This study presents C and Hg (Hg/TOC) chemostratigraphy data on identified Permian–Triassic successions across the globe with an aim to develop a better understanding on the “mass extinction” event during this time interval. Besides, it would also contribute to the global database on C and Hg stratigraphy and reinforce the application of the latter as a reliable proxy in global correlation, especially in cases of sedimentary sequences deposited coevally with LIP volcanism. In this endeavor, the δ13C chemostratigraphic curves from thousands of kilometers apart from nine classical marine sedimentary sections from various paleolatitudinal zones as well as Hg/TOC stratigraphic pathways of eight of these sections, were examined in a transect across the Pangea supercontinent (~ 252 Ma). A strong negative δ13Ccarb shift at the Late Permian Mass Extinction (LPME), in Meishan D, Guryul Ravine and several other (Permian Triassic Boundary) PTB sections worldwide, is probably due to voluminous CO2 degassing during volcanism in the Siberian Traps Large Igneous Province (STLIP). The C-isotope shift at the LPME is much stronger than in the PTB or Early Triassic Mass Extinction (ETME).