1. Zirconium and hafnium fractionation and distribution of Rare Earth Elements in neutral–alkaline waters: Case study of Lake Van hydrothermal system, Turkey
- Author
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M. Venturi, G. Ozek, Paolo Censi, Ahmet Sasmaz, Pierpaolo Zuddas, Marianna Cangemi, Daniela Piazzese, Firat University, Institut des Sciences de la Terre de Paris (iSTeP), Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut national des sciences de l'Univers (INSU - CNRS), Università degli studi di Palermo - University of Palermo, Sasmaz A., Zuddas P., Cangemi M., Piazzese D., Ozek G., Venturi M., and Censi P.
- Subjects
Calcite ,Zirconium ,Aqueous solution ,Turkey ,Chemistry ,Inorganic chemistry ,Carbonate minerals ,chemistry.chemical_element ,Alkaline lakes, REE, Turkey, Zr/Hf ratio ,Authigenic ,Fractionation ,010501 environmental sciences ,010502 geochemistry & geophysics ,REE ,Alkaline lakes ,01 natural sciences ,6. Clean water ,Hydrothermal circulation ,chemistry.chemical_compound ,Adsorption ,[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry ,Geochemistry and Petrology ,Zr/Hf ratio ,Economic Geology ,0105 earth and related environmental sciences - Abstract
International audience; We investigated the distribution of Zr, Hf, and rare earth elements (REE) as the sum of lanthanides plus Y in the hydrothermal system in the Lake Van area of south-eastern Turkey. This system is characterised by water with variable pH in alkaline conditions resulting from hydrothermal CO2 upraise and neoformation of calcite minerals in near equilibrium with the interacting waters. Zr, Hf, and REE determinations were carried out for aqueous phases and suspended solids in lake water and surrounding thermal springs. We found that dissolved Hf is partitioned relative to Zr during calcite formation and that such fractionation is a function of the Ca2+ activity in warm water. The observed Zrsingle bondHf fractionation is explained by coulombic interactions that occur between suspended solid particles and dissolved phases at the calcite-water interface. There, the surfaces of carbonate minerals demonstrated greater reactivity towards aqueous Hf-bearing species relative to Zr-complexes. This evidence involves a coulombic mechanism of reactivity at the calcite-water interface because Hf complexes are negatively charged while Zr compounds are uncharged. Thus, authigenic calcite can behave as a suitable host for dissolved metal ion species to adsorb on crystal surfaces to remediate waste waters from mine drainage.
- Published
- 2021