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

通过使用 10Beâ26Al 埋葬测年方法对莱茵河谷河流阶地进行测年，量化莱茵河地块的河流切入和隆起

• 批准号: 525049675
• 负责人: Professor Dr. Ralf Hetzel
• 金额: --
• 依托单位: Institut für Geologie und Paläontologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/525049675?language=en
• 关键词: Quantifying; river; incision; uplift; Rhenish

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.

对于保存完好的河流序列序列的区域，Rhenish massif是一个突出的例子。这些露台是由莱茵河及其支流切入古生代基岩形成的。所谓的年轻主要露台上方最年轻的露台上方最年轻的露台构成了重要的地貌标记，因此，基于古磁数据，假定该年龄为700-800 ka。使用这个时代和莱茵河上方的年轻主要露台的高度，开发了一种河流切口和隆起的模型，这预测切口速度突然增加，并在700-800 ka上升高。相比之下，一个替代模型基于对较大的主要梯田的识别，并通过数百个钻孔以及莱茵河与古气候记录的整个露台序列的相关性相关，表明Ca的年龄较大。 1.3 MA对于年轻的主要露台。该模型意味着在莱茵泥浆中的隆起和切口较慢，几乎恒定的速率。为了更好地限制升高和切口历史记录并确定哪种模型是正确的，需要对莱茵河主要露台的绝对年龄确定。但是，这种年龄限制仍然缺失。为了量化Rhenish Massif的河流切口和隆升的历史，我们将通过施加10BE-26AL埋葬日期来与莱茵省高原谷最重要的主要露台约会。这种创新且仍然很少使用的方法允许年龄范围为0.4至5 mA的河露台沉积物，即使梯田由于侵蚀，年轻覆盖沉积物的沉积和/或人为影响而缺乏保存完好的表面。正如我们的初步调查所证实的那样，莱茵河的露台沉积物非常适合这种年龄约会。计划的项目将在七个精心挑选的地点沿莱茵河沿莱茵河的主要露台提供第一个绝对时间限制。借助这些年龄限制，可以通过前所未有的细节重建莱茵河的切口历史和莱茵派弥撒的构造隆起历史，并将其与地球动力学原因联系起来。特别是，澄清年轻的主要露台的年龄具有深远的后果，因为在过去的几项研究中，基于700-800 ka的假设。因此，该项目的结果不仅与重建莱茵什锦泥的切口和隆升历史有关，还与景观演化，质量平衡，新遗传学以及抬高的时间依赖性模型有关。