Data/hora: 09/06/2024 13:49:31

Provedor de dados: | 5
País: | France
Título: | Methanogenesis and clay minerals diagenesis during the formation of dolomite nodules from the Tortonian marls of southern Spain
Autores: | Pierre, Catherine; Rouchy, Jean-marie; Blanc-valleron, Marie-madeleine; Etoubleau, Joel; Fouquet, Yves.
Data: | 2015-09
Ano: | 2015
Palavras-chave: | Authigenic dolomite nodules; Elemental geochemistry; Oxygen and carbon isotopes; Methanogenesis; Clay minerals diagenesis.
Resumo: | Dolomite nodules are widespread within the Tortonian marls of Fortuna and Lorca basins in southern Spain. They occur as large bodies of various forms (round, ovoid, tabular) that are parallel or secant relative to the stratification. They are massive and present sometimes internal conduits that are considered as drains used for the migration of fluids.  This study brings new results on the mineralogy and elemental and isotopic geochemistry of these dolomite nodules to better describe the processes that were occurring during their formation. The diagenetic reactions that have driven authigenic dolomite precipitation within the sediments involved on the one hand methanogenesis that produced 13C-poor CH4 and 13C-rich CO2, on the other hand carbonate and silicate weathering by the CO2-rich solutions, that released respectively alkalinity and cations in pore solutions. Moreover, the distribution of the major elements (Si, Al, K, Na, Ca, Mg, Fe) in the marls and dolomite nodules indicates that these elements were redistributed within the sedimentary formation during the diagenetic reactions without external inputs by the circulating fluids. These observations thus confirm the link between authigenic dolomite formation and clay minerals diagenesis in sediments where methanogenesis was active.
Tipo: | Text
Idioma: | Inglês

Identificador:

https://archimer.ifremer.fr/doc/00266/37752/35803.pdf

DOI:10.1016/j.marpetgeo.2015.04.017

https://archimer.ifremer.fr/doc/00266/37752/

Editor: | Elsevier Sci Ltd
Formato: | application/pdf
Fonte: | Marine And Petroleum Geology (0264-8172) (Elsevier Sci Ltd), 2015-09 , Vol. 66 , P. 606-615

Fonte:

2015 Elsevier Ltd. All rights reserved

info:eu-repo/semantics/openAccess

restricted use