Inverse methods for modeling non-rigid plate kinematics: Application to mesozoic plate reconstructions of the Central Atlantic

Published plate reconstructions commonly show significant differences in initial plate configuration and syn-extensional opening directions. The variability of published models is primarily due to the difficulty associated with restoring crustal stretching history. Here we present an inverse non-rigid kinematic method that inverts plate motion and present day crustal thickness to approximate the history of bulk lateral strain and crustal thinning associated with lithospheric stretching. The kinematic link between plate motion and bulk crustal thickness that is used with this method is based on insights obtained from geodynamic models. We implement this approach in open source kinematic modeling software and apply it to test new Early Mesozoic plate kinematic models of the Central Atlantic. This application shows that the patterns of stretching inferred from the syn-rift basins of the Newark Supergroup can be explained if (1) syn-rift Euler pole flow lines were parallel to the Grand Banks transform margin and (2) initial formation of the East Coast Margin Igneous Province was coincident with the formation of the Central Atlantic Magmatic Province. These syn-rift to breakup models of the Central Atlantic lead to better constrained models of early seafloor spreading that show full spreading velocities in the ultraslow regime and within the transition from ultraslow to slow spreading regimes.