Rifting of continental margins and evolution of conjugated margins in the Tyrrhenian Sea caused by subduction-related slab roll back

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Rifted margins are areas of dense population and host major energy resources in the subsurface. However, the geological processes that control the formation of continental margins are yet not well understood. It is the aim of the proposed project to constrain the temporal and spatial distribution of stretching and crustal thinning of conjugate margins to gain insight into the geological processes underlying continental margin formation. The Tyrrhenian Basin is a confined rift basin with active rifting at its edges and it has the advantage of well preserved, un-deformed conjugate margins in its central part. This makes it an ideal natural laboratory to study the formative processes of rifted margins. We propose a collaborative project with partners from Spain and Italy to address these questions in a multi-disciplinary project. New data will be acquired during a two ship operation in April 2010. The Spanish R/V Sarmiento de Gamboa will collect multi-channel seismic (MCS) data and operate airguns for seismic refraction and wide-angle work. Ocean-bottom stations for the refraction work will be deployed and recovered from the Italian vessel R/V Urania. Several geophysical transects will cross the Tyrrhenian Basin, sampling conjugate margins that have been formed under different amount of stretching. The comparison of the crustal and upper mantle structure derived from seismic reflection and seismic refraction data along different transects will permit to unravel the evolution of the processes of continental margin formation by trading space (different areas with different stretching factors) for time (evolution of extension).