Abstract

It is now well-established that mantle convection and mantle processes influence Earth’s surface. However, it becomes important to carefully consider the timing and mechanisms that might drive these processes. For Southeast Asia, a significant Cretaceous-Eocene regional unconformity had been interpreted as a long hiatus in subduction along the southern Sundaland margin. I present work, namely forward geodynamic models of dynamic topography, that reconcile these surface observations with a shorter (~10-15 Myr) hiatus in subduction, which better explains the geological and geodynamic history of this region. In the case of the Cretaceous-age Eromanga Sea in Australia, new landscape evolution models suggest that dynamic topography plays a secondary role to lithospheric flexure and eustatic sea level. These examples highlight the need for numerical modelling approaches, and robust geological constraints, that allow us to test scenarios and evaluate the time-evolving dominance of key mechanisms controlling the evolution of Earth’s surface, which allows us to isolate the relative contributions of mantle flow, tectonics, and climate.