Mass anomalies due to subducted slabs and simulations of plate motion since 200 My

cited By 11In this paper we present a dynamic model where lithospheric plates are driven by the density heterogeneities of the upper mantle. We suppose that these heterogeneities are only related to the presence of subducted slabs. Paleogeographic reconstructions are used to infer the location of paleo-slabs at different ages of plate tectonic history. We choose to focus our simulations on three particular stages following the break-up of Pangea (180 Ma), following the Cretaceous reorganization (100 Ma), and following the Eocene reorganization (40 Ma) as well as on the present-day tectonics. We obtain a very good fit to the motions given by paleogeographic reconstitutions. The simulations clearly show that the forces issued from the gravity flow of subducted slabs are able to drive the plates in the right direction and that the major plate reorganizations are determined by the evolution of subduction zone geometry. However, the success of these models for predicting the stages of steady plate motion should not hide the fact that the real mechanism that abruptly reorganizes plate motions occurs on a time-scale that does not pertain to fluid dynamics and remains to be elucidated. © 1995