Changes of North Atlantic plate motion in early Paleogene driven by Icelandic plume: Insights from kinematic and stratigraphic constraints

Mantle convection is a fundamental process that shapes the Earth's surface by providing the driving and resisting forces for horizontal motion of tectonic plates, as well as for inducing non-isostatic vertical motion commonly termed “dynamic topography”. Growing observational constraints of past plate motion and dynamic topography have led to better understanding of the history of surface expression induced by mantle flow. Often these two surface motion signals are studied separately. However, the existence of a thin, mechanically weak asthenosphere allows geodynamicists to link horizontal and vertical motion changes together via mantle flow properties in the context of pressure-driven Poiseuille-type flow. In this paper, we utilize publicly available geologic and geophysical datasets to study early Paleogene plate kinematics and spatiotemporal evolution of dynamic topography in the North Atlantic region. We find that the North America (NAM) and Greenland (GRN) plates experienced a rapid kinematic change around late Paleocene–early Eocene, coinciding with episodes of surface uplift inferred from stage-resolution stratigraphic information around the North Atlantic, Labrador Sea and Baffin Bay. We quantitatively tie these surface motion signals together to underlying asthenospheric flow processes by estimating torque variations on NAM and GRN. These are parameterized in terms of reconstructed kinematic changes as well as predicted Poiseuille-type flow induced by increasing Icelandic plume flux and speedup of Farallon slab. Our analysis indicates (1) that the torque-change associated with the Icelandic plume flux closely resembles the ones inferred from kinematic reconstructions, and (2) that the inclusion of slab effects does not modify significantly such a scenario. Our findings shed light on the role of asthenospheric channelized flow generated by the Icelandic plume in influencing the early Paleogene North Atlantic surface dynamics.