Seismic tomographic imaging of the crust and upper mantle under the central and western Tien Shan orogenic belt

Seismic tomographic imaging reveals distinct crustal and upper mantle structures beneath the central and western Tien Shan orogenic belt, indicating dynamic geological processes. High-velocity (Vp, Vs) and low Poisson's ratio (σ) anomalies in the upper and middle crust suggest the presence of Paleozoic crystalline basement rocks, while low-velocity and high-σ anomalies in the lower crust and upper mantle imply upwelling of hot, wet material from the mantle. The study also identifies underthrusting of the Tarim and Kazakh lithosphere beneath the Tien Shan, contributing to mountain building. Additionally, a lithospheric-scale boundary is observed along the Talas-Fergana fault, with contrasting seismic structures in central and western Tien Shan, potentially serving as a channel for mantle material to reach the surface.

Lei, J. (2011). Seismic tomographic imaging of the crust and upper mantle under the central and western Tien Shan orogenic belt. Journal of Geophysical Research, 116(B9). https://doi.org/10.1029/2010jb008000