| Titre | New U-Pb geochronology from the Blake River Group, Abitibi Subprovince, Québec: implications for geological interpretations and base metal exploration |
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| Auteur | McNicoll, V; Goutier, J; Dubé, B; Mercier-Langevin, P; Ross, P; Dion, C; Monecke, T; Legault, M; Percival, J; Gibson, H |
| Source | Archean volcanism, magmatism and ore deposits; par Mercier-Langevin, P (éd.); Hannington, M (éd.); Gibson, H (éd.); Houlé, M (éd.); Dubé, B (éd.); Monecke, T (éd.); Goutier, J (éd.); Economic geology and
the bulletin of the Society of Economic Geologists vol. 109, no. 1, 2014 p. 27-59, https://doi.org/10.2113/econgeo.109.1.27 |
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| Année | 2014 |
| Séries alt. | Secteur des sciences de la Terre, Contribution externe 20110274 |
| Éditeur | Society of Economic Geologists |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.2113/econgeo.109.1.27 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Québec; Ontario |
| SNRC | 32D |
| Région | Rouyn-Noranda |
| Lat/Long OENS | -80.0000 -78.5000 49.0000 48.0000 |
| Sujets | datations au uranium-plomb; roches volcaniques; gisements minéraux; minéralisation; Archéen; roches volcaniques; roches plutoniques; gîtes volcanogènes; gîtes sulfureux; Groupe de Blake River ; Ceinture
d'Abitibi Greenstone ; Mine Horne ; Mine Millenbach ; Mine Amulet ; Formation de Bousquet ; géochronologie; minéraux métalliques; Précambrien |
| Illustrations | cartes géologiques généralisées |
| Programme | Initiative géoscientifique ciblée (IGC-3), 2005-2010 Abitibi IGC-3 |
| Programme | Initiative géoscientifique ciblée (IGC-4) Étude des gîtes de sulfures massifs volcaniques |
| Programme | Initiative géoscientifique ciblée (IGC-4) Étude des gîtes d'or |
| Diffusé | 2013 11 19 |
| Résumé | (disponible en anglais seulement)
The 2704 to 2695 Ma Blake River Group in the southern Abitibi greenstone belt comprises a well preserved submarine volcanic sequence that hosts a large number
of VMS and important Au-rich VMS deposits, including the world-class Horne and LaRonde-Penna deposits. Establishing precise chronostratigraphic control on the VMS deposits within the Blake River Group is critical because numerous distinct events took
place within a period of 9 m.y. Nineteen new high-precision U-Pb ages temporally constrain the host rocks of many polymetallic VMS deposits and associated synvolcanic intrusions, demonstrating that these VMS deposits formed throughout the protracted
volcanic evolution of the entire group.
Ages on host rocks of the Horne (2702.2 ± 0.9 Ma), Quemont (2702.0 ± 0.8 Ma), and Fabie (2701.9 ± 0.9 Ma) deposits reveal that they are among the oldest VMS deposits in the Blake River Group. The giant
Horne Au-rich VMS deposit had already formed when the Cu-Zn deposits of the Noranda mine sequence, including Millenbach and Amulet, were generated at ~2698 Ma and is thus unrelated, consistent with its different volcanological setting and metal
content. Large Au-rich VMS deposits of the Bousquet Formation, including LaRonde Penna and Bousquet 2-Dumagami, were formed at 2698 to 2697 Ma and are distinctly younger than the Horne and Quemont deposits. There were, therefore, two major
time-stratigraphic intervals within the Blake River Group that were favorable for the formation of Au-rich VMS deposits. Rhyolite hosting the large Bouchard-Hébert VMS deposits yielded an age of 2695.8 ± 0.8 Ma.
Important mineralizing events in
the Blake River Group occur at ca. 2-m.y. intervals apart and are associated with major magmatic episodes. Recognition of specific time-stratigraphic intervals for different styles of mineralization and geologic settings is essential to improve
exploration models within the Blake River Group and for similar volcanic assemblages elsewhere in the Archean. |
| GEOSCAN ID | 289583 |
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