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TitleIsotopic signatures of mercury contamination in Latest Permian oceans
AuthorGrasby, S E; Shen, W; Yin, R; Gleason, J E; Blum, J D; Lepak, R F; Hurley, J P; Beauchamp, B
SourceGeology vol. 45, no. 1, 2016 p. 55-58, https://doi.org/10.1130/G38487.1
Year2016
Alt SeriesEarth Sciences Sector, Contribution Series 20160079
PublisherGeological Society of America
Documentserial
Lang.English
Mediapaper; on-line; digital
File formatpdf
AreaSiberia; Russian Federation
Lat/Long WENS 50.0000 120.0000 75.0000 60.0000
Subjectsenvironmental geology; geochemistry; igneous and metamorphic petrology; mercury; mercury geochemistry; isotopes; isotope ratios; isotope geochemistry; marine organisms; marine sediments; marine ecology; marine environments; traps; Siberian Traps; Permian Extinction; Mercury concentrations; volcanic eruptions; large igneous provinces
Illustrationslocation maps; formulae; graphs; stratigraphic columns; schematic diagrams
ProgramWestern Arctic, High Arctic LIP, GEM2: Geo-mapping for Energy and Minerals
AbstractSedimentary records from the NW margin of Pangea and the Tethys show consistently anomalous high Hg levels at the Latest Permian extinction boundary. Hg stable isotope data through this interval show that background d202Hg values are consistent with normal marine conditions, but exhibit negative shifts coincident with increased Hg concentrations. Hg isotope mass independent fractionation (?199Hg) trends are consistent with increased volcanic input in deep-water marine environments. In contrast, near-shore environments have ?199Hg signatures are consistent with enhanced soil and/or biomass input. We hypothesize that the deep-water signature represents an overall global increase in volcanic Hg input and that this isotope signature is overwhelmed in near-shore locations due to Hg input from massive soil erosion and wildfire. This suggests that high productivity near shore regions of the world oceans may have experienced enhanced loading of Hg during the extinction event.
Summary(Plain Language Summary, not published)
Previous work by NRCan scientists was the first to recognise that major periods of volcanism in Earth history (Large Igneous Province - or LIP events)was associated with significant release of toxic mercury to the environment. While this can impact life it also serves as a time marker in the sedimentary record that allows global correlation of sedimentary rock. The current work in the Canadian Arctic employs the novel use of stable isotopes of mercury to understand how these toxic metals are globally distributed and incorporated into the environment. Specifically it demonstrates that major wildfires are an additional source of mercury during periods of major volcanic eruption.
GEOSCAN ID298841