Quantifying fluvial and glacial erosion using detrital thermochronology, cosmogenic nuclides and numerical modelling: a case study in the European Alps

使用碎屑热年代学、宇宙成因核素和数值模型量化河流和冰川侵蚀：欧洲阿尔卑斯山的案例研究

• 批准号: 219522370
• 负责人: Dr. Christoph Glotzbach
• 金额: --
• 依托单位: Institut for Geoscience
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/219522370?language=en
• 关键词: Quantifying; fluvial; glacial; erosion; using

Mountain landscapes result from the interplay between tectonics, climate and erosion. Climate changes can noticeably influence erosion, especially if significant variations in the equilibrium line altitude (ELA) of glaciers occur, leading to changes in the location and style of erosion (fluvial vs. glacial erosion). In this project we will use cosmogenic nuclides and thermochronology accompanied by numerical modelling to quantify the evolution of alpine landscapes over several glacial-interglacial cycles. The study area is located in the central Swiss Alps in the Aare valley, for which an approximately 10-fold increase in valley incision caused by glaciations since ~0.9 Ma has been documented. Associated spatial variations in erosion rates will be quantified with detrital thermochronology applied to present-day streams and glacial sediments from surface and cave deposits. Measured age distributions will be statistically interpreted with respect to bedrock thermochronological age distributions of the source area to estimate relative erosion rate maps. Catchment-wide denudation rates measured with cosmogenic nuclides on same stream sediments and published palaeo-denudation rates from cave deposits serve to transform relative erosion rate maps to absolute rates. Furthermore, detrital thermochronological results will be used to calibrate numerical surface process models. This multi-methodological approach will give important information about landscape evolution (e.g. relief change) of alpine settings during Quaternary climate change.

山地地貌是地质构造、气候和侵蚀相互作用的结果。气候变化可以显著影响侵蚀，特别是如果冰川的平衡线高度发生重大变化，导致侵蚀的位置和方式发生变化（河流侵蚀与冰川侵蚀）。在这个项目中，我们将使用宇宙成因核素和热年代学伴随着数值模拟来量化几个冰川间冰期循环的高山景观的演变。该研究区位于瑞士阿尔卑斯山中部的Aare山谷，据记载，自0.9 Ma以来，冰川造成的山谷切口增加了约10倍。相关的侵蚀率的空间变化将量化与碎屑热年代学适用于当今的溪流和冰川沉积物的表面和洞穴沉积。测量的年龄分布将进行统计解释相对于基岩热年代学年龄分布的源区估计相对侵蚀率地图。全流域的剥蚀率测量宇宙成因核素在相同的流沉积物和公布的古剥蚀率洞穴沉积物的相对侵蚀速率图转化为绝对速率。此外，碎屑热年代学结果将用于校准数值表面过程模型。这种多方法的方法将提供重要的信息景观演变（如地形变化）的高山设置在第四纪气候变化。