Compared structure and evolution of the conjugate Demerara and Guinea transform marginal plateaus

The Demerara and Guinea plateaus are conjugate Transform Marginal Plateaus (TMPs) formed at the junction of Jurassic Central Atlantic Ocean Cretaceous Equatorial Ocean. We compare their structure evolution through a combined industrial/academic seismic dataset tied by well data. show that these TMPs record complete history from to breakup seafloor spreading phases. Both first as volcanic margins displaying successive SDR wedges migrating towards newly forming domain. In this context, Guinea, conjugates Bahamas, seem have in relation plume activity southern end Our suggests initially represented two distinct extrusive centres separated crustal basement high. Later, during opening phase, both transform mode following discontinuity. Deformation is notably asymmetric phase: Aptian Albian folding, strike-slip, transtensive deformation complex vertical movements on side only minor Guinean side, except its divergent Sierra Leone termination. sealed regional upper erosion unconformity. Extensional reactivation occurs (probably general collapse?). To conclude, study provides new insights into nature origin key tectono-sedimentary archives they may contain understand polyphase conditions Gondwana. • describe TMPs. They end. then opening. Therefore, long-term Gondwana breakup.