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TitreVariation in sulphide mineral chemistry in massive sulphide deposits, Bathurst Mining Camp, Canada: Implication for measuring volatile trace-elements by LA-ICP-MS and its application as a vectoring tool for the exploration of VMS deposits
AuteurSoltani Dehnavi, A; McFarlane, C R M; Lentz, D R
SourceL'Association géologique du Canada-L'Association minéralogique du Canada, Réunion annuelle conjointe, Recueil des résumés vol. 37, 2014 p. 259-260
LiensOnline - En ligne
Séries alt.Secteur des sciences de la Terre, Contribution externe 20140517
RéunionGAC-MAC 2014; Joint annual meeting of Geological Association of Canada and Mineralogical Association of Canada; Fredericton; CA; mai 21-23, 2014
Documentpublication en série
Mediaen ligne; numérique
SNRC21O/01; 21O/02SE; 21O/02NE; 21O/07SE; 21O/07NE; 21O/08; 21O/09; 21O/10SE; 21O/10NE; 21P/04; 21P/05; 21P/12
Lat/Long OENS -66.6667 -65.5000 47.7500 47.0000
Sujetsgîtes volcanogènes; sulfures; gîtes sulfureux; analyses des éléments en trace; induction électromagnétique; analyse par spectromètre de masse; méthodes analytiques; Camp minier de Bathurst; géochimie; minéralogie
ProgrammeÉtude des gîtes de sulfures massifs volcaniques, Initiative géoscientifique ciblée (IGC-4)
Résumé(disponible en anglais seulement)
Laser-Ablation ICP-MS is presently among the most efficient and precise micro-analytical techniques used for quantitative measurement of trace elements (ppm to ppb levels) in sulphide minerals. Advantages of this technique include in situ measurement capabilities, high-spatial resolution sampling, low detection limits, and cost efficiency. Laser-Ablation ICP-MS can be applied directly to standard polished thin sections, obviating special sample preparation. Methodologies for determining volatile trace-elements in sulphide mineral assemblages of Zn- Pb type massive sulphide deposits of the Bathurst Mining Camp (BMC) have been examined and developed. The improved analytical protocols include an evaluation of optimized ablation conditions, choice of external standards, and internal standardization and data reduction strategies. The results show that all forms of pyrite in the BMC are arsenian in nature with As incorporating as the main substitution in pyrite, ranging from 2.2 ppm to 2.58%. Arsenic also locally occurs as a trace-element substitution in sphalerite and chalcopyrite. Cadmium occurs in sphalerite, galena, and pyrite with the former hosting the highest concentrations (845-1996 ppm Cd). Among the sulphide mineral assemblages characteristic of different mineralogical and chemical facies, sphalerite is the dominant host for Hg (1.4-174.9 ppm), followed by pyrite, and chalcopyrite. Indium is locally elevated in sphalerite, chalcopyrite, and pyrite. Antimony abundances are more variable, but commonly occur in galena, as well as pyrite, where it strongly correlates with As. Finally, Tl is variably distributed among the different phases, but is locally enriched in pyrite (0.06-338 ppm) and galena (1.13-32 ppm). There is a strong textural control on the volatile element concentrations in massive sulphide deposits of the BMC. ?Primary' pyrite (i.e., pre-deformational) in the Restigouche deposit has higher volatile element concentrations than ?secondary' (i.e., syn-deformational and post-deformational) pyrite. In contrast, some deposits with primary enrichment in Au, Sb, Hg, and Tl, such as Louvicourt also, display high contents of volatile trace-elements in late recrystallized pyrite. Therefore, upgrading trends in the primary pyrite suggests that metamorphism and syn-deformational processes do not have major effect on redistribution of these elements; whereas, the signature of liberation of these elements in recrystallized pyrite offers association to the origin of the ore deposition. Hence, these primary and secondary dispersions of volatile trace elements potentially can be used as a trace-element vectoring tool in exploration for massive sulphide deposits.