High-resolution kinematic study of the Late Mesozoic to Late Cenozoic seafloor spreading at the Central Mid-Atlantic Ridge.

The Central Atlantic oceanic crust documents the evolution of seafloor spreading along the Central Mid-Atlantic Ridge. Previous works have identified marine magnetic anomalies (i.e., isochrons) every ~7 Myr for the pre-Neogene time, thus, the existing Nubia-North America plate kinematic models suffer from rather crude temporal resolution. Here, we present preliminary results from a detailed plate kinematic investigation aiming to reconstruct the kinematics of seafloor spreading at ~1.5 Myr time intervals. Our model is constrained by ~11000 identifications of 40 magnetic reversals younger than C34y (83.6 Ma) and older than C6no (19.7 Ma). We also investigated the fracture zones using multibeam bathymetry and satellite-derived gravity data. These identifications are confined by the Fifteen-Twenty fracture zone in the south and the Azores triple junction in the north. We invert these identifications and fracture zone crossings to estimate a set of finite rotation poles and stage rotations. We confirm the validity of our plate kinematic solutions by comparing a set of synthetic flowline tracks to the location of fracture zone traces. Based on these new poles, we present a detailed kinematic analysis that sheds new light on the evolution of the Central Atlantic since the Late Mesozoic.