Holocene Activity of the Wudaoliang–Changshagongma Fault of the Eastern Tibetan Plateau

Abstract

The Wudaoliang–Changshagongma fault is one of the NW-trending faults located within the southern Bayan Har Block of the Tibetan Plateau in China. In this paper, we used high-resolution imagery and digital elevation model data to study the geomorphological and geological characteristics of the fault. Furthermore, the result also determined the fault trace and estimated the average horizontal slip rate of the fault since the late Quaternary to have been 2.6 ± 0.6 mm/a. This slip rate is approximately equivalent to that of the Awancang, Madoi–Garde, and Dari faults, which are also located within the block. Furthermore, the slip rates of these faults obtained by remote sensing and geological methods are consistent with GPS observations. It indicates that tectonic deformation within the block is continuous and diffuse. Using trenching study results and sedimentary radiocarbon dating, we identified four paleoearthquake events that occurred at 42,378–32,975, 33,935–20,663, 5052–4862, and after 673–628 cal BP, respectively. The recurrence intervals of large earthquakes on the faults within the block are much longer than those of the boundary faults, and the slip rates are also smaller, indicating that faults within the block play a regulatory role in the tectonic deformation of the Bayan Har Block.

Holocene activity and seismic surface rupture zone of the Abuduo fault eastern Tibetan Plateau

“…Historically, a number of strong earthquakes have occurred on this fault, e.g., the M8.0 earthquake in Manigange, Sichuan Province (1320), Ms7.5 earthquake in Dangjiang, Qinghai Province (1738), and Ms7.7 earthquake in Garzê, Sichuan Province (1854) (Zhou et al, 1997;Lin et al, 2011;Li et al, 2016;Lv et al, 2017). Latest research on the middle section of the NW-trending Wudaoliang-Changshagongma fault within the Bayan Har block indicates that it is a left-lateral strike-slip fault with Holocene activity that has had an average horizontal slip rate of 2.55 ± 0.50 mm/a since the Late Quaternary, and four paleoseismic events have been revealed by trench survey (Liang et al, 2022;Liang et al, 2023). Among the three near E-W-trending faults within the study area, the Batang fault is a left-lateral strike-slip fault with Holocene activity that has had a horizontal slip rate of 2.1-3.9 mm/a since the Late Quaternary, and presents a paleoseismic recurrence cycle of approximately 1,500 years (Huang et al, 2015;You et al, 2016).…”