Guadalupian (Middle Permian) ocean redox evolution in South China and its implications for mass extinction Wei, Hengye ; Tang, Zhanwen ; Yan, Detian ; Wang, Jianguo ; Roberts, Andrew P. Abstract Publication: Chemical Geology Pub Date: December 2019 DOI: 10.1016/j.chemgeo.2019.119318 Bibcode: 2019ChGeo.53019318W