Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1073/pnas.1721733115 |
Mercury isotope signatures record photic zone euxinia in the Mesoproterozoic ocean | |
Wang Zheng; Geoffrey J. Gilleaudeau; Linda C. Kah; and Ariel D. Anbar | |
2018-10-01 | |
发表期刊 | PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA |
出版年 | 2018 |
卷号 | 115期号:42页码:10594-10599 |
英文摘要 | AbstractPhotic zone euxinia (PZE) is a condition where anoxic, H2S-rich waters occur in the photic zone (PZ). PZE has been invoked as an impediment to the evolution of complex life on early Earth and as a kill mechanism for Phanerozoic mass extinctions. Here, we investigate the potential application of mercury (Hg) stable isotopes in marine sedimentary rocks as a proxy for PZE by measuring Hg isotope compositions in late Mesoproterozoic (∼1.1 Ga) shales that have independent evidence of PZE during discrete intervals. Strikingly, a significantly negative shift of Hg mass-independent isotope fractionation (MIF) was observed during euxinic intervals, suggesting changes in Hg sources or transformations in oceans coincident with the development of PZE. We propose that the negative shift of Hg MIF was most likely caused by (i) photoreduction of Hg(II) complexed by reduced sulfur ligands in a sulfide-rich PZ, and (ii) enhanced sequestration of atmospheric Hg(0) to the sediments by thiols and sulfide that were enriched in the surface ocean as a result of PZE. This study thus demonstrates that Hg isotope compositions in ancient marine sedimentary rocks can be a promising proxy for PZE and therefore may provide valuable insights into changes in ocean chemistry and its impact on the evolution of life. |
英文关键词 | photic zone euxinia mercury stable isotopes Mesoproterozoic mass-independent fractionation |
领域 | 地球科学 ; 气候变化 ; 资源环境 |
URL | 查看原文 |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/204996 |
专题 | 地球科学 资源环境科学 气候变化 |
推荐引用方式 GB/T 7714 | Wang Zheng,Geoffrey J. Gilleaudeau,Linda C. Kah,et al. Mercury isotope signatures record photic zone euxinia in the Mesoproterozoic ocean[J]. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA,2018,115(42):10594-10599. |
APA | Wang Zheng,Geoffrey J. Gilleaudeau,Linda C. Kah,&and Ariel D. Anbar.(2018).Mercury isotope signatures record photic zone euxinia in the Mesoproterozoic ocean.PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA,115(42),10594-10599. |
MLA | Wang Zheng,et al."Mercury isotope signatures record photic zone euxinia in the Mesoproterozoic ocean".PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 115.42(2018):10594-10599. |
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