The Late Triassic and Late Jurassic stress fields and tectonic transmission of North China craton

摘要

The transmission of the tectonic regime from the Paleo-Asian Ocean to the Pacific Ocean during Meso-zoic era was reconstructed using the modeling of Late Triassic (T_3) and Late Jurassic (J_3) stress fields employing two dimensional linear finite element models (2-D FEM). The model at T_3 proposes that Qinling-Dabie-Sulu orogens coevally collided and the model J_3 proposes that Subei block continued to collide with the North China block along the Sulu orogen while the collision of the Qinling-Dabie oro-gen was terminated. The stress fields at T3 and J_3 during the two episodes were calculated based on mechanical conditions under different deviatoric stresses acting along the boundaries of the North China craton by elastic finite modeling. The transmission between two episodes of stress fields resulted from Qinling-Dabie-Sulu collision between North China and South China in the Late Triassic period, and from continued collision between the Subei block and North China by the NW-trending movement of Izanagi plate during Late Jurassic. The results from modeling of the Mesozoic stress fields of the North China suggest that late Jurassic was the key transmission period of the tectonic regime of the North China block when large scale thrusting triggered the subsequent destruction of the North China craton.