Identifying Main Lithospheric Structures in the Eastern Alpine Domain by Joint Inversion of Receiver Function and Surface Wave Measurements for Seismic Anisotropy

接收函数与地震各向异性面波测量联合反演识别东部高山域主要岩石圈结构

• 批准号: 442515292
• 负责人: Professor Dr. Mark R. Handy
• 金额: --
• 依托单位: Fachrichtung Geophysik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/442515292?language=en
• 关键词: Identifying; Main; Lithospheric; Structures; Eastern

Mountain building in the Alps started in the Neogene when crustal units derived from Eurasia, inter-vening oceanic basins and microcontinents got strongly deformed and folded by the approaching Adriatic intender. The eastern Alps are ideally suited to study the full complexity of mountain building including crustal delamination and deformation, nappe stacking and lateral escape. The underlying processes and in particular the driving forces remain enigmatic, however, because the crustal and deep lithospheric structure in the eastern Alpine domain are still poorly resolved. A pre-requisite for the understanding of mountain building processes since the Neogene in the eastern Alps is the identification of the shape of the intender and of the decoupling horizon for the lateral escape north of the suture as well as the clarification of the deep lithospheric structure. It re-mains an open question if Adria or Eurasia are the upper plate or if mountain building is the result of bivergent subduction. Also, properties of the mantle lithosphere need to be resolved as they are key for the quantification of tectonic forces causing collision and mountain building. AlpArray – the densest regional seismic array ever deployed contemporaneously - provides a unique opportunity to study the deep lithospheric structure of the orogen in detail. The complete data set for the eastern Alps will be available in 2021. Building on surface-wave and receiver-function measure-ments carried out in separate projects in the first phase of the SPP, we will perform a joint inver-sion of the data that will result in a high-resolution, shear-wave velocity model of the lithosphere to resolve both the absolute shear-wave velocity and major crust and mantle discontinuities. We will extend stochastic inversion schemes to obtain isotropic and anisotropic models and their uncertain-ties. The resulting high-resolution model will yield a seismic model for the eastern Alpine litho-sphere. Relating it to the geological record at the surface, the tectonic affinity of the main deep structures will be identified. Based on seismological observations, we will develop together with co-operation partners focusing on the research theme “Reorganizations of the lithosphere during moun-tain building” a 4D comprehensive model of the tectonic evolution of the lithosphere in the eastern Alps since the beginning of the Neogene. It will provide the basis for numerical geodynamic modelling of mountain building.

阿尔卑斯山脉的造山运动始于新近纪，当时来自欧亚大陆、其间的海洋盆地和微大陆的地壳单元因亚得里亚海的逼近而变形和折叠。东部阿尔卑斯山非常适合研究包括地壳分层在内的造山运动的全部复杂性。然而，由于东部的地壳和深层岩石圈结构，潜在的过程，特别是驱动力仍然是个谜。阿尔卑斯山东部地区自新近纪以来的造山过程的了解仍然很薄弱，先决条件是识别缝合线以北横向逃逸的意图形状和解耦地平线。深部岩石圈结构的澄清仍然是一个悬而未决的问题，亚德里亚或欧亚大陆是否是上板块，或者造山是否是双向俯冲的结果。此外，地幔岩石圈的性质也需要研究。由于它们是量化导致碰撞和造山的构造力的关键，AlpArray（迄今为止部署的最密集的区域地震阵列）为详细研究造山带深层岩石圈结构提供了独特的机会。东阿尔卑斯山将于 2021 年推出。在 SPP 第一阶段的单独项目中进行的表面波和接收器函数测量的基础上，我们将进行联合反演这些数据将产生岩石圈的高分辨率剪切波速度模型，以解决绝对剪切波速度和主要地壳和地幔不连续性的问题，我们将扩展随机反演方案以获得各向同性和各向异性模型及其不确定性。由此产生的高分辨率模型将产生东部高山岩石圈的地震模型，将其与地表地质记录、主要深层构造的构造亲和力联系起来。基于地震观测，我们将与合作伙伴围绕“造山过程中岩石圈的重组”研究主题，共同开发东阿尔卑斯山岩石圈构造演化的4D综合模型。新近纪的研究将为造山运动的数值地球动力学模拟提供基础。