Surface deformation and tectonic implication of the late Quaternary Bue Co strike-slip fault system, mid-western Qiangtang block

The Bangong Lake-Nujiang Suture Zone (BNSZ) serves as a significant boundary within the Tibetan Plateau, separating the Qiangtang and Lhasa terranes. Studying the late Quaternary geometric structure and deformation characteristics of (conjugate) strike-slip faults in this boundary zone is crucial for gaining a better understanding of the spatial responses and tectonic model resulting from the collision of the Indo-Eurasian plates . The Bur Co fault system, located in the western BNSZ, consists of the NE Bur Co Fault and the NW Lamu Co Fault. By employing remote sensing interpretation and conducting field geological investigations, researchers have clarified the late Quaternary structural and surface deformation characteristics of these two faults. The results demonstrate significant fault activity since the late Quaternary period, with evidence of recent large earthquakes causing surface ruptures along both faults. Consequently, it can be inferred that the recent active intensity of the NW and NE faults in the western part of the BNSZ might be similar. Furthermore, it is likely that the current deformation of the southern boundary of the Qiangtang Block is influenced by both faults, which has extended into the internal of the block. These findings provide further support for the hypothesis that the material within the Tibetan Plateau continues to expand eastward and northward due to the activity of strike-slip faults and normal faults, driven by the weaken mid-lower crustal flow.