title: Mg/Ca partitioning between aqueous solution and aragonite mineral: a molecular dynamics study.
abstract: We have calculated the concentrations of Mg in the bulk and surfaces of aragonite CaCO(3) in equilibrium with aqueous solution, based on molecular dynamics simulations and grand-canonical statistical mechanics. Mg is incorporated in the surfaces, in particular in the (001) terraces, rather than in the bulk of aragonite particles. However, the total Mg content in the bulk and surface of aragonite particles was found to be too small to account for the measured Mg/Ca ratios in corals. We therefore argue that most Mg in corals is either highly metastable in the aragonite lattice, or is located outside the aragonite phase of the coral skeleton, and we discuss the implications of this finding for Mg/Ca paleothermometry.
authors: Department of Chemistry, University College London, 20 Gordon St. London WC1H 0AJ, United Kingdom.
authors: Sergio E
authors: SE
authors: Ruiz-Hernandez
authors: Ricardo
authors: R
authors: Grau-Crespo
authors: Neyvis
authors: N
authors: Almora-Barrios
authors: Mariëtte
authors: M
authors: Wolthers
authors: A Rabdel
authors: AR
authors: Ruiz-Salvador
authors: Nestor
authors: N
authors: Fernandez
authors: Nora H
authors: NH
authors: de Leeuw
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry*; D003460:Crystallization; D008274:Magnesium / Q000737:chemistry*; D008903:Minerals / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D012996:Solutions / Q000737:chemistry*
chemical_list: D008903:Minerals; D012996:Solutions; D002119:Calcium Carbonate; D008274:Magnesium; D002118:Calcium