Neogene Paleoelevation and Paleoclimate of the Central Alps - Linking Earth Surface Processes to Lithospheric Dynamics

中央阿尔卑斯山的新近纪古海拔和古气候 - 将地球表面过程与岩石圈动力学联系起来

• 批准号: 365266215
• 负责人: Professor Dr. Todd Alan Ehlers
• 金额: --
• 依托单位: School of Geographical and Earth Sciences
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/365266215?language=en
• 关键词: Neogene; Paleoelevation; Paleoclimate; Central; Alps

This project integrates stable isotope altimetry records (d18O/dD) of the Central Alps with a high-resolution, global, isotope tracking paleoclimate model. We envisage testing between different Miocene to present surface uplift scenarios driven by lithospheric scale geodynamic processes inferred from AlpArray seismic imaging. For instance, if true that accretion of crustal material to the overriding plate results in short-wavelength orogen uplift and foreland basin subsidence, we would expect to see a steady increase in the change of oxygen isotopes in precipitation as a function of elevation, Delta(d18O), or Delta(z) between high Alpine regions and the foreland over time. In contrast, if the opening of slab gaps, slab breakoff, and subduction polarity reversals produce long-wavelength uplift signals affecting both the orogen and its foreland, the resulting changes in surface elevation might be more variable in time and result in a Delta(d18O) = 0 (if foreland and high-alpine elevations increased in a similar manner). However, in the latter case absolute changes in d18O can be expected. Testing these hypotheses requires a multidisciplinary approach involving tools that go beyond the methods commonly employed in stable isotope paleoaltimetry. We address this challenge through an integration of isotope-enabled paleoclimate models (ECHAM5-wiso) with new paleoclimate proxies (stable isotope and clumped isotope studies) collected from the foreland basin and high-elevation regions of the Alps. These experiments will bridge spatial and temporal scales of environmental change over the Alps, thereby forming a baseline for evaluating past climate influences on paleoaltimetry, erosion and exhumation studies across the AlpArray study area. Furthermore, establishing a surface elevation record will inform the debate about the timing of slab inversion and/or tearing in the Western Alps, and serve as a point of reference for thermochronology and geo-dynamic modelling studies that investigate the coupling between tectonics and erosion, and the crust-mantle processes responsible for shaping the European Alps. This study directly contributes to Research Themes 1, 2, 3 and Activity Fields E, F of the 4D-MB priority research program.

该项目将中央阿尔卑斯山的稳定同位素测高记录(d18O/dd)与高分辨率的全球同位素跟踪古气候模型相结合。我们设想在不同的中新世之间进行测试，以呈现由阿尔普阵列地震成像推断的岩石圈尺度地球动力学过程驱动的地表隆起情景。例如，如果地壳物质对上覆板块的吸积导致短波造山带隆起和前陆盆地下沉，我们预计随着时间的推移，降水中氧同位素的变化将作为海拔、高阿尔卑斯山地区和前陆之间的增量(D18O)或增量(Z)的函数而稳步增加。相反，如果板片缝隙的打开、板片断裂和俯冲极性反转产生了影响造山带及其前陆的长波隆起信号，那么由此产生的地表高度的变化可能在时间上更可变，并导致Delta(D18O)=0(如果前陆和高高山海拔以类似的方式增加)。然而，在后一种情况下，d18O的绝对变化是可以预期的。检验这些假说需要一种多学科的方法，涉及的工具超越了稳定同位素古高度学中通常使用的方法。我们通过将同位素启用的古气候模型(ECHAM5-WISO)与从前陆盆地和阿尔卑斯山高海拔地区收集的新的古气候替代物(稳定同位素和块状同位素研究)相结合来应对这一挑战。这些实验将连接阿尔卑斯山环境变化的空间和时间尺度，从而形成评估过去气候对整个阿尔卑斯山研究区域的古测高、侵蚀和挖掘研究的影响的基线。此外，建立表面高程记录将为关于西阿尔卑斯山板块反转和/或撕裂时间的辩论提供信息，并作为热年代学和地球动力学模拟研究的参考点，这些研究调查构造和侵蚀之间的耦合，以及负责形成欧洲阿尔卑斯山的壳幔过程。这项研究直接对4D-MB优先研究计划的研究主题1、2、3和活动领域E、F作出贡献。