Permian – Triassic great extinction and GSSPs of Meishan

These Meishan GSSP sections are the most intensively-studied Lopingian (Upper Permian) and Permian-Triassic boundary sections in the world. The Permian strata contain a highly diverse tropical marine fauna, which includes more than 330 species belonging to 15 different fossil groups (Jin et al., 2000). These sections possess the best record of the end-Permian mass extinction that occurred 251.94 million years ago when more than 81% (formerly ~96%) marine species became extinct within a time interval <61±48 kyr (Burgess et al., 2014). Multiple geochemical records including C, O, Sr, S, Li, Zn, Hg and Ca isotopes have provided proxies for environmental deterioration leading to the extinction. These include a rapid 10°C temperature rise, euxinia and ocean acidification. The sections are correlated using high-resolution conodont and ammonoid biostratigraphic zones and geochronology. More than 30 volcanic ash beds have yielded eight high-precision CA-ID-TIMS dates. Detailed magnetostratigraphy and astronomical cyclostratigraphy also aid correlation. For many decades, the Meishan sections have been widely recognized as the premier location for world-wide correlation of the Permian-Triassic boundary (Yin et al., 2001) and for understanding the biggest Phanerozoic biotic mass extinction (Jin et al., 2000; Shen et al., 2011).