Kinetics and Dynamics of Development of the Dabie–Sulu Uhpm Terranes Based on Geophysical Evidences

Abstract

AbstractThe Dabie–Sulu region, located in the east part of the central orogenic belt of China, has the largest ultrahigh pressure metamorphic (UHPM) zone in the world. Based mainly on geophysical data newly obtained in the region, this paper shows the sophistication of the evolution and dynamics of the Dabie–Sulu UHPM belt. The subduction of the Dabie–Sulu terranes after collision between the Sino‐Korean and Yangtze cratons induced the ultrahigh pressure metamorphism. A local extension occurred in Dabie‐Sulu region after the subduction, yielding good conditions for exhumation of the UHPM rocks. The local extension was the result of Yangtze rotation that was generated by the oblique impact between the two cratons. The Yangtze rotation might also provided a pair of shear forces on bottom of the lithosphere to make a breakoff event that is essential to the exhumation of the UHPM terranes. Owing to continuing convergence between the two cratons after the exhumation of Dabie‐Sulu UHPM terranes, Yangtze craton proceeded to subduct beneath the Dabie‐Sulu terranes and the Sino‐Korean craton. This intracontinental subduction carried tremendous mass of crustal materials into the upper mantle, causing later partial melting, mantle doming and rifting. Based on above‐mentioned analysis, the previous models for evolution of the Dabie–Sulu terranes are elaborated.