POST-OROGENY AND INTRACONTINENTAL DEFORMATION IN THE WEST QINLING-DABIE OROGENIC BELT: CONSTRAINED BY STRUCTURAL INVESTIGATION AND SEDIMENTARY ANALYSIS

Plate tectonics theory suggests that deformation occurs mainly along plate boundaries, however, intracontinental compression contributes to the formation of the intracontinental orogens and basin formations, which then can constrain the continental marginal tectonic events. The Jurassic and Cretaceous deformation and basin formation along the south edge of the Qinling-Dabie orogenic belt has been considered as the continued collision between the North China and Yangtze plate. Study of the structures, sedimentary sequences and detrital zircon ages have been taken place along the fronts of the Longmenshan, Micang and Daba tectonic belts. The Lower Jurassic conglomerate shows the near-source, up-piled and non-syn-thrusting sedimentation. The Lower Cretaceous conglomerate and sandstone are with far-source and syn-thrusting sedimentation. They were responded to the post-orogenic south-vergent thrust deformation and syn-southeastward and southward thrust deformation along the Longmen and Mica-Daba tectonic belts during the Late Jurassic-Early Cretaceous. These deformation and basin formation are belonged to the intracontinental tectonic events, but not the continued collision events.