Quantifying river incision and uplift in the Rhenish Massif by dating of fluvial terraces in the Rhine Valley using the 10Be–26Al burial dating method

莱茵高地是一个拥有保存完好的河流阶地序列的地区的突出例子。这些阶地是由莱茵河及其支流切入古生代基岩而形成的。狭窄陡峭的莱茵河河谷上最年轻的阶地--所谓的年轻主阶地--是一个重要的地貌标志，根据古地磁数据，推测其年龄为700-800 ka。利用这一年龄和莱茵河上年轻主阶地的高度，建立了莱茵地块河流切割和抬升的模型，该模型预测了700-800 ka时切割和抬升速率的突然增加。相比之下，另一种模型，这是基于大量的主要阶地的几百个钻孔和相关的整个阶地序列的莱茵河与古气候记录的识别，表明一个较老的年龄约。1.3年轻主露台的马。这一模式意味着莱茵地块的隆起和切割速率较慢且几乎恒定。为了更好地约束隆起和切割的历史，并决定哪个模型是正确的，绝对年龄测定的主要阶地的莱茵河是必需的。然而，这种年龄限制仍然缺失。为了量化历史的河流切割和隆起的莱茵地块，我们将日期最重要的主要阶地在高原河谷的莱茵河应用10 Be-26铝埋藏测年。这种创新的，仍然很少使用的方法可以测年河流阶地沉积物的年龄范围为0.4至5 Ma，即使阶地缺乏一个保存完好的表面，由于侵蚀，沉积的年轻覆盖层沉积物，和/或人为影响。正如我们的初步调查所证实的，莱茵河的阶地沉积物非常适合这种年龄测定。计划中的项目将在七个精心挑选的地点为莱茵河沿着的主要梯田提供第一个绝对的时间限制。有了这些年龄限制，将有可能重建的切割历史的莱茵河和构造隆起历史的莱茵地块在前所未有的细节，并与隆起的地球动力学原因。特别是，澄清年轻主阶地的年龄具有深远的影响，因为过去的几项研究都是基于700-800 ka年龄的假设。因此，该项目的结果将不仅是相关的莱茵地块的切割和隆升的历史重建，但也为景观演化，质量平衡，新构造学和时间依赖的隆升模型的研究。

The Rhenish Massif is a prominent example for a region with well preserved sequences of river terraces. These terraces formed by the incision of the Rhine and its tributaries into the Paleozoic bedrock. The youngest terrace above the narrow and steep Rhine valley – the so-called Younger Main Terrace – constitutes an important geomorphological marker, for which an age of 700-800 ka is assumed based on paleomagnetic data. Using this age and the height of the Younger Main Terrace above the Rhine, a model for river incision and uplift of the Rhenish Massif was developed, which predicts an abrupt increase in the rate of incision and uplift at 700-800 ka. In contrast, an alternative model, which is based on the identification of a larger number of Main Terraces by several hundred drillings and a correlation of the entire terrace sequence of the Rhine with paleoclimate records, indicates an older age of ca. 1.3 Ma for the Younger Main Terrace. This model implies slower and nearly constant rates of uplift and incision in the Rhenish Massif. To better constrain the uplift and incision history and to decide which model is correct, absolute age determinations for the Main Terraces of the Rhine are required. Such age constraints are, however, still missing. To quantify the history of river incision and uplift of the Rhenish Massif, we will date the most important Main Terraces in the plateau valley of the Rhine by applying 10Be–26Al burial dating. This innovative and still rarely used method allows dating fluvial terrace deposits in the age range of 0.4 to 5 Ma, even if the terraces lack a well-preserved surface due to erosion, deposition of younger cover sediments, and/or anthropogenic influence. As confirmed by our preliminary investigations, the terrace sediments of the Rhine are very well suited for this kind of age dating. The planned project will provide the first absolute time constraints for the Main Terraces along the Rhine at seven carefully selected sites. With these age constraints it will be possible to reconstruct the incision history of the Rhine and the tectonic uplift history of the Rhenish Massif in unprecedented detail and to relate the uplift to geodynamic causes. In particular, clarifying the age of the Younger Main Terrace has far-reaching consequences, because in the past several studies were based on the assumption of an age of 700-800 ka. Therefore, the results of this project will not only be relevant for reconstructing the incision and uplift history of the Rhenish Massif, but also for studies on landscape evolution, mass balances, neotectonics, and time-dependent models for the uplift.