High- and ultrahigh-pressure rock exhumation and tectonic structure of the southeastern Austroalpine crust

奥阿尔卑斯超单元是东阿尔卑斯的一堆异质逆冲板，在古近纪的奔宁洋向南俯冲和随后与欧洲的碰撞过程中形成了上板块。早些时候，在100 - 90 Ma，澳阿尔卑斯山脉的部分地区受到与俯冲有关的变质作用的影响，直至超高压（例如含金刚石片麻岩）。这一变质作用影响了东南倾俯冲带的薄大陆地壳。这些岩石（~90 ~ 80 Ma）的发掘尚未在运动学和力学方面得到理解，但对东阿尔卑斯山的构造演化、地壳和岩石圈几何以及它们与喀尔巴阡山脉、迪纳里德山脉和潘诺尼亚盆地的关系具有至关重要的意义。我们将对澳高山俯冲最深处的Saualpe-Koralpe-Pohorje杂岩（SKPC）进行挖掘研究，结合露头尺度的结构和应变分析，以及利用电子背散射衍射（EBSD）和飞行时间中子衍射进行微观结构和织构分析。因此，我们将研究在挖掘过程中积累的变形路径和应变的几何形状和分布，并验证SKPC是通过局部非圆柱形流动从俯冲带挤压出来的假设。我们将重建SKPC的几何形状，并逐步对其发掘进行逆向变形。我们将把我们的结果整合到东阿尔卑斯山的三维几何模型中。基于这些结果，我们将与SPP内其他研究SKPC变质演化和东阿尔卑斯深部岩石圈结构的项目密切合作，解释阿尔卑斯东部的深部地壳和岩石圈结构以及向喀尔巴阡山脉和迪纳里德山脉过渡的过程。

The Austroalpine Superunit is a pile of allochthonous thrust sheets in the Eastern Alps, forming the upper plate during Paleogene southward subduction of the Penninic ocean and the following collision with Europe. Earlier, at 100 to 90 Ma, parts of the Austroalpine were affected by subduction-related metamorphism up to ultrahigh pressures (e.g., diamond-bearing gneisses). This metamorphism affected thinned continental crust in a southeast-dipping subduction zone. The exhumation of these rocks (~90 to 80 Ma) is not yet understood in terms of kinematics and mechanics but of crucial importance for the tectonic evolution of the Eastern Alps, their crustal and lithospheric geometry, and their relationships with the Carpathians, Dinarides, and Pannonian Basin.We will study exhumation of the Saualpe-Koralpe-Pohorje Complex (SKPC), the most deeply subducted part of the Austroalpine, combining outcrop-scale structural and strain analysis, as well as microstructural and texture analysis using electron-backscatter diffraction (EBSD) and time-of-flight neutron diffraction. Thereby we will investigate the deformation path and the geometry and distribution of strain accumulated during exhumation and test the hypothesis that the SKPC was extruded from the subduction zone by localized, non-cylindrical flow. We will reconstruct the geometry of the SKPC and stepwise retrodeform its exhumation. We will incorporate our results into a 3D geometric model of the Eastern Alps. Based on these results we will interpret the deep crustal and lithospheric structure in the Eastern part of the Alps and the transition into the Carpathians and Dinarides, in close collaboration with other projects within the SPP that deal with the metamorphic evolution of the SKPC and the deep lithospheric structure of the Eastern Alps.