Active tectonics and paleo-earthquakes in north Yumu Shan, northern Tibetan Plateau: Insights from structural analysis and radiocarbon dating

The Yumu Shan is located at the northern margin of Tibetan Plateau in northwest China. It characterized by development several northeastward-protruding arcuate geomorphic bulge belts on its north slope. These are distributed along Wutongquan spring, ancient Camel City, and Xiaogengzi area, south to Gaotai City Hexi Corridor. In this study, our detailed field mapping structural analysis reveal northeastward active anticline folding curved related lacustrine sediments their hinterlands. Radiocarbon dating plant charcoal samples from sedimentary layers yields a 14 C age AD 178 ± 42. This close time 180AD/Ms7.5 earthquake Biaoshi (i.e., Zhangye City) during Eastern Han Dynasty. similarity between seismic events leads us infer that layer records major flood event earthquake. We propose fault-related fold model for formation sediments. First, series historical activities Holocene, especially earthquake, may have led blind thrust faulting plateau. Then, thrusting resulted folding, causing bulges. latter acts as flood-retaining dam, resulting hinterland deposition For reason, we suggest seismogenic responsible uplift northward growth Plateau. As northernmost Fault could be considered North Boundary Thrust (NBT), which defines exactly