Dynamic topography and the planform of mantle convection since the Jurassic inferred from global continental hiatus maps

The planform is a defining feature of mantle convection. It can be gleaned from the stratigraphic record by mapping the continent-scale distribution of hiatus and no hiatus surfaces serving as a proxy for high and low dynamic topography. We carry this out for all continents apart from Antarctica for eight geological series since the Upper Jurassic, showing that: (i) the planform as indicated by our maps contains wavelengths of the order of 1000 km, smaller than the convective scales implied by the geoid. (ii) The planform changes on timescales of geological series (10-20 Myrs), smaller than the mantle transit time. (iii) Flood basalt eruptions are frequently preceded by hiatus surfaces. (iv) Some hiatus surfaces are not linked to any known plume, potentially reflecting the lateral transport of material in the asthenosphere. Our results reveal the importance of mantle viscosity stratification in shaping the convective planform and the resulting dynamic topography. Geodynamic Earth models should aim to reproduce the global characteristics of our maps, as well as specific regional events identified in this work. Finally, we separate the effects of sea-level variation from regional changes in base level induced by dynamic topography by contrasting the stratigraphic evolution of different regions.