Cenozoic tectonics and geodynamic evolution of the Tien Shan mountain belt

The present-day structure of the Tien Shan mountains consists out of roughly E-W trending, high mountain ranges (exceeding 7000 m), alternating with (near) parallel sedimentary basins. The Tien Shan is situated in Central Asia at the boundary between the active orogenic structures of the northern Tarim plate and the stable Kazakhstan platform (Figure 1). The structural pattern of the Tien Shan indicates a complex Cenozoic deformational history with a current N-S shortening rate of 10-15 mm/yr in the southern Tien Shan and 2-6 mm/yr in the northern Tien Shan. Moreover, shortening vectors from the northern and southern Tien Shan are oriented along different directions. These different shortening rates and orientations can be explained by the presence of the Precambrian Issyk-Kul microcontinent embedded in the northern Tien Shan region. The mosaic-block structure of the Tien Shan mountains is shaped by isometricall