High mercury enrichments in sediments from the Baltic continent across the late Cambrian: Controls and implications
High mercury enrichments in sediments from the Baltic continent across the late Cambrian: Controls and implications
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DOI：
10.1016/j.chemgeo.2022.120846
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发表时间：
2022-04
期刊：
影响因子：
3.9
通讯作者：
L. Bian;A. Chappaz;N. Schovsbo;A. T. Nielsen;H. Sanei
中科院分区：
文献类型：
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作者：
L. Bian;A. Chappaz;N. Schovsbo;A. T. Nielsen;H. Sanei
晚寒武世见证了重大的生物和环境变化。然而，造成这一巨大更替的主要原因在很大程度上仍然不明。本研究调查汞（Hg）富集从苗岭纪晚期芙蓉节在一个独特的明矾页岩钻芯从瑞典东南部。研究结果表明，由于存在还原条件和水体持续供汞，汞的背景值相对较高。然而，我们最引人注目的发现是四个汞异常的存在。最明显的汞异常的特征是总汞（~900 ppb）和汞/有机碳比值（~80）的高值，以及我们认为来自火山的汞的特定的质量独立分馏特征（MIFs; Δ 199 Hg，Δ 201 Hg和Δ 200 Hg）。这次汞负载事件发生在全球公认的斯特普托亚正碳同位素漂移（SPICE）事件之后，可能归因于该期间的火山活动。
The late Cambrian witnessed significant biological and environmental changes. However, the main triggers responsible for that formidable turnover remain largely unknown. This study investigates mercury (Hg) enrichments from the late Miaolingian to Furongian section in a unique Alum Shale drilled core obtained from southeast Sweden. Our results show that the background level of Hg is relatively high because of the presence of reducing conditions and continuous Hg supply from water mass. However, our most spectacular findings are the presence of four Hg anomalies. The most pronounced Hg anomalies are characterized by the high values in total Hg (~900 ppb) and Hg/TOC ratio (~80), as well as specific signatures of mass independent fractionation of Hg (MIFs; Δ199Hg, Δ201Hg, and Δ200Hg) that we attribute to volcanic-derived Hg. This Hg loading event occurred immediately after the globally recognized Steptoean Positive Carbon Isotope Excursion (SPICE) event and could be attributed to volcanic activities during that period.