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

裂谷边缘是人口密集的地区，地下蕴藏着主要的能源资源。然而，控制大陆边缘形成的地质过程还没有被很好地理解。拟议项目的目的是限制共轭边缘伸展和地壳减薄的时间和空间分布，以深入了解大陆边缘形成的地质过程。第勒尼安盆地是一个边缘有活动裂谷作用的封闭裂谷盆地，其中心部分具有保存完好、未变形的共轭边缘的优势。这使得它成为研究裂隙边缘形成过程的理想自然实验室。我们提议与西班牙和意大利的合作伙伴合作，在一个多学科项目中解决这些问题。新的数据将在2010年4月的两艘船作业期间获得。西班牙的R/V Sarmiento de Gumbera将收集多通道地震(MCS)数据，并操作气枪进行地震折射和广角工作。将部署用于折射工作的海底站，并从意大利R/V Urania号船上回收。几个地球物理断面将横穿第勒尼安盆地，采样在不同拉伸量下形成的共轭边缘。通过对比不同断面的地震反射和地震折射资料得到的地壳和上地幔结构，可以用空间(具有不同伸展因子的不同区域)换取时间(伸展演化)来揭示大陆边缘形成过程的演化。

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).