DEXTRAL TRANSPRESSIONAL DEFORMATION OF MESOZOIC HEILONGJIANG ACCRETIONARY COMPLEX OF NE CHINA: AN OBLIQUE SUBDUCTION OF PACIFIC OCEAN

In Northeast China, the blueschists-bearing Heilongjiang Complex has been considered as a Mesozoic accretionary complex associated with the subduction of the Pacific ocean and their kinematic evolution remains controversial. In this study we present a detailed structural analysis of the HP Heilongjiang complex in the central part of the Heilongjiang complex, located near Yilan city. Detailed 2D and 3D finite strain analyses were carried out for five structural domains of the Yilan area. These structural and strain analyses leads us to propose that the linked E-W and NE-directed and dextral strike-slip zone highlighted in the Yilan area occurred within a dextral transpressional tectonic regime. The paleo-convergence orientation was deduced from the obtained results, indicating a transition from an SE-ESE to E-directed paleo-convergence. In addition, our study emphasizes the synchronicity between the ductile strain developments related to the HP Heilongjiang complex and the development of the NE-directed dextral Yilan-Yitong strike-slip fault, which was previously considered as a sinistral fault. Therefore our work has demonstrated that the kinematics of the Mesozoic Heilongjiang complex in the Yilan area of NE China indicate a dextral accretionary orogenesis in northeast Asia as a result of an oblique subduction of the Pacific Ocean.