GEOSCAN Search Results: Fastlink


TitleMercury anomalies across the end Permian mass extinction in south China from shallow and deep water depositional environments
AuthorWang, X; Cawood, P A; Zhao, H; Zhao, L; Grasby, S E; Chen, Z -Q; Wignall, P B; Lv, Z; Han, C
SourceEarth and Planetary Science Letters vol. 496, 2018 p. 159-167, (Open Access)
Alt SeriesNatural Resources Canada, Contribution Series 20180118
PublisherElsevier BV
Mediapaper; on-line; digital
File formatpdf; html; xlsx
Lat/Long WENS 99.0000 123.0000 33.0000 21.0000
Subjectsstratigraphy; geochemistry; tectonics; environmental geology; paleontology; extinctions, biotic; geochemical anomalies; mercury geochemistry; stable isotope studies; concentration; depositional environment; marine environments; continental margins; nearshore environment; tectonic history; magmatism; bedrock geology; lithology; igneous rocks; volcanic rocks; basalts; volcanic ash; sedimentary rocks; limestones; mudstones; marls; shales; organic carbon; atmospheric geochemistry; source areas; paleogeography; biostratigraphy; micropaleontology; microfossils; conodonts; end-Permian mass extinction; Permian-Triassic boundary; Siberian Traps Large Igneous Province; South China Craton; Yinkeng Formation; Changxing Formation; Daye Formation; Dalong Formation; Feixianguan Formation; mass extinctions; total organic carbon; water depths; species richness; large igneous provinces; Phanerozoic; Mesozoic; Triassic; Paleozoic; Permian
Illustrationsgeoscientific sketch maps; lithologic sections; geochemical profiles; biostratigraphic charts
ProgramGEM2: Geo-mapping for Energy and Minerals, Western Arctic Sverdrup Basin
ProgramIGCP Project 630 - Permian-Triassic Climatic and Environmental Extremes and Biotic Response
Released2018 06 06
AbstractLife on Earth suffered its greatest bio-crisis since multicellular organisms rose 600 million years ago during the end-Permian mass extinction. Coincidence of the mass extinction with flood basalt eruptions in Siberia is well established, but the exact causal connection between the eruptions and extinction processes in South China is uncertain due to their wide spatial separation and the absence of direct geochemical evidence linking the two. The concentration and stable isotope analysis of mercury provides a way to test these links as its concentration is thought to be tied to igneous activity. Mercury/total organic carbon ratios from three Permian-Triassic boundary sections with a well-resolved extinction record in South China show elevated values (up to 900 ppb/wt.% relative to a background of <100ppb/wt.%) that exactly coincides with the end-Permian mass extinction horizon. This enrichment does not show any correlation with redox and sedimentation rate variations during that time. Hg isotope mass-independent fractionation (delta-199Hg), with sustained positive values, indicate a predominant atmospheric-derived signature of volcanic Hg in deep-shelf settings of the Daxiakou and Shangsi sections. In contrast, the nearshore environment of the Meishan section displays a negative delta-199Hg signature, interpreted to be related to terrestrial Hg sources. Such temporal differences in delta-199Hg values shed new light on Hg geochemical behavior in marine settings, and also on the kill mechanisms associated with volcanism that were responsible for biotic mortality at the end of the Permian.
Summary(Plain Language Summary, not published)
GEM research focused on new methods to aid circum-arctic correlation of rock units led to the discovery that there are anomalous enrichments of the metal mercury in sediments deposited at the Permian Extinction boundary. This was the largest extinction in Earth History and is thought to be related to a massive volcanic eruption at that time that in many ways had similar impacts as modern anthropogenic activity on the global climate and environment. Mercury is considered a tracer of that eruption. Work has been extended with research partners in China to see if the same enrichment in mercury is observed on a global scale. These findings support that, and indicate there was global impact of volcanism that likely directly impacted ecosystems and environments at that time.