Synchronized changes in shallow water carbonate production during the Carnian Pluvial Episode (Late Triassic) throughout Tethys

Quantitative petrologic analysis on carbonates was carried out on stratigraphic sections encompassing the Carnian Pluvial Episode from northwestern Sichuan Basin, South China and eastern Southern Alps. The Carnian Pluvial Episode, or CPE, is a period of climate change that occurred between the early Carnian and the beginning of the late Carnian (Late Triassic) and coincides with multiple, sharp negative excursions in the record of δ13C that are thought to be evidence of perturbations of the global carbon cycle. During the CPE, relevant environmental modifications and biological turnovers occurred in the marine realm. In particular, microbial carbonate platforms, that were dominant in northwestern Sichuan Basin and throughout Tethys, underwent widespread demise and the microbial component in shelf carbonate sediments sharply decreased and was replaced by ooid- and skeletal grains. Our results show a Tethys-wide coincidence between this change in the carbonate factory. Most notably, both in eastern and western Tethys microbial carbonate production recovered in the late Tuvalian, and the timing of recovery was not influenced by differences of basin evolution and geodynamic setting that characterize such distant domains.