New observations and modeling allow us to investigate the underlying processes responsible for volcanic and non-volcanic rift and passive margin formation. Key questions to be resolved include 1) what controls the amount and distribution of magmatism during volcanic to non-volcanic rift and passive margin formation. 2) How does magmatism impact the tectonic evolution of these systems and what are the structural and rheological controls of magmatism and feedbacks on tectonic deformation. 3) How are structural style of passive margin formation and magmatism linked? 4) What are the consequences of magmatic versus a-magmatic systems for the associated sedimentary basins? 5) What is the depositional environment for formation of seaward dipping reflector sequences and which processes control anomalous vertical motions during basin evolution? We encourage abstracts that offer new insights into processes underlying volcanic and non volcanic rift-passive margin formation from rift to ridge, using constraints from observations and modeling.