Quantifying the Effects of Mantle Processes and Climate Variability on HinterlandDenudation in the Central and Eastern Alps since the Oligocene

现今的阿尔卑斯莫霍面断层摄影图确定了两个残留的地幔岩石圈板在中部到东部阿尔卑斯山下约。135-165 km深度，大约沿亚得里亚海沿岸走向。这一观察导致了新的假设地幔过程和地幔岩石圈板几何的欧洲和亚得里亚海板块，因为最初的大陆碰撞在渐新世。例如，板片断裂事件被提议为渐新世和早/中中新世，随后是俯冲极性反转。它们对地表过程的潜在影响，即对保存在中新世地层记录和现今基岩中的腹地剥蚀的影响，将是本提案的主要重点。我们将利用沿着NFP-20 E，TRANSALP和EASI剖面创建的二维运动学场来重建阿尔卑斯山脉中部至东部的三维运动学历史，并将其作为最先进的数值景观演化/表面过程模型（LEM）的输入。通过测试一系列的幅度和波长的地幔引起的表面隆起，添加到这个“基线”的三维运动学领域，我们将能够量化地幔过程的影响，腹地剥蚀通过侵蚀通量，基岩和碎屑热年代学数据建模。为了区分地幔和气候造成的影响，例如，中新世气候最佳，我们的LEMs将受到空间和时间变化的降水。在LEMs中模拟的内陆剥蚀，包含地幔和气候成分，将与现有的现今基岩和中新世地层碎屑热年代学数据进行比较，以评估是否有任何拟议的地幔过程导致可观察到的表面响应。我们新颖的地幔-地表数值模拟方法不仅继续了我们在MB-4D SPP第一阶段的工作，而且直接解决了第二阶段的主题2。

Present-day tomographic mapping of the Alpine Moho identified two remnant mantle lithospheric slabs beneath the Central to Eastern Alps at ca. 135-165 km depth approximately along-strike the Periadriatic Lineament. This observation led to new hypotheses on mantle processes and mantle lithospheric slab geometries of the European and Adriatic plates since initial continental collision during the Oligocene. For example, slab break-off events are being proposed for the Oligocene and Early/Middle Miocene followed by subduction polarity reversal. Their potential influence on surface processes, i.e. hinterland denudation, preserved in the Miocene stratigraphic record and present-day bedrock will be the main focus of this proposal. We will take advantage of 2D kinematic fields created along the NFP-20E, TRANSALP and EASI profiles to reconstruct the 3D kinematic history of the Central to Eastern Alps and use this as input to state-of-the-art numerical landscape evolution / surface processes models (LEMs). By testing a range of magnitudes and wavelengths of mantle-induced surface uplift, added to this ‘baseline’ 3D kinematic field, we will be able to quantify the effect of mantle processes to hinterland denudation through modelling of erosional flux, bedrock and detrital thermochronological data. In order to distinguish mantle and climatic effects caused, for example, by the Miocene Climatic Optimum our LEMs will be subject to spatially and temporally variable precipitation. Hinterland denudation modelled in LEMs that contain both, mantle and climate components, will be compared to existing present-day bedrock and Miocene stratigraphic detrital thermochronologic data to evaluate whether any of the proposed mantle processes resulted in an observable surface response. Our novel mantle-to-surface numerical modelling approach not only continues our work during the first phase of the MB-4D SPP but also directly addresses its second phase Theme 2.