Numeric modeling of the Cenozoic Pamir-Tien Shan orogen

我们建议在地质和地球物理观测的约束下，利用先进的数值模拟方法研究帕米尔-天山地区新生代变形样式的控制因素。该项目由两个紧密联系的主题组成。主题(I)将侧重于上地幔和地壳动力学在亚洲和印度板块形变和应变局部化中的作用。这些模型将研究(I)俯冲的印度板块和俯冲的亚洲板块内的不均匀温度和成分分布的影响；(Ii)前进的印度板块尖端附近应力集中的三维影响；以及(Iii)下地壳和岩石圈下地幔流动的可能影响。专题(Ii)将侧重于地表侵蚀和沉积的影响，并将特别考虑(I)帕米尔两侧的侵蚀在促进地壳下部流动方面的作用，(Ii)侵蚀的机械削弱效应及其对应变局部化和该地区整体构造力平衡的影响。所有模型都将采用高度非线性的粘弹塑性流变学，允许自洽地生成断层，并将首先在2D+时间内进行，然后在3D+时间内进行。最后，这两个主题的模型将结合起来，既包括深层过程，也包括表层过程。联合模式将用于综合在TIPAGE其他项目中收集的观测数据，并与在INDEPTH IV项目中为西藏地区获得的模式进行比较。

We propose to study factors controlling styles of Cenozoic deformation in the Pamir–Tien Shan region using advanced numerical modeling constrained by geologic and geophysical observations. The project consists of two closely linked themes. Theme (I) will focus on the role of the upper mantle and crustal dynamics in deformation and strain localization in the Asian and Indian plates. The models will address (i) effects of heterogeneous temperature and compositional distribution within the subducting Indian plate and overriding Asian plate; (ii) 3D effects of stress concentration around the tip of the advancing Indian plate, and (iii) possible effects of lower crustal and sub-lithospheric mantle flows. Theme (II) will focus on the effects of surface erosion and sedimentation and will particularly consider (i) the role of erosion at the Pamir flanks in the promotion of the lower crustal flow and (ii) the mechanical weakening effect of erosion and its impact on strain localization and on the overall tectonic force balance in the region. All models will employ highly non-linear visco-elasto-plastic rheology, allowing for self-consistent generation of faults and will be first conducted in 2D + time and then in 3D + time. Finally, models of both themes will be joined to include both deep and surface processes. The joint models will be used for integration of the observations collected in the other TIPAGE projects and for comparison with the models obtained for the Tibet region within the INDEPTH IV project.