Geoscience

Discovery of Permian-Triassic Wildfire Records

There were dramatic changes in the environment at the end of the Permian with the largest mass extinction in the Earth’s history. The combustion-derived polynuclear aromatic hydrocarbons (PAHs) and black carbon (BC) were discovered in the Meishan Permian-Triassic (P-Tr) sediments by Postdoctoral researcher Shen Wenjie and his tutor Lin Yangting from the Institute of Geology and Geophysics, CAS. And such materials showed the largest peak coinciding with the event beds (beds 25 and 26). For the first time, these researchers clearly proposed the P-Tr wildfire hypothesis in accordance with the remains of carbonaceous materials combustion. Research on the high-resolution integrated profile indicated that the wildfire occurred coinciding with the marine anoxia, intensive volcanic activity and marine mass extinction, which shows their cause-effect relationship. Wildfire, as an event on land, was probably an indicator of land mass extinction (direct but not the final cause), while the intensive volcanic activity could be the final cause for the great P-Tr environmental change and mass extinction. This research has recently published in Geochimica et Cosmochimica Acta (Shen et al. Evidence for wildfire in the Meishan section and implications for Permian-Triassic events. Geochimica et Cosmochimica Acta. 2011, 75: 1992-2006).