Evaluating global paleoshoreline models for the Cretaceous and Cenozoic

Abstract

Paleoshoreline maps represent the distribution of land and sea through geological time. These compilations provide excellent proxies for evaluating the contributions non-tectonic vertical crustal motions, such as mantle convection-driven dynamic topography, to the flooding histories of continental platforms. Until now, such data have not been available as a globally coherent compilation. Here, we present and evaluate a set of Cretaceous and Cenozoic global shoreline data extracted from two independent published global paleogeographic atlases. We evaluate computed flooding extents derived from the global paleoshoreline models with paleo-environment interpretations from fossils and geological outcrops and compare flooding trends with published eustatic sea-level curves.Although the implied global flooding histories of the two models are similar in the Cenozoic, they differ more substantially in the Cretaceous. This increase in consistency between paleoshoreline maps with the fossil record from the Cretaceous to the Cenozoic likely reflects the increase in the fossil preservation potential in younger geological times. Comparisons between the two models and the Paleogeographic Atlas of Australia on a regional scale in Australia reveal a higher consistency with fossil data for one model over the others in the mid-Cretaceous and suggest that a review of the interpretation of the Late Cretaceous–Cenozoic paleogeography may be necessary. The paleoshoreline maps and associated paleobiology data constraining marine vs terrestrial environments are provided freely as reconstructable GPlates-compatible digital files and form a basis for evaluating the output of geodynamic models predicting regional dynamic surface topography.