Mesozoic large-scale lateral extrusion, rotation, and uplift of the Tongbai-Dabie Shan belt in east China

摘要

The tectonic convergence between the South China block and Qinling belt that occurred in Mesozoic time was not homogeneous along strike; it was mainly concentrated in the Shengnongjia and Hannan domes, which formed a pair of indentors, along which the South China block penetrated the Qinling belt. As a consequence, the Tongbai–Dabie Shan belt, the eastern part of the Qinling orogenic belt, may have undergone large-scale eastward extrusion, clockwise rotation, and uplift, as indicated by its boundary deformation features. It was originally located beneath the narrowest part of the Qinling belt, where it underwent ultrahigh-pressure metamorphism in the Early Triassic.