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

该项目将中阿尔卑斯地区稳定同位素测高记录（d18O/dD）与高分辨率全球同位素追踪古气候模式相结合。我们设想在不同中新世之间进行测试，以呈现由AlpArray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，如果地壳物质向覆岩板块的增加导致短波长的造山带隆起和前陆盆地沉降，我们就可以预期，随着时间的推移，高阿尔卑斯地区和前陆之间的δ (d18O)或δ (z)随海拔的变化，降水中氧同位素的变化会稳步增加。相反，如果板块裂口的打开、板块断裂和俯冲极性反转产生影响造山带及其前陆的长波隆升信号，则地表高程的变化可能随时间变化更大，并导致三角洲(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，可以预期d18O的绝对变化。要验证这些假设，需要采用多学科方法，使用的工具要超越稳定同位素古测高常用的方法。我们通过将同位素古气候模型（ECHAM5-wiso）与从阿尔卑斯山前陆盆地和高海拔地区收集的新古气候代用物（稳定同位素和团块同位素研究）相结合来解决这一挑战。这些实验将跨越阿尔卑斯山脉环境变化的时空尺度，从而形成一个基线，用于评估过去气候对整个AlpArray研究区域的古高程测量、侵蚀和挖掘研究的影响。此外，建立一个地表高程记录将为关于西阿尔卑斯山板块反演和/或撕裂时间的争论提供信息，并作为热年代学和地球动力学建模研究的参考点，研究构造和侵蚀之间的耦合，以及负责塑造欧洲阿尔卑斯山的地壳-地幔过程。本研究直接贡献于4D-MB优先研究计划的研究主题1、2、3和活动领域E、F。

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.