Unravelling the Quaternary river incision in the western Rhenish Massif: Cosmogenic nuclide dating (10Be & 26Al) of fluvial terraces in the lower Moselle valley (Germany)

了解隆升的莱茵地块更新世河流切口的年代学对揭示区域构造行为具有重要意义。然而，到目前为止，主要河流的切口历史还没有得到很好的约束。虽然以前的许多研究都涉及莱茵河和摩泽尔河谷阶地剖面的重建，但其中很少有研究提供可靠的年龄估计，特别是对更新世中期和早期阶地的年龄估计。这些中更新世和早更新世阶地虽然代表了山谷形态和构造演化的关键阶段，但却缺乏可靠的绝对年代测定。在这个项目的框架内，我们打算使用地球宇宙形成核素（10Be, 26Al）来确定特里尔和科布伦茨之间的摩泽尔河谷下游的上阶地飞行。两种不同的采样/测年方法，深度剖面技术和等时线方法，将应用于不同的阶地水平，以便深入了解控制摩泽尔河谷渐进堑壕的河流切口脉冲。此外，同一梯田群的不同残余物将在山谷的不同地方取样，以解释切口率的潜在空间变化。因此，本研究的最终目的是扩大所需的数据集，以深入了解河流切口响应构造强迫（即区域岩石隆升）和气候强迫（即更新世冰期/间冰期旋回）的时空机制特征。

Understanding the chronology of Pleistocene river incision in the uplifted Rhenish Massif is of particular importance to unravel the regional tectonic behavior. However, the incision history of major rivers is poorly constrained to date. While many of the previous studies dealt with the reconstruction of terrace profiles in the Rhine and Moselle valleys, very few of them provided reliable age estimates, in particular for middle and early Pleistocene terrace levels. These middle and early Pleistocene terraces, though representing key levels in the morpho- and tectogenetic evolution of the valleys, suffer from a lack of reliable absolute dating. In the framework of this project, we intend to use terrestrial cosmogenic nuclides (10Be, 26Al) to date the upper terrace flight of the lower Moselle valley between Trier and Koblenz. Two distinct sampling/dating approaches, the depth profile technique and the isochron method, will be applied on different terrace levels in order to gain insight into the river incision pulses that governed the progressive entrenchment of the Moselle valley. Moreover, different remnants pertaining to the same terrace group will be sampled at distinct places along this reach of the valley to account for potential spatial variations of incision rates. Thus, the final aim of this research is to enlarge the dataset required to gain insights into the spatio-temporal characteristics of the mechanisms by which river incision responded to combined tectonic forcing (i.e. regional rock uplift) and climatic forcing (i.e. Pleistocene glacial/interglacial cycles).