干旱区生态环境知识资源中心(Arid): Sedimentary exhalative venting of bioavailable nitrogen into the early ocean

Arid

DOI	10.1016/j.epsl.2021.116963
	Sedimentary exhalative venting of bioavailable nitrogen into the early ocean
	Stueken, Eva E.; Gregory, Daniel D.; Mukherjee, Indrani; McGoldrick, Peter
通讯作者	Stueken, EE (corresponding author), Univ St Andrews, Sch Earth & Environm Sci, North St,Irvine Bldg, St Andrews KY16 9AL, Fife, Scotland.
来源期刊	EARTH AND PLANETARY SCIENCE LETTERS
ISSN	0012-821X
EISSN	1385-013X
出版年	2021
卷号	565
英文摘要	Ore deposits found in Proterozoic marine sedimentary basins supply much of the world's zinc. Many of the deposits formed contemporaneously with their host sediments when saline brines circulating from deeper in the basin reached the sea floor. Textural, geochemical and isotopic features of these SEDEX ('sedimentary-exhalative') deposits and their host sediments indicate that biologically active seeps, vents and brine pools were a feature of many ore-forming systems. In mineralised pockets of midProterozoic basins, these 'microbial oases' were productive areas in an otherwise low productivity, anoxic, deep marine realm. Here we hypothesize that these metal-rich brines which circulated through organic matter-rich substrate also carried high levels of fixed nitrogen and stimulated distinct ecosystems at sites of mineralisation, or enhanced productivity more broadly in the basin. We tested this hypothesis with organic carbon and nitrogen analyses of samples of carbonaceous siltstone and shale from the 1.64 Ga Barney Creek Formation of northern Australia. The Barney Creek Formation hosts several SEDEX Zn systems, including one of the world's largest deposits at McArthur River Mine (the HYC deposit). Samples come from the mineralised edge of HYC and from correlated strata in drill cores at varying distances (1-60 km) from the deposit. The data reveal lower ratios of total organic carbon (TOC) to total nitrogen (TN) closer to the ore body. Strong correlations (r(2) > 0.7) between TOC and TN and the absence of excess N in the samples suggest that most N was buried as bound to organic matter. Bioavailable N was thus probably more abundant closer to HYC, consistent with fixed nitrogen input by hydrothermal fluids. If correct, our data may suggest that such a hydrothermal nitrogen point source enabled microbes to develop lower C:N ratios in their biomass. A hydrothermal nitrogen source is also supported by a gradient in delta N-15 values from = +4 parts per thousand proximal to the vent to +7.5 parts per thousand in distal sites, which may point towards recycling of ammonium from the underlying Wollogorang Formation (1.73 Ga). This unit has previously been identified as a source of over-mature hydrocarbons to the ore-forming fluid. We speculate that, during the mid-Proterozoic, fixed nitrogen carried by SEDEX hydrothermal brines may have locally offset the lack of aerobic nutrient remineralization that characterized most of the anoxic Precambrian deep ocean and thus stimulated biological productivity in areas where the brines reached the sea floor, and, possibly, more broadly as spent brines mixed into the water column. (C) 2021 Elsevier B.V. All rights reserved.
英文关键词	Proterozoic life nitrogen cycling SEDEX deposits
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000649176900015
WOS关键词	MCARTHUR BASIN ; NORTHERN-TERRITORY ; PB/ZN/AG DEPOSIT ; ORGANIC NITROGEN ; SULFUR ISOTOPES ; STABLE CARBON ; EVOLUTION ; RIVER ; GEOCHEMISTRY ; AUSTRALIA
WOS类目	Geochemistry & Geophysics
WOS研究方向	Geochemistry & Geophysics
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/349955
作者单位	[Stueken, Eva E.] Univ St Andrews, Sch Earth & Environm Sci, North St,Irvine Bldg, St Andrews KY16 9AL, Fife, Scotland; [Gregory, Daniel D.] Earth Sci Ctr, Dept Earth Sci, 22 Russell St, Toronto, ON M5S 3B1, Canada; [Mukherjee, Indrani; McGoldrick, Peter] Univ Tasmania, CODES, Hobart, Tas 7001, Australia; [Mukherjee, Indrani; McGoldrick, Peter] Univ Tasmania, IMAS, Hobart, Tas 7001, Australia
推荐引用方式 GB/T 7714	Stueken, Eva E.,Gregory, Daniel D.,Mukherjee, Indrani,et al. Sedimentary exhalative venting of bioavailable nitrogen into the early ocean[J],2021,565.
APA	Stueken, Eva E.,Gregory, Daniel D.,Mukherjee, Indrani,&McGoldrick, Peter.(2021).Sedimentary exhalative venting of bioavailable nitrogen into the early ocean.EARTH AND PLANETARY SCIENCE LETTERS,565.
MLA	Stueken, Eva E.,et al."Sedimentary exhalative venting of bioavailable nitrogen into the early ocean".EARTH AND PLANETARY SCIENCE LETTERS 565(2021).