Mesozoic-Cenozoic Deformation of the Central Structure Belt in the Turpan-Hami Basin, Northwest China: Tectonic Evolution of an Intracontinental Basin, Central Asia

摘要

The central structure belt (CSB) in the Turpan-Hami Basin is composed of the Huoyanshan structure and the Qiketai structure, formed in the Late Triassic-Early Jurassic, and is characterized by extensional tectonics. The thickness of strata in the hanging wall of the fault is clearly larger than that in the footwall, and a deposition center evolved in the Taibei sag where the hanging wall of the fault is located. In the Late Jurassic, collision between the Lhasa block and the Eurasia continent resulted in the transformation of the Turpan-Hami Basin from an extensional into a compressional structure, and consequently in the tectonic inversion of the CSB from an extensional normal fault in the earlier stage to a compressive thrust fault in the later stage. Tertiary collision between the Indian and Eurasian plates occurred around 55 Ma, and this Himalayan orogenic event played a profound role in shaping the Tianshan area. However, the effect of the collision on this area was delayed and culminated approximately in Late Oligocene-Early Miocene time. The CSB was strongly deformed and thrust upward as a result of this tectonic event.