| Titre | Ore mineralogy, pyrite chemistry, and S isotope systematics of magmatic-hydrothermal Au mineralization associated with the Mooshla Intrusive Complex (MIC), Doyon-Bousquet-LaRonde mining camp, Abitibi
greenstone belt, Québec |
| Télécharger | Téléchargement (publication entière) |
| |
| Licence | Veuillez noter que la Licence du gouvernement
ouvert - Canada remplace toutes les licences antérieures. |
| Auteur | Neyedley, K; Hanley, J J; Mercier-Langevin, P; Fayek, M |
| Source | Targeted Geoscience Initiative 5: grant program final reports (2018-2020); par Targeted Geoscience Initiative Coordination Office; Commission géologique du Canada, Dossier public 8755, 2021 p. 129-148,
https://doi.org/10.4095/328985  Accès ouvert |
| Année | 2021 |
| Éditeur | Ressources naturelles Canada |
| Document | dossier public |
| Lang. | anglais |
| DOI | https://doi.org/10.4095/328985 |
| Media | en ligne; numérique |
| Référence reliée | Cette publication est contenue dans Targeted
Geoscience Initiative 5: grant program final reports (2018-2020) |
| Formats | pdf |
| Province | Québec |
| SNRC | 32D/02NE; 32D/07SE |
| Lat/Long OENS | -78.5903 -78.5011 48.2822 48.2489 |
| Sujets | prospection minière; gisements minéraux; or; cuivre; métaux de base; gîtes volcanogènes; gîtes sulfureux; gisements filoniens; gisements porphyriques; gîtes épithermaux; genèse des minerais;
minéralisation; pyrite; etudes isotopiques; isotopes; soufre; ceintures de roche verte; cadre tectonique; magmatisme; intrusions; système hydrothermal; dynamique des fluides; analyses pétrographiques; assemblages de minéraux; sulfures; géochimie des
éléments en trace; composition en vrac; analyse par spectromètre de masse; gîtes minéralogiques; Archéen; Camp minier de Doyon-Bousquet-Laronde; Ceinture d'Abitibi Greenstone ; géologie économique; minéralogie; géochimie; tectonique; Sciences et
technologie; Nature et environnement; Précambrien |
| Illustrations | cartes de localisation; cartes géolscientiques généralisées; tableaux; photographies; images numériques; photomicrographies; graphiques |
| Programme | Initiative géoscientifique ciblée (IGC-5) Gestion de la connaissance de IGC |
| Diffusé | 2021 10 27 |
| Résumé | (disponible en anglais seulement)
The Mooshla Intrusive Complex (MIC) is an Archean polyphase magmatic body located in the Doyon-Bousquet-LaRonde (DBL) mining camp of the Abitibi greenstone
belt, Québec. The MIC is spatially associated with numerous gold (Au)-rich VMS, epizonal 'intrusion-related' Au-Cu vein systems, and shear zone-hosted (orogenic?) Au deposits. To elucidate genetic links between deposits and the MIC, mineralized
samples from two of the epizonal 'intrusion-related' Au-Cu vein systems (Doyon and Grand Duc Au-Cu) have been characterized using a variety of analytical techniques.
Preliminary results indicate gold (as electrum) from both deposits occurs
relatively late in the systems as it is primarily observed along fractures in pyrite and gangue minerals. At Grand Duc gold appears to have formed syn- to post-crystallization relative to base metal sulphides (e.g. chalcopyrite, sphalerite,
pyrrhotite), whereas base metal sulphides at Doyon are relatively rare. The accessory ore mineral assemblage at Doyon is relatively simple compared to Grand Duc, consisting of petzite (Ag3AuTe2), calaverite (AuTe2), and hessite (Ag2Te), while
accessory ore minerals at Grand Duc are comprised of tellurobismuthite (Bi2Te3), volynskite (AgBiTe2), native Te, tsumoite (BiTe) or tetradymite (Bi2Te2S), altaite (PbTe), petzite, calaverite, and hessite.
Pyrite trace element distribution maps
from representative pyrite grains from Doyon and Grand Duc were collected and confirm petrographic observations that Au occurs relatively late. Pyrite from Doyon appears to have been initially trace-element poor, then became enriched in As, followed
by the ore metal stage consisting of Au-Ag-Te-Bi-Pb-Cu enrichment and lastly a Co-Ni-Se(?) stage enrichment. Grand Duc pyrite is more complex with initial enrichments in Co-Se-As (Stage 1) followed by an increase in As-Co(?) concentrations (Stage 2).
The ore metal stage (Stage 3) is indicated by another increase in As coupled with Au-Ag-Bi-Te-Sb-Pb-Ni-Cu-Zn-Sn-Cd-In enrichment. The final stage of pyrite growth (Stage 4) is represented by the same element assemblage as Stage 3 but at lower
concentrations. Preliminary sulphur isotope data from Grand Duc indicates pyrite, pyrrhotite, and chalcopyrite all have similar delta-34S values (~1.5 ± 1 permille) with no core-to-rim variations.
Pyrite from Doyon has slightly higher delta-34S
values (~2.5 ± 1 permille) compared to Grand Duc but similarly does not show much core-to-rim variation. At Grand Duc, the occurrence of Au concentrating along the rim of pyrite grains and associated with an enrichment in As and other metals
(Sb-Ag-Bi-Te) shares similarities with porphyry and epithermal deposits, and the overall metal association of Au with Te and Bi is a hallmark of other intrusion-related gold systems. The occurrence of the ore metal-rich rims on pyrite from Grand Duc
could be related to fluid boiling which results in the destabilization of gold-bearing aqueous complexes. Pyrite from Doyon does not show this inferred boiling texture but shares characteristics of dissolution-reprecipitation processes, where metals
in the pyrite lattice are dissolved and then reconcentrated into discrete mineral phases that commonly precipitate in voids and fractures created during pyrite dissolution. |
| Sommaire | (Résumé en langage clair et simple, non publié)
L'Initiative des géosciences ciblées (IGC) est un programme fédéral collaboratif. Ce programme fournit à l'industrie ce qui est requis pour la
prochaine génération des connaissances géoscientifiques et des techniques novatrices. Le résultat est l'identification des dépôts de minéraux en profondeur. Ce compendium est le résultat des récipiendaires des subventions d'IGC 2018-2020. |
| GEOSCAN ID | 328985 |
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