文章基本信息

标题：Discovery and biogeochemistry of asphalt seeps in the North São Paulo Plateau, Brazilian Margin
本地全文：下载
作者：Kai Jiang ; Jing Zhang ; Akihiro Sakatoku 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2018
卷号：8
期号：1
页码：12619
DOI：10.1038/s41598-018-30928-2
语种：English
出版社：Springer Nature
摘要：An initial multiple biogeochemical dataset was acquired from the first discovered asphalt seeps in the Brazil margin during deep-sea dive surveys in 2013 using a manned submersible. These surveys were conducted on the outer escarpment of the North São Paulo Plateau. Sediment cores taken from the submersible were processed for pore water and sediment biogeochemistry. The silica concentration, as a chemical geothermometer, showed a steep gradient in the pore water, which indicates the possibility of an active brine system operating in the seepage area. Rare earth elements were used as powerful tracers of chemical processes. Low rare earth element concentrations in both asphalt and Fe-Mn oxyhydroxide-phase sediments suggests that rare earth elements were released during the oil fractionation and biodegradation processes and further depleted under the reducing environment. The main bacterial communities of the sediment were Proteobacteria in the asphalt sites, while at non-asphalt sites, the main bacterial communities of sediment were Firmicutes. Stable carbon and nitrogen isotopes were used to determine the food sources of the heterotrophs, and results suggest that asphalt probably provides a carbon source for these benthic animals. This study may provide useful information to clarify the impact of heavy hydrocarbon seepage on the marine ecosystem.