Initial formation and mesozoic tectonic exhumation of an intracontinental tectonic belt of the northern part of the Taihang Mountain Belt, eastern Asia

摘要

The NNE-trending Taihang Mountain belt, North China, is an intracontinental anomalous zone with a significant magmatic and gravity signature. From structural investigations, U-Pb dating, and Ar-40/Ar-39 chronological analyses, a three-stage tectonic evolution sequence can be reconstructed for the northern part of the Taihang Mountain belt during the middle to late Mesozoic period. This sequence comprises a WNW-ESE-directed compression that occurred at 175-150 Ma, followed by magmatic intrusions (146-142 Ma) and ending with the emplacement of alkaline granitic intrusions and their exhumation at 142-120 Ma. Normal faulting during late Cretaceous-Cenozoic time exposed the Taihang Mountains. The earlier compressional deformation and the following volcanic and magmatic episodes were probably controlled by some far-field stress release associated with the subduction of the paleo-Pacific plate beneath the eastern Asian continent. After the orogeny, the structural evolution, sedimentation, and tectonic settings on the western side differ from those on the eastern side of the Taihang Mountain belt.