US EPA

4964910 

Journal Article 

Isotopic signatures of mercury contamination in latest Permian oceans 

Grasby, SE; Shen, W; Yin, R; Gleason, JD; Blum, JD; Lepak, RF; Hurley, JP; Beauchamp, B 

2017 

Yes 

Geology
ISSN: 0091-7613 

45 

1 

55-58 

10.1130/G38487.1 

WOS:000396124000016 

Sedimentary records from the northwest margin of Pangea and the Tethys show anomalously high Hg levels at the latest Permian extinction boundary. Background delta Hg-202 values are consistent with normal marine conditions but exhibit negative shifts coincident with increased Hg concentrations. Hg isotope mass-independent fractionation (Delta Hg-199) trends are consistent with volcanic input in deep-water marine environments. In contrast, nearshore environments have Delta Hg-199 signatures 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 nearshore locations due to Hg from terrestrial sources. High-productivity nearshore regions may have experienced stressed marine ecosystems due to enhanced Hg loading.