Godel Bélinda, Maier Wolfgang Derek et Barnes Sarah-Jane. (2008). Platinum-group elements in the Merensky and JM Reefs : a review of recent studies. Geological Society of India, 72, (5), p. 595-609.
URL officielle: http://www.geosocindia.org/index.php/jgsi/article/...
The Merensky Reef of the Bushveld Complex (South Africa) and the J-M Reef of the Stillwater Complex (U.S.A.) are two layers enriched in platinum-group elements (PGE). In the last few years, several multidisciplinary studies were carried out on samples from these reefs. This includes: 3-D analysis by X-ray computed tomography, insitu minerals (base-metal sulphide, chromite and primary silicate) or fluid inclusions analysis using laser-ablation ICPMS, and detailed analysis of the platinum-group minerals (PGM). According to the results of these studies, in both reefs, the PGE are found either in solid-solution in the base-metal sulphides (BMS) or as PGM closely associated with the BMS. No PGE are present in the silicate or oxide lattices. Initially, the PGE were collected by a BMS sulphide liquid that interacted with silicate magma fertile in PGE. Then, the sulphide liquid may have percolated downward along vertical dilatancies formed during the compaction of the cumulate pile and may have stopped where the permeability is too low to allow it to further migrate. The PGE and base-metals were then redistributed either at a local scale (e.g. exsolution of the PGM from the BMS during cooling or partial desulphurization) or at a larger scale as observed in the J-M Reef. In this case, the Pd and to a lesser extent Pt may have been leached (possibly from the footwall) and then reprecipitated at the level of the reef by fluids (either liquid or vapour) during alteration and/or metamorphic events.
|Type de document:||Article publié dans une revue avec comité d'évaluation|
|Version évaluée par les pairs:||Oui|
|Sujets:||Sciences naturelles et génie > Sciences naturelles > Sciences de la terre (géologie, géographie)|
|Département, module, service et unité de recherche:||Départements et modules > Département des sciences appliquées > Unité d'enseignement en sciences de la Terre|
|Mots-clés:||sulphide, x-ray computed tomography, LA-ICP-MS, platinum-group minerals, Merensky Reef, J-M Reef|
|Déposé le:||12 déc. 2016 14:51|
|Dernière modification:||12 déc. 2016 14:51|
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