GEOSCAN Search Results: Fastlink


TitleGlobal mercury cycle during the end-Permian mass extinction and subsequent Early Triassic recovery
AuthorWang, X; Cawood, P A; Zhao, H; Zhao, L; Grasby, S E; Chen, Z -Q; Zhang, L
SourceEarth and Planetary Science Letters vol. 513, 2019 p. 144-155,
Alt SeriesNatural Resources Canada, Contribution Series 20180426
PublisherElsevier BV
Mediapaper; on-line; digital
File formatpdf; html; xlsx
AreaKashmir; Srinagar; India
Lat/Long WENS 74.9167 75.9167 34.1000 33.9500
Subjectsstratigraphy; geochemistry; tectonics; environmental geology; paleontology; Lower Triassic; Upper Permian; extinctions, biotic; geochemical anomalies; mercury geochemistry; stable isotope studies; concentration; carbon isotopes; depositional environment; marine environments; weathering; continental margins; tectonic history; magmatism; volcanism; bedrock geology; lithology; sedimentary rocks; limestones; mudstones; shales; organic carbon; atmospheric geochemistry; source areas; paleogeography; biostratigraphy; micropaleontology; microfossils; conodonts; fossil zones; clay minerals; major element analyses; trace element analyses; aluminum geochemistry; molybdenum geochemistry; geochemical anomalies; end-Permian mass extinction; Permian-Triassic boundary; Siberian Traps Large Igneous Province; Isarcicella Isarcica; Ammonoids; Tethys Sea; Panthallassa Ocean; Gondwana; Sverdup Basin; mass extinctions; large igneous provinces; chemostratigraphy; total organic carbon; ocean redox conditions; sea surface temperatures; Phanerozoic; Mesozoic; Triassic; Paleozoic; Permian
Illustrationsgeoscientific sketch maps; location maps; lithologic sections; geochemical profiles; geochemical plots; profiles
ProgramGEM2: Geo-mapping for Energy and Minerals, Western Arctic, High Arctic LIP
Released2019 03 04
AbstractThe end-Permian mass extinction (EPME) at ~252Ma was the most severe extinction in the Phanerozoic. Marine ecosystems devastated by the EPME had a highly prolonged recovery, and did not substantially recover until after the Smithian-Spathian substage boundary (SSB) of the Lower Triassic (5 to 9Ma after the EPME). While the Siberian Traps large igneous province (STLIP) has been invoked as the driver of the mass extinction, there remains controversy as to the cause of the protracted Early Triassic recovery; although renewed STLIP volcanism has been suggested. These previous studies though have drawn conclusions based on geochemical records of sediments deposited in northern latitude settings. To investigate the relationship between STLIP and extinction/recovery processes on a global base, we examined mercury chemostratigraphy, including mercury concentrations and isotopes, from high southern latitude and equatorial sections that span the Late Permian Changhsingian to Early Triassic Spathian substage successions; the Guryul Ravine section, Kashmir in northern India, and the Chaohu section in southern China. Organic and inorganic carbon-isotope data define the EPME horizon in the Chaohu section and the SSB in the Guryul Ravine section, respectively. Hg/TOC values are dramatically elevated approaching the EPME horizon and maintain high values until the lower Isarcicella Isarcica conodont zone, the base of which is believed to be the end of the mass extinction. In the stratigraphically overlying beds, Hg/TOC generally displays lower values with slight fluctuations through the two sections. These fluctuations are likely related to the increased terrestrial Hg influx associated with strong chemical weathering in the Early Triassic, as shown by a positive correlation between the contents of Hg and Al, and by less positive delta-199Hg values in Early Triassic samples. Our data, presenting the first Southern Hemisphere Hg record from Guryul Ravine, in combination with previous results, indicates that anomalous high mercury deposition at the EPME occurred globally. The generally positive delta-199Hg values at this time reflects atmospheric-derived Hg, consistent with a volcanic Hg source which we suggest indicates global impact of STLIP eruption. In contrast, there is no evidence for a global Hg/TOC anomaly during the protracted Early Triassic biotic recovery, suggesting that potentially renewed STLIP volcanism had only a northern hemisphere influence on the global Hg cycle. This more limited impact, may still have played a role in the delayed Early Triassic recovery.
Summary(Plain Language Summary, not published)
A serendipitous outcome of GEM work was recognition that mercury in the sedimentary record can be used as a tracer of large igneous eruption in Earth history, allowing a direct linkage to be made between the eruption and ecological stressed caused to the planet by volcanic emissions. This provides insight to past environmental crises on Earth and an analogue for current anthropogenic impacts. This study provides the first global view of the impact of volcanism associated with the largest eruption in Earth history as well as the largest known mass extinction that it caused.