| Titre | Banded iron formation-associated gold deposits |
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| Auteur | Mercier-Langevin, P; Dubé, B |
| Source | Ressources, Mines et Industrie 2022 p. 22-31 |
| Liens | Online - En ligne
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| Image |  |
| Année | 2022 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20210359 |
| Éditeur | Groupe Tertio Inc. |
| Document | publication en série |
| Lang. | anglais |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Nunavut |
| Sujets | formations ferrifères; or |
| Illustrations | photographies; diagrammes; représentations schématiques |
| Programme | Initiative géoscientifique ciblée (IGC-6) Systèmes minéralisés |
| Diffusé | 2022 06 18 |
| Résumé | (disponible en anglais seulement)
Several major gold deposits in Nunavut, Ontario and Quebec are associated with banded iron formations, which are iron-rich (?15 wt.% Fe) sedimentary units in
submarine volcano-sedimentary sequences. While iron-rich strata may be slightly enriched in trace metals produced by submarine volcanism and hydrothermal activity, the gold deposits contained in these units are epigenetic, meaning they are
significantly younger than the host rocks. The presence of gold is due to the circulation of hydrothermal fluids generated at depth in the Earth's crust during deformation, where an increase in the thermal gradient (metamorphism) liberates fluids and
gold. This gold-bearing fluid is transported higher in the crust and preferentially channelled through conduits and structural traps (e.g., faults, folds and dilatational zones), where the chemistry of the iron formations, which are particularly
reactive to the fluids, causes destabilization and precipitation of the gold in solution. Given that this process is closely related to tectonism and the deformation and metamorphism of rocks at different scales, these deposits belong to a category
of gold deposits defined as orogenic. While the geometry of the deposits associated with iron formations can be particularly complex, complicating exploration and mining in some cases, iron formations are attractive exploration targets in remote
areas due to their potential to host high-grade and high-tonnage gold deposits. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Cette contribution résume les principales caractéristiques géologiques des gisements d'or qui sont associés à des unités de roches sédimentaires
riches en fer appelées formations de fer rubanées; un style de minéralisation aurifère commun au Canada. |
| GEOSCAN ID | 329071 |
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