eprintid: 10191340 rev_number: 9 eprint_status: archive userid: 699 dir: disk0/10/19/13/40 datestamp: 2024-04-26 09:22:02 lastmod: 2024-09-03 13:34:23 status_changed: 2024-04-26 09:22:02 type: article metadata_visibility: show sword_depositor: 699 creators_name: Zheng, Zijie creators_name: Chen, Zhong-Qiang creators_name: Grasby, Stephen E creators_name: Wang, Xue creators_name: Papineau, Dominic creators_name: Li, Ziheng creators_name: Wang, Xiangdong creators_name: Zhang, Lei creators_name: Zhao, He creators_name: Huang, Yuangeng creators_name: Feng, Xueqian creators_name: Su, Lewei creators_name: Guo, Zhen title: Carbon-Sulfur isotope and major and trace element variations across the Permian–Triassic boundary on a shallow platform setting (Xiejiacao, South China) ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F57 keywords: Carbon isotope; Sulfur isotope; Element geochemistry; Framboid analysis; Permian–Triassic transition; Mass extinction; Microbialites note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. abstract: We examined microbialites deposited near the Permian–Triassic boundary (PTB) at the Xiejiacao section of South China, including the size and morphology of pyrite framboids, carbonate carbon isotopes (δ13Ccarb), carbonate associated sulfur isotope (δ34SCAS), major and trace elements, and total organic carbon (TOC) concentrations. The microbialite unit is much thicker than the PTB beds in deeper water sections, providing more detailed geochemical records from that time. A prominent negative δ13Ccarb excursion was recognized in association with the second phase of the Permian–Triassic mass extinction (PTME), comparable with that of several other shallow platform facies sections worldwide. δ34SCAS stratigraphic profiles also show a negative excursion, with minimum values occurring slightly later than those of δ13Ccarb. The minimum peak can be calibrated to the middle part of the conodont Isarcicella staeschei Zone, corresponding to the second phase of PTME. Over all, the carbon and sulfur isotopes demonstrate a coupled long-term relationship with large negative excursions during the Permian–Triassic transition followed by gradual recovery in the lowest Triassic, represented an extremely low concentration of sulfate in the ocean during this period. In contrast, the Csingle bondS isotopes are strongly decoupled within the microbialite unit, which could be linked with the oxygen-poor conditions and microbial sulfate reduction (MSR: Sulfate reducing microorganisms facilitated the precipitation of sulfide and carbonate, such as SO42− + 2CH2O → H2S + 2HCO3−). The second phase of PTME was calibrated to the top of the microbialite unit, which was marked by the second δ13Ccarb-δ34SCAS negative excursions. The distinct marine oxygen deficiency was indicated by the small pyrite framboids, relatively high values of UEF (>1) and Ce/Ce* (>0.8). Combined with the previous biostratigraphic work, we propose that continuous volcanic activity induced intensified marine anoxia, leading to biotic mortality in the second phase of the PTME. Overall, our isotopic and geochemical data, integrated with results of previous studies, provided a new explanation for the carbon and sulfur isotope variations and additional evidences into the concurrent environmental changes during the Permian–Triassic transition. date: 2024-07-05 date_type: published publisher: Elsevier BV official_url: https://doi.org/10.1016/j.chemgeo.2024.122115 full_text_type: other language: eng verified: verified_manual elements_id: 2270686 doi: 10.1016/j.chemgeo.2024.122115 lyricists_name: Papineau, Dominic lyricists_id: DPAPI19 actors_name: Papineau, Dominic actors_id: DPAPI19 actors_role: owner full_text_status: restricted publication: Chemical Geology volume: 657 article_number: 122115 issn: 0009-2541 citation: Zheng, Zijie; Chen, Zhong-Qiang; Grasby, Stephen E; Wang, Xue; Papineau, Dominic; Li, Ziheng; Wang, Xiangdong; ... Guo, Zhen; + view all <#> Zheng, Zijie; Chen, Zhong-Qiang; Grasby, Stephen E; Wang, Xue; Papineau, Dominic; Li, Ziheng; Wang, Xiangdong; Zhang, Lei; Zhao, He; Huang, Yuangeng; Feng, Xueqian; Su, Lewei; Guo, Zhen; - view fewer <#> (2024) Carbon-Sulfur isotope and major and trace element variations across the Permian–Triassic boundary on a shallow platform setting (Xiejiacao, South China). Chemical Geology , 657 , Article 122115. 10.1016/j.chemgeo.2024.122115 <https://doi.org/10.1016/j.chemgeo.2024.122115>. document_url: https://discovery.ucl.ac.uk/id/eprint/10191340/1/Zheng_et_al_2024_ChemGeol_Permo-Triassic_C-S_isotopes%2Bgeochem_shallow_platform.pdf