Late Cretaceous Ridge Reorganization, Microplate Formation, and the Evolution of the Rio Grande Rise – Walvis Ridge Hot Spot Twins, South Atlantic Ocean

Rio Grande Rise (RGR) and Walvis Ridge (WR) are South Atlantic large igneous provinces (LIPs), formed on the American African plates, respectively, mainly by volcanism from a hot spot erupting at Mid-Atlantic (MAR) during Late Cretaceous. Both display morphologic complexities that imply their tectonic evolution is incompletely understood. We studied bathymetry, gravity, vertical gravity gradient maps derived satellite altimetry to trace faults providing indications of seafloor spreading directions changes. also examined magnetic anomalies for time constraint reflection seismic data structural information. Abyssal hill fabric anomaly indicate area between RGR WR was anomalous C34 (83.6 Ma) C30 (66.4 owing reorganization right-lateral transform MAR. This event began ∼92 Ma as shifted south form multiple, short-offset transforms, with extending through ending before C30. Anomalous spacing discordant fault microplate core Cretaceous Quiet Zone seafloor. As MAR jumped eastward, this captured plate now resides mostly in basin main plateau related ridge east (East Rise). The ringed massifs, implying link volcanism. results presented here these two LIPs had complex history belies simple models.