Timing and Provenance of Volcanic Fluxes Around the Permian‐Triassic Boundary Mass Extinction in South China: U‐Pb Zircon Geochronology, Volcanic Ash Geochemistry and Mercury Isotopes

Bibliographic Details
Title: Timing and Provenance of Volcanic Fluxes Around the Permian‐Triassic Boundary Mass Extinction in South China: U‐Pb Zircon Geochronology, Volcanic Ash Geochemistry and Mercury Isotopes
Authors: Oluwaseun Edward, André Navin Paul, Hugo Bucher, Christian Vérard, Thierry Adatte, Jeroen E. Sonke, Urs Schaltegger, Torsten Vennemann
Source: Geochemistry, Geophysics, Geosystems, Vol 24, Iss 6, Pp n/a-n/a (2023)
Publisher Information: Wiley, 2023.
Publication Year: 2023
Collection: LCC:Geophysics. Cosmic physics
LCC:Geology
Subject Terms: volcanism, mass extinction, mercury isotopes, U‐Pb geochronology, Permian‐Triassic boundary, South China, Geophysics. Cosmic physics, QC801-809, Geology, QE1-996.5
More Details: Abstract Anomalous mercury (Hg) contents recorded near the Permian‐Triassic boundary (PTB) are often linked to Siberian Traps Large Igneous Province (STLIP) volcanism and the Permian‐Triassic boundary mass extinction (PTBME). However, mounting evidence indicates that the relation between STLIP volcanism and Hg “anomalies” is not straightforward. This study focuses on the timing and provenance of volcanic fluxes around the PTBME in South China. We constrain carbon isotope (δ13C) and Hg concentration and isotope records by utilizing high‐precision U‐Pb zircon ages from two expanded deep‐water marine sections spanning the Late Permian to Early Triassic in the Nanpanjiang Basin. Results reveal two episodes of Hg enrichment. The oldest episode predates the onset of a large negative δ13C excursion, which is documented to be older than 252.07 ± 0.130 Ma. The second episode occurred between 251.822 ± 0.060 and 251.589 ± 0.062 Ma, coinciding with the nadir of the δ13C excursion. Volcanic ash geochemistry and Hg isotope compositions suggest that mercury was mainly sourced from subduction‐related volcanic arc magmatism in the Tethys region, which peaked between 251.668 ± 0.079 and 251.589 ± 0.052 Ma. These results are compatible with suggestions that regional arc volcanism contributed to the causes of the PTBME in South China and provide evidence that Hg anomalies close to the PTB are not a reliable stratigraphic marker for the PTB extinction event. This study demonstrates that relations between volcanism, environmental perturbations and mass extinction during the Permian‐Triassic transition are better resolved with the aid of high‐precision U‐Pb zircon ages.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1525-2027
Relation: https://doaj.org/toc/1525-2027
DOI: 10.1029/2023GC010912
Access URL: https://doaj.org/article/336f4d1c3e1a478a95e2212153ad935a
Accession Number: edsdoj.336f4d1c3e1a478a95e2212153ad935a
Database: Directory of Open Access Journals
More Details
ISSN:15252027
DOI:10.1029/2023GC010912
Published in:Geochemistry, Geophysics, Geosystems
Language:English