Exhumation mechanisms of middle to lower crust in the Tertiary Eastern Alps (Tauern Window)

东阿尔卑斯地区第三纪的中下地壳岩石（深度达~ 30km）仅暴露在陶恩窗的变质穹丘内。以往的研究认为，该变质穹窿是中新世沿其东西边界的伸展拆顶而发掘出来的。然而，一些观测和最近的模拟模型表明，挖掘是由与逆压剪切带相关的大规模地壳褶皱导致的，从而导致隆升和侵蚀。伸展拆顶形成的片麻岩圆顶的几何形状与褶皱和侵蚀形成的片麻岩圆顶的几何形状相似，但冷却年龄和冷却速率的空间分布不同。因此，我们将通过结合构造-地质年代学调查来检验不同的挖掘模型。通过对陶恩窗西叶部分地点的白色云母和黑云母Rb/Sr冷却年龄的研究，结合邻近地点的年龄整理，可以构建详细的冷却年龄等高线图。此外，我们将沿着不同的路径测量冷却速率，以获得冷却速率的空间分布。这些数据对缩短和/或伸展的具体机制具有诊断意义，从而导致深部地壳岩石的发掘。最后，我们将从几个大型左旋剪切带和陶恩窗的大型垂直褶皱的轴向面确定同动白色云母的年代。这些年龄将使我们能够测试直立褶皱是否与左旋剪切带和陶伦圆顶的发掘同时发生。

Middle to lower crustal rocks (up to ~ 30 km depth) of Tertiary age in the Eastern Alps are only exposed within the metamorphic dome of the Tauern Window. Past investigations concluded that this metamorphic dome was exhumed by Miocene extensional unroofing along its western and eastern boundaries. However, several observations and recent analogue models suggest that exhumation resulted from large-scale crustal folding associated with transpressive shear zones, leading to uplift and erosion. While the geometry of gneiss domes formed by extensional unroofing may be similar to that of domes formed by folding and erosion, the spatial distribution of cooling ages and cooling rates is different. Therefore, we will test different exhumation models, by applying a combined structural - geochronological investigation. Rb/Sr cooling ages on white micas and biotites from selected sites of the western lobe of the Tauern Window, combined with compiled ages of adjacent localities will enable us to construct detailed contour maps of cooling ages. In addition, we will measure cooling rates along different traverses in order to obtain a spatial distribution of the rate of cooling. These data are diagnostic for the specific mechanism of shortening and/or extension, which resulted in exhumation of deep crustal rocks. Finally, we will date synkinematic white micas from several large-scale sinistral shear zones and from the axial planes of the large-scale upright-folds of the Tauern Window. These ages will allow us to test if the upright folds were coeval with sinistral shear zones and exhumation of the Tauern dome.