DOI: 10.1038/s41561-019-0509-1
论文题名: Iron-oxidizer hotspots formed by intermittent oxic–anoxic fluid mixing in fractured rocks
作者: Bochet O. ; Bethencourt L. ; Dufresne A. ; Farasin J. ; Pédrot M. ; Labasque T. ; Chatton E. ; Lavenant N. ; Petton C. ; Abbott B.W. ; Aquilina L. ; Le Borgne T.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2020
卷: 13, 期: 2 起始页码: 149
结束页码: 155
语种: 英语
英文关键词: aquifer
; bacterium
; biogeochemical cycle
; borehole
; fluid flow
; fracture zone
; iron oxide
; microbial community
; spatial distribution
; water table
; France
; Bacteria (microorganisms)
英文摘要: Subsurface environments host most of the fresh water on Earth as well as diverse microorganisms that may constitute a significant part of the biosphere. However, the dynamics and spatial distribution of subsurface microorganisms and their response to hydrological processes are poorly understood. Here we used chemical and metagenomic analyses of groundwater in a fractured rock aquifer in western France to determine the role of fractures in the formation of deep microbial hotspots in the subsurface. The majority of fractures, sampled in a 130-m-deep borehole, were anoxic, but a fracture carrying oxic groundwater was detected at 54-m depth, associated with a fivefold increase in the abundance of iron-oxidizing bacteria. We developed a mechanistic model of fluid flow and mixing in fractures and found that such microbial hotspots are sustained by the mixing of fluids with contrasting redox chemistries at intersections of fractures. The model predicts that metre-scale changes in near-surface water table levels cause intermittent oxygen delivery through deep fractures, which can extend the depth of the habitable zone for iron-oxidizing bacteria hundreds of metres into the subsurface. Given that fractures are ubiquitous at multiple scales in the subsurface, such deep microbial hotspots may substantially influence microbial communities and their effect on Earth’s biogeochemical cycles. © 2020, The Author(s), under exclusive licence to Springer Nature Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/169559
Appears in Collections: 气候变化与战略
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作者单位: University of Rennes, CNRS, Géosciences Rennes, UMR 6118, Rennes, France; University of Rennes, CNRS, Ecobio, UMR 6553, Rennes, France; Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT, United States
Recommended Citation:
Bochet O.,Bethencourt L.,Dufresne A.,et al. Iron-oxidizer hotspots formed by intermittent oxic–anoxic fluid mixing in fractured rocks[J]. Nature Geoscience,2020-01-01,13(2)