Slab factory - ocean formation and subduction in the Western Alps

阿尔卑斯山脉的深部构造被俯冲的岩石圈板块所改变，并将在AlpArray框架下用地震方法成像。在俯冲过程中，海洋地壳（蛇绿岩）从海洋板块上剪切下来，成为地球表面暴露的逆冲板碰撞堆的一部分。它们携带着关于海洋形成、俯冲和碰撞历史的重要信息。该项目将结合构造地质学、变质岩的U-Pb锆石定年（以确定海洋扩张的年龄）和榴辉岩和蓝片岩的Lu-Hf石榴石定年（以确定俯冲的年龄）来研究西阿尔卑斯弧区的蛇绿岩。利用这些新数据和大量已有数据，将重建洋盆张开和俯冲的运动学，并对俯冲板块的性质进行预测，以支持AlpArray记录的岩石圈结构解释，并作为构造演化模型的输入（SPP活动场F， 4-D建模）。这些结果对于了解西阿尔卑斯山的南端以及亚平宁和利古里亚海的过渡（这是AF-B （LOBSTER）的主题）尤为重要。与AF-B项目合作，我们将重建阿尔卑斯山-亚平宁山脉过渡的运动学演变。该项目是活动场E（地质活动）的一部分，研究主题1（岩石圈重组）和3（地壳和地幔变形）。

The deep structure of the Alps has been modified by subducted slabs of lithosphere which will be imaged by seismic methods in the framework of AlpArray. During subduction, slivers of oceanic crust (ophiolites) were sheared off from oceanic slabs and became part of the collisional stack of thrust sheets exposed at the Earth surface. These carry important information about the history of ocean formation, subduction, and collision. The project will study ophiolites in the arc of the Western Alps using a combination of structural geology, U-Pb zircon dating of metagabbros (to determine the age of oceanic spreading), and Lu-Hf garnet dating of eclogites and blueschists (to determine the age of subduction). Using these new data together with the large amount of already existing data, the kinematics of ocean basin opening and subduction will be reconstructed and predictions will be made for the nature of subducted slabs in order to support the interpretation of lithospheric structures recorded by AlpArray and serve as input for models of the tectonic evolution (Activity Field F of the SPP, 4-D MODELING). These results will be particularly important for understanding the southern end of the Western Alps and transition into the Apennines and Ligurian Sea, the subject of AF-B (LOBSTER). In collaboration with the AF-B projects, we will reconstruct the kinematic evolution of the Alps-Apennines transition.The project is part of Activity Field E (Geological activites) and deals with Research Themes 1 (Reorganizations of the lithosphere) and 3 (Deformation of the crust and mantle).