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

了解莱茵隆升地块更新世河口的年代学对于揭示区域构造行为具有特别重要的意义。然而，到目前为止，主要河流的切割历史很少受到限制。虽然以前的许多研究涉及重建莱茵河和莫泽尔山谷的阶地剖面，但很少有研究提供可靠的年龄估计，特别是中更新世和早更新世的阶地水平。这些中更新世和早更新世的阶地，虽然代表了山谷形态和构造演化的关键水平，但缺乏可靠的绝对测年。在这个项目的框架内，我们打算使用陆地宇宙成因核素(10Be，26Al)来确定特里尔和科布伦茨之间的下莫泽尔山谷的上阶地飞行的日期。将在不同的阶地上应用两种不同的采样/测年方法，即深度剖面法和等时线法，以深入了解支配莫泽尔河谷逐渐挖坑的河流切割脉冲。此外，属于同一梯田组的不同残留物将在山谷这段不同的地方进行采样，以考虑切割率的潜在空间差异。因此，这项研究的最终目的是扩大所需的数据集，以深入了解河流切割对构造强迫(即区域岩石抬升)和气候强迫(即更新世冰川/间冰期旋回)共同作用的机制的时空特征。

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).