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

嵌入地幔 3D 球壳模型中的安第斯造山运动动态建模

基本信息

批准号：
105044687
负责人：
Professor Dr. Jonas Kley
金额：
--
依托单位：
Department of Earth and Planetary Science
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2009
资助国家：
德国
起止时间：
2008-12-31 至 2014-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/105044687?language=en
关键词：
Dynamische Modellierung der Andenorogenesek eingebettet

项目摘要

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.

安第斯造山运动的一些基本特征不能仅用动态区域模型来解释，因为其垂直边界存在重要影响。安第斯山脉的动态区域模型应嵌入 3D 球壳模型中。由于蠕动速度的极向和环形部分的能量分布以及安第斯山脉沿线地质确定的质量传输，两个模型都必须是 3-D 的。我们开发了一种新的地幔粘度剖面，在岩石圈-软流圈边界和 410、520 和 660 km 的深度处具有跳跃。因此，Terra 代码现在面临的挑战实质上更大。在过去三年中，我们通过国际合作解决了这些问题（见 2.2 b））。基于新的粘度曲线和改进的 Terra，我们计算了一个新的正向球壳模型 [103, 104]。关于 Terra 改进的论文[56, 70]已经提交。我们构想了具有相同新粘度剖面的安第斯造山运动区域模型 (3.2 b))。我们想要研究为什么安第斯山脉的某些部分会出现平板俯冲，以及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变表明一个循环是通过快速过程完成的，可能是通过下板的大规模分层，也可能是通过另一种类型的分层。与另一个球壳模型（具有规定的板块边界）相结合，区域模型应该在数值上解释为什么高原型造山带在海洋-大陆板块边界演化。