Latest Permian to Middle Triassic redox condition variations in ramp settings, South China: Pyrite framboid evidence

Abstract

Research Article| January 01, 2017 Latest Permian to Middle Triassic redox condition variations in ramp settings, South China: Pyrite framboid evidence Yuangeng Huang; Yuangeng Huang 1State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan 430074, China Search for other works by this author on: GSW Google Scholar Zhong-Qiang Chen; Zhong-Qiang Chen † 1State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan 430074, China †[e-mail] Search for other works by this author on: GSW Google Scholar Paul B. Wignall; Paul B. Wignall 2School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK Search for other works by this author on: GSW Google Scholar Laishi Zhao Laishi Zhao 3State Key Laboratory of Geological Process and Mineral Resources, China University of Geosciences (Wuhan), Wuhan 430074, China Search for other works by this author on: GSW Google Scholar Author and Article Information Yuangeng Huang 1State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan 430074, China Zhong-Qiang Chen † 1State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Wuhan), Wuhan 430074, China Paul B. Wignall 2School of Earth and Environment, University of Leeds, Leeds LS2 9JT, UK Laishi Zhao 3State Key Laboratory of Geological Process and Mineral Resources, China University of Geosciences (Wuhan), Wuhan 430074, China †[e-mail] Publisher: Geological Society of America Received: 19 Nov 2015 Revision Received: 22 Jun 2016 Accepted: 09 Sep 2016 First Online: 02 Jun 2017 Online Issn: 1943-2674 Print Issn: 0016-7606 © 2016 Geological Society of America GSA Bulletin (2017) 129 (1-2): 229–243. https://doi.org/10.1130/B31458.1 Article history Received: 19 Nov 2015 Revision Received: 22 Jun 2016 Accepted: 09 Sep 2016 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Yuangeng Huang, Zhong-Qiang Chen, Paul B. Wignall, Laishi Zhao; Latest Permian to Middle Triassic redox condition variations in ramp settings, South China: Pyrite framboid evidence. GSA Bulletin 2017;; 129 (1-2): 229–243. doi: https://doi.org/10.1130/B31458.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract A detailed, 10 m.y. redox history of Changhsingian to Anisian (latest Permian to Middle Triassic) oceans in ramp settings is reconstructed based on framboidal pyrite analysis from South China. The result shows that the well-established phenomenon of intense ocean euxinia-anoxia is faithfully recorded in pyrite framboid data. Three major euxinia-anoxia episodes, namely, the end-Changhsingian to end-Smithian, middle to late Spathian, and early to middle Anisian, have been recognized from the ramp successions. The first reducing episode is subdivided into four subepisodes: Permian-Triassic boundary, Griesbachian-Dienerian boundary, earliest Smithian, and end-Smithian. Redox variations broadly track other oceanographic proxies. Euxinia-anoxia episodes coincide with positive excursions of conodont ΩCe anomalies, negative excursions of δ34Scas (carbonate-associated sulfate), increases in sea-surface temperature, and negative excursions of δ13C in most cases. However, euxinia-anoxia near the Dienerian-Smithian boundary coincided with positive excursions of δ13C and a general cooling period. This exception may be the result of locally developed water-column anoxia. The Permian-Triassic boundary subepisode witnessed two ephemeral euxinia-anoxia events separated by a dysoxic to oxic period. The former, together with a rapid increase in sea-surface temperature (up to 8 °C), may have been responsible for the biodiversity crisis, while the latter anoxic event destroyed ecosystem trophic structures. In addition to the Permian-Triassic boundary euxinia-anoxia event, which spread over habitats in all oceans, the Spathian and Anisian euxinia-anoxia episodes also prevailed in global oceans. Variation of the oxygen minimum zone are suggested as the driving mechanism that facilitated the movement of oxygen-poor water columns in various paleogeographic settings over this critical period. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.