Eurasian paleogeographic reconstructions for Cenozoic climatic and biotic evolution (Invited)
Résumé
The formation of mountain belts from the Tibetan plateau to the Alps associated with the closure of the Tethys is thought to be a major driver of Cenozoic climate and biotic evolutions. However, various competing geodynamic models imply very different mountain growth histories involving debated tectonic mechanisms. Furthermore, a growing dataset of environmental proxies is used to constrain surface uplift but the reliability of these proxies and the age of their sedimentary records are strongly debated. As a result, there is a crucial lack of reliable boundary conditions required to validate modeling of climate, landscape and biotic evolution. To fill this fundamental gap we review here diverging tectonic models and data to propose a set of global paleogeographies focusing on Eurasia. The construction of the paleogeographic maps was performed with Terra Antiqua a new dedicated QGIS plugin with user-friendly set of paleogeographic tools (http://paleoenvironment.eu/terra-antiqua/). It integrates into a revised plate tectonic circuit, paleoshorelines and paleo-elevation/bathymetry estimated from a global database of quantitative and qualitative surface proxies from an extensive literature reviews focused on key orogenic areas. The maps are available through an interactive website that enables to plot various proxy databases and plot user data rotated into past tectonic positions (https://map.paleoenvironment.eu/). We explore various landscape distributions with a focus on how the Tibetan Plateau, the neo-Tethys closure and the Paratethys epicontinental sea retreat may have contributed to Cenozoic atmospheric CO2 drawdown, the evolution of Asian monsoons and aridification or biotic interchange associated with the Grande Coupure.