In this paper, we present new exhumation ages for the imbricated proximal molasse, i.e. Subalpine Molasse, of the northern Central Alps. Based on apatite $(\mathrm{U}-\mathrm{Th}-\mathrm{Sm})/\mathrm{He}$ thermochronometry, we constrain thrust-driven exhumation in the Subalpine Molasse between 12 and 4 Ma. This occurs synchronously to the main deformation in the adjacent Jura fold-and-thrust belt farther north and to the late stage of thrust-related exhumation of the basement massifs (i.e. external crystalline massifs) in the hinterland. Our results agree with other findings along the north Alpine foreland. While site-specific variations in the mechanical stratigraphy of the molasse deposits influence the pattern of thrusting at the local scale, we observe that late-Miocene thrusting is a long-wavelength feature occurring along the north Alpine foreland roughly between Lake Geneva and Salzburg. The extent of this thrusting signal as well as the timing suggests that late-Miocene thrusting in the north Alpine foreland coincides with the geometries and dynamics of the attached Central Alpine slab at depth. Interestingly, this implies that the slab geometry at depth does not coincide with the boundary between the Eastern and Central Alps as observed in the surface geology. Using this observation, we propose that thrusting in the Subalpine Molasse and consequently also the late stage of thrust-related exhumation of the external crystalline massifs, as well as the main deformation in the Jura fold-and-thrust belt are at least partly linked to changes in slab dynamics.

中文翻译：

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北部高山前陆中的长波中新世晚期逆冲：对后期造山过程的影响

在本文中，我们提出了北部中部阿尔卑斯山近交带糖蜜的新掘尸年龄，即Subalpine Molasse。基于磷灰石$（\mathrm{ü}--\mathrm{钍}--\mathrm{m}）/\mathrm{他}$在热计时法中，我们将推力驱动的发掘限制在12至4 Ma之间的亚高山莫拉斯山脉。这与更北部的相邻侏罗褶皱冲断带的主要变形以及腹地基底质块（即外部晶体质块）的与推力有关的发掘晚期相同步。我们的研究结果与北部高山前陆的其他发现一致。尽管糖蜜矿床机械地层中的特定位置变化会影响局部尺度上的逆冲模式，但我们观察到，中新世晚期逆冲是一个长波波特征，大约发生在日内瓦湖和萨尔茨堡之间的北部高山前陆。该推力信号的范围和时机表明，在北部高山前陆中新世晚期逆冲与深处附接的中央高山板的几何形状和动力学一致。有趣的是，这意味着深部的平板几何形状与表面地质学中观察到的东阿尔卑斯山和中阿尔卑斯山之间的边界不一致。利用这一观察结果，我们认为，亚高山莫拉斯山的逆冲作用，以及因此而导致的与外部结晶质块的逆冲有关的发掘晚期，以及侏罗褶皱-冲断带的主要变形，至少与部分原因有关。平板动力学的变化。这表明，在地表地质中观察到的板坯几何形状与东部和中部阿尔卑斯山之间的边界不一致。利用这一观察结果，我们认为，亚高山莫拉斯山的逆冲作用，以及因此而导致的与外部结晶质块的逆冲有关的发掘晚期，以及侏罗褶皱-冲断带的主要变形，至少与部分原因有关。平板动力学的变化。这表明，在地表地质中观察到的板坯几何形状与东部和中部阿尔卑斯山之间的边界不一致。利用这一观察结果，我们认为，亚高山莫拉斯山的逆冲作用，以及因此而导致的与外部结晶质块的逆冲有关的发掘晚期，以及侏罗褶皱-冲断带的主要变形，至少与部分原因有关。平板动力学的变化。