Role of fluid mixing in deep dissolution of carbonates
Corbella i Cordomí, Mercè (Universitat Autònoma de Barcelona. Departament de Geologia)
Ayora, Carles (Consejo Superior de Investigaciones Científicas (Espanya). Institut de Ciències de la Terra Jaume Almera)

Date:	2003
Abstract:	The presence of cavities filled with new minerals in carbonate rocks is a common feature in oil reservoirs and lead-zinc deposits. Since groundwater equilibrates rapidly with carbonates, the presence of dissolution cavities in deep carbonate host rocks is a paradox. Two alternative geochemical processes have been proposed to dissolve carbonates at depth: hydrogen sulfide oxidation to sulfuric acid, and metal sulfide precipitation. With the aid of geochemical modeling we show that mixing two warm solutions saturated with carbonate results in a new solution that dissolves limestone. Variations in the proportion of the end-member fluids can also form a supersaturated mixture and fill the cavity with a new generation of carbonate. Mixing is in general more effective in dissolving carbonates than the aforementioned processes. Moreover, mixing is consistent with the wide set of textures and mineral proportions observed in cavity infillings.
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan aquestes es distribueixin sota la mateixa llicència que regula l'obra original i es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Hydrothermal karst ; MVT deposits ; Reactive transport ; Fluid mixing ; Carbonate dissolution
Published in:	Geologica acta, Vol. 1, Núm. 4 (2003) , p. 305-313, ISSN 1696-5728

Adreça alternativa: https://raco.cat/index.php/GeologicaActa/article/view/82178
Adreça alternativa: https://revistes.ub.edu/index.php/GEOACTA/article/view/1823
DOI: 10.1344/105.000001618

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