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TitreIron oxide copper-gold systems in the Great Bear Magmatic Zone: setting the stage for the next cycle of exploration
AuteurCorriveau, L; Hayward, N; Craven, J; Montreuil, J -F; Enkin, R; Potter, E; Jackson, V; Ootes, L; Lauzière, K; Roberts, B; Mumin, A H
Source39th Annual Yellowknife geocience forum, abstracts of talks and posters; par Fischer, B J; Watson, D M; Northwest Territories Geoscience Office, Yellowknife Geoscience Forum Abstracts Volume vol. 2011, 2011 p. 29 (Accès ouvert)
LiensOnline - En ligne
Séries alt.Secteur des sciences de la Terre, Contribution externe 20110329
RéunionYellowknife Geoscience Forum; Yellowknife; CA; Novembre 15-17, 2011
Documentpublication en série
ProvinceTerritoires du Nord-Ouest
SNRC85N; 86C; 86D; 86E; 86F; 86K; 86L
Lat/Long OENS-119.0000 -116.0000 67.0000 63.0000
Sujetsgisements minéraux; gîtes minéralogiques; minéralisation; oxydes de fer; cuivre; or; altération; altération hydrothermale; gisements minéraux hydrothermaux; prospection minière; Zone de Great Bear Magmatic ; géologie économique
ProgrammeGisements polymétalliques - Zone magmatique du Grand lac de l'Ours (T.N-O.), GEM : La géocartographie de l'énergie et des minéraux
Résumé(disponible en anglais seulement)
Following new geological and geophysical observations and modelling across the Great Bear magmatic zone (GBmz), the Geomapping for Energy and Minerals program and its partners of the South Wopmay Bedrock Mapping Project are now in a position to predict the types of mineral deposits that may be associated with the iron oxide copper-gold (IOCG) alteration and mineralizing systems. Using the framework of an IOCG alteration-to-deposit evolution model, we highlight potential targets for magnetite- and hematite-group IOCG deposits, iron oxide-apatite, albitite-hosted uranium and other types of deposits affiliated with IOCG systems across the magmatic zone and document their current geochemical anomalies and fingerprints.
We illustrate the diverse relations among mineralization types and provide examples of how the GBmz IOCG systems rival those of world-class deposits. We show that alteration mapping protocols, semi-quantitative geophysical modelling (integrating newly acquired aeromagnetic data, rock physical property and archival magnetic and gravity data) and magnetotelluric surveys are efficient predictive tools for mineral exploration and geological mapping. For example, alteration mapping in the most explored system within the magmatic zone, the Au-Co-Bi-Cu NICO deposit, led to the discovery of a new and significant multi-metal exploration target consisting of U-Th-Mo-Cu mineralization (see Potter et al., this volume). Combined pseudo gravity-based modelling and apparent density-based modelling of NICO geology allows a refinement of the distribution of potential iron oxide-rich alteration and potential mineralization in the area. At the regional scale, the pseudo gravity-based model is effective at highlighting known IOCG systems and has been utilized to direct bedrock mapping towards new targets which has led to new IOCG-type alteration and mineralization occurrences. The model shows large anomalies beneath the Paleozoic cover to the west of NICO/Sue Dianne, WNW of Fab, and SW of Hottah Lake; these and many other anomalies remain to be tested. A recent magnetotelluric survey has defined a significant anomaly below the NICO deposit, beyond currently available drill information. By overlaying known bedrock geology and geophysical models, potential mineralization can be predicted in terms of either iron oxide-apatite or magnetite- to hematite-group IOCG mineralization. Physical properties of 510 oriented samples from IOCG systems across the GBmz show a similar magnitude of and relationship between magnetic susceptibility and density of known IOCG deposits.
Current findings demonstrate that the GBmz remains significantly under explored both within virgin territories and areas with past-producing and recent mining infrastructures. We believe that by framing currently known alteration and mineralization within the IOCG alteration-to-deposit evolution model, the GBmz is ready for a new cycle of mineral exploration.