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Mechanism of leached layer formation during chemical weathering of silicate minerals

2012; Geological Society of America; Volume: 40; Issue: 10 Linguagem: Inglês

10.1130/g33339.1

1943-2682

Encarnación Ruíz-Agudo, Christine V. Putnis, Carlos Rodríguez‐Navarro, Andrew Putnis,

Mine drainage and remediation techniques

Research Article| October 01, 2012 Mechanism of leached layer formation during chemical weathering of silicate minerals Encarnación Ruiz-Agudo; Encarnación Ruiz-Agudo 1Institut für Mineralogie, University of Münster, Corrensstrasse 24, 48149, Münster, Germany2Department of Mineralogy and Petrology, University of Granada, Fuentenueva s/n, 18071 Granada, Spain Search for other works by this author on: GSW Google Scholar Christine V. Putnis; Christine V. Putnis 1Institut für Mineralogie, University of Münster, Corrensstrasse 24, 48149, Münster, Germany Search for other works by this author on: GSW Google Scholar Carlos Rodriguez-Navarro; Carlos Rodriguez-Navarro 2Department of Mineralogy and Petrology, University of Granada, Fuentenueva s/n, 18071 Granada, Spain Search for other works by this author on: GSW Google Scholar Andrew Putnis Andrew Putnis 1Institut für Mineralogie, University of Münster, Corrensstrasse 24, 48149, Münster, Germany Search for other works by this author on: GSW Google Scholar Author and Article Information Encarnación Ruiz-Agudo 1Institut für Mineralogie, University of Münster, Corrensstrasse 24, 48149, Münster, Germany2Department of Mineralogy and Petrology, University of Granada, Fuentenueva s/n, 18071 Granada, Spain Christine V. Putnis 1Institut für Mineralogie, University of Münster, Corrensstrasse 24, 48149, Münster, Germany Carlos Rodriguez-Navarro 2Department of Mineralogy and Petrology, University of Granada, Fuentenueva s/n, 18071 Granada, Spain Andrew Putnis 1Institut für Mineralogie, University of Münster, Corrensstrasse 24, 48149, Münster, Germany Publisher: Geological Society of America Received: 21 Feb 2012 Revision Received: 24 Apr 2012 Accepted: 25 Apr 2012 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2012 Geological Society of America Geology (2012) 40 (10): 947–950. https://doi.org/10.1130/G33339.1 Article history Received: 21 Feb 2012 Revision Received: 24 Apr 2012 Accepted: 25 Apr 2012 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Encarnación Ruiz-Agudo, Christine V. Putnis, Carlos Rodriguez-Navarro, Andrew Putnis; Mechanism of leached layer formation during chemical weathering of silicate minerals. Geology 2012;; 40 (10): 947–950. doi: https://doi.org/10.1130/G33339.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The dissolution of most common multicomponent silicate minerals and glasses is typically incongruent, as shown by the nonstoichiometric release of the solid phase components. This results in the formation of so-called surface leached layers. Due to the important effects these leached layers may have on mineral dissolution rates and secondary mineral formation, they have attracted a great deal of research. However, the mechanism of leached layer formation is a matter of vigorous debate. Here we report on an in situ atomic force microscopy (AFM) study of the dissolution of wollastonite, CaSiO3, as an example of leached layer formation during dissolution. Our in situ AFM results provide, for the first time, clear direct experimental evidence that leached layers are formed in a tight interface-coupled two-step process: stoichiometric dissolution of the pristine mineral surfaces and subsequent precipitation of a secondary phase (most likely amorphous silica) from a supersaturated boundary layer of fluid in contact with the mineral surface. This occurs despite the fact that the bulk solution is undersaturated with respect to the secondary phase. Our results differ significantly from the concept of preferential leaching of cations, as postulated by most currently accepted incongruent dissolution models. This interface-coupled dissolution-precipitation model has important implications in understanding and evaluating dissolution kinetics of major rock-forming minerals. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.