| Titre | Finding deeper porphyry Cu deposits in the Canadian Cordillera using epidote chemistry |
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| Auteur | Plouffe, A ;
Kjarsgaard, I; Petts, D; Ferbey, T |
| Source | AME Roundup 2020, technical sessions abstract guide; 2020 p. 26  Accès ouvert |
| Liens | Online - En ligne (complete volume - volume
complet, PDF, 53.0 MB)
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| Image |  |
| Année | 2020 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20190334 |
| Éditeur | Association for MIneral Exploration |
| Réunion | AME Roundup 2020; Vancouver, BC; CA; janvier 20-23, 2020 |
| Document | livre |
| Lang. | anglais |
| Media | en ligne; numérique |
| Province | Colombie-Britannique |
| SNRC | 93B/07; 93B/08; 93B/09; 93B/10 |
| Lat/Long OENS | -123.0000 -122.0000 52.7500 52.2500 |
| Sujets | gisements minéraux; cuivre porphyrique; altération hydrothermale; altération; épidote; prospection minière; méthodes d'exploration; dépôts glaciaires; tills; erosion glaciaire; profils de dispersion;
directions du transport de la glace; géologie du substratum rocheux; lithologie; roches ignées; roches volcaniques; volcanoclastique; Cordillère canadienne; Groupe de Nicola ; géologie économique; géochimie; géologie des dépôts
meubles/géomorphologie; Sciences et technologie; Nature et environnement; Phanérozoïque; Mésozoïque; Trias |
| Programme | Initiative géoscientifique ciblée (IGC-5) Systèmes minéralisés - intrusions/porphyriques |
| Diffusé | 2020 01 27 |
| Résumé | (disponible en anglais seulement)
The next generation of porphyry Cu deposits to be discovered in the Canadian Cordillera are likely to be buried by glacial sediments and be located deeper than
the known deposits. To overcome this 'poor-exposure and depth' challenge, we are investigating the composition of epidote, a mineral common in alteration zones that surround porphyry systems, as a mean of detecting Cu ore at depth. Epidote is a
resistant mineral which can be dispersed from its bedrock source by detrital processes. In previous studies, we demonstrated that epidote is more abundant in till near porphyry mineralization compared to surrounding background regions. The
distribution patterns of epidote in till result from glacial erosion and dispersal from the porphyry alteration zones. Consequently, identification of an epidote anomaly in till could become a mean of detecting porphyry Cu mineralization covered by
glacial sediments. In the Canadian Cordillera, the challenge is then to discriminate between epidote derived from porphyry hydrothermal alteration versus epidote sourced from barren rocks. In the Cordillera, metamorphic epidote commonly occurs within
Upper Triassic Nicola volcanic and volcaniclastic rocks. We analyzed the composition of epidote from porphyry alteration zones and Nicola rocks by LA-ICP-MS. Hafnium, Th, Sc, Cr, and Y occur in higher concentrations in epidote of Nicola rocks
compared to epidote from porphyry alteration zones. In addition, the As and Sb content of hydrothermal alteration epidote is higher than in metamorphic epidote. Epidote grains recovered from till in the region of three porphyry deposits have a
composition diagnostic of porphyry alteration (i.e. lower Hf, Th, Sc, Cr, and Y and higher As and Sb concentrations relative to Nicola epidote). We conclude that the composition of epidote in detrital sediments within a prospective geological setting
can provide an indication of buried porphyry Cu mineralization. |
| Sommaire | (Résumé en langage clair et simple, non publié)
La demande en cuivre à l'échelle mondiale augementera avec l'électrification des moyens de transport. La présentation expliquera comment
explorer pour des gîtes cuprifères plus profonds pour répondre à nos besoins futurs. En analysant la composition d'un minéral commun, l'épidote, nous pouvons détecter une zone étendue qui entoure les zones enrichis en cuivre dans la roche. Cette zone
est une cible beaucoup plus grande que la zone enrichie en cuivre. |
| GEOSCAN ID | 321399 |
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