Slab factory - ocean formation and subduction in the Western Alps

板坯工厂 - 西阿尔卑斯山的海洋形成和俯冲

• 批准号: 365184787
• 负责人: Professor Dr. Nikolaus Froitzheim
• 金额: --
• 依托单位: Arbeitsgruppe Strukturgeologie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/365184787?language=en
• 关键词: Slab; factory; ocean; formation; subduction

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).

阿尔卑斯山的深部结构已被岩石圈俯冲板片所改变，将在AlpArray的框架内通过地震方法对其进行成像。 在俯冲过程中，大洋地壳（蛇绿岩）的薄片从大洋板块上被剪切下来，成为暴露在地球表面的冲断岩席碰撞堆叠的一部分。它们携带着有关海洋形成、俯冲和碰撞历史的重要信息。该项目将结合使用结构地质学、变辉长岩的U-Pb锆石年代测定（以确定海洋扩张的年代）以及榴辉岩和蓝片岩的Lu-Hf石榴石年代测定（以确定俯冲的年代）来研究西阿尔卑斯山弧中的蛇绿岩。利用这些新数据和大量现有数据，将重建洋盆张开和俯冲的运动学，并预测俯冲板片的性质，以支持对AlpArray记录的岩石圈结构的解释，并作为构造演化模型（SPP活动场F，4-D建模）的输入。这些结果对于了解西阿尔卑斯山南端以及向亚平宁山脉和利古里亚海的过渡（AF-B（LOBSTER）的主题）特别重要。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化。该项目是活动领域E（地质活动）的一部分，涉及研究主题1（岩石圈重组）和3（地壳和地幔变形）。