Collision, mantle convection and Tethyan closure in the Eastern Mediterranean

Abstract

The Tethys Seaway once linked the Atlantic and Indo-Pacific oceans. Its gradual shallowing and closure impacted global ocean circulation, faunal diversification and climatic changes. In this Review, we evaluate the tectonic causes and the topographic changes across the Eastern Mediterranean over the past 66 Ma and explore the consequences of Tethys Seaway closure. Mantle convection led to collisional tectonic processes, mountain building and crustal thickening along the Tethyan realm. The Ethiopian flood basalts mark the arrival of the Afar plume at ~30 Ma, followed by northward-trending volcanic activity indicating that plume material had moved to northwest Arabia by ~20 Ma. Plume-induced mantle flow generated kilometre-scale uplift across East Africa, at ~8° N at ~35 Ma, and along Arabia and led to the formation of the Gomphotherium land bridge at 30° N, ~20 Ma. Afro-Arabian uplift contributed to the development of modern-like Asian monsoons, and the land bridge between Africa and Asia enabled one of the greatest faunal interchanges of the Cenozoic. The gradual shoaling and final closure of the Tethys Seaway likely facilitated the transition towards a stronger overturning circulation in the North Atlantic, contributing to the Cenozoic cooling trend. Future research should incorporate more detailed spatial and temporal uplift models into paleogeography and paleoclimate models to better simulate consequences for ocean circulation, climate and biogeographic dispersals. Closure of the Tethys Seaway marked the last connection between the Atlantic and Indo-Pacific oceans. This Review explores how mantle convection and associated volcanic activity caused Tethys Seaway closure and discusses the implications for ocean circulation, faunal diversification and climate.