DOI: 10.1111/gbi.12130
Scopus记录号: 2-s2.0-84927074846
论文题名: Methanogenesis produces strong 13C enrichment in stromatolites of Lagoa Salgada, Brazil: A modern analogue for Palaeo-/Neoproterozoic stromatolites?
作者: Birgel D. ; Meister P. ; Lundberg R. ; Horath T.D. ; Bontognali T.R.R. ; Bahniuk A.M. ; de Rezende C.E. ; Vasconcelos C. ; Mckenzie J.A.
刊名: Geobiology
ISSN: 1472-4677
EISSN: 1472-4669
出版年: 2015
卷: 13, 期: 3 起始页码: 245
结束页码: 266
语种: 英语
Scopus关键词: carbon dioxide enrichment
; carbon isotope
; eukaryote
; lagoonal sedimentation
; methanogenesis
; micropaleontology
; photoautotrophy
; Proterozoic
; stromatolite
; sulfate-reducing bacterium
; Brazil
; Rio de Janeiro [Brazil]
; Salgada Lagoon
; Archaea
; carbon
; methane
; bacterium
; biogenesis
; biosynthesis
; Brazil
; chemistry
; geographic and geological phenomena
; metabolism
; microbiology
; sediment
; Bacteria
; Biogenesis
; Brazil
; Carbon
; Geologic Sediments
; Geological Processes
; Methane
Scopus学科分类: Earth and Planetary Sciences: General Earth and Planetary Sciences
; Environmental Science: General Environmental Science
; Agricultural and Biological Sciences: Ecology, Evolution, Behavior and Systematic
英文摘要: Holocene stromatolites characterized by unusually positive inorganic δ13CPDB values (i.e. up to +16‰) are present in Lagoa Salgada, a seasonally brackish to hypersaline lagoon near Rio de Janeiro (Brazil). Such positive values cannot be explained by phototrophic fixation of CO2 alone, and they suggest that methanogenesis was a dominating process during the growth of the stromatolites. Indeed, up to 5 mm methane was measured in the porewater. The archaeal membrane lipid archaeol showing δ13C values between -15 and 0‰ suggests that archaea are present and producing methane in the modern lagoon sediment. Moreover, 13C-depleted hopanoids diplopterol and 3β-methylated C32 17β(H),21β(H)-hopanoic acid (both -40‰) are preserved in lagoon sediments and are most likely derived from aerobic methanotrophic bacteria thriving in the methane-enriched water column. Loss of isotopically light methane through the water column would explain the residual 13C-enriched pool of dissolved inorganic carbon from where the carbonate constituting the stromatolites precipitated. The predominance of methanogenic archaea in the lagoon is most likely a result of sulphate limitation, suppressing the activity of sulphate-reducing bacteria under brackish conditions in a seasonally humid tropical environment. Indeed, sulphate-reduction activity is very low in the modern sediments. In absence of an efficient carbonate-inducing metabolic process, we propose that stromatolite formation in Lagoa Salgada was abiotically induced, while the 13C-enriched organic and inorganic carbon pools are due to methanogenesis. Unusually, 13C-enriched stromatolitic deposits also appear in the geological record of prolonged periods in the Palaeo- and Neoproterozoic. Lagoa Salgada represents a possible modern analogue to conditions that may have been widespread in the Proterozoic, at times when low sulphate concentrations in sea water allowed methanogens to prevail over sulphate-reducing bacteria. © 2015 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/85147
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作者单位: Department of Geodynamics and Sedimentology, University of Vienna, Vienna, Austria; Max Planck Institute for Marine Microbiology, Bremen, Germany; Geological Institute ETH, Zürich, Switzerland; Institute of Plant Biology, University of Zürich, Zürich, Switzerland; Department of Geology, University of Paraná (UFPR/LAMIR), Curitiba, Brazil; Universidade do Norte Fluminense, Laboratório de Ciências Ambientais, Centro de Biociências e Biotecnologia, Campos dos Goytacazes, Brazil; Department of Geodynamics and Sedimentology, University of Vienna, Althanstr. 14, Vienna, Austria
Recommended Citation:
Birgel D.,Meister P.,Lundberg R.,et al. Methanogenesis produces strong 13C enrichment in stromatolites of Lagoa Salgada, Brazil: A modern analogue for Palaeo-/Neoproterozoic stromatolites?[J]. Geobiology,2015-01-01,13(3)