文章基本信息

标题：The benthic foraminiferal δ34S records flux and timing of paleo methane emissions
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作者：C. Borrelli ; R. I. Gabitov ; M.-C. Liu 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2020
卷号：10
期号：1
页码：1-10
DOI：10.1038/s41598-020-58353-4
出版社：Springer Nature
摘要：In modern environments, pore water geochemistry and modelling simulations allow the study of methane (CH 4 ) sources and sinks at any geographic location. However, reconstructing CH 4 dynamics in geological records is challenging. Here, we show that the benthic foraminiferal δ 34 S can be used to reconstruct the flux (i.e., diffusive vs. advective) and timing of CH 4 emissions in fossil records. We measured the δ 34 S of Cassidulina neoteretis specimens from selected samples collected at Vestnesa Ridge, a methane cold seep site in the Arctic Ocean. Our results show lower benthic foraminiferal δ 34 S values (∼20‰) in the sample characterized by seawater conditions, whereas higher values (∼25-27‰) were measured in deeper samples as a consequence of the presence of past sulphate-methane transition zones. The correlation between δ 34 S and the bulk benthic foraminiferal δ 13 C supports this interpretation, whereas the foraminiferal δ 18 O-δ 34 S correlation indicates CH 4 advection at the studied site during the Early Holocene and the Younger-Dryas - post-Bølling. This study highlights the potential of the benthic foraminiferal δ 34 S as a novel tool to reconstruct the flux of CH 4 emissions in geological records and to indirectly date fossil seeps.