Journal article
Most Earth-surface calcites precipitate out of isotopic equilibrium
M Daëron, RN Drysdale, M Peral, D Huyghe, D Blamart, TB Coplen, F Lartaud, G Zanchetta
Nature Communications | NATURE PUBLISHING GROUP | Published : 2019
Abstract
Oxygen-isotope thermometry played a critical role in the rise of modern geochemistry and remains extensively used in (bio-)geoscience. Its theoretical foundations rest on the assumption that 18 O/ 16 O partitioning among water and carbonate minerals primarily reflects thermodynamic equilibrium. However, after decades of research, there is no consensus on the true equilibrium 18 O/ 16 O fractionation between calcite and water ( 18 α cc/w ). Here, we constrain the equilibrium relations linking temperature, 18 α cc/w , and clumped isotopes (Δ 47 ) based on the composition of extremely slow-growing calcites from Devils Hole and Laghetto Basso (Corchia Cave). Equilibrium 18 α cc/w values are syst..
View full abstractRelated Projects (2)
Grants
Awarded by Australian Research Council
Funding Acknowledgements
We thank C. Spotl and three anonymous reviewers for useful feedback on the manuscript. M.D. is grateful to T. Kluge for his early encouragement to write up this study. The clumped-isotope facility at LSCE is part of PANOPLY (Plateforme Analytique Geosciences Paris-Saclay) and was supported by the following institutions: Region Ile-de-France; Direction des Sciences de la Matiere du Commissariat a l'Energie Atomique; Institut National des Sciences de l'Univers, Centre National de la Recherche Scientifique; Universtite de Versailles/Saint-Quentin-en-Yvelines. M.D. thanks N. Smialkowski, F. Dewilde, and C. Waelbroeck (LSCE) for "bulk" delta<SUP>13</SUP>C<INF>VPDB</INF> and delta<SUP>18</SUP>O<INF>VPDB</INF> analyses on LGB and DVH. This work was partially supported by Australian Research Council Discovery Project Grants DP110102185 (to R.N.D., G.Z., and M.D.) and DP160102969 (to R.N.D. and G.Z.). R.N.D. was the grateful recipient of a 2017 Jean D'Alembert Fellowship awarded through the Universite Paris-Saclay and with support of LSCE. M.P. thanks the Commissariat a l'Energie Atomique for supporting her through "These Phare" PhD fellowship. M.D, D.H., and F.L. gratefully acknowledge the support of Agence Nationale de la Recherche project AMOR, led by Y. Donnadieu (CEREGE). The authors thank Yves-Marie Paulet and Laurent Chauvaud (LEMAR, UBO) for the collection of A. colbecki specimens, supported by the MACARBI project (IUEM). The authors are also grateful to the captain and crew of the RV Nereis II from the UMS Service at Sea of the OOB, for their help in acquiring N. cochlear shells, and to M. Sebilo (IEES, Sorbonne Universite) for oxygen-18 analyses of water from the Lacaze-Duthiers canyon. This is LSCE contribution #6534.