Reconstructing Eastward Propagation of Surface Uplift in the Alps: Integrating Stable Isotope Palaeoaltimetry and Palaeoclimate Modelling

拟议的项目检验了一种假设，即阿尔卑斯山西部/中部和东部之下的板片断裂和板片撕裂从西向东传播产生了类似的地表隆起传播，使得西部/中部阿尔卑斯山比东部阿尔卑斯山更早到达更高的海拔(SPP主题1和2)。我们的第一阶段工作记录了中央阿尔卑斯山中中新世的高海拔，在第二阶段，我们将我们的跨学科方法扩展到西阿尔卑斯山/东阿尔卑斯山，以评估地表抬升是否历时。我们通过几种方法的整合来做到这一点：(1)δ-δ古测高方法的新样品，包括渐新世至中新世盆地沉积的稳定同位素测量(δ18O，δD，∆47-∆48)，将从阿尔卑斯山西部和东部以及沿上风汽源轨迹(西班牙，法国)收集，以便与我们从中央阿尔卑斯山(第一阶段)的结果进行比较。(2)同位素追踪大气环流模式(GCM)将被用来预测与样本年龄重叠的时间段的古气候，并量化不同西向东向地形配置的影响。需要气候模拟来校正观测到的稳定的古气候同位素替代记录，并分离地表隆起信号，从而能够重建阿尔卑斯山西部与东部阿尔卑斯山地表隆起的历史。这一综合方法的结果将被用来确定4DMB的地球动力学模型和地震分量所记录的板片断裂和撕裂由西向东的传播是否导致了阿尔卑斯山西部和东部的历时地表隆起历史。

The proposed project tests the hypothesis that the west-to-east propagation of slab breakoff and slab tearing under the Western/Central to Eastern Alps produced a similar propagation in surface uplift, so that the Western/Central Alps reached higher elevations earlier than the Eastern Alps (SPP Themes 1 and 2). Our Phase 1 work documented high middle Miocene elevations in the Central Alps, and in this 2nd phase we extend our interdisciplinary approach to the Western/Eastern Alps to evaluate if surface uplift was diachronous. We do this through an integration of several methods: (1) New samples for the δ-δ palaeoaltimetry approach, including stable isotope measurements (δ18O, δD, ∆47-∆48) on Oligocene to Miocene basin deposits, will be collected from the Western and Eastern Alps and along upwind vapor source trajectories (Spain, France) for comparison to our results from the Central Alps (Phase 1). (2) An isotope tracking atmospheric General Circulation Model (GCM) will be used to predict palaeoclimates for time periods that overlap with sample ages, and to quantify the effects of different west-to-east topographic configurations. Climate modelling is required to correct observed stable isotope proxy records for palaeoclimate and isolate the surface uplift signal, thereby allowing the reconstruction of Western vs. Eastern Alps surface uplift histories. The outcomes of this combined approach will then be used to determine if suggested west-to-east propagation of slab breakoff and tearing documented from geodynamic modelling and seismic components of 4DMB resulted in a diachronous surface uplift history of the Western and Eastern Alps.