generation of seafloor age grids from plate tectonic reconstructions. (July 2020)

• Record Type: Journal Article
• Authors: Karlsen, Krister S.; Domeier, Mathew; Gaina, Carmen; Conrad, Clinton P.
• Is Part Of: Computers & geosciences. Volume 140(2020)
• Publication Date: 2020-07
• Subjects: Paleozoic -- Seafloor age grids -- Plate tectonic reconstructions -- Sea level change -- Oceanic lithosphere -- Reconstructed bathymetry; Environmental policy -- Periodicals; 550.5
• DOI: 10.1016/j.cageo.2020.104508
• Languages: English
• ISSNs: 0098-3004

Abstract

Abstract: The age of the ocean floor and its time-dependent age distribution control fundamental features of the Earth, such as bathymetry, sea level and mantle heat loss. Recently, the development of increasingly sophisticated reconstructions of past plate motions has provided models for plate kinematics and plate boundary evolution back in geological time. These models implicitly include the information necessary to determine the age of ocean floor that has since been lost to subduction. However, due to the lack of an automated and efficient method for generating global seafloor age grids, many tectonic models, most notably those extending back into the Paleozoic, are published without an accompanying set of age models for oceanic lithosphere. Here we present an automatic, tracer-based algorithm that generates seafloor age grids from global plate tectonic reconstructions with defined plate boundaries. Our method enables us to produce novel seafloor age models for the Paleozoic's lost ocean basins. Estimated changes in sea level based on bathymetry inferred from our new age grids show good agreement with sea level record estimations from proxies, providing a possible explanation for the peak in sea level during the assembly phase of Pangea. This demonstrates how our seafloor age models can be directly compared with observables from the geologic record that extend further back in time than the constraints from preserved seafloor. Thus, our new algorithm may also aid the further development of plate tectonic reconstructions by strengthening the links between geological observations and tectonic reconstructions of deeper time. Graphical abstract: Highlights: Open-source code to generate seafloor age grids from plate tectonic reconstructions. First published seafloor age grids of the Paleozoic's lost ocean basins. Paleozoic sea level change inferred from new paleo-oceanic lithosphere age models.