Dynamische Modellierung der Andenorogenesek eingebettet in ein 3D Kugelschalenmodell des Erdmantels

安第斯造山作用的一些基本特征不能仅用动态区域模型来解释，因为存在跨越其垂直边界的本质影响。安第斯山脉的动态区域模型应该嵌入到三维球壳模型中。由于爬行速度的极向和环向部分的能量分布，以及沿安第斯山脉的地质决定的质量传输，这两个模型都必须是三维的。我们建立了一个新的地幔粘度剖面，在岩石圈-软流圈交界处有跳跃，深度分别为410、520和660公里。因此，现在对Terra代码的挑战基本上更大了。在过去三年中，我们通过国际合作解决了这些问题(见2.2b)。基于新的粘性分布和改进的Terra模型，我们计算了一个新的正向球壳模型[103,104]。关于改进Terra[56，70]的论文已经提交。我们构思了一个具有相同新粘度剖面的安第斯造山作用的区域模型(3.2b)。我们想要调查为什么在安第斯山脉的一些部分会有平板俯冲，为什么地壳变形和火山活动向东迁移。不相容元素丰度的演化表明，一个循环是由一个快速过程完成的，可能是通过下部板块的大规模分层，也可能是通过另一种类型的分层。结合另一种球壳模型(具有规定的板块边界)，区域模型应该从数值上解释为什么高原型造山带在大洋-大陆板块边界演化。

Some essential features of Andean orogenesis cannot be explained only by a dynamic regional model since there are essential influences across its vertical boundaries. A dynamic regional model of the Andes should be embedded in a 3-D spherical-shell model. Because of the energy distribution on the poloidal and toroidal parts of the creeping velocity and because of geologically determined mass transport alongside the Andes, both models have to be 3-D. We developed a new viscosity profile of the mantle with jumps at the lithospheric-asthenospheric boundary and at a depth of 410, 520 and 660 km. Therefore, the challenges to the code Terra are now essentially larger. In the last three years we have resolved these problems in an international cooperation (see 2.2 b)). Based on the new viscosity profile and on the improved Terra, we computed a new forward spherical-shell model [103, 104]. Papers on the improvement of Terra [56, 70] have been submitted. We conceived a regional model of the Andean orogenesis (3.2 b)) with the same new viscosity profile. We want to investigate why there is flat-slab subduction in some segments of the Andes and why deformation of the crust and volcanism migrate eastward. The evolution of the abundances of incompatible elements indicate a cycle which was finished by a fast process, perhaps by a large-scale delamination of the lower plate, perhaps also by another type of delamination. In connection with another spherical-shell model (with prescribed plate boundaries), the regional model should numerically explain why a plateau-type orogen evolved at an oceanic-continental plate boundary.