Mantle convection is a fundamental driving force for the tectonic activity of our planet. It is commonly perceived that mantle convection is difficult to constrain directly. Its processes, however, affect the surface of the Earth and leave an imprint in the geological record. One response to topographic changes driven by mantle convection is the development of unconformities in the geological record (i.e. the absence of a stratigraphic layer), due to non-deposition or erosion. Modern geological maps allow systematic mapping of such unconformable surfaces at the continental scale.
Here we report our recently published work on the extraction of conformable and unconformable contacts (continent-scale hiatus mapping) in geological series across America, Europe, Africa, and Australia, from the Upper Jurassic onward. We find significant differences in the spatial extend of hiatus patterns across and between continents at geological series, ten to a few tens of Million years (Myrs). This is smaller than the mantle transit time, which, as the timescale of convection, is about 100–200 Myrs, implying that different timescales for convection and topography in convective support must be an integral component of time-dependent geodynamic Earth models. For the Cenozoic sedimentary cover of Europe the maps show a large hiatal surface of the Paleocene. This surface precedes the arrival of the Iceland plume and the change in motion of the North Atlantic ridge in the early Eocene.
Our results call for intensified collaboration between geodynamicists and geologists to improve our understanding of interregional-scale geologic events.