Distribution et contrôle cristallographique des éléments Ge, Ga et Cd dans les sphalérites des gisements de type Mississippi Valley dans les districts de Central et East Tennessee, USA

Abstract : Mississippi Valley-type Type deposits (MVT) in central and eastern Tennessee, respectively MTM (Middle Tennessee Mine) and ETM (East Tennessee Mine), contain large reserves of zinc in the form of sphalerite, but also germanium in substitution of zinc in sphalerite. However, only the deposits District MTM contain economic concentrations of germanium. These two mining districts hosted in the same geological formations and with a comparable mineralogy, are compared in order to understand the distribution of germanium and other trace elements in MVT. Analyses at atomic scale by atomic absorption spectroscopy X, XANES and EXAFS, revealed several of germanium configurations in sphalerites: germanium can substituted to zinc in ZnS under 2 + and 4+ form, but it can be under the form of nanoscale inclusions of germanium oxide associated with sphalerite. Analyses at mineral scale by electron microprobe, LA-ICP-MS and Raman spectroscopy showed two groups of trace elements: i) the first group composed by Fe and Cd is preferentially incorporated following (110) faces of sphalerite, ii) the second group composed by Cu, Ga and Ge, is preferably incorporated following (010) faces of sphalerite. The coupling of Raman spectroscopy with laser ablation ICP-MS revealed a partitioning of trace elements between the cubic and hexagonal forms of ZnS: the elements Cd and Fe are more concentrated in the cubic form, while Cu, Ga and Ge are more concentrated in the hexagonal ZnS
Document type :
Theses
Complete list of metadatas

Cited literature [177 references]  Display  Hide  Download

https://hal.univ-lorraine.fr/tel-01751395
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 1:18:28 PM
Last modification on : Friday, April 5, 2019 - 8:21:42 PM

File

DDOC_T_2014_0298_BONNET.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01751395, version 1

Citation

Julien Bonnet. Distribution et contrôle cristallographique des éléments Ge, Ga et Cd dans les sphalérites des gisements de type Mississippi Valley dans les districts de Central et East Tennessee, USA. Sciences de la Terre. Université de Lorraine, 2014. Français. ⟨NNT : 2014LORR0298⟩. ⟨tel-01751395⟩

Share

Metrics

Record views

30

Files downloads

42