Numeric modeling of the Cenozoic Pamir-Tien Shan orogen

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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.