séminaire - lundi 11 juin 2018

Thumbnail imageThe Permian double extinction: Stratigraphy at Chaotian, Sichuan, South China

Masafumi Saitoh

lundi 11 juin 2018, 10 heures, amphithéâtre Guyton de Morveau


Abstract: The Permian mass extinction is characterized by its double-phased nature: the first extinction at the end-Guadalupian (Middle Permian) and the second at the end-Permian. The Guadalupian to lowermost Triassic shelf carbonates of characteristic deep-water facies are continuously exposed in the Chaotian section in northern Sichuan, South China. Litho-, bio-, and chemo-stratigraphy of the two extinction intervals at Chaotian are described. At Chaotian, anoxic deep-water masses emerged prior to the extinction at the end-Guadalupian and at the end-Permian. The intermittently expanded OMZ in the oceans may have contributed to the double extinction.