Improving global paleogeography since the late
Paleozoic using paleobiology
Wenchao Cao1, Sabin Zahirovic1, Nicolas Flament1,a, Simon Williams1, Jan Golonka2, and R. Dietmar Müller11EarthByte Group, School of Geosciences, The University of Sydney, NSW 2006, Australia 2Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Mickiewicza 30, 30-059 Kraków, Poland acurrent address: School of Earth and Environmental Sciences, University of Wollongong, Northfields Avenue, Wollongong, New South Wales 2522, Australia
Received: 16 Mar 2017 – Accepted for review: 14 Apr 2017 – Discussion started: 18 Apr 2017
Abstract. Paleogeographic reconstructions are important to understand Earth's tectonic evolution, past eustatic and regional sea level change, hydrocarbon genesis, and to constrain and interpret the dynamic topography predicted by time-dependent global mantle convection models. Several global paleogeographic maps have been compiled and published but they are generally presented as static maps with varying temporal resolution and fixed spatial resolution. Existing global paleogeographic maps are also tied to a particular plate motion model, making it difficult to link them to alternative digital plate tectonic reconstructions. To address this limitation, we developed a workflow to reverse-engineer global paleogeographic maps to their present-day coordinates and enable them to be linked to any tectonic reconstruction. Published paleogeographic compilations are also tied to fixed input datasets. We used fossil data from the Paleobiology Database to identify inconsistencies between fossils paleo-environments and published paleogeographic maps, and to improve the location of inferred terrestrial-marine boundaries by resolving these inconsistencies. As a result, the overall consistency ratio between the paleogeography and fossil collections was improved from 76.9 % to 96.1 %. We estimated the surface areas of global paleogeographic features (shallow marine environments, landmasses, mountains and ice sheets), and reconstructed the global continental flooding history since the late Paleozoic based on the amended paleogeographies. Finally, we discuss the relationships between emerged land area and total continental crust area through time, continental growth models, and strontium isotope (87Sr/86Sr) signatures in ocean water. Our study highlights the flexibility of digital paleogeographic models linked to state-of-the-art plate tectonic reconstructions in order to better understand the interplay of continental growth and eustasy, with wider implications for understanding Earth's paleotopography, ocean circulation, and the role of mantle convection in shaping long-wavelength topography.
Cao, W., Zahirovic, S., Flament, N., Williams, S., Golonka, J., and Müller, R. D.: Improving global paleogeography since the late
Paleozoic using paleobiology, Biogeosciences Discuss., doi:10.5194/bg-2017-94, in review, 2017.