气候变化领域集成服务门户(CCPortal): The microbially driven formation of siderite in salt marsh sediments

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DOI	10.1111/gbi.12371
	The microbially driven formation of siderite in salt marsh sediments
	Lin C.Y.; Turchyn A.V.; Krylov A.; Antler G.
发表日期	2020
ISSN	14724677
起始页码	207
结束页码	224
卷号	18 期号:2
英文摘要	We employ complementary field and laboratory-based incubation techniques to explore the geochemical environment where siderite concretions are actively forming and growing, including solid-phase analysis of the sediment, concretion, and associated pore fluid chemistry. These recently formed siderite concretions allow us to explore the geochemical processes that lead to the formation of this less common carbonate mineral. We conclude that there are two phases of siderite concretion growth within the sediment, as there are distinct changes in the carbon isotopic composition and mineralogy across the concretions. Incubated sediment samples allow us to explore the stability of siderite over a range of geochemical conditions. Our incubation results suggest that the formation of siderite can be very rapid (about two weeks or within 400 hr) when there is a substantial source of iron, either from microbial iron reduction or from steel material; however, a source of dissolved iron is not enough to induce siderite precipitation. We suggest that sufficient alkalinity is the limiting factor for siderite precipitation during microbial iron reduction while the lack of dissolved iron is the limiting factor for siderite formation if microbial sulfate reduction is the dominant microbial metabolism. We show that siderite can form via heated transformation (at temperature 100°C for 48 hr) of calcite and monohydrocalcite seeds in the presence of dissolved iron. Our transformation experiments suggest that the formation of siderite is promoted when carbonate seeds are present. 2019 The Authors. Geobiology published by John Wiley & Sons Ltd.
关键词	calcite carbonate concretion fluid composition isotopic composition limiting factor microbial community saltmarsh siderite steel structure sulfate-reducing bacterium transformation
语种	英语
来源机构	Geobiology
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/133196
推荐引用方式 GB/T 7714	Lin C.Y.,Turchyn A.V.,Krylov A.,et al. The microbially driven formation of siderite in salt marsh sediments[J]. Geobiology,2020,18(2).
APA	Lin C.Y.,Turchyn A.V.,Krylov A.,&Antler G..(2020).The microbially driven formation of siderite in salt marsh sediments.,18(2).
MLA	Lin C.Y.,et al."The microbially driven formation of siderite in salt marsh sediments".18.2(2020).