A New Tectonic Model Between the Madagascar Ridge and Del Cano Rise in the Indian Ocean

The southern Indian Ocean has several prominent aseismic ridges recognized as oceanic large igneous provinces (i.e., the Madagascar Ridge, Del Cano Rise, Crozet Plateau, and Conrad Rise) in off-axis areas of Southwest Ridge (SWIR). However, previously obtained magnetic survey lines are sparse not correctly aligned with seafloor spreading direction; thus, detailed history, including formation these ridges, remains an open question. We reconstructed tectonic history two segments between Discovery II Gallieni fracture zones SWIR using newly data (total vector field) open-source set. revealed that Rise once formed a single bathymetric high separated by at least Chron 30y, which is quite different from global age model. In addition, rises may have before 34y, assuming extinct ridge south Rise. been having Marion hotspot plume-induced excess volcanism around active SWIR, can explain locally isostatically compensated thicker-than-normal crust. linear anomalies observed across main part rises, suggesting magmatic activity controlled unlikely. Like other Ocean, possibly partly continental fragments rather than volcanism.