Rift to drift transitions at passive margins
New geophysical data sets, field studies and dynamic and numerical modeling are rapidly refining our concepts of rifting and continental breakup. In turn, these concepts prompt as many new questions as they do answers. This session aims to highlight recent advances and unresolved questions, and provide debate on key issues concerning sequence and process in rifting, continental breakup, and early drifting. Does rifting continue into breakup, or do different processes take over? What are the vertical motions associated with rifting and breakup? Are syn-rift and breakup magmatism necessarily related? Can ultra-slow extension be associated with magmatic breakup (SDRs)? What underlies SDRs at magmatic margins, and what is responsible for their dip? Does lateral magmatic flux play a role in subsidence history? How do SDR complexes transition into oceanic crust? What is the lithospheric structure of marginal offsets in rifted margins? What are the short- and long-term heat flow consequences of differing crustal types? How does underplating actually occur, and does it affect subsidence and heat flow history? These and other questions should provide the basis for a state of the art snapshot of passive margin formation, which in turn sets the stage for assessing petroleum systems.
James Pindell and Rod Graham