Institut de minéralogie, de physique des matériaux et de cosmochimie |

Projet
ANR 11-JS56-001 CrIMin | ||||||||||||||||||||||||||

Crystal-chemistry
of iron-bearing minerals and implications in the geochemical cycling of
metal pollutants ## Project |

For decades, the isotopic composition of minerals is explored in order
to have access to the dynamics of a natural system or to make
paleoenvironmental reconstructions. The interpretation of isotopic
measurements done on natural samples is based on the knowledge of
isotopic fractionation factors when the components of the system of
interest (minerals, solutions) are in equilibrium. These equilibrium
constants are traditionally determined from a delicate experimental
approach. A theoretical alternative approach has been developed
recently. It is based on the calculation of vibrational properties by
molecular modeling and has been successfully applied to many minerals.
On the other hand, the accurate calculation of the isotopic properties
of an ion in solution is the technical barrier to overcome in order to
rigourously compare the theoretical and experimental data. Beyond the
methodological aspect, this project focused on the iron-bearing
minerals that play a key role in the fate of inorganic and organic
pollutants. | ||||||

Using this approach, molecular modeling provides a general theoretical framework for
interpreting the experimental data derived from the different
analytical techniques (e.g. diffraction techniques, vibrational
spectroscopies, X-ray absorption spectroscopies, isotopic analysis).
Beyond the results relevant to environmental mineralogy, the
substantial methodological work conducted in this project
(improvement of the modeling of mineral phases containing transition
elements and theoretical determination of the isotopic properties of
liquid solutions) could find a wide range of applications in Earth
Sciences, Material Sciences and Physics. |

Marc Blanchard
(PI) | IMPMC, mineralogy | Etienne Balan | IMPMC, mineralogy |

Guillaume Ferlat | IMPMC, physics | Michele Lazzeri | IMPMC, physics |

Carlos Pinilla (Post-doc) | IMPMC, physics | Lorenzo Paulatto | IMPMC, physics |

Ismaïla Dabo | ENPC, physics |

- Presentation of the proposal. ANR kick-off meeting, 13 dec. 2011, Paris
- Blanchard M.: Complementarity of computational molecular modelling and experimental techniques to study trace elements geochemistry. keynote presentation, Goldschmidt, Montreal, Canada, 24-29 June 2012.
- Pinilla C., Blanchard M., Ferlat G., Balan E., Vuilleumier R. & Mauri F.: Equilibrium isotope fractionation factors in liquids from path integral molecular dynamic simulations. Goldschmidt, Florence, Italie, 25-30 Aug. 2013
- Blanchard M., Pinilla C., Poitrasson F., Méheut M., Lazzeri M., Mauri F. & Balan E.: First-principles investigation of equilibrium iron isotope fractionation in oxide and sulfide minerals. invited presentation, Goldschmidt, Florence, Italie, 25-30 Aug. 2013
- Blanchard M., Balan E.: Theoretical investigation of vibrational and isotopic properties of iron (oxyhydr)oxides. Atelier Modélisation des Oxydes. GDR CNRS ModMat et Co-DFT, Paris, 16-17 sept. 2013.
- Blanchard M.: Theoretical investigation of isotopic fractionations: application to iron-bearing minerals. AGU Fall meeting, San Francisco, USA, 9-13 Dec. 2013
- Blanchard M., Balan E. Theoretical investigation of vibrational and isotopic properties of iron (oxyhydr)oxides. Atelier Modélisation des Oxydes. GDR CNRS ModMat et Co-DFT, 16-17 sept. 2013, Paris.
- Blanchard
M. Projet ANR CrIMin : Cristallochimie des minéraux ferrifères et
implications dans le cycle géochimique des polluants métalliques. Séminaire ANR sur les changements environnementaux, 19-20-21 mars 2014, Lille.

- Blanchard M., Morin G., Lazzeri M., Balan E., Dabo I. (2012) First-principles simulation of arsenate adsorption on the (1 -1 2) surface of hematite. Geochim. Cosmochim. Acta, 86, 182-195
- Blanchard M., Balan E., Giura P., Béneut K., Yi H., Morin G., Pinilla C., Lazzeri M., Floris A. (2013) Infrared spectroscopic properties of goethite: anharmonic broadening, long-range electrostatic effects and Al substitution. Phys. Chem. Minerals, 41, 289-302
- Balan E., Blanchard M., Pinilla C. & Lazzeri M. (2014) First-principles modeling of sulfate incorporation and
^{34}S/^{32}S isotopic fractionation in different calcium carbonates. Chemical Geology, 374-375, 84-91 - Pinilla C., Blanchard M., Balan E., Ferlat G., Vuilleumier R., Mauri F. (2014) Equilibrium fractionation of H and O isotopes in water from path integral molecular dynamics. Geochim. Cosmochim. Acta, 135, 203-216

This page was last modified, 15 Sept. 2014 | | |