“…The Upper Permian to Lower Triassic of South China is characterized by the widespread occurrence of volcanic ash layers (Gao et al, 2013;He et al, 2014;Yang et al, 2012), permitting precise and accurate U-Pb zircon geochronological calibrations of Permian-Triassic successions (e.g., Baresel et al, 2017aBaresel et al, , 2017bBurgess et al, 2014;Lehrmann et al, 2015;, as well as providing a means of evaluating the provenance of volcanic products (e.g. zircon) to sedimentary successions in South China (e.g., Jiao et al, 2022;Zhao et al, 2019). However, except for the Shangsi section (S. Shen et al, 2011), Hg anomalies recorded near the PTB from deep-water marine settings in South China lack U-Pb zircon age calibration.…”